Integrated flip-chip flex-circuit packaging for power electronics applications

A novel flip-chip flex-circuit packaging platform is described that enables integration of multiple power dies and control circuitry with an advantageous form factor. A key attribute of this packaging platform is to extend the well-established flex-circuit and flip-chip soldering technologies in signal electronics to power electronics applications. The planar interconnection and flip-chip method facilitate multilayer packaging structure with reduced packaging dimensions and reduced packaging parasitics. A half-bridge test vehicle designed and fabricated for dc/ac inverter applications (42 V, 16 A) with an overall flex-circuit module footprint less than 30% that of a discrete device printed circuit board implementation has been modeled and demonstrated experimentally. Electrical results, confirmed with circuit simulation incorporating parasitic inductance electromagnetic modeling, have shown a turn-off voltage overshoot reduction of over 40% and a switching energy loss reduction of 24% with the flip-chip flex-circuit implementation. The power flex platform has a strong potential for integrated multichip power module applications that require minimized packaging size and parasitic inductance for high switching frequency and efficiency. Index Terms--Flex-circuit, flip-chip, packaging parasitics, power electronics packaging, switching energy loss, voltage overshoot.