Method for measuring expansion and shrinkage of printed circuit board, and printed circuit board

Abstract

The invention discloses a method for measuring expansion and shrinkage of a printed circuit board, and the printed circuit board. The printed circuit board comprises two outer layer boards and at least two inner layer boards arranged between the two outer layer boards, wherein each side of each inner layer board is provided with a test point, and test points on opposite sides of each inner layer board are positioned in the same horizontal line or vertical line. Each side of each inner layer board is provided with the test point, the test points on the opposite sides of each inner layer board are positioned in the same horizontal line or vertical line, after the inner layer boards are pressed, whether the two test points of two opposite sides of each inner layer board are expanded or shrunk is measured, the expansion and shrinkage data can be accurately measured, and data support is provided for the subsequent adjustment or modification of inner layer film compensation; therefore, the adverse effect of the circuit board caused by expansion and shrinkage can be effectively improved and the rejection rate of the circuit board is reduced.

Description

technical field [0001] The invention relates to circuit board manufacturing technology, in particular to a method for measuring the expansion and contraction of a printed circuit board and the printed circuit board. Background technique [0002] Printed circuit boards are generally made of multiple boards pressed together. The outermost two-layer boards generally play the role of insulation and protection. The middle multi-layer board is an inner layer board, on which the specific circuit of the circuit board is arranged. When producing circuit boards, multiple inner boards are first pressed into one board by pressing equipment, and then pressed with two outer boards. However, when the inner boards are pressed together, one or more layers of the inner boards will expand and shrink, resulting in defective or even scrapped circuit boards. [0003] see figure 1 , the existing technology generally adopts a circular test point at the corresponding position of the four corners o...

AI Technical Summary

Problems solved by technology

However, when the inner boards are pressed together, one or more layers of the inner boards will expand and shrink, resulting in defective or even scrapped circuit boards.

[0003] see figure 1 , the existing technology generally adopts a circular test point at the corresponding position of the four corners of each inner layer board. After the circuit board is pressed, these circular test points will form a concentric ring. Then, according to the concentric ring The distance between the ring and the ring, check whether the inner layer board is deflected and expands and shrinks, so as to detect which layer of the inner layer board has expanded and shrunk, but this method cannot actually measure the actual expansion and contraction of each inner layer board Therefore, this method cannot provide data support for subsequent changes in inner layer film compensation

[0004] Therefore, the expansion and contraction measurement technology of the existing circuit board still needs to be improved and improved.

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