Conard's Photo Etching Blog

How Photo Etching and Electroforming Apply to Metal Filtration

Posted by Kathleen Stillman on Jun 23, 2015 1:24:43 PM
Kathleen Stillman
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Metal filtration media are produced in a number of ways: mechanical perforation (stamping or punching), woven wire, and sintered metal are the most common forms of fabrication.    Metal filters can be as prosaic as a kitchen colander or as esoteric as optical meshes filtering the far infrared and submillimeter electromagnetic spectrum. Precision metal screens are used to size particles for pharmaceuticals, pigments, and other powdered or granular products.


Photo etching is a very efficient and cost effective way to make lots of holes in metal because they happen all at once.  Designing an etched screen has two important rules:  the minimum holes size must be at least 110% of the metal thickness, and the minimum center-to-center distance is metal thickness plus hole diameter.  The smallest hole that can be etched using conventional methods is .004" (100 microns) on .002" metal.

Electroforming has different rules because the process adds material, typically nickel, rather than removes it.  Using microlithography techniques, it is possible to produce pores as small as 5 microns (.0002".) And, the distance between holes can be barely 25 microns.

Etching and e-forming open up new realms of small-hole possibilities.

Other important benefits of using etching or e-forming for metal filtration and screens:

  • holes are completely burr-free
  • holes can be nearly any shape
  • different sized and shaped holes on the same part-at no extra cost

Both etching and electroforming can produce asymmetrical holes.  Ratio etching produces conical holes that are smaller on one side than the other.  Layered electroforming is used to produce holes of distinctly different sizes, and often thicknesses, on each side of a part.

Etched screen panels up to 24" x 60" can be seam welded to create continous screens of nearly any length. Our plating tank can accommodate up to about 12" x 18" screens.

The myriad applications we've seen for metal screens and filters include:

  • speaker grills
  • smoke detectors
  • microphones
  • hydraulic fluid
  • spectrometers
  • photonics
  • fuel cells
  • batteries
  • fruit juice
  • pressure drop
  • fuel valves
  • brewing
  • fluid controls
  • gas analyzers
  • particle sizers
  • nebulizers
  • atomizers
  • lighting diffusers
  • deposition masks
  • toner dispersion
  • inkjet nozzles
  • EMP grids
  • and the list goes on.

In addition to enabling tremendous flexibility in the design and dispersion of filtration holes, both photochemical manufacturing processes can create the profile of the finished part, no matter how irregular, at the same time--without any additional steps.

Metal filtration elements are used in many industrial, scientific, medical, electronic and aerospace products.  They are use in the management, control, analysis, and flow of solids, liquids, gasses and even photons!

If you are ready to see whether a photochemical manufacturing process can help you with a filtering challenge:

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Topics: Metal Filtration