The role of metallized holes in pcb circuit board manufacturers
PCB Assembly manufacturer china
TH is often referred to as a metallized hole. The pcb circuit board manufacturer coats the entire hole wall with metal to electrically connect the inner and outer conductive patterns of the two or more layers of the printed board. Hole plating processes have traditionally used electroless copper plating to deposit a thin layer of copper on the walls of the holes and then plate the copper to a specified thickness.
The process of pcb board manufacturers is to transfer graphics from one medium to another through image transfer using photosensitive materials. Taking the production of internal circuits as an example: first, the dry film is pressed on the substrate and then covered with a film. Next, the lighting is very different from the unlit area after exposure. (High Frequency PCB wholesales china)
For the Photo polymer dry film, the color of the illuminated area becomes darker, which means that it has hardened and then developed. If the original film is transparent, the dry film remains, while the original film is black and the dry film does not harden. . It has been shown. The substrate is then etched with a copper etching solution.