JPH04225173A - Device for inspecting circuit board - Google Patents

Abstract

PURPOSE:To make teaching a measuring point in an inspection device for a circuit board of X-Y type in a short time. CONSTITUTION:The CCD camera 11 moving with a probe 2 to take a picture of that measuring point P previously fixed and the image processing element 13 converting image data output from the same CCD camera 11 into digital data of binary level to develop on a coordinate system on picture element arranged in a matrix state, are provided. A CPU 14 controls a probe moving measure so that the position of centroid of the measuring point P agrees with the specifying point on the coordinate system on picture element, while the CPU 14 finds the position of centroid of the measuring point P from the number of picture elements corresponding to the shape of the measuring point P on the coordinate system on picture element and from several coordinate values which those have.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-Y type circuit board inspection device, and more specifically, to teaching of measurement points.

0002

2. Description of the Related Art In an XY type circuit board inspection apparatus having at least two movable probes, it is necessary to teach measurement points and obtain coordinate data thereof prior to actual measurement.

[0003] Taking FIG. 3 as an example, reference numeral 1 denotes a moving head having a probe 2 . The movable head 1 reciprocates along a guide arm 3 oriented in the X direction, and the guide arm 3 itself reciprocates along a guide rail (not shown) oriented in the Y direction. , move to any position on the circuit board A.

The movable head 1 is provided with a laser light source 4 for teaching the measurement point P. That is, while referring to the laser beam of the laser light source 4, the probe 2 is moved to the desired position (measurement point P) using the X and Y movement keys. Then, actually lower the probe 2 and check whether the position is correct.

[0005]

[Problem to be Solved by the Invention] However, if it is not correct, this process must be repeated by trial and error, which takes a considerable amount of time.

[0006]

[Means for Solving the Problems] This invention has been made in view of the above-mentioned conventional circumstances, and its structural features are
at least two probes that are movable in different directions; a measurement section that includes a measurement signal generation section and a signal measurement section that are connected to the probes; a probe movement means that moves the probes; In the circuit board inspection apparatus, the circuit board inspection apparatus includes a control means such as a CPU that controls a probe moving means, a CCD camera that moves together with the probe and images a predetermined measurement point of the probe, and the CCD camera. an image processing unit that converts the image data outputted from the image data into digital data at a binary level and develops it on a pixel coordinate system arranged in a matrix, the control means converts the image data output from the The center of gravity position of the measurement point is determined from the number of pixels corresponding to the shape of the measurement point and their respective coordinate values, and the probe moving means is moved so that the center of gravity position coincides with a specific point on the pixel coordinate system. The reason lies in the fact that it is controlled.

[0007]

[Operation] According to the above configuration, the image of the measurement point is converted into digital data at a binary level and developed on a pixel coordinate system arranged in a matrix.

The control means (CPU) determines the position of the center of gravity from this image data, and controls the probe moving means so that the position of the center of gravity coincides with a specific point, for example, the center point, on the pixel coordinate system.

[0009] This allows the probe to come into contact with each measurement point under the same conditions in a relative sense, thereby increasing the reliability of the measurement.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, according to the present invention, a movable head 1 is equipped with a CC
A D camera 11 is attached. In connection with this, a CRT 12 as a display device and an image processing section 13 are provided.

Note that 14 is a CPU as a control means;
5 is a measurement unit including a measurement signal generation unit and a signal measurement unit that are connected to the pair of probes 2, 2; 16 is a control unit that controls the servo drive system of the probe 2; and 17 is a memory in which inspection programs and the like are written. be.

Reference numeral 18 is a keyboard for giving commands to the CPU 14.
In addition to a cursor key 18a for instructing movement in the -Y direction, an up key 18b for moving the probe 2 up, and a down key 18c for moving the probe 2 down, a center of gravity movement key 19 is provided.

[0013] To teach the measurement point P,
The moving head 1 is moved so that the measurement point P can be captured by the CCD camera 11 by operating the cursor key 18a. As a result, the image of the measurement point P is displayed on the CRT 12, and the image signal is written into the memory of the image processing section 13 as image data.

[0014] This image data is converted into black and white binary level digital data using a predetermined threshold value, and is developed on a pixel coordinate system 13a arranged in a matrix as shown in FIG. .

In this embodiment, the pixels in the area corresponding to the shape of the measurement point P are treated as black data, and the center of gravity position is determined by the CPU based on the number of pixels and their respective coordinate values.
14.

That is, the coordinates of the center of gravity are (x, y),
The total number of pixels of black data is n, and the coordinates of each black data are (Xn,
Yn), it is expressed by (x, y)=Σ(Xn, Yn)/n.

After the center of gravity position (x, y) of the measurement point P has been determined in this way, when the center of gravity movement key 19 of the keyboard 18 is pressed, the CPU 14 calculates the center of gravity position (x, y) of the measurement point P.
, y) are located at, for example, the center point of the pixel coordinate system 13a.

Then, press the down key 18c to actually lower the probe 2 and check it on the CRT 12. By performing this for all measurement points, the coordinate data can be obtained.

In the above embodiment, when the center of gravity movement key 19 is pressed, the movable head 1 is moved so that the center of gravity position (x, y) moves to the center point of the pixel coordinate system 13a.
It does not necessarily have to be the central point. That is, this may be any specific point, and in short, the center of gravity of all measurement points may be moved to the specific point.

Furthermore, on the pixel coordinate system 13a, the pixels in the pattern of the measurement point P are assumed to be black data, but it goes without saying that this may be reversed and recognized as white data to calculate its center of gravity. .

[0021]

As described above, according to the present invention, the time required for teaching measurement points can be significantly shortened without repeating trial and error as in the prior art.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining one embodiment of the present invention.

FIG. 2 is a diagram showing a pixel coordinate system within the image processing unit in the same embodiment.

FIG. 3 is a schematic diagram for explaining a conventional example.

[Explanation of symbols]

1. Moving head 2 Probe 11 CCD camera 12 CRT 13 Image processing section 14 Control means (CPU) 15 Measurement part 16 Servo system control section 17 Memory 18 Keyboard 19 Center of gravity movement key

Claims (1)

[Claims] 1. At least two probes movable in the X-Y directions; a measurement section connected to the probes and including a measurement signal generation section and a signal measurement section; and probe movement means for moving the probes. A CCD camera that moves together with the probe and images a predetermined measurement point of the probe in a circuit board inspection apparatus comprising a control means for controlling the measurement section and the probe moving means based on a predetermined program. and an image processing unit that converts the image data output from the CCD camera into digital data at a binary level and develops it on a pixel coordinate system arranged in a matrix, and the control means Determine the center of gravity position of the measurement point from the number of pixels corresponding to the shape of the measurement point on the coordinate system and their individual coordinate values, and make sure that the center of gravity position coincides with a specific point on the pixel coordinate system. A circuit board inspection device characterized by controlling the probe moving means.