Understanding the interaction between silver and lead-free solders in order to develop new solder alloys

了解银和无铅焊料之间的相互作用，以开发新的焊料合金

• 批准号: 2386306
• 金额: --
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2386306
• 关键词: Understanding; interaction; between; silver; lead

The printing of electrically conductive tracks on glass is an important technology in areas such as the automotive industry, where silver pastes are used to create the tracks for heated windscreens. The printing of conductive tracks on glass is also a key part of the manufacture of some photovoltaic systems (solar panels). After firing, such conductive networks need an electrical connection in order to operate, which is achieved by soldering. In former times, the solder alloys used contained lead, but realisation of the health and environmental concerns with this metal have led to the formulation of lead-free solders (such as SAC solders, based on the tin-silver-copper system). While these avoid the risks of using lead, the joint strength achieved is not reliably high enough, and it is critical for continued use of this technology that the problem is better understood, and that a solution is found.In this project we will explore the fundamental behaviour of the existing technology further to understand the key origin of the problems seen; these include microcrack formation in the joint region, and residual stresses after soldering, both of which contribute to reduced joint strength. We will fabricate and microscopically examine the joints produced between different solders and silver powders, to fully understand for the first time the interactions occurring and how they impact on the joint strength. Understanding the problem is just the first step however. Using the knowledge we gain, we will design new silver paste compositions to mitigate the problems. These novel alloys will be produced and processed at laboratory and trial scales, leading to validation of the alloy produced in accordance with industry standard methods. The work will involve close collaboration with the industrial partner, Johnson Matthey plc (a global science and chemicals company, with unique expertise in precious metals technology) through their technology centre in Sonning Common, Oxfordshire, UK and other sites, to trial the technology industrially.

在玻璃上印刷导电轨道在诸如汽车工业的领域中是一项重要技术，其中银膏用于产生加热挡风玻璃的轨道。在玻璃上印刷导电轨道也是制造某些光伏系统（太阳能电池板）的关键部分。在烧制之后，这种导电网络需要电连接以便操作，这通过焊接来实现。在过去，所使用的焊料合金含有铅，但认识到这种金属的健康和环境问题，导致无铅焊料的配方（如SAC焊料，基于锡-银-铜系统）。虽然这些避免了使用铅的风险，但获得的接头强度不够高，并且对于继续使用该技术来说，更好地理解问题并找到解决方案至关重要。在本项目中，我们将探索现有技术的基本行为，以进一步了解所看到的问题的关键根源;这些问题包括在接合区域中形成微裂纹以及焊接后的残余应力，这两者都导致接合强度降低。我们将制作并显微镜检查不同焊料和银粉之间产生的接头，以首次充分了解发生的相互作用及其对接头强度的影响。然而，理解问题只是第一步。利用我们获得的知识，我们将设计新的银膏组合物来减轻这些问题。这些新型合金将在实验室和试验规模下生产和加工，从而根据行业标准方法对生产的合金进行验证。这项工作将涉及与工业合作伙伴约翰逊Matthey plc（一家全球性的科学和化学品公司，在贵金属技术方面拥有独特的专业知识）通过其位于英国牛津郡Sonning Common的技术中心和其他地点进行密切合作，以在工业上试验该技术。