Correcting factor of solder paste volume calculation for Pin-in-paste technology

In this paper, a new method for calculating the amount of solder paste required for Pin-in-paste technology is presented and compared to a widely used explicit expression from literature. This work is the continuation of the paper presented in SIITME2013. The optimal shape of the solder profile for Through-hole components is calculated with Surface Evolver; and the necessary volume is determined based on the profile calculation. The boundary conditions of the Surface Evolver calculations are the following: the solder wets until the edge of the solder pads and the contact angle is equal to the wetting angle. In the experiment, the volume is determined for different through-hole diameters and for various widths of solder pads (annular rings). Contrary to the previous paper (in which only circular lead was investigated), the calculations were extended including components with rectangular cross-sectional leads. The determined volumes were then compared to volumes calculated based on the literature expression; and correction factors were defined for both circular and rectangular leads.