Action of Displacement Control on Vacuum Free Aluminum/Copper Diffusion Liquefaction Bonding
Quickness of fracture of Al oxide film is important especially for vacuum free Al/Cu bonding. Displacement amount and rate relate closely with fracture of oxide film and create clean surface. Displacement history during bonding process under static bonding load was measured for displacement control systematically. Displacement history under static load consists of three stages with creep and liquefaction. Higher bonding load increased displacement rate of each stage and decreased the thickness of Al oxide film grown by air heating. Suitable hearing time for bond also was shortened by increment of bonding load. Two types of displacement control were designed from these experimental results. One was the accelerated displacement rate control, another was the cyclic displacement control. Fracture of Al oxide film and liquefaction of bonding surface occurred at lower displacement than static load by each displacement control.
T. Chandra, N. Wanderka, W. Reimers , M. Ionescu
H. Kawakami et al., "Action of Displacement Control on Vacuum Free Aluminum/Copper Diffusion Liquefaction Bonding", Materials Science Forum, Vols. 638-642, pp. 3297-3301, 2010