Low line width and line space etching control method of thick copper plate

Abstract

The invention relates to a low line width and line space etching control method of a thick copper plate. The method comprises that cutting, boring and electroless copper plating are carried out on the thick copper plate, a dry film which does not cover holes is pasted to the thick copper plate after electroless copper plating, and exposure and development are carried out; after the developed thick copper plate is qualified in AOI scanning, patterned electro-coppering and electro-tinning are carried out, and first film removing, alkali etching and tin stripping are carried out successively; and when the thick copper plate after the first etching is qualified in AOI scanning, the dry film which does not cover the holes is pasted, exposure and development are carried out, patterned electro-coppering and electro-tinning are carried out after the cooper plate is qualified in AOI scanning, second film removing, alkali etching and tin stripping are carried out successively to obtain a circuit board, and a next procedure is moved to. The method can avoid board material waste caused by insufficient low line width and line space etching in integrated electroplating and etching of the board, etching burrs are reduced, the etching quality is improved, material consumption of the etching technology is reduced, and consumption of copper is reduced.

Description

technical field [0001] The invention relates to a processing method of a circuit board, in particular to a method for controlling the etching of a thick copper plate with fine line width and line spacing. Background technique [0002] With the continuous development of social economy, the demand for electronic products is also increasing, and the circuit boards widely used in electronic products have also achieved great development, especially PCB thick copper boards have been more and more widely used It has excellent thermal conductivity and resistivity, high dimensional stability and high temperature resistance, which meets the development trend and needs of the electronics industry. [0003] However, the current acid etching and alkaline etching methods for thick copper plates have certain defects: the acid etching method is to deposit copper through chemical deposition, so that the metal layer is attached to the wall of the via hole, and then thicken to the required cop...

AI Technical Summary

Problems solved by technology

[0003] However, the current acid etching and alkaline etching methods for thick copper plates have certain defects: the acid etching method is to deposit copper through chemical deposition, so that the metal layer is attached to the wall of the via hole, and then thicken to the required copper thickness by electroplating the entire board at one time. thick, and then paste the dry film covering the hole, after exposure and development, acid etching and film removal are carried out in sequence; the alkaline etching method is to attach a layer of metal layer to the wall of the via hole through chemical deposition of copper, and then through the whole board electroplating , thicken the copper thickness of the board surface and the via hole, and then paste the dry film without covering the hole. After exposure and development, perform graphic electroplating and electro-tin, and then perform film removal, alkaline etching and tin removal in sequence

[0004] In the above etching method, because the copper plate is too thick, the line width and line spacing are small, and the copper thickness of more than 140 μm is etched at a time, there is a very high probability that the line will be thin and the etching will not be complete, resulting in a high scrap rate; The parts that need to be etched in the later process are also plated with copper, resulting in waste of copper