Chemical Etching: What Is It and How Does It Work?

Chemical etching is a process that uses a corrosive agent (called an etchant) to remove unwanted material from a metal sheet, leaving behind a predetermined shape or pattern. It is a versatile and cost-effective production method that is used in various industries to produce intricate, high-quality metal parts.

Although chemical etching is increasingly popular as a method for creating many kinds of thin metal parts and components, widespread misconceptions still remain about this manufacturing process. Therefore, it may be helpful to provide an overview of chemical etching—how it works, what its benefits are, what it can do for you, and why you should hire an experienced professional company like UWE for your chemical etching needs.

The following article has been conceived with this purpose in mind, and it should help you reach a better understanding of chemical etching and how it can help you achieve your goals.

What Is Chemical Etching?

Chemical etching is a technique used to produce intricate metal components by selectively removing material from a metal sheet using chemical agents. It is therefore considered a subtractive process—that is, it involves the removal of material from a workpiece to achieve the desired design or shape, in contrast to an additive process, where material is added layer by layer to form an object (like in 3D printing).

Instead of relying on traditional mechanical processes, etching achieves its results through the interaction between chemicals and metals. This process offers several key advantages over other manufacturing methods.

One of its primary benefits is the ability to create extremely detailed and complex designs without inflicting mechanical or thermal stress on the material that might lead to deformation. For this reason, it’s particularly beneficial for applications where precision is extremely important, such as in the production of electronics, aerospace components, and medical devices.

Chemical etching’s versatility and precision make it a preferred choice for industries seeking high-quality, repeatable, and consistent results. Additionally, the method’s essentially non-mechanical nature ensures that even the most delicate designs can be produced without wear or tear on the tools.

Chemical etching is interchangeably referred to by other names, including photo etching, chemical milling, metal etching, photochemical machining, and photochemical etching. All these terms describe the same process.

How Does Chemical Etching Work?

The chemical etching process can be divided into the following steps:

1. Design – A phototool is created based on a drawing or rendering of the proposed design to guide the technicians through the production process.
2. Cleaning – The metal sheet is cleaned to remove any contaminants or oxide layers that might affect the quality of the etching.
3. Laminating – A photoresist—a specialized light-sensitive material—is applied to both sides of the metal sheet. The photoresist forms a thin and uniform layer that adheres to the metal surface.
4. Exposing – Two pieces of phototool-based film are placed on each side of the metal sheet. The sheet is then put into an exposure unit. The exposure unit emits UV light that hardens the photoresist underneath in a pattern demarcated by the film.
5. Developing – The metal sheet is sprayed with a solution that washes away the soft photoresist, revealing the exposed metal areas that will be etched.
6. Etching – The metal sheet is immersed in an etchant solution (commonly ferric chloride) that reacts with the exposed metal areas and dissolves them. The hardened photoresist acts as a barrier that prevents the unexposed metal areas from being etched.
7. Stripping – The remaining photoresist is removed from both sides of the metal sheet.

The metal part is then inspected and prepared for any further processing that may be necessary.

What Are the Benefits of Chemical Etching?

Chemical etching offers many advantages over other metal fabrication methods, such as stamping, laser cutting, and machining. Some of the more important benefits of chemical etching are:

• It can produce complex and intricate shapes and patterns with high accuracy and precision, with features as small as 0.01 mm and tolerances as tight as 0.025 mm.
• It does not cause any mechanical stress or deformation that might create burrs, sharp edges, or heat-affected zones that could affect the quality and functionality of the metal part.
• It can etch any metal or alloy that can be dissolved by an etchant solution, including stainless steel, copper, brass, nickel, titanium, and aluminum.
• It is a cost-effective and efficient method that can produce large quantities of metal parts with consistent quality and low waste.
• It is a versatile and flexible method that can accommodate a wide spectrum of designs and specifications, as it’s possible to create different depths and angles of etching simply by adjusting the etchant solution or the exposure time.

Chemical Etching: What Can It Do for You?

Applications of Chemical Etching

Chemical etching can produce high-quality metal parts for various industries and applications, such as:

• Electronics – Chemical etching can achieve high precision and conductivity for electronic components, as well as reduce their weight and size. Common electronic components fabricated via this method include circuit boards, connectors, switches, sensors, antennas, shields, filters, and heat sinks.
• Aerospace – Chemical etching can bolster the performance and durability of metal components used in aerospace applications. Common aerospace components manufactured with this process include various engine parts, turbine blades, fuel injectors, shims, washers, and brackets.
• Medical – Chemical etching can ensure sterility and a high degree of biocompatibility for these components, which helps to reduce the risk of infection or rejection. Common medical devices manufactured with this process include implants, stents, catheters, needles, surgical instruments, and diagnostic tools.
• Automotive – Chemical etching can enhance the efficiency and reliability of metal components for automotive applications, as well as minimize friction and wear. Common automotive components manufactured with this process include fuel injectors, sensors, valves, gaskets, springs, and clips.
• Jewelry – Chemical etching can produce intricate and elegant designs for metal accessories used in jewelry products. Common types of jewelry manufactured with this process include earrings, necklaces, bracelets, rings, and pendants.

These are only some of the more frequently seen applications that benefit from chemical etching. Its range of uses will likely continue to expand in the coming years.

Customization and Design Flexibility

One of the main advantages of chemical etching is that it allows you to customize and design your metal parts according to your needs and preferences. You can choose from a wide range of materials, thicknesses, and finishes that suit your application needs and your budget.

You can also create your own design or pattern for your metal parts using a software program or a drawing tool. Virtually any kind of shape or image can be used, whether it is geometric or organic, simple or complex, symmetrical or asymmetrical. It’s also possible to add text or numbers to your design if you want to include data such as identification numbers.

You typically begin the process by sending your design (generally via a .DWG or .DXF file) to a professional company that will convert it into a phototool using a laser printer or a plotter. This will be used to transfer your design onto the metal sheet using UV light. The phototool will ensure that your design is accurately reproduced on the metal part with high resolution and clarity. When necessary, it’s a simple matter to modify the phototool without significantly slowing down the production process.

Quality and Precision

Another major advantage of chemical etching is that it delivers high-quality and precise metal parts that meet your expectations and standards. Chemical etching uses a controlled and consistent process that ensures that every metal part is identical to the original design and to the other parts in the series. Because mechanical force is not involved in the process, there are no errors caused by the progressive wear and tear of tooling.

Chemical etching can produce metal parts with extremely fine features and tight tolerances. Furthermore, it produces smooth and clean edges and surfaces that do not require any further polishing or deburring (both of which tend to drive up project costs). With this process, it’s possible to create very complex and intricate shapes and patterns that would be difficult or impossible to achieve with other methods, and it can do so at a reasonable cost.

Chemical Etching: Why Should You Hire a Professional Company?

Challenges and Risks of DIY Chemical Etching

For some companies, the need for chemical etching arises only infrequently—for instance, to create a prototype for a proposed new product. This may inspire them to put together an in-house DIY operation to carry out these tasks on a strictly ad hoc basis. However, DIY chemical etching involves many challenges and risks that are not easy to master.

Some of the challenges and risks of DIY chemical etching are:

• You need to have access to the right materials and equipment, such as metal sheets, photoresists, UV light, developer solution, etchant solution, stripper solution, and protective gear. These materials and equipment are not readily available or inexpensive, and might have to be ordered from specialized suppliers.
• You need to have a suitable workspace, such as a darkroom, a fume hood, a sink, a ventilation system, and so on. Facilities of this kind are not common in most workplaces, and your company might have to rent or build a dedicated space where chemical etching can be performed.
• You need to have the proper knowledge and skills, such as how to prepare the metal sheet, how to apply the photoresist, how to expose the metal sheet, how to develop the metal sheet, how to etch the metal sheet, and how to strip the metal sheet. These steps are not simple or intuitive; they should be performed only by experts.
• You need to follow established safety precautions and regulations, such as correct handling and disposing of the chemicals. These chemicals are hazardous and corrosive, and they can cause serious harm to the health of employees and the environment if mishandled or misused.

As you can see, DIY chemical etching is not a project that can be done casually. It requires a lot of time, money, effort, and expertise.

Advantages of Hiring a Professional Etching Company

If you want to enjoy the benefits of chemical etching without the hassles and hazards of DIY chemical etching, you should consider hiring a professional company that specializes in this process. A professional company—such as UWE—can offer you many advantages that you are unlikely to obtain from your DIY chemical etching efforts.

Some of the advantages of hiring a professional company are:

• You can save time and money. A photo etching company can provide you with fast and affordable service that can meet your deadlines and budget.
• You can get high-quality and precise results. An experienced company can guarantee consistent and accurate results that can match your specifications and expectations.
• You can access a wide range of options and design possibilities. A professional company can offer you a variety of metals and alloys, thicknesses and finishes, designs and patterns that you can choose from.
• You can avoid any risks or liabilities. A professional company can handle all the aspects of chemical etching safely and responsibly, and in compliance with all the regulations and standards that apply to chemical etching.

If you decide to hire a professional company for your chemical etching needs, you should do some research and comparison before making your final choice. Not all companies are equal in terms of quality, service, reputation, and so on.

Among the most important factors involved in your decision are the experience and expertise that the company can bring to your project. How long have they been in business? Do they have experience with the specific type of product you wish to create? What certifications do they carry?

Established in 1969, UWE has both a long track record and massive storehouse of institutional knowledge relating to effective chemical etching of a vast array of metal parts and components.

What to Expect From UWE

At United Western Enterprises, our customers benefit from our unparalleled quality and expertise. We’re committed to providing them with a smooth and satisfying experience from beginning to end. We operate out of an expansive 21,000-square-foot facility located in Camarillo, California, where we perform all our specialized chemical etching processes on thin metal parts.

Our AS 9100D / ISO 9001:2015 certification stands as a testament to our commitment to industry-leading standards, developed over half a century of service to the automotive, electronics, medical, aerospace, and military sectors. Our expertise covers a diverse spectrum of applications, ranging from intricate EMI-RFI shielding to precision-engineered contact springs, as well as an array of value-added options such as laser welding and heat treating.

For more information, you can reach us by phone at (800) 964-6461 or by email at sales@uweinc.com. You can also request a free quote, and we’ll get back to you shortly.