Coarse Copper Deposition Method for Full Board Cover Film Rigid-Flex Board

Abstract

A method for coarsening and copper deposition of a full-board cover film flexible-rigid combination board comprises: step one, laminating combination layers of a full-board cover film and a flexible-rigid combination board according to a preset laminated structure to form the full-board cover film flexible-rigid combination board; step two, performing drilling; step three, utilizing a plasma to perform coarsening and remove smears on a hole wall after the drilling; step four, performing copper deposition treatment and utilizing an acidic oil removing agent to perform oil removal before the copper deposition treatment; and steps five, performing electroplating to increase the thickness of a via hole and a surface copper layer, wherein copper in the hole formed by drilling and face copper on the surface of the flexible-rigid combination board respectively meet the respective copper thickness standard. By means of the method for the coarsening and the copper deposition of the full-board cover film flexible-rigid combination board, the conventional potassium permanganate system wet-process coarsening of the full-board cover film flexible-rigid combination board is omitted and replaced by plasma coarsening treatment, so that the desmear effect of the hole wall can be achieved, and the cover film can be prevented from being damaged severely.

Description

technical field [0001] The invention relates to the field of printed circuit board manufacturing, and more specifically, the invention relates to a method for roughening and depositing copper on a rigid-flex board with a full-board covering film. Background technique [0002] The rigid-flex board is a multi-layer board that includes both a hard board part and a soft board part, and its hard board part can generally be bent to a certain extent. [0003] When producing soft and hard boards, considering the protection of the exposed soft board area, a cover film will be pasted on its surface to protect the soft board and the circuit of the soft board; It is difficult to make plate roughened copper sinking. [0004] Specifically, for a rigid-flex board with a cover film attached to the entire board, after lamination and drilling through holes, the cover film will be exposed on the hole wall. Since the adhesive layer material of the commonly used cover film is acidic polyacrylat...

AI Technical Summary

Problems solved by technology

[0003] When producing soft and hard boards, considering the protection of the exposed soft board area, a cover film will be pasted on its surface to protect the soft board and the circuit of the soft board; It is difficult to make plate roughened and deposited copper

[0004] Specifically, for a rigid-flex board with a cover film attached to the entire board, after lamination and drilling through holes, the cover film will be exposed on the hole wall. Since the adhesive layer material of the commonly used cover film is acidic polyacrylate, and currently The most commonly used roughening potion for roughening line is alkaline potassium permanganate series potion. The degreasing of copper wire is mostly alkaline degreaser. Both will attack the covering film leaking from the hole wall, that is, the conventional roughening copper deposition treatment will cause the wicking effect on the hole wall of the soft-hard bonded board, resulting in serious quality and safety hazards

[0005] In view of the above problems, the existing technology proposes to choose the thickening solution of concentrated sulfuric acid system (or other non-alkaline roughening solution). However, the roughening potion in the concentrated sulfuric acid system has poor ability to remove drilling dirt on the hole wall, and the effect is not ideal

[0006] Therefore, it is hoped to provide a full-scale comprehensive solution that can roughen the drilling smear on the hole wall and at the same time solve the serious wicking effect caused by the excessive erosion of the cover film in the process of roughening the hole wall of the full-board cover film. Rough copper deposition method for soft and hard bonded board with board cover film

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