Highly reliable die attachment on polished GaAs surfaces using gold-tin eutectic alloy

Abstract

GaAs test dice with polished surfaces were successfully bonded on alumina substrates using Au-Sn alloy. The bonding process was carried out in H/sub 2/ or N/sub 2/ atmosphere with applied static pressure, but without the use of scrubbing. The quality of the bonds was examined by a scanning acoustic microscope (SAM) having a spatial resolution of 25 mu m. After 100 cycles of thermal shock between -196 degrees C to +160 degrees C, perfectly bonded devices remained perfect, as confirmed by the SAM images. No void was induced, and the dice did not crack. The results of a shear test indicate that the strength of the bondings is greater than that of the GaAs dice.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>