Photo etching is a widely known technique for producing precise and detailed metal parts with minimal product waste. It uses light-sensitive material, photolithography, and etching chemicals to etch metal into complex patterns. This process is also commonly used in various industries, including the electronics, aerospace, medical, automotive, and defense sectors.
Since 1977, PCM Products has set the standard for excellence in photo chemical machining, chemical milling, and chemical etching. We have continually invested in state-of-the-art equipment and trained our expert technicians to deliver unmatched precision and quality to our clients. Moreover, we offer comprehensive services, including designing, prototyping, and producing various parts.
What Is Photo Etching?
Also called chemical or photochemical etching, photo etching is a versatile process that uses photoresists and chemicals to remove selected portions of a metal sheet. This creates intricate and precise parts that can be used in multiple industrial applications. The process suits various materials, including copper, brass, nickel, and stainless steel.
One of the significant benefits of chemical etching is its ability to produce high-quality parts with tight tolerances and minimal material waste. Unlike traditional metalworking techniques — such as stamping and punching — chemical etching does not require costly tooling or molds. This makes it an ideal process for small production runs and prototyping.
The technique offers design flexibility, allowing designers to create complex patterns that would be challenging or impossible to achieve with other methods. It can also produce parts with intricate patterns, text, and graphics, ideal for applications like nameplates, signs, and other decorative elements.
The Etching Process
From designing to finishing, chemical etching involves a series of intricate steps. Let’s take a closer look at the step-by-step procedure:
Step 1: Design Creation
In chemical etching, designs are created and developed using specialized software and applications like Adobe Illustrator, AutoCAD, and SolidWorks. Customers will then provide a concept draft to the experts, who will convert it into a workable file. From there, technicians will review the design and make adjustments to ensure optimal results.
Step 2: Material Selection and Preparation
While almost all metals can be etched, not all materials are suitable for every project. Commonly used materials in chemical etching include copper, stainless steel, and aluminum. Once the metal is selected, it is cut into sheets and cleaned thoroughly to eliminate grease, oil, or oxidation traces.
Step 3: Photoresist Coating Application
A specialized coating machine is used to apply the photoresist material onto the metal sheet. This coating enables precise etching of the metal that needs to be removed while protecting the part used in the final component.
Step 4: UV Light Exposure and Development
The sheet is placed between two films inside an exposure unit. Both sides of the sheet are exposed to UV light, causing the photoresist material to polymerize and harden wherever the light touches it. During development, the soft or unexposed photoresist is washed away, leaving only the hard photoresist. This will protect certain areas of the sheet from the etchant, enabling the desired parts to be formed.
Step 5: Chemical Etching Procedure
The chemical etching process involves spraying various etchants onto the developed metal sheet. Moreover, using the appropriate chemicals is crucial in achieving an efficient and effective fabrication process for metal etching. Common etchants include ferric chloride, ferric nitrate, and sodium hydroxide.
Step 6: Photoresist Stripping and Final Inspection
The remaining photoresist is removed from the sheet, resulting in the final components specified by the customer in their submitted files. The parts are then meticulously inspected to ensure they meet the required dimensional specifications, checking every detail for imperfections or defects. Additionally, this stage determines whether any value-added services are necessary.
Chemical Etching Applications
Chemical etching is widely used in various industries due to its ability to produce complex and precise metal parts with exceptional accuracy. Some of the most common applications include the following:
The aerospace industry demands materials of the highest quality that can withstand extremely high temperatures. Chemical etching provides a solution for dissolving metal without heat, reducing unwanted edges, burrs, and structural alterations. Photo-etched components commonly used in aircraft manufacturing include lead frames, EMI/RFI shielding, radar units, and telescopes.
Chemical etching is utilized in the electronics industry to produce complex circuit boards, electrical contacts, and other electronic components. This process enables the creation of precise geometries, making it an ideal technique for fabricating high-performance electronic devices.
Common automotive parts produced through etching include gears, brake components, fuel system parts, engine components, and connectors. The use of etching in the automotive industry has also contributed to cost savings, reduced waste, and faster production times.
Here are additional metal parts that can be achieved through etching:
- Perforated metals
- Metal spacers
- Flat springs
Types of Finishing for Photo Etching
Photo-etched parts require finishing to protect them from corrosion and wear and to enhance their appearance. There are several types of finishing available, including the following:
- Anodizing: This applies a protective oxide layer onto the part’s surface. The coating can then be colored, making it an attractive finish option.
- Plating: This involves applying a thin metal layer onto the part’s surface. Common plating materials include gold, silver, copper, nickel, and chrome.
- Painting: This provides an attractive finish and can be customized with various colors. It also offers protection against corrosion and wear.
- Powder Coating: This is where a dry powder is electrostatically applied to the surface. The part is then heated, causing the powder to melt and form a durable coating.
- Silk Screening: This printing process is where ink is pressed onto the surface through a fine mesh screen.
Key Considerations When Selecting a Photo Etching Partner
It is important to look for the best service provider to ensure that the project is completed with the highest level of quality. The following are some of the essential factors to consider when finding the right partner:
Expertise and Experience
Looking for a company with a strong track record of completing successful projects and producing high-quality products is essential. They must also have experience and expertise to produce precise results that meet the desired requirements. Lastly, they must thoroughly understand the photochemical etching process and be up-to-date with the latest techniques and technologies.
Equipment and Capabilities
The importance of modern equipment and technology in the chemical etching process cannot be overstated. Advanced tools and machinery allow for precise and accurate etching, producing high-quality products. Therefore, choose a partner equipped with cutting-edge technology and equipment. They must also be able to handle the production needs, whether it is a small run or a large-scale project.
The smallest errors can result in significant issues, making it imperative to find a partner who prioritizes accuracy and precision. One way to ensure this is by partnering with a company that utilizes the latest technology and has a robust quality control system. It is also important to consider their team of professionals and their level of commitment to quality evaluation and inspection.
Ongoing technical support can help you stay up-to-date with the latest advancements in photo etching. A partner who invests in research and development and stays current with the latest trends can offer valuable insights into new techniques and methods. Moreover, the training and support provided by a partner can help optimize the processes and get the most out of the investment.
For instance, they can guide how to best design the components. They can also help troubleshoot issues during the process and offer advice on improving production methods.
Partner With PCM Products for Your Photo Etching Needs
At PCM Products, our in-house capabilities are second to none! This allows us to provide customers with faster lead times, competitive pricing, and superior quality control. We also understand that secondary requirements are critical to achieving the final product. That is why we offer value-added services as part of our commitment to delivering turnkey solutions that exceed expectations.