Since the traditional lead components of Through Hole Assembly Electronic Services have been the backbone of the electronics industry for many years, "through-hole" assembly still plays a large role despite the continuous development of surface mount technology (SMT), miniaturization and complexity. In fact, through-hole component elements are typically present even on primarily surface mount components.
As far as possible, the spacing of the positioning holes and the distance between them and the components are larger, and the size of the positioning holes is standardized and optimized according to the insertion equipment; do not plate the positioning holes because the diameter of the plating holes is difficult to control.
As far as possible, the positioning holes are also used as mounting holes for the PCB in the final product, which reduces the drilling process during production.
The test circuit pattern can be arranged on the waste side of the board for process control. This pattern can be used to monitor surface insulation resistance, cleanliness and solderability during the manufacturing process of Through Hole Assembly Electronic Services.
For larger boards, a path should be left in the center to support the board at the center position during wave soldering to prevent the board from sagging and solder sputtering, which helps the board to be soldered consistently.