The Inner Layer Circuit Is Fabricated in The PCB Manufacturing Process

The production of inner layer circuits is a core link in PCB manufacturing. Its process mainly includes cutting the board, pre-treatment, lamination, exposure, development, etching, film removal and inner layer inspection, as follows:

Cutting: The original PCB substrate is cut to the required size for production to prepare for subsequent processes.

Pretreatment: Clean the surface of the substrate to remove contaminants such as oil stains and oxides, ensuring the smooth progress of subsequent processes.

Lamination: A dry film is attached to the surface of the substrate, and this dry film will transfer the image during the subsequent exposure process.

Exposure: Ultraviolet light is used to expose the laminated substrate to transfer the designed circuit pattern onto the dry film.

Developing: Remove the unexposed dry film part through the developing solution to leave the required line pattern.

Etching: Use etching solution to etch off the copper layer that is not protected by the dry film to form the inner layer circuit.

Film removal: Remove the remaining dry film to expose the inner layer of circuits.

Inner layer inspection: Use automatic optical inspection equipment (AOI) to conduct quality inspection on the inner layer circuits to ensure there are no defects such as open circuits or short circuits.