Method for detecting inter-layer displacement of multi-layer flexible printed circuit board

Abstract

The invention discloses a method for detecting positional deviation between multilayer flexible printed wiring boards, which includes the following steps: A) a registration mark is respectively arranged at the same positions of layers that need paraposition on the multilayer flexible printed wiring boards; B) the registration marks of layers that need paraposition are compared to judge if the registration marks are at least partially overlapping; if so, the positional deviation among layers is considered within an acceptable range; otherwise, the positional deviation among layers is not considered within an acceptable range. The registration mark in the step A is a line mark which can detect the deviation amount between two axial locations which are mutually vertical on a surface; the line width of the line mark has the same size as that of the registration mark which need paraposition. The method has the advantages that the of digitally quantifying detecting result is digitally quantified,; meeting the detecting requirement of paraposition of arbitrary precision is met and raising the detecting efficiency is raised.

Description

technical field [0001] The invention relates to a method for manufacturing a multilayer flexible printed circuit board, in particular to a judging method for judging whether interlayer positions are shifted during the manufacturing process of a multilayer flexible printed circuit board. Background technique [0002] With the development of flexible printed circuit boards toward high density, the structure of multilayer circuit boards is the most commonly used type. Each layer of the multi-layer flexible printed circuit board consists of upper and lower insulating layers and an inner layer of copper foil located in between. The materials of each layer are combined with semi-cured glue as an adhesive and bonded by pressing. Wherein, the layers of copper foils are in a non-communicating state. Therefore, in order to connect some or specific parts of the lines of each layer, it is necessary to form a through hole by drilling, and then go through the step of electroplating the t...

AI Technical Summary

Problems solved by technology

In actual production, this judgment standard that does not use the digital quantity method needs to be judged by quality inspectors with naked eyes. However, due to certain differences among different people, the inspection results will also be uneven, and even defective products may be misjudged as good products.

However, if a measuring tool is used to check whether the deviation is qualified for each flexible printed circuit board, the production efficiency will be greatly reduced.

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