Profile: GESP Technology Co. Ltd. is a manufacturer PCB fabrication and PCB assembly. We offer a complete PCB supply solution. such as PCB layout, PCB design and PCB assembly. We provide quick-turn custom PCB prototyping services. Our multi-layer printed circuit board will become the traces, pads, and metal ground put down with laser direct imaging (LDI). The layers checked for flaws by an automated optical inspection before lamination. The panel put into a copper plating bath with sulfuric acid and copper sulfate. The conductive pattern and drill holes are now visible. As more electricity flows through it. copper deposited on the conductive surface of the board until it is about 1 mil thick. The board is then removed and placed into a tin bath that acts as an etching barrier.