Abstract
Fluxless bonding process with pulse heat tip has been researched and developed by inserting both plated In/Sn and Sn layers at the bonding interface before bonding.
Quality improvement of the bond on the process has shown experimentally to be realize by inserting the thin Sn/In plated film on the surfaces of the lead and thin sheet as fine electronic materials, that is, tensile strength of the bond has been improved largely as the supply In plating layers with the thickness of 1-3μm on the Sn plated film (10μm) on the surface of Cu-Ni-Sn alloy lead, on bonding the lead and thin sheet with Sn plated film (10μm). This improvement is caused by both high oxidation resistance of Sn-In alloy and the expel of low temperature metal such as Cu-Sn-In etc from the interface of the bond during bonding.
Furthermore, the effect of bonding temperature lowering is clarified in the bonding process on assemblying electronic devices on a printed circuit board.
