Damage Analysis of Semiconductor Chip during Wire Bonding Process
Wire bonding, a process for connection between a semiconductor chip and a lead frame by thin metal wire, is one of the important processes of electronic packaging. Figure 1 shows a silicon chip connected with a lead frame by gold wire. The gold wire bonding process is performed as shown in Figure 2. (1) A tip of gold wire put out from a capillary is melted by an electric torch, and takes a ball shape by its surface tension. (2) A capillary goes down and presses the gold ball on an aluminum terminal set on a semiconductor chip. (3) The capillary is vibrated by ultra sonic for connecting the gold ball with the aluminum terminal. (4) The capillary moves and mashes the gold wire on a lead finger. The quick wire bonding process shorter than 0.1 seconds is desired for high performance of a wire bonding machine. High contact pressure is useful for shortening the process cycle, but it sometimes causes the damage of the semiconductor chip. Especially, a GaAs chip is easy to be broken. This paper presents the damage estimation of a GaAs chip during the gold wire bonding process.
KeywordsGallium Arsenide Maximum Principal Stress Wire Bonding Gold Wire Strain Rate Dependence
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