Via hole, also known as the conduction hole, in order to meet customer requirements, the conduction hole must be plug hole, after a lot of practice, change the traditional aluminum plug hole process, with a white net to complete the board surface solder and plug holes. The production is stable and the quality is reliable.
The via hole of the via hole serves to connect the lines to each other. The development of the electronics industry also promotes the development of the PCB. It also imposes higher requirements on the printed circuit board manufacturing process and SMT surface mount technology. Via hole plug hole process came into being and should meet the following requirements:
1. The copper in the via hole is enough, and the solder resist can be plugged;
2. There must be tin-lead in the via hole, and there must be a certain thickness requirement (4 microns). There must be no solder-resist ink in the hole, causing the hole to hide tin beads.
3, the conduction hole must have a solder mask plug hole, opaque, there must be tin ring, tin beads and flat and other requirements.
With the development of electronic products in the direction of “light, thin, short, and small”, PCBs have also developed to high density and high difficulty. Therefore, a large number of SMT and BGA PCBs have appeared, and customers require plug holes when mounting components. Five roles:
1, to prevent PCB over-wave soldering when the through-hole through the component through the hole caused by a short circuit; in particular, we put the via hole on the BGA pad, you must first do the plug hole, and then gold-plated treatment, easy to BGA welding.
2, to avoid flux residue in the through hole;
3, electronic factory SMT surface mount and component assembly is completed after the PCB on the test machine to vacuum to form a negative pressure to complete;
4. Prevent surface solder paste from flowing into the hole to cause imaginary welding and affect mounting.
5, to prevent the solder ball popping during wave soldering, resulting in a short circuit.