Atmospheric Pressure Plasma Surface Treatment for Solderability Enhancement on Printed Circuit Boards

Packaging is the core of protecting integrated circuits (ICs), chips, etc., from environmental and/or external damage. Assembly process prior to packaging is needed, particularly in solder mounting. It is the process to interconnect ICs onto printed circuit boards (PCBs) where molten tin-based solder is placed between them. During the reflow of molten solder on metal PCB substrates, the metal atoms are directly connected with solder surface atoms. Intermetallic compound (IMC) is growth in the interface as product of metal-to-metal joint. The bonding will not well-developed when substrate surface has some contaminations, i.e. oxide and organic. Narrow solder spreading is also another indication of the presence of impurities on substrate surface. An approach to suppress this issue is to add surface treatment prior to solder reflow. Some methods are established and one of them is a non-thermal plasma surface treatment works in atmospheric pressure.