The reason for the shrinkage of holes in the PCB board drilling process is
that the copper clad board is drilled in the PCB process. Due to the heat, the
drilled holes shrink and the holes are smaller than the drill bit.
The reason for the occurrence of shrinkage cavities is mainly that the
substrate is not completely cured, and the subsequent processing of the PCB
board is repeated by the heat generated holes, which is often encountered in the
application of the insulating board. Since the shrinkage hole affects the
assembly of the subsequent electronic components, it is necessary to prevent the
substrate from being incompletely cured, resulting in a shrinkage phenomenon of
the PCB process. After receiving complaints about quality problems from users,
it can be solved by increasing the degree of curing of the substrate.
Incomplete curing of the substrate may also cause oblique holes in the
drilling process of the PCB board.
Since the thickness of the copper clad laminate is relatively thin, the
oblique hole is not easily observed, so the inclined hole mainly appears on a
relatively thick insulating plate. During the drilling process, the drill bit
does not pass vertically through the substrate, but obliquely through the
substrate, seriously affecting product use. The cause is due to incomplete
curing of the substrate.
Basic curing is not the main problem that affects the hole in the PCB board
drilling process. Although it seems to be a small problem, it will increase the
difficulty of assembly of the PCB board, and the quality may be greatly
discounted, so the basic curing is improved. Degree is very important!