Metal photo etching, also known as chemical etching or photochemical machining, is a subtractive manufacturing process that uses a photoresist and chemical etchants to selectively remove material from a metal surface. The process begins with a metal sheet, typically made of stainless steel, copper, brass, or aluminum, that is cleaned and coated with a light-sensitive photoresist.
A photographic mask, which contains the desired design or pattern, is then placed over the photoresist-coated metal sheet and exposed to ultraviolet light. The exposed areas of the photoresist harden, while the unexposed areas remain soft. The metal sheet is then developed, which removes the unexposed photoresist and exposes the bare metal underneath.
Next, the metal sheet is placed in a chemical etching solution, which selectively removes the exposed metal areas, creating the desired design or pattern. The depth of etching can be controlled with precision, allowing for fine details and tight tolerances. Finally, the remaining photoresist is stripped away, leaving behind a clean, etched metal part.
Applications of metal photo etching