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

这个小企业创新研究第一阶段项目将为电子行业开发一种环保，低成本，精细间距和高可靠性的倒装芯片互连。该技术的最终目标是开发一种工艺，该工艺从具有铝（Al）或铜（Cu）键垫的半导体集成电路（IC）开始，并使用无铅焊料生成可以用于倒装芯片键合的IC。第一阶段项目将演示使用纳米材料组合在铜衬垫上打印凹凸金属（UBM），并将沉积物热转化为可焊接的层状金属薄膜，然后使用高温焊喷打印技术在UBM上打印无铅焊点。该技术的商业应用可以降低电子工业的成本和周期时间。倒装芯片的性能和尺寸优势将以最低的入门成本用于小批量应用。不需要光刻，真空工艺，电镀工艺或铅。这不仅降低了制造和设施成本，而且还用环保的添加剂工艺取代了历史上危险的工艺（光刻和电镀）。

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.