subject: Chemical Milling And Etching Vs Other Processes [print this page] Chemical etching (also known as chemical milling) is an industrial manufacturing process which uses acids, bases, or other chemicals to remove as well as dissolve select unwanted areas of materials such as metals, semiconductor materials, or glass. The process involves using a masking agent to cover the metal part in the desired shape and etch away the remaining exposed areas. Some of the commonly used masking materials are elastomers and plastics. In many instances, a photoresist is used; in which case, the chemical milling process is known as the photochemical milling process. The process is especially ideal for the production of small extremely fine components from thin gauge metal, since other manufacturing processes might be unable to create as delicate features.
Chemical milling is typically offered as an alternative to various manufacturing techniques for the production of thin gauge precision parts, including punching, stamping, water jet cutting, and laser cutting. The expenses required for chemical milling are significantly less than what is needed for stamping and punching. Stamping and punching require the fabrication of expensive hard tooling to facilitate the operation, unlike chemical milling that does not require any tooling. Even in the case of photochemical milling that requires a phototool, the cost of the phototool is much less than hard tooling. In addition, the phototools are only exposed to light and consequently do not undergo the wear associated with the tooling used in stamping.
The inexpensive nature of chemical milling, as well as the speed with which it can turn around a part makes it an ideal option for rapid prototyping. Using this process, a component can be manufactured in a matter of hours after receiving the part print. Another advantage of chemical milling over other conventional manufacturing processes is that it preserves dimensional tolerances with ease. The process does not produce any burring or sharp edges and hence removes any need for additional machining and finishing services.
Furthermore, certain components that are extremely fragile and complex can only be manufactured by chemical milling since it is not possible for conventional manufacturing processes to produce them. Unfortunately, a major disadvantage to chemical milling is its ability to work primarily with only thin gauge components, however, it is sometimes used in thick components to remove shallow layers of materials in lieu of a grinding operation. This operation is primarily used in the aerospace industry.
