JPH0458166A - Withstand voltage testing method for multi-layered printed wiring board - Google Patents

Abstract

PURPOSE:To test the withstand voltage between through hole conduction parts efficiently by moving an electric conductor on an insulating sheet where a hole is formed at the position of one of the through hole conduction parts and bringing the electric conductor into contact with the through hole conduction part, and bringing the electric conductor into contact with the other through hole conduction part through a conductive pin. CONSTITUTION:When the electric conductor 17 is moved on the insulating sheet 14, the electric conductor 17 contacts one through hole conduction part 2 at the position where the hole is formed on the insulating sheet 14 to conduct to the through hole conduction part, and neither contacts the other through hole conduction part 3 at the part where not hole is formed nor conducts it. Further, the electric conductor 17 is connected to the conductive pin 16, which contacts the other through hole conduction part 3 at the part where no hole is formed, so the through hole conduction part 2 at the position where the hole is formed and the through hole conduction part 3 at the position where no hole is formed are connected. Consequently, the withstand voltage between both the through hole conduction parts 2 and 3 can be measured efficiently.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a through-hole conductive device provided on the inner wall of each through-hole of a multilayer printed wiring board, and provided with a pad portion whose end protrudes onto the surface of the wiring board. This invention relates to a withstand voltage test method for multilayer printed wiring boards that performs a withstand voltage test between parts.

(Prior art) Generally, a multilayer printed wiring board has many electronic components mounted on it.
Since it is the base material that interconnects and functions these parts, the higher the voltage resistance, the more long-term reliability can be guaranteed.

On the other hand, since a multilayer printed wiring board is formed by an etching method and then bonded in multiple layers, as shown in FIG. Due to factors such as foreign matter 10 entering the clearance 9, the voltage resistance may be reduced.

For this reason, withstanding voltage testing of multilayer printed wiring boards is essential, and conventional methods for conducting this test include the following three methods: 1. Selecting the circuit to be measured and sequentially testing it with a withstanding voltage testing machine. There were two methods: (manual test), (3) testing with a continuity tester, and (3) testing with an automatic withstand voltage tester.

(Problem to be Solved by the Invention) However, although the conventional method 1 above is suitable for products with relatively few measurement points, such as between the power layer and ground layer of a multilayer printed wiring board, Testing the withstand voltage between the signal line and the power supply layer or ground layer requires a lot of man-hours and is an inappropriate method.

Further, method 2 above is automatically performed using a jig 13 equipped with contacts 12 that make electrical contact with all the through-hole conductive parts of the multilayer printed wiring board 1 as shown in FIG.
There are problems in that it takes time and money to manufacture the jig 13, and that a general continuity tester can only perform a withstand voltage test of about 250 V to 500 V.

Furthermore, since method 3 requires the same jig as methods 1 and 2, there is a problem in that the jig is expensive to manufacture, similar to method 1 and 2.

Therefore, the present invention provides a withstand voltage test method for multilayer printed wiring boards that can be performed efficiently at low cost without using a jig equipped with a contact that makes electrical contact with all the through-hole conductive parts of the wiring board. The purpose is to provide

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a through hole that is provided on the inner wall of each through hole of a multilayer printed wiring board, and has a pad portion whose end protrudes onto the surface of the wiring board. In the withstand voltage test method for multilayer printed wiring boards that performs a withstand voltage test between conductive parts, determine the through-hole conductive parts to be tested, and make a hole with a diameter larger than the outer diameter of the pad part of one of the through-hole conductive parts. An insulating sheet formed at a position corresponding to the pad part is laid on the top surface of the multilayer printed wiring board described in 1 above, and a conductive pin is brought into contact with the other through-hole conductive part to make a conductive layer on the insulating sheet. This method is characterized by carrying out a withstand voltage test between the through-hole conductive parts as described in 1. by moving the conductor connected to the pin.

(Function) According to the above configuration, when the conductor is moved on the insulating sheet, the conductor comes into contact with one of the through-hole conductive parts at the position where the hole is formed on the insulating sheet, and conducts with one of the through-hole conductive parts. ,
There is no contact with the other through-hole conductive part in the part where no hole is formed and there is no conduction.

In addition, the conductor is connected to a conductive pin, and the conductive pin is in contact with the other through-hole conductive part where no hole is formed on the insulating sheet, so the position where the hole is formed on the insulating sheet is The through-hole conductive part and the through-hole conductive part at the position where no hole is formed are connected, and the withstand voltage between the two through-holes can be measured. Further, if there are a large number of through-hole conductive parts of one of the above, the withstand voltage can be continuously measured by moving the conductor.

(Example) Hereinafter, an example of the withstand voltage test method according to the present invention will be described based on the accompanying drawings. In this embodiment, a withstand voltage test is performed between the signal line through-hole conductive part and the ground through-hole conductive part.

First, in the multilayer printed wiring board of this embodiment, as shown in FIG. 2, in addition to the signal line through-hole conductive section 2 and the ground through-hole conductive section 4, a power supply through-hole conductive section 3 is formed. These through-hole conductive parts 2. 3.
4 are each provided with a butt part 7, while a signal line 8 is connected to the signal line through-hole conductive part 2, a power layer 5 is connected to the power supply through-hole conductive part 3, and a ground layer 6 is connected to the ground through-hole 4. has been done.

As shown in FIG. 1, the withstand voltage test method of this embodiment consists of an insulating sheet 14, a spring-loaded pin 16 inserted into the ground through-hole conductive part 4, and a conductive conductor that moves while rotating on the insulating sheet 14. This is carried out by using a conductive rubber roller 17 and a withstand voltage tester 15 that is connected to the conductive rubber roller 17 and the spring-loaded pin 16 and performs a withstand voltage test. The insulation sheet 14 used in this example has a thickness of 0.2 mm.
A hole approximately 0.2 mm larger than the outer diameter of the butt part 7 of the signal line through-hole conductive part 2 is formed, and is located in the power supply through-hole conductive part 3 and the ground through-hole conductive group part 4. There are no holes formed in the area where the

In order to conduct the withstand voltage test of this embodiment using the above-described apparatus, first, the "-2" insulating sheet 14 is laid on the upper surface of the multilayer printed wiring board 1.

Next, the spring-loaded pin 16 connected to one terminal of the withstand voltage tester 15 is inserted into the ground through-hole conductive portion 4 and brought into contact.

Then, the output J voltage of the withstand voltage tester 15 is set to 1000 V, and the conductive rubber roller 17 connected to the other terminal is moved by the through-hole conductive portion 2'' of the insulating sheet 14. Then, the surface of the conductive rubber roller 17 is bent, and the conductive rubber roller 17 moves the butt part 7 of the signal line through-hole conductive part 2 at the position where the hole is formed on the insulating sheet 14.
However, it does not contact the power supply through-hole conductive portion 3 and the ground through-hole conductive portion 4 at positions on the insulating sheet 14 where holes are not formed.

Therefore, even if there are multiple signal line through-hole conductive parts 3, if the conductive rubber roller 17 is moved over the butt part 7 of the signal line through-hole conductive part 2, the conductive rubber roller 17 will sequentially conduct the signal line through-hole conductive part 2. The signal line through-hole conductive part 2 and the ground through-hole conductive part 4 are connected to each other by contacting the butt part 7 of the part 2, and a withstand voltage test can be continuously performed between the two conductive parts.

Therefore, according to this embodiment, even if there are multiple signal line through-hole butts, there is no need to use a jig or the like equipped with a contactor to make electrical contact with all the through-hole conductive parts of the multilayer printed wiring board. With the insulating sheet and the conductive rubber roller, the withstand voltage can be measured continuously.

In this embodiment, the conductive holes were moved on the insulating sheet, but in the present invention, other means other than the conductive roller, such as a conductive brush, etc., may be used, and the holes are moved through the insulating sheet. Any material may be used as long as it can be connected to the through hole in the formed portion. Furthermore, in this embodiment, the withstand voltage test was explained between the signal line through-hole conductive part and the ground through-hole conductive part, but in the present invention, the withstand voltage test was performed between the signal line through-hole conductive part and the power supply through-hole conductive part, for example. Of course, the withstand voltage may also be tested between the power supply through-hole conductive part and the ground through-hole conductive part.

(Effects of the Invention) As explained above, according to the present invention, the through-hole to be tested can be tested without using a jig or the like equipped with a contact that makes electrical contact with all the through-hole conductive parts of the wiring board. Between the conductive parts, one through-hole conductive part is brought into contact by moving the conductor over an insulating sheet with holes formed at that position, and the other through-hole conductive part is contacted by a conductive pin. Therefore, even if there are multiple through-hole conductive parts on one side, by moving the conductor, it can be brought into continuous contact with one of the through-hole conductive parts, thereby effectively increasing the withstand voltage at low cost. Tests can be conducted.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the withstand voltage test method for a multilayer printed wiring board according to the present invention, FIG. 2 is a sectional view showing an example of a cross section of a multilayer printed wiring board, and FIG. 3 is a diagram showing an example of a cross section of a multilayer printed wiring board. FIG. 4 is a cross-sectional view showing an example of a factor causing a decrease in withstand voltage. FIG. 4 is a cross-sectional view showing a test method using a conventional jig. 1... Multilayer printed wiring board 2... Signal line through-hole conductive section 3... Power supply through-hole conductive section 4... Ground through-hole conductive section 14... Insulating sheet

Claims (1)

[Claims] Provided on the inner wall of each through hole of the multilayer printed wiring board,
In a withstand voltage test method for a multilayer printed wiring board, which performs a withstand voltage test between through-hole conductive sections having pad portions whose ends protrude onto the surface of the wiring board, the distance between the through-hole conductive sections to be tested is determined. , Lay an insulating sheet on the top surface of the multilayer printed wiring board in which a hole with a diameter larger than the outer diameter of the pad part of one of the through-hole conductive parts is formed at a position corresponding to the pad part, and at the same time lay an insulating sheet on the top surface of the multilayer printed wiring board, A withstand voltage test of a multilayer printed wiring board is performed by contacting a conductive pin with the through-hole conductive part and moving a conductor connected to the conductive pin on the insulating sheet to perform a withstand voltage test between the through-hole conductive parts. Test method.