Long with the electronic products to the "light, thin, short, small" direction, PCB with high density, difficult development, so plenty of PCB of SMT, BGA, and at the time of the SMT components customer requirements plug hole, there are five main functions:
(1) to prevent PCB from passing through the waveguide hole through the element surface and causing a short circuit;In particular, when we put the hole on the BGA welding plate, we must first make the plug hole and then the plating process, so as to facilitate the welding of BGA.
(2) avoid the flux residue in the guide hole;
(3) after the surface mount of the electronics factory and the assembly of components are completed, the PCB shall vacuum on the test machine to form negative pressure to complete:
(4) prevent the surface solder paste flowing into the hole to cause virtual welding and influence the paste;
(5) prevent the tin beads from popping up during the wave soldering, causing a short circuit.