SBIR Phase I: Flip-Chip - Ink Jet Printed Under Bump Metal (UBM) and Lead Free Solder

This Small Business Innovation Research Phase I project will develop an environmentally friendly, low cost, fine pitch and high reliability flip chip interconnect for the electronic industry. The ultimate goal of this technology is to develop a process that begins with a semiconductor integrated circuit (IC) with either aluminum (Al) or copper (Cu) bond pads and results in an IC ready for flip-chip bonding using lead-free solder. The Phase I project will demonstrate printing the under bump metal (UBM) on Cu pads using a combination of nanomaterials and thermally converting the deposit into a solder wetable, layered metal film, and printing the lead free solder bumps on the UBM using a high temperature solder-jet printing technology. The commercial applications of this technology could lead to reduced cost and cycle time for the electronic industry. Flip chip performance and size advantages would be available to low volume applications at minimum entry costs. No photolithography, vacuum processes, plating processes or lead are needed. This not only reduces the manufacturing and facilities cost but also replaces historically hazardous processes (photolithography and plating) with an environmental friendly additive process.