What is etching process?by using carbon steel as example,explain the purpose of this process.?

Question

What is etching process?by using carbon steel as example,explain the purpose of this process.?

Answer 1

Usually a photosensitive chemical is sprayed onto the surface to be etched.  Then a mask is applied with the graphic or words to be etched.  The process may be photo-positive or photo-negative, so the design in the mask may be a positive image or a negative image.

The mask is applied over the photo-resist chemical and light is shined on the surface.

The exposed photo-resist chemical is washed off and the unexposed chemical remains.

Etchant chemical (i.e. acid, strong oxidizing agent, etc.) is applied to the metal and it will  only attack the places where the photo-resist chemical was washed away (which is in the shape of the design to be etched).

After a few minutes the metal is rinsed off and the remaining photo-resist material is either scraped off, or another chemical is used to remove it (that won't etch the metal).

The purpose of this process is to permanently mark metal materials with things like serial numbers, identifying numbers, model numbers, fancy designs, etc.

Printed circuit boards are also etched.  The copper is etched using a chemical such as ferric chloride.

Integrated circuits are etched in multiple layers using micro photolithography.

.

.