The methods of this method are fairly simple, and The important thing would be to plug the pores and clean up the plugged solder mask. A lot more overall flexibility and trustworthiness: Double-sided PCB comes with the two the highest layer and base layer, so You may use The underside https://connernrstu.actoblog.com/32009642/four-layer-inner-and-outer-layers-2oz-copper-thick-pcb-circuit-board-things-to-know-before-you-buy