JPH11118829A - Attachment for inspection of printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently inspect a printed circuit board B in a short time. SOLUTION: An elastic mat 11, first electrodes 21, 21,... installed on the rear surface side of the mat 11, and second electrodes 22, 22,... installed on the front surface of the mat 11 are combined with each other. The first electrodes 21, 21,... are connected individually to the second ones 22, 22,... through conductor parts 23, 23,... in the mat 11, and the mat 11 is fitted closely to the pattern surface of a printed circuit board B so as to bring the electrodes 21, 21,... in contact with it. Thus the printed circuit board B can be electrically inspected through the second electrodes 22, 22,....

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board inspection attachment used for efficiently and automatically inspecting a printed circuit board.

[0002]

2. Description of the Related Art The pattern surface of a printed circuit board can be automatically inspected using a pair of contact probes.

A contact probe is constructed by slidably incorporating a contact pin into a sleeve, and the contact pin is urged toward the distal end via a spring in the sleeve. Note that an output lead wire is drawn out of the sleeve. Therefore, this is to face the pattern surface of the printed circuit board, move it to a predetermined inspection position, contact the contact pin with the pattern surface, and measure the electrical resistance between the contact probes, to obtain the pattern of the printed circuit board. The quality can be checked. In order to inspect all the patterns on the pattern surface of the printed circuit board, the contact probe inspects the entire area of the pattern surface while sequentially changing the contact position.

Further, a large number of contact probes which come into contact with all inspection positions on the pattern surface of the printed board are mounted on the pin board, and the pin board is overlaid on the printed board, so that the entire area of the pattern surface of the printed board can be seen at once. Inspection is also possible.

[0005]

According to the former technique of the prior art, the contact probe must sequentially move the pattern surface of the printed circuit board, and there is a problem that the inspection time becomes excessively long. In the latter case, it is necessary to create a pin board for each printed circuit board. In addition, when the size of the printed circuit board is large, the number of contact probes to be used increases, and a contact failure of the contact probes tends to occur. There is. Further, since the contact probe itself has a mechanically movable part, there is a problem that durability is poor and it is difficult to maintain initial performance.

Accordingly, an object of the present invention is to provide a highly reliable inspection result in a short time by providing first and second electrodes on an elastic mat in view of the problems of the prior art. It is an object of the present invention to provide a printed circuit board inspection attachment which can be suitably used for a large-sized printed circuit board.

[0007]

In order to achieve the above object, the present invention provides an elastic mat, a first electrode provided on the back side of the mat, and a second electrode provided on the front side of the mat. The gist is that the first and second electrodes are individually connected via a conductive portion in the mat.

The second electrodes can be arranged by increasing the arrangement pitch of the first electrodes.

The second electrode can be selected via a matrix circuit element, and can be arranged in accordance with the terminal arrangement of the matrix circuit element.

Further, the matrix circuit element can be mounted on a support substrate having sub-electrodes to be combined with a mat.

[0011]

According to the structure of the present invention, the mat having elasticity is brought into close contact with the pattern surface of the printed circuit board so that the first electrode on the back surface comes into contact with the pattern surface and the second electrode on the front surface is electrically connected. Electrode. Therefore, the quality of the printed circuit board can be inspected by sequentially selecting an arbitrary pair of the second electrodes and measuring the electric resistance therebetween.

When the second electrodes are arranged by increasing the arrangement pitch of the first electrodes, the second electrodes are arranged at a fine arrangement pitch at which the first electrodes can distinguish the pattern of the printed circuit board. However, by expanding it, it is possible to easily connect external wiring for measurement, an IC chip, and the like.

When the second electrode is selected via the matrix circuit element, the matrix circuit element does not individually pull out the external wiring from the second electrode, but selects a specific second electrode specified by an address signal. The electrodes are electrically drawn out to the outside, and the number of necessary external wirings can be extremely reduced. Note that a matrix circuit element refers to an IC element which can receive only an element specified by an address signal from a plurality of rows and columns of second electrodes and can be extracted to the outside when an address signal is input.

If the second electrodes are arranged in accordance with the terminal arrangement of the matrix circuit element, it is not necessary to incorporate a special dimension adjusting element between the matrix circuit element and the second electrode.

When the matrix circuit element is mounted on a support substrate with sub-electrodes, the support substrate mechanically reinforces the mat and maintains it in a plate shape, while the matrix circuit element is connected via the sub-electrode. It can be easily connected to the second electrode.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

The inspection attachment for the printed circuit board is
Are provided with a mat 11 having elasticity, first electrodes 21 provided on the back side of the mat 11, and second electrodes 22 provided on the front side of the mat 11 (FIGS. 1 and 2). ). However, the support substrate 31 is combined with the mat 11.

The mat 11 is formed in a plate shape from an elastic rubber material or plastic resin material having elasticity. Are arranged in a lattice pattern at the center of the back surface of the mat 11 at an arrangement pitch d1 that is sufficiently smaller than the minimum insulating gap W between the patterns P of the printed circuit board B to be inspected. ing. The first electrodes 21, 21... Are formed from a conductive rubber material, and the tips are formed in a dome shape and protrude toward the back surface of the mat 11.

Each of the second electrodes 22, 22...
Is formed of the same conductive rubber material as the electrode 21. The second electrodes 22, 22,... Have a dome-shaped tip protruding toward the surface of the mat 11 so that the conductive portions 2
Are individually connected to the first electrodes 21, 21,. That is, the second electrodes 22, 22,.
The first electrodes 21, 21... Electrically correspond individually. In addition, each conductive part 23 includes the first and second electrodes 2.
It may be a conductive rubber material integrated with the first and second wires 22, or a conductive wire embedded in the mat 11. The second electrodes 22, 22,... Are arranged at an arrangement pitch d2 (d2> d1) by enlarging the arrangement pitch d1 of the first electrodes 21, 21,. However, the second electrodes 22, 22,... Are arranged on the outer edge of the front surface side of the mat 11 by being divided into blocks A of a predetermined row and a predetermined column (FIGS. 3 and 4).

The support substrate 31 is formed larger than the mat 11 (FIGS. 1 and 3). A support member 34 for holding the mat 11 is attached to the back side of the support substrate 31. The center of the support member 34 is connected to the first electrodes 21 and 2,
.. Are exposed to the outside.

The supporting substrate 31 has a through hole 3 for suction at the center.
1a, 31a... Are mounted on the support substrate 31 so as to correspond to the blocks A, A,... Formed by the second electrodes 22, 22,. Each matrix circuit element 35 includes a second electrode 22 in each block A,
22 and terminals 35b, 35b... For signal input / output are formed. However, FIG. 1 shows only one terminal 35b.

The supporting substrate 31 has sub-electrodes 32, 32,.
Auxiliary electrodes 33, 33 ... are incorporated. The sub-electrode 32 and the auxiliary electrode 33 are formed as through holes penetrating the support substrate 31. The sub-electrodes 32, 32 ...
Are the second electrodes 22 in each block A on the mat 11,
22 are arranged so as to correspond to each block A.
Are connected to the corresponding terminals 35a of the matrix circuit element 35. That is, the sub-electrodes 32, 32,.
Are arranged in accordance with the terminal arrangement of the terminals 35a of the corresponding matrix circuit element 35 for each block A.

Are connected to terminals 35b, 35b of each matrix circuit element 35 through lines 31b, 31c in the support substrate 31.
Can be drawn out to the elements 36, 36. However, the control IC elements 36, 36... Are mounted on the support substrate 31, and their input / output signals are extracted to the outside via the connectors 37, 37.

Each matrix circuit element 35 has a line 31
, 31c, auxiliary electrodes 33, 33 ..., terminals 35b, 35
When control input signals such as an address signal, an output line selection signal, a reset signal, a storage signal, and a chip selection signal from the control IC element 36 are input via the control IC element 36, one or two specified by the address signal are input. Terminals 35a, 35a, second
Of the electrodes 22 and 22 are connected to another terminal 35b, 35b,
After being drawn out to the auxiliary electrodes 33, 33, the lines 31b, 31
It can be connected to the control IC element 36 via c.
However, irrespective of FIG. 1, a predetermined number of the lines 31b and 31c are arranged in parallel in the support substrate 31 in order to give necessary input / output signals to all the matrix circuit elements 35. It is assumed that

Therefore, each control IC element 36 is connected to an arbitrary pair of first and second mats 11 on the mat 11 through one or two matrix circuit elements 35, 35 in response to a control signal supplied through the connector 37. Select two electrodes 22, 22,
After measuring the electric resistance during that time, the result can be output to the outside via the connector 37. However, the control IC
The element 36 may simply pull out the selected second electrodes 22 and 22 to the outside via the connector 37 and measure the electrical resistance between the second electrodes 22 and 22 using an external measuring device. The parameters measured at this time are:
First electrodes 21, 21 corresponding to the second electrodes 22, 22
Any electrical parameter other than the electrical resistance may be set as long as it can determine the quality of the pattern P between them.

The printed circuit board inspection attachment is used by being incorporated into an inspection apparatus 40 (FIG. 5). The inspection device 40 includes upper and lower frames 41 and 42, a pair of moving frames 43 and 44 disposed between the frames 41 and 42 so as to be able to move up and down, and a fixed frame 45 disposed between the moving frames 43 and 44. Are combined.

At the four corners of the lower frame 41, columns 41a, 41a,... That support the upper frame 42 and slidably penetrate the corners of the moving frames 43, 44 are erected. . The lower moving frame 43 is connected to cylinders 43a, 43a,... Erected on the lower frame 41, and supports the mat 11 upward through the support substrate 31 at the center. In addition, the upper moving frame 44 is provided with a cylinder 4 that is suspended from the upper frame 42.
4a, 44a,..., And supports the mat 11 downward at the center via a support substrate 31. In addition, a suction unit 46 is attached to the upper and lower frames 41 and 42 via a cylinder 46 a so as to be able to move up and down.
6b is connected. However, only one suction unit 46 is shown in FIG. Note that connection cables C, C,... From an inspection system (not shown) are connected to the sockets 37, 37,.

The fixed frame 45 is formed in a frame shape and is fixed to an intermediate portion of the columns 41a. The fixed frame 45 includes a support piece 45 having a suitable support material at the tip.
The printed circuit board B to be inspected can be detachably held via the a and 45a and the screw shafts 45c and 45c facing the support pieces 45a and 45a. A drive motor 45d is attached to each screw shaft 45c.

When the printed circuit board B is set on the fixed frame 45, the moving frames 43, 44 approach the fixed frame 45 via the cylinders 43a, 43a,..., Cylinders 44a, 44a, respectively (arrow K1 in FIG. 5). ,
K2 direction) Therefore, the upper and lower mats 11, 11
The printed board B can be sandwiched between the upper and lower sides and can be in close contact with the printed board B.

At this time, the suction units 46, 46 move together with the support substrate 31 through the cylinders 46a, respectively, and suck the center of the mat 11 toward the support substrate 31 through the through holes 31a, 31a. 11 can be held flat. Therefore, each mat 11 can make the first electrodes 21, 21... Contact the pattern surfaces on the front and back surfaces of the printed circuit board B. Therefore, each control IC element 36
Is selected by sequentially selecting an arbitrary pair of second electrodes 22, 22 via the matrix circuit elements 35, 35,.
First electrode 2 contacting any two points on printed circuit board B
1, 21 is selected, and the electrical resistance between them is sequentially measured, so that the quality of the printed circuit board B can be determined. afterwards,
The inspection device 40 may retract the moving frames 43 and 44 to their original positions, and remove the printed circuit board B from the fixed frame 45.

In the above description, the inspection apparatus 40 may hold the mats 11 and 11 and the printed board B vertically, move the mats 11 and 11 horizontally, and bring the mats 11 and 11 into close contact with the printed board B. May be fixed, and the other mat 11 may be moved together with the printed circuit board B. Further, the inspection device 40 may omit one of the moving frames 43 and 44 and inspect the printed circuit board B one side at a time.

The terminals 35a and 3 of the matrix circuit element 35
When the arrangement pitch of 5a... Is set sufficiently small, the first and second electrodes 21, 21,.
The same arrangement pitch d1 = d2 can be obtained. Also, blocks A, A,... That separate the second electrodes 22, 22,.
Can be determined according to the number of the second electrodes 22, 22,... That each matrix circuit element 35 can process.

[0033]

[Other Embodiments] Each first electrode 21 may have a rough surface at the tip (FIG. 6). The first electrode 21
By increasing the contact pressure per unit area, it is possible to improve the contact with the printed circuit board B.

The sub-electrodes 32, 32,...
22 may be individually connected (FIG. 7). Each sub electrode 32
Are embedded in the lower part of the second electrode 22 and are prevented from falling off, and the upper end is soldered on the surface side of the support substrate 31. Each of the second electrodes 22 has a flat front end, and forms the same plane as the surface of the mat 11. Therefore, the support substrate 31 can be held in close contact with the surface of the mat 11 via the sub-electrodes 32, 32,..., The second electrodes 22, 22,.

Are formed on the back side of the support substrate 31 and are connected to the second electrodes 22, 22 (FIG. 8A). May be formed on a rough surface (FIG. 2B). Each sub-electrode 32 can integrally connect the mat 11 and the support substrate 31 by adhering to the second electrode 22 via a conductive adhesive S.

The support substrate 31 may be made of an elastically deformable resin material or the like, and the central portion may be bulged to the back side (FIG. 9). However, FIGS. 6B and 6C are cross-sectional explanatory views corresponding to the lines X1-X1 and X2-X2 in FIG. The support substrate 31 is integrally connected to the mat 11 so that the central portion of the mat 11 bulges to the back side. Therefore, the support substrate 31 is deformed into a flat plate shape by bringing the mat 11 into close contact with a printed board (not shown) (two-dot chain line in the figure), and the mat 11 can be firmly brought into contact with the printed board.

[0037]

As described above, according to the present invention, the mat is provided with the first and second electrodes which are individually connected to the elastic mat via the conductive portions, so that the mat can be printed on the printed circuit board. The first electrode can be brought into contact with the pattern surface of the printed circuit board by being brought into close contact with, and any pair of the second electrodes pulled out through the conductive portion is selected, and the electric resistance between them is measured. Since the quality of the printed circuit board can be inspected, a highly reliable inspection result can be obtained within a short time, there is no contact failure, and it can be suitably used for a large-sized printed circuit board. effective.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional explanatory view of a main part.

FIG. 2 is an enlarged sectional view of a main part of FIG. 1;

FIG. 3 is a perspective view of the entire configuration.

FIG. 4 is an enlarged plan view of a main part of FIG. 3;

FIG. 5 is an explanatory view of a use state.

FIG. 6 is an enlarged cross-sectional view of a main part showing another embodiment (1).

FIG. 7 is an enlarged sectional view of a main part showing another embodiment (2).

FIG. 8 is an enlarged sectional view of a main part showing another embodiment (3).

FIG. 9 is a configuration explanatory view showing another embodiment.

[Explanation of symbols]

 B: printed circuit board d1, d2: arrangement pitch 11: mat 21: first electrode 22: second electrode 23: conductive part 31: support substrate 32: sub-electrode 35: matrix circuit element

Claims (5)

[Claims] 1. A mat having elasticity, a first electrode provided on a back side of the mat, and a second electrode provided on a front side of the mat, wherein the first and second electrodes are ,
An inspection attachment for a printed circuit board, which is individually connected via a conductive portion in the mat. 2. The method according to claim 1, wherein the second electrodes are arranged by increasing an arrangement pitch of the first electrodes.
Attachment for printed circuit board inspection as described. 3. The printed circuit board inspection attachment according to claim 1, wherein the second electrode is selected through a matrix circuit element. 4. The printed circuit board inspection attachment according to claim 3, wherein the second electrodes are arranged in accordance with a terminal arrangement of the matrix circuit element. 5. The printed circuit board inspection attachment according to claim 3, wherein the matrix circuit element is mounted on a support substrate having sub-electrodes to be combined with the mat.