All of these problems can cause the solder shield to detach from the circuit board and eventually lead to corrosion of the copper circuit. Poor insulation due to thin solder resistance layer can cause short circuit due to unexpected conduction/arc.
That is: the actual out of the board is the circuit diagram to the right edge line as the reference line to the right after 180 degrees of the page. Pay special attention when there is a blank space! Otherwise the board is useless!
That is to say, ordinary PCB substrate materials at high temperature, not only produce softening, deformation, melting and other phenomena, but also show a sharp decline in mechanical and electrical characteristics.
There are many factors causing the coating cavity, the most common is PTH coating cavity, by controlling the relevant process parameters of the potion can effectively reduce the generation of PTH coating cavity. But other factors can not be ignored, only
the effect is not ideal, and the use of plasma to drill dirt and dent, can obtain better roughness of the hole wall, conducive to the hole metallization electroplating, and at the same time has the "three-dimensional" dent connection characteris...
A blind by-pass hole and a microvia hole are created in the pad to allow direct wiring to another layer. Because these bypass holes are small and blind, they do not suck up much solder, resulting in little or no effect on the amount of tin in the solder j
The ejected pumice powder particles may enter the pore at a high rate and wash away the catalytic layer particles. On the other hand, the graphite process seems to tolerate pumice stucco treatment.
he natural bubble is caused by the reaction of hydrogen in the chemical copper solution, or the cathode to produce hydrogen or anode to produce oxygen in the electroplating solution.
The size of the digital circuit output current Ioh pulled from the power supply at high voltages and the current Iol injected at low voltages is generally different, that is, Iol > Ioh.
Electronic products are very afraid of damage, if you need to use electronic products in harsh environments. It is strongly recommended to coat the PCB board with three anti - adhesive, which will form a protective coating.
Increase the dielectric constant of PCB board, which can prevent the high frequency parts such as the transmission line near the board from radiating outward.
Each circuit layer in the multilayer circuit board is pressed together by the action of semi-cured sheet; Depending on the circuit design, some areas of the semi-cured sheet need to be cut and then pressed together.
