Precise etching is to encoder disks what measurement is to engineering. Without it, these tiny disks’ inaccuracy could topple entire mechanical systems. The best encoder disks utilize some sort of advanced etching technique for optimal results. But what’s better: photochemical or laser etching?
The Best Encoder Disks Require Precision Tech
Before we get into the details of photochemical versus laser etching, we want to make one thing clear for all optoelectronic components: precision technology is a must. The old-school methods of etching on encoder disks served their purpose when that was the only available option. Today, we have new technologies that make component etchings that are accurate down to the millimeter.
If you’re stuck on the difference between photochemical and laser etching, we’re breaking down the pros and cons of each and detailing which creates the best encoder disks.
Photochemical Etching
Photochemical etching (PCE) is also referred to as photochemical machining (PCM) or photo etching. PCE is a non-traditional machining process “that uses photographic and chemical techniques to shape metal workpieces.” In other words, it creates the photo pattern as well as the part shape. And, in relation to optical components, PCE is used on metal encoder disks as an alternative to traditional laser cutting.
Pros
When looking for precise etching for optical components, PCE is a solid option. Two of the biggest pros to this technique are the lower production cost and greater part complexity. The photochemical process can handle complex component characteristics, yet the production cost is relatively low and easily replicable.
Cons
The biggest con when considering photo etching is that it’s a fairly rare and limited service. Particularly in optical components, a technique like PCE is relevant to only one of the many materials we offer.
Photo Solutions Service
Our photochemical process at Photo Solutions is very affordable, but not quite as accurate at small linewidth patterns. The result is typically around -10 percent or +20% of whatever the material thickness is. Although our process does not etch the entire material through, we are able to achieve 1,000 angstrom chrome layer and image down to five microns.
Laser Etching
Laser etching, on the other hand, uses lasers to create marks on materials by melting their surface. It’s a highly versatile process used with various materials and works by pulsing a laser beam and “releasing sudden bursts of energy at specific intervals.” The result is a marking in textual or graphical design via a slightly raised surface.
Pros
Laser etching is a common practice in our industry and applies to various encoder disk materials, not just metals. In addition to its wide application, laser etching is highly precise (especially with high tolerance machines) and effective on various material thicknesses.
Cons
Laser etching is often a more expensive process than its photochemical counterpart, mainly due to the machines’ overhead. However, after initial overhead and upkeep, this technique can become cost-effective in the long run due to repeatability and speed of output.
Photo Solutions Services
At Photo Solutions, we create photo patterns using microlithography techniques such as photoresist and silver halide film lithography. Although our PET film microlithography doesn’t etch any material, the photo sensitive silver halide film creates the image with features down to 12 microns. After we image the glass or film, we cut the part with our laser.
30-Plus Years of Manufacturing The Best Encoder Disks
The bottom line? Photochemical and laser etching are two processes that result in high quality and high tolerance optical components. When it comes to which creates the best encoder disks, it depends on your engineering needs. At Photo Solutions, we’ve invested in the highest quality machinery and educated ourselves on the techniques’ best practices. By offering these services, we’re confident we can meet our customer’s needs and exact specifications. Give us a call to go over your next project!
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