Via Tenting for PCBs
Most customers find their PCBs being thinner and use more surface mount components for their products. To solve this problem, EPCB use via tenting which can easily prevent excess solder in vias by covering them over with solder mask. By covering vias with solder mask material on the device side, the vias can be tented over to prevent solder from filling vias. This effectively keeps the low profile you need for your printed circuit board.
While via tenting can be an effective way to cover vias on your PCB, small amounts of fluid could remain trapped in the barrel of vias after the solder mask is applied. This can happen during the surface finish process, for example. As such, it is best to provide a small pinhole in the tent to allow any solution to escape the hole. However, the tent option remains cost effective and does not require additional processing steps during production.