High performance nano colloid palladium and its application in horizontal PTH Journal of the HKPCA / 2017 / Summer / Issue No. 64 12 Technical Paper Abstract: A new kind of nano colloid palladium activator with new additive system and improved synthesis process is introduced here. The activator is applied to horizontal electroless plating process of PCB, compared with the traditional activated palladium system has high reactivity, excellent bath stability, low cost, stable back light performance and strong process capability. It can effectively improve and enhance the electroless copper plating binding force, which is suitable for the horizonal electroless copper plating process, with intelligent automation transformation demand. (Electroless copper plating) (Plating Through Hole) Cu Cu PCB PCB 2015 5 8 2025 80 PCB 2013 14.1% 2015 16% PCB 2+ [1 ] 2.1 Sn/Pd 40-100:1 Step 1: Pd + Sn + 6Cl [PdSn ]Cl Step 2: [PdSn ]Cl Pd + Sn + Sn + 6Cl - [2 ] 2+ 2+ - 4+ 2+ - 2 6 2 6