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Photo Etching v Chemical Etching, What’s the difference?

Photo Etching v Chemical Etching v Acid Etching, What’s the difference?

As you may or may not be aware, metal etching is known as many different terms across the world such as photo etching, chemical etching, acid etching, photo chemical machining (PCM), photochemical milling, microfabrication etching, photo chemical etching, chemical milling or photo engraving.

These differing terms are all actually the same process, and effectively all refer to the etching of metal using acids, typically either ferric chloride or ferric nitrate although some other chemicals can also be used for etching.

Qualitetch offer all these processes and services, as well as many other manufacturing methods for the manufacture of bespoke thin gauge metal components. Other processes Qualitetch offer include: EDM wire erosion, metal stamping / punching, CNC machining, laser cutting and associated services such as spot-welding, soldering, tool-making, finishing & plating, component forming & assembly work as Qualitetch offer “a total metal component solution”

The process of chemical etching is very interesting, as you basically take a raw metal flat sheet and apply a UV photosensitive resist to both surfaces, which act as a mask later in the process when the artwork profile of your required design is applied using a dedicated acetate photo-film. This process can be seen in this video link.

As you can see in the video, once the sheet is cleaned the metal sheet passes through heated rollers to apply a blue UV sensitive photoresist before it is left to cool and harden. The next stage of the process is known as the printing process, and this is the stage at which your required profile design is transferred onto an acetate photo film tool mask from your CAD drawing, to the exact measurements required for you finished metal component. We then sandwich the metal between the two sided photo tool mask and apply a UV light beam via a printing unit, which effectively hardens any unexposed UV sensitive resist not protected by the photo-tool mask, with any track lines that are protected by the mask remaining soft.

The next stage of the process in known as the developing stage, and this is the stage at which the softened track lines of the parts profile are washed away using chemistry to leave a raw metal track line of the finished component profile required. Following this process, we then load the sheet through an etching chamber of ferric chloride or ferric nitrate to etch away the raw metal track lines until the metal sheet has pierced through and leaving the finished component either loose or tabbed into the fretwork sheet, which can have cost advantages for plating and finishing.

We then need to remove the excess blue UV photosensitive film resist from the finished components to leave the parts to drawing following our QA inspection. We can then offer your metal components either flat or formed or finished and plated.

At Qualitetch we work with most metal material types including: Stainless steel, Mild steel, Carbon spring steel, Aluminium, Brass, Copper, Nickel Silver, Nickel, Phosphor bronze, Beryllium copper, Molybdenum, Silver as well as many other more uncommon materials such as nickel alloys or Nickel irons & braze foils in thicknesses from 0.0127mm to 1.60mm thick.

Let Qualitetch help you manufacture your ideas in metal and partner with a safe pair of hands within the industry for all your bespoke thin gauge metal requirement needs. If you have any enquires or questions then please feel free to call us on 01354 658787 or email or for more details online at