Pulsed current resistive heating for bonding temperature critical components

摘要

Controlled current pulses applied to a shaped resistive heating element formed on the bonding surface of a base or substrate component provide sufficient heat to the bonding interface formed between a chip and the base bonding surface to produce a high bonding temperature at the bonding interface while maintaining an opposite surface of the chip at or below a relatively low temperature critical for components formed or mounted on the chip surface. A layer of a thermally setting thin-film bonding agent is applied over a serpentine-shaped resistive heating element having a relatively narrow linewidth formed on the base component bonding surface. The chip to be bonded is retained in a desired position against the bonding surface over the heating element and bonding agent layer while a current pulse is applied to the heating element via contact pads. The current pulse magnitude and duration are controlled to produce sufficient local heating at the bonding interface to effect the desired bonding without excessive heating of any critical components at some predetermined distance from the bonding site.