JP2001283194A - Method and device for inspecting appearance of circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for performing the highly precise appearance inspection of a semiconductor circuit board by correcting an inspection frame body pattern by a simple algorithm. SOLUTION: Circuit elements to be detected and a reference mark are selected for each of plural inspection areas arranged in the image pickup picture of a model circuit board, and an inspection frame pattern is formed in the outer peripheral line of the circuit element to be detected, and the picture data are registered in an RAM. At the time of inspecting the appearance of a semiconductor circuit board, the appearance inspection of circuit elements 23a and 23b to be detected is performed by a simple algorithm based on picture data between the reference pattern of each inspection field corresponding to plural inspection areas and the registered reference mark by highly precisely corrected inspection frame patterns so that the registered inspection frame patterns can be prevented from being affected by the deformation of the semiconductor circuit board. Thus, even when any three-dimensional deformation is generated in the semiconductor circuit board in manufacturing process, the highly precise appearance inspection of the semiconductor circuit board can be quickly and properly performed without being affected by the deformation of the semiconductor circuit board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board appearance inspection method for inspecting the appearance of a semiconductor circuit board by pattern matching based on a picked-up image of the semiconductor circuit board, and a semiconductor circuit for performing an inspection by the appearance inspection method. The present invention relates to a board appearance inspection device.

[0002]

2. Description of the Related Art Inspection of a semiconductor circuit board includes an electrical inspection for checking the continuity of a predetermined portion of the circuit element to be tested on the board and measuring a current / voltage value, and a pattern matching of the circuit element to be tested by an imaging camera. And visual inspection. According to the electrical inspection, the electrical characteristics of the semiconductor circuit board can be quantitatively grasped to determine the state. However, in this electrical inspection, the misalignment of the solder of the chip or package, the state of the defective solder, the state of the capacitor, etc. It is impossible to inspect the polarity, the presence or absence of a bypass capacitor, and the like.

In order to compensate for such omissions in the electrical inspection, an external appearance inspection using an imaging camera is performed. In this external appearance inspection, as shown in FIG. A plurality of inspection areas 20a to 20n are set for the non-defective model circuit board 7M, and a plurality of circuit elements to be inspected are generally selected in each of the inspection areas. On the basis of,
An inspection frame pattern corresponding to each circuit element to be tested is formed, and the image data of these circuit elements to be tested and the inspection frame pattern are stored in a registration memory in advance.

FIG. 7 shows a case where only the inspection area 20m is picked up from a plurality of inspection areas provided on the model circuit board 7M, and the reference marks 30a and 30b are formed on the model circuit board 7M in advance at opposing edges. Are provided, and coordinate data of the reference marks 30a and 30b with respect to the reference point 18 is stored in the registration memory in advance. Further, a circuit element 23m to be tested is selected in the test area 20m of the model circuit board 7M, a test frame pattern 22m is formed for the circuit element 23m to be tested, and the image data of the circuit element 23m to be tested and the test frame The image data of the pattern 22m is stored in the registration memory based on the coordinate data of the reference marks 30a and 30b.

At the time of inspection of the semiconductor circuit board 7 to be inspected, the semiconductor circuit board 7 is mounted on an inspection table, and FIG.
As shown in (a) and (b), for example, a captured image of the inspection area 20a in which the circuit elements 23a and 23b to be tested are selected is formed on the semiconductor circuit board 7, and the circuit to be tested is registered from the registration memory. Inspection frame pattern 22 of elements 23a and 23b
The image data a and 22b are read, and the inspection frame patterns 22a and 22b are superimposed and displayed on the semiconductor circuit board 7 to be inspected. In FIG. 8A, the deformation displacement of the semiconductor circuit board 7 to be inspected is equal to or less than a predetermined value, and the inspection frame pattern 22a
And the inspection frame pattern 22b coincide with the outer periphery of the circuit element 23b under predetermined matching conditions, respectively. The result of the appearance inspection of 20a is determined to be good.

On the other hand, in the case of FIG. 1B, since the semiconductor circuit substrate 7 to be inspected has been extended in the direction of arrow X during the manufacturing process, the inspection frame pattern 22a has the circuit element 23a to be inspected. The inspection frame pattern 22b deviates from the outer peripheral line of the circuit element 23b by more than a predetermined value, and the pattern deviation due to the deformation of the semiconductor circuit board 7 to be inspected is a predetermined value. In this state, the result of the appearance inspection of the inspection area 20a of the semiconductor circuit board 7 is determined to be defective. However, in this case, the external appearance of the circuit elements 23a and 23b to be inspected may be normal only when the semiconductor circuit board 7 to be inspected simply expands within an allowable range during the manufacturing process. In order to
It is necessary to correct the registered image data of the inspection frame patterns 22a and 22b in accordance with the expansion amount of the semiconductor circuit board 7 to make a matching determination.

[0007]

Incidentally, components may be mounted on a semiconductor circuit board 7 to be inspected by a reflow method in a manufacturing process. It is known that considerable heat causes considerable expansion and contraction and warpage. In the above-described conventional circuit board appearance inspection method, the image data of the circuit elements 23a and 23b in the inspection area 20a are obtained with reference to the reference marks 30a and 30b on the opposite edges of the model circuit board 7M.
The image data of the inspection frame patterns 22a and 22b are registered, and the correction processing of the image data of the inspection frame patterns 22a and 22b at the time of the inspection is performed on the reference mark provided on the edge of the semiconductor circuit board 7 to be inspected. The distance between the reference mark and the inspection frame pattern may be large, and if the three-dimensional deformation occurring on the semiconductor circuit board exceeds a predetermined value, the accuracy of the inspection frame pattern is determined based on the reference mark. Correction may not be possible. In order to solve this problem, it has been proposed to correct the inspection frame pattern for three-dimensional deformation of the semiconductor circuit board by using three reference marks at the edge of the semiconductor circuit board. The algorithm becomes complicated, and warpage and expansion and contraction rarely occur uniformly. Even with this method, the inspection frame pattern cannot be corrected with high accuracy against the deformation of the semiconductor circuit board.

SUMMARY OF THE INVENTION The present invention has been made in view of the present state of the above-described appearance inspection of a semiconductor circuit board, and a first object of the invention is to provide a step of correcting an inspection frame pattern by a simple algorithm, An object of the present invention is to provide a circuit board appearance inspection method capable of performing a highly accurate appearance inspection on a semiconductor circuit board. A second object of the present invention is to provide a circuit board appearance inspection apparatus capable of performing a highly accurate appearance inspection of a semiconductor circuit board by correcting an inspection frame pattern by a simple algorithm. It is in.

[0009]

In order to achieve the first object, according to the present invention, a plurality of inspection areas are formed on a model circuit board having the same configuration as a semiconductor circuit board to be inspected. Setting, selecting an element to be inspected and a reference mark for each of the set inspection areas, forming an inspection frame pattern based on an outer peripheral line of the element to be inspected, the inspection element, the reference mark and the inspection Register and store the image data of the frame pattern, for the semiconductor circuit board to be inspected, perform imaging by a camera for each inspection visual field corresponding to the inspection area, and a circuit element to be inspected corresponding to the element to be inspected, A circuit board appearance inspection method for performing an appearance inspection on the semiconductor circuit board to be inspected by performing pattern matching with the inspection frame pattern, wherein the camera performs the inspection. A reference pattern data detecting step of detecting image data of the reference pattern, based on a captured image of the reference pattern corresponding to the reference mark, obtained by imaging the target semiconductor circuit board; and an image of the reference mark registered in advance. Calculating the image data of the corrected inspection frame pattern by correcting the image data of the inspection frame pattern registered in advance based on the data and the image data of the reference pattern; and A correction inspection frame pattern forming step of forming a correction inspection frame pattern based on the image data;
An inspection step of performing an appearance inspection of the semiconductor circuit board to be inspected based on the modified inspection frame pattern.

According to such a means, in the reference pattern detecting step, image data of the reference pattern is obtained based on an image of the reference pattern corresponding to the reference mark, which is obtained by imaging the semiconductor circuit board to be inspected by the camera. In the calculation step, the image data of the pre-registered inspection frame pattern is corrected based on the image data of the pre-registered reference mark and the image data of the reference pattern, and the image data of the corrected inspection frame pattern is corrected. Is calculated. Then, in the correction inspection frame pattern forming step, based on the calculated image data of the correction inspection frame pattern,
A modified inspection frame pattern is formed, and in the inspection step, an appearance inspection of the semiconductor circuit board to be inspected is performed based on the modified inspection frame pattern. For this reason, even if there is a three-dimensional deformation occurring in the semiconductor circuit board to be inspected during the manufacturing process, the semiconductor circuit board is inspected in advance based on the image data of the reference pattern provided for each inspection visual field and the pre-registered reference marks. The registered inspection frame pattern is corrected by a simple algorithm with high accuracy so as to reduce the influence of the deformation of the semiconductor circuit board, and a corrected inspection frame pattern is obtained. The circuit elements to be inspected on the semiconductor circuit board are subjected to pattern matching, and a high-precision visual inspection is quickly and accurately performed on the semiconductor circuit board to be inspected.

[0011] Similarly, in order to achieve the first object,
The invention according to claim 2 is the invention according to claim 1,
In the reference pattern data detecting step, image data of the reference pattern is detected based on an infrared image of the reference pattern.

According to such a means, in addition to the effect of the first aspect of the invention, in the reference pattern data detecting step, an infrared image of the reference pattern of the semiconductor circuit board to be inspected taken by the camera is used. In a normal captured image, by using a pattern that does not provide a clear image as a reference pattern, high-precision image data of the reference pattern is detected, and the inspection frame pattern is corrected with high accuracy, thereby achieving higher accuracy. Is inspected.

According to a third aspect of the present invention, a plurality of inspection areas are set on a model circuit board having the same configuration as a semiconductor circuit board to be inspected.
For each set inspection area, an inspection target element and a reference mark are selected, an inspection frame pattern is formed based on an outer peripheral line of the inspection target element, and the inspection target element, the reference mark, and the inspection frame pattern are formed. Register and store image data,
For the semiconductor circuit board to be inspected, an image is taken by a camera for each inspection field of view corresponding to the inspection area, and pattern matching between the circuit element to be inspected corresponding to the element to be inspected and the inspection frame pattern is performed. A circuit board appearance inspection apparatus that performs an appearance inspection on the inspection target semiconductor circuit board, and is obtained by imaging the inspection target semiconductor circuit board by the camera and imaging a reference pattern corresponding to the reference mark. Based on the image, reference pattern data detection means for detecting the image data of the reference pattern, based on the previously registered image data of the reference mark, based on the image data of the reference pattern,
A calculating means for calculating image data of the corrected inspection frame pattern by correcting image data of the inspection frame pattern registered in advance; and forming a corrected inspection frame pattern based on the image data of the corrected inspection frame pattern. A modified inspection frame pattern forming means, and an inspection means for performing an appearance inspection of the semiconductor circuit board to be inspected based on the modified inspection frame pattern.

According to such means, the reference pattern detecting means obtains the image of the semiconductor circuit board to be inspected by the camera, and converts the image data of the reference pattern based on the image of the reference pattern corresponding to the reference mark. The image data of the registered inspection frame pattern is corrected based on the image data of the pre-registered reference mark and the image data of the reference pattern. Is calculated. The corrected inspection frame pattern is formed by the corrected inspection frame pattern forming means based on the image data of the corrected inspection frame pattern calculated, and the inspection target semiconductor circuit board is inspected by the inspection means based on the corrected inspection frame pattern. Is inspected. For this reason, even if there is a three-dimensional deformation occurring in the semiconductor circuit board to be inspected during the manufacturing process, the semiconductor circuit board is inspected in advance based on the image data of the reference pattern provided for each inspection visual field and the pre-registered reference marks. The registered inspection frame pattern can be
In order to reduce the influence of the deformation of the semiconductor circuit board, the circuit element to be inspected of the semiconductor circuit board to be inspected is subjected to pattern matching by the corrected inspection frame pattern corrected with high accuracy, and Quick and accurate high-precision visual inspection is performed.

Similarly, in order to achieve the second object,
The invention according to claim 4 is the invention according to claim 3,
The reference pattern data detecting means detects image data of the reference pattern based on an infrared image of the reference pattern.

According to such a means, in addition to the effect of the third aspect of the present invention, the reference pattern data detecting means can use the infrared image of the reference pattern of the semiconductor circuit board to be inspected which is imaged by the camera. In a normal captured image, by using a pattern that does not provide a clear image as a reference pattern, high-precision image data of the reference pattern is detected, and the inspection frame pattern is corrected with high accuracy, thereby achieving higher accuracy. Is inspected.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 to 6 based on an embodiment of a circuit board appearance inspection apparatus. 1 is a block diagram illustrating the configuration of the present embodiment, FIG. 2 is a diagram illustrating the configuration of the illumination unit in FIG. 1, FIG. 3 is a diagram illustrating the correction of coordinate data of an inspection frame pattern according to the present embodiment, FIG. 4 is an explanatory diagram showing a captured image at the time of appearance inspection according to the present embodiment, FIG. 5 is an explanatory diagram showing a normal captured image of an inspection region according to the present embodiment, and FIG. It is explanatory drawing which shows an infrared imaging image.

In this embodiment, as shown in FIG. 1, a Y stage 6 is arranged on a horizontal plane in the Y direction, and a sample table 9 is mounted on the Y stage 6 so as to be movable in the Y direction. ,
Above the sample stage 9, an illumination unit 2 having a shape of a cylindrical truncated pyramid is arranged. Also, as shown in FIGS. 2A and 2C, on the inner wall surface 17 of the lighting unit 2, a lighting board 15 a is provided in an upper part in a height direction, and a lighting board 15 b is provided in a middle part.
The lighting board 15c is fixedly arranged at the lower stage,
a has seven LEDs 16a as shown in FIG.
Are arranged, and similarly, seven L
The ED 16b is arranged, and seven LEs are provided on the lighting board 15c.
D16c is arranged. And these LED1
Of the 6a to 16c, only the LED 16a arranged on the upper side of the inner wall surface 17 is selected as an infrared LED that emits infrared light.

Further, an X stage 5 is disposed above the illumination unit 2 at right angles to the Y stage 6, and the X stage 5 has an imaging camera for imaging the semiconductor circuit board 7 mounted on the sample stage 9. The illumination unit 2 is attached to the imaging camera 1 along the X stage 5 so as to be movable in synchronization with the imaging camera 1. Further, an image forming circuit 19 that forms a captured image is connected to the imaging camera 1, and an X driver 3 that moves the imaging camera 1 along the X stage 5 is mounted on the X stage 5.
1 is provided.

On the other hand, in the present embodiment, a central control unit 10 for controlling the whole operation is provided. , A RAM 13 for writing and reading data during the visual inspection operation, a ROM 12 for storing a control operation program, and the image forming circuit 1 described above.
9. A monitor 11 on which various image data is displayed at the time of control operation, and an operation unit 4 to which an operation signal is inputted at the time of visual inspection
Is connected. Similarly, the central control unit 10 is connected via a bus B to a controller 3 that outputs control signals to various sections. The controller 3 includes an X driver 31 for moving the imaging camera 1 along the X stage 5,
Y driver 3 for moving sample stage 9 on Y stage 6
2. Camera control circuit 3 for controlling the operation of the imaging camera 1
0, and a lighting circuit 28 for controlling the operation of the lighting unit 2
Is connected. The output terminal of the X driver 31 and the output terminal of the Y driver 32 are connected to a coordinate detector 8 for detecting coordinate data, and the output terminal of the coordinate detector 8 is connected to the central control unit via a bus B. 10 is connected.

The operation of this embodiment having such a configuration will be described. In the present embodiment, prior to the appearance inspection of the semiconductor circuit board 7 to be inspected, a model circuit board 7M having the same configuration as the semiconductor circuit board 7 and having no deformation or defect and serving as a reference model for inspection is mounted on the sample table 9. Is done. Then, when the operator inputs a reference inspection command from the operation unit 4, the X-direction drive signal and the Y-direction drive signal output from the controller 3 are respectively changed to X-commands by the command of the central control unit 10.
The imaging camera 1 is moved to a predetermined position in the X direction with respect to the model circuit board 7M input to the driver 31 and the Y driver 32 and moved to a predetermined position in the Y axis direction on the Y stage 6, and the imaging camera 1 , For the model circuit board 7M,
It is arranged at a position where a previously set inspection area is used as an imaging field of view. Then, in this inspection area, the controller 3
A lighting driving signal is output from the lighting unit 28 and input to the lighting circuit 28, and the lighting circuit 28
The LEDs 16a to 16c of 5a to 15c emit light, and at the same time, the imaging camera 1 is operated by the imaging drive signal output from the controller 3 and the control signal issued from the camera control circuit 30. Imaging of the inspection area is performed. In the same manner, an image of each inspection area is sequentially taken using a plurality of inspection areas preset on the model circuit board 7M as a field of view.

By the way, on the model circuit board 7M, there are a wiring pattern, a silk screen using silk for a screen mesh, a chip component, a solder and the like.
Is a normal captured image 25 of the inspection area 20 captured by the imaging camera 1 as described above and the captured image is formed by the image forming circuit 19, and FIG. In a normal captured image 25,
Although it is not possible to image the wiring pattern on which the resist is applied, according to the infrared image 26, the wiring pattern is clearly imaged through the resist.

In this embodiment, the circuit element 23 and the reference pattern 27 are selected for each inspection area based on the captured image of the model circuit board 7M.
The inspection frame pattern 22 is formed based on the outer peripheral line of the inspection circuit element 23, the reference pattern 27, and the inspection frame pattern 2.
2 are registered and stored in the RAM 13. In this case, the inspection area 20 will be described. The operator operates the mouse while monitoring the infrared image 26 displayed on the monitor 11, and uses the mouse cursor to select the circuit to be inspected as a circuit element to be inspected for appearance. Element 23
a and 23b are selected and an inspection frame pattern forming signal is input from the operation unit 4, whereby an inspection frame pattern 22a is formed for the circuit element 23a to be inspected.
An inspection frame pattern 22b is formed for b. Further, the operator monitors the infrared imaged image 26 and selects, as the reference pattern 27, a wiring pattern having a peculiar shape not found in the inspection area 20 from among the wiring patterns.

Then, when the operator inputs a data registration command from the operation unit 4, the image data of the circuit elements 23 a and 23 b and the reference pattern 27 selected on the model circuit board 7 M and
The image data of the inspection frame patterns 22a and 22b formed based on the circuit elements 23a and 23b
One of the captured images is read and stored in the RAM 13. At this time, the operator designates the reference point 27b in the area shown in FIG. 3B with the mouse cursor and designates the correction reference point with the inspection frame patterns 22a and 22b.

In this state, the semiconductor circuit board 7 to be inspected having the same configuration as the model circuit board 7M is mounted on the sample table 9 instead of the model circuit board 7M, and the operator inputs a visual inspection command from the operation unit 4. Then, in response to a command from the central control unit 10, X output from the controller 3 is output.
The direction drive signal and the Y direction drive signal are input to the X driver 31 and the Y driver 32, respectively.
The imaging camera 1 is moved to a predetermined position in the X direction with respect to the semiconductor circuit board 7 moved to a predetermined position in the axial direction, and the imaging camera 1 is set in advance in the model circuit board 7M with respect to the semiconductor circuit board 7. The inspection area corresponding to the selected inspection area is arranged at a position where the imaging field of view is set. Then, in this inspection area, an illumination drive signal is output from the controller 3 and input to the illumination circuit 28, and infrared light from the LED 16 a of the illumination board 15 a of the illumination unit 2 is transmitted to the semiconductor circuit board 7.
In a state in which the imaging camera 1 is illuminated, the imaging camera 1 is operated by a control signal issued from the camera control circuit 30 by an imaging drive signal output from the controller 3, and
Accordingly, infrared imaging of the inspection area of the semiconductor circuit board 7 is performed, and similarly, the inspection areas of the semiconductor circuit board 7 corresponding to a plurality of inspection areas set in advance on the model circuit board 7M are sequentially set as imaging fields of view. Infrared imaging is performed.

FIG. 4 is an infrared image obtained by imaging the main part 20A of the inspection area of the semiconductor circuit board 7 corresponding to the infrared image of the inspection area 20 of the model circuit board 7M shown in FIG. In the infrared image, the inspection frame patterns 22a and 22b corresponding to the circuit elements 23a and 23b to be inspected are captured as clear images, and further, the reference pattern 27 selected in the inspection area.
Are captured as clear images. In the present embodiment, as described below, an inspection frame pattern for performing an appearance inspection of the circuit elements 23a and 23b to be inspected based on a reference point in the area designated in the reference pattern 27 selected as the inspection area. The correction of the images 22a and 22b is performed.

The main part 20 of the inspection area corresponding to the inspection area 20 of the model circuit board 7M of the semiconductor circuit board 7 shown in FIG.
A case where the appearance inspection of the circuit elements 23a and 23b to be tested will be described based on A,
When a reference data read command is input from the CPU, the coordinate data of the reference point 27b in the area of the reference pattern 27 already registered from the RAM 13 and the correction reference points of the inspection frame patterns 22a and 22b are inputted by the command of the central control unit 10. Is read. Here, as a screen display mechanism of a captured image, 640 × 4 widely used in a PC / AT mutual device.
VGA (Video Graphi) with a resolution of 80 dots
csArray) and a case where the inspection frame pattern 22a is corrected will be described. In this case, the coordinate data of the registered reference point 27b in the area of the registered reference pattern 27 is (X: 300Y: 250), and the inspection frame pattern 2
The coordinate data of the correction reference point 2a is (X: 100 Y: 1
00), a reference pattern 27 obtained from a captured image of the main part 20A of the inspection area of the semiconductor circuit board 7 to be inspected.
The coordinate data of the reference point 27b in the area of (X: 310Y:
240).

In the present embodiment, the coordinate data (Xm, Ym) of the inspection frame pattern corrected in accordance with the deformation of the semiconductor circuit board 7 during manufacturing, the registered coordinate data (Xs, Ys) of the reference pattern, and The coordinate data (X, X) of the inspection frame pattern read from the captured image of the semiconductor circuit board 7
Since the reference pattern exists in the inspection area between Y) and the distance between the reference pattern and the inspection frame pattern is sufficiently small, there is a relationship represented by Expression (1).

(Xm, Ym) = (Xs, Ys) + {(Xs−X), (Ys−Y)} (1)

Therefore, in the embodiment, the coordinate data Xm, Ym of the inspection frame pattern to be corrected is calculated by the following equation in accordance with a command from the central control unit 10.

Xm = 100 + (310−300) = 110 (2) Ym = 100 + (240−250) = 90 (3)

In this case, it is also possible to perform sub-pixel processing for pattern matching and correct the inspection frame pattern with resolution accuracy of one pixel or less.

The test frame elements 23a and 22b corrected in this manner are used as test target circuit elements 23.
a and 23b are visually inspected by pattern matching, respectively, and when the arithmetic unit 14 satisfies the condition for matching a predetermined number or more of coordinate points,
The semiconductor circuit board 7 to be inspected is determined to be non-defective in the appearance inspection.

As described above, according to the present embodiment, a plurality of inspection areas are provided in advance on the model circuit board 7M based on the captured image of the model circuit board 7M. A reference pattern is selected and an inspection frame pattern is formed. For example, for the inspection area 20,
As shown in FIG. 6, the circuit elements under test 23a and 23b and the reference pattern 27 are selected, and the inspection frame patterns 22a and 22b are selected.
b is formed, and the image data of the test circuit patterns 23a and 23b, the reference pattern 27, and the test frame patterns 22a and 22b are stored in the RAM 13. Then, the sensor frame pattern 22a whose appearance inspection of the test circuit patterns 23a and 23b of the semiconductor circuit board 7 is corrected based on the difference between the reference pattern 27 provided in the same inspection area and the registered value on the model circuit board 7M, 22b, based on image data of a reference pattern provided for each inspection field and a reference mark registered on the model circuit board, even when there is a three-dimensional deformation occurring in the semiconductor circuit board 7 during the manufacturing process. The inspection frame pattern registered in advance on the semiconductor circuit board 7 is modified by a highly accurate modified inspection frame pattern so that the effect of the deformation of the semiconductor circuit board is reduced by a simple algorithm. 22a,
Since the pattern matching is performed on the pattern 22b, the appearance of the semiconductor circuit board 7 can be inspected quickly and accurately with high accuracy. Further, since the coordinate values are corrected based on the actually picked-up image, the appearance inspection can be performed without being affected by the disturbance of the image capturing by the imaging camera 1, and the inspection can be performed at high speed. It is possible to easily cope with the change.

[0035]

According to the first aspect of the present invention, a plurality of inspection areas are set and set in advance on a model circuit board having the same configuration as the semiconductor circuit board to be inspected. For each of the inspection areas, an inspection target element and a reference mark are selected, an inspection frame pattern is formed based on the outer peripheral line of the captured image of the inspection target element, and the image data of the inspection target element, the reference mark, and the inspection frame pattern are displayed. Registered and stored, at the time of inspection, a semiconductor circuit board to be inspected is imaged by a camera for each inspection visual field corresponding to the inspection area, and an image of a circuit element to be inspected corresponding to the element to be inspected, By performing matching with a registered inspection frame pattern, an appearance inspection is performed on the semiconductor circuit board to be inspected.

In this case, in the reference pattern detecting step,
The image data of the reference pattern is detected based on a captured image of the reference pattern corresponding to the reference mark, which is obtained by imaging the semiconductor circuit board to be inspected by the camera, and in the calculation step, the image data of the reference mark registered in advance is calculated. The image data of the inspection frame pattern registered in advance is corrected based on the image data of the reference pattern and the image data of the reference pattern, and the image data of the corrected inspection frame pattern is calculated. Then, in the modified inspection frame pattern forming step, a modified inspection frame pattern is formed based on the calculated image data of the modified inspection frame pattern. In the inspection step, the semiconductor circuit board to be inspected is formed based on the modified inspection frame pattern. Is inspected.

For this reason, even when the semiconductor circuit board to be inspected has a three-dimensional deformation occurring during the manufacturing process, it is determined based on the image data of the reference patterns provided for each inspection field and the reference marks registered in advance. Therefore, the inspection frame pattern registered on the model circuit board is reduced by a simple algorithm so as to reduce the influence of the deformation of the semiconductor circuit board.
Since a corrected inspection frame pattern corrected with high precision can be obtained, the circuit elements to be inspected of the semiconductor circuit board to be inspected are pattern-matched by this modified inspection frame pattern, and the inspection circuit element can be quickly and quickly applied to the semiconductor circuit board to be inspected. Appropriately high-precision appearance inspection can be performed.

According to the second aspect of the present invention, in addition to the effect obtained by the first aspect of the present invention, in the reference pattern data detecting step, the infrared ray of the reference pattern obtained by imaging the semiconductor circuit board to be inspected by the camera. By using a pattern that does not provide a clear image in a normal captured image as a reference pattern by the captured image, high-precision image data of the reference pattern is detected, and the inspection frame pattern is corrected with high accuracy. This makes it possible to perform a more accurate appearance inspection.

According to the third aspect of the present invention, a plurality of inspection areas are set in advance on a model circuit board having the same configuration as the semiconductor circuit board to be inspected. An inspection target element and a reference mark are selected for each inspection area, an inspection frame pattern is formed based on the outer peripheral line of a captured image of the inspection target element, and image data of the inspection target element, the reference mark, and the inspection frame pattern are registered and stored. At the time of inspection, an image of the semiconductor circuit board to be inspected is taken by a camera for each inspection field of view corresponding to the inspection area, and an image of the circuit element to be inspected corresponding to the element to be inspected is registered. By performing matching with the existing inspection frame pattern, an appearance inspection is performed on the semiconductor circuit board to be inspected.

In this case, the reference pattern detecting means
The image data of the reference pattern is detected based on a captured image of the reference pattern corresponding to the reference mark, which is obtained by imaging the semiconductor circuit board to be inspected by the camera, and the image data of the reference mark registered in advance by the arithmetic unit The registered image data of the inspection frame pattern is corrected based on the image data of the reference pattern and the image data of the reference pattern, and the image data of the corrected inspection frame pattern is calculated. The corrected inspection frame pattern is formed by the corrected inspection frame pattern forming means based on the image data of the corrected inspection frame pattern calculated, and the inspection target semiconductor circuit board is inspected by the inspection means based on the corrected inspection frame pattern. Is inspected.

For this reason, even when the semiconductor circuit board to be inspected has a three-dimensional deformation that occurs during the manufacturing process, the image data of the reference pattern provided for each inspection field and the reference marks registered in advance are not included. Based on the inspection frame pattern registered in advance, a simple algorithm can be used to obtain a corrected inspection frame pattern that is corrected with high accuracy so as to reduce the influence of the deformation of the semiconductor circuit board. As a result, the circuit elements to be inspected of the semiconductor circuit board to be inspected are subjected to pattern matching, and a high-precision visual inspection can be quickly and accurately performed on the semiconductor circuit board to be inspected.

According to the fourth aspect of the present invention, in addition to the effect of the third aspect of the present invention, an infrared image of the reference pattern of the semiconductor circuit board to be inspected taken by the camera by the reference pattern data detecting means. By using a pattern in which a clear image is not obtained in a normal captured image as a reference pattern, high-precision image data of the reference pattern is detected, and the inspection frame pattern is corrected with high accuracy. High-precision appearance inspection can be performed.

[Brief description of the drawings]

FIG. 1 is an explanatory block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a configuration of a lighting unit in FIG. 1;

FIG. 3 is an explanatory diagram of correction of coordinate data of an inspection frame pattern according to the embodiment.

FIG. 4 is an explanatory diagram showing a captured image at the time of an appearance inspection according to the embodiment.

FIG. 5 is an explanatory diagram showing a normal captured image of an inspection area according to the embodiment.

FIG. 6 is an explanatory diagram showing an infrared image of an inspection area according to the embodiment;

FIG. 7 is an explanatory diagram of a conventional visual inspection of a semiconductor circuit board.

FIG. 8 is an explanatory diagram of a captured image at the time of a conventional appearance inspection of a semiconductor circuit board.

[Explanation of symbols]

1. Imaging camera, 2. Illumination unit, 3. Controller, 4. Operation unit, 5. X stage, 6. Y stage, 7, Semiconductor circuit board, 9, Sample table, 10.
· Central control unit, 11 · · Monitor, 13 · · RA
M, 14 arithmetic unit, 18 reference point, 20 inspection area, 22a, 22b inspection frame pattern, 23a, 23
b: circuit element to be tested, 27: reference pattern.

Claims (4)

[Claims] 1. A plurality of inspection areas are set for a model circuit board having the same configuration as a semiconductor circuit board to be inspected, and an element to be inspected and a reference mark are selected for each of the set inspection areas. An inspection frame pattern is formed based on an outer peripheral line of the inspection target element, image data of the inspection target element, the reference mark, and the inspection frame pattern are registered and stored, and the inspection is performed on the inspection target semiconductor circuit board. An image is inspected by a camera for each inspection visual field corresponding to the area, and a pattern matching is performed between the circuit element to be inspected corresponding to the element to be inspected and the inspection frame pattern, so that an appearance inspection for the semiconductor circuit board to be inspected is performed. A method for inspecting the appearance of a circuit board, the method comprising: obtaining an image of the semiconductor circuit board to be inspected by the camera; A reference pattern data detecting step of detecting image data of the reference pattern based on a captured image of the pattern, image data of the reference mark registered in advance, and image data of the reference pattern, By correcting the image data of the inspection frame pattern,
A calculating step of calculating image data of the corrected inspection frame pattern; a correction inspection frame pattern forming step of forming a corrected inspection frame pattern based on the image data of the corrected inspection frame pattern; and An inspection step of performing an appearance inspection of the semiconductor circuit board to be inspected. 2. The method according to claim 1, wherein in the reference pattern data detecting step, image data of the reference pattern is detected based on an infrared image of the reference pattern. 3. A plurality of inspection areas are set on a model circuit board having the same configuration as a semiconductor circuit board to be inspected, and an element to be inspected and a reference mark are selected for each of the set inspection areas. An inspection frame pattern is formed based on an outer peripheral line of the inspection target element, image data of the inspection target element, the reference mark, and the inspection frame pattern are registered and stored, and the inspection is performed on the inspection target semiconductor circuit board. An image is inspected by a camera for each inspection visual field corresponding to the area, and a pattern matching is performed between the circuit element to be inspected corresponding to the element to be inspected and the inspection frame pattern, so that an appearance inspection for the semiconductor circuit board to be inspected is performed. A circuit board appearance inspection apparatus that performs imaging, and that is obtained by imaging the semiconductor circuit board to be inspected by the camera and that corresponds to the reference mark. A reference pattern data detecting means for detecting image data of the reference pattern based on a captured image of the pattern; image data of the reference mark registered in advance; and image data of the reference pattern registered in advance based on the image data of the reference pattern. By correcting the image data of the inspection frame pattern,
Calculating means for calculating the image data of the modified inspection frame pattern; and, based on the image data of the modified inspection frame pattern, modified inspection frame pattern forming means for forming a modified inspection frame pattern; and A circuit board appearance inspection apparatus, comprising: an inspection unit that performs an appearance inspection of the semiconductor circuit board to be inspected. 4. The circuit board appearance inspection apparatus according to claim 3, wherein the reference pattern data detecting means detects image data of the reference pattern based on an infrared image of the reference pattern.