Development Of Micro-etching Agent For The Precise Printed Circuit Board

PCB (Printed circuit board) is not noly the basic components of various consumingand investing electronic products, but also a most important link of the modern electronicpackaging technology. With the miniaturization, digitization and multi-functionalization ofelectronic products, the electronic components are progressing to high density, which makethe line more and more delicate and hard to manufacture. Micro-etching, as a very importantprocess for producing the precise PCB, its quality is totally depended on the agent with goodperformance. As an excellent micro-etching system, H2SO4/H2O2is widely used.A series of factors influencing the micro-etching system of H2SO4/H2O2were studied, itwas found that:1) the main influencing factors of the etching rate includes the operatingtemperture, main ingredient, organic acid and stabilizer;2) due to the weak foaming ability,composites with a small amount of organic solvent and acid，the bybutanol phosphateachieves a good cleaning effect and eliminate the continued oxidaion problem of the PCBatfer process;3) it is effective to regulate the roughness of PCB surface atfer process byadding some alcohols into the agent;4) the stabilizer which enhance the stability of H2O2andinhibit the catalysis decomposition of metal ions, not only make the micro-etching processeasier to control’ but also extend the expiration.Base on these studies, a good quality, high eiffciency and better control micro-etchingagent was developed, and the composition is as follow;98%sulfuric acid175mL/L,30%hydrogen peroxide300mL/L, cyclohexanone6g/L, butanol phosphate9g/L，acetic acid2g/L, butanol15g/L,1,4-butylene glycol30g/L, dicyandiamide formaldehyde resin3g/L andmodiifed polyacrylamide3g/L. And the optimized operating condition is determinded asfollow: application temperature30°C to45°C, the storage condition is seal and avoidlight below30aC. Under these conditions, the micro-etching rate reach6to10|im/min, theagent not only make the copper surface clean, bright and properly rough, but also extend theexpiration to more than6month.Beside the high efficiency and easily controlling, the developed agent also reducesenergy consumption because of the lower operating temperature. The agent is expected toreplace the foreign agent in production and reduces the costs of PCB products to improve thecompetitiveness of the local products and create the significant economic and social beneifts.