Photochemical Machining

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  • A form of Industrial Etching
  • It applies processes similar to Photolithography but for Sheet Metal Fabrication
  • Due to the gentle nature of the process it can even work with Foil
  • The main applications are:
    • Mesh
    • Features such as Grates etc, which are too small and/or too closely placed to be produced by other methods such as Waterjet Cutting or Laser Cutting
    • Although suboptimal compared to Stamping at larger scales, PCM can be of use for Complex yet Thin Metal Parts Such As:
      • Fuel Filters for Cubesats
      • Potentiometer "Wipers", Battery Connectors
      • Small Trays/Doors for Portable Electronics (Sim Card Slot Holder, Battery+Data Card Door on Cameras, etc)
      • Grills for Speakers/Microphones
      • Flat Springs and Flexure Mechanisms
  • Also seems to be used in Scale Modelmaking

Basic Process

Existing Open Source Designs

Applied Science (YouTube Channel)

  • A Video by the YouTube Channel "Applied Science" Titled "How to make precise sheet metal parts (photochemical machining)"
  • Utilized a Dry Photoresist Fil
  • This was run over the cleaned metal sheets via a Laminator As Shown at 8:19 in the Video
  • Given the Film is Multilayered, an thus "Uptake" Spool was needed for each side to peel off the protective layer
  • A Photomask was then applied
  • It was then Exposed via a Device Consisting of:
  • The Sheet was then Developed
  • The Sheet was then Rinsed
    • They mentioned a Rinse Tank was used, unsure if this was a device similar to the developer machine/the etching machine, or if it was merely a tub filled with water
  • THe Sheet was then Etched
    • As shown at around 17:16 in the Video they made a device for this step
      • It consists of a holder for the mesh bag the sheet is in
        • The Holder is a Square Plastic Frame with Clips to Hold the Bag on the Inside of the Frame (It also is mentioned a handle could be added to the top to allow moving from device to device)
        • It has rollers, making it akin to the frame of a small cart
        • Via a magnet holding module attached to the square frame (in this case perpendicular to the overall frame) ,the Bag Holder and an external OpenBuilds cnc axis are magnetically coupled. This allows the bag to be moved in a reciprocating motion in and out of the spray nozzles, without the motors and other components being exposed to the Etchant
    • There are two Spray Nozzle Bars used to Speed up the Etching Time Drastically
  • Finally the Photoresist is Removed
    • At 20:41 this process is mentioned
      • They used a Sodium Hydroxide Solution
      • Mentions that (at least with this Photoresist) it doesn't dissolve but rather "comes off in chunks"
      • They mention a "Flow Cell" where the solution would be flowed over the part, transporting any chunks with it out of the top of the bag (to aid in the automation of the overall process)
        • Didn't mention how successful it was, but either way mentioned that it has been disassembled pre-documentation and that the rest of the video will just leave the photoresist on

Partial BOM

Industry Standards


  • Only really relevant for small scale, but it seems the company Micro Mark sells a kit to fill this niche

Micro-Mark Pro-Etch Photo Etch System


  • Seems most systems still require some manual inspection in between steps, and manual part removal

My Metal Business Card

Don's Metal

Internal Links

External Links