The advantages of photo etching as an efficient and accurate precision metal fabrication technology are now well known. Photo etching is a versatile and sophisticated metal machining technology, with an ability to mass manufacture complex and feature-rich metal parts and components, and is characterised by retention of material properties, burr-free and stress-free parts, and no heat-affected zones. As such it finds numerous applications from a wide range of high-tech engineering markets where cost-effective, precise, and repeatable manufacture are vital.
But there is more to photo etching than meets the eye, and one area that is little appreciated is the fact that the nature of the process can be adapted to induce a variety of different and predictable etched profile characteristics that can be used to enhance product performance and functionality, such as sharp cutting edges for medical devices or fluidic channels for component cooling.
Precision Micro has worked with numerous OEMs to utilise etched profile characteristics to optimise product design. Photo etching is extensively used in the manufacture of meshes and filters, and in one great example, Precision Micro’s extensive experience in this area was utilised on behalf of Europe’s pre-eminent shower manufacturer, where the edge profiles of the holes produced were critical to the functionality of the shower head.
For this manufacturer, a “rougher” etch was required for its application rather than a completely smooth etch, which allowed it to achieve a high-quality spray for which it had a global reputation.
For the particular showerhead in question, a simple flip action switched to one of 4 different sprays. The small spray plate was designed with 900 x 0.148 mm precision apertures with a tolerance of +/- 0.02mm. It was required that water passed through these apertures smoothly, and it was soon determined that the geometry and shape of each aperture were critical to the spray pattern achieved.
Alternative fabrication technologies – and indeed conventional photo etching – struggled to produce a high enough spray quality, so Precision Micro developed a process that produced consistent etched profiles in the apertures that generated incredibly fine and even spray patterns with little to no directional bias.
In another good example of the etched profile being used to optimise product functionality, Precision Micro worked with a medical company that required an instrument for use in ocular surgery from a high hardness material that could not be profiled precisely by conventional means.
The chosen material was medical grade stainless steel, and Precision Micro used photo etching techniques not only to profile the minute blade but also to incorporate an ultra-fine sharp edge during a single etching process. By manufacturing the product in this way, numerous blades could be produced from a single sheet of material, the need for individual sharpening was removed, and the same photo tooling was used to prepare samples and to meet volume requirements.
The list goes on. For example, Precision Micro worked with a squeegee blade manufacturer, the blade being used in surface mount screen-printing. In this application, post-process electro-polishing was used to smooth aperture sidewalls which improved paste transfer. In the manufacture of bone saws, the so-called depth edge technique is used to enhance the cutting edge.
Etching channels in fluidic devices for such applications as fuel pumps, micro pumps, micromixers, reactors, reformers, heat exchangers, and microplates also benefit from the ability to control etched profiles.
When looking at such precision applications, etching is a preferred fabricating process as it physically removes metal, whereas processes such as stamping move metal. Also, while it is possible to laser ablate such channels, they tend to be rough, and machining is extremely difficult and therefore uneconomic.
The efficacy of microfluidic devices depends on high levels of micro precision being achieved in the channels that control and enable the liquid or gas flow. Precision Micro can control plate topography, and channel geometries, even on interlaced and complex curve mixing devices, all of which optimise fluid flow.
Whatever your application, due to its size and expertise, Precision Micro is able to work with customers and devote resources to allow for the development of process adaptations such as etched channel profiles to accommodate specific applications. It also fits with the company’s ethos that it be viewed as a strategic partner in product development, not just a job shop, and engagement early in the design process will allow for design optimisation and efficient prototype or full volume production.