TWI881180B - Appearance inspection device and method - Google Patents

Abstract

The purpose of the present invention is to provide an appearance inspection device and method that can obtain the desired inspection results without detecting suspected defects even if the inspection object includes a variable area that allows position deviation of the outer edge or size error. The present invention is an appearance inspection device for inspecting the appearance of an inspection object, comprising: an inspection image acquisition unit that acquires an inspection image; an inspection reference image registration unit that registers a reference image that serves as a reference for inspection; and an inspection unit that compares the inspection image with the reference image for inspection; and the inspection object includes a variable region that allows positional deviation or size error of the outer edge; and comprising: an edge detection unit that detects the outer edge position of the variable region; and a variable region reference image that is registered as a reference image and serves as an inspection reference for the variable region; The inspection unit compares the change area of the inspection image with the area corresponding to the position of the change area in the change area reference image based on the position of the outer edge detected by the edge detection unit to inspect the change area.

Description

Appearance inspection device and method

The present invention relates to an appearance inspection device and method for inspecting the inspection object by comparing and photographing an inspection image of the inspection object and a reference image. For example, the invention relates to a wafer appearance inspection device and method for photographing the appearance of a semiconductor element formed on a wafer and determining whether the semiconductor element is good or bad.

After semiconductor components are stacked on a semiconductor wafer to form multiple semiconductor component circuits (i.e., repeated appearance patterns of component chips), they are singulated into individual chip components, and the chip components are packaged and shipped as electronic components or incorporated into electrical products.

Furthermore, before each chip component is singulated, the inspection image and the reference image of the repeated appearance pattern of the component chip formed on the wafer are photographed to perform inspections on the quality of each chip component (for example, Patent Document 1).

In addition, there is a known technology that reduces erroneous detection caused by misalignment by aligning the inspection object image with the reference image before performing defect detection (e.g., Patent Document 2).

On the other hand, there is a known technique for performing subtraction processing (i.e., comparison) between the inspection image and the reference image, and masking and eliminating the noise generated by the deviation of the pattern matching at the image boundary (e.g., Patent Document 3).

[Prior Art Literature] [Patent Literature]

[Patent document 1] Japanese Patent Publication No. 2007-155610

[Patent Document 2] Japanese Patent Publication No. 2003-4427

[Patent document 3] Japanese Patent Publication No. 2000-335062

The inspection object, i.e., semiconductor components, includes multiple adjacent regions with different properties. For example, when a chip component is set as the inspection object, a wiring circuit pattern or external connection terminals (so-called electrode pads, ground portions) are formed on the surface of the wafer.

Because the wiring circuit diagram is deeply related to the performance of the component chip, strict inspection is required for broken or short circuits, differences in line width, and the mixing of foreign objects.

On the other hand, since the external connection terminals only need to be connected or connected to external components or leads, the position deviation or size error of the outer edge is not as strict as that of the wiring circuit diagram.

Therefore, when the inspection image of the inspection object includes an area (variable area) that allows the position deviation or size error of the outer edge, the position of the boundary (i.e., the outer edge) with the surrounding area (peripheral area) changes in each inspection image. As a result, when compared with the reference image, the part of the outer edge position change in the inspection image is detected as a defect (so-called suspected defect), which becomes the main reason for the decrease in the yield of component chips.

In addition, the prior art such as Patent Documents 2 and 3 is based on the premise that the size, range, pattern, etc. of the reference image are specific, and cannot cope with the situation where the size of the inspected part changes.

Therefore, the present invention is completed in view of the above-mentioned problems; the purpose is to provide an appearance inspection device and method that can obtain the desired inspection results without detecting suspected defects even if the inspection object includes a variable area that allows position deviation of the outer edge or size error.

In order to solve the above problems, one aspect of the present invention is an appearance inspection device, which photographs the appearance of the inspection object part and inspects it; and has: an inspection image acquisition unit, which acquires the appearance image of the inspection object part as the inspection image; an inspection reference image registration unit, which registers the reference image that serves as the reference for the inspection of the inspection object part; and an inspection unit, which compares the inspection image The inspection object is inspected with the reference image; and the inspection object includes a variable area where the position deviation or size error of the outer edge is allowed; and it has: An edge detection unit that processes the inspection image and detects the position of the outer edge of the variable area; and as a reference image, the outer edge of the variable area is recorded as being wider than the standard range that does not allow the position deviation or size error of the outer edge The inspection unit compares the inspection image with the inspection image based on the change area, and the inspection unit detects the change area of the change area. The moving area is inspected by comparing the position of the outer edge detected by the edge detection unit with the area corresponding to the position of the moving area in the moving area reference image; and the peripheral area of the inspection image is inspected by comparing the position of the outer edge of the moving area detected by the edge detection unit with the area corresponding to the position of the peripheral area in the peripheral area reference image.

Another aspect of the present invention is an appearance inspection method, which is a method for inspecting the inspection object by comparing an inspection image and a reference image taken of the appearance of the inspection object, and comprises: a reference image registration step, which pre-registers a reference image; an inspection image acquisition step, which acquires the inspection image; and an inspection step, which compares the inspection image and the reference image and compares the inspection object. The invention provides a method for inspecting a part of a device for inspection; and the inspection object part includes a variable area that allows positional deviation or size error of the outer edge; and has the following steps: as a reference image, registering a variable area reference image that is set to a wider range than the standard range that does not allow the positional deviation or size error of the outer edge, which serves as the inspection reference for the variable area; an edge detection step, which processes the inspection image The method comprises the steps of: detecting the position of the outer edge of the change area by recording the peripheral area reference image with the change area set to a range narrower than the standard range as the inspection reference of the peripheral area further outside the outer edge of the change area as the reference image; and comparing the change area of the inspection image with the peripheral area reference image obtained based on the edge detection step in the inspection step; The position of the detected outer edge is compared with the area corresponding to the position of the moving area in the moving area reference image to inspect the moving area; and the peripheral area of the inspection image is compared with the area corresponding to the position of the outer edge of the moving area detected based on the edge detection step and the peripheral area in the peripheral area reference image to inspect the peripheral area.

Even if the inspection object includes a variable area that allows positional deviation of the outer edge or dimensional error, the desired inspection result can be obtained without detecting suspected defects.

1: Wafer appearance inspection device

1f: Device frame

2: Inspection image acquisition unit

3: Check the base image registration department

4: Edge detection department

5: Inspection Department

B: Outer edge (border)

B1: Outer edge

B2: External edge

C: Component chip (chip parts)

EN:Controller

CP: Computer

F: Photography area (field of view)

H: Wafer holding part

H1: Loading platform

L1: Illumination light

L2: Light incident from the wafer side (reflected light, scattered light)

M: Relative moving part

M1: X-axis slide

M2: Y-axis slide

M3: Rotating mechanism

Pf: Baseline image

Pf1: Changing area baseline image

Pf2: Baseline image of the surrounding area

Px: Check image

Rs: Standard range

RP: Recipe Registration Department

Rx: Check the object's part

Rx1: Changing area (part of the inspection object)

Rx2: Peripheral area (part of the object to be examined)

S: Camera Department

S0: Lens barrel

S2: Semi-reflective mirror

S3a:Objective lens

S3b:Objective lens

S4: Objective lens rotator mechanism

S5: Video camera

s1~s7: Steps

s11~s18: Steps

Vs: Arrow

W: Wafer

FIG1 is an image diagram showing an example of an inspection image in an example of a form in which the present invention is embodied.

FIG2 is a schematic diagram showing the overall structure of an example of a form in which the present invention is embodied.

FIG3 is a conceptual diagram showing a situation of shooting an external image in an example of a form in which the present invention is embodied.

Figures 4(a) and (b) are image diagrams showing an example of a reference image in an example of a form in which the present invention is embodied.

Figure 5 (a) and (b) are flow charts of an example of a form in which the present invention is embodied.

The following is a description of the form used to implement the present invention using drawings. In the following description, the three axes of the orthogonal coordinate system are set as X, Y, and Z, the horizontal direction is represented as the X direction and the Y direction, and the direction perpendicular to the XY plane (i.e., the direction of gravity) is represented as the Z direction. In addition, the Z direction represents the direction opposite to gravity as up, and the direction in which gravity acts as down. In addition, the direction of rotation with the Z direction as the central axis is set as the θ direction.

FIG1 is an image diagram showing an example of an inspection image of an example of a form in which the present invention is embodied.

Figure 1 shows an example of an inspection image Px of the inspection target area Rx.

In addition, the inspection target part Rx includes a variable area Rx1 that allows position deviation or size error of the outer edge B, and a peripheral area Rx2 adjacent to the variable area Rx1.

In addition, in the following description, an example is shown in which, in the device chip C formed on the wafer W, the external connection terminal formed by the plating step is set as the variable area Rx1 in the inspection target part Rx, and the wiring circuit pattern is set as the peripheral area Rx2 in the inspection target part Rx.

FIG2 is a schematic diagram showing the overall structure of an example of a form in which the present invention is embodied. FIG2 schematically shows the various parts of the wafer appearance inspection device 1 of the present invention.

The wafer appearance inspection device 1 is used to photograph and inspect the appearance of the inspection target area Rx set on the surface of the wafer W. For example, it is configured to successively photograph the repeated appearance patterns of the component chip C (a type of semiconductor component) formed on the wafer W at specific intervals along the XY direction while obtaining the inspection image Px, and compare it with the pre-registered reference image Pf, thereby continuously inspecting the entire surface of the wafer W. Specifically, the wafer appearance inspection device 1 has an inspection image acquisition unit 2, an inspection reference image registration unit 3, an edge detection unit 4, and an inspection unit 5, etc.

More specifically, the wafer appearance inspection device 1 includes a wafer holding unit H, a camera unit S, a relative moving unit M, a computer CP, and a controller CN, etc.

The inspection image acquisition unit 2 acquires the external appearance image of the inspection object Rx as the inspection image Px. Specifically, the inspection image acquisition unit 2 is composed of the imaging unit S and the input unit of the computer CP.

FIG3 is a conceptual diagram showing the situation of photographing an external appearance image in an example of a form that embodies the present invention. FIG3 shows the situation in which a camera S5 of a photographing unit S moves relative to a wafer W in the direction indicated by an arrow Vs while sequentially photographing the external appearance of component chips C formed on the wafer W at specific intervals along the XY direction.

Specifically, during the relative movement of the relative moving part M (e.g., moving in the direction of the arrow Vs), the illumination part S1 flashes at a predetermined interval or position, and the camera S5 takes an external image that is the same as the still image. Furthermore, the external image output from the camera S5 is input as the inspection image Px to the input part of the computer CP (i.e., the inspection image Px is obtained).

The inspection reference image registration unit 3 registers the reference image Pf that serves as the inspection reference for the inspection target part Rx. Specifically, the inspection reference image registration unit 3 registers the variable area reference image Pf1 or the peripheral area reference image Pf2 as the reference image Pf.

More specifically, the inspection reference image registration unit 3 is composed of the memory unit or the auxiliary memory unit of the computer CP.

FIG. 4 is an image diagram showing an example of a reference image in an example of a form in which the present invention is embodied.

Figure 4(a) shows an example of one of the reference images Pf, namely, the variable area reference image Pf1.

Figure 4(b) shows an example of one of the reference images Pf, namely, the peripheral area reference image Pf2.

The variable area reference image Pf1 is used as the inspection reference for the variable area Rx1. The outer edge B1 of the variable area Rx1 is set to a wider range than the standard range Rs, which does not allow position deviation or size error of the outer edge. The outer edge B1 of the variable area Rx1 mentioned here is wider than the standard range Rs. It does not only refer to a wider area, but also refers to the state that the entire circumference of the outer edge B1 is located further outside the standard range Rs.

On the other hand, the peripheral area reference image Pf2 serves as the inspection reference for the peripheral area Rx2, and the outer edge B2 of the variable area Rx1 is set to a range narrower than the standard range Rs that does not allow positional deviation or size error of the outer edge. The outer edge B2 of the variable area Rx1 being narrower than the standard range Rs does not simply mean that the area is narrower, but refers to the state that the entire circumference of the outer edge B1 is located further inward than the standard range Rs.

In addition, the variation area reference image Pf1 or the peripheral area reference image Pf2 prepares and selects the limit sample of the variation of the outer edge B of the variation area Rx1 in advance, and pre-registers it in the inspection reference image registration unit 3.

The edge detection unit 4 processes the inspection image Px and detects the position of the outer edge B of the change area Rx1 (i.e., the boundary with the peripheral area Rx2).

Specifically, the edge detection unit 4 performs differential processing or differentiation processing on each pixel included in the inspection image Px, and outputs the position information of the pixel determined to be the outer edge B of the variable area Rx1.

More specifically, the edge detection unit 4 is composed of a processing unit or an image processing unit of a computer CP and an execution program.

The inspection unit 5 compares the inspection image Px with the reference image Pf and inspects the inspection target part Rx, that is, it compares the variable area Rx1 of the inspection image Px with the area corresponding to the position of the variable area Rx1 in the variable area reference image Pf1 based on the boundary position detected by the edge detection unit 4, and inspects the variable area Rx1.

Furthermore, the inspection unit 5 compares the peripheral area Rx2 of the inspection image Px with the area corresponding to the position of the peripheral area Rx2 in the peripheral area reference image Pf2 based on the boundary position detected by the edge detection unit 4, and inspects the peripheral area Rx2.

Specifically, the inspection unit 5 compares the brightness value of each pixel in the change area Rx1 of the inspection image Px with the brightness value of the pixel in the change area reference image Pf1 corresponding to the change area Rx1, and determines whether the brightness difference is within a specific range (i.e., within the qualified standard).

More specifically, the inspection unit 5 is composed of the processing unit or image processing unit of the computer CP and an execution program.

The wafer holding portion H holds the wafer W.

Specifically, the wafer holding part H holds and supports the wafer W in a horizontal state from the lower surface side. More specifically, the wafer holding part H has a horizontal mounting table H1 on the upper surface.

The mounting table H1 is provided with grooves or holes in the part in contact with the wafer W, and the grooves or holes are connected to a negative pressure generating mechanism such as a vacuum pump via a switching valve. Moreover, the wafer holding part H can hold or release the wafer W by switching the grooves or holes to a negative pressure state or a ventilation state.

The imaging unit S is used to capture the appearance of the inspected part and output image data. Specifically, the imaging unit S has a barrel S0, an illumination unit S1, a semi-reflective mirror S2, a plurality of objective lenses S3a, S3b, an objective lens rotator mechanism S4, and an imaging camera S5, etc.

The lens barrel S0 fixes the illumination unit S1, the semi-reflecting lens S2, the objective lens S3a, S3b, the objective lens rotator mechanism S4, the camera S5, etc. in a specific posture, and guides the illumination light L1 or the observation light L2. The lens barrel S0 is mounted on the device frame 1f via connecting metal parts (not shown).

The lighting unit S1 emits the lighting light L1 required for photography. Specifically, the lighting unit S1 can be exemplified by laser diodes or metal halogen lamps, xenon lamps, LED (Light Emitting Diode) lighting, etc. More specifically, the lighting unit S1 switches on/off based on external signal control, or flashes at specific locations or timings.

The semi-reflecting mirror S2 reflects the illumination light L1 emitted from the illumination unit S1 and irradiates it to the side of the wafer W, and allows the light (also called reflected light, scattered light, i.e. observation light) L2 incident from the side of the wafer W to pass to the side of the camera S5.

Objective lenses S3a and S3b are used to form images of the imaging area on the workpiece W at different specific observation magnifications on the imaging element of the imaging camera S5.

The objective lens rotator mechanism S4 uses or switches any one of the objective lenses S3a and S3b. Specifically, the objective lens rotator mechanism S4 is controlled manually or by external signals, and rotates and stops at each specific angle.

The camera S5 is used to photograph the photographing area F on the workpiece W to obtain the inspection image Px or the reference image Pf. The obtained images are output to the outside (in this embodiment, the computer CP) as image signals or image data.

The relative moving part M is used to make the wafer holding part H and the imaging part S move relative to each other.

Specifically, the relative moving part M is composed of an X-axis slider M1, a Y-axis slider M2, and a rotating mechanism M3.

The X-axis slider M1 is installed on the device frame 1f, so that the Y-axis slider M2 moves along the X direction at an arbitrary speed and stops at an arbitrary position. Specifically, the X-axis slider is composed of a pair of rails extending along the X direction, a slider part moving on the rails, and a slider driving part that moves and stops the slider part.

The Y-axis slider M2 is based on the control signal output from the controller CN, which enables the rotating mechanism M3 to move along the Y direction at any speed and to stop at any position. Specifically, the Y-axis slider is composed of a pair of rails extending along the Y direction, a slider part moving on the rails, and a slider driving part that moves and stops the slider part.

The slide drive parts of the X-axis slide M1 and the Y-axis slide M2 can be composed of a servo motor or a pulse motor and a ball screw mechanism that rotates and stops under the control of a signal from the controller CN, or a linear motor mechanism.

The rotating mechanism M3 is a mechanism that allows the stage H1 to rotate at any speed along the θ direction and to stop at any angle. Specifically, the rotating mechanism M3 can be exemplified as a mechanism that can rotate/stop at any angle by controlling a signal from an external device such as a direct drive motor. The stage H1 of the wafer holding unit H is mounted on the component on the rotating side of the rotating mechanism M3.

Since the relative moving part M is configured in this way, the wafer W can be moved relatively to the imaging part S along the XYθ directions independently or in combination at a specific speed or angle, or can be stationary at an arbitrary position or angle while the wafer W being the inspection object is maintained.

Computer CP is a computer that inputs signals or data from the outside, performs specific calculations or image processing, and outputs signals or data to the outside, and performs functions such as the following.

‧Login and switch of inspection image login mode and inspection mode (i.e. operation mode)

‧Check the image registration mode, recording magnification, registration, switching, etc.

‧Check the acquisition and registration of the reference image Pf in the image registration mode

‧Registering the inspection recipe of the inspection mode (shooting position or shooting sequence, shooting interval (distance, interval), moving speed, etc.), switching the inspection recipe used, etc.

‧Image processing of inspection image Px or reference image Pf

‧Inspection mode inspection: position detection (edge detection) of the outer edge B of the change area Rx in the inspection image Px or acquisition of the position information of the outer edge B, etc.

‧Comparison of the inspection image Px and the reference image Pf in the inspection mode (i.e., inspection)

More specifically, a computer CP is composed of an input and output unit, a memory unit (called a register or memory), a control unit and a calculation unit (called a CPU (Central Processing Unit) or an MPU (Micro Processor Unit)), an image processing device (called a GPU (Graphics Processing Unit)), an auxiliary memory device (HDD (Hard Disk Drive) or SSD (Solid State Disk) etc.) (i.e., hardware), and its execution program etc. (i.e., software).

The controller CN inputs and outputs signals or data with external devices (the imaging unit S or the various devices of the relative moving unit M, the computer CP, etc.), performs specific control processing, and executes functions such as the following.

‧Output the hold/release signal of wafer W to the wafer holding unit H

‧Control the objective lens rotator mechanism S4 to switch the objective lens to be used (photographic magnification)

‧Output a flashing light signal to the lighting unit S1

‧ Output shooting trigger for camera S5

‧Input the image output by the S5 selfie camera (check image or reference image)

‧Drive control of relative moving part M: monitor the current position of X-axis slider M1, Y-axis slider M2, and rotating mechanism M3, and output and control the driving signal function

That is, the controller CN can drive and control the relative moving part M, and output the imaging trigger to the imaging part S while changing the location of the imaging area F set on the wafer W. Furthermore, according to the inspection type, the imaging magnification or field of view size can be switched and the shooting interval can be changed while outputting the imaging trigger, so as to obtain the desired image.

In addition, the output of the image trigger can be illustrated in the following way.

‧While scanning and moving along the X direction, the illumination light L1 is made to emit light for a very short time (so-called flashing light) every time it moves a certain distance.

‧Moving and stopping at a specific position, irradiating the illumination light L1 and taking pictures (so-called step & repeat) method.

More specifically, the controller CN is composed of a part of the computer CP or a dedicated programmable logic controller (i.e. hardware) and its execution program (i.e. software).

<Operation mode and action flow>

The wafer appearance inspection device 1 has an inspection image registration mode and an inspection mode, which can be switched and operated.

Figure 5 is a flow chart showing an example of a form in which the present invention is embodied.

FIG5(a) shows a series of processes for using the wafer appearance inspection device 1 to capture and register an image (i.e., a reference image) as the inspection reference of the component chip C disposed on the wafer W in each action step. This is called the inspection image registration process, and the mode in which the following action flow is operated is the inspection image registration mode.

First, the wafer W for recording the reference image Pf is placed on the mounting table H1 of the wafer appearance inspection device 1 (step s1). The wafer W includes the component chip C that serves as the reference for quality judgment.

Next, read the alignment marks formed on the wafer W and align the wafer W (step s2).

Next, the relative moving part M is controlled to move the wafer W to a position (i.e., imaging position) where the imaging part S can capture the device chip C set as the reference image Pf (step s3).

Next, the camera unit S takes a reference image Pf, and registers the reference image Pf in the inspection reference image registration unit 3 (step s4). Specifically, the reference image Pf used to inspect the variable region Rx1 is registered as the variable region reference image Pf1.

Then determine whether to shoot and register the reference image (step s5), and repeat the above steps s3 to s5 when shooting and registering.

Specifically, the reference image Pf used to inspect the peripheral area Rx2 is registered as the peripheral area reference image Pf2. On the other hand, if there is no need to further shoot and register the reference image, the wafer W is released (step s6).

Furthermore, even for other wafers, it is determined whether to capture and register the reference image (step s7), and the above steps s1 to s7 are repeated when capturing and registering. On the other hand, if it is not necessary to capture and register the reference image, the series of processes ends.

FIG5(b) shows a series of processes in each action step, using the wafer appearance inspection device 1 to take the appearance image Px of the device chip C arranged on the wafer W, and performing inspection based on the image. This is called the inspection process, and the mode in which the following action process is operated is the inspection mode.

First, set up a new inspection recipe or select from a pre-registered inspection recipe and place the wafer W on the mounting table H1 (step s11).

Next, read the alignment marks formed on the wafer W and align the wafer W (step s12).

Next, the relative moving part M is controlled to move the wafer W while the imaging part S photographs the device chip C to obtain the inspection image Px (step s13).

Next, the edge detection unit 4 detects the position of the outer edge B of the change area Rx1 in the obtained inspection image Px (step s14).

Next, the inspection is performed by comparing the change area Rx1 in the inspection image Px with the area corresponding to the position of the change area Rx1 in the pre-registered change area reference image Pf1 (step s15). Specifically, the inspection unit 5 inspects the change area Rx1 by comparing the change area Rx1 in the inspection image Px with the area corresponding to the position of the change area Rx1 in the change area reference image Pf1 based on the position of the outer edge B of the change area Rx1 detected by the edge detection unit 4 in the inspection image Px.

Furthermore, the inspection is performed by comparing the peripheral area Rx2 of the inspection image Px with the area corresponding to the position of the peripheral area Rx2 of the pre-registered peripheral area reference image Pf2.

Specifically, the inspection unit 5 inspects the peripheral area Rx2 by comparing the peripheral area Rx2 of the inspection image Px with the area corresponding to the position of the peripheral area Rx2 in the peripheral area reference image Pf2 based on the position of the outer edge B of the change area Rx1 detected by the edge detection unit 4 of the inspection image Px.

Next, obtain other inspection images Px to determine whether to continue the inspection, etc. (step s16), and repeat the above steps s13~s16 when continuing the inspection, etc.

On the other hand, if there is no need to continue inspection, the wafer W is released (step s17).

Furthermore, even for other wafers, it is determined whether to obtain and inspect the inspection image (step s18), and the above steps s11 to s18 are repeated when further inspection is performed. On the other hand, if no further inspection is required, the series of processes ends.

Since the wafer appearance inspection device 1 of the present invention has such a structure, even if the inspection target portion Rx includes a variable area Rx1 that allows position deviation or size error of the outer edge, the desired inspection result can still be obtained without detecting suspected defects.

[Other forms and variations]

In the above, in addition to the change area Rx1 of the inspection image Px, the inspection unit 5 compares and inspects the peripheral area Rx2 with the area corresponding to the position of the peripheral area Rx2 in the peripheral area reference image Pf2 based on the position of the outer edge B detected by the edge detection unit 4.

However, in terms of the embodiment of the present invention, it is also possible to configure the inspection of the variable area Rx1 without the need to inspect the peripheral area Rx2.

In the above description, the inspection target part Rx is shown to be a semiconductor element formed on the wafer W, and as the variable area Rx1 of the inspection target part Rx, an example of an external connection terminal formed on the wafer W by a plating step is set.

In the plating step, the amount of deposited coating is not specific, so the line width or position accuracy of the wiring circuit pattern varies depending on the amount of deposited coating. In addition, the line width or position accuracy of the external connection terminals formed by the plating step is not as strictly specified as the wiring circuit pattern inside the component, and position deviation or dimensional accuracy is allowed.

Therefore, if such a part is set as the inspection object, the expected inspection result can be obtained without detecting suspected defects.

However, the present invention can be applied to the inspection of other inspection object parts in addition to the external connection terminals formed by the plating step.

In the above description, although the inspection target part Rx is set on the surface of the wafer W, it can also be set on the middle layer of the laminated substrate (such as the bonding surface). In this case, the imaging unit S only needs to appropriately select the wavelength of other laminated films or wafers as the illumination light L1 to irradiate the inspection target part, and the imaging camera S5 can obtain the observation light L2.

In addition, in the above, the example of the wafer appearance inspection device 1 is shown, which changes the imaging position of the wafer W in the XY direction where the component chip C to be inspected is arranged, and shoots (i.e. obtains) the inspection image Px.

However, after the present invention is embodied, the relative moving part M or the camera part S is not necessarily a configuration, and it can also be configured such that the inspection image Px sent from the host computer or external device storing the inspection image Px is received by the input part of the computer CP (i.e., acquired by the inspection image acquisition part 2), and the position of the outer edge of the variable area Rx1 included in the inspection image Px is detected by the edge detection part 4 in the same manner as above, and the inspection part 5 performs the same inspection as above (so-called off-line inspection).

1: Wafer appearance inspection device

1f: Device frame

2: Inspection image acquisition unit

3: Check the base image registration department

4: Edge detection department

5: Inspection Department

C: Component chip (chip parts)

EN:Controller

CP: Computer

F: Photography area (field of view)

H: Wafer holding part

H1: Loading platform

L1: lighting light

L2: Light incident from the wafer side (reflected light, scattered light)

M: Relative moving part

M1: X-axis slide

M2: Y-axis slide

M3: Rotating mechanism

Pf1: Changing area baseline image

Pf2: Baseline image of the surrounding area

Px: Check image

S: Camera Department

S0: Lens barrel

S2: Semi-reflective mirror

S3a:Objective lens

S3b:Objective lens

S4: Objective lens rotator mechanism

S5: Video camera

W: Wafer

Claims (3)

An appearance inspection device is characterized in that it photographs the appearance of an inspection target part and inspects it, and comprises: an inspection image acquisition unit, which acquires the appearance image of the inspection target part as an inspection image; an inspection reference image registration unit, which registers a reference image that serves as an inspection reference for the inspection target part; and an inspection unit, which compares the inspection image with the reference image and performs an inspection on the inspection target part. The device is provided with an edge detection unit for processing the inspection image to detect the position of the outer edge of the variable area; and the outer edge of the variable area is recorded as the reference image and is set to a wider range than the standard range that does not allow the position deviation or size error of the outer edge. The inspection unit compares the change area of the inspection image with the change area of the inspection image based on the edge detection unit. The position of the outer edge detected by the edge detection unit corresponds to the position of the changing area in the changing area reference image to inspect the changing area; and the peripheral area of the inspection image is compared with the position of the outer edge of the changing area detected by the edge detection unit and the area corresponding to the position of the peripheral area in the peripheral area reference image to inspect the peripheral area. As in claim 1, the appearance inspection device, wherein the inspection object part is a semiconductor element formed on a wafer, etc.; as the above-mentioned variable area in the above-mentioned inspection object part, there is provided an external connection terminal formed on the above-mentioned wafer by a plating step. A method for external inspection, characterized in that it is a method for inspecting the inspection object part by comparing an inspection image and a reference image taken of the external appearance of the inspection object part, and comprises: a reference image registration step, which pre-registers the reference image; an inspection image acquisition step, which acquires the inspection image; and an inspection step, which compares the inspection image and the reference image to inspect the inspection object part The method comprises the following steps: a step of recording, as the reference image, a reference image of the variable region in which the variable region is set to a wider range than the standard range in which the position deviation or size error of the outer edge is not allowed, and serving as the inspection reference for the variable region; and an edge detection step of processing the inspection image to detect the edge of the variable region. The method comprises the steps of recording, as the reference image, a peripheral region reference image in which the range of the variable region is set to be narrower than the standard range and serves as a reference for checking the peripheral region further outward from the peripheral region of the variable region; and in the checking step, comparing the variable region of the check image with the peripheral region reference image based on the edge detection. The moving area is inspected by comparing the position of the outer edge detected in the step with the area corresponding to the position of the moving area in the moving area reference image; and the peripheral area of the inspection image is inspected by comparing the position of the outer edge of the moving area detected in the edge detection step with the area corresponding to the position of the peripheral area in the peripheral area reference image.