What are the requirements for PCBA welding process for PCB board?
When PCBA welding process, there are usually many requirements for the PCB board, and the board must meet the requirements to accept the welding process. Because in the process of PCBA processing, there will be a lot of special processes, and the application of special processes will immediately bring the requirements for the PCB board. If there are problems with the PCB board, it will increase the difficulty of the PCBA welding process, and eventually it may be Lead to welding defects, unqualified boards, etc.
Therefore, in order to ensure the smooth completion of the processing of the special process, and to facilitate the PCBA welding process, the PCB board must meet the manufacturability requirements in terms of size and pad distance.
1. PCB size
PCB width (including board edge) ≥ 50mm, ≤ 460mm, PCB length (including board edge) ≥ 50mm. If the size is too small, it needs to be made into a puzzle.
2. PCB edge width
Board edge width: ≥ 5mm, panel spacing: ≤ 8mm, distance between pad and board edge: ≥ 5mm
3. PCB curvature
Upward bending degree: 1.2mm, downward bending degree: <0.5mm, PCB distortion: maximum deformation height ÷ diagonal length <0.25
4. Mark point of PCB board
Mark shape: standard circle, square, triangle;
Mark size; 0.8~1.5mm;
Mark's material: gold-plated, tin-plated, copper-platinum;
Mark's surface requirements: the surface is flat, smooth, no oxidation, no dirt;
Mark's surrounding requirements: There should be no green oil or other obstacles within 1mm of the surrounding area, which is obviously different from the Mark's color;
Mark's position: more than 3mm from the edge of the board, and there should be no Mark-like vias, test points, etc. within 5mm of the surrounding area.
5. PCB pad
There are no through-holes on the SMD component pads. 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, causing the board surface to be uneven and unable to print the solder paste.
Only by strictly implementing the above standards can high-quality and compliant PCB boards be produced, so that the board can better accept other special processes, and give the PCB board life and inject the soul of function.