Why reserve process edges for PCB production?
PCB process edge is also called working edge. It is a long blank board edge set for reserving track transmission position and putting Mark points in the mosaic when SMT is processed. The width of the process edge is generally about 5-8 mm.
In PCB production process, the reserve of process edge is very important for SMT patch processing. The process side is the part added on both or four sides of PCB board to assist SMT patch, DIP plug-in and welding walkboard. The main purpose is to assist PCBA production and processing. It is not a part of PCB board. PCB factory can remove it after PCBA production is completed.
Because the process side will consume more PCB sheets and increase the overall cost of PCB sheets, it is necessary to balance the economy and manufacturability in the design of PCB process side. For some special shaped PCB boards, the original PCB boards with two or four process edges can be simplified by splicing. In SMT patch processing, the track width of SMT patch machine should be fully taken into account when designing the patch method. For patches with a width of more than 350 mm, it is necessary to communicate with the SMT patch vendor's process engineer.
The main purpose of reserving process edge is that SMT Mounter track is used to clamp PCB board and flow through the mounter, so when electronic components too close to the track are absorbed by SMT Mounter suction nozzle and mounted on PCB board, they are prone to collision and can not complete the production process, so a certain process edge must be reserved. Its width is about 5 mm. Similarly, reserved process edges are also suitable for some plug-in components to prevent similar phenomena during wave soldering.
The smoothness of PCB process edge is also an important part of PCB production in PCB factory. When removing the edge of PCB production process, PCB factories need to ensure that the edge is smooth, especially for PCB boards with high assembly accuracy, any uneven edge will lead to the deviation of installation hole position, which will bring great trouble to subsequent PCB assembly and processing.
