JP2017053730A - Appearance inspection device and appearance inspection method - Google Patents

Abstract

An appearance inspection apparatus capable of inspecting a flat surface and a convex curved surface is provided.
A visual inspection apparatus includes a first unit for illuminating a first semiconductor element having a flat surface, and a second semiconductor element having a convex curved surface provided so as to be replaceable with the first unit. The first unit 30 is disposed between the imaging unit 40 and the first semiconductor element 20, the imaging unit 40 that images the first semiconductor element 20 and the surface of the second semiconductor element, and the imaging unit 40. And a transport unit 60 for disposing the second unit 50 between the imaging unit 40 and the second semiconductor element.
[Selection] Figure 1

Description

  Embodiments relate to an appearance inspection apparatus and an appearance inspection method.

  Some semiconductor elements such as a light emitting diode (LED) have a convex curved lens on the surface thereof. An illumination method different from that of an element having a flat surface is suitable for appearance inspection of such a semiconductor element. However, providing a plurality of appearance inspection apparatuses that match the surface shape of each semiconductor element causes an increase in manufacturing cost.

JP 2007-240431 A

  The embodiment provides an appearance inspection apparatus capable of inspecting a flat surface and a convex curved surface.

  An appearance inspection apparatus according to an embodiment illuminates a first unit for illuminating a first semiconductor element having a flat surface and a second semiconductor element which is provided so as to be replaceable with the first unit and has a convex curved surface. A second unit for imaging, an imaging unit for imaging the first semiconductor element and a surface of the second semiconductor element, the first unit disposed between the imaging unit and the first semiconductor element, and the imaging A transport unit for disposing the second unit between the unit and the second semiconductor element.

It is a schematic diagram which shows the external appearance inspection apparatus which concerns on embodiment. It is a schematic diagram which shows the illumination method of the external appearance inspection apparatus which concerns on embodiment. It is a schematic diagram which shows another illumination method of the external appearance inspection apparatus which concerns on embodiment. It is a schematic cross section which shows the illumination unit of the external appearance inspection apparatus which concerns on embodiment. It is a flowchart which shows the external appearance inspection method which concerns on embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. The same parts in the drawings are denoted by the same reference numerals, detailed description thereof will be omitted as appropriate, and different parts will be described. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawings.

  Furthermore, the arrangement and configuration of each part will be described using the X-axis, Y-axis, and Z-axis shown in each drawing. The X axis, the Y axis, and the Z axis are orthogonal to each other and represent the X direction, the Y direction, and the Z direction, respectively. Further, the Z direction may be described as the upper side and the opposite direction as the lower side.

  Drawing 1 is a mimetic diagram showing appearance inspection device 1 concerning an embodiment. As shown in FIG. 1, an inspection stage 10, a first illumination unit 30, and an imaging unit 40 are provided. The semiconductor element 20 is placed on the inspection stage 10. The first illumination unit 30 illuminates the semiconductor element 20 placed on the inspection stage 10. The imaging unit 40 images the surface of the semiconductor element 20 illuminated by the first lighting unit 30. For example, the imaging unit 40 is arranged such that the optical axis Cx is perpendicular to the surface of the inspection stage 10. The semiconductor element 20 is placed so as to be positioned on the optical axis Cx of the imaging unit 40.

  The semiconductor element 20 is, for example, an LED. The semiconductor element 20 may be placed directly on the inspection stage 10 or a tray containing a plurality of LEDs may be placed on the inspection stage 10. The semiconductor element 20 has, for example, a flat surface. Here, “flat” is not limited to the case where the entire upper surface of the semiconductor element 20 is flat. For example, it may have a plurality of planes and may have a step at the boundary.

  The 1st illumination unit 30 has the coaxial illumination part 31, the oblique illumination part 33, and the diffused light illumination part 35, for example. The first lighting unit 30 illuminates the surface of the semiconductor element 20 and enables imaging by the imaging unit 40. The coaxial illumination unit 31 illuminates the semiconductor element 20 with light propagating in a direction along the optical axis Cx of the imaging unit 40. The oblique illumination unit 33 illuminates the semiconductor element 20 with light propagating in a direction intersecting the optical axis Cx. The diffused light illumination unit 35 illuminates the semiconductor element 20 with diffused light that spreads in the propagation direction.

  The imaging unit 40 includes an imaging unit 41 and an imaging unit 43. The imaging unit 41 includes an optical lens 41a, and forms a surface image of the semiconductor element 20 on the imaging element 43a (see FIG. 2). The imaging unit 41 has a zoom function, for example, and enables imaging of the semiconductor elements 20 having different sizes. The imaging unit 43 includes, for example, a CCD (Charge Coupled Device) as the imaging element 43a.

  The appearance inspection apparatus 1 further includes a second illumination unit 50 and a transport unit 60. The second lighting unit 50 is provided to be replaceable with the first lighting unit 30. The transport unit 60 transports the first lighting unit 30 and the second lighting unit 50 to predetermined positions.

  The second illumination unit 50 includes a coaxial illumination unit 51 and a convex curved surface illumination unit 53. For example, the coaxial illumination unit 51 emits light propagating in a direction along the optical axis Cy perpendicular to the surface of the inspection stage 10. The convex curved surface illumination unit 53 has a plurality of light sources 57 (see FIG. 4). The plurality of light sources 57 are arranged so as to emit light propagating in different directions.

  The transport unit 60 transports, for example, the first lighting unit 30 and the second lighting unit 50 in the X direction and the −X direction. The transport unit 60 is provided so as to be movable in the X direction and the −X direction along a rail (not shown) extending in the X direction, for example.

  Next, an illumination method of the appearance inspection apparatus 1 according to the embodiment will be described with reference to FIGS. FIG. 2A to FIG. 2C are schematic diagrams illustrating an illumination method of the first illumination unit 30. FIG. FIG. 3A and FIG. 3B are schematic views showing the illumination method of the second illumination unit 50.

  As shown in FIGS. 2A to 2C, the first illumination unit 30 illuminates the semiconductor element 20 (first semiconductor element) having a flat surface. FIG. 2A shows an illumination method using the coaxial illumination unit 31. FIG. 2B shows an illumination method using the oblique illumination unit 33. FIG. 2C shows an illumination method using the diffused light illumination unit 35. 2A to 2C show an optical lens 41a and an image sensor 43a as elements indicating the image pickup unit 40. FIG.

As shown in FIG. 2A, the coaxial illumination unit 31 includes a light source 31a and a half mirror 31b. The light source 31a is a surface light source including a plurality of LEDs, for example. The half mirror 31b is disposed on the optical axis Cx. The light L ₁ emitted from the light source 31 a is reflected by the half mirror 31 b and travels in the direction of the semiconductor element 20. That is, the semiconductor device 20 is illuminated by light L ₁ propagating in the same direction as the optical axis Cx.

The light reflected by the surface of the semiconductor element 20 (reflected light L _R ) passes through the half mirror 31b and propagates in the direction of the imaging element 43a. Optical lens 41a is reflected light _{L R} focused to form an image of the surface image of the semiconductor device 20 on the imaging device 43a. The same applies to FIGS. 2B to 3B.

As shown in FIG. 2B, the oblique illumination unit 33 illuminates the semiconductor element 20 from obliquely above. Oblique illumination unit 33 includes, for example, a LED, which emits light _{L 2} propagating in the direction intersecting the optical axis Cx. For the oblique illumination unit 33, for example, an LED with high directivity is preferably used.

As shown in FIG. 2C, the diffused light illumination unit 35 illuminates the semiconductor element 20 with light that diffuses as it propagates (diffused light L ₃ ). For the diffused light illumination unit 35, for example, an LED having a lower directivity than the LED of the oblique illumination unit 33 is used. Diffuse illumination unit 35 is preferably incident angle of the diffused light L ₃ for the semiconductor element 20 is arranged in the larger position than the incident angle of the light L ₂ of the oblique illumination unit 33.

  As shown in FIGS. 3A and 3B, the second illumination unit 50 illuminates the semiconductor element 70 (second semiconductor element) having the convex curved surface 73. FIG. 3A shows an illumination method using the coaxial illumination unit 51. FIG. 3B shows an illumination method using the coaxial illumination unit 51 and the convex curved surface illumination unit 53. The second illumination unit 50 is arranged at a position where the optical axes Cx and Cy coincide with each other by the transport unit 60.

As shown in FIG. 3A, the coaxial illumination unit 51 includes a light source 51a and a half mirror 51b. The light source 51a is a surface light source including a plurality of LEDs, for example. The half mirror 51b is disposed on the optical axis Cx. The light L ₄ emitted from the light source 51 a is reflected by the half mirror 51 b and travels toward the semiconductor element 70. That is, the semiconductor element 70 is illuminated by the light L ₄ that propagates in the same direction as the optical axis Cx.

As shown in FIG. 3 (b), the semiconductor element 70 is emitted from the light L ₄ and the convex curved surface illumination unit 53 is emitted from the coaxial illuminating unit 51 is illuminated by a plurality of light L ₅ propagation directions are different. Light L ₅ of the convex curved surface illumination unit 53 is incident from different directions to the convex surface 73.

  FIG. 4 is a schematic cross-sectional view showing the second illumination unit 50 of the appearance inspection apparatus according to the embodiment. As shown in FIG. 4, the second illumination unit 50 includes a coaxial illumination unit 51 and a convex curved surface illumination unit 53 and illuminates the semiconductor element 70. The coaxial illumination unit 51 is provided on the convex curved surface illumination unit 53.

  The convex curved surface illumination unit 53 includes, for example, a housing 55, a plurality of light sources 57, and an optical window 59. The housing 55 is disposed at a position covering the semiconductor element 70 placed on the inspection stage 10. The housing 55 has a curved inner surface 55a, and the plurality of light sources 57 are uniformly arranged on the inner surface 55a. The plurality of light sources 57 are arranged, for example, so that each emitted light L5 propagates in a direction toward the semiconductor element 70 on the inspection stage 10. The plurality of light sources 57 are, for example, LEDs. The inner surface of the housing 55 is, for example, a hemispherical surface, and is provided so that its center is located on the surface of the inspection stage 10. The semiconductor element 70 is placed at the center of the hemispherical surface. Further, the inner surface of the housing 55 may be a concave surface provided so that the focal point is located on the surface of the inspection stage 10.

  The optical window 59 is provided in an opening 55c that communicates from the outer surface 55b of the housing 55 to the inner surface 55a. The optical window 59 is, for example, quartz glass. The housing 55 has, for example, a dome shape, and the optical window 59 is provided on the top thereof.

As shown in FIG. 4, the coaxial illumination unit 51 is provided on the optical window 59. The light L ₄ emitted from the coaxial illumination unit 51 passes through the optical window 59 and illuminates the semiconductor element 70. By illuminating the semiconductor element 70 using the light L _{4 from the} coaxial illumination unit 51 and the light L ₅ from the convex curve illumination unit 53, the entire surface of the convex curve 73 can be illuminated.

  As described above, by using the first illumination unit 30 and the second illumination unit 50, it is possible to perform suitable illumination for each of the semiconductor element 20 having a flat surface and the semiconductor element 70 having a convex curved surface. Thus, the accuracy of the appearance inspection can be improved. Further, by replacing the first illumination unit 30 and the second illumination unit 50 with each other by using the transport unit 60, the image pickup unit 40 can also be used. In addition, the appearance inspection apparatus can be reduced in size and price.

  The light source used for each illumination unit is, for example, a white LED. Moreover, you may use LED with a light wavelength of 600 nm or more. For example, when the semiconductor elements 20 and 50 have a resin containing a phosphor, it is preferable to use light in a wavelength band where the excitation efficiency of the phosphor is low. Thereby, the light emission of the phosphor can be suppressed and the inspection accuracy can be improved.

  Next, an appearance inspection method according to the embodiment will be described with reference to FIGS. FIG. 5 is a flowchart illustrating an appearance inspection method according to the embodiment. The appearance inspection method described below is executed by, for example, a computer (not shown) connected to each unit of the appearance inspection apparatus 1.

  Step S01: The type of the semiconductor element placed on the inspection stage 10 is detected. For example, it may be detected by analyzing a surface image picked up by the image pickup unit 40 or may be detected based on data input to a computer.

  Step S02: It is determined whether the surface of the semiconductor element is a flat surface or a convex curved surface. The presence or absence of a convex curved surface is determined based on the type of semiconductor element detected in step S01. If the surface of the semiconductor element is a flat surface (hereinafter referred to as semiconductor element 20), the process proceeds to step S03. If the semiconductor element has a convex curved surface (hereinafter referred to as semiconductor element 70), the process proceeds to step S08.

  Step S03: The first illumination unit 30 is disposed between the imaging unit 40 and the semiconductor element 20. For example, when the 1st illumination unit 30 is arrange | positioned between the imaging unit 40 and the semiconductor element 20, the state is maintained. When the second illumination unit 50 is disposed between the imaging unit 40 and the semiconductor element 20, the transport unit 60 is driven and replaced with the first illumination unit 30.

Step S04: The semiconductor element 20 is illuminated by the coaxial illumination unit 31, and a surface image of the semiconductor element 20 is acquired using the imaging unit 40. Illuminating the semiconductor element 20 by the light L ₁ propagating in the direction along the optical axis Cx of the imaging unit 40 captures the surface.

Step S05: The semiconductor element 20 is illuminated by the oblique illumination unit 33, and a surface image of the semiconductor element 20 is acquired using the imaging unit 40. The light L ₂ propagating in the direction crossing the optical axis Cx illuminates the semiconductor device 20, for imaging the surface. Further, the semiconductor element 20 may be illuminated using both the light L _{1 from} the coaxial illumination unit 31 and the light L _{2 from} the oblique illumination unit 33.

Step S06: The semiconductor element 20 is illuminated by the diffused light illumination unit 35, and a surface image of the semiconductor element 20 is acquired using the imaging unit 40. The semiconductor element 20 is illuminated with the diffused light L ₃ (diffused light) emitted from the diffused light illumination unit 35, and the surface of the semiconductor element 20 is imaged. In addition, the semiconductor element 20 may be illuminated using both the light L ₁ and the diffused light L _{3 from} the coaxial illumination unit 31.

  Step S07: The surface image acquired in Steps S04 to 06 is analyzed, and the quality of the semiconductor element 20 is determined. For example, the luminance distribution of the surface image is digitized, and a portion where the contrast exceeds a predetermined value is determined as a defect. And the semiconductor element 20 which does not have a defect is determined to be a non-defective product.

  Step S08: If it is determined in step S02 that the semiconductor element has the convex curved surface 73, the second illumination unit 50 is disposed between the imaging unit 40 and the semiconductor element 70.

Step S09: The semiconductor element 70 is illuminated by the coaxial illumination unit 51, and a surface image of the semiconductor element 70 is acquired using the imaging unit 40. Illuminating the semiconductor element 70 by the light L ₄ which propagates in a direction along the optical axis Cx of the imaging unit 40 captures the surface.

  Step S <b> 10: The semiconductor element 70 is illuminated by the coaxial illumination unit 51 and the convex curved surface illumination unit 53, and a surface image of the semiconductor element 70 is acquired using the imaging unit 40. Thereby, the surface image which illuminated the whole convex curve 73 from the different direction is acquirable.

  Then, it progresses to step S07 and the quality determination of the semiconductor element 70 is performed. In this embodiment, the accuracy can be improved by determining the presence or absence of a defect based on the surface image of the semiconductor element acquired by a different illumination method. The appearance inspection method described above is an example, and the present invention is not limited to this. For example, in the inspection using the first illumination unit 30, the oblique illumination unit 33 and the diffuse illumination unit 35 may be combined. Further, in the inspection using the second illumination unit 50, a surface image illuminated only by the convex curved surface illumination unit 53 may be acquired.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Appearance inspection apparatus, 10 ... Inspection stage, 20, 70 ... Semiconductor element, 30 ... 1st illumination unit, 31, 51 ... Coaxial illumination part, 31a, 51a, 57 ... -Light source, 31b, 51b ... Half mirror, 33 ... Oblique illumination part, 35 ... Diffuse light illumination part, 40 ... Imaging unit, 41 ... Imaging part, 41a ... Optical lens 43 ... Imaging unit, 43a ... Imaging element, 50 ... Second illumination unit, 53 ... Convex-curve illumination unit, 55 ... Housing, 55a ... Inner surface, 55b ... Outer surface, 55c ... opening, 59 ... optical window, 60 ... conveying unit, 73 ... convex curved surface, Cx, Cy ... optical axis

Claims (7)

A first unit for illuminating a first semiconductor element having a flat surface;
A second unit for illuminating a second semiconductor element having a convex curved surface, provided to be replaceable with the first unit;
An imaging unit that images surfaces of the first semiconductor element and the second semiconductor element;
A transport unit that arranges the first unit between the imaging unit and the first semiconductor element, and arranges the second unit between the imaging unit and the second semiconductor element;
Appearance inspection device with   The first unit includes a coaxial illumination unit that illuminates the first semiconductor element by light propagating in a direction along the optical axis of the imaging unit, and the first semiconductor by light propagating in a direction intersecting the optical axis. The visual inspection apparatus according to claim 1, further comprising an oblique illumination unit that illuminates the element.   The visual inspection apparatus according to claim 2, wherein the first unit further includes a diffuse illumination unit that illuminates the first semiconductor element with light that diffuses as it propagates.   The second unit illuminates the convex curved surface of the second semiconductor element from different directions with a coaxial illumination unit that illuminates the second semiconductor element with light propagating in a direction along the optical axis of the imaging unit. The appearance inspection apparatus according to claim 1, further comprising: a convex curved surface illumination unit including a plurality of light sources arranged so as to perform.   The appearance inspection apparatus according to claim 4, wherein the convex curved illumination unit includes a housing having a curved inner surface and the plurality of light sources attached to the inner surface. An imaging unit;
An illumination unit disposed on the optical axis of the imaging unit,
A first illumination unit that emits light propagating in a direction along the optical axis;
A second illumination unit comprising: an optical window disposed on the optical axis; a housing provided with the optical window; and a plurality of light sources disposed on an inner surface of the housing;
With
The light emitted from the first illumination unit illuminates the semiconductor element through the optical window,
The visual inspection apparatus in which the plurality of light sources are arranged to emit light toward the semiconductor element. Disposing a first unit for illuminating a flat surface of the semiconductor element or a second unit for illuminating a convex curved surface of the semiconductor element between the imaging unit and the semiconductor element;
Illuminating the semiconductor element with light propagating in a direction along the optical axis of the imaging unit, and imaging the semiconductor element;
Illuminating the flat surface with light propagating in a direction intersecting the optical axis, or illuminating the convex curved surface from a plurality of different directions to image the semiconductor element;
Appearance inspection method with

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