In the process of PCBA processing, there will be a lot of special processes, which will bring about the restrictive requirements for PCB board. If the PCB board does not meet the requirements, it will increase the difficulty of PCBA welding process, which may eventually lead to welding defects and unqualified boards. Therefore, in order to ensure the smooth completion of special process processing and facilitate PCBA processing, PCB board should meet the manufacturability requirements in terms of size and pad distance. Next, the requirements of PCBA processing on PCB board are introduced.
Printed Circuit Board requirements for PCBA processing
1. PCB size
PCB width (including board edge) shall be greater than 50mm and less than 460mm, and PCB length (including board edge) shall be greater than 50mm. If the size is too small, it needs to be made into panels.
2. PCB edge width
Plate edge width: > 5mm, panel spacing: < 8mm, distance between pad and plate edge: > 5mm
3. PCB bending
Upward bending degree: < 1.2mm, downward bending degree: < 0.5mm, PCB distortion: maximum deformation height ÷ diagonal length < 0.25
4. PCB mark point
The shape of mark: standard circle, square and triangle;
Size of mark; 0.8~1.5mm;
Mark material: Gold Plated, tin plated, copper platinum;
Mark's surface requirements: the surface shall be flat, smooth, free of oxidation and dirt;
Mark's surrounding requirements: there shall be no green oil or other obstacles within 1mm around, which is obviously different from Mark's color;
Mark position: more than 3mm away from the plate edge, and there shall be no mark like vias, test points, etc. within 5mm around.
5. PCB pad
There is no through hole on the pad of SMD components. If there is a through hole, the solder paste will flow into the hole, resulting in less tin in the device, or the tin will flow to the other side, resulting in uneven board surface and inability to print solder paste.
In PCB design and production, it is necessary to understand some knowledge of PCBA welding process, so as to make the product suitable for production. Understanding the requirements of the processing plant first can make the later production and manufacturing process more smooth and avoid unnecessary trouble.
This is the requirement of PCBA processing for PCB boards. Only by not slacking off in the production of PCB boards and producing high-quality and compliant PCB boards can the boards better accept other special processes, give the PCB board life and inject the soul of function.
The above is the introduction of PCBA processing requirements for PCB boards. I hope it can help you. At the same time, I want to know more PCBA processing information and knowledge.