Presetting positioning fusion process for inner central layer of printed circuit board

Abstract

The invention discloses a pre-aligning and positioning fusion process of a printed circuit board inner layer core plate. The pre-aligning and positioning fusion process comprise the steps that the inner layer core plate is punched, and the inner layer core plate is pre-aligned and fused, in the step of punching the inner layer core plate, four positioning holes are punched on the core plate and dispersed at the edge positions adjacent to the peripheries of the four core plate, four corresponding positioning pins are arranged on a fusion machine working table, and after being aligned, the inner layer core plate is hot pressed and fused. The positioning error resulted from the deformation of the positioning holes is reduced by positing a plurality of holes, thereby, the positioning precision of fusing the inner layer core plate is improved, and the offset of the inner layer core plate can be controlled within 3.0 mil, so as to satisfy the requirements of positioning and fusing the inner layer core plate of the multilayer fine wire printed circuit board, and 24-layer fine wire circuit board (Mass Lamination) can be produced in batch by utilizing the process of the invention.

Description

[technical field] [0001] The invention relates to a printed circuit board processing technology, in particular to a pre-arrangement positioning fusion process for an inner core board of a printed circuit board. [Background technique] [0002] At present, the rapid development of printed circuit boards towards high-level and thin lines has put forward higher requirements for inter-layer alignment. There are two traditional MASS LAM inner lamination alignment methods, one is to use a riveting machine to rivet the core board and the prepreg with different layers, and the other is to use two round holes to position the different layers. The core board and the prepreg are fused together. The common feature of these two pre-arrangement methods is that the inner core board is punched with an automatic optical punching machine in advance, and then these two round holes are used for positioning to realize the positioning of core boards with different layers. purpose of overlay. [...

AI Technical Summary

Problems solved by technology

[0004] 1. When the inner core board is thin, it is pre-arranged by means of two-hole positioning and thermal fusion. During the process of board-fitting round pins, the round holes are easy to be broken; after browning, the board warpage is large, resulting in low alignment accuracy , the interlayer offset is large;

[0005] 2. Alignment prearrangement by rivet driving, based on the fact that there are multiple alignments during the rivet driving process, the cumulative error is large during the alignment process, resulting in a large amount of alignment offset between layers

[0006] In the long-term production process of the above two inner layer lamination positioning methods, it was found that for thin plates and high-layer multi-layer plates after pre-arrangement and X-ray machine inspection, there are different degrees of inner core plate offset, and the maximum offset reaches More than 7mil (mil is one thousandth of an inch, 7mil is equivalent to 0.18mm), which seriously restricts the quality of high-density thin circuit boards with high layers

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