Vippo PCB refers to all of the PCB board holes that press against the pads (via in-pad plated over PCB). Generally speaking, the vippo’s diameter is limited to 0.5mm. A weak connection between the device as well as the pad & virtual soldering would happen if the solder paste did not flow into the hole while placement or the flux did not flow into the hole to produce gas during heating.
The solder ball or ink pads in the holes, which is the so-called oil blast phenomenon, is the hardest thing to handle for the vippo PCB plug hole. Some PCBs clients are very particular about the pad and how the solder mask should look. One of them is PCB fabrication. Vippo is required to fill the hole, and the problem of oil explosions after curing or spraying tin, which resulted in the problems of solder mask on the pad & solder ball in the hole, was the hardest thing to handle when we were manufacturing PCB in the past. Curing or spraying tin is a process of the solvent volatilization of the plug-hole ink and the shrinkage of the resin. Therefore, improper control is most likely to cause tin beads or oil explosions in the hole.
There are several steps involved in making printed circuit boards:
- Through-hole plating
- Selective plugging (fill)
- Polishing (planar)
- Plated over (cap)
Different schemes for various quality faults have been developed after extensive testing, data analysis, & defect analysis. The research outlines the development of each process and achieves outstanding results.