This document contains tags and metadata for various printed circuit board (PCB) products and manufacturing processes, including: eight layer HDI mobile boards, double sided HASL finished boards, 2 layer aluminum boards, 12L multilayer PCBs, heavy copper PCBs, 6 layers ENIG PCBs, 4 layers gold finger PCBs, PCB via stubs, methods for copying PCB boards, company information like about us and contact details, technology, quality assurance, double sided immersion silver, certificates, precision phosphor copper anode, multilayer hole processes, surface coatings advantages and disadvantages, international standards, conduction/via/plug holes, FR4 4 layer boards, FPC flexible board