Photo Etching vs. "the Others"
Photochemical machining is the industry's preferred moniker for this metal fabrication process. It is also readily called photo or chemical etching, The process derived from the then-nascent printed circuit board industry in the 1950s. The fabrication steps are nearly identical.
More recognized processes such as metal stamping and punching utilize hardened steel tools to shape metal parts and have long histories in metal fabrication. Plasma, laser and water jet cutting utilize directed energy to shape parts. And, wire EDM uses a wire electrode to burn away metal. In these cases the evolution of CNC (computer numerical control) in the 1970s allowed part geometries to be programmed directly into cutting machines.
The most "traditional" processes, stamping and punching, are sort of "brute force" processes, shearing metal using powerful presses. Plasma, laser and EDM rely on intense energy, literally burning their way through metal. Waterjet is sort of the "hot knife through butter" option, but you definitely wouldn't want to get in the way of a pressurized stream of water that can cut through an inch of steel!
Photo etching, in contrast, would be like running a sheet of metal through your dishwasher and then taking out a sheet of parts.
"Stress Free" Precision Metal Fabricating
Photo etching is deemed a "non-conventional" method that fits alongside plasma, laser, waterjet and wire EDM for manufacturing many types of metal parts.
The more well-known fabrication methods have their own sets of undesirable side effects. Stamping and punching produce burrs from the shearing forces, and often cause "cold working" of the metal that may need to be alleviated by annealing. Plasma, laser and wire EDM impart significant heat into the work material. Plasma operates at about 25000 deg F; laser and EDM typically between 2500 and 5000 deg F. In these cases, the side effects of the intense heat include what are called "heat-affected zones" or recast layers that need to be rectified by secondary processes.
Photo etching completely avoids all of these side effects. The maximum temperature metal is exposed to in etching is 165 deg F. In addition, etching is particularly capable with very thin materials (routinely down to .001")--which is beyond what is in the comfort zone for the other processes. Etching is also very capable with regard to both reflective and thermally conductive metals such as aluminum and copper, which can be problematic for lasers in particular..
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The photo etching process is used for fabricating metal parts for many different industrial applications including sensors, shields, retainers, flat springs, strain gauges, filters, screens, grids, shims, gaskets and more. For electronics, etching is used to produce a host of metal components used in RF, microwave and wireless applications, as well as lids and leadframes for microelectronics packaging. Photo etched direct bond copper is increasingly used in power electronic applications, particularly in wireless devices. It is also used to produce a host of electrical contacts, buss bars and other electrical interconnect devices.Get the picture here : 3-minute video shows the process