Wire frame pattern in PCB processing: generally, the wire frame pattern of electronic equipment must be marked on the wire frame layer. The wireframe pattern includes wireframe marking, electronic device label, optical rotation and IC 1-pin label. High density, can be used in short intervals, simplified symbol use, in special cases can omit the number of components. Pay attention to the OSP pad coating: simplify the wire mesh thickness to not exceed the pad thickness, otherwise it is easy to pick up components from the side.
Safety precautions in the processing of circuit board: when operating the equipment, the actual operator must pay attention to the actual operation, do not operate the equipment by hand, so as to avoid accidents. Do not use brute force and rough handling when removing the feeder. Do not remove the feeder when the placement head is above the feeder. It is strictly forbidden to check the machine during operation. If a running computer fails, you must check it when you stop it.
There are two ways to apply solder resist in PCB processing, one is liquid screen printing solder resist and the other is light resist flux. The size accuracy of solder mask opening window depends on the process level of PCB manufacturer. When using the solder resist sizing method of liquid screen printing ink, the window opening and ventilation specification of solder mask must be 0.4 mm larger than that of pad. The window size of the solder mask layer must be 0.15 mm larger than the pad size when using the bare solder resist coating process. For the detailed part of the solder mask, the screen printing technology requires a distance of 0.3 mm, while the photolithography technology requires a distance of 0.2 mm.
