JPH0743382A - Offset correction method for each arm position in XY type circuit board inspection apparatus - Google Patents

Abstract

(57) [Summary] [Purpose] Minimize the variation in positioning between arms regardless of the distance from the origin. [Structure] A digitizer D capable of detecting the coordinates of a probing point is provided, and after aligning each arm of L, M, and R with respect to the origin, the same probing data is given to each arm and a working area is provided from the origin position. After probing on the digitizer D so as to make one round, obtain the probing point coordinates of a specific arm from the digitizer D as target point data, and the probing point coordinates of other arms as comparison point data,
From the deviation of the comparison point data with respect to the target point data, X
Maximum value of deviation in + direction + maximum value of deviation in + X and + ΔY and-direction in each of the axial direction and the Y-axis direction-
The maximum deviation width WX (= | + ΔX | + | −ΔX |) is detected in each of the X-axis direction and the Y-axis direction by detecting ΔX and −ΔY.
And WY (= | + ΔY | + | −ΔY |) are obtained, and each coordinate data is corrected using the median values WX / 2 and WY / 2 as correction values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to each arm for holding a probe pin in an XY type circuit board inspection device,
The present invention relates to an offset correction method when performing the alignment.

[0002]

2. Description of the Related Art Generally, in an XY type circuit board inspection apparatus, three arms of a left (L), a middle (M) and a right (R) are arbitrarily moved along the X-axis direction and the Y-axis direction. It is provided to get. In the following description, these arms will be referred to as L arm, M arm, and R arm.

Actually, a probe pin is attached to each of these arms for measurement, but prior to that, it is necessary to align the three arms.

For this reason, conventionally, as shown in FIG. 4, a dedicated substrate A for offsetting (adjusting the origin) is set at a position serving as the origin of the working (inspection) area S, Each of the L, M, and R arms is adjusted to its origin position to correct the positional relationship between them.

[0005]

According to this, it is possible to offset each arm relatively easily, but there is a problem in terms of accuracy. That is, although the positioning accuracy near the origin is high, the error of the drive system accumulates as the distance from the origin increases, and therefore the positioning accuracy and the positional relationship between the arms apart from the origin cannot be guaranteed.

[0006]

The present invention has been made in order to solve the above-mentioned problems, and the structural features thereof are as follows.
An XY type circuit board inspecting apparatus having at least two arms capable of holding a probe pin and arbitrarily moving in the X-axis direction and the Y-axis direction is provided with a digitizer capable of detecting coordinates of a probing point, and each arm is provided with After aligning with respect to the origin, give the same probing data to each arm, and perform probing on the digitizer so that it makes one round of the working area from the origin position. As the target point data, and after obtaining the probing point coordinates of the other arm as the contrast point data, from the deviation of the contrast point data with respect to the target point data, in each of the X-axis direction and the Y-axis direction,
The maximum value + ΔX, + ΔY of the deviation in the + direction and the maximum values −ΔX, −ΔY of the deviation in the − direction are detected, and the maximum deviation width WX (= | + ΔX | +) in each of the X-axis direction and the Y-axis direction.
| −ΔX |) and WY (= | + ΔY | + | −ΔY |) are obtained, and each coordinate data is corrected using the median values WX / 2 and WY / 2 as correction values.

[0007]

As described above, the median value W of the maximum deviation widths WX and WY is as described above.
X / 2 and WY / 2 are obtained, and the coordinate data of the arm is corrected so that the target point obtained from one arm comes to the median value, so that positioning between the arms can be performed regardless of the distance from the origin. Variations are minimized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 schematically shows an XY unit portion of the XY type circuit board inspection apparatus. According to this, in the same XY unit part, L,
In order to take the offsets of the M and R arms, a digitizer D for obtaining the coordinate data of the probing point is prepared.

Each of the L, M and R arms is arbitrarily moved along the XY axis direction by a coordinate signal from a CPU (central processing unit) via an XY axis motor control means MC, and a predetermined object is moved. Probing to the measurement point. And
The coordinate data of the probing point is read by the CPU. Therefore, the CPU is provided with a memory that stores a measurement program, coordinate data of probing points, and the like.

Now referring to FIGS. 2 and 3,
Offset correction of each of the L, M, and R arms will be described. First, with respect to each of the L, M, and R arms, the origin is aligned using, for example, the dedicated substrate A described above.

Next, the same probing data is given to each of the L, M, and R arms, and probing is performed while moving the digitizer D from its origin so as to make one round of the outer circumference of the working area.

Then, the probing point coordinate data of each arm is fetched from the digitizer D into the memory of the CPU. In this example, the probing point coordinate data of the M arm is used as the reference point data and the other L, The offset correction is performed by using the probing point coordinate data by the R arm as the comparison point data.

FIG. 2 shows, for example, L with the M arm as a reference.
The case of offsetting the arm is illustrated. That is, in the figure, the target point data obtained by the M arm is shown by a solid line in the shape of a rectangular frame, whereas L
The contrast point data obtained by the arm are indicated by circles.

The CPU compares these data and, from the deviation of the comparison point data with respect to the target point data, the maximum value of the deviation in the + direction in each of the X-axis direction and the Y-axis direction + ΔX, + ΔY and − direction. Maximum deviation of −ΔX,
Detect ΔY (see FIG. 3).

The maximum deviation width WX (= | + ΔX | + | −ΔX |) in each of the X-axis direction and the Y-axis direction.
And WY (= | + ΔY | + | −ΔY |) are obtained, and the coordinate values of the L arm are corrected using the median values WX / 2 and WY / 2 as correction values.

That is, this median value (WX / 2, WY /
The coordinate data of the L arm is subtracted by the same median value so that the difference between the coordinates of 2) and the target point data becomes "0". This means that, relative to each other, as shown by the arrow in FIG. 2, the target point data (target point coordinates) of the M arm as the reference is corrected to the center of the shift width region of the L arm indicated by the diagonal line. Means Similarly, the R arm is also offset based on the M arm.

Therefore, it can be expressed that any position of the test point falls within an error of ±% of the target position. Further, by taking the offset in this way, it becomes possible to reduce the deviation width when each arm probes the same coordinates.

Although the L arm and the R arm are offset with respect to the M arm in the above embodiment, the L arm or the R arm may be used as a reference depending on the case.

In obtaining the coordinates of the probing points of the respective arms from the digitizer D, in the above embodiment, the probing point coordinates of the M arm are first obtained, and then the probing point coordinates of the L arm and the R arm are obtained. I am trying to get it.

[0020]

As described above, according to the present invention, the probing point coordinates of each arm are obtained by the digitizer in the XY type circuit board inspection apparatus.
By offsetting the other arm based on the probing point coordinates of a specific arm, it is possible to minimize the variation in positioning between the arms regardless of the distance from the origin.

[Brief description of drawings]

FIG. 1 is a schematic diagram schematically showing an XY unit portion in an XY type circuit board inspection device applied to the present invention.

FIG. 2 is an explanatory view showing an example in which an offset is applied to another arm based on a specific arm according to the present invention.

FIG. 3 is an explanatory diagram showing a relationship between target point data and a median value in the description of FIG.

FIG. 4 is an explanatory diagram for explaining a conventional arm offset method.

[Explanation of symbols]

 L, M, R Arm for holding probe pin D Digitizer MC XY axis motor control means CPU Central processing unit

Claims (1)

[Claims] 1. A digitizer capable of detecting the coordinates of a probing point in an XY type circuit board inspection device having at least two arms which hold a probe pin and can arbitrarily move in the X-axis direction and the Y-axis direction. After each arm is aligned with the origin, the same probing data is given to each arm, and each arm is probed so that it makes one round of the working area from the origin position. After obtaining the probing point coordinates of No. 2 as the target point data and the probing point coordinates of the other arm as the comparison point data, the X axis direction and the Y axis direction are selected from the deviations of the comparison point data with respect to the target point data. Maximum deviation of + direction in each direction + ΔX, + ΔY
The maximum deviations WAX in the X-axis direction and the Y-axis direction are detected by detecting the maximum values -ΔX and -ΔY of the deviations in the and-directions.
(= | + ΔX | + | −ΔX |) and WY (= | + ΔY | +
| −ΔY |) and the median value WX / 2, WY / 2
Is used as a correction value to correct each coordinate data, and an offset correction method for each arm position in the XY type circuit board inspection apparatus.