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Wire bonding involves connecting the same or different types of material by means of high-speed thermocompression and/or ultrasonic bonding. A microwire or tape, which is generally made of gold or aluminum, is fused to the terminal surface (bondpad) on the chip, and to the corresponding contact points of leadframe and package, or taken to the substrate terminals and similarly bonded to these. The particularly stringent reproducibility and reliability (standardly 99.98%) requirements for the process demand an online process monitoring system for measuring the bonding force. As a result of the very small bonding forces and high accelerations caused by the rapid motion of the bonding arm, the design of such (generally customized) solutions for monitoring wire bonding forces requires a high level of know-how regarding the measurement of extremely small forces involved in dynamic processes. Kistler's expertise in this area has consequently already allowed the implementation of different solutions for well-known partners.
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