STTR PHASE I: Development of Nanostructured Solder Materials

这一小型技术转移研究项目旨在推进无铅电子焊料的基础知识和性能。现有的无铅电子焊料由于微观结构的不稳定性，如粗化、晶界滑移和离子沿晶界的迁移，其热机械疲劳和电学特性限制了其性能。虽然纳米级的构建块已被证明可用于合金化并在聚合物中提供增强的性能，但这些工具尚未被用于控制金属中类似结构的动力学。利用纳米化学强化来控制无铅电子焊料合金在使用过程中的微结构稳定性和损伤积累是有可能的。本项目的目标是利用多面体低聚倍半硅氧烷(POSS)在焊料中提供1-10 nm级别的结构控制。这种控制将提供具有更高强度、耐用性和尺寸稳定性的焊料，用于航空航天、汽车、消费和微型机电系统中的互连。该项目的商业应用是改进的无铅电子焊料。识别合金中此类控制的机械和工艺限制，将有助于开发解决困扰商用和军用飞机、汽车、修复性牙科汞合金和相关修复体的金属疲劳、蠕变和使用寿命问题的解决方案。

This Small Technology Transfer Research project seeks to advance the fundamental knowledge base and performance of lead-free electronic solders. Current lead-free electronic solders are performance limited by their thermomechanical fatigue and electrical characteristics due to microstructural instabilities, such as coarsening, grain boundary sliding, and ion migration along grain boundaries in these alloys. While nanoscale building blocks have been shown to alloy and provide enhanced properties in polymers, these tools have not been applied to control the dynamics of analogous structures in metals. An opportunity exists to utilize nanoscopic chemical reinforcement to control both microstructural stability and damage accumulation during service for lead-free electronic solder alloys. It is the objective of this project to utilize polyhedral oligomeric silsesquioxanes (POSS) to impart structural control at the 1-10 nm level in solders. Such control will afford solders with higher strength, durability, and dimensional stability for use as interconnects in aerospace, automotive, consumer and micro-electromechanical systems.The commercial application of this project is in improved, lead-free electronic solders. The identification of the mechanistic and process limitations for such control in alloys will afford insights into the development of solutions for metal fatigue, creep, and service life issues which plague commercial and military aircraft, automobiles, restorative dental amalgams and related prosthetics.