JPH0244035B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printed wiring board inspection method and an inspection apparatus thereof, and more particularly, a sheet of anisotropically pressurized conductive rubber is applied to both the front and back surfaces of a printed wiring board as an object to be inspected. By clamping the shaped object and applying electricity from the connectors at both the left and right ends of the inspection jig board, it is possible to quickly and easily inspect the presence or absence of disconnections in printed wiring board patterns, continuity between patterns, and short circuits with high accuracy. It is an object of the present invention to provide a printed wiring board inspection method and inspection device that can be used.

Conventionally, electrical conductivity testing to check for disconnections in patterns on printed wiring boards, continuity, and short circuits in these patterns has been carried out using contact probes that are connected to the ends of patterns on printed wiring boards through upper and lower fixed insulating plates, as shown in Figure 1. This was done by inserting it into the

However, contact probes usually have a diameter of
Since the distance is about 1.5 mm to 2.0 mm, it is extremely difficult to test electrical conductivity between pads with a spacing of 2.0 mm or less.

Further, the contact probe needs to be fixed to an insulating plate with a thickness of about 10 to 20 mm, and the contact probe is used by inserting and fixing the contact probe into the fixing insulating plate. Therefore, it was necessary to drill a large number of holes in the fixing insulating plate for fixing the contact probe, and this work required a special dedicated hole-drilling jig that was placed under strict control.

On the other hand, as the circuit density of printed wiring boards has increased in recent years, it has become impossible to miniaturize devices using the conventional mounting method of inserting component lead wires into holes and soldering them. Techniques for attaching planar elements such as packaged ICs and for directly attaching liquid crystal displays have come to be required.

In such a printed wiring board, it is necessary to bring the contact probe into contact with both the front and back sides of the printed wiring board to be inspected.

However, when the contact probe is brought into contact with both the front and back sides of the printed wiring board, the contact pressure becomes uneven, and it is difficult to inspect the terminal portions of the pattern circuits on both sides for breakage.

In general, the relationship between the number of patterned circuits to be tested and the contact probes increases by requiring about twice as many contact probes as the upright circuits;
The work of arranging such a large number of contact probes on both the front and back surfaces of a printed wiring board to be inspected is a frequent task. In addition, with conventional testing methods, the number of probes used increases as the number of pattern circuits increases, and contact probes once fixed to an insulating plate cannot be easily reused. There were drawbacks such as extremely high costs.

The present invention eliminates the drawbacks of the conventional printed wiring board inspection method described above, and eliminates disconnection of patterns on both sides of the printed wiring board that is the object to be inspected, or conduction between patterns.
To provide an inspection method and an apparatus for the inspection, which can simultaneously inspect the presence or absence of short circuits quickly and accurately, and at low cost even on printed wiring boards with dense pattern circuits arranged at intervals of 2.0 mm or less. It is something.

That is, in the present invention, the test end of the printed wiring board to be inspected to be tested for continuity and the detection end of the test jig circuit board are directly opposed to each other, and the printed wiring board to be tested and the test jig circuit board are connected. A printed wiring board inspection method for inspecting the presence or absence of disconnections in the printed wiring board's patterns, continuity between patterns, or short circuits by sandwiching a sheet-like object of pressurized conductive rubber in different directions between the two, The test jig circuit board has a pattern circuit corresponding to at least the pattern circuit to be tested on the printed wiring board to be tested on the surface facing the printed wiring board to be tested, and A method for inspecting a printed wiring board and an inspection apparatus therefor, characterized by having an external extraction connector pad and an external extraction pattern that are electrically connected to the detection end corresponding to the inspection end of the printed wiring board to be inspected. be.

Therefore, the present invention has the following effects.

Since the test jig circuit board is used, there is no need to drill holes for fixing contact probes, etc., and the test jig is inexpensive, and can easily and accurately test fine and dense pattern circuits.

The test jig circuit board has a conductor pattern circuit and an external extraction pattern formed on the board surface, so it makes surface contact without damaging the pressurized conductive rubber in different directions, making it easy to connect with the pattern circuit to be tested. Eliminates misidentification due to poor contact.

Next, embodiments of the present invention will be described based on the drawings.

FIG. 2 is a diagram showing an embodiment of the printed wiring board inspection method and the inspection apparatus of the present invention, in which anisotropically pressurized conductive rubber is applied to both the front and back surfaces of the printed wiring board that is the object to be inspected. Press the sheet-like material of
The test end of the pattern circuit of the printed wiring board to be inspected and the detection end of the test jig circuit board are directly faced, and a longitudinal section of a part of the external extraction pattern and the external extraction connector pad that are electrically connected to the detection end is It shows. FIG. 3 is a perspective view showing an example of an apparatus used in the printed wiring board inspection method of the present invention, which substantially corresponds to the longitudinal cross-sectional view of FIG. 2 above.

In FIG. 2 above, first, the test jig board has patterns corresponding to the pattern circuits on both sides of the printed wiring board (hereinafter referred to as the printed wiring board to be tested) 1, which is the object to be tested for continuity. A circuit is formed on each surface facing the printed wiring board to be inspected. (Hereinafter, the test jig board will be referred to as the test jig circuit board.) In other words, the same pattern circuit as the pattern circuit to be tested on the printed wiring board to be tested should be placed opposite to the test jig circuit board. By forming the pattern in advance, it will directly face the pattern circuit on the printed wiring board to be inspected, and the edge of the pattern circuit to be inspected on the printed wiring board to be inspected (hereinafter referred to as
The test end) and the corresponding portion of the test jig circuit board (hereinafter referred to as the detection end 2) also face directly.

Further, the test jig circuit board is formed with an external lead connector pad 4 and an external lead pattern 5 which are electrically connected to the detection end 2.

Then, a sheet-like material 6 of pressurized conductive rubber having different directions is clamped between the test jig circuit 3 and the printed wiring board 1 which is the object to be tested. That is, the sheet-like material 6 of pressurized conductive rubber having different directions is placed on both the front and back surfaces of the printed wiring board 1 so as to be pressed.

In this way, after setting, a certain pressure is applied from the upper and lower sides of these integral parts and electricity is applied to the connector pad 4 to prevent disconnection of the patterns on the printed wiring board, conduction between the patterns, and short circuits. The presence or absence of a substance can be tested quickly, easily, accurately, and at low cost. As shown in FIG. 2, a sheet-like object 6 of pressurized conductive rubber with different directions, which is clamped between the printed wiring board to be inspected and the circuit board 3 of the inspection jig, is When the inspection end of the printed wiring board and the detection end 2 of the inspection jig circuit board are pressed together, a part of the rubber sheet-like material 6 at that part, that is, the pressurized conductive part 7 is pressed. This is because current will flow. Moreover, the pressurized conductive rubber sheet has different directions, and specifically, in the case shown in FIG. Current will flow only in that part.

That is, when the connector pad 4 is energized, a current flows through the pattern circuit of the inspection jig circuit board 3, and the current flows through the pressurized energized portion 7 of the pressurized conductive rubber sheet 6 in different directions. Electricity will flow through the pattern circuits of the printed wiring board to be inspected that correspond to the jig circuit board.
From this, the presence or absence of disconnection of the pattern circuit, continuity of the pattern, or short circuit is inspected.

Next, a printed wiring board inspection apparatus of the present invention will be explained.

In FIG. 3, a test jig circuit board 3 is provided on both the front and back surfaces of a printed wiring board 1, which is an object to be inspected, for clamping a sheet-like material 6 of pressurized conductive rubber in different directions. The test jig circuit board 3 is supported by a pressure rod 8 for applying pressure.
Further, on the surface of the inspection jig circuit board 3, there are provided a pattern circuit corresponding to the pattern circuit of the printed wiring board to be inspected, an external extraction pattern 5, and an external extraction connector pad 4 electrically connected to the pattern circuit. The electrically conductive portion 7 of the printed wiring board and the pressurized conductive rubber sheet 6 which is pressed onto the front and back surfaces of the printed wiring board is electrically connected to the printed wiring board. The test end of the test printed wiring board 1 and the detection end 2 of the test jig circuit board 3 are arranged to face each other directly at least in the portion to be tested. It is.

Further, as a method for forming a pattern circuit on the inspection jig circuit board 3, it can be created using a photographic film used for producing a printed wiring board to be inspected. That is, by transferring the photographic film while leaving only the necessary pattern circuit and shielding the other parts, the inspection jig circuit board can be easily and inexpensively produced using a predetermined method. .

On the other hand, the pressurized conductive rubber sheet 6 used in the present invention may be a commercially available anisotropic pressurized conductive rubber material, which is easy to obtain and can be reused. There are advantages.

A testing jig circuit board having a pattern circuit formed thereon opposite to the pattern circuit of the printed wiring board to be inspected as described above is used, and the printed wiring board to be inspected and the testing jig circuit board are arranged to face each other. Since we use anisotropic pressurized conductive rubber that conducts only to the conductive parts, it is possible to accurately detect pattern breaks or gaps between patterns, no matter how dense or double-sided the printed wiring board is. Continuity and short circuits can be tested.

Furthermore, the inspection apparatus of the present invention is versatile, and has effects such as being economically advantageous when exchanging jigs and the like.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a conventional method for testing continuity of printed wiring boards, FIG. 2 is a vertical cross-sectional view showing an example of the method for testing printed wiring boards according to the present invention, and FIG. 3 is a vertical cross-sectional view showing an example of the method for testing continuity of printed wiring boards according to the present invention. FIG. 2 is a perspective view of an apparatus used in the printed wiring board inspection method of FIG. In the above drawings, 1... printed wiring board, 2
...Detection end, 3...Inspection jig circuit board, 4...Connector pad for external draw-out, 5...Pattern for external draw-out, 6...Sheet-like material of pressure conductive rubber with different directions, 7... The conductive part of the sheet-like object, 8... pressure rod.

Claims (1)

[Claims] 1. The test end of the printed wiring board to be tested for continuity and the detection end of the test jig circuit board are directly opposed to each other,
A sheet of pressurized conductive rubber with different directions is sandwiched between the printed wiring board to be inspected and the test jig circuit board to prevent disconnection of the pattern of the printed wiring board, conduction between patterns, or short circuit. A method of testing a printed wiring board for the presence or absence of a printed wiring board, wherein the testing jig circuit board has at least a portion of the printed wiring board to be tested on a surface facing the printed wiring board to be tested. It has a pattern circuit that corresponds to the pattern circuit, and has an external lead-out connector pad and an external lead-out pattern that are electrically connected to the detection end that corresponds to the test end of the printed wiring board to be tested. A printed wiring board inspection method characterized by: 2. A printed wiring board to be tested for continuity is equipped with pressure conductive rubber with different directions on both the front and back sides, and a pattern circuit corresponding to at least the pattern circuit to be tested on the printed wiring board to be tested is placed on the outside of the rubber. A test jig circuit board having an external lead connector pad and an external lead pattern that are electrically connected to the detection end corresponding to the test end of the printed wiring board to be tested is placed on the test jig circuit board. A pattern circuit corresponding to the pattern circuit of the printed wiring board for inspection and a pattern circuit of the printed wiring board to be inspected are arranged so as to face directly,
A printed wiring board inspection apparatus is provided with a means for integrally pressurizing the printed wiring board to be inspected, the pressure conductive rubber having different directions, and the circuit board of the inspection jig.