You will decide this by the sort of material your flex PCB involves. In addition to supplies, flexible PCBs can be found in numerous manufacturing grades. PCB surface area procedure is to address the PCB floor with a protective layer to circumvent copper oxidation, corrosion and to boost solderability, dependability https://8-layerthickcopperpowerpc05947.mybuzzblog.com/10610997/5-tips-about-goldfinger-pcb-for-electronics-industry-you-can-use-today