4-layer-pcb
4-layer-pcb with 2.5mil pad gap. and line to line with 2.3mil spacing. we can porduce these kinds small spacing 4 layer pcb boards. and the smallest via holes size are 3 mil. PCB quality are great!
If you need 4 layer small spacing pcb boards. please send us your pcb gerber files. and processing requirement. let’s have a quote.