The thing that components close to the edge of PCB board is not conducive to automated assembly, mechanical stress concentration, easy damage during the turnaround, metallized holes and pads are easily pulled. Components are not allowed to be placed within 5 mm of the edge of the process, the clamping edge or the edge of the printed circuit board.
When placing components close to the edge of the printed circuit board, the long side of the component should be parallel to the edge of the printed circuit board. Chip ceramic capacitors near the edge of the panel, screws and sockets are prone to failure after aging at high temperatures or after a period of use.
A large amount of maintenance space should be left around the large components to facilitate the operation of the heating head of the equipment. When placing components close to the edge of a large component, the long side of the component should be parallel to the edge of the component.
The critical and valuable components such as close to the connector, mounting holes, slots, cutting of the board, gaps, corners and fastening areas and other high stress concentration areas, easy to cause solder joint fatigue or solder joint breakage.