PCB dry ice particle etching method

Abstract

The invention relates to a PCB (Printed Circuit Board) dry ice particle etching method, which comprises the following steps of: spraying dry ice particles to the upper surface and the lower surface of a PCB in an etching groove in the upper direction and the lower direction through a spraying device, vertically spraying the dry ice particles upwards or downwards on the PCB under the action of spraying pressure, and enabling etching liquid medicine to vertically permeate downwards under the extrusion of the dry ice particles, according to the etching method, dry ice particles are dissolved in etching liquid medicine to become carbon dioxide gas to be separated out, and the carbon dioxide gas is diffused from the middle of the PCB to the two sides, so that etching of copper surfaces on the two side walls of the PCB is inhibited. The PCB dry ice particle etching method has the advantages of being good in etching uniformity, low in lateral erosion degree and the like.

Description

technical field [0001] The invention relates to the technical field of circuit board production, in particular to a PCB dry ice particle etching method. Background technique [0002] Etching is the key technology for forming lines on the surface of PCB. It can retain the required copper surface by etching away the unnecessary copper surface. The inner layer graphics or the outer layer graphics are both important processes. However, as the line width and spacing shrink, In order to improve the process capability, anti-side erosion is particularly important. [0003] At present, the traditional etching potion method is used to etch the PCB surface, and there are the following technical problems: [0004] (1) Generally, the thickness of copper is 30 microns, and the line width / line spacing is less than 75 microns, which will cause incomplete etching, excessive etching will cause side erosion greater than 30%; [0005] (2) The uniformity of etching needs to be improved. Where ...

AI Technical Summary

Problems solved by technology

[0004] (1) Generally, the thickness of copper is 30 microns, and the line width / line spacing is less than 75 microns, which will cause incomplete etching, excessive etching will cause side erosion greater than 30%;

[0005] (2) The uniformity of etching needs to be improved. Where the plate is thick and thin, the etching is not complete while the etching is excessive