A Reliable Method for Direct Chip Attach for Mixed Technology Integration

Period of Performance: 11/05/1998 - 07/31/2001

$750K

Phase 2 SBIR

Recipient Firm

Aguila Technologies, Inc.
253 Pawnee Street
San Marcos, CA 92078
Principal Investigator

Abstract

The emergence of compact products employing mixed technologies, such as personal digital assistants, wireless communicators and sensor systems, is creating a host of new needs in electronics packaging. These products are driven by small size, light weight, high-operating frequencies, unique micro-to-macro interfacing and low cost. There is a need for a simplified and reliable process for direct chip attachment. Through under-filling the chip with a solid encapsulant, direct chip attach technology is now a reliable method for attachment of small chips to polymeric substrates. The encapsulant re-distributes stress in the package from the fatigue-intolerant solder joints. However, the encapsulant's effect is to force the chip and the substrate to take up the strain, bulging the substrate and the chip. This bulging causes its own new set of problems such as making larger chips susceptible to cracking during bending. Another problem is that the degree of bulging, and hence the degree of strain relief, is highly dependent on the flexibility of the structure of the underlying substrate. For MEMs, this bulging will have significant impact on the performance of the device attached. The objective of this proposal is to continue Phase I efforts that showed feasibility of demonstrating a new, reliable, compliant direct chip structure that eliminates this bulging.