Gold Ball Wire Bonding with Heated Tool for Automotive Microelectronics

摘要

Microelectronics used in automotive applications have grown considerably in the last few years with more hightech electronics controlling more functions in automobiles. In an effort to have more precise control and to reducevehicle weight manufacturers are integrating more functions into smaller packages. Many of these packages areembedded in molded plastic. This causes challenges when it comes to wirebonding these devices. They often cannotbe heated to traditional Gold Ball Thermosonic wirebonding temperatures of 120 - 150C. However, using a heatedcapillary to bond the parts which remain at room temperature simplifies the process considerably. Alternatives suchas pre-heating the parts in an oven and complex hot gas handler systems are not required. With a resistive wire coilheater surrounding a standard (or long capillary for deep access) sufficient heat can be provided to the wire bondsite for a strong and reliable interconnect. The bonding surface can be any material used in gold ball bonding:aluminum bond pads on die, plated contacts, ceramic substrates or plated copper traces on PCBs. This paper willshow that this heated tool process has been successfully utilized with 1mil Au wire and many of the standard dieand substrate materials with little impact on process parameters.