PCB production process seven: PCB production process step 5 | outer dry film
The sixth issue talked about the fourth step of the PCB production process丨hole metallization~PCB processThe content of the seventh issue is the introduction of the process of the outer dry film! The outer dry film is the seventh step of the PCB process, so what are the processes for it? And what is the purpose of this process? Let's analyze it together!
Outer layer dry film process introduction
The purpose of the outer dry film
After drilling and through-hole electroplating, the inner and outer layers have been connected. This process produces the outer layer dry film to provide graphics for the production of the outer layer circuit.
Introduction to pretreatment
① Purpose of pre-treatment: to remove pollutants on the copper surface and increase the roughness of the copper surface to facilitate the lamination process.
②Main raw materials: grinding and brushing.
lamination
①Purpose of film pressing: to make the dry film tightly adhere to the copper surface by hot pressing.
②Important raw materials: dry film (Dry film)
exposure introduction
①The purpose of exposure: to expose the required lines on the dry film through graphic transfer technology.
②Important raw materials: film
Development Introduction
①Development purpose: to wash off the area that has not undergone polymerization reaction with a developer, and the photosensitive part cannot be washed off due to polymerization reaction, and remains on the copper surface to become a resist film for etching or electroplating.
②Main production materials: Weak base (K2CO3)
