Costing photo-chemical etching (eng)

Costing photo-chemical etching

The photo-chemical etching (PCE) process is characterized by the ability to produce intricate parts with tolerances as low as ± 7 microns without degrading material properties. It also produces stress- and burr-free parts with no limitations when it comes to complexity, and can be used on a broad range of metals and alloys, even difficult to process ones such as aluminium and titanium and other hardened metals.

OK, so the process can produce parts impossible to make using alternative processing technologies, but always the cost per part is crucial for manufacturing success.

PCE uses chemicals to erode areas of sheet metal to form the shape of a required part or component, so the cost of the process is made up of the cost of the sheet metal, the cost of the photo-resist, the chemicals used to erode the metal, water, power, treatment of waste, machine usage, and labour. 

Most of the labour-related overhead involved in the PCE process (which involves production of tooling, material cleaning, lamination with photo-resist, printing, developing, photo-etching, and stripping) remain constant regardless of type or size of material being processed. Etching cost is largely driven by the time it takes to process a certain linear distance of material, and by the thickness of material (thicker materials require longer processing time).  Therefore the cost benefits of PCE are further maximized by having as many parts as possible within a given surface area of material that is as thin as possible for the application.

However, it is not just the number of parts per sheet that is important when looking at the cost of using PCE. Where you would expect part cost to increase with geometric complexity with other metal fabrication processes, there is no cost increase with PCE however complex the part. In addition, the process allows the production of many different parts on a single sheet or strip/reel, which obviously has massive positive cost implications.

The process also uses digital or glass tooling which is considerably less expensive than tools used for stamping with hugely reduced lead times. Digital tooling also allows inexpensive late-stage re-iterations, which are often prohibitively expensive when using hard tooling.

Any ability to reduce manual intervention in the process obviously also reduces the cost of the process, and micrometal offers a completely automated PCE process, which slashes labour costs, and makes its per unit price especially competitive.

A PCE specialist such as micrometal can assist in cost rationalisation if engaged early in the product development process. Designing for economy in PCE means ensuring that you do not use too much metal, that you do not specify unnecessary tolerances, and that you do not specify feature sizes that are too small for the material thickness. micrometal can advise you on all of this, and will therefore ensure that you benefit from the most cost-effective fabrication technology available for precision metal parts and components.