This dissertation presents research on a new bonding technology using gold-tin multilayer composites and the study of thermal stress in die-attachment. Nearly perfect bondings were achieved as determined by a scanning acoustic microscope (SAM). After 40 cycles of thermal shock test, bonding degradation and die cracking were not observed. Scanning electron microscope (SEM) and energy dispersive X-ray (EDX) studies on the cross-section of the bonding layers reveal some basic mechanisms which might have occurred during the bonding process.;Monolithic microwave integrated circuits (MMICs) devices are extremely difficult to bond by using regular preforms due to their very small thickness and the large number of via holes on the devices. By using this new technology, 100 ;I have also developed a 240;This technology is not restricted to the use of the Au-Sn material and it can also be applied to other bonding materials. Successful die attach has been demonstrated at 200
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