Etching liquid for circuit board based on nano sulfur dioxide

Abstract

The invention discloses etching liquid for a circuit board based on nano sulfur dioxide. The etching liquid is prepared from, by weight, 3.5%-6.5% of nano sulfur dioxide, 1.2%-1.6% of triethanolamine, 0.5%-1.6% of iodic acid, 2.5%-3.3% of organic hydrochloric acid, 1.5%-2.3% of non-ionic surface active agent, 0.5%-1.5% of stabilizer, 3.5%-5.6% of defoaming agent and the balance distilled water. Nano sulfur dioxide is newly added based on an original process, etching can be conducted under the condition that etch-resistant coating penetration does not occur, the etching speed of a chromium metal film is remarkably increased, controllability of the etching speed is achieved, degradation of the anticorrosion protective layer is effectively restrained, a chromium metal film wire harness with the flat and smooth surface is obtained, and high application value is achieved.

Description

technical field [0001] The invention relates to an etchant for circuit boards based on nanometer sulfur dioxide. Background technique [0002] At present, in the process of making circuit boards, the quality of circuit boards, the discovery and resolution of quality problems, and the evaluation of process improvement all need to be objectively inspected and judged by metallographic sections. The quality of the metallographic section directly affects the quality evaluation of the circuit board. The traditional metallographic slicing process includes sampling by milling; sealing the sample by resin mosaic method; grinding the sample; polishing the sample; microetching the sample. Wherein, the formula of the micro-etching liquid is 2-3 drops of hydrogen peroxide with a mass percentage of 50%, 8 ml of ammonia water with 25%-28%, and 8 ml of deionized water (DI water for short). The disadvantage is that the ammonia water in the microetching solution is volatile and has a pungen...