Fundamental Investigation into the Mechanisms of Ultrasonic Assisted Single-Component and Multi-Component Low Temperature Sintering for the Assembly of Power Electronic Components

电力电子元件装配超声辅助单组分和多组分低温烧结机理的基础研究

• 批准号: 456662835
• 负责人: Dr.-Ing. Jens Twiefel
• 金额: --
• 依托单位: Institut für Mikroproduktionstechnik (IMPT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/456662835?language=en
• 关键词: Fundamental; Investigation; into; Mechanisms; Ultrasonic

Today's demands on power electronics have increased significantly, especially due to e mobility, so that the connection properties of proven processes such as soldering or bonding no longer meet future requirements. Especially the electrical and thermal conductivity as well as the increased process temperatures are challenges. As a result, silver compound sintering has become increasingly important in recent years. Here, a substrate and a chip are connected by a sintered intermediate layer of silver. Compared to traditional compounds, the properties of silver compound sintering are many times better. Why is this process not yet widely used? The reason are the high values of pressure and temperature required for the process. The process times are significantly longer than with other methods, so that currently only a batch process is economical; however, this leads to irregular joint qualities. This is where our research project comes in. We were able to show that in single chip assembly, the introduction of ultrasound into the bonding layer has a significantly positive effect on the formation of the bond, so that the process temperature, pressure and times were reduced. In addition, the process was extended by an alloying partner to form a new type of multi-component, ultrasonic-assisted process, which is introduced as Ultrasonic Transient Liquid Phase Sintering (UTLPS). Here, we were able to show first positive effects, too. The guiding questions for this research project are: Which mechanisms have a positive effect on the formation of compounds when using ultrasound? Is the diffusion process accelerated by ultrasound analogous to wire bonding? For this purpose, micro- and nanoscale sintering pastes will be developed first. Subsequently, the experimental investigation of the parameter influences on the joint quality will be carried out to enable a separation from the ultrasonic influence parameters. These are mainly the vibration amplitude, the power and the duration of the ultrasound. After the optimal ultrasonic direction (horizontal or vertical) has been determined, the time profile of the process is analyzed. Porosity and mechanical strength are measured to evaluate the joints and supplemented with other analysis methods. The investigations are performed on passive test chips and on active components (diode, IGBT, NTC). Here, the ultrasonic influence on the quality of the connection and the durability as well as possible damage to the components are examined. The research project is concluded with the model-based description of the mechanisms of ultrasonic assisted silver compound sintering. By answering the key questions, silver compound sintering will be significantly improved. This opens up this bonding technology for many more applications.

如今，对电力电子设备的需求显著增加，特别是由于电子移动性，因此焊接或粘合等成熟工艺的连接性能不再满足未来的要求。特别是导电性和导热性以及增加的工艺温度是挑战。因此，近年来银化合物烧结变得越来越重要。这里，衬底和芯片通过烧结的银中间层连接。银化合物的烧结性能比传统化合物好很多倍。为什么这个方法还没有被广泛使用？原因是该过程所需的高压力和温度值。加工时间明显长于其他方法，因此目前只有批量加工是经济的;然而，这会导致不规则的接头质量。这就是我们的研究项目的用武之地。我们能够证明，在单芯片组装中，将超声波引入键合层对键合的形成具有显著的积极影响，从而降低了工艺温度、压力和时间。此外，该工艺还通过合金化伙伴进行了扩展，形成了一种新型的多组分超声辅助工艺，称为超声瞬时液相烧结（UTLPS）。在这里，我们也能够显示出第一个积极的影响。该研究项目的指导性问题是：使用超声波时，哪些机制对化合物的形成有积极影响？超声波加速的扩散过程是否类似于引线键合？为此，将首先开发微米和纳米级烧结浆料。随后，将进行参数对接头质量的影响的实验研究，以实现与超声影响参数的分离。这些主要是超声的振幅、功率和持续时间。在确定最佳超声方向（水平或垂直）后，分析该过程的时间曲线。通过测量孔隙率和机械强度来评估接头，并辅以其他分析方法。调查进行无源测试芯片和有源元件（二极管，IGBT，NTC）。在这里，超声波对连接质量和耐用性的影响以及对部件的可能损坏进行了检查。最后，对超声辅助银化合物烧结机理进行了模型化描述。通过对这些关键问题的回答，将显著提高银化合物的烧结性能。这为更多的应用开辟了这种粘合技术。