1992 Volume 10 Issue 1 Pages 144-149
The thermal distribution of the bond including electrode tips during bonding process is shown experimentally and the role of bonding parameters such as electrode force, input power, and current duration is clarified in micro parallel gap bonding processes. Furthermore the formation of the bond is investigated experimentally at the bonding of copper alloy lead and thick film (Ag/Pd) with 20μm thickness on the 96% alumina substrate.
To obtain the bonds with high quality, it is very important to control both the thermal distribution of the bond and its stability.
Resulting from the each voltage value of bonding parts, it is clarified that heat generation mainly occurs at the part between electrode tips and copper alloy lead by joule's heating and the current mostly flows into Cu alloy lead through the electrode tip, and so the current from copper lead to thick film is very small. As the result, temperature rise of the bond is caused by heat conduction from the part at the interface of the eletrode tip and copper lead.
Tensile shear load of the bond is influenced by power input, current duration under constant electrode force. Maximum load of the bond can be obtained with a shorter current duration by increase of the power input and the substrate is fractured by thermal shock, but expulsion occurs at the interface of the electrode tips and copper lead by increasing with the current duration.
