Q1. What is chemical etching process?
Chemical etching is a sheet metal machining process that is used to manufacture complex components with high levels of accuracy. The process works by printing the component design onto a photoresist mask which is laminated onto the metal. The areas of photoresist which have not been printed are developed, exposing the metal, which is subsequently etched away.
Q2. What metals can be etched?
Etching can be applied to almost any metal type. Typical materials include steel and stainless steels, nickel and nickel alloys, copper and copper alloys, aluminium and hard to machine metals, including highly corrosive-resistant metals such as titanium and its alloys.
Q3. What chemical is used in etching
Most metals are etched using ferric chloride, a safe to use, recyclable etchant which can be regenerated and reused, though other proprietary etchants are used for specialist metals and alloys.
Q4. What sheet sizes and thicknesses can be etched?
Sheet metals between 0.010mm and 1.5 mm thick can be etched. The thicker the sheet the longer it takes to etch meaning metals above 1.5mm are uneconomical to process.
Precision Micro is unique in its ability to process very large sheets up to 600 mm by 1500 mm, but standard sheets processed are 305mm x 550mm in size.
Q5. How accurate is chemical etching?
Standard minimum etching tolerances are ±10% of the metal thickness being etched, to a minimum of ±0.025 mm.
With development, greater accuracy can be achieved so it is encouraged that customers partner with Precision Micro early in the design phase so an appropriate etching method can be developed.
Q6. What are the benefits of chemical etching?
Chemical etching does not use mechanical force, unlike stamping which subjects sheets metals to extreme pressures – often over 100 tonnes with modern machines. This causes changes in the material grain structure and burrs are common around the edges of the metal. Often, these burrs need to be removed with costly and time-consuming post-process operations.
Etched parts are burr- and stress-free, flat and leave the material properties unaffected.
Chemical etching can also produce very accurate engraved features at the same time the material is being profiled, such as fluidic channels, logos or part numbers. These features come at no additional cost.
Q7: What level of detail can chemical etching achieve?
The minimum standard etched opening achievable is 0.1 mm, but with development etching can achieve even finer features.
Q8. How much does chemical etching cost?
Chemical etching uses digital tooling which is inexpensive, very easy to adapt and does not wear out, unlike presswork tooling.
Material thickness and component size are key cost drivers as you pay by the sheet, not by the part – the more parts per sheet, the lower the unit price. Thicker sheets take longer to etch and this is reflected in the cost of the component.
Q9. What are the minimum/maximum quantities chemical etching can produce?
As one of the largest sheet metal etching companies in the world, Precision Micro supplies its customers with component quantities measured in the millions.
Low-cost digital tooling ensures prototype quantities can be supplied quickly and economically.
Q10. How long does chemical etching take?
Chemical etching lead-times are measured in days, not weeks or months like traditional metal machining technologies.
Subject to quantities required and capacity, standard components which require no additional post-processing can be supplied in less than two working weeks. Urgent demands can be supplied even quicker.