Chemical etching is a subtractive manufacturing method that’s used to achieve precision metal parts that can be found in a wide variety of industries including aerospace and medical. The reason that chemical etching is becoming increasingly popular is thanks to its reliability for producing intricate parts without affecting the structural integrity of the metals used. So when you need a part that is exact in shape and size and without any negative affect to ductility or structure, chemical etching is the solution. In this article I’ll outline some of the advantages of using chemical etching.
The process of chemical etching is across an entire sheet of metal: a stencil in the form of a photo-resist coating is applied to the metal and then the etchant is sprayed on which dissolves the unwanted metal and leaves the part with the etchant on it. For this reason it means that unlike other etching methods that can only work on one section at a time: laser, stamping, water jet; chemical can produce results very quickly. Another advantage it has is the fact that prototyping can be done within just a few days. As the stencil is applied from a computer programme, this is easily changed and requires no tooling adjustments. So instead of taking weeks from prototype to final design; chemical etching can complete the entire process from start to finish in a few weeks depending on run time.
A lot of other metal etching processes are very high energy: laser or stamping for instance, both of which can tamper the metal’s properties as a result of the manufacturing process. With chemical etching the end product is free from any burrs or mechanical stresses which would obviously not be suitable for use in some industries. By finishing the production process without any deformation also means that the process is quicker because it requires no adjustments at the end – what you see is the part that can be used in whatever device required.
The other advantage of having a clean and smooth surface as a result of the chemical etching process is that for electronic mating components, it’s a must. As mentioned, the metal’s structure remains unchanged so any products that need low tolerances, precision and high conductivity are all perfectly suited to the chemical process. Some of these electronic components include EMI/RF shielding, electrical contacts, pins, and terminals.
Burr and Stress-Free Parts
Just by nature of the process, it creates the perfect conditions for a great number of industries. An absence of burrs means there’s also an absence of unwanted friction (and so heat too) which therefore ensures top performance for other types of radio frequency and electronic microwave components.
Being burr-free also eliminates the need for secondary deburring processes that will certainly incur cost and take time. The other benefit of the process is the ability to hold low tolerances for a whole host of different metals. Etching is a finely controlled process so we’re able to achieve the exact tolerances required by the client. Chemical etching produces exact measurements and because it doesn’t wear like stamping or use high energy like laser, it’s easy to achieve the required tolerance.
As I’ve mentioned, by the very nature of the etching process it eliminates any secondary deburring as well as the need for extended prototyping and completes the process in a shorter time frame thanks to the fact that the whole sheet metal is worked on concurrently. All of these factors translate to a more affordable manufacturing process because it’s so streamlined and efficient. And, like with water jetting, you don’t need to cut into “scrap” on the sheet metal to avoid affecting the desired part – with the photo-resist applied the scrap is removed by the etchant – it allows for there to be virtually no or very little waste product.
This is where chemical etching really comes into its own with the capability to achieve precise measurements as small as 25 μm. This means that you can rely on the final result being perfect for use and this is also repeatable. As the designs are done on computer software, it’s just a case of replicating this across large production runs if you require a great number of the metal part. There’s no extra cost for complexity, that simply doesn’t affect the chemical process. And because of this, it’s no challenge to reproduce the exact same results time and time again – no machines need re-tooling or parts fixed from wear and tear that can happen more frequently with alternative options.
For all of the above reasons, it is clear to see that the chemical etching process has a great number of advantages when compared to the other options available. As with any manufacturing process, check with the company regarding any specifications you may need, they will be more than happy to work out a solution.