If you are reading this blog post right now it probably means that somewhere in your online adventures you recently encountered either the phrase “chem etch” or “photofab” (probably in the context of do-it-yourself computer design or jewelry making) and do not understand what those phrases mean given the context. This is nothing to be ashamed of; in fact the phrase stands for chemical etching, a little known process outside of technical or industrial circles, but one that has immense import for modern society and the manufacturing industry in America today. For many people it might even be more surprising if they did know what those terms meant automatically.
In short, chemical etching is a method of cutting into metal by using acids. This is an ancient technique that has been used on everything from swords and armor to computer chips and CT scanners in hospitals. In modern times companies tend to prefer photofabrication (“photofab”) as their primary chem etch technique, a process that involves using light reactive masking agents called a “resist” or “mask” to shield the metal from the acid. Technicians then print a design onto the masking agent and expose the whole thing to light, hardening the mask in the areas not covered by the design. A simple bath in water will cleanse the unwanted masking agent away and leaving the spaces to be cut by the acid clear of any obstruction, and then the whole sheet is sprayed with chemicals to eat away the metal before getting neutralized and washed again one last time.
In general chem etch is used to manufacture precision parts for computers, such as microchips, or other very small metal designs like an ultra-fine mesh or radio frequency shields. Because acid is used instead of heavy machinery the finished products tend to be very high quality and free of most errors, making them ideally suited for very high tech equipment, which may help explain why you are starting to see the phrases pop up more often these days as technology continues to rapidly expand.