| dc.description.abstract | In this study, the electroless plating Co (W, P) surface finish was successfully plated on printed circuit boards (PCBs). According to surface analysis and test, the electroless plating Co (W, P) in our work perform well quality and adhesion. Furthermore, the morphology and composition can be controlled by pH adjustment. The corrosion tests were treated in corrosion chamber with different surface finishes as following, electroless cobalt, copper, electroless nickel immersion gold (ENIG), immersion tin (ImSn). Compare with the corrosion resistive property with different surface finishes. In our study, substrate with Co (W, P) surface finish has better corrosion resistive under SO2 with 150 ppm. When the concentration of SO2 increased to 4000 ppm, large corrosion of all the samples were observed on the surface after 136 hours. The creep corrosion phenomenon, corrosion product, and crack were observed on the surface. In addition, the temperature humidity pressure test was also treated on those substrates with different surface finishes. At 85 oC and 85% relativity humidity, the Co (W, P) surface finish substrate shows great humidity resistive under 100 V. In summary, Co (W, P) surface finish has high potential to used on high reliability automobile printed circuit boards. | en_US |