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

Abstract

The invention discloses a process for pre-arrangement, positioning, and fusion of inner core boards of printed circuit boards, which includes punching holes for the inner core boards, pre-arranging and fusing the inner core boards, and in the step of punching the inner core boards, The core plate is punched with 4 positioning holes, and the 4 positioning holes are scattered on the edge of the 4 peripheral edges of the core plate. The workbench of the fusion machine is provided with 4 corresponding positioning pins, and the plates are hot-pressed and fused after being arranged. The multi-hole positioning of the present invention reduces the positioning error caused by the deformation of the positioning hole, improves the positioning accuracy of the fusion of the inner core board, and the offset of the inner core board can be controlled within 3.0mil, which satisfies the multi-layer fine line printed circuit According to the requirements of positioning fusion of the core board in the board, the process of the present invention can be used to mass-produce 24-layer thin circuit boards (MASS LAM lamination).

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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