JPH09135063A - Method of inspecting conduction of printed-wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the conduction test to be made leaving no contact traces at all on contact parts without controlling the pressurization of probes by a method wherein a printed-wiring board to be inspected is covered with a sheet conductive in the thickness direction when pressurized to bring a probe into contact therewith. SOLUTION: A pressure sensitive conductive sheet 11 becoming conductive in the thickness direction when pressurized is covered with a substrate 1 to be inspected. Next, the conduction test of printed-wiring board 1 covered with the pressure sensitive sheet 11 is performed by shifting the probes 8 to through holes 2 and foot prints 3 as the contact parts so as to move the probes 9 by a probe driving part. Through these procedures, the conduction test can be performed without controlling the pressurization of the probes 9 leaving no contact traces at all on the contact parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuity inspection method for printed wiring boards.

[0002]

2. Description of the Related Art Generally, there are several kinds of methods for manufacturing a printed wiring board. For example, after removing unnecessary portions of a copper foil to form a circuit conductor and making a hole with a drill or the like, electroless plating is performed. A method of forming through holes by copper plating, etc., or using a permanent resist to form a negative conductor pattern on the surface where conductor circuits will be formed, and after making holes using a drill etc. at the necessary locations, the circuit conductor A method of forming a through hole by electroless plating is known.

As shown in FIG. 2, the printed wiring board manufactured by the above-described manufacturing method has a disconnection 4 in the circuit conductor due to the accuracy of jigs and tools used in manufacturing, printing error when forming the circuit conductor by printing, and the like. A defect such as short circuit 5 may occur.

The disconnection of these circuit conductors and the short circuit between the circuits cause
Since it cannot operate normally as a circuit, it must be excluded. Therefore, a continuity test is performed to detect disconnection and short circuit.

The continuity test is a circuit test which is carried out by utilizing the test data created in advance and the test information obtained from the board to be tested.

Conventionally, when a plurality of probes are moved to a contact portion to conduct a continuity test, a probe unit 8 is attached to a through hole 2 and / or a footprint 3 of a printed wiring board 1 as shown in FIG. The probe 9 was moved and brought into contact with the probe 9 by moving it with a probe driving unit (not shown).

[0007]

In the conventional continuity inspection method, since the probe is brought into direct contact with the contact portion, contact pressure of the probe may cause contact marks such as dents 6 and flaws 7 as shown in FIG. there were.

An object of the present invention is to provide a method for conducting a continuity test without controlling the pressurization of a probe and without making a contact mark on a contact portion.

[0009]

A printed wiring board continuity inspection method according to the present invention is such that, when a pressure is applied to a printed wiring board to be inspected, a conductive sheet in the thickness direction (hereinafter referred to as a pressure-sensitive conductive sheet) is covered. It is characterized in that the probe is brought into contact therewith.

[0010]

In FIG. 5 of the present embodiment, a printed wiring board 1 is covered with a sheet 11 that conducts electricity, and a probe unit 8 is moved to a through hole 2 and / or a footprint 3 which are contact portions. Then, the probe 9 is moved and brought into contact with it to perform an inspection.

[0011]

An embodiment of the present invention will be described with reference to the drawings. FIG.
FIG. 6 is a diagram showing an example of a continuity inspection method using a pressure-sensitive conductive sheet. As shown in FIG. 5, the pressure-sensitive conductive sheet 11 is covered with the substrate 1 to be inspected from the direction in which the probe 9 contacts. Although not shown, the pressure-sensitive conductive sheet has its end fixed so as not to move. For the continuity inspection of the printed wiring board 1 covered with the pressure-sensitive conductive sheet 11, the probe unit 8 is moved to the through hole 2 and / or the footprint 3 which are the contact portions, and the probe 9 is moved by the probe driving portion (not shown) to make contact. Let's make an inspection. As shown in FIG. 6, the pressure-sensitive conductive sheet 11 is preferably made of a resilient material in which the conductive particles 10 are regularly arranged.

[0012]

As described above, according to the present invention, it is possible to provide a method for conducting a continuity test without controlling the contact pressure of the probe and without making a contact mark of the probe on the contact portion.

[Brief description of the drawings]

FIG. 1 is a top view showing an example of a printed wiring board for explaining a conventional example.

FIG. 2 is a perspective view showing an example of disconnection and short circuit occurring in a printed wiring board for explaining a conventional example.

FIG. 3 is a side view showing a conventional example.

FIG. 4 is a perspective view for explaining a problem of a conventional example.

FIG. 5 is a side view showing one embodiment of the present invention.

FIG. 6 is a cross-sectional view showing an example of a sheet that is used in one embodiment of the present invention and that conducts in the thickness direction when pressed.

[Explanation of symbols]

1. Printed wiring board 2. Through hole 3. Footprint 4. Disconnection 5. Short circuit 6. Indentation 7. Flaws 8. Probe unit 9. Probe 10. Conductive particles 11. A sheet that conducts in the thickness direction when pressed

Claims (1)

[Claims] 1. A printed wiring board characterized by covering a printed wiring board to be inspected with a sheet that conducts in a thickness direction when pressure is applied to the printed wiring board to be inspected, and bringing a probe into contact therewith. Continuity inspection method.