Method for detecting intra-layer registration of multi-layer circuit board and multi-layer circuit board

Abstract

The invention provides a method for detecting intra-layer registration of a multi-layer circuit board and a multi-layer circuit board. The method herein includes the following steps: drilling a multi-layer circuit board; at a preset datum line, microsectioning the drilled multi-layer circuit board; acquiring the lengths of one of at least two bonding pads which are vertically arranged on two sides of a drilling hole, and respectively marking the lengths as a first bonding pad length and a second bonding pad length; acquiring the lengths of another bonding pad of the at least two bonding pads which are vertically arranged on two sides of the drilling hole, and respectively marking the lengths as a third bonding pad length and a fourth bonding pad length; based on the first bonding pad length, the second bonding pad length, the third bonding pad length, the fourth bonding pad length and a preset registration formula, determining the intra-layer registration of the multi-layer circuit board. According to the invention, the technical solution reduces the cost for detecting intra-layer registration, increases the accuracy for detecting intra-layer registration, and increases the yield of the multi-layer circuit board.

Description

technical field [0001] The invention relates to the technical field of circuit board manufacturing, in particular to a method for detecting alignment between layers of a multilayer circuit board and a multilayer circuit board. Background technique [0002] The interlayer alignment of a multilayer printed circuit board (Printed Circuit Board, PCB) is an important quality parameter. For example, the distance between the through hole between the boards and the edge of the pad is required to be greater than or equal to 2mil. In addition, consider To the inner layer space limitation of multi-layer circuit boards, the interlayer alignment of PCB is required to be less than or equal to 5mil. Furthermore, some high-precision circuit boards require to reduce the signal interference of adjacent layers, and the interlayer of multilayer PCBs is required Alignment is less than or equal to 4mil. [0003] In the related art, there are mainly two detection methods for interlayer alignment ...

AI Technical Summary

Problems solved by technology

[0006] The above-mentioned first detection method is affected by the deviation of the drilling position, and the above-mentioned second detection method is affected by the X-Ray projection ability, especially for thicker copper plates or mandarin duck copper plates, the target will be blurred or cannot be grasped. leading to serious detection bias

In addition, the above two test methods require corresponding high-precision test equipment and software, and the test cost is high.

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