Why do PCB need Vias Plugged with Resin

Via plugged with resin can solve the problems that green oil plug holes can't solve, but the characteristics of the resin used in this process need to overcome many difficulties in production in order to obtain good quality resin products. So why do PCB vias plugged with resin?

Traditional BGA may make vias between pads to the back for routing. If the BGA is too dense, it is impossible to route from the vias to the back, but you can drill directly from the pad to other layers for routing, then plug the vias with resin, and plate copper to form the pad. If only holes are made on the pads without resin plug holes, it will easily lead to short circuit on the back and virtual soldering on the front.

The PCB vias plugged with resin process includes drilling, electroplating, plugging, baking, and grinding. The holes are drilled and copper plated, then the resin is plugged and baked, and the resin is ground flat by grinding. Because the ground resin does not contain copper, an additional layer of copper is required to become a pad. These processes are all done before the original PCB drilling process, that is, the holes of the fortification holes are processed first, and then the other holes are drilled.

So what should be paid attention to in the resin plug hole? If the plug hole is not plugged properly, it will cause air bubbles in the hole. Because air bubbles easily absorb moisture, the PCB board may burst when passing through the tin furnace. In the process of PCB vias plugged with  resign, if there are air bubbles in the holes, the air bubbles will squeeze out the resin during the baking process, causing unevenness. At this time, defective products can be detected. The main reason for PCB explosion is moisture, so the resin plug via PCB that has just been received from the factory should be used in time, or be baked before use.

HoYoGo is an international, professional and reliable PCB manufacturer with our own production capacity, we are able to provide you with one-stop service for small, medium to high volume production. HoYoGo can provide HDI board, gold finger board, Hard gold, FPC, R-F, metal base, quick tun and PCBA.