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

这个小型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、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）接合焊盘的半导体集成电路（IC）开始，并导致IC准备好使用无铅焊料进行倒装芯片接合。第一阶段项目将展示使用纳米材料的组合在Cu焊盘上印刷凸块下金属（UBM），并将存款热转换成焊料可润湿的分层金属膜，以及使用高温焊料喷射印刷技术在UBM上印刷无铅焊料凸块。这项技术的商业应用可以降低电子行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进入成本提供给小批量应用。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，而且用环保的增材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.