get the most out of chemical etching for your precision part.


Chemical etching is a precise manufacturing process used to create intricate parts with high accuracy. When designing chemically etched precision parts, several key considerations must be taken into account to ensure optimal results.

avoid unnecessary complication

Dimensional tolerances play a significant role in the success of chemically etched precision parts. Tolerance your spec around the functionality of the part – don’t overcomplicate!

Often, a design requirement drives the need for manufacture in the first place but it is essential that the designs are carefully specified to be compatible with the chemical etching process. Our experienced engineers can work with you to make any necessary adjustments for optimum results.

metal thickness

Metal thickness in relation to sheet size and tolerances must be taken into account. The ultimate function of the part has to be considered, particularly if it is intended to perform a structural role. This will affect costs and tolerances: the tighter the tolerance band, the smaller the sheet size, and the higher the costs. Effectively, economies of chemical etching are best realised by being generous with tolerances. As a rule of thumb, we recommend +/- 10% – 15% of material thickness with a minimum tolerance of +/- but our skilled NPI engineers can work with you to achieve your requirements.

Additionally, metal thickness affects minimum feature sizes: the minimum dimension for etching holes is at least 110% of metal thickness. Because the process uses etching solution to dissolve the metal to be removed, in order to etch all the way through the metal, there needs to be enough space for the etchant to flow. The area between holes needs to be at least equal to the metal thickness. This is referred to as the undercut.

 

material selection

Material selection is crucial to achieve the desired properties and performance of the final part as different metals have different properties. While chemical etching is agnostic when it comes to a metal being strong, hard, soft or brittle, the resulting part’s performance may be affected.

bend lines and ratios

When you’re working at a micro-scale, it is especially important to make sure bend lines are compensated for in the original design. Similarly, etch ratios need to be considered – particularly when you need to balance strength (thicker part) and design resolution.

It is important to take into account inside and outside ratios. The chemical etching process does not cater to 90° angles which means certain features cannot be achieved. Where certain elements are essential, we can combine chemical etching with electroforming, laser welding or other precision manufacturing methods to achieve the desired result.

tagging

Where appropriate, Tecan can use small tags (also known as tabs or tie-ins) to hold multiple components in a larger sheet of metal. This enables us to efficiently produce large numbers of precision parts with tight tolerances in a single process. We offer a number of tagging options dependent on component size and shape, how it will be used and how thick it needs to be. From there, we can assess which variant is most appropriate for your requirements.

surface finish

Moreover, surface finish requirements should be clearly defined to meet the desired quality standards.

conclusion

By addressing these considerations during the design phase, manufacturers can produce high-quality precision parts that meet the required specifications and performance criteria.

 

Designing chemically etched precision parts requires careful attention to detail and thorough consideration of various factors. Material selection, dimensional tolerances, and surface finish requirements are essential aspects that must be carefully planned to achieve optimal results. By following these design considerations, we can help you create intricate parts with high precision and accuracy, meeting the demands of modern industries.