1. Spacing between wires

For the processing capacity of Shenzhen PCB manufacturers, the minimum distance between wires should not be less than 3mil. The minimum line distance is also the distance from line to line and from line to pad. From a production perspective, if conditions permit, the larger the better, with a common one being 10mil.

2. Pad aperture and pad width

In terms of the processing capacity of PCB manufacturers in Shenzhen, if the pad aperture is mechanically drilled, the minimum should not be less than 0.15mm, and if laser drilling is used, the minimum should not be less than 4mil. The aperture tolerance varies slightly depending on the plate, and can generally be controlled within 0.05mm. The minimum width of the welding pad should not be less than 0.2mm.

If copper is laid on a large area, there usually needs to be an internal shrinkage distance of 20mil from the edge of the board. In the PCB design and manufacturing industry, in general, due to mechanical considerations of circuit board finished products, or to avoid situations such as curling or electrical short circuits caused by exposed copper sheets at the board edges, engineers often shrink large areas of copper blocks by 20mil relative to the board edges, instead of always laying copper sheets to the board edges.

There are many methods for dealing with copper skin shrinkage, such as drawing a keepout layer on the e