K. Nishihori et al., THERMAL-ANALYSIS OF GAAS POWER MONOLITHIC MICROWAVE ICS MOUNTED WITH EPOXY ATTACHMENT, IEEE transactions on components, packaging, and manufacturing technology. Part A, 20(2), 1997, pp. 220-224
The effect of chip-mounting attachment on the thermal resistance of Ga
As power field effect transistor (FET) modules has been experimentally
investigated, The thermal resistance was evaluated for different GaAs
chip thickness of 150 and 250 mu m through an electrical method utili
zing temperature dependence of Schottky-barrier in the GaAs metal semi
conductor FET's (MESFET's). The thermal resistance of low-cost epoxy-m
ounted GaAs chips, suitable for uniplanar monolithic microwave IC's (M
MIC's), was found not to increase even up to a chip thickness of 250 m
u m, while that of AuSn-mounted GaAs chips increased as was convention
ally expected, Numerical simulation has also been presented for the si
milar case of GaAs power MMIC's. The result of simulation suggests tha
t lower thermal conductivity of attachment material, such as epoxy att
achment, leads to larger optimum chip thickness that minimizes the tot
al thermal resistance.