HK1228495B - Apparatus and method for selectively inspecting component sidewalls - Google Patents

Description

Apparatus and method for selectively inspecting part sidewalls

Technical Field

Aspects of the present disclosure relate to apparatus and methods for inspecting exterior surfaces or sides of components including component sidewalls, wherein the sidewall inspection can occur in association with selectively directing illumination along a light travel path to some or all of the component sidewalls such that the illumination is normally incident on those sidewalls, and directing light reflected from the sidewalls such that an image capture device can capture an image of the sidewalls.

Background Art

Optical inspection for defects on the extrinsic, external, or outer surfaces and/or structures of a component of a semiconductor device, such as a semiconductor die or package, can be performed by "five side inspection." Five side inspection involves directing illumination toward five sides of a component, such as a bottom surface of the component and four side walls of the component, which by this definition of side will be the bottom of the component when the component is secured on a sixth side (e.g., by a pick and place device). In association with five side optical inspection, illumination can be directed toward the bottom surface of the component, thereby facilitating the capture of an image of the bottom surface; and illumination can be directed toward the side walls of the component, thereby facilitating the capture of an image of the side walls of the component. To capture the image, incident illumination reflected from the bottom surface and/or side walls of the component can be directed toward an optical assembly, such as a lens assembly, and an image capture device.

FIG1A is a schematic diagram illustrating a portion of a conventional five-side inspection apparatus, wherein a component 20 is held in a bottom surface inspection position by a component holder 50 (e.g., a pick and place device) such that the component resides vertically in the bottom surface inspection position, and also between a set of reflectors or prisms 130 a-b. Although FIG1A shows only two prisms 130 a-b, a typical five-side inspection system includes four prisms 130, i.e., one prism corresponding to one of the four side walls of the component.

Brightfield illuminator 100 outputs brightfield illumination in an upward direction, which passes through beam splitter 110 as it travels toward component 20. Some of the brightfield illumination strikes and is reflected by the component bottom surface and/or surface features corresponding thereto, such as solder balls, and is reflected directly therefrom in a downward direction toward beam splitter 110. Upon reaching reflective surface 112 of the beam splitter, this downward-traveling brightfield illumination is redirected toward an image capture device (not shown) so that an image corresponding to the component bottom surface can be captured.

Some of the brightfield illumination output by brightfield illuminator 100 additionally reaches each prism 130a-b. The lateral optical path between prisms 130a-b is not blocked or interrupted by component 20 because the component is positioned above prisms 130a-b. Thus, upon reaching any given prism 130a-b, the brightfield illumination is redirected in a lateral direction toward the opposing prism 130b-a, after which it is redirected again in a downward direction toward beam splitter 110. Upon reaching the reflective surface 112 of the beam splitter, the illumination, having traveled along the optical path through prisms 130a-b, is further directed toward the image capture device and forms the outer portion of the image captured thereby.

FIG1B is a representative inspection image corresponding to a captured bottom surface of a component when the component is secured in a bottom surface inspection position corresponding to the inspection configuration shown in FIG1A. As indicated in FIG1B, bright field illumination having passed through prisms 130a-b appears as a bright or very bright peripheral portion of the captured image, and the bottom surface of the component and structures corresponding thereto appear within the in-focus central region of the captured image.

When the component is held in the bottom surface inspection position, after image capture has occurred, the component holder 50 vertically lowers or inserts the component 20 into the sidewall inspection position so that the component 20, which resides between the prisms 130a-b and the sidewall of the component, falls into the lateral optical path between the prisms 130a-b. Thus, when the component is positioned in the sidewall inspection position, the component 20 acts as a barrier to some of the illumination traveling from one prism 130a-b toward the other prisms 130b-a.

More specifically, FIG1C is a schematic diagram illustrating a portion of a conventional five-sided inspection apparatus, wherein part 20 is held in a sidewall inspection position by part holder 50 such that the vertical extent or height/thickness of the part is within the vertical extent or height limits of prisms 130a-b. As previously described, when brightfield illuminator 100 outputs brightfield illumination, the brightfield illumination passes through beam splitter 110 as it travels in an upward direction toward part 20. Some of the brightfield illumination strikes and is reflected by the bottom surface of the part and/or surface features corresponding thereto, such as solder balls, and is then directly reflected in a downward direction toward beam splitter 110. Upon reaching reflective surface 112 of beam splitter 110, this downwardly traveling illumination corresponding to the bottom surface of the part is redirected toward the image capture device.

Some of the upwardly traveling bright field illumination additionally reaches a set of prisms 130a-b. The prisms 130a-b reflect and redirect the bright field illumination so that it travels laterally toward the part sidewalls. A portion of this laterally traveling illumination is reflected back by the part sidewalls toward the prisms 130a-b, which then reflect and redirect the illumination in a downward direction toward the beam splitter 110, where the beam splitter's reflective surface 112 redirects the illumination, which has been reflected by the part sidewalls, toward the image capture device, so that when the part is positioned in the sidewall inspection position, an image corresponding to each of the part's sidewalls can be captured simultaneously with the capture of the illumination corresponding to the part's bottom surface/bottom surface structure.

FIG1D is a representative inspection image captured when part 20 is secured in a sidewall inspection position, wherein the central image area corresponds to bright field illumination reflected by the bottom surface of the part and/or structure being transported thereby, and the respective image areas to the left, right, and bottom of the image correspond to the sidewalls of the part.

The image captured when the component 20 is held in the bottom surface inspection position provides an in-focus image region corresponding to the center of the component's bottom surface and a bright peripheral region that contains or conveys essentially no useful information about the component's sidewalls. The image captured when the component 20 is held in the sidewall inspection position provides an in-focus peripheral image region corresponding to the component's sidewalls and an at least slightly defocused central image region corresponding to the component's bottom surface. This defocusing of the central image region within the captured image occurs when the component 20 is held in the sidewall inspection position due to the vertical offset between the bottom surface inspection position and the sidewall inspection position.

Specifically, the vertical offset between the bottom surface inspection position and the sidewall inspection position is selected so that the optical path length between the front surface of the component and/or the mechanism transported thereby (e.g., solder balls) and the imaging plane of the image capture device is equal to or approximately equal to the optical path length between the sidewall of the component and the imaging plane of the image capture device. Thus, when the component 20 is inserted from the bottom surface inspection position to the sidewall inspection position, no focusing (defocusing) operation needs to occur between the capture of images, which helps inspection throughput.

For inspection purposes, a single composite image is typically generated from images captured when the component 20 is secured in the bottom surface inspection position and images captured when the component 20 is secured in the sidewall inspection position. A composite image is generated by combining or digitally "stitching" together (a) a focused central region of the image corresponding to the bottom surface of the component captured when the component 20 is secured in the bottom surface inspection position and (b) a focused peripheral or outer region corresponding to the sidewall of the component captured when the component 20 is secured in the sidewall inspection position. FIG. 1E provides a representative composite image generated by combining or digitally stitching together central and peripheral portions of the bottom surface inspection image with the sidewall inspection image, respectively. FIG. 1F illustrates a portion of a composite image corresponding to the sidewall of the component.

In conventional five-sided inspection apparatuses, the vertical extent of prism 130 significantly exceeds the vertical extent of the component sidewall. Consequently, when component 20 is positioned in the sidewall inspection position, the upward-traveling brightfield illumination output by brightfield illuminator 100, incident on prism 130 and directed and reflected by prism 130 toward the component sidewall, is vertically distributed across a spatial extent or region that is greater than, or significantly greater than, the vertical extent of the component sidewall. Consequently, a significant amount of the brightfield illumination output by brightfield illuminator 100 that has been redirected along a lateral path by a given prism 130 does not impinge on the component sidewall, thereby completely missing or bypassing the component. This brightfield illumination simply travels uninterrupted to the opposing prism 130 and is reflected along a downward path to beam splitter 110, where it forms part of the captured image, where the brightfield illumination, following a direct prism-to-prism optical path, appears as a bright, bright white background against the captured image of the component sidewall, as indicated in FIG1D .

This brightfield illumination, which carries no optical information about component defects, is directed along a lateral optical path perpendicular to the component sidewall, but is not incident on the component sidewall and simply replaces the multiple prismatic reflections experienced along the optical path, excluding reflections from the component itself or its associated structures. Therefore, this illumination can be referred to as extraneous brightfield illumination. This extraneous brightfield illumination is sufficiently intense or bright that its presence in the captured sidewall image can cause "optical crosstalk," which can visually "wash out" the appearance of shadows or very small defects (e.g., micro-defects such as hairline cracks or fissures) in the sidewall image, thereby interfering with or limiting the extent to which image processing algorithms can detect micro-defects on the component sidewall. In other words, this extraneous brightfield illumination can reduce the contrast and clarity of the captured sidewall image. This is particularly significant as integrated circuits continue to become smaller, and the associated defects are also smaller, increasing the need for improved image contrast and clarity. Optical crosstalk tends to reduce the visibility and optical resolution or clarity of very small cracks (eg, particularly cracks having a size or dimension less than or equal to about 10 μm).

There is a need to improve the way that part sidewalls are illuminated and images of the part sidewalls are captured in five side inspection devices.

Summary of the Invention

One aspect of the present disclosure relates to a multi-sided inspection apparatus that can capture images of a bottom surface and/or a sidewall of a component, wherein the apparatus is configured for inspecting a surface of a component including a sidewall of the component, the apparatus comprising: a set of sidewall illuminators configured to output sidewall illumination; a set of sidewall beam splitters configured to: (a) receive sidewall illumination output by the set of sidewall illuminators; (b) transmit the sidewall illumination output by the set of sidewall illuminators through the set of sidewall beam splitters so that at least some of the sidewall illumination is incident on the sidewall of the component when the component is positioned in a sidewall inspection position where the sidewall of the component interrupts at least some of the optical paths between the sidewall beam splitters within the set of sidewall beam splitters; (c) receive sidewall illumination reflected from the sidewall of the component when the component is positioned in the sidewall inspection position; and (d) redirect the reflected sidewall illumination along an optical path corresponding to a lens assembly and an image capture device.

Another important aspect of the present disclosure relates to methods for eliminating extraneous illumination that passes from a sidewall beam splitter on one side of a component to a sidewall beam splitter on the opposite side of the component, which contributes to crosstalk and tends to reduce the visibility of details and the clarity of ultrafine defects in captured sidewall images of the component. A number of embodiments use different techniques to eliminate extraneous light that contributes to crosstalk in part sidewall images.

In one embodiment, a method for eliminating crosstalk includes the use of a suitable polarizer or combination of polarizers coupled to each pair of opposing sidewall beam splitters and configured using techniques known in the art such that (i) while each polarizing beam splitter assembly (a combination of a polarizer and a beam splitter) on one side of a component sidewall allows illumination generated by its corresponding sidewall illuminator to pass therethrough with a particular direction of polarization, the polarization of the illumination passing through each pair of opposing beam splitters is different, and (ii) polarized illumination that passes through the polarizing beam splitter from one side of the component (without being reflected or blocked by the component sidewall) and passes over the component to the opposing polarizing beam splitter assembly on the opposite side of the component will be absorbed or directed away by the polarizing beam splitter assembly. As a result, each of the opposing sidewalls of the component will be illuminated with light of a different direction of polarization, and extraneous polarized illumination that is not blocked by the component sidewall and passes to the polarizing beam splitter assembly on the opposite side of the component will be absorbed or eliminated by the receiving polarization beam splitter. This arrangement can be applied to each pair of opposing beam splitters so that multiple sidewall images of a component can be captured without crosstalk.

In one example, the apparatus includes at least one pair of sidewall illuminators, wherein the two sidewall illuminators are disposed opposite each other relative to the sidewall inspection location. Additionally or alternatively, the set of sidewall beam splitters includes at least one pair of sidewall beam splitters disposed oppositely on different sides of the sidewall inspection region relative to an axis defined by the sidewall inspection region. The at least one pair of oppositely disposed sidewall beam splitters may include a first sidewall beam splitter and a second sidewall beam splitter, wherein the first sidewall beam splitter is configured to pass therethrough first sidewall illumination having a first optical wavelength or a first optical bandwidth, and the second sidewall beam splitter is configured to pass therethrough second sidewall illumination having a second, different optical wavelength or a second optical bandwidth. The first side wall beam splitter is configured to receive and redirect each of the first reflected side wall illumination from the first component side wall and the second external side wall illumination passed through the second side wall beam splitter, which has traveled across the side wall inspection area, and the second side wall beam splitter is configured to receive and redirect each of the second reflected side wall illumination from the second component side wall and the first external side wall illumination passed through the first side wall beam splitter, which has traveled across the side wall inspection area, wherein the first component side wall and the second component side wall face the first side wall beam splitter and the second side wall beam splitter, respectively, so that the first component side wall and the second component side wall can be considered to be relatively oriented or directed relative to each other and the first axis.

The apparatus may include an image capture device and a processing unit, wherein the image capture device is configured to (a) capture a single image in a single image capture operation, the image capture device including a first image area corresponding to a first reflected sidewall illumination and a second extraneous sidewall illumination, and a second image area corresponding to the second reflected sidewall illumination and the first extraneous sidewall illumination, and (b) generate image data corresponding to the single image; the processing unit is configured to process the image data such that pixel values corresponding to the second extraneous sidewall illumination are digitally filtered from the image data corresponding to the first image area, and pixel values corresponding to the first extraneous sidewall illumination are digitally filtered from the image data corresponding to the second image area.

A set of side wall illuminators may include a plurality of side wall illuminators, wherein (a) each side wall illuminator outputs illumination at the same optical center wavelength or bandwidth, or (b) a first subset of the side wall illuminators outputs illumination having an optical center wavelength or bandwidth that is different from the illumination output by a second subset of the side wall illuminators. The side wall illuminators may be activated simultaneously; or a particular subset of the side wall illuminators within the set of side wall illuminators may be selectively activated to output side wall illumination while other subsets of the side wall illuminators within the set of side wall illuminators remain inactive. The apparatus may also include a bright field illuminator and/or a dark field illuminator configured to selectively direct illumination toward a bottom surface or a bottom surface and a side wall of a component disposed in a side wall inspection position, wherein the component side wall extends between the bottom surface and the component bottom surface.

The apparatus may include an image capture beam splitter configured to (a) receive illumination output by a bright field illuminator and pass the bright field illumination therethrough; (b) receive bright field and/or reflected dark field illumination reflected from a bottom surface and/or sidewalls of a component; (c) receive sidewall illumination reflected from sidewalls of the component that has been redirected by a set of sidewall beam splitters; and (d) redirect the received reflected illumination (b) corresponding to an optical path toward a lens assembly and (c) along the optical path.

The apparatus also includes an image capture device configured to receive illumination output by the lens assembly, where the image capture device may include a monochrome image sensor or a color image sensor.

The apparatus may further include a component holder configured to selectively position the component in a sidewall inspection position or a bottom surface inspection position only, wherein component obstruction of an optical path between each sidewall beam splitter is avoided. In one example, the component holder is configured to selectively position the component held thereby in a plurality of sidewall inspection positions within an inspection area definable between the plurality of sidewall beam splitters, the sidewall inspection positions including a first sidewall inspection position in which a component center point is positioned closer to a first subset of sidewall beam splitters than to a second, different, subset of sidewall beam splitters, and a second sidewall inspection position in which a component center point is positioned closer to a second subset of sidewall beam splitters than to the first subset of sidewall beam splitters.

The apparatus may include a control unit configured to selectively control activation of a subset of side wall illuminators within a set of side wall illuminators, positioning the component at one or more inspection positions within an inspection area, and capturing one or more images of a surface of the component by an image sensor.

According to one aspect of the present disclosure, a process for inspecting one or more sides of a component, such as a side surface/sidewall of the component, includes: providing a set of sidewall illuminators configured to output sidewall illumination at one or more central wavelengths or wavelength ranges; providing a set of sidewall beamsplitters configured to receive sidewall illumination output by the set of sidewall illuminators; positioning the component at a first sidewall inspection position such that the component sidewall at least partially blocks at least some optical paths between the sidewall beamsplitters within the set of sidewall beamsplitters; directing the sidewall illumination output by the set of sidewall illuminators toward the component sidewall by passing the sidewall illumination received by the set of sidewall beamsplitters therethrough; receiving sidewall illumination output by the set of sidewall beamsplitters at a plurality of component sidewalls while the component resides in the first sidewall inspection position; receiving sidewall illumination reflected from a plurality of component sidewalls at the plurality of sidewall beamsplitters; and redirecting the reflected sidewall illumination received by the plurality of sidewall beamsplitters along an optical path corresponding to an image capture device.

The process may include selectively directing sidewall illumination toward a first subset of component sidewalls while avoiding directing sidewall illumination toward a second subset of component sidewalls during a first image capture operation; and/or selectively directing sidewall illumination toward a second subset of component sidewalls while avoiding directing sidewall illumination toward the first subset of component sidewalls during a second image capture operation.

The process may include capturing a first image (e.g., when the component is centered within a sidewall inspection region or positioned within a first sidewall inspection position within a sidewall inspection region that may be defined between a set of sidewall beam splitters, which may be a first off-center sidewall inspection position), the first image including a pixel area corresponding to a first subset of the sidewalls of the component; and capturing a second image (e.g., when the component is centered within the sidewall inspection region or positioned within a second, different sidewall inspection position within the sidewall inspection region, which may be a second off-center sidewall inspection position), the second image including a pixel area corresponding to a second subset of the sidewalls of the component. When the component is positioned at the first sidewall inspection position, the center point of the component may be closer to the first subset of sidewall beam splitters; and when the component is positioned at the second sidewall inspection position, the center point of the component may be closer to a second, different set of sidewall beam splitters.

A composite image may be generated by digitally stitching together portions of a first image corresponding to a first subset of component sidewalls and portions of a second image corresponding to a second subset of component sidewalls. Automated inspection operations may be performed on the individual captured images and/or the composite image.

The sidewall illumination may include first and second sidewall illumination, and the reflected sidewall illumination may correspondingly include first and second reflected sidewall illumination, wherein the first and second sidewall illumination exhibit different bandwidth-limited optical wavelength ranges, and/or the first and second reflected sidewall illumination exhibit different bandwidth-limited optical wavelength ranges. The process may include capturing an image as a single view (e.g., a single image captured in a single image capture operation), the image including a plurality of different pixel regions, each pixel region corresponding to each pixel region of a different component sidewall, each pixel region corresponding to at least two different bandwidth-limited optical path ranges.

The process may include performing a wavelength-separated calibration procedure prior to capturing an image to determine at least one calibration factor that can be applied to a pixel region corresponding to a particular component sidewall to determine, reduce, eliminate, or effectively eliminate the effects of extraneous sidewall illumination in the captured image.

The process may include capturing at least one image including pixel areas corresponding to at least two sidewalls of the component while the component is residing in a sidewall inspection position; shifting the component to a bottom surface-only inspection position where component interruption of an optical path between each sidewall beam splitter is avoided; directing brightfield illumination and/or darkfield illumination toward a bottom surface of the component while the component is residing in the bottom surface-only inspection position; and capturing an image corresponding to the bottom surface of the component.

According to one aspect of the present disclosure, a process for inspecting a component having multiple side walls, the multiple side walls including a first component side wall and a second component side wall facing opposite directions relative to each other along a first axis, the method including: positioning the component at a side wall inspection position within a side wall inspection area between a plurality of side wall beam splitters, the plurality of side wall beam splitters including a first side wall beam splitter and a second side wall beam splitter disposed on opposite sides of the side wall inspection area along the first axis; simultaneously transmitting side wall illumination through the plurality of side wall beam splitters so that the first component side wall and the second component side wall receive first incident side wall illumination and second incident side wall illumination thereon, respectively, at different optical center wavelengths or different optical bandwidths; receiving at the first side wall beam splitter (a) first reflected side wall illumination that travels away from the first component side wall after the first incident side wall illumination arrives at or is reflected from it, and (b) second external side wall illumination that has been transmitted through the second side wall beam splitter across the side wall inspection area; and receiving at the second side wall beam splitter a device for receiving (c) second incident sidewall illumination impinging thereon and second reflected sidewall illumination traveling away from the second component sidewall after reflection therefrom, and (d) first extraneous sidewall illumination that has passed through the first sidewall beam splitter across the sidewall inspection area; redirecting each of the first reflected sidewall illumination, the second extraneous sidewall illumination, the second reflected sidewall illumination, and the first extraneous sidewall illumination toward an image capture device; capturing the first reflected sidewall illumination and the second extraneous sidewall illumination for the first area of the single image as a single image, and the second reflected sidewall illumination and the first extraneous sidewall illumination for the second area of the single image in a single image capture operation when the component is positioned in the sidewall inspection position; generating image data corresponding to the single image; and processing the image data to digitally filter pixel values corresponding to the second extraneous sidewall illumination from the first area of the single image and digitally filter the first extraneous sidewall illumination from the second area of the single image.

Simultaneously with or separately from the previous process, similar, effectively/essentially the same process operations may be performed for delivering third sidewall illumination and fourth sidewall illumination through a third sidewall beam splitter and a fourth sidewall beam splitter, the third sidewall beam splitter and the fourth sidewall beam splitter being disposed on opposite sides of the sidewall inspection region relative to different second axes, such that the third component sidewall and the fourth component sidewall disposed relative to each other along the second axis receive third incident sidewall illumination and fourth incident sidewall illumination, respectively; at the third sidewall beam splitter receiving (a) third reflected sidewall illumination that travels away from the third component sidewall after the third incident sidewall illumination impinges upon or is reflected from it, and (b) fourth external sidewall illumination that has been delivered through the fourth sidewall beam splitter across the sidewall inspection region; at the second sidewall beam splitter receiving (c) the fourth incident sidewall illumination after impinging upon and reflecting from it redirecting each of the third reflected sidewall illumination, the fourth extraneous sidewall illumination, the fourth reflected sidewall illumination, and the third extraneous sidewall illumination toward an image capture device; capturing in a single view the third reflected sidewall illumination and the fourth extraneous sidewall illumination for the third area as a single view, and the fourth reflected sidewall illumination and the third extraneous sidewall illumination for the fourth area as a single view when the component is positioned in the sidewall inspection position; generating image data corresponding to the single view; and processing the image data for the single view to digitally filter pixel values corresponding to the fourth extraneous sidewall illumination from the third area of the single view and to digitally filter the third extraneous sidewall illumination from the fourth area of the single view.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic diagram showing part of a conventional five-side inspection device.

FIG. 1B is a representative inspection image captured when the component is secured in a bottom surface inspection position corresponding to the inspection configuration shown in FIG. 1A .

1C is a schematic diagram illustrating a portion of the conventional five side inspection apparatus of FIG. 1A , wherein a component is held by a component holder at a sidewall inspection position.

FIG. 1D is a representative inspection image captured while the part is secured in the sidewall inspection position.

FIG. 1E provides a representative composite image produced by combining or digitally stitching together, respectively, the central and peripheral portions of the bottom surface inspection image and the sidewall inspection image.

FIG. 1F shows a portion of the composite image corresponding to a sidewall of a component.

2A-2C illustrate portions of an apparatus configured to perform five-sided component inspection and selected component sidewall inspection in addition to component bottom or bottom surface inspection, according to one embodiment of the present disclosure.

FIG. 2D illustrates a component positioned in a sidewall inspection position according to one embodiment of the present disclosure.

3 is a schematic diagram illustrating representative illumination travel paths corresponding to component bottom surface inspection concurrent with component side wall inspection with a bright field illuminator using the apparatus of FIGS. 2A-2C .

4A is a schematic diagram illustrating representative illumination travel paths corresponding to selected part sidewall inspection, in addition to part bottom surface inspection, through a set of sidewall illuminators using the apparatus of FIGS. 2A-2C .

4B is a representative multi-sidewall image showing four separate sidewall images corresponding to sidewall inspection operations occurring when a part is positioned in a sidewall inspection position, the brightfield illuminator is inactive, and the sidewall illuminator is active.

FIG4C is a representative individual sidewall image obtained from FIG4B .

5A is a diagram illustrating a representative first sidewall illuminator activation pattern according to one embodiment of the present disclosure.

5B is a representative first multi-sidewall image corresponding to the first side wall illuminator activation pattern of FIG. 5A captured when the part is positioned in the side wall inspection position, the first side wall illuminator and the third side wall illuminator are activated, and the second side wall illuminator and the fourth side wall illuminator are inactive.

5C is a diagram illustrating a representative second sidewall illuminator activation pattern according to one embodiment of the present disclosure.

5D is a representative second multi-sidewall image corresponding to the second side wall illuminator activation pattern of FIG. 5C captured when the part is positioned in the side wall inspection position, the second side wall illuminator and the fourth side wall illuminator are activated, and the first side wall illuminator and the third side wall illuminator are inactive.

FIG. 5E is a representative composite multi-sidewall image generated from the first multi-sidewall image of FIG. 5B and the second multi-sidewall image of FIG. 5D .

5F illustrates schematic top and side views of components of a representative first off-center sidewall inspection position disposed within a sidewall inspection region, according to one embodiment of the present disclosure.

5G illustrates schematic top and side views of the components of FIG. 5F disposed in a representative second off-center sidewall inspection position within the pen inspection area, according to an embodiment of the present disclosure.

6A is a schematic top view illustrating a portion of a wavelength separated sidewall inspection apparatus configured to perform the wavelength separated sidewall inspection technique according to one embodiment of the present disclosure.

6B is a schematic diagram of a representative wavelength-separated multi-sidewall image comprising four separate sidewall images captured simultaneously using four different optical wavelengths/bandwidths, according to one embodiment of the present disclosure.

6C is a diagram illustrating a first side wall illuminator activation pattern corresponding to a wavelength separated side wall inspection calibration procedure according to one embodiment of the present disclosure.

6D is a diagram illustrating a second side wall illuminator activation pattern corresponding to a wavelength-separated side wall inspection calibration procedure according to one embodiment of the present disclosure.

6E is a diagram illustrating a third side wall illuminator activation pattern corresponding to a wavelength-separated side wall inspection calibration procedure according to one embodiment of the present disclosure.

6F is a diagram illustrating a fourth side wall illuminator activation pattern corresponding to a wavelength-separated side wall inspection calibration procedure according to one embodiment of the present disclosure.

6G is a diagram illustrating a fifth side wall illuminator activation pattern corresponding to a wavelength separated side wall inspection calibration procedure according to one embodiment of the present disclosure.

6H is a diagram illustrating a sixth side wall illuminator activation pattern corresponding to a wavelength separated side wall inspection calibration procedure according to one embodiment of the present disclosure.

6I is a diagram illustrating a seventh side wall illuminator activation pattern corresponding to a wavelength-separated side wall inspection calibration procedure according to one embodiment of the present disclosure.

6J is a diagram illustrating an eighth side wall illuminator activation pattern corresponding to a wavelength separated side wall inspection calibration procedure according to one embodiment of the present disclosure.

6K is a schematic top view illustrating a portion of an optical wavelength or bandwidth separated sidewall inspection apparatus configured for performing an optical wavelength or bandwidth separated sidewall inspection process or technique according to one embodiment of the present disclosure.

7A-7C illustrate representative component inspection locations and corresponding representative captured images associated with a bottom surface only inspection location and a sidewall inspection location, according to one embodiment of the present disclosure.

7D is a representative composite five side inspection image including a central bottom surface image or image region and four peripheral sidewall images or image regions disposed around the central bottom surface image region, according to one embodiment of the present disclosure.

Specific embodiments

In this disclosure, the description of consideration or use of a given element or a specific number of elements in a specific figure or reference thereto in the corresponding descriptive material may encompass the same, equal or similar elements or identified numbers of elements in another figure or intended associated descriptive material. Unless otherwise indicated, the use of "/" in a figure or associated text is understood to mean "and/or". The expression of a specific numerical value or range of values herein is understood to include or be about a numerical value or range of values (e.g., within +/-20%, +/-15%, +/-10% or +/-5%). In addition, the use of "substantially perpendicular" or "generally perpendicular" may be understood to mean approximately perpendicular, for example, perpendicular within an angular range of +/-10 degrees or +/-5 degrees; and the use of "substantially parallel" or "generally parallel" may be understood to mean approximately parallel, for example, parallel within an angular range of +/-10 degrees or +/-5 degrees.

As used herein, the term "group" corresponds to or is defined as a non-empty finite organization of elements, which mathematically exhibits a cardinality of at least 1 (i.e., a group as defined herein may correspond to a unitary, simple, or single group of elements, or a plurality of groups of elements), according to known mathematical definitions (e.g., in a manner corresponding to that described in An Introduction to Mathematical Reasoning: Numbers, Sets, and Functions, "Chapter 11: Properties of Finite Combinations" (e.g., noted on page 140), Peter J. Eccles, Cambridge University Press (1998)). In general, an element of a group may include or be a value of a system, device, apparatus, structure, object, process, physical parameter, or group depending on the type of arrangement under consideration.

Embodiments according to the present disclosure relate to systems, devices, equipment, structures, processes and procedures for optical inspection, exposed, external or outer surfaces of components, including side surfaces extending between (a) a top or upper boundary, edge, or edge of a component or a point above it and (b) a bottom or lower boundary, edge or edge of a component or a point above it, and possible external component structures associated therewith. For simplicity and to aid understanding, the component side surfaces are referred to herein as "sidewalls". The components may include, for example, semiconductor devices, such as semiconductor dies or packaged integrated circuit (IC) chips, or other types of objects. Despite such nomenclature, it should be understood by a person of ordinary skill in the relevant art that, based on the description herein, embodiments according to the present disclosure may be applied to optical inspection of exposed, external or outer component side surfaces in (a) where such component side surfaces form one or more walls or wall-like structures, and (b) where such component side surfaces do not form one or more walls or wall-like structures. More specifically, while various embodiments according to the present disclosure may be applied to the optical inspection of regular or substantially regular multi-faceted parts (e.g., parts that appear to be rectangular or substantially rectangular in shape) having outer side surfaces that correspond to well-defined or easily identifiable vertical, angled and/or angled outer/external walls or faces according to various embodiments of the present disclosure, it may also be applied to the optical inspection of parts that appear to be other types of shapes (e.g., parts that appear to be elliptical or substantially elliptical in shape) for which vertical, angled or angled walls or faces are not necessarily well-defined.

Depending on the embodiment details, embodiments according to the present disclosure may be configured for inspecting component sidewalls and structures that may be associated therewith or protruding therefrom, separate/separate from or associated with inspecting one or more other component surfaces, such as a component top surface and/or a component bottom surface, and structures that may be associated therewith or protruding therefrom. Additionally, some embodiments are configured for selective or selectable inspection of certain component sidewalls at a given time, and inspection of other component sidewalls at another time. Certain embodiments are configured for inspection of multiple subsets of component sidewalls using multiple wavelengths or wavelength ranges of sidewall illumination simultaneously, for example, where a first subset of component sidewalls (e.g., a first pair of adjacent component sidewalls) is illuminated with sidewall illumination of a first wavelength or wavelength range of light, and another subset of component sidewalls (e.g., a second pair of adjacent component sidewalls) is simultaneously illuminated with sidewall illumination of a second, different wavelength or wavelength range of light. Inspection operations according to embodiments of the present disclosure may occur under program control, corresponding to the execution of a set of program instructions/software by a processing unit. Such software may reside in memory and/or on fixed or removable computer-readable storage media.

Figure 2A is a schematic side view of an apparatus 10 according to an embodiment of the present disclosure, wherein the apparatus 10 is configured to (a) capture corresponding to up to five component sides, including a component bottom/front surface and/or a component side surface/sidewall; (b) facilitate or perform component inspection of up to five sides; and (c) facilitate or perform component sidewall inspection in addition to component bottom or bottom surface inspection (e.g., on a selective basis). Figure 2B is a schematic side view of an apparatus 10 according to another embodiment of the present disclosure. Figure 2C is a top view of a portion of the apparatus of Figures 2A and 2B according to an embodiment of the present disclosure. Figures 2A and 2B define an apparatus x-axis and an apparatus z-axis, and Figure 2C defines an apparatus y-axis relative to the x-axis for reference purposes.

In one embodiment, the apparatus 10 includes a component holder, fixing structure or retaining element 50 for fixing or retaining the component 20 in one or more predetermined positions relative to each bright field illuminator 100; an image capture beam splitter 110 (e.g., such as shown in Figures 2A, 2B, 3 and 4A); a dark field illuminator 120; a set of side wall illuminators 200, which in this embodiment is shown to include an illumination setup, apparatus or device having four different or distinguishable side wall illumination output areas, or four different or distinguishable side wall illuminators 200a-d; a set of side wall beam splitters 210a-d; a lens assembly 300; and an image capture device 400 during a set or series of inspection operations. Figure 2D is a schematic perspective view of a portion of the device 10 of Figures 2A-2C, indicating that the device 10 may include a housing 12 that is configured to carry or support an image capture beam splitter 110, a set of side wall beam splitters 210a-d, a set of side wall illuminators 200a-d, a dark field illuminator 120, and a bright field illuminator 100, and at least some of a portion of the lens assembly 300.

In the representative embodiment shown, a set of side wall illuminators 200a-d includes first to fourth side wall illuminators 200a-d, and a set of side wall beam splitters correspondingly includes first to fourth side wall beam splitters 210a-d. Other embodiments may include fewer or additional side wall illuminators 200a-d and/or side wall beam splitters 210a-d, depending on the details of the embodiment, the type of component, and/or the component inspection requirements. In addition, although each embodiment of the apparatus for selectively inspecting components according to the present disclosure includes a set of side wall illuminators 200a-d and a corresponding set of side wall beam splitters 210a-d, certain embodiments may omit the bright field illuminator 100 and/or the dark field illuminator 120.

In various embodiments, a set of side wall illuminators 200 includes at least one illumination source. For example, each side wall illuminator 200a-d includes at least one illumination source, such as a set of LEDs (e.g., a set of one or more sets of white light LEDs, and/or a set of one or more sets of LEDs configured to output light at a specific optical center wavelength or optical bandwidth). Each side wall beam splitter 210a-d can be a conventional beam splitter, such as a cube-type beam splitter, a prism-type beam splitter, a plate-type beam splitter, or a mirror (e.g., a half-silvered mirror) that provides a beam splitting interface, surface, or face 212, such as a partially reflective/partially transmissive interface or surface, at or along which beam splitting occurs in a manner readily understood by one of ordinary skill in the relevant art. Thus, each side wall beam splitter 210a-d has an illumination delivery direction and an illumination reflection direction associated therewith, for example, perpendicular to the illumination delivery direction. Illumination incident upon the sidewall beam splitters 210a-d along an optical path parallel to the illumination delivery direction travels through the sidewall beam splitters 210a-d with substantially or essentially no reflection; and illumination incident upon the sidewall beam splitters 210a-d along an optical path opposite or opposite to the delivery direction is reflected by the sidewall beam splitters 210a-d in an illumination reflection direction (e.g., perpendicular, substantially perpendicular, or substantially perpendicular to the illumination delivery direction), in a manner readily understood by one of ordinary skill in the relevant art.

Similarly, the image capture beam splitter 110 can be a conventional beam splitter, such as a cube-type beam splitter, a prism-type beam splitter, a plate-type beam splitter, or a half-silvered mirror, which provides a beam splitting interface, surface, or face 112, such as a partially reflecting/partially transmitting interface or surface, at or along which the beam splitting occurs, as readily understood by one of ordinary skill in the relevant art. Thus, the image capture beam splitter 110 has an illumination transmission direction and an illumination reflection direction associated therewith, e.g., which is perpendicular to the illumination transmission direction. Illumination incident on the image capture beam splitter 110 along an optical path parallel to the illumination transmission direction travels through the image beam splitter 110 without substantial reflection; and illumination incident on the image capture beam splitter 110 along an optical path opposite or opposite to the illumination transmission direction is reflected by the image beam splitter 110 in the illumination reflection direction, as readily understood by one of ordinary skill in the relevant art.

The brightfield illuminator can be a conventional device configured to output brightfield illumination and can include one or more illumination sources, such as an array of LEDs (e.g., one or more groups of white light LEDs, and/or one or more groups of LEDs configured to output light at a specific central wavelength). The brightfield illuminator 100 can also be referred to as a brightfield coaxial illuminator, where "coaxial" is defined relative to the z-axis and indicates that the brightfield illuminator 100 is configured to output illumination in a direction that is primarily or essentially parallel to the z-axis. Correspondingly or equivalently, the brightfield illuminator 100 can be defined or referred to as a brightfield unidirectional illuminator 100, indicating that the brightfield illumination output by it propagates approximately, substantially, or essentially entirely in a single direction across a predetermined spatial distance, in a manner readily understood by one of ordinary skill in the relevant art. The darkfield illuminator can also be a conventional device configured to output high-angle darkfield illumination and/or low-angle darkfield illumination, such as a ring light comprising one or more rows or annular rings of LEDs.

The lens assembly 30 may include a conventional high-resolution lens (eg, a lens having a resolution of 2.0-4.0 microns), and the image capture device may be a conventional high-resolution digital camera (eg, a 25 megapixel camera).

In various embodiments, the component holder 50 includes or corresponds to a nozzle or tip of a pick and place device (e.g., a conventional pick and place device) that is configured to securely engage the first surface 22 of the component 20 (e.g., via suction) and transport or convey the component 20 to one or more inspection locations to facilitate inspection operations. For simplicity and to facilitate understanding, in the description herein, the component holder 50 is defined as engaging the component 20 on its upper or top surface 22 such that the component second, bottom or underside surface 24 is opposite and distal to the component top surface 22. Bright field illumination output by the bright field illuminator 100 travels toward the bottom surface 24 of the component 20 along a light travel path that is substantially or essentially perpendicular to the bottom surface 24 of the component 20. The component 20 includes a plurality of side surfaces or sidewalls 26, which in the representative embodiment are shown to include or equal to four sidewalls 26a-d, forming an outer perimeter of the component between the top surface 22 and the bottom surface 24 of the component. Component 20 can be essentially any type of object or device for which inspection of an image associated with or corresponding to its bottom surface 24 and/or some or all of its sidewalls 26a-d is desired or required. In the representative embodiment shown, component 20 is an IC chip having a plurality of solder bumps or balls 28 on bottom surface 24. One of ordinary skill in the relevant art will recognize that the manner in which component holder 50 engages component 20 or a given component surface can be altered or varied, and/or the definitions of top/upper and bottom/lower side surfaces 22, 24 can be reversed, depending on the embodiment and/or contextual details. Such component engagement and component surface definitions are used herein for purposes of example and to aid understanding.

In general, the component holder 50 can securely engage (e.g., releasably) with the top surface 22 of a given component, pick up the component 20, transport the component toward/to the apparatus 10, vertically position the component 20 along the z-axis at one or more predetermined inspection locations relative to the apparatus 10, and laterally position the component 20 at one or more x-y plane locations within the sidewall inspection space, region, volume, or area 30 between the sidewall beam splitters 210a-d so that (a) illumination can be directed to a particular component surface using one or more of the brightfield illuminator 100, the darkfield illuminator 120, and the set of sidewall illuminators 200a-d, and (b) one or more images associated with or corresponding to the component bottom surface 24 and/or the component sidewalls 26a-d can be captured by (i) reflection of illumination from such component surfaces 24, 26a-d and (ii) the direction (redirection) of such reflected illumination toward or into the lens assembly 300 and to the image capture device 400.

In various embodiments, the component holder 50 can position the component 20 being transported thereby at one or more sidewall inspection locations within the sidewall inspection area 30, where the component 20 is disposed between a set of sidewall beam splitters 210a-d and the sidewalls 26a-b of the component are bounded, surrounded, or enclosed by the set of sidewall beam splitters 210a-d. For example, the component holder 50 can position the component 20 at a central or center sidewall inspection location such that the midpoint, centroid, or center point of the component 20 resides approximately midway between the set of sidewall beam splitters 210a-d. For example, although the component 20 is positioned in a central sidewall inspection position, the sidewalls 26a, 26b, 26c, 26d of the component opposite or facing the opposite sidewall beam splitters 210a, 210b, 210c, 210d may be approximately equidistant from the corresponding opposite sidewall beam splitters 210a, 210b, 210c, 210d; or each component sidewall 26a-d may be approximately equidistant from the corresponding sidewall beam splitters 210a-d (for example, depending on the arrangement of the sidewall beam splitters 210a-d, and the shape of the sidewall inspection area 30).

Additionally or alternatively, in some embodiments, the component holder 50 may position the component 20 in an off-center sidewall inspection position such that component sidewalls 26a, c–26b, d/26a, d–26b, c (e.g., adjacent component sidewalls 26a, c–26b, d/26a, d–26b, c) that share a common border or edge are disposed equidistant from corresponding sidewall beam splitters 210a, c–210b, d/210a, d–210b, c (e.g., adjacent sidewall beam splitters 210a, c–210b, d/210a, d–210b, c) and the component midpoint, centroid, or center point is oriented toward the corresponding selected/selectable sidewall beam splitters 210a, c–210b, d/210a, d–210b, c (e.g., a given pair of adjacent sidewall beam splitters 210a, c–210b). 0a, c–210b, d/210a, d–210b, c) is offset away from the midpoint between any two opposing or oppositely disposed sidewall beam splitters 210a, c–210b, d/210a, d–210b, c, whereby a particular subset of component sidewalls sharing a common boundary or edge 26a, c–26b, d/26a, d–26b, c (e.g., a particular pair of adjacent component sidewalls 26a, c–26b, d/26a, d–26b, c) is disposed closer to its corresponding adjacent or adjacent sidewall beam splitters 210a, d–210b, c/210a, c–210b, d than another subset of adjacent or adjacent sidewall beam splitters 210a, d–210b, d/210a, d–210b, c. In this case, the side wall illuminators 200a, c–200b, d/200a, d–200b, c corresponding to adjacent side wall beam splitters 210a, c–210b, d/210a, d–210b, c can be selectively activated and, during a single image capture operation, images of the corresponding component side walls 26a, c–26b, d/26a, d–26b, c under consideration that share a common boundary or edge (e.g., adjacent component side walls 26a, c–26b, d/26a, d–26b, c) relative to the adjacent side wall beam splitters 210a, c–210b, d/210a, d–210b, c can be captured, for example, as a single image. The process can be repeated by moving or transferring the component 20 to another off-center sidewall inspection position relative to or within the inspection area 30, for example, in a diagonal direction away from a corner area of the currently occupied sidewall inspection area 30 to a corner area of the currently unoccupied sidewall inspection area 30, so that another pair of adjacent component sidewalls 26b, d–26a, c/26b, c–26a, d are arranged to be equidistant from corresponding adjacent or adjacent sidewall beam splitters 210b, d–210a, c/210b, c–210a, d, and during a single image capture operation, the corresponding sidewall illuminators 200b, d–200a, c/200b, c–200a, d can be selectively activated and an image of the adjacent component sidewall 26b, d–26a, c/26b, c–26a, d on which the current sidewall illumination is incident can be captured, for example, as a single image. This is further explained in detail below with reference to the representative embodiments shown in Figures 5F and 5G.

Typically, when component 20 is positioned or secured in the sidewall inspection position, sidewall beam splitters 210a-d are positioned around a portion of the component's perimeter defined by the surface area occupied by the component's sidewalls 26a-d such that the vertical extent of each component sidewall 26a-d is within the vertical extent of the corresponding sidewall beam splitter 210a-d. As a result, when component 20 is positioned in the sidewall inspection position, component 20 will act as a barrier to at least some light propagation between pairs of opposed sidewall beam splitters 210a-d, between which light may propagate directly without component 20.

FIG2E is a schematic diagram illustrating a representative positioning of component 20 in a sidewall inspection position (e.g., a central sidewall inspection position) according to an embodiment of the present disclosure. More specifically, as indicated in FIG2E , when component 20 is positioned in this representative sidewall inspection position, first component sidewall 26a is positioned proximate to or adjacent to/near first sidewall beam splitter 210a such that first component sidewall 26a can receive illumination from first sidewall beam splitter 210a at an incident angle of approximately 90 degrees. More specifically, first sidewall 26a is disposed (a) perpendicular or substantially perpendicular to a first axis, such as the aforementioned x-axis, which corresponds to or is parallel to the first illumination propagation axis/optical axis and the illumination delivery direction of first sidewall beam splitter 210a; and (b) parallel or substantially parallel to a second axis, such as the perpendicular or z-axis, which corresponds to or is parallel to the first illumination propagation axis/optical axis and the illumination reflection direction of first sidewall beam splitter 210a.

2E , similar considerations apply with respect to the second through fourth sidewalls 26 b-d of the component. Thus, when the component 20 is positioned in the sidewall inspection position, each of the first and second sidewalls 26 a-b of the component is positioned (a) perpendicular or substantially perpendicular to the aforementioned x-axis, which corresponds to or is parallel to the first illumination propagation axis/optical axis and the illumination delivery direction of each of the first sidewall beam splitter 210 a and the second sidewall beam splitter 210 b; and (b) parallel or substantially parallel to the aforementioned z-axis, which corresponds to or is parallel to the second illumination propagation axis/optical axis and the illumination reflection direction of each of the first sidewall beam splitter 210 a and the second sidewall beam splitter 210 b. In addition, each of the third and fourth side walls 26c-c of the component is configured to be (a) perpendicular or substantially perpendicular to the aforementioned y-axis, which corresponds to or is parallel to the first illumination propagation axis/optical axis and the illumination delivery direction of each of the third side wall beam splitter and the fourth side wall beam splitter 210c-d; and (b) parallel or substantially parallel to the aforementioned z-axis, which corresponds to or is parallel to the second illumination propagation axis/optical axis and the illumination reflection direction of each of the third side wall beam splitter and the fourth side wall beam splitter 210c-d.

While the component 20 is positioned in this sidewall inspection position, the component 20 can block illumination traveling along at least some optical paths parallel to or substantially parallel to the x-axis or y-axis between the sidewall beam splitters 210a, b, 210c, d, which are positioned relative to each other along the x-axis or y-axis, respectively. Thus, the sidewalls 26a-d of the component can be selectively/optionally illuminated by light incident thereon as a result of (a) brightfield illumination output by the brightfield illuminator 100 and reflected by the set of sidewall beam splitters 210a-d toward the component sidewalls 26a-d; (b) darkfield illumination output by the darkfield illuminator 120 toward the component sidewalls 260a-d, some of which will be directly incident on the component sidewalls 26a-d and some of which is reflected by the sidewall beam splitters 210a-d; and/or (c) sidewall illumination output by the set of sidewall illuminators 210 that has traveled along a direct optical path through the set of sidewall beam splitters 210a-d toward the component sidewalls 26a-c. When one or more images including component sidewalls 26 a - d are captured and subsequently processed/analyzed (e.g., by image processing operations), the likelihood of detecting specific types of defects, particularly very small micro-defects, present in or on component sidewalls 26 a - d depends on which one or more of these illuminators are used, as described in further detail below.

In various embodiments, for each component sidewall 26a-d under consideration (e.g., each component sidewall 26a-d upon which sidewall illumination is incident), the reflected sidewall illumination travels an equal distance between the component sidewalls 26a-d and the image capture plane of the image capture device 400. Thus, when the component 20 is positioned in the sidewall inspection position within the sidewall inspection area 30, the captured image of the component sidewalls 26a-d is in focus relative to the image capture plane. Certain embodiments may include a plurality of optical elements disposed along the optical path between portions of the component 20 (e.g., component sidewalls 26a-d) and the image capture device 400 to compensate for differences in optical path length between illumination reflected from the component bottom surface 24 and sidewall illumination reflected from the component sidewalls 26a-d relative to the image capture plane of the image capture device 400. For example, referring to Figures 2B, 2C and 2E, when the component 20 is centrally aligned relative to the sidewall beam splitters 210a-d so that the component 20 is positioned at a central sidewall inspection position within the sidewall inspection area 30, the sidewall beam splitters 210a-d are configured as prisms having appropriate refractive indices, and/or are separated from the sidewall beam splitters 210a-d, and the sidewall beam splitters 210a-d providing a set of prisms having appropriate refractive indices can be used to compensate for optical path length differences so that the bottom image surface 410 associated with or corresponding to the bottom surface 24 of the component is in focus relative to the image capture plane within the image capture device 400; and the first sidewall image plane 420a associated with or corresponding to the first sidewall 26a of the component is in focus relative to the image capture plane within the image capture device 400. Accordingly, in this embodiment, each of the bottom image plane 410, the second sidewall image plane corresponding to the second sidewall 26b of the component, the third sidewall image plane corresponding to the third sidewall 26c of the component, and the fourth sidewall image plane corresponding to the fourth sidewall 26d of the component can be in focus relative to the image capture plane within the image capture device 400.

The image capture device 400 provides a sufficiently large field of view (FOV) to capture portions of the bottom image plane 410 and/or portions of one or more sidewall image planes 420 via (a) separate image capture operations as separate images, or (b) a single image capture operation as a single image that includes pixels corresponding to imaged details of the part bottom surface 24 and/or imaged details corresponding to a given subset of or each of the part sidewalls 26 a-d, depending on embodiment details, the part inspection method under consideration (e.g., as defined by a set of program instructions executable by the processing unit), and/or the sidewall illuminator activation mode under consideration.

FIG3 is a schematic diagram illustrating component 20 illuminated by brightfield illumination output by brightfield illuminator 100, according to an embodiment of the present disclosure, with sidewall illuminators 200a-d turned off when component 20 is positioned in a central sidewall inspection position. In one embodiment, the brightfield illumination emitted or output by brightfield illuminator 100 includes illumination that travels along an optical path through image capture beam splitter 100 in an upward direction parallel or substantially/generally parallel to the z-axis. Some of this brightfield illumination travels directly onto component bottom surface 24 and solder balls 28 disposed thereon. Brightfield illumination incident perpendicularly or approximately perpendicularly upon component bottom surface 24 and solder balls 28 is reflected by them in a downward direction parallel or substantially/generally parallel to the z-axis toward and onto partially reflecting/partially transmitting surface 112 of image capture beam splitter, which then reflects or redirects some of this reflected downside illumination in a direction parallel, substantially parallel, or substantially parallel to the x-axis toward and into lens assembly 300.

Some of the brightfield illumination output by the brightfield illuminator 100 also travels upward along an optical path in a direction parallel, substantially parallel, or generally parallel to the z-axis to the sidewall beam splitters 210a-d, which reflect or redirect the brightfield illumination so that it travels along a lateral optical path that is parallel or substantially parallel to the x-axis or y-axis and perpendicular or substantially perpendicular to the sidewalls 20a-d of the component. A portion of this lateral illumination will be incident perpendicularly or substantially perpendicularly on the component sidewalls 26a-d and reflected back by the sidewall beam splitters 210a-d. The sidewall beam splitters 210a-d redirect the illumination received from the component sidewalls 26a-d in a downward direction toward the imaging beam splitter 110, and the imaging beam splitter reflective surface 112 redirects the illumination toward and into the lens assembly 300 and image capture device 400.

Some of the aforementioned laterally traveling illumination that is reflected by the sidewall beam splitters 210a-d will not be incident on the component sidewalls 26a-d or structures associated therewith (e.g., leads), and will simply travel through the component 20 to the opposing sidewall beam splitter 210a-b and be redirected toward the imaging beam splitter, whereupon this extraneous bright field illumination is redirected toward and into the lens assembly 300 and image capture device.

Thus, under brightfield lighting conditions, if this mode of operation is desired or selected, the device 100 can function as a conventional five-sided inspection device. Similar or substantially similar considerations apply to darkfield lighting conditions and the generation of extraneous darkfield illumination, in a manner readily understood by those of ordinary skill in the relevant art.

Representative sidewall lighting and inspection configurations/operations

As described in further detail below, during the inspection process, various embodiments of the present disclosure can selectively disable, deactivate, or turn off the brightfield illuminator and activate or turn on some or each of the sidewall illuminators 200a-d so that extraneous brightfield illumination or its effect on the sidewall inspection is compensated for, or reduced, substantially eliminated, eliminated, or effectively/essentially eliminated from the captured sidewall image. Similar considerations apply to turning off the darkfield illuminator 120, with some or each of the sidewall illuminators 200a-d remaining activated so that extraneous darkfield illumination or its effect on the sidewall inspection can be reduced, substantially eliminated, eliminated, or effectively/essentially eliminated from the captured sidewall image. Furthermore, during the sidewall inspection process, various embodiments according to the present disclosure may deactivate the brightfield illuminator 100 and the darkfield illuminator 120 while selectively activating specific adjacent sidewall illuminators 200a, c, 200b, d (or 200a, d, 200b, c) while the other sidewall illuminators remain inactive or off, thereby reducing, eliminating, or effectively/essentially eliminating (a) extraneous sidewall illumination caused by the transfer of sidewall illumination output by a group of sidewall illuminators 200a-d through oppositely disposed sidewall beam splitters 210a, b, 210c, d and across the sidewall inspection area 30 without reflection from the component sidewalls 26a, b, 26c, d; and/or (b) the effect of such extraneous sidewall illumination on the sidewall inspection. During a component sidewall inspection procedure (e.g., during which the brightfield illuminator 100 and the darkfield illuminator 120 remain off), extraneous sidewall illumination caused by the sidewall illumination output by the sidewall illuminators 200a-d can be categorized or defined as non-brightfield extraneous illumination and non-darkfield extraneous illumination. In various embodiments, extraneous sidewall illumination or its effect on sidewall inspection can be compensated for, or reduced, substantially eliminated, eliminated, or effectively/essentially eliminated, by activating specific sidewall illuminators 200a-d or each sidewall illuminator 200a-d in a manner that is separate in wavelength or bandwidth relative to other sidewall illuminators 200a-d and/or by filtering light based on the wavelength or bandwidth associated with the oppositely disposed sidewall illuminators 200a,b, 200c,d. Such sidewall illumination and inspection configurations and techniques may improve or greatly improve the contrast and clarity of pixels within captured and/or composite images corresponding to the sidewalls of a component, thereby improving or greatly improving the likelihood of detecting sidewall micro-defects (e.g., defects having a size of approximately 5 μm or less) and improving or greatly improving sidewall inspection accuracy.

4A is a schematic diagram illustrating component sidewalls 26a-d illuminated by sidewall illumination output from a set of sidewall illuminators 200, while the brightfield illuminator 100 and the darkfield illuminator 120 are turned off, in accordance with an embodiment of the present disclosure. In an embodiment, when the sidewall illuminators 200a-d are turned on, the sidewall illumination output thereby travels along an optical path parallel to/substantially parallel to the x-axis or y-axis (depending on which sidewall illuminator 200a-d and sidewall beam splitter 210a-d are in question) toward the component sidewalls 26a-d and through the corresponding sidewall beam splitters 210a-d, and perpendicular to/substantially perpendicular to the component sidewalls 26a-d and each corresponding sidewall imaging plane 420a-d.

A portion of the sidewall illumination that passes through the sidewall beam splitters 210a-d will be incident upon the component sidewalls 26a-d and reflected back toward the sidewall beam splitters 210a-d. The sidewall beam splitters 210a-d redirect the reflected sidewall illumination toward the image capture beam splitter 110, whereupon the reflected sidewall illumination is further redirected toward and into the lens assembly 300 and image capture device 400, thereby facilitating the capture of images of the component sidewalls 26a-d.

Some of the sidewall illumination emitted by the sidewall illuminators 200a-d that passes through the sidewall beam splitters 210a-d will not be incident on the component sidewalls 26a-d, but instead will travel to the opposite sidewall beam splitter 210a-d, whereupon the sidewall illumination will be redirected toward the image capture beam splitter 110, whereupon the sidewall illumination is further redirected toward and into the lens assembly 300 and image capture device 400. For example, when the first sidewall beam splitter 210a receives the first sidewall illumination provided by the first sidewall illuminator 200a, a portion of the first sidewall illumination transmitted through the first sidewall beam splitter 210a will be incident on the first component sidewall 26a and reflected thereby, while another portion of the first sidewall illumination transmitted through the first sidewall beam splitter 210a that is not incident on and reflected (or blocked) by the first component sidewall 26a will travel from the first sidewall beam splitter 210a through the component 20 to the second sidewall beam splitter 210b, which is on the opposite side of the sidewall inspection area 30. The first sidewall illumination that has not been reflected (or blocked) by the first component sidewall 26a and that travels to the second sidewall beam splitter 210b may be received and redirected by the second sidewall beam splitter 210b as extraneous first sidewall illumination. Some of the extraneous first sidewall illumination may illuminate the component sidewall 26b, thereby causing "crosstalk" in the image of the component sidewall 26b. Similarly, when the second sidewall beam splitter 210b receives the second sidewall illumination provided by the second sidewall illuminator 200b, a portion of the second sidewall illumination transmitted through the second sidewall beam splitter 210b will be incident on the second component sidewall 26b and reflected by the second component sidewall 26b, while another portion of the second sidewall illumination transmitted through the second sidewall beam splitter 210b that is not incident on and reflected (or blocked) by the second component sidewall 26b will instead travel from the second sidewall beam splitter 210b through the component 20 to the first sidewall beam splitter 210a, which is on the opposite side of the sidewall inspection area 30. The second sidewall illumination that is not reflected (or blocked) by the second component sidewall 26b may be received and redirected by the first sidewall beam splitter 210a as extraneous second sidewall illumination. Some of this extraneous second sidewall illumination may illuminate the component sidewall 26a, thereby causing "crosstalk" in the image of the component sidewall 26a. Similarly, when third sidewall beam splitter 210c receives tertiary sidewall illumination provided by third sidewall illuminator 200c, a portion of the tertiary sidewall illumination transmitted through third sidewall beam splitter 210c will be incident on and reflected by third component sidewall 26c, while another portion of the tertiary sidewall illumination transmitted through third sidewall beam splitter 210c that is not incident on and reflected by third component sidewall 26c will instead travel from third sidewall beam splitter 210c through component 20 to fourth sidewall beam splitter 210d, which is on the opposite side of sidewall inspection area 30. Tertiary sidewall illumination that has not been reflected by third component sidewall 26c and instead travels to fourth sidewall beam splitter 210d may be received and redirected by fourth sidewall beam splitter 210d as extraneous tertiary sidewall illumination. Correspondingly, when fourth sidewall beam splitter 210d receives fourth sidewall illumination provided by fourth sidewall illuminator 200d, a portion of the fourth sidewall illumination transmitted through fourth sidewall beam splitter 210d will be incident on fourth component sidewall 26d and reflected by fourth component sidewall 26d, while another portion of the fourth sidewall illumination transmitted through fourth sidewall beam splitter 210d that is not reflected by fourth component sidewall 26d will instead travel from fourth sidewall beam splitter 210d through component 20 to third sidewall beam splitter 210c, which is on the opposite side of sidewall inspection area 30. Fourth sidewall illumination that has not been reflected by fourth component sidewall 26d and instead travels to fourth sidewall beam splitter 210d can be received and redirected by third sidewall beam splitter 210c as extraneous fourth sidewall illumination. Such illumination output by the sidewall illuminator that is not reflected by any of the component sidewalls 26a-d or component structures associated therewith is extraneous sidewall illumination, which is a type of optical crosstalk. According to various embodiments of the present disclosure, the reduction, elimination, or effective elimination of extraneous sidewall illumination and corresponding "optical crosstalk" or effects associated therewith relative to an inspection process performed on a captured image that includes a component sidewall or a sidewall image region therein results in a significantly or greatly improved ability to detect micro-defects in sidewall images that is not possible when conventional extraneous illumination (e.g., extraneous brightfield illumination and/or extraneous darkfield illumination) is present, or when extraneous sidewall illumination is present, or when compensation for the presence of extraneous sidewall illumination does not occur/is performed. In various embodiments, reduction, elimination, or effective elimination of extraneous sidewall illumination or its effects on sidewall inspection is achieved by (a) selective activation of particular sidewall illuminators 200a-d at particular times such that sidewall illumination of the same or overlapping wavelengths or bandwidths of light is prevented from being simultaneously transmitted through opposing sidewall beam splitters 210a, b, 210c, d; and/or (b) providing or generating sidewall illumination of separated wavelengths or bandwidths of light and/or sidewall illumination corresponding to reflections of opposing sidewall beam splitters 210a, b, 210c, d, as further described below.

4B is a representative multi-sidewall image showing four separate sidewall images corresponding to a sidewall inspection operation occurring when the part 20 is positioned in a sidewall inspection position centered within the sidewall inspection area 30, and the field illuminator 100 and the darkfield illuminator 120 are inactive or off, and at specific/different times, specific sidewall illuminators 200a-d (e.g., one of a pair of opposing sidewall illuminators 210a, b, 210c, d) are activated, or each of the sidewall illuminators 200a-d are activated simultaneously (e.g., separated by optical wavelength or optical bandwidth), as further detailed below.

One of ordinary skill in the relevant art will recognize that multiple sidewall images such as that shown in FIG. 4B may also be produced when (a) opposing sidewall illuminators 200a, b, 200c, d simultaneously output sidewall illumination at the same or overlapping wavelength or wavelength range of light, and (b) one or more sets of anti-reflective coatings and/or light polarization techniques and/or polarization elements/structures (e.g., polarizing filters) are positioned relative to an optical path along which sidewall illumination may be transmitted (i) through a given sidewall beam splitter 210a, c, 210b, d, (ii) across the sidewall inspection region 30, and (iii) to an opposing sidewall beam splitter 210b, c, 210a, c, thereby reducing, minimizing, or effectively eliminating optical crosstalk caused by extraneous sidewall illumination and/or its impact on the sidewall inspection operation. For example, in one embodiment, it is possible to have each of the wall illuminators 200a-d emit light of the same wavelength to illuminate the corresponding component sidewalls 26a-d passing through the corresponding sidewall beam splitters 210a-d. However, each of the opposing pairs of sidewall beam splitters (e.g., 210b & c) would have to be mounted with a polarizer (e.g., a wire grid polarizer) set at a different polarization angle so that light of a particular polarization passing through one of the sidewall beam splitters 210b (unblocked by the corresponding component sidewall 26a) and crossing over to the opposing sidewall beam splitter 210c would be absorbed or reflected off the opposing component sidewall 26c by the other polarizer coupled into the opposing sidewall beam splitter 210c, and vice versa. In this way, extraneous light (crosstalk) from opposing sidewall illuminators 200a-d can be eliminated so that only light of a specific polarization passing through one of the sidewall beam splitters 210a-d will be reflected off the corresponding component sidewall 26a-d, while its extraneous components are absorbed by the polarizers in the opposing sidewall beam splitters. This approach is particularly useful if broadband illumination (mixed oscillation) is desired for the illuminators. With a specific polarizer delivered from the polarizing beam splitters 210a-d to the corresponding component sidewall, using a black and white camera not only eliminates optical crosstalk but also allows for the capture of clearer and sharper images of ultrafine defects.

FIG4C is a representative, separate sidewall image obtained from FIG4B . A comparison between FIG4B and FIG1F clearly indicates that fine, ultrafine, or microscale features in the sidewall image corresponding to actual sidewall structural features, shadows, and/or defects are more clearly defined in FIG4B than in FIG1B . Thus, embodiments according to the present disclosure can greatly enhance the detection of fine, ultrafine, or microscale (less than or equal to approximately 5 μm) defects in captured sidewall images, and correspondingly greatly improve the accuracy of image processing-based sidewall inspection.

In some embodiments, multiple sidewall images, such as that shown in FIG4B , can be captured as a single view in a single image capture operation by deactivating/turning off the brightfield illuminator 100 while each of the sidewall illuminators 200 a-d is simultaneously turned on with appropriate wavelengths or bandwidths of light separated when the part 20 is positioned at or substantially at the central sidewall inspection position and the images captured, as described in further detail below. Alternatively, such multiple sidewall images can be generated as a composite image from multiple captured images generated by different or separate image capture operations when the part 20 is positioned at the central sidewall inspection position. Each image from which the composite image is generated corresponds to a specific subset of the activated sidewall illuminators 200 a-d that were activated at a specific time during a given image capture operation, and each such image from which the composite image is generated includes image data (e.g., pixel values) associated with a corresponding subset of a specific part sidewall 26 a-d. For example, individual sidewall images corresponding to each component sidewall 26a-d (or each component sidewall 26a-d of interest) may be captured individually/separately/sequentially using sidewall illuminators 200a-d configured to output sidewall illumination of the same or overlapping wavelengths or bandwidths of light. Alternatively, multiple sidewall images corresponding to non-opposing pairs of component sidewalls 26a,c-26b,d/26a,d-26b,c excluding sidewall images of opposing component sidewalls 26a,b,26c,d may be captured separately/sequentially/sequentially using (a) incident sidewall illumination of the same wavelength or bandwidth of light (associated with an image capture device 400 having a monochrome or color image sensor), or (b) incident sidewall illumination of different wavelengths or bandwidths of light (associated with an image capture device 400 having a color image sensor), as described in more detail below.

Representative selective activation of sidewall illuminators

In several embodiments, the sidewall illuminators 200a-d can be turned on or activated individually or in specific subsets (e.g., in pairs, to avoid simultaneous delivery of sidewall illumination through opposing sidewall beam splitters 210a, b, 210c, d) in a manner that further reduces, eliminates, or effectively eliminates extraneous sidewall illumination in captured sidewall images or its impact on sidewall inspection based on the captured sidewall images, thereby further improving sidewall inspection accuracy. Such selective activation of the sidewall illuminators 200a-d can include selective delivery of monochromatic or substantially monochromatic sidewall illumination or colored sidewall illumination through specific sidewall beam splitters 210a-d or onto corresponding specific component sidewalls 26a-d. As will be appreciated by those skilled in the relevant art, monochromatic illumination can be captured by a monochromatic image sensor or a color image sensor; and colored illumination can be captured by a color image sensor so that different wavelengths of light corresponding to different color pixel data values or corresponding to a range of color pixel values within the image data of the captured image can be easily distinguished and/or processed separately, thereby facilitating sidewall inspection operations.

For example, FIG5A is a schematic diagram of a representative first side wall illuminator activation pattern, wherein the first side wall illuminator 200a and the adjacent third side wall illuminator 200c are activated or turned on; and the second side wall illuminator 200b opposite the first side wall illuminator 200a and the fourth side wall illuminator 200d opposite the third side wall illuminator 200c remain inactive or turned off. Due to this side wall illuminator activation pattern, the captured side wall image corresponding to the first component side wall 26a will not include or be affected by the extraneous side wall lighting associated with the second side wall illuminator 200b; and the captured side wall image corresponding to the third component side wall 26c will not include or be affected by the extraneous side wall lighting associated with the fourth side wall illuminator 200d.

When pairs of oppositely disposed sidewall illuminators 200a-b, 200c-d are activated such that only one sidewall illuminator 200a-b, 200c-d within each pair of oppositely disposed sidewall illuminators 200a-b, 200c-d outputs illumination during a given image capture operation, extraneous sidewall illumination that would otherwise be associated with the currently inactive sidewall illuminators 200a-b, 200c-d is not generated and, therefore, is not captured as part of the sidewall image. This can further significantly improve the clarity of part sidewall features, shadows, and/or defects, and further increase the accuracy of part sidewall inspection.

FIG5B is a representative first multi-sidewall image corresponding to the first sidewall illuminator activation pattern of FIG5A , captured when part 20 is positioned in the center sidewall inspection position, the first and third sidewall illuminators 200 a, c are activated, and the second and fourth sidewall illuminators 200 b, c are inactive. As indicated in FIG5B , the first multi-sidewall image includes a left image region in which pixels clearly represent or contain useful information corresponding to first part sidewall 26 a, and an upper image region in which pixels clearly represent or contain useful information corresponding to third part sidewall 26 c. The first multi-sidewall image does not include image regions having pixels clearly representing or containing pixels corresponding to second or fourth sidewalls 26 b, d because the corresponding sidewall illuminators 200 b, d were deactivated during the image capture operation. That is, because the first and third side wall illuminators 200a, c are active during the image capture operation and the second and fourth side wall illuminators 200b, d are inactive during the image capture operation, the resulting captured image includes detailed side wall images or side wall image areas corresponding to the first and third component side walls 26a, c, but excludes detailed side wall images or side wall image areas corresponding to the second and fourth component side walls 26b, d.

Similarly, FIG5C illustrates a representative second side wall illuminator activation pattern, wherein the second side wall illuminator 200b and its adjacent fourth side wall illuminator 200d are activated or turned on; and the second side wall illuminator 200a and the third side wall illuminator 200c remain inactive or turned off. Thus, the captured side wall image corresponding to the second component side wall 26b will not include or be affected by the extraneous side wall lighting associated with the first side wall illuminator 200a; and the captured side wall image corresponding to the fourth component side wall 26d will not include or be affected by the extraneous side wall lighting associated with the third side wall illuminator 200c.

FIG5D is a representative second multi-wall image corresponding to the second sidewall illuminator activation pattern of FIG5C , captured when part 20 is positioned in the center sidewall inspection position, the second and fourth sidewall illuminators 200 b, d are activated, and the first and third sidewall illuminators 200 a, c are inactive. As indicated in FIG5D , the second multi-wall image includes a right image region in which pixels clearly represent or contain useful information corresponding to second part sidewall 26 b, and a lower image region in which pixels clearly represent or contain useful information corresponding to fourth part sidewall 26 d. The second multi-wall image does not include image regions having pixels clearly representing or containing pixels corresponding to first or third sidewalls 26 a, c because the corresponding sidewall illuminators 200 a, c were deactivated during the image capture operation. That is, because the second and fourth side wall illuminators 200b, d are active during the image capture operation and the first and third side wall illuminators 200a, c are inactive during the image capture operation, the resulting captured image includes detailed side wall images or side wall image areas corresponding to the second and fourth component side walls 26b, d, but excludes detailed side wall images or side wall image areas corresponding to the first and third component side walls 26a, c.

For sidewall inspection (e.g., automated sidewall defect inspection), some embodiments perform separate image processing operations on: (a) separate sidewall images, or (b) multiple sidewall images that include image regions having pixels that clearly represent or contain useful information corresponding to only a specific subset of component sidewalls 26 a-d (e.g., automated sidewall defect inspection may be performed on two separate multiple sidewall images, each multiple sidewall image including image regions having pixels that clearly represent or contain useful information corresponding to a specific adjacent pair of component sidewalls 26 a,c-26 b,d/26 a,d-26 b,c). However, particular embodiments may additionally or alternatively generate a single composite multiple sidewall image that includes image regions having pixels that clearly represent or contain useful information corresponding to each component sidewall 26 a-d (or each component sidewall 26 a-d of interest within a plurality of component sidewalls 26 a-d, which may include opposing component sidewalls 26 a,b, 26 c,d), and perform image processing operations on the single composite image.

A representative single composite multi-sidewall image can be generated by digitally stitching together those portions of the aforementioned first multi-sidewall image that contain detailed sidewall images or sidewall image areas corresponding to a first subset of component sidewalls 26a-d with those portions of the aforementioned second multi-sidewall image that contain detailed sidewall images or image areas corresponding to a second subset of component sidewalls 26a-d, while excluding composite image portions of each of the first multi-sidewall image and the second multi-sidewall image that do not contain detailed sidewall images or sidewall image areas. More specifically, a single composite multi-sidewall image can be generated from the first and second multi-sidewall images by digitally combining or stitching together a left image area of the first multi-sidewall image, an upper image area of the first multi-sidewall image, a right image area of the second multi-sidewall image, and a lower image area of the second multi-sidewall image. In some embodiments, if desired or necessary, a central area of the composite multi-sidewall image can be filled with a predetermined pixel value (e.g., corresponding to black). FIG. 5E is a representative composite multi-sidewall image generated from the first multi-sidewall image of FIG. 5B and the second multi-sidewall image of FIG. 5D .

As previously noted, in addition to the foregoing, in several embodiments, the component holder 50 selectively positions the component 20 being transported thereby at one or more lateral or x-y plane positions other than the central sidewall inspection position within the sidewall inspection area 30, such that the component 20 is closer to certain sidewall beam splitters 210a-d than to other sidewall beam splitters 210a-d. Thus, the component holder 50 selectively positions the component 20 "off-center" between two or more sidewall beam splitters 210a-d such that the component 20 is positioned toward a particular edge, side surface, or corner within the sidewall inspection area 30, and thus is positioned or biased toward a particular edge, side, or corner corresponding to or formed by certain sidewall beam splitters 210a-d, and away from another edge, side, or corner corresponding to or formed by one or more other sidewall beam splitters 210a-d. For example, the component holder 50 may position the component 20 so that the centroid or center point of the component (e.g., defined as the center point within the body of the component 20, or the center point on the bottom and/or top surfaces 22, 24 of the component) is positioned toward or closer to a particular (e.g., first) subset of sidewall beam splitters 210a, c that share a first corresponding or common boundary or edge (e.g., due to their proximity) than another (e.g., second) subset of sidewall beam splitters 210a, d that share a second corresponding or common boundary or edge (e.g., due to their proximity).

5F illustrates schematic top and side views of component 20 positioned at a representative first off-center sidewall inspection position within sidewall inspection area 30 such that component center point 21 is closer to a first subset of non-opposed sidewall beam splitters 210a-d, such as the first and third sidewall beam splitters 210a,c, than to a second subset of non-opposed sidewall beam splitters 210a-d, such as the second and fourth sidewall beam splitters 210b,d. Similarly, FIG5G illustrates schematic top and side views of component 20 positioned at a representative second off-center sidewall inspection position within inspection area 30 such that component center point 21 is closer to the second and fourth sidewall beam splitters 210b,d, than to the first and third sidewall beam splitters 210a,c.

When the component is positioned in the first off-center sidewall inspection position, (a) the first and third sidewall beam splitters 200a, c can be activated, while the second and fourth sidewall beam splitters 200b, d remain inactive. Thus, illumination output by the first and third sidewall illuminators 200a, c passes through the first and third sidewall beam splitters 210a-c, respectively, and is incident on the first and third component sidewalls 26a, 26c, where it is reflected by/from them as reflected sidewall illumination. The reflected sidewall illumination traveling away from the first and third component sidewalls 26a, c is redirected by the first and third sidewall beam splitters 210a, c, respectively, toward and reaches the image capture beam splitter 100, upon which the illumination is further directed toward and captured by the image capture device 400 as a first off-center image (e.g., a first off-center multi-sidewall image).

Because the second and fourth sidewall illuminators 200b, d remain inactive when the component 20 is positioned in the first decentered sidewall inspection position, no sidewall illumination from the second and fourth sidewall illuminators 200b, d is incident on the component 20 (e.g., on the second and fourth component sidewalls 26b, d, respectively) during the capture of the first decentered image. Furthermore, because the second and fourth sidewall beam splitters 210b, 210d are positioned relative to the first and third sidewall beam splitters 210a, 210c, respectively, reflections of illumination from the second and fourth component sidewalls 26b, d are significantly reduced, minimized, or essentially eliminated during the capture of the first decentered image. Consequently, extraneous sidewall illumination or optical crosstalk associated with the second and fourth sidewall beam splitters 210b, d is significantly reduced, minimized, or essentially eliminated during the capture of the first decentered image.

After the first off-center image is captured, the component 20 can be moved relative to the set of sidewall beam splitters 26a-d so that the component resides in a second off-center sidewall inspection position. When the component is positioned in the second off-center sidewall inspection position, (a) the second and fourth sidewall beam splitters 200b, d can be activated, while the first and third sidewall beam splitters 200a, c remain inactive. Thus, illumination output by the second and fourth sidewall illuminators 200b, d passes through the second and fourth sidewall beam splitters 210a-c, respectively, and is incident on the second and fourth component sidewalls 26b, 26d, whereupon the illumination is reflected by/from them as reflected sidewall illumination. The reflected sidewall illumination traveling away from the second and fourth component sidewalls 26b, d is redirected by the second and fourth sidewall beam splitters 210b, d, respectively, toward and reaches the image capture beam splitter 100, upon which the illumination is further directed toward and captured by the image capture device 400 as a second off-center image (e.g., a second off-center multi-sidewall image).

In a manner similar to that described above, because the first and third sidewall illuminators 200a, c remain inactive when the component 20 is positioned in the second decentered sidewall inspection position, no sidewall illumination from the first and third sidewall illuminators 200a, c is incident on the component 20 (e.g., on the first and third component sidewalls 26a, c, respectively) during the capture of the second decentered image. Furthermore, because the first and third sidewall beam splitters 210a, c are positioned relative to the second and fourth sidewall beam splitters 210b, d, respectively, reflections of illumination from the first and third component sidewalls 26a, c are significantly reduced, minimized, or substantially eliminated during the capture of the second decentered image. Consequently, extraneous sidewall illumination or optical crosstalk associated with the first and third sidewall beam splitters 210a, c is significantly reduced, minimized, or substantially eliminated during the capture of the second decentered image.

The ability to position a component 20 at multiple locations within the sidewall inspection area 30 enables the apparatus 10 according to embodiments of the present disclosure to successfully inspect a wide range of component 20 sizes with a single arrangement of sidewall beam splitters 210a-d. As a representative example, a square, approximately square, or rectangular component 20 having dimensions between approximately 0.3 cm and 3.0 cm on each side, or larger (e.g., up to approximately 7.0 cm or more, depending on the embodiment details or component inspection needs), can be sidewall inspected in the manner described herein using a single set of spaced-apart sidewall beam splitters 210a-d, thereby providing a total sidewall inspection area of approximately 3.5 cm x 3.5 cm. Thus, an owner or user of the apparatus 10 according to embodiments of the present disclosure does not need to acquire or purchase a large number of separate optical assemblies, each of which includes a set of sidewall beam splitters 210a-d configured to provide an inspection area 30 capable of accommodating a specific size or planar area (e.g., defined relative to the x-y plane), or a very limited range of sizes/planar areas. Thus, the cost of owning the apparatus 10 is significantly or greatly reduced compared to conventional inspection apparatus designs. More specifically, in conventional inspection apparatus 10 designs, a given optical assembly (e.g., of the type described above in connection with Figures 1A-1F) can be used only to inspect parts 20 having a narrow or very limited range of planar areas (e.g., a single planar dimension, or parts 20 having a very small range of planar dimensions). In contrast, an apparatus 10 according to embodiments of the present disclosure, which provides for multiple locations of part 20 within a sidewall inspection area 30, can accommodate parts 20 having a wider range of planar dimensions using a single or identical optical assembly.

Representative wavelength-separated sidewall illumination and inspection

In several embodiments, the apparatus 10 is configured such that (a) sidewall illumination traveling toward different or opposing sidewalls 26a-d of the component 20, and/or (b) reflected sidewall illumination traveling away from different or opposing sidewalls 26a-d of the component 20, respectively, exhibits different central wavelengths or wavelength ranges/bandwidths of light for those different or opposing component sidewalls 20a-d. Thus, the reflected sidewall illumination associated with different or opposing component sidewalls 26 traveling to the image capture device 400 exhibits multiple separate/dissociated central wavelengths or wavelength ranges in a manner corresponding to the particular sidewalls 26a-d from which such sidewall illumination originated. Depending on embodiment details, central wavelength or wavelength range separation may occur by sidewall illuminators 200a-d configured to output sidewall illumination having different central wavelengths or wavelength ranges of light; and/or optical filters (e.g., separate filter elements, or optical coatings), as further described below. In such an embodiment, the image capture device 400 is a color camera (e.g., an image capture device 400 that includes a color image sensor, in a manner readily understood by one of ordinary skill in the relevant art) that allows for (a) simultaneous capture of reflected sidewall illumination corresponding to each component sidewall 26 a-d in a single view during a single image capture operation, resulting in the generation of a single image in which sidewall image data (e.g., pixel data) clearly represents or contains useful information corresponding to each component sidewall 26 a-d; and (b) subsequent optical wavelength/bandwidth-based discrimination or compensation of the image data corresponding to each sidewall 26 a-d through an image processing operation as part of an automated component sidewall inspection operation.

In some embodiments, each sidewall illuminator 200a-d is configured to output illumination having a different central wavelength or wavelength range of light relative to each other sidewall illuminator 200a-d. Because the image capture device 400 includes a color image sensor, each sidewall illuminator 200a-d can be simultaneously activated during an image capture operation when the component 20 is positioned in the central sidewall inspection position. Thus, a single image capture operation can produce a single set of image data (e.g., pixel data) that clearly represents or contains useful information corresponding to each component sidewall 26a-d. As desired, digital discrimination or compensation operations based on optical wavelength or bandwidth may be performed on a single set of image data to reduce or essentially or effectively eliminate “optical crosstalk” associated with light of a different optical wavelength from each of the sidewall illuminators 200a,b,c,d, which passes through the corresponding sidewall beam splitter 210a,b,c,d and which is not incident on, and therefore not reflected by, the corresponding component sidewall 26a-d, but instead travels through or across the component 20 to the opposing sidewall beam splitter 210b,a,d,c and is received thereby as extraneous sidewall illumination and which is redirected due to beam splitting such that the extraneous sidewall illumination travels to the color image sensor, as further described below.

6A is a schematic top view illustrating a portion of a sidewall inspection apparatus 10 configured for performing a sidewall inspection process or technique for optical wavelength or bandwidth separation in accordance with an embodiment of the present disclosure. In one embodiment, the sidewall illumination passing through each sidewall beam splitter 210a-d toward a given component sidewall 26a-d is bandwidth-limited light having a different center frequency or wavelength relative to the sidewall illumination passing through each other sidewall beam splitter 210a-d toward each other corresponding component sidewall 26a-d. For example, in a representative embodiment, a first side wall illuminator 200a may output light with a bandwidth-limited (e.g., a substantially narrow, narrow, or very narrow bandwidth) centered at a red wavelength _λ1 (e.g., approximately 700 nm); a second side wall illuminator 200b may output light with a bandwidth-limited (e.g., a substantially narrow, narrow, or very narrow bandwidth) centered at a green wavelength _λ2 (e.g., approximately 550 nm); a third side wall illuminator 200c may output light with a bandwidth-limited (e.g., a substantially narrow, narrow, or very narrow bandwidth) centered at an orange wavelength _λ3 (e.g., approximately 600 nm); and a fourth side wall illuminator 200d may output light with a bandwidth-limited (e.g., a substantially narrow, narrow, or very narrow bandwidth) centered at a blue wavelength _λ4 (e.g., approximately 450 nm). In various embodiments, the bandwidth of each such central wavelength may be approximately 30 nm (or less) around the central wavelength. Such sidewall illumination may be provided by LEDs having appropriate wavelength output, and/or wavelength filters applied to the broad spectrum illumination (eg, white or substantially white light) produced by the sidewall illuminators 200a-d. As further described below with reference to FIGURE 6K, to simplify image data generation/collection and processing, in some embodiments, adjacent side wall illuminators 200a, c–200b, d/210a, d–210b, c may be activated in pairs such that (a) one pair of adjacent side wall illuminators 200a, c–200b, d/200a, d–200b, c may illuminate using light having a central wavelength of light λ1, while (b) another or corresponding pair of adjacent side wall illuminators 200a, c–200b, d/200a, d–200b, c may illuminate simultaneously using light having a different central wavelength of light λ2, and (c) within any given pair of opposing side wall illuminators 200a, b, 200c, d under consideration, the opposing side wall illuminators 200a, b, 200c, d may avoid illumination using light having the same central wavelength of light λ1 or λ2. Regardless of whether the embodiment of Figure 6A or the embodiment of Figure 6K is considered, due to appropriate optical wavelength or optical bandwidth separation, by subtracting pixel values within the range of pixel values corresponding to the optical wavelength or optical bandwidth of the foreign sidewall illumination from the sidewall image data corresponding to the reflected sidewall illumination captured by the particular sidewall beam splitter 210a,b,c,d under consideration, optical crosstalk can be reduced or eliminated, which is caused by the capture of the reflected sidewall illumination passing through any particular sidewall beam splitter 210a,a,c,d, which is performed simultaneously with the capture of foreign sidewall illumination that has passed through its opposite sidewall beam splitter 210b,a,d,c and has traveled across the sidewall inspection area 30 to that particular sidewall beam splitter 210a,b,c,d, thereby "contaminating" the sidewall image corresponding to that particular sidewall beam splitter 210a,b,c,d.

FIG. 6B schematically illustrates a representative wavelength-separated multi-sidewall image 500 captured as a single view (eg, in a single image capture operation) by the image capture device 400 through the wavelength-separated sidewall inspection apparatus 10 of FIG. 6A . Within this wavelength-separated multi-sidewall image 500, a first or left sidewall image or sidewall image region 510a corresponds to the first component sidewall 26a and has pixel values corresponding to a first central wavelength (e.g., 700 nm) output by the first sidewall illuminator 200a; a second or right sidewall image or sidewall image region 510b corresponds to the second component sidewall 26b and has pixel values corresponding to a second central wavelength (e.g., 550 nm) output by the second sidewall illuminator 200b; a third or upper sidewall image or sidewall image region 510c corresponds to the third component sidewall 26c and has pixel values corresponding to a third central wavelength (e.g., 600 nm) output by the third sidewall illuminator 200c; and a fourth or lower sidewall image or sidewall image region 510d corresponds to the fourth component sidewall 26d and has pixel values corresponding to a fourth central wavelength (e.g., 450 nm) output by the fourth sidewall illuminator 200d.

When the component 20 is positioned in the central sidewall inspection position, each component sidewall 26a-d can be illuminated by its corresponding sidewall illuminator 200a-d, and each component sidewall 26a-d can be simultaneously captured by the color camera 400 in a single image/as a single view (e.g., in a single image capture operation), thereby generating wavelength-separated multiple sidewall images that can be analyzed through image processing operations to identify defects (e.g., micro-defects, such as micro-cracks) in each sidewall 26a-d. Generally, by using appropriate central wavelength separation or separation between opposing or oppositely/oppositely oriented sidewall illuminators 200a-d, the effects of extraneous sidewall illumination on any given sidewall image region 510a-d can be reduced or minimized. Furthermore, by performing an appropriate calibration procedure for a given type of component 20 prior to initiation of a sidewall inspection operation, the effects of extraneous sidewall illumination on the pixel values corresponding to each sidewall image region 510a-d within the wavelength-separated multiple sidewall image 500 can be reduced, minimized, or effectively eliminated.

FIG6C is a schematic diagram illustrating a first sidewall illuminator activation pattern corresponding to a wavelength-separated sidewall inspection calibration procedure according to an embodiment of the present disclosure. During the first calibration operation, first sidewall illuminator 200a is activated when the other sidewall illuminators 200b-d are off; or at least, when second sidewall illuminator 200b is off and at least one of third and fourth sidewall illuminators 200c, 200d is off. For simplicity and to aid understanding, each of second through fourth sidewall illuminators 200b-c is defined as being off during the first calibration operation. Bandwidth-limited illumination having a first center wavelength output by first sidewall illuminator 200a passes through first sidewall illumination beam splitter 210a and is directed toward component 20 along an optical path parallel to the x-axis. Some of this illumination is reflected by first component sidewall 26a back to first sidewall beam splitter 210a, which redirects the reflected sidewall illumination toward image capture beam splitter 110. The reflective surface 112 of the image capture beam splitter then redirects the first bandwidth-limited illumination toward and into the lens assembly 300 and image capture device 400, and a first calibration image of the first sidewall 26a under the first bandwidth-limited illumination condition is captured. For example, when the first bandwidth-limited illumination corresponds to a light wavelength of 700 +/- 30 nm, the first calibration image of the first sidewall 26a can be defined as a "pure red" image.

6D is a schematic diagram of a second side wall illuminator activation pattern corresponding to a wavelength-separated side wall inspection calibration procedure according to an embodiment of the present disclosure. During the second calibration operation, the first and second side wall illuminators 200a, b, which are arranged relative to or opposite each other, are both activated. For simplicity and to aid understanding, the third and fourth side wall illuminators 200c, d are defined as being off during the second calibration operation. Because the first and second side wall illuminators 200a, b are activated during the second calibration operation, some of the first bandwidth-limited illumination from the first side wall illuminator 200a is reflected back by the first side wall 26a toward the first side wall beam splitter 210a. Additionally, some of the second bandwidth-limited illumination from second sidewall illuminator 200b will not be reflected by second sidewall 26b, but will instead travel through component 20 to first sidewall beam splitter 210a, thereby providing or contributing to the extraneous second bandwidth-limited sidewall illumination that will be present in the captured image of first sidewall 26a, in addition to the first bandwidth-limited illumination reflected from first sidewall 26a. That is, first sidewall beam splitter 210a redirects or reflects the first bandwidth-limited illumination and the extraneous second bandwidth-limited illumination reflected by first sidewall 26a toward image capture beam splitter 110, which redirects such first bandwidth-limited illumination and the extraneous second bandwidth-limited illumination toward and to lens assembly 300 and image capture device 400. A second calibration image of first sidewall 26a under the first bandwidth-limited illumination condition plus the extraneous second bandwidth-limited illumination is then captured. For example, when the first bandwidth limited illumination corresponds to a light wavelength of 700+/-30 nm and the second bandwidth limited illumination corresponds to a light wavelength of 550+/-30 nm, the second calibration image of the first sidewall 26a may be defined as a "pure red plus extraneous green" image.

Next, the first and second calibration images of first sidewall 26a are processed, compared, and/or analyzed relative to one another to detect or determine the magnitude of the effect, if any, of the extraneous second bandwidth-limited illumination in the second calibration image of first sidewall 26a relative to the first calibration image of sidewall 26a, and to eliminate such extraneous sidewall illumination. For example, in some embodiments, pixel values in the first calibration image are averaged, and pixel values in the second calibration image are averaged. The averaged pixel values corresponding to corresponding image locations in the first and second calibration images can be subtracted from one another to derive a first compensation factor, which can be digitally applied (e.g., as a subtraction operation) to a captured sidewall image or image region 510a corresponding to first sidewall 26a associated with a component inspection operation. That is, the first compensation factor can be applied (e.g., subtracted) to each pixel value within each first sidewall image region 510a of the wavelength-separated, multi-sidewall images captured during an actual component inspection operation. In other embodiments, pixel values in the first calibration image are directly subtracted from pixel values in the second calibration image, and the resulting difference or differential pixel values are averaged to derive a first compensation factor, which can be digitally applied (e.g., as a subtraction operation) to the captured sidewall image region 510a corresponding to the first sidewall 26a associated with the wavelength-separated component sidewall inspection operation. Depending on the details of the embodiment and/or the type of component 20 or component sidewall 26 under consideration, the compensation factor can be positive or negative, in a manner understood by one of ordinary skill in the relevant art.

The aforementioned type of calibration operation can then be performed to capture a third calibration image (e.g., a "pure green" image) of the second component sidewall 26b corresponding only to the second bandwidth-limited illumination, as indicated in FIG6E ; and a fourth calibration image (e.g., a "pure green plus extraneous red" image) of the second component sidewall 26b, as indicated in FIG6F . A second compensation factor can then be determined, for example, in the manner indicated above, which can be applied to the captured sidewall image region 510b corresponding to the second sidewall 26b associated with the wavelength-separated component sidewall inspection operation.

Similarly, the above-described type of calibration operation can be performed to capture a fifth calibration image (e.g., a "pure orange" image) of third component sidewall 26c corresponding only to the third bandwidth-limited illumination, as indicated in FIG6G ; and a sixth calibration image (e.g., a "pure orange plus extraneous blue" image) of third component sidewall 26c, as indicated in FIG6H . A third compensation factor can then be determined, for example, in the manner indicated above, and applied to captured sidewall image region 510c corresponding to third sidewall 26c associated with the wavelength-separated component sidewall inspection operation.

Finally, the above-described type of calibration operation can be performed to capture a seventh calibration image (e.g., a "pure blue" image) of fourth component sidewall 26d corresponding only to the fourth bandwidth-limited illumination, as indicated in FIG6I , and an eighth calibration image (e.g., a "pure blue plus extraneous orange" image) of fourth component sidewall 26d, as indicated in FIG6J . A fourth compensation factor can then be determined, such as in the manner indicated above, which can be applied to captured sidewall image region 510d corresponding to fourth sidewall 26d associated with the wavelength-separated component sidewall inspection operation.

It will be appreciated by one skilled in the relevant art that some of the aforementioned calibration operations may be combined, such as by selectively activating adjacent sidewall illuminators 200a, c/200b, d (or 200a, d/200b, c) at specific times. It will also be appreciated by one skilled in the relevant art that compensation factors may be determined for a given type of component 20 and may be stored in a memory, database, and/or data storage medium as part of an optical inspection method (e.g., a wavelength-separated component inspection method) for later retrieval. The appropriate inspection method may be retrieved or loaded as part of an inspection setup program in a manner readily understood by one skilled in the relevant art.

As noted above, in addition to or as an alternative to the foregoing, in some embodiments, each of the opposing sidewall illuminators 200a-d is configured to output sidewall illumination having different optical center wavelengths or bandwidths relative to one another, while non-opposing sidewall illuminators 200a-d are configured to output sidewall illumination having the same, substantially the same, or overlapping optical center wavelengths or bandwidths relative to one another. Thus, when a sidewall illuminator 200a-d is activated simultaneously with each other sidewall illuminator 200a-d, the sidewall illumination incident on the opposing component sidewalls 26a, b, 26c, d exhibits different optical center wavelengths or bandwidths. Thus, digital identification or compensation operations based on optical wavelength or bandwidth can once again be performed on a single captured image that includes image data that clearly represents and contains useful information corresponding to each component sidewall 26a-d in order to compensate for or essentially eliminate "optical crosstalk" associated with the opposing sidewall beam splitters 210a,b, 210c,d and their respective sidewall illuminators 200a,b,200c,d.

FIG6K is a schematic top view of a portion of a sidewall inspection apparatus 10 configured for performing a wavelength or bandwidth separated sidewall inspection process or technique according to another embodiment of the present disclosure. In this embodiment, opposing sidewall illuminators 200a, b, 200c, d are configured to output sidewall illumination having different optical center wavelengths or bandwidths. The sidewall illumination directed toward opposing component sidewalls 26a, b, 26c, d through opposing sidewall beam splitters 210a, b, 210c, d is bandwidth-limited light (e.g., light having substantially narrow, narrow, or very narrow bandwidths) having different optical center frequencies or wavelengths. The bandwidth of each center wavelength can be approximately 30 nm (or less) around the center wavelength. This sidewall illumination can be provided by LEDs having appropriate wavelength outputs and/or wavelength filters applied to the broad spectrum illumination (e.g., white/substantially white light) generated by the sidewall illuminators 200a-d.

In a representative embodiment including four side wall beam splitters 210a-d configured to receive side wall illumination outputs output by four corresponding side wall illuminators 200a-d, the relative first and second side wall illuminators 200a,b are respectively configured for passing directly or essentially directly therethrough, without redirection, side wall illumination having a first light center wavelength λ1 (e.g., red light centered at approximately 700nm) and a second light center wavelength λ2 (e.g., blue light centered at approximately 450nm); and the relative third and fourth side wall illuminators 200c,d are respectively configured for passing through therethrough, without redirection, side wall illumination having a first light center wavelength λ1 and a second light center wavelength λ2. Thus, incident side wall illumination centered at the first and second light wavelengths λ1 and λ2 is received toward the opposite first and second component side walls 26a, b through the first and second side wall beam splitters 210a, b, respectively; and incident side wall illumination centered at the first and second wavelengths λ1 and λ2 is received toward the opposite third and fourth component side walls 26c, d through the third and fourth side wall beam splitters 210c, d, respectively.

Thus, each component sidewall 26a-d can be illuminated simultaneously such that bandwidth-limited light having different, distinguishable optical center wavelengths λ1 and λ2 is received toward opposing component sidewalls 26a, b, 26c, d. With respect to illumination traveling away from component 20 and out of sidewall inspection region 30 to sidewall beam splitters 210a-d, any given sidewall beam splitter 210a-d receives (a) sidewall illumination reflected from its corresponding sidewall 26a-d at the same optical center wavelength λ1 or λ2 as that incident upon those sidewalls 26a-d, and (b) non-reflected exogenous illumination that propagates across sidewall inspection region 30 and has a different central wavelength λ2 or λ1 than that incident upon its corresponding sidewall 26a-d.

During a single image capture operation, the color image capture device 400 can capture, as a single view, the illumination that each sidewall beam splitter 210a-d has redirected toward the image capture beam splitter 110. The image capture device 400 accordingly generates a single set of image data, wherein pixel data that falls within or defines the image space representation of any given component sidewall 26a-d under consideration corresponds to one of the first and second optical center wavelengths λ1 or λ2; and pixel data that falls outside the image space boundaries of the component sidewall 26a-d under consideration corresponds to the other of the first and second optical center wavelengths λ2 or λ1. Furthermore, pixel data that falls within or defines the image space representation of any given pair of or facing opposite component sidewalls 26a-d corresponds to a different optical center wavelength, namely, λ1 or λ2. Thus, the pixel data representing first component sidewall 26a includes pixel values corresponding to the first light center wavelength λ1, but excludes or substantially excludes pixel values corresponding to the second light center wavelength λ2; and the pixel data representing second component sidewall 26b includes pixel values corresponding to the second light center wavelength λ2, but excludes pixel values corresponding to the first light center wavelength λ1. Similarly, the pixel data representing third component sidewall 26c includes pixel values corresponding to the first light center wavelength λ1, but excludes or substantially excludes pixel values corresponding to the second light center wavelength λ2; and the pixel data representing fourth component sidewall 26d includes pixel values corresponding to the second light center wavelength λ2, but excludes pixel values corresponding to the first light center wavelength λ1.

A digital pixel filtering or wavelength compensation operation may be applied to pixel data within different portions of a single set of image data associated with or as part of an automated sidewall inspection process (e.g., corresponding to different regions or quadrants in which the sidewall beam splitters 210a-d reside in real/physical space) to compensate for or effectively eliminate extraneous illumination or "optical crosstalk." Such a digital pixel filtering or wavelength compensation operation may include performing a pixel value subtraction operation on each different portion of the single set of image data, where the pixel value represents a particular component sidewall 26a-d that is present (or should/is expected to be present), such that for each such portion of the single set of image data, pixel values corresponding to a set of optical wavelengths or bandwidths associated with sidewall illumination of the periphery of each component sidewall 26a-d are subtracted therefrom, effectively eliminating the effects of "optical crosstalk." As stated above, this extraneous illumination or "optical crosstalk" is caused by the simultaneous transmission of sidewall illumination incident upon opposing component sidewalls 26a-d through oppositely disposed sidewall beam splitters 210a,b, 210c,d, but which is not reflected thereby and instead travels completely across the sidewall inspection area 30.

It will be understood by one skilled in the relevant art that calibration operations based on optical wavelength or bandwidth can be performed for the apparatus 10, such as that shown in FIG6K (e.g., if desired or needed), in a manner similar to that previously described above. It will also be understood by one skilled in the relevant art that, by virtue of the sidewall illuminators 200a-d being configured to output illumination having different distinguishable optical center wavelengths or bandwidths, and/or filters or coatings in the apparatus 10 (e.g., specific filters or coatings corresponding to specific sidewall beam splitters 210a-d), simultaneous (a) incident sidewall illumination supplied to the plurality of component sidewalls 26a-d, (b) redirection of sidewall illumination reflected from the plurality of component sidewalls 26a-d, and/or (c) propagation of reflected sidewall illumination in a wavelength-separated/discrete/specific manner (e.g., at different distinguishable optical center wavelengths or bandwidths) toward the image capture device 400 can occur.

Additional/Alternative Optional Component Positioning and Inspection Configurations

In various embodiments, the component holder 50 can additionally position the component 20 along the z-axis in an inspection position at a second, upper, or only front surface such that the component's sidewalls 26a-d, and possibly the entire component 20 itself, reside above a set of sidewall beam splitters 210a-d. Thus, the component 20 is not an obstruction with respect to light traveling along the lateral optical path between opposing sidewall beam splitters 210a, b, 210c, d.

More specifically, FIG7A illustrates a representative component positioned in a bottom-surface-only inspection position, wherein component 20 is positioned entirely above a set of sidewall beam splitters 210a-d. Brightfield illumination output by brightfield illuminator 100 can travel upward to component bottom surface 24 and be reflected by bottom surface 24 and the structure 28 carried thereby in a downward direction toward image capture beam splitter 110, thereby facilitating the capture of an image corresponding to component bottom surface 24. Brightfield illumination reaching any given sidewall beam splitter 210a-d is redirected by it toward the opposite sidewall beam splitter 210a-d. Because component 20 is positioned above sidewall beam splitters 210a-d, component sidewalls 26a-d are not imaged, as indicated in the accompanying image of FIG7A, which includes pixels corresponding to features associated with component front surface 20, but lacks pixels corresponding to structural aspects of component sidewalls 26a-d.

7B , the component holder 50 can additionally or alternatively position the component 20 at a sidewall inspection location (e.g., at least one sidewall inspection location within the sidewall inspection area 30) such that brightfield illumination or darkfield illumination output by the brightfield illuminator 100 or darkfield illuminator 120, respectively, can travel upward to the bottom surface 24 of the component and the structure 28 transported thereby and be reflected therefrom in a downward direction toward the image capture beam splitter 110, thereby facilitating the capture of an image corresponding to the bottom surface 24 of the component. The brightfield illumination or darkfield illumination can additionally travel to the sidewall beam splitters 210 a-d, where it is redirected along a path of travel toward the sidewalls 26 a-d of the component. A portion of this illumination is reflected back by the sidewalls 26 a-d of the component toward the sidewall beam splitters 210 a-d, which redirect this illumination in a downward direction toward the image capture beam splitter 110, thereby facilitating the capture of an image of the component sidewall. The representative captured image in FIG. 7B includes pixels corresponding to structures associated with the front surface 20 of the component, as well as pixels corresponding to structural aspects of the sidewalls 26a - d of the component.

Finally, as indicated in FIG7C , when in the sidewall inspection position, with the brightfield and darkfield illuminators 100 , 110 inactive or turned off, some or each of the sidewall beam splitters 200 a-d may be activated such that a part sidewall image may be captured in a manner substantially the same as or similar to one or more of the manners described above, as also indicated by the representative captured image in FIG7C .

In various embodiments, the vertical or z-axis difference between the bottom surface-only inspection position and the sidewall inspection position can be selected or determined so that the total optical path length corresponding to the in-focus image of the bottom surface 24 of the component captured when the component is in the bottom surface-only inspection position is equal to the optical path length corresponding to the in-focus image of the sidewalls 26 of the component when the component 20 is in the sidewall inspection position. For example, when the component 20 is in the bottom surface-only inspection position, the vertical or z-axis optical path length between the bottom surface 24 of the component 20 or front surface image plane 410 and the reflective plane 112 of the image capture beam splitter can be established so that it is equal to the lateral optical path length plus the vertical optical path length along which light reflected from the component sidewalls 26a-d travels to reach the reflective plane 112 of the image capture beam splitter. Thus, regardless of whether the component 20 is positioned in the bottom surface only inspection position or the sidewall inspection position, no changes in focus alignment or lens assembly adjustment are required, and no time or substantially/almost no time is lost because, in order to position the component 20 in the sidewall inspection position, the component 20 will have to reach or approach the bottom surface only inspection position before being inserted into the sidewall inspection position.

In addition to the foregoing, composite images of five sides can be generated to facilitate front surface and sidewall inspection. A composite image of five sides can be generated by digitally stitching together, for example, the central (e.g., bottom surface) image region corresponding to FIG. 7A and sidewall image regions corresponding to one or more multiple sidewall images, or sidewall image regions 510a-d corresponding to wavelength-separated image region multiple sidewall images. A representative composite image of five sides is shown in FIG. 7D.

Aspects of specific embodiments of the present disclosure address at least one aspect, problem, limitation and/or disadvantage associated with existing optical inspection systems that can capture images of component sidewalls. Although features, aspects and/or advantages associated with certain embodiments have been described in this disclosure, other embodiments may also display these features, aspects and/or advantages, and not all embodiments necessarily need to display these features, aspects and/or advantages to fall within the scope of this disclosure. It will be understood by those of ordinary skill in the art that several of the systems, components, processes, or alternative forms thereof disclosed above may be ideally combined into other different systems, components, processes, and/or applications. In addition, those of ordinary skill within the scope of this disclosure may make various modifications, changes, and/or improvements to the various disclosed embodiments.

Claims (27)

1. An apparatus configured for inspecting the surface of a component, including a component sidewall, the apparatus comprising: A set of side wall illuminators configured to input side wall illumination; A set of sidewall beam splitters is configured to: (a) Receive side wall illumination output from the set of side wall illuminators; (b) The sidewall illumination output by the set of sidewall illuminators is transmitted through the set of sidewall beamsplitters such that when the component is positioned in the sidewall inspection area of the sidewall inspection position, at least some of the sidewall illumination is incident on the sidewall of the component, at the sidewall inspection position, where the sidewall of the component blocks at least some of the optical paths between the individual sidewall beamsplitters in the set of sidewall beamsplitters. (c) When the component is positioned at the sidewall inspection position, receive sidewall illumination reflected from the sidewall of the component; (d) Reorienting the reflected sidewall illumination along the optical path corresponding to the lens assembly and image capturing device; and The processing unit is configured to selectively activate one or both of the following. (1) One or a pair of adjacent or opposite sidewall illuminators to capture an image of one or a pair of adjacent or opposite sidewalls when the other sidewall illuminators are not activated. (2) Independent center wavelength or bandwidth illumination of the sidewall illuminator for capturing a single image of the selected sidewall, or simultaneously capturing images of multiple sidewalls of the component sidewall. 2. The apparatus of claim 1, wherein the set of sidewall illuminators, the set of sidewall beam splitters, and the image capturing device are configured to capture images of the bottom surface of the component and/or images of the sidewalls of the component. 3. The apparatus of claim 1, wherein the set of sidewall illuminators comprises at least a pair of sidewall illuminators, wherein the two sidewall illuminators are positioned relative to each other relative to the sidewall inspection position. 4. The apparatus of claim 1, wherein the set of sidewall beam splitters comprises at least a pair of sidewall beam splitters disposed opposite each other on different sides of the sidewall inspection region relative to an axis defined by the sidewall inspection region. 5. The apparatus of claim 4, wherein the at least one pair of opposing sidewall beams includes a first sidewall beamsplitter and a second sidewall beamsplitter, wherein the first sidewall beamsplitter is configured to transmit first sidewall illumination having a first optical wavelength or a first optical bandwidth passing through it, and the second sidewall beamsplitter is configured to transmit second sidewall illumination having a different second optical wavelength or a second optical bandwidth passing through it, wherein the first sidewall beamsplitter is configured to receive and redirect each of a first reflected sidewall illumination from a first component sidewall and a second external sidewall illumination transmitted through the second sidewall beamsplitter, the second sidewall beamsplitter having traveled across the sidewall inspection region, and wherein the second sidewall beamsplitter is configured to receive and redirect each of a second reflected sidewall illumination from a second component sidewall and a first external sidewall illumination transmitted through the first sidewall beamsplitter, the first sidewall beamsplitter having traveled across the sidewall inspection region. 6. The apparatus according to claim 5, wherein: An image capturing device is configured to (a) capture a single image in a single image capturing operation, comprising a first image region corresponding to the first reflected sidewall illumination and the second external sidewall illumination, and a second image region corresponding to the second reflected sidewall illumination and the first external sidewall illumination, and (b) generate image data corresponding to the single image; and The processing unit is configured to process the image data such that pixel values corresponding to the second external sidewall illumination are digitally filtered from image data corresponding to the first image region, and pixel values corresponding to the first external sidewall illumination are digitally filtered from image data corresponding to the second image region. 7. The apparatus of claim 1, wherein the set of sidewall illuminators comprises a plurality of sidewall illuminators, wherein (a) each sidewall illuminator outputs illumination with the same optical center wavelength or bandwidth, or (b) a first subset of the sidewall illuminators outputs illumination with a different optical center wavelength or bandwidth relative to the illumination output by a second subset of the sidewall illuminators. 8. The apparatus of claim 1, wherein a specific subset of the sidewall illuminators within the set of sidewall illuminators may be selectively activated for outputting sidewall illumination, while other subsets of the sidewall illuminators within the set of sidewall illuminators remain inactive. 9. The apparatus of claim 1, further comprising a bright-field illuminator and/or a dark-field illuminator configured to selectively illuminate the bottom surface or the bottom surface and sidewall of a component located at the sidewall inspection position, wherein the sidewall of the component extends between the top surface of the component and the bottom surface of the component. 10. The apparatus of claim 9, further comprising an image capture beam splitter configured for... (a) Receive illumination output by the bright field illuminator and transmit bright field illumination passing through it; (b) Receive illumination of a bright field of view and/or a dark field of view reflected from the bottom surface and/or sidewall of the component; (c) Receiving sidewall illumination reflected from the component sidewall and redirected by the set of sidewall beam splitters; and (d) Reorient the received reflected illumination corresponding to (b) and (c) along the optical path toward the lens assembly. 11. The apparatus of claim 9, further comprising an image capturing device configured to receive illumination output from the lens assembly. 12. The apparatus of claim 11, wherein the image capturing device comprises a monochrome image sensor or a color image sensor. 13. The apparatus of claim 12, further comprising a component retainer configured to selectively position a component at the sidewall inspection location or only the bottom surface inspection location, wherein component interruption of the optical path between each sidewall beamsplitter is avoided at the sidewall inspection location or the bottom surface inspection location. 14. The apparatus of claim 13, wherein the component retainer is configured to selectively position a component thereby fixed at a plurality of sidewall inspection positions within the sidewall inspection area, the sidewall inspection positions including a first sidewall inspection position and a second sidewall inspection position, wherein at the first sidewall inspection position, the component center point is positioned closer to a first subset of the sidewall beam splitter than a different second subset of the sidewall beam splitter, and at the second sidewall inspection position, the component center point is positioned closer to a second subset of the sidewall beam splitter than the first subset of the sidewall beam splitter. 15. The apparatus of claim 12, wherein the processing unit is configured to selectively position the component at one or more inspection locations within the inspection area to capture one or more images of the component surface of the monochrome image sensor or the color image sensor. 16. A method for component inspection, comprising: A set of sidewall illuminators is provided, the illuminators being configured to output sidewall illumination at one or more center wavelengths or wavelength ranges; A set of sidewall beam splitters is provided, the sidewall beam splitters being configured to receive sidewall illumination output by the set of sidewall illuminators; A component is positioned at the first sidewall inspection location such that the sidewall of the component at least partially blocks at least some optical paths between the individual sidewall beamsplitters within the set of sidewall beamsplitters; Side wall illumination is directed toward the component sidewall by the side wall illumination received by the set of side wall beam splitters passing through it; When the component is stationed at the first sidewall inspection position, it receives sidewall illumination output by the set of sidewall beam splitters on the sidewalls of the plurality of components; Receive sidewall illumination reflected from the sidewalls of the plurality of components of the plurality of sidewall beam splitters; Redirecting the reflected sidewall illumination received by the plurality of sidewall beamsplitters along the optical path corresponding to a single image capturing device; and Selectively activate one or both of the following. (1) One or a pair of adjacent or opposite sidewall illuminators to capture an image of one or a pair of adjacent or opposite sidewalls when the other sidewall illuminators are not activated. (2) Independent center wavelength or bandwidth illumination of the sidewall illuminator for capturing a single image of the selected sidewall, or simultaneously capturing images of multiple sidewalls of the component sidewall. 17. The method of claim 16, further comprising selectively oriented sidewall illumination toward a first subset of the sidewalls of the component, while avoiding oriented sidewall illumination toward a second subset of the sidewalls of the component during the first image capture operation. 18. The method of claim 17, further comprising selectively oriented sidewall illumination toward a second subset of the sidewalls of the component, while avoiding oriented sidewall illumination toward a first subset of the sidewalls of the component during a second image capture operation. 19. The method of claim 16, further comprising: Capture a first image, the first image including pixel regions corresponding to a first subset of the component sidewalls; and A second image is captured, which includes pixel regions corresponding to a second subset of the component sidewalls. 20. The method of claim 19, further comprising generating a composite image by digitally stitching together portions of the first image corresponding to the first subset of the component sidewall and portions of the second image corresponding to the second subset of the component sidewall. 21. The method of claim 19, wherein capturing the first image occurs when the component is positioned at a first sidewall inspection position within a definable sidewall inspection area between the set of sidewall beam splitters, and capturing the second image occurs when the component is positioned at a different second sidewall inspection position within the sidewall inspection area. 22. The method of claim 21, wherein when the component is positioned at the first sidewall inspection position, the center point of the component is closer to a first subset of the sidewall beam splitters, and when the component is positioned at the second sidewall inspection position, the center point of the component is closer to a different second set of sidewall beam splitters. 23. The method of claim 16, wherein the sidewall illumination comprises a first sidewall illumination and a second sidewall illumination, and the reflected sidewall illumination comprises a first reflected sidewall illumination and a second reflected sidewall illumination, wherein the first sidewall illumination and the second sidewall illumination exhibit different bandwidth-limited wavelength ranges, and/or the first reflected sidewall illumination and the second reflected sidewall illumination exhibit different bandwidth-limited wavelength ranges. 24. The method of claim 23, further comprising capturing an image as a single view, the image comprising a plurality of different pixel regions, each pixel region corresponding to a different component sidewall, and each pixel region corresponding to one of at least two different bandwidth-limited optical path ranges. 25. The method of claim 24, further comprising performing a wavelength separation calibration procedure prior to capturing the image, the wavelength separation calibration procedure determining at least one calibration factor that can be applied to pixel regions corresponding to specific component sidewalls, thereby effectively eliminating the effects of external sidewall illumination in the captured image. 26. The method of claim 16, further comprising: When the component is stationed at the sidewall inspection position, capture at least one image including pixel regions corresponding to at least two component sidewalls; The component is moved to an inspection position on the bottom surface only, avoiding component interruption of the optical path between each sidewall beam splitter at either the first sidewall inspection position or the bottom surface inspection position. When the component is positioned at the bottom surface inspection location only, directional bright-field illumination and/or dark-field illumination are directed toward the bottom surface of the component; and Capture an image corresponding to the bottom surface of the component. 27. A method for inspecting a component having a plurality of sidewalls, the sidewalls comprising a first component sidewall and a second component sidewall facing opposite directions relative to each other along a first axis, the method comprising: The component is positioned at a sidewall inspection location within a sidewall inspection area between multiple sidewall beam splitters, the multiple sidewall beam splitters including a first sidewall beam splitter and a second sidewall beam splitter disposed on opposite sides of the sidewall inspection area along the first axis; The sidewall illumination is transmitted simultaneously by the multiple sidewall beam splitters, so that the first component sidewall and the second component sidewall receive the first incident sidewall illumination and the second incident sidewall illumination respectively at different optical center wavelengths or different optical bandwidths. The first sidewall beamsplitter receives (a) a first reflected sidewall illumination that travels away from the first component sidewall after the first incident sidewall illumination reaches it or is reflected from it, and (b) a second external sidewall illumination that has been transmitted through the second sidewall beamsplitter across the sidewall inspection area; the second sidewall beamsplitter receives (c) a second reflected sidewall illumination that travels away from the second component sidewall after the second incident sidewall illumination reaches it and is reflected from it, and (d) a first external sidewall illumination that has been transmitted through the first sidewall beamsplitter across the sidewall inspection area; Redirect each of the first reflected sidewall illumination, the second external sidewall illumination, the second reflected sidewall illumination, and the first external sidewall illumination toward a single image capture device; In a single image capture operation, the sidewall illumination of the first reflection as a single image and the second external sidewall illumination as a first region of the single image are captured, as well as the sidewall illumination of the second reflection as a second region of the single image and the first external sidewall illumination. Generate image data corresponding to the single image; and The image data is processed to digitally filter pixel values corresponding to the second external sidewall illumination from the first region of the single image and the first external sidewall illumination from the second region of the single image; wherein one or both of the following are selectively activated. One or a pair of adjacent or opposite sidewall illuminators are used to capture images of one or a pair of adjacent or opposite sidewalls when other sidewall illuminators are not activated. Independent center wavelength or bandwidth illumination of the sidewall illuminator for capturing a single image of a selected sidewall, or simultaneously capturing images of multiple sidewalls of the component sidewall.