METHOD AND DEVICE FOR SOLDER BONDING

PURPOSE:To decrease the bonding defects by cleaning a bonding surface and a solder foil with accelerated particles, thereafter coating the surface with inactive metal and performing heating and bonding. CONSTITUTION:After the pressure in a chamber is made to be 10Torr with an exhausting device 9, Ar is introduced with a gas-pressure controller 10. Thus, the pressure is controlled at the 10Torr level. Then, a reverse-sputtering high-frequency power supply 13 is turned ON, and the high-frequency voltage is applied op a reverse-sputtering electrode 11. Thus, a substrate 12 becomes negative by the self-bias action of the high frequency. The substrate 12 is sputtered with positive Ar ions and cleaned. Then, a shutter 16 between the substrate and a target is opened, the positive voltage is applied on the sputtering electrode and the target is sputtered. Inactive metal is formed in the substrate, and oxidation is prevented. The semiconductor foil, whose oxidation is prevented, is left alone in atmosphere for one hour. Then, the semiconductor foil is held between two Ni-plated copper plate and heated and bonded in a hydrogen-atmosphere furnace. Thus the bonding defects can be reduced to approximately zero.