PCB-assembling pcb-assembly pcb-assembler ems electronic manufacturing service electronic manufacturing assembling assembly research research and development pcb-layout pcb-design pcb-development hardware development software development circuit design circuit simulation selectiv soldering reflow soldering reflow oven automatic assembling manual assembling special manufacturing customized solutions customised solutions soldering robot aoi automatic optical inspection load free pattern cutting ic-test in-circuit-test assembly line paste printer tht-assembly tht-assembly smd-assembly traceability laser tampon print pcb-varnishing