Three-dimensional modelling of solder droplet impact onto a groove

• Published in: Journal of physics. D, Applied physics Applied physics, 2008-12, Vol.41 (24), p.245503-245503 (12)
• Main Authors: Tian, D W, Tian, Y H, Wang, C Q, Hang, C J
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Microelectronic fabrication (materials and surfaces technology); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/41/24/245503

Solder jet technology is widely applied in MEMS packaging. To optimize and control the packaging process, a three-dimensional model was developed to investigate the process of solder droplet impact on a groove with two rectangular pads. In this model, a volume-of-fluid (VOF) method was explored to track the droplet surface and to account for the presence of inertia, viscosity, gravitation, surface tension and wetting effects. The phenomenon of bubble formation was investigated. The numerical model was validated with visualizations of the transient impact processes. The results show that the deformation along the groove is greater than that along the pads. The interactions of the solder gas and solder pad have a significant influence on the droplet shape. The kinetic energy, surface energy and viscous dissipation are the main energy components that influence the impact dynamics, whereas the gravitational potential energy can be neglected. The influences of the impact velocity, droplet size and groove angle on the droplet impingement were quantitatively evaluated.