Industry news

PCBA welding processing requirements

2022-04-14

PCBA welding processing requirements

Professional analysis of PCBA process

PCBA welding processing usually has many requirements for PCB board, which must meet the welding requirements. So why does the welding process require so many requirements for circuit boards? Facts have proved that there will be many special processes in the process of PCBA welding, and the application of special processes will bring requirements to PCB.
If the PCB board has problems, it will increase the difficulty of PCBA welding process, and may eventually lead to welding defects, unqualified boards, etc. Therefore, in order to ensure the smooth completion of special processes and facilitate PCBA welding processing, PCB board must meet the manufacturability requirements in terms of size and pad distance.
1. PCB size the width of PCB (including the edge of circuit board) must be greater than 50mm and less than 460mm, and the length of PCB (including the edge of circuit board) must be greater than 50mm. If the size is too small, it needs to be made into panels.
2. The width of PCB board edge is more than 5mm, the board spacing is less than 8mm, and the distance between base plate and board edge is more than 5mm.
3. PCB bending: upward bending: < 1.2mm, downward bending: < 0.5mm, PCB deformation: maximum deformation height ÷ diagonal length < 0.25.
4. PCB mark point shape: standard circle, square and triangle; Mark size: 0.8 ~ 1.5mm; Mark materials: gold plating, tin plating, copper and platinum; Mark's surface requirements: the surface is flat, smooth, free of oxidation and dirt; Requirements around mark: there shall be no obstacles such as green oil that is obviously different from the color of the sign within 1mm around; Mark position: more than 3mm from the edge of the plate, and there shall be no through hole, test point and other marks within 5mm.
5. There is no through hole on PCB pad and SMD component pad. If there is a through hole, the solder paste will flow into the hole, resulting in the reduction of tin in the device, or the tin flows to the other side, resulting in uneven board surface and unable to print the solder paste. In PCB design and production, it is necessary to understand some PCB welding process knowledge in order to make the products suitable for production. First of all, understanding the requirements of the processing plant can make the subsequent manufacturing process more smooth and avoid unnecessary trouble.
The above is the requirements of PCBA welding processing for PCB board. In the production of PCB boards, we should not slack off. Only by producing high-quality PCB boards, can PCB boards better accept other special processes, give PCB boards life and inject the soul of function.