JPH02260696A - Method of inspecting multilayer printed board - Google Patents

Abstract

PURPOSE:To check and adjust a printed board before drilling so as to lessen defective by a method wherein the printed board undergoes X-ray fluoroscopy with a test board aligned with it. CONSTITUTION:When a hole is bored in a multilayered printed board, on which an insulating layer is formed among copper multilayer wirings, 1, 2, 3, 4, 5, and 6, so as to be in contact with the wirings 1, 4, and 6 but not with the wirings 2, 3, 5, a test board 8, which is formed of metal or the like almost immune from expansion or contraction and only a hole is provided to, is aligned with the multilayered printed board from above. The test board aligned with the printed board undergoes X-ray fluoroscopy to check a virtual drill hole position 20. By this setup, it can be checked if a hole boring position of a multilayer printed board is right or not before a drill processing, so that defectives can be lessened in number by making the fine adjustment of a hole boring position.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for inspecting whether or not hole processing is permitted before hole processing in a multilayer printed circuit board.

<Prior Art> Conventionally, the holes were actually measured and inspected, or holes were actually drilled and then inspected to see if they were completed correctly.

<Problem to be solved by the invention> When actually measuring, there are many points to inspect, and it is time-consuming and troublesome to measure and compare various distances.

Furthermore, if a hole is made, it is difficult to repair it. In addition, the processing alone causes process loss and also causes material loss.

Therefore, there has been a need for a method for inspecting multilayer printed circuit boards that can be easily inspected before holes are formed.

<Means for Solving the Problem> The above-mentioned method is attempted to be solved by the technology shown in the claims.

Function〉 The test boat is originally used to confirm the position of the drill hole after forming the drill hole, to check the number of drill holes, to check the expansion and contraction status of the board, and the reference holes for baking the baking film (practical version) are used for making jigs, etc. A board made of metal or resin, such as a plate, that has only holes with almost no expansion or contraction, and when used, the boundary between the hole and other parts where X-rays are shielded by the test board. becomes clear, making it possible to determine at a glance whether or not the holes are placed correctly.

<Example> FIG. 1 is a side sectional view showing an example of the present invention,
FIG. 2 is an X-ray plan view of the same.

In the multilayer printed circuit board, an insulating layer 7 of Galevo is formed between the copper multilayer wiring Li1.235.6. If holes are not made so that the holes are in contact with the wirings 1, 4.6 and not in contact with the layer 2.3.5, the signal line will be defective. Here, when the test board 8 is aligned from above and viewed through X-ray, it becomes clear at a glance whether or not a drill hole can be drilled at the virtual drill hole position 20. In other words, due to the relationship between the wiring outline 11, 12, 13, 14, 15, 16 and the hole 18 of the test boat, there may not be enough room to drill a hole where layer misalignment has occurred, or there may be expansion and contraction in the multilayer printed circuit board. It can be seen that the hole becomes defective.

<Effects of the Invention> According to the present invention, it is possible to check whether the hole is good or bad before drilling a hole, and it is possible to make fine adjustments by shifting the drilling position or changing the pinch to prevent defects.

In addition, it is possible to feed information about process defects to the immediately previous process.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing one embodiment of the present invention,
FIG. 2 is an X-ray plan view of the same. 1.2, 3, 4, 5.6... Wiring 7... Insulating layer 8... Test board 11, 12.13.14.15.16... Outline of wiring 18...Test board hole 20...Virtual drill hole position Applicant Kazuo Suzuki, Representative of Toppan Printing Co., Ltd.

Claims (1)

[Claims] 1) A multilayer printed circuit board inspection method in which a test board is aligned on the printed circuit board and examined with X-rays to determine whether there is room for drilling holes.