Roshanghias Ali, Bardong Jochen, Binder Alfred
Silicon Austria Labs GmbH, Europastrasse 12, A-9524 Villach, Austria.
Materials (Basel). 2022 Apr 11;15(8):2786. doi: 10.3390/ma15082786.
Glass frit bonding is a widely used technology to cap and seal micro-electromechanical systems on the wafer level using a low melting point glass. Screen printing is the main method to apply glass frit paste on wafers. Screen printing of glass frit paste is usually performed on less sensitive, less critical wafers, normally the capping wafer, because screen printing is a rough process involving the mechanical contact of the screen printing mesh and the wafer. However, for some applications in which contactless patterning of glass frit materials on the device wafers are preferred (e.g., 3D topographies, micro-lens and optics integration) jet dispensing could be a promising approach. Consequently, in this study, wafer-level jetting of glass frit materials on silicon wafers was proposed and investigated. The jetting parameters such as jetting distance, power and temperature were optimized for a glass frit paste. Additionally, the effect of jetted pitch size on the bond-line thickness was assessed. The wafers with jetted glass frit pastes were conclusively bonded in low vacuum and characterized. As a single-step (non-contact) additive approach, the jet printing of glass frit was revealed to be a straightforward, cost-effective and flexible approach with several implications for hermetic packaging.
玻璃料键合是一种广泛应用的技术，用于在晶圆级使用低熔点玻璃对微机电系统进行封装和密封。丝网印刷是在晶圆上施加玻璃料糊剂的主要方法。玻璃料糊剂的丝网印刷通常在不太敏感、不太关键的晶圆上进行，通常是封盖晶圆，因为丝网印刷是一个粗糙的过程，涉及丝网印刷网与晶圆的机械接触。然而，对于某些应用，其中在器件晶圆上对玻璃料材料进行非接触式图案化是优选的（例如，三维地形、微透镜和光学集成），喷射点胶可能是一种有前途的方法。因此，在本研究中，提出并研究了在硅晶圆上进行玻璃料材料的晶圆级喷射。针对一种玻璃料糊剂优化了喷射距离、功率和温度等喷射参数。此外，评估了喷射间距尺寸对键合线厚度的影响。将喷射有玻璃料糊剂的晶圆在低真空下进行最终键合并进行表征。作为一种单步（非接触）添加方法，玻璃料的喷射印刷被证明是一种直接、经济高效且灵活的方法，对气密封装有若干影响。
