Environmentally compliant alloys for aerospace electronics

人类并不是唯一衰老的实体。 所有材料的老化都是由组成其微观结构的原子和分子的原子运动，或与周围环境的化学反应引起的。 随着时间的推移，这些微小的运动和反应最终会改变材料结构，通常会削弱材料。用于在工程设备中将电子元件保持在一起的焊料合金材料的老化是主要关注的问题，特别是因为必须使用的环境立法焊料不能很好地老化-它们随着时间的推移而变弱，并且可能比铅（Pb）基材料行业更快地导致故障。 新的环保型焊料配方已经开发出来，在短期内具有成本效益和机械稳定性。为了使用这些材料组装高可靠性长寿命产品，其中故障成本高且故障风险是灾难性的，例如用于飞机控制系统，必须了解长期性能。该提案实现了对工业相关的Sn-Cu-Bi（锡铜铋）焊料合金的材料特性以及它们如何以及为什么随着年龄而变化的科学知识的创造。 然后，我们将把这些知识带到航空航天电子产品公司，以便他们在不久的将来需要完成向无铅电子产品的过渡时，能够使用最佳材料制造更高可靠性的产品。

Human beings are not the only entities that age. All materials age by the atomic movement of atoms and molecules that make up their microstructure, or by chemical reaction with the surrounding environment. Over time, these tiny movements and reactions end up changing the material structure, often weakening the materials. The aging of the solder alloy materials used to hold electronic components together in engineered devices is of major concern, particularly since the environmentally legislated solders that must be used do not age well - they weaken over time and can cause failures more quickly than the lead (Pb)-based materials industry has incorporated into historical risk models and system redundancies. New environmentally compliant solder formulations have been developed which are cost effective and mechanically robust in the short term. In order to use these materials to assemble high reliability long life products, where the cost of failure is high and the risk of failure are catastrophic, such as for airplane control systems, the long term properties must be understood. This proposal realizes the creation of the scientific knowledge on the material properties of the industrially-relevant Sn-Cu-Bi (tin copper bismuth) solder alloys and how and why they change with age. We will then bring this knowledge to aerospace electronics product companies, so that they can manufacture higher reliability products using the optimum materials when they need to complete the transition to lead-free electronics in the near future.