1. Spacing between wires:
According to the production capacity of PCB manufacturers, the spacing between traces must not be less than 4MIL. Line spacing, also known as the distance between lines and between lines and solder pads. So, from our production perspective, of course, the larger the better if conditions permit. The usual 10MIL is quite common.

2. Pad aperture and pad width:
According to PCB manufacturers, if mechanical drilling is used, the pad aperture must not be less than 0.2mm, and if laser drilling is used, it must not be less than 4mil. The aperture tolerance varies slightly depending on the type of plate used. Generally, it can be controlled within 0.05mm. The width of the solder pad shall not be less than 0.2mm.

3. Spacing between solder pads:
According to the processing capability of PCB manufacturers, the distance between solder pads should not be less than 0.2mm.
4. Distance between copper sheet and board edge:
The distance between the charged copper sheet and the PCB board edge should not be less than 0.3mm. If it is a large area of copper laying, there is usually a need for an inward distance from the board edge, which is generally set to 20mil. In general, for mechanical considerations of finished circuit boards or to avoid situations such as curling or electrical short circuits caused by exposed copper sheets on the board edges, engineers often shrink large areas of copper blocks by 20mil relative to the board edges, rather than continuously laying copper sheets to the board edges. There are many methods for treating copper skin shrinkage. For example, draw a keepout layer on the edge of the board, and then set the distance between copper laying and keepout.