Effects of drive air pressure, exhaust pipe length and deposition height on the morphology of Sn99.3Cu0.7 solder ball

As a uniform solder balls manufacturing technology, metal droplets jetting technology can realize controllable deposition of droplets, so it can apply to the production of solder balls array in BGA and CSP packaging. To study the influence parameters to the morphology of the solder balls, we developed an equipment based on the Pneumatic diaphragm drop-on-demand Technology. In this paper, we changed the air pressure and exhaust pipe length to analysis how they influenced the size and uniformity of the solder balls. Furthermore, we changed the deposition height to study how they influenced the morphology of the deposited solder balls. The results indicated that the size of the solder ball increased when the air pressure and exhaust pipe length elevated and the solder balls were uniform under different air pressure and exhaust pipe length. In addition, the surface of the deposited solder balls were smooth relatively, with no splash, no matter what the deposition height were.