Thermophysical properties of a soldered contact of a concentrator solar cell with a heat removing basement

Solder joint between InGaP/GaAs nanoheterostructures on Ge substrates and AlN ceramic heat dissipaters was studied by laser thermal wave and scanning electron microscopy methods. The study was focused on local thermal properties of the joint affected by structural changes in the solder alloy during reflow soldering. Laser thermal wave is applied for measuring local thermal conductivities of soldered joints By scanning electron microscopy, it is shown that metals in the contact layers affect the distribution of metal components inside the soldered joints. This inhomogeneous distribution of intermetallic phases results to decreasing heat transfer through the joint.