Method for producing double-surface thick copper flexible working board

Abstract

The invention provides a method for producing a double-surface thick copper flexible working board. The invention is characterized by comprising the steps of a first step, drilling; a second step, chemical treatment; a third step, copper deposition; a fourth step, electroplating; a fifth step, pattern transferring; a sixth step, acid etching; a seventh step, covering film pressure-overlying, wherein the seventh step comprises procedures of A, treating a copper surface by means of a copper surface coarsening solution for etching the copper surface to a coarse surface and forming a honeycomb-shaped surface, B, in performing covering film pressure-overlying, utilizing silicone rubber with hardness of 45+ / -5 DEG C and temperature resistance of 250 DEG C above and below the substrate as accessories for ensuring high pressure overlaying effect of the covering film, and C, at a press jointing temperature of 190-200 DEG C and a press jointing pressure of 10-15Kg / m<2>, performing press jointing for 2-4 minutes, thereby jointing the substrate with the covering film for obtaining the working board. Because the technical solution is used, the method for producing the double-surface thick copper flexible working board has advantages of simple process, low cost, high drilling quality, and electroplating uniformity. The method further prevents the problems of bubbles on the covering film, filling glue insufficiency, thermal shock and laying in a reflow soldering test.

Description

technical field [0001] The invention relates to the field of circuit board production, in particular to a production method for a double-sided thick copper flexible working board. Background technique [0002] At present, the surface copper thickness of the flexible working board is generally 35um, and the hole copper is generally ≥12um. The process is relatively simple and the process is easy to control. However, when the conventional process is used to produce thick copper soft (such as surface copper thickness ≥ 70um), it will be quite difficult, and some problems cannot even be solved, as follows: (1) Drilling burrs and roughness in the hole Too large, hole deformation and other problems; (2) Poor plating uniformity, uneven plate thickness, residual copper on the edge of the plate or small line spacing during etching; (3) Press cover film has color difference, poor appearance, and line gaps will appear at the same time Insufficient glue filling in the position, prone to...

AI Technical Summary

Problems solved by technology

[0002] At present, the surface copper thickness of the flexible working board is generally 35um, and the hole copper is generally ≥12um. The process is relatively simple and the process is easy to control.

However, when the conventional process is used to produce thick copper soft (such as surface copper thickness ≥ 70um), it will be quite difficult, and some problems cannot even be solved, as follows: (1) Drilling burrs and roughness in the hole Too large, hole deformation and other problems; (2) Poor plating uniformity, uneven plate thickness, residual copper on the edge of the plate or small line spacing during etching; (3) Press cover film has color difference, poor appearance, and line gaps will appear at the same time Insufficient glue filling in the position, prone to bubbles, delamination in thermal shock and reflow soldering tests; (4) Cracks in the copper layer in the bending test

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