| abstract |
The present invention relates to an aqueous phase pore sealing agent improving PCB coating oxidation-resistant and corrosion-resistant properties, consisting of, by weight, 4-12 parts of a corrosion inhibitor, 15-25 parts of a composite surfactant system, 10-20 parts of an ion chelating agent, 6-15 parts of a pH adjusting agent, 20-40 parts of a builder, and the rest being purified water. When used to perform pore sealing processing on a PCB, the aqueous phase pore sealing agent is diluted with purified water first to be diluted 10-100 folds, preferably, 100/8-100/3 folds. The pH value is 7-11, and is preferably 7.5-9.5. The surface tension is 18-28 dyn/cm. The pore sealing processing uses a soaking process, and preferably ultrasonic waves are added at the same time to assist in cleaning the pores. For the pore sealing processing, the temperature is 20-60 °C, and the time is 60-150 seconds. After the pore sealing, the temperature for drying the coated piece is 80-150 °C, and the time is 60-120 seconds. The PCB processed by the aqueous phase pore sealing agent of the present invention undergoes the neutral salt spray test, the nitric acid mist test, the mixed gas test, and the sulfur dioxide and bonding tensile force test, and the result indicates that the oxidation-resistant and corrosion-resistant properties of the coating thereof are significantly improved. |