Fabrication method for flexible printed circuit (FPC) fine circuit

Abstract

The invention discloses a fabrication method for a flexible printed circuit (FPC) fine circuit. The fabrication method comprises the steps of substrate opening, laser drilling, black hole processing, full-board electroplating, slight etching combination processing of volcanic ash and a chemical medicine, dry film lamination in vacuum, laser direct imaging (LDI), dry film developing, dry film photocuring, circuit etching, automatic optical detection, and finished product package. The fabrication method for the FPC fine circuit is simple and scientific in design, copper particles are fine and uniform in surfaces after slight etching combination processing of the volcanic ash and the chemical medicine, a copper surface is good in roughness, and the binding force between a dry film and the copper surface is improved; the dry film is photocured, the binding force between the dry film and the copper surface is improved, etching of the FPC fine circuit is facilitated, and the reject ratio such as dry film dropping and circuit opening is reduced.

Description

technical field [0001] The invention belongs to the technical field of flexible circuit board manufacturing, and specifically describes a method for manufacturing a 30 μm / 30 μm fine circuit of a flexible circuit board. Background technique [0002] With the improvement of functions, light, thin, short and small operation requirements of communication, consumer electronics and other products, as well as the increasing degree of intelligence, higher requirements are put forward for FPC (flexible circuit board) for smart terminals, especially It is the ultra-fine trend of lines, from 100um to 50um lines, from 50um to 40um, 30um, 20um, the production capacity of ultra-fine lines has become an important indicator to measure the technical level of an FPC enterprise. At present, domestic enterprises can relatively maturely produce 50um / 50um lines, but for ultra-fine line 30um / 30um line FPC, most enterprises are still in the research and development stage and have not yet formed mas...

AI Technical Summary

Problems solved by technology

[0003] The main problems in the conventional manufacturing process: due to the FPC circuit design of 30μm / 30μm, problems such as dry film peeling and circuit gaps occur during circuit etching, resulting in a high rate of defective products in the circuit

Conventional FPC circuit pretreatment is chemical potion micro-etching, which forms a low roughness on the surface of the copper layer, so the bonding force between the dry film and the copper surface is not strong, and the dry film is easy to fall off when the dry film is developed, which is not suitable for making FPC fine line

Due to the FPC circuit design of 30μm / 30μm, the dry film after exposure and the copper surface of the circuit are too small (width 30μm), the adhesion between the dry film and the copper surface is not strong, and the dry film is prone to peeling off and circuit gaps during circuit etching. problem, resulting in a high defect rate of the line

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