JPH0915302A - Method and device for positioning circuit board inspection device - Google Patents

Abstract

PURPOSE: To precisely position at high speed with a single compensation by rotating a fixture fixing a probe pin group. CONSTITUTION: A circuit board 54, acting as an inspection object and fixed on an inspection table 11, is, based on an instruction from a computer 23, moved by an X/Y table, so that image recognizing two points patterns 55 and 56 of the substrate 54 are introduced into a field of view of a CCD camera 16. The patterns 55 and 56 are made into pictures by the camera 16, and converted into a binary image by an image processor device 22, and respective centroid coordinate positions 43 and 44 are stored (23). Then the table 20 is moved by deviation amount between a middle point 45, of the coordinates 43 and 44, and a middle point 48, of two reference position coordinates 46 and 47 set in advance, so as to coincide the points 45 and 48. Then, by the angle formed by both straight lines linking the coordinates 43 and 44, and the coordinates 46 and 47 respectively, a fixture consisting of a probe pin group 14 and a holding member 15 is rotated (17), for positioning a probe point. Thus the coordinate of the table 11 does not vary, with no feedback control required, so that precise positioning is enabled at high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device and a positioning method for a circuit board inspection machine for testing the electrical characteristics of a circuit board.

[0002]

2. Description of the Related Art As a technique relating to the positioning of a circuit board inspection machine, there is JP-A-2-1576. FIG. 9 shows the configuration of the conventional technique. The positioning technique of the circuit board inspection machine disclosed in Japanese Patent Laid-Open No. 215776/1989 includes image pickup means 6A, 6B for positioning the circuit board 8 and drive means 10A, 10B, 10C on the inspection table 2 on which the circuit board 8 is mounted. The position information of the circuit board 8 obtained by the image pickup means 6A and 6B is learned, and the image is stored as a reference image.
Until the image obtained by 6B approaches the reference image, the inspection table 2 is driven by the driving means 10C in the X direction and the driving means 10A.
Further, the driving means 10B is moved in the Y direction, and the driving ratio of the driving means 10A, the driving means 10B, and the driving means 10C is moved in the θ direction to perform accurate positioning.

Further, the deviation amount between the position information obtained by the image pickup means and the reference position taught in advance is calculated, and the inspection table on which the circuit board is mounted is moved by the deviation amount as in the above-mentioned prior art. There is known a positioning technique of moving by a driving means.

[0004]

However, in the above-mentioned conventional technique, the θ direction drive and the X and Y direction drive are performed by the difference in the drive amounts of the three motors 10A, 10B, and 10C. When the drive means in the θ direction is moved,
Along with this, the coordinates in the X and Y directions change, and accurate positioning cannot be performed with a single position correction. Therefore, in order to perform accurate positioning, it is necessary to perform feedback control of these driving means and the position of the inspection table, which requires complicated correction calculation and has a drawback that positioning takes time. .

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a positioning device and a positioning method for a circuit board inspecting machine which can easily and quickly position a probe point of the circuit board inspecting machine. The purpose is to

[0006]

Means for Solving the Problems In order to solve the above problems, the present invention is configured as follows. According to a first aspect of the present invention, in a positioning device for a circuit board inspection machine having a two-point pattern for positioning, an inspection stand for fixing a circuit board to be inspected, a drive mechanism for moving the inspection stand,
An image pickup device for visualizing a positioning pattern on a circuit board, an image processing device for processing and storing the output from the image pickup device as binary pixel information, a fixture including an inspection probe pin group and a holding member thereof. A rotation drive mechanism for moving the lens in a rotation direction, a fixture in which a rotation center of the rotation drive mechanism is aligned with a midpoint of two positioning patterns on the circuit board, and a position obtained by the image processing apparatus. Based on information, the inspection table drive mechanism and the rotation drive mechanism are configured to calculate a correction movement amount and control means for controlling the correction movement.

According to a second aspect of the present invention, two points of an image recognition probe on the circuit board to be inspected, a part, a mark such as a part of the pattern are recognized by the image pickup means and the image processing device, and are measured in advance. In the positioning method of the circuit board inspection machine, the position where the probe pin group abuts on the probe is corrected in the three-dimensional directions of X, Y, and θ based on the deviation amount from the reference mark recognition position. A first process of visualizing the above two marks, a second process of storing the two video signals in the first process as binary image information of the two processes, and two processes in the second process. Teaching in advance the third process of calculating the respective barycentric positions from the binary image information of 3 and storing as the actual position information of the two points, and the midpoint of the coordinate positions of the two points obtained in the third process. The center point of these two reference coordinates And a straight line connecting the coordinates of the two points moved in the fourth step and a straight line connecting the reference coordinates of the two points. And a fifth step of controlling the rotary drive mechanism of the fixture according to the first aspect.

[0008]

According to the present invention, the midpoint of the position coordinates of the image recognition points of the two points which are image-recognized by the image pickup means, and the reference coordinates of the two image recognition points. X, the amount of deviation from the coordinate of the center of rotation
The inspection table is moved in the Y direction, and the probe pin group is fixed instead of the inspection table by the inclination of the position coordinates of the two image recognition points that have been image-recognized and the image recognition points of these two points. Rotate the fixture you are doing. That is, the X- and Y-direction drive mechanisms of the inspection table are separated from the θ-direction drive mechanism, and even if the θ position is corrected, the X- and Y-direction coordinates of the inspection table may change. Since there is no need for feedback control of the drive mechanism and the position, high-speed and accurate positioning can be performed with only one position correction.

[0009]

【Example】

[Embodiment 1] Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram showing a positioning device of a circuit board inspecting machine of this embodiment, FIG. 2 is a diagram showing a part of a probe pin group which is a contact pin for inspection provided in the device of this embodiment as seen from below, and FIG. Is a perspective view showing an XY table provided in the apparatus of the present embodiment, FIGS. 4 and 5 are diagrams showing a relationship between barycentric position coordinates and reference position coordinates, and FIG. 6 is a perspective view showing a circuit board to be inspected. Is.

As shown in FIG. 8, the inspection target substrate 54 is
It has two image recognition patterns 55 and 56 for positioning, and it is premised that the two patterns 55 and 56 are arranged as far apart as possible in order to improve the positioning accuracy.

In FIG. 1, 17 is a probe pin group 14
It is fixed to the upper surface of the upper wall of the support body 21 by a motor that rotates a fixture composed of the holding member 15 and the holding member 15.
The shaft 18 of the rotation motor 17 is arranged so as to penetrate the upper wall of the support body 21, and the probe pin group 1 is provided at the tip thereof.
4 holding members 15 are connected.

As shown in FIG. 2, the probe pin group 14 includes a probe pin 30 contacting a first point 55 of an image recognition pattern and a probe pin 31 contacting a second point 56 of an image recognition pattern. Midpoint 32 of straight line 33
Is held by the holding member 15 with its tip facing downward so that it coincides with the rotation center 19 of the rotation motor 17 of the fixture in FIG.

Reference numeral 16 is a pattern 55, 56 for image recognition.
Is a CCD camera for visualizing the image of, and is fixed to the lower surface of the upper wall of the support 21. The CCD camera 16 has C
An image processing device 22 for extracting a video signal captured by a CD16 camera as a binary signal is connected.

Below the probe pin group 14 and the CCD camera 16, an XY table 20 provided on the upper surface of the lower wall of the support 21 is arranged. The inspection table 11 is placed on the XY table 20, and the circuit board 54 to be inspected is placed from the direction of the arrow 12 by a transport mechanism (not shown).

A computer 23 is connected to the rotary motor 17, the XY table 20 and the image processing device 22. The computer 23 recognizes an image from a binary signal obtained by the image processing device 22. Pattern 5 for
The position information of 5, 56 and the correction movement amount are calculated, and the correction movement of the motor 17 for rotating the fixture and the XY table 20 is controlled.

FIG. 3 shows a detailed view of the XY table 20 and the inspection table 11. 20b is an X-axis table provided with the inspection table 11, and the inspection table 11 can be moved in the X direction 42 by an X-axis motor 40b. 2
Reference numeral 0a denotes a Y-axis table fixed to the upper surface of the upper wall of the support body 21, which is provided with an X-axis table 20b. The Y-axis motor 40a can move the X table 20b and the inspection table 11 in the Y direction 41. Has become.

Next, a procedure for positioning the circuit board by the positioning device of this embodiment will be described. In FIG. 1, the circuit board 54 to be inspected is conveyed in the direction of arrow 12 on a guide groove (not shown) by a conveying device (not shown), and is fixed on the inspection table 11 by a fixing mechanism (not shown).

Before positioning the circuit board 54,
A circuit board to be a master is placed on the inspection table 11 by the transfer mechanism and the fixing mechanism, and the patterns 55 and 56 for image recognition of the master circuit board are at the center of the visual field of the CCD camera 16 of the XY table 20. Each coordinate is taught. Hereinafter, these coordinates will be referred to as pre-instructed reference position coordinates, which are indicated by 46 and 47 in FIG. At the reference position coordinates 46 and 47, the pattern 55 and the probe pin 30 and the pattern 56 and the probe pin 31 are in contact with each other, and the midpoint 48 of the reference position coordinates 46 and 47 is the rotation motor 1.
It coincides with the center of rotation 19 of 7.

As shown in FIG. 6, the fixed circuit board 54 to be inspected has two patterns 55 and 56 for image recognition.
And a computer 23 is placed at a position taught in advance so that the first point 55 of them is in the field of view of the CCD camera 16.
It is moved by the XY table 20 that has received the command (see FIG. 4). Then, the CCD camera 16 visualizes this pattern 55, and the image processing device 22
It is converted into a binary image, and its barycentric position coordinate 43 is stored in the computer 23.

Next, another pattern 5 for image recognition is used.
6 is moved by the XY table 20 instructed by the computer 23 to a position taught in advance so that the CCD 6 is within the field of view of the CCD camera 16. And CCD camera 1
6, the image recognition pattern 56 is visualized, converted into a binary image by the image processing device 22, and the barycentric position coordinates 43 and 44 thereof are stored in the computer 23.

Next, the barycentric position coordinates 43, 44 of these two points
Midpoint 45, and the midpoint 4 of two reference position coordinates 46, 47 taught in advance based on the master circuit board.
The XY table 20 is moved by the amount of deviation from 8, that is, ΔX and ΔY.

As a result, as shown in FIG.
Midpoint 45 of the patterns 55 and 56 for image recognition of the above two points
And the reference position coordinates 4 of these two points
The midpoint 48 of 3, 44 coincides, and next, the straight line 49 connecting the center-of-gravity position coordinates 43, 44 and the reference position coordinate 4
It suffices to rotate the fixture by the rotation motor 17 by an angle θ formed by the straight line 50 connecting 6 and 47.

In this embodiment, the shaft 18 of the turning motor 17 and the holding member 15 are directly connected to each other. However, the rotation speed of the turning motor 17 is reduced by the worm gear to hold the holding member 15. By making it rotate, the accuracy of rotation can be further improved.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIGS. 7 and 8. FIG. 7 is a block diagram showing the positioning device of the circuit board inspection machine of this embodiment, and FIG. 8 is a diagram showing the relationship between the barycentric position coordinates and the reference position coordinates. This embodiment is different from the first embodiment only in that two CCD cameras are provided, and this point will be described.

In this embodiment, 16a is a first CCD camera for visualizing the first pattern 55 for image recognition, and 16b is a second pattern 5 for image recognition.
6 is a second CCD camera for visualizing 6. 1st C
The CD camera 16a and the second CCD camera 16b have the same positional relationship as the positional relationship between the two-point patterns 55 and 56 on the circuit board, and the two-point patterns 55 and 56 correspond to the first CC.
It is fixed to the lower surface of the upper wall of the support 21 at a position where it is simultaneously imaged by the D camera 16a or the second CCD camera 16b.

Next, a procedure for positioning the circuit board by the positioning apparatus of this embodiment will be described. Example 1
The circuit board 54 fixed to the inspection table 11 in the same manner as
The two patterns for image recognition 55 and 56 for image recognition are moved by the XY table 20 instructed by the computer 23 to a pre-instructed position so that the patterns 55 and 56 for image recognition come within the visual fields of the first CCD camera 16a and the second CCD camera 16b. It Then, the first CCD camera 16a and the second CCD camera 1
6b visualizes these two-point patterns 55, 56, and the image processing device 22 produces two-point patterns 55, 5
6 is converted into a binary image, and the respective barycentric position coordinates are stored in the computer 23.

FIG. 8 is a diagram showing the relationship between the barycentric position coordinates obtained by image recognition of the two-point patterns 55 and 56 and the respective reference position coordinates. FIG.
5 and FIG. 8B are based on the pattern 56. FIG.
In the X- and Y-direction average values of the amounts of deviation between the barycentric position coordinates 50 and 51 of the two points and the reference position coordinates 52 and 53 of the two points taught beforehand based on the master circuit board, respectively. Certain ΔX3 and ΔY3 (see Formula 1 and Formula 2) are obtained, and the XY table 20 is moved by the amount of ΔX3 and ΔY3. Here, ΔX3 and ΔY3 are obtained by image-recognizing the barycentric position coordinate 50 and the reference position coordinate 52 and the barycentric position coordinate 50 and the reference position 53, and the differences from the calculated barycentric position are ΔX1, ΔY1 and ΔX2, ΔY2, respectively. , ΔX3 = (ΔX1 + ΔX2) / 2 ... Equation 1 ΔY3 = (ΔY1 + ΔY2) / 2 ...

As a result, as in the first embodiment, the coordinates in the X and Y directions are matched, and then the reference position coordinates 5
It is only necessary to rotate the fixture by the rotation motor 17 by an angle formed by the straight line connecting 2, 53 and the straight line connecting the center-of-gravity position coordinates 50, 51.

According to the present embodiment, in addition to the effects of the first embodiment, the image can be captured at two points without the movement of the coordinates, so that the positioning can be performed at high speed.

[0030]

According to the present invention, the positioning of the probe points of the circuit board tester can be realized quickly and easily without feedback control.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a positioning device of a circuit board inspection machine according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a part of a probe pin group, which is a contact pin for inspection provided in the positioning device of the circuit board inspection machine according to the first embodiment of the present invention, as seen from below.

FIG. 3 is a perspective view showing an XY table provided in the positioning device of the circuit board inspection machine according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between barycentric position coordinates and reference position coordinates in the positioning method for the circuit board inspection machine according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between barycentric position coordinates and reference position coordinates in the positioning method for the circuit board inspection machine according to the first embodiment of the present invention.

FIG. 6 is a perspective view showing a circuit board to be inspected.

FIG. 7 is a configuration diagram showing a positioning device of a circuit board inspection machine according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a relationship between barycentric position coordinates and reference position coordinates in a positioning method for a circuit board inspection machine according to a second embodiment of the present invention.

FIG. 9 is a configuration diagram showing a positioning device of a conventional circuit board inspection machine.

[Explanation of symbols]

 11 Inspection table 14 Pillow pin group 15 Holding member 16 CCD camera 17 Rotating motor 20 XY table 22 Image processing device 23 Computer 43,44,50,51 Center of gravity position coordinate 45,48 Midpoint 46,47,52,53 Reference Position coordinates 54 Inspection target board 55, 56 Image recognition pattern

Claims (2)

[Claims] 1. A positioning device for a circuit board inspection machine having a positioning two-point pattern, an inspection stand for fixing a circuit board to be inspected, a drive mechanism for moving the inspection stand, and a circuit board on the circuit board. An image pickup device for visualizing a positioning pattern, an image processing device for processing and storing the output from the image pickup device as binary pixel information, and a fixture composed of a probe pin group for inspection and a holding member thereof in a rotation direction. Based on the rotation drive mechanism to be moved, the fixture in which the center of rotation of the rotation drive mechanism is aligned with the midpoint of the two positioning patterns on the circuit board, and the position information obtained by the image processing apparatus. And a control means for calculating the correction movement amount and controlling the correction movement of the inspection table drive mechanism and the rotation drive mechanism. Positioning device. 2. A reference measured in advance by recognizing positions of two image recognition probes, parts, marks of a part of a pattern, etc. on a circuit board to be inspected by an image pickup means and an image processing device. In the positioning method of the circuit board inspection machine for correcting the position where the probe pin group abuts on the probe in the three-dimensional directions of X, Y, and θ based on the amount of deviation from the mark recognition position of No. The first to visualize the mark
And the second step of storing the two-point video signals in the first step as binary image information of two points, and the two-point binary image information in the second step, the respective barycentric positions are determined. The third process of calculating and storing as the actual position information of the two points, and the reference coordinates of these two points that have been taught in advance the midpoint of the coordinate positions of the two points obtained in the third process A fourth step of controlling the drive mechanism according to claim 1 so as to match the coordinates of the middle point, a straight line connecting the coordinates of the two points moved in the fourth step, and the reference coordinates of the two points A fifth step of controlling the rotary drive mechanism of the fixture according to claim 1 by an angle formed by the connected straight line, and a positioning method of the circuit board inspection machine.