Issues related to the implementation of Pb-free electronic solders in consumer electronics
Issues related to the implementation of Pb-free electronic solders in consumer electronics
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DOI：
10.1007/s10854-006-9021-7
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发表时间：
2007-03-01
影响因子：
2.8
通讯作者：
Frear, D. R.
中科院分区：
文献类型：
--
作者：
Frear, D. R.
消费电子应用是无铅化倡议和封装组装的主要目标，性能受到从共晶锡铅合金向无铅焊料合金转变的影响。本文概述了使用无铅焊料组装封装的关键问题和缓解可能性：高温回流、界面反应和可靠性。在回流无铅合金所需的高温下，吸收到包装中的水分可能会导致分层和失效。无铅焊料与镍和铜金属化的反应导致界面金属间化合物的厚度并不比锡铅合金厚很多，但由于无铅合金的强度增加，在机械载荷下提供了一条断裂的途径。讨论的可靠性问题包括热机械疲劳、机械冲击、电迁移和晶须。无铅合金倾向于改善热机械疲劳和电迁移性能，但不利于机械冲击和晶须生长。为了成功地将无铅合金应用到消费应用中，必须在设计上进行权衡。
Consumer electronic applications are the primary target of the Pb-free initiative and package assembly and performance is affected by the move from eutectic Sn-Pb to Pb-free solder alloys. This paper outlines the key issues and mitigation possibilities for package assembly using Pb-free solders: High temperature reflow, Interfacial reactions, and Reliability. At the high temperatures required to reflow Pb-free alloys, moisture absorbed into the package can result in delamination and failure. The reaction of the Pb-free solder with Ni and Cu metallizations results in interfacial intermetallics that are not significantly thicker than with Sn-Pb but provide a path for fracture under mechanical loading due to the increased strength of the Pb-free alloys. The reliability issues discussed include thermomechanical fatigue, mechanical shock, electromigration and whiskering. The Pb-free alloys tend to improve thermomechanical fatigue and electromigration performance but are detrimental to mechanical shock and whiskering. Design trade-offs must be made to successfully implement Pb-free alloys into consumer applications.