Photochemical Etch Design Engineer’s Guide

Photochemical Etch Design Engineer’s Guide

A substance having metallic properties and consisting of two or more chemical elements, at least one of which is a metal.
Copper containing specific amounts of alloying elements added to obtain the necessary mechanical and physical properties.The most common copper alloys are divided into six groups, each containing one of the following main alloying elements: Brass – the main alloying element is zinc; Phosphor bronze – the main alloying element is tin; Aluminium bronze – the main alloying element is aluminum; Silicon bronze – the main alloying element is silicon; copper-nickel and nickel-silver – the main alloying element is nickel; and dilute or high copper alloys containing small amounts of various elements such as beryllium, cadmium, chromium or iron.
Hardness is a measure of a material’s resistance to surface indentation or wear.There is no absolute standard for hardness.To quantitatively represent hardness, each type of test has its own scale, which defines hardness.The indentation hardness obtained by the static method is measured by Brinell, Rockwell, Vickers and Knoop tests.The hardness without indentation is measured by a dynamic method called the Scleroscope test.
Any manufacturing process in which metal is worked or machined to give a workpiece a new shape.Broadly, the term includes processes such as design and layout, heat treatment, material handling and inspection.
Stainless steel has high strength, heat resistance, excellent machinability and corrosion resistance.Four general categories have been developed to cover a range of mechanical and physical properties for specific applications.The four grades are: CrNiMn 200 series and CrNi 300 series austenitic type; chromium martensitic type, hardenable 400 series; chromium, non-hardenable 400 series ferritic type; Precipitation-hardenable chromium-nickel alloys with additional elements for solution treatment and age hardening.
Added to titanium carbide tools to allow high speed machining of hard metals.Also used as tool coating.See Coating Tool.
The minimum and maximum quantities allowed by the workpiece size differ from the set standard and are still acceptable.
The workpiece is held in a chuck, mounted on a panel or held between centers and rotated, while a cutting tool (usually a single point tool) is fed along its perimeter or through its end or face.In the form of straight turning (cutting along the perimeter of the workpiece); tapered turning (creating a taper); step turning (turning diameters of different sizes on the same workpiece); chamfering (bevelling an edge or shoulder); facing (cutting the end); Turning threads (usually external threads, but can also be internal threads); roughing (bulk metal removal); and finishing (light shearing at the end).On lathes, turning centers, chuck machines, automatic screw machines and similar machines.
As a precision sheet metal processing technology, photochemical etching (PCE) can achieve tight tolerances, is highly repeatable, and in many cases is the only technology that can cost-effectively manufacture precision metal parts, It requires high precision and is generally safe.key applications.
After design engineers choose PCE as their preferred metalworking process, it is important that they fully understand not only its versatility but also the specific aspects of the technology that can influence (and in many cases enhance) product design.This article analyzes what design engineers must appreciate to get the most from PCE and compares the process to other metalworking techniques.
PCE has many attributes that stimulate innovation and “extend the boundaries by including challenging product features, enhancements, sophistication and efficiency”.It is critical for design engineers to reach their full potential, and micrometal (including HP Etch and Etchform) advocates for its customers to treat them as product development partners – not just subcontract manufacturers – allowing OEMs to optimize this multiplicity early in the design phase. The potential that functional metalworking processes can offer.
Metal and Sheet Sizes: Lithography can be applied to the metal spectrum of various thicknesses, grades, tempers and sheet sizes.Each supplier can machine different thicknesses of metal with different tolerances, and when choosing a PCE partner, it’s important to ask exactly about their capabilities.
For example, when working with micrometal’s Etching Group, the process can be applied to thin metal sheets ranging from 10 microns to 2000 microns (0.010 mm to 2.00 mm), with a maximum sheet/component size of 600 mm x 800 mm.Machinable metals include steel and stainless steel, nickel and nickel alloys, copper and copper alloys, tin, silver, gold, molybdenum, aluminum.As well as difficult-to-machine metals, including highly corrosive materials such as titanium and its alloys.
Standard Etch Tolerances: Tolerances are a key consideration in any design, and PCE tolerances can vary depending on material thickness, material, and the PCE supplier’s skills and experience.
The micrometal Etching Group process can produce complex parts with tolerances as low as ±7 microns, depending on the material and its thickness, which is unique among all alternative metal fabrication techniques.Uniquely, the company uses a special liquid resist system to achieve ultra-thin (2-8 micron) photoresist layers, enabling greater precision during chemical etching.It enables Etching Group to achieve extremely small feature sizes of 25 microns, minimum apertures of 80 percent of material thickness, and repeatable single-digit micron tolerances.
As a guide, micrometal’s Etching Group can process stainless steel, nickel and copper alloys up to 400 microns in thickness with feature sizes as low as 80% of the material thickness, with tolerances of ±10% of thickness.Stainless steel, nickel and copper and other materials such as tin, aluminum, silver, gold, molybdenum and titanium thicker than 400 microns can have feature sizes as low as 120% of the material thickness with a tolerance of ±10% of the thickness.
Traditional PCE uses relatively thick dry film resist, which compromises final part accuracy and available tolerances, and can only achieve feature sizes of 100 microns and a minimum aperture of 100 to 200 percent material thickness.
In some cases, traditional metalworking techniques can achieve tighter tolerances, but there are limitations.For example, laser cutting can be accurate to 5% of the metal thickness, but its minimum feature size is limited to 0.2 mm.PCE can achieve a minimum standard feature size of 0.1mm and openings smaller than 0.050mm are possible.
Also, it must be recognized that laser cutting is a “single point” metalworking technique, which means it is generally more expensive for complex parts such as meshes, and cannot achieve the depth/engraving features required for fluid devices such as fuels using deep etching Batteries and heat exchangers are readily available.
Burr-free and stress-free machining.When it comes to the ability to replicate the precise accuracy and smallest feature size capabilities of PCE, stamping may come the closest, but the trade-off is the stress applied while metalworking and the residual burr characteristic of stamping.
Stamped parts require expensive post-processing and are not feasible in the short term due to the use of expensive steel tooling to produce the parts.Additionally, tool wear is a problem when machining hard metals, often requiring expensive and time-consuming refurbishments.PCE is specified by many designers of bending springs and designers of complex metal parts due to its burr- and stress-free properties, zero tool wear, and supply speed.
Unique features at no additional cost: Unique features can be engineered into products fabricated using lithography due to edge “tips” inherent in the process.By controlling the etched tip, a range of profiles can be introduced, allowing the manufacture of sharp cutting edges, such as those used for medical blades, or tapered openings for directing fluid flow in a filter screen.
Low cost tooling and design iterations: For OEMs in all industries looking for feature-rich, complex and precise metal parts and assemblies, PCE is now the technology of choice as it not only works well with difficult geometries, but also allows Design engineer flexibility to make adjustments to designs prior to the point of manufacture.
A major factor in achieving this is the use of digital or glass tools, which are inexpensive to produce and therefore cheap to replace even minutes before fabrication begins.Unlike stamping, the cost of digital tools does not increase with the complexity of the part, which stimulates innovation as designers focus on optimized part functionality rather than cost.
With traditional metalworking techniques, it can be said that an increase in part complexity equals an increase in cost, much of which is the product of expensive and complex tooling.Costs also rise when traditional technologies have to deal with non-standard materials, thicknesses and grades, all of which have no impact on the cost of PCE.
Since PCE does not use hard tools, deformation and stress are eliminated.In addition, the parts produced are flat, have clean surfaces and are free of burrs, as the metal is uniformly dissolved away until the desired geometry is achieved.
The Micro Metals company has designed an easy-to-use table to help design engineers review sampling options available for near-series prototypes, which can be accessed here.
Economical prototyping: With PCE, users pay per sheet rather than per part, which means that components with different geometries can be processed simultaneously with a single tool.The ability to produce multiple part types in a single production run is the key to the enormous cost savings inherent in the process.
PCE can be applied to almost any metal type, whether soft, hard or brittle.Aluminum is notoriously difficult to punch because of its softness, and difficult to laser cut because of its reflective properties.Likewise, the hardness of titanium is challenging.For example, micrometal has developed proprietary processes and etching chemistries for these two specialty materials and is one of the few etching companies in the world with titanium etching equipment.
Combine that with the fact that PCE is inherently fast, and the rationale behind the exponential growth in adoption of the technology in recent years is clear.
Design engineers are increasingly turning to PCE as they face pressure to manufacture smaller, more complex precision metal parts.
As with any process choice, designers need to understand the specific properties of the chosen manufacturing technology when looking at design properties and parameters.
The versatility of photo-etching and its unique advantages as a precision sheet metal fabrication technique make it an engine of design innovation and can truly be used to create parts that were considered impossible if alternative metal fabrication techniques were used


Post time: Feb-26-2022