PCB Photoimaging Process Introduction

What is PCB photoimaging process? Many people are not very familiar with this process. A PCB copy board engineer will give you a brief introduction to what PCB photoimaging process. The PCB photoimaging process is a method of exposing the photoresist coated on the substrate of the printed circuit board to change its hardness, adhesion, solubility and physical properties, and then developing an image.

There are two main types of photoresists for photochemical image transfer in printed circuit board manufacturing. One is photoresist dry film (referred to as dry film), and its product is a photoimageable photosensitive ink. The other type is liquid photoresist, which includes ordinary liquid photoresist and electrodeposited liquid photoresist (abbreviated as ED resist). ED resist is a water-based emulsion.

Photoresist is the cornerstone of the modern printed circuit industry. The photoresist dry film has the characteristics of simple process flow, low requirements for cleanliness and easy operation. Since its inception, it has been quickly welcomed by printed circuit companies. After several improvements and developments, it now occupies most of the photoimaging technology in printed circuit manufacturing and has become a mainstream product.

Before the appearance of dry photoresist film, liquid photoresist was an important material for imaging technology at that time. Because the thickness is not easy to control in the application, the slow operation speed, and the board surface defects caused by the cleanliness and handling of the process environment, limit its use. After the advent of dry film, photoresist was once replaced by dry film technology. However, in recent years, with the development of electronic products in the direction of thin, small and dense, printed circuit companies have faced pressure to reduce prices, the emergence of new high-resolution liquid photoresists, and liquid photoresists. The coating equipment of the agent has the capability of continuous mass production, which has regained its development in the field of printed circuit photo-imaging.