Multi-layered circuit board and manufacturing method thereof

Abstract

The invention provides a manufacturing method of a multi-layered circuit board, comprising the steps of: providing an inner-layer board and an outer-layer board; providing a film, presetting an opening area on the film, defining two parallel and opposite design reference lines for the opening area, forming a plurality of uniformly and continuously distributed sawtoothed structures or a plurality of uniformly and continuously distributed wavy structures which are convex towards the opening area at an opening edge area on the film adjacently connected with each design reference line; placing the film between the inner-layer board and the outer-layer board and utilizing a first rolling device to carry out thermocompression on the inner-layer board and the outer-layer board in a rolling manner along the direction vertical to the design reference lines; and providing a dry film, placing the dry film at the outer side of the outer-layer board, and utilizing a second rolling device to carry out thermocompression on the dry film to the outer-layer board. The invention also provides the multi-layered circuit board formed by utilizing the manufacturing method thereof.

Description

technical field [0001] The invention relates to circuit board technology, in particular to a multilayer circuit board with a specific adhesive layer structure and a manufacturing method thereof. Background technique [0002] With the rapid development of the electronic industry, the manufacturing technology of circuit boards, which are the basic components of electronic products, is becoming more and more important. The circuit board is generally made of a copper-clad substrate through a series of processes such as cutting, drilling, etching, exposure, development, pressing, and molding. For details, please refer to the article "Dielectric characterization of printed circuit board substrates" published by C.H.Steer et al. in Proceedings of the IEEE, Vol.39, No.2 (August 2002). [0003] Generally, a multilayer circuit board can be formed by thermocompression bonding of an inner layer board and an outer layer board. A film is arranged between the inner layer board and the ou...

AI Technical Summary

Problems solved by technology

However, during the thermocompression bonding process of the outer layer board and the inner layer board, the film will soften due to heat and become a molten state. When the thickness of the film is 25 μm, the drop at the edge of the opening area is 25 μm), so the gas trapped between the film and the outer or inner plate stays at the opposite edges of the opening area and cannot escape in time. Gas forms bubbles after thermocompression

In the subsequent processing of the multilayer circuit board, the bubbles will expand under heat to form a raised area, which not only affects the appearance quality of the multilayer circuit board, but also makes the multilayer circuit board easy to cause delamination during subsequent processing or use, causing the circuit board fail

Moreover, during the subsequent dry film lamination process of the multilayer circuit board, the copper layer of the outer layer board may be disconnected at the opening area of ​​the film due to the height difference, causing line breakage and affecting the conduction quality of the multilayer circuit board

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