Transient Closed-Loop Heating for Localized MEMS Bonding

We achieve practical closed-loop control of a microfabricated resistive heating trace inmillisecond-scale transient regimes for MEMS local solder bonding. This is one or two orders ofmagnitude faster than previous implementations and may be competitive with laser assistedbonding. We also present simple theoretical models for analyzing these heaters, then identify andanalyze a possible failure mode due to local thermal fluctuations in more complex heater traces.Together, these represent significant progress toward making resistive localized bonding forgeneral packaging purposes practically feasible.