JP2570650B2 - Substrate inspection device and substrate inspection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a board inspection apparatus and a board inspection method for inspecting a printed board by taking an image of the printed board with a TV camera.

[0002]

2. Description of the Related Art Conventionally, a board inspection apparatus and a board inspection method of this kind take an image of an entire printed board to be inspected at a predetermined fixed magnification, and A / D convert an image signal to obtain characteristic parameters of each board-shaped component. The pattern to be inspected is extracted and compared with a reference pattern (reference characteristic parameter) to check whether the component is mounted at a correct position on the board.

[0003]

However, in the conventional apparatus and method, in order to judge by imaging at a fixed magnification, for example, details such as an area where chip components are densely mounted on a substrate are determined. There is a problem that determination is difficult.

On the other hand, in order to determine the above details, it is necessary to take an image of the substrate at a high magnification. In this case, it takes time to determine the entire area of the substrate, and it is not practical in an actual component mounting line. There is a problem that there is no.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a board inspection apparatus and a board inspection method capable of inspecting details of a printed circuit board to be inspected in a short time.

[0006]

Means for Solving the Problems In order to solve the above problems, a board inspection apparatus according to the present invention processes image data obtained by capturing an image of a board to be inspected on which components are mounted, and processes the image data.
In a board inspection apparatus for inspecting a mounting state of components on a board to be inspected, an imaging unit capable of selecting different imaging magnifications, and an extraction unit for extracting a predetermined imaging area on the inspected board for each same imaging magnification. And control means for controlling the imaging so as to image the predetermined imaging area extracted for the same imaging magnification by the extraction means.

Further, the board inspection method of the present invention includes an image pickup means capable of selecting a plurality of different image pickup magnifications, and divides a substrate to be inspected into a plurality of image pickup areas for each of the image pickup magnifications in advance.
The imaging areas are divided into groups for the same magnification, imaging magnifications suitable for these groups are stored, and a predetermined imaging area stored for the same imaging magnification stored in advance by the imaging unit is sequentially imaged. The mounting state of the mounted component is inspected based on the image data obtained by the imaging.

[0008]

According to the present invention, when inspecting the mounting state of components on a substrate to be inspected by processing image data obtained by imaging the substrate to be inspected on which the components are mounted, the imaging areas at the same imaging magnification are combined. The image is inspected.

Further, according to the present invention, when an image of an imaging area at the same imaging magnification is taken, at least the coordinates of the part and the identification information of the part among the reference feature parameters are used from the part mounting data in the part mounting step. When the magnification is divided into groups, there is no need to perform grouping while looking at the substrate to be inspected.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A substrate inspection apparatus and a substrate inspection method according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of a substrate inspection apparatus according to the present invention.

This apparatus has a TV camera 1 which is an image pickup means for picking up an image of a printed board P which is a board to be inspected on which a chip component C is mounted. The TV camera 1 has a zooming mechanism and an autofocus mechanism. A plurality of imaging magnifications can be selected. Note that the TV camera 1 may be a color TV camera or a black and white TV camera.

The present apparatus also includes an XY stage 2 for mounting and fixing the printed circuit board P and moving it in the XY directions, a processing unit 3 to be described later, and each component C serving as a reference when inspecting the printed circuit board P. Input reference data composed of characteristic parameters such as an identification number, coordinates, area, shape, and center of gravity, and, as shown in FIG. 2, for each imaging magnification (A, 3A, 5A) of the TV camera 1 (X ₁ , y ₂ ) to (x _n , y) which are position information of the imaging area of the printed circuit board P
_n ) and position coordinates for focusing at each magnification (described later)
And an input unit 4 for inputting each processing procedure, and an output unit 5 for outputting test results and input data such as a printer and a CRT display.

The above-described processing unit 3 performs A / D conversion of a central processing unit (CPU) 3a as a control means and an image signal of each component C on the printed circuit board P captured by the TV camera 1, and converts each component into a digital signal. Image processing unit 3 for extracting characteristic belly meter of C
b.

In addition, instead of inputting the reference data for inspecting the printed circuit board P through the input unit 4 as described above, a reference substrate is previously mounted on the XY stage 2 and each data is output by the image processing unit 3b. The reference characteristic parameters of the component C may be extracted and input. Further, as the reference feature parameter, component mounting data of a mounting device used in a component mounting process before the main inspection process may be used.

The processing unit 3 also includes a data memory 3c and a CP.
Program memory 3 storing the execution program of U3a
and a drive control unit for the XY stage 2 (not shown). In the data memory 3c, the above-mentioned reference feature parameters and, as shown in FIG. 2, the position of the imaging area which is a predetermined area of the substrate P for each imaging magnification (A, 3A, 5A) of the TV camera 1 Information is stored in advance. That is, the data memory 3c plays a role as an imaging magnification information storage unit that stores the imaging magnification of the TV camera 1 and the position information of the imaging area (collectively referred to as imaging magnification information).

The imaging area for each imaging magnification in FIG. 2 will be described with reference to FIG. 3, and the substrate inspection method of the present invention will be described. First, in FIG. 3 (a), the illustrated arrows indicate an imaging direction by a so-called raster scan method in which the TV camera 1 sequentially captures an image on the printed circuit board P. In practice, the TV camera 1 is fixed and the printed circuit board P is fixed. X with
The Y stage 2 moves.

In FIG. 3, the area indicated by the solid line in the drawing is relatively loosely mounted, the area indicated by the broken line in the drawing is mounted relatively densely, and the area indicated by the dotted line in the drawing is most densely mounted. As shown in FIG. 2B, _first , the TV camera 1 is zoomed by A times at the nearest focusing mark f1 and focused, and a relatively coarse area is imaged. 3A the TV camera 1 then with focusing mark f ₂ of the nearest post A times imaging as shown in FIG. 3 (c)
It zooms in and focuses twice, and images a relatively dense area. Similarly, focusing while zooming the TV camera 1 to 5A times most near the focusing mark f ₃ after 3A doubled imaging, imaging the densest area.

In the focusing method of the TV camera, a plurality of focusing marks (f _{1 to} f ₂ ) may be provided on the printed circuit board P. Is also good. The magnification is A, 3A
It is needless to say that the magnification is not limited to the magnification of 5A and may be other magnifications.

Therefore, as described above, A-time zooming and in-focus imaging, 3A-time zooming and in-focus imaging, and 5A
In the case of performing double zooming and imaging after focusing, as shown in FIG. 2, an imaging area of A times, an imaging area of 3A times, and 5A
The double imaging area is previously stored in the data memory 3 via the input unit 4.
Stored in c. The coordinate in the second view (x _1, y ₂₎
~ (X _n, y _n) represents the center of the field of view of the TV camera 1 on the printed circuit board P, the TV camera 1 by the coordinate
Are specified. Fig. 3 (c)
In the case of imaging at the magnification in (d), the imaging area is smaller than the A-times imaging area in FIG. 3 (a), so that the entire area is imaged.

FIG. 4 is a flowchart for explaining the schematic operation of the CPU 3a of the processing unit 3. First, in steps (hereinafter referred to as ST) 1 and 2, respectively, a data memory 3c as shown in FIG. The set magnification is read, and the area (coordinates) of each magnification is extracted.

Next, the magnification (A) read in ST3
Is determined to be equal to the currently set magnification of the TV camera 1, and if not, the process branches to ST4.
In ST4, as shown in FIG.
The by imaging a moving TV camera 1 a printed board P of the focusing mark f ₁ (or the first wiring pattern and parts of the imaging area of the magnification) and zooming the magnification (A times), also in the subsequent ST5 Perform focusing.

When the focusing is completed in ST5, the process proceeds to ST6, and the area of the magnification (A times) is sequentially set on the TV.
An image signal is captured by the camera 1, and the image processing unit 3b extracts the characteristic parameters of each component after A / D conversion of the image signal, and stores the extracted characteristic parameters in the data memory 3c.

In ST7, it is determined whether or not imaging of the entire area of the printed circuit board P has been completed. If NO, the process returns to ST3 to perform processing for a new magnification (3A). Hereinafter, zooming (ST4) and focusing (ST5) are performed for each magnification, and imaging (the broken line in FIG. 3 (c) and the dotted line in FIG. 3 (d)) at the magnification are performed.
Data (feature parameters) of the component C in the entire area of the board P is obtained.

As described above, when the characteristic parameters are extracted for all the parts C on the printed circuit board P, the process proceeds from ST7 to S.
Proceeding to T8, the comparison is made with the reference parameter of each component C stored in the data memory 3c in advance, and if there is an instruction from the input unit 4 in the subsequent ST9, the inspection result is output via the output unit 5.

[0025]

As described above, according to the present invention, the imaging areas at the same imaging magnification are collectively imaged and inspected.
Each time the imaging area is changed, the operation of setting the magnification is not required, and the mounting state of the component can be inspected in a short time and efficiently to the details of the substrate to be inspected.

Further, according to the present invention, when imaging an imaging area with the same imaging magnification, at least the coordinates of the component and the identification information of the component among the reference feature parameters are used from the component mounting data in the component mounting process. Therefore, at the time of grouping the imaging magnification, at least the coordinates of the component and the component identification information among the reference parameters can be easily used as the criterion for the grouping without performing the grouping while looking at the substrate to be inspected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a substrate inspection apparatus according to the present invention.

FIG. 2 is an explanatory diagram of main part storage contents of a data memory in FIG. 1;

FIG. 3 is an explanatory diagram showing an imaging procedure of the apparatus in FIG. 1;

FIG. 4 is a flowchart for explaining a schematic operation of a CPU in FIG. 2;

[Explanation of symbols]

 Reference Signs List 1 TV camera (imaging means) 3a Central processing unit (CPU) (control means) 3b Processing section (extraction means) 3c Data memory (imaging magnification information storage means) P Printed board (substrate to be inspected)

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshio Tateishi 10 Tatemachi, Hanazono-cho, Ukyo-ku, Kyoto-shi, Tateishi Electric Co., Ltd. (56) References JP-A-61-241605

Claims (2)

(57) [Claims] 1. A board inspection apparatus that processes image data obtained by imaging a board to be inspected on which components are mounted and inspects a mounting state of the components on the board to be inspected, wherein different imaging magnifications can be selected. Imaging means, and a predetermined imaging area on the substrate to be inspected, based on component mounting data of a component mounting step, based on at least component coordinates and component identification information among reference feature parameters of each component mounted on the substrate to be inspected. Extracting means for extracting the same image pickup magnification for each of the same image pickup magnifications, and control means for controlling the image pickup apparatus to take an image of the predetermined image pickup area extracted for the same image pickup magnification by the extractor. Board inspection equipment. 2. A board inspection method for inspecting a mounting state of components on an inspection board by processing image data obtained by imaging a board to be inspected on which components are mounted, wherein a plurality of different imaging magnifications can be selected. The imaging substrate is divided into a plurality of imaging areas in advance for each of the imaging magnifications, and the imaging area is defined as at least one of the reference feature parameters of the components mounted on the inspection substrate in advance. Coordinates and component identification information are used on the basis of component mounting data in the component mounting process, grouped for each same magnification, and imaging magnifications suitable for each group are stored and stored by the imaging means. Sequentially imaging a predetermined imaging area stored for the same imaging magnification, and inspecting a mounting state of a mounted component based on image data obtained by the imaging; Substrate inspection method according to claim.