Design and optimization of a pneumatic DOD solder ball 3D printing system

This work is to set up a solder 3D printing system for solder ball printing. Effect of major factors that may affect the performance of the system has also been investigated. Therefore, performance of the system was optimized. A pneumatic DOD (drop-on-demand) solder 3D printing system was set up for solder ball printing. The effects of major factors were studied by control variable method, such as peak pressure, supply pressure and signal pulse width. Formation of liquid solder droplets during printing was simulated by 2D VOF (volume of fluid) two-phase flow model. The built DOD solder ball 3D printing system can prepare solder balls with good sphericity and uniformness. The formation of solder balls is split into four stages, ejection, necking of molten solder, fracture of liquid thread and formation of droplet. It also shows the peak pressure in ejection chamber increases alongside the rise of supply pressure and signal pulse width. The system provides a more cost-efficient solution for solder-based interconnections.