Photo Courtesy of KEMAC Technology Inc.
Perhaps the most productive way of etching metals it through photo etching. In many ways it is similar to chemical etching, but there are some major differences in the process. This is mainly how the coating applied to the metal is formed into the correct pattern. Both are good alternatives to mechanical etching, and both have their benefits.
In chemical etching, the coating is applied and then must be cut. For the pieces that are to be treated the coating must then be removed. Once the coating is removed, the chemical can be placed. This can be a difficult process, and if done incorrectly will have to be repeated. However, in photo etching, this process is much simpler. In this case, the coating applied is a UV-sensitive photoresist. When exposed to light, it is able to be developed and hardened into the desired shape and pattern. The chemical can then be applied to the entire piece. The chemical is able to remove the unexposed layer making contact with the parts that are meant to be etched. The hardened sections of the photoresist will remain to protect the areas that aren’t meant to be etched. Shortly, after the metal has been corroded to the correct level in both the chemical and photo etching processes, the acid and remaining coatings can be removed and the perfectly etched piece is revealed.
The only difficulty when using photo etching is it should only be used on thicknesses ranging from .001” to .080”. The process is most effective within this range. Photo etching can be done on parts with diameters ranging from .020” to 24” X 26”. Using this method on metals makes it possible to create products with high tolerances and precise shapes. They can also be made quicker and inexpensively, making it a great option for many industries.