Spray Chemical Milling
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Photo Chemical Milling is a process for manufacturing small parts from flat sheets of metal by chemical etching. The process is begun by cleaning the metal, then applying a thin light activated coating called a photoresist. The coated metal is exposed to a light pattern, and chemically developed, which removes the portion of the coating which has not been exposed to light (a negative working photoresist) or the portion of coating which has been exposed to light (a positive working photoresist). The metal sheet is then put through a chemical etchant etchant, (most common is Ferric Chloride solutions) which etches the area not protected by the photoresist. The remaining photoresist is then stripped off, leaving the part ready to be used, or continued to be formed. Some products that it is used on is washers, gaskets, heat sinks, ladders, plates, jewelry and many more products. Biggest use of photochemical milling today is in production of lead frames for semiconductors. It is used for prototypes and for ease of change for mass products. It can be good for dimensional tolerances, it doesn’t create burrs or sharp edges. Parts can be produced by Photo Chemical Milling from virtually any commercially available metal or alloy of any hardness. Metals include aluminum, brass, copper, inconel, manganese, nickel, silver, steel, stainless steel, zinc and titanium. This type of milling can be quick and easy for new parts. It can make a part in hours after receiving the drawing.

