6 Things Design Engineers Need to Know About Photo Etching

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The extensive development in almost all industries has led to the requirement for thin metal components with highly accurate designs. Photochemical milling emerged as a boon to fulfill these requirements. Famously called photo etching, the process has several other names, such as photochemical, chemical milling, and photochemical machining.

In simple words, it refers to printing on thin metal components. Machines and a chemical process etch the design on the sheet on which the part is produced. This process achieved quick success because of its ability to produce precise and intricate designs on the thinnest metal without harming its quality.

What is Photo Etching?

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Photochemical milling uses photoresist and chemical etchants to fabricate metal sheet components. It is so quick that a component can be produced within hours of finalizing all the necessary details.

The components produced are used in various industries, including electronic, medical, energy, and automotive industries. The level of precision that it ensures has made it more popular than other conventional manufacturing methods.

Facts Every Design Engineer Should Know About Photo Etching

Nowadays, design engineers are constantly looking for new designs to manage the ever-increasing demand for metal sheet parts. Creating a new design is not easy. It involves extensive research, choosing the right metal which will suit the part, and finding the manufacturer.

They also have to deal with budget and looming deadlines. Hoping to make your task undemanding, we have compiled a list of things you should know about this revolutionary technology if you are a design engineer.

1. Cost-effective

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Photochemical milling is one of the most cost-effective ways of designing thin metal parts. It also has the advantage of digital tooling and compound tooling, which saves a lot of money and time.

Not only this, companies experienced in this sector have an excellent lead time. If you have a complex design you need etched, other methods such as stamping or EDM will be more expensive than photo etching.

2. All Types of Designs

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Not only can the photo etching process etch simple designs, but it is also skillful at producing intricate designs with absolute precision. The machine used for the process spreads the chemical etchant onto the sheet evenly. This helps in creating a smooth surface and maintaining the quality of the product while ensuring a precise design.

3. Properties

A common problem that design engineers often face is deciding the process that does etching without affecting the quality and property of the metal. Many components now are small and thin, making them more vulnerable. Even a tiny mistake can affect the property of the metal used.

This process can maintain the metal’s properties while doing its work. Other methods often release heat, rendering the part vulnerable to micro burrs. Similarly, stamping uses force which can harm the metal sheet.

4. Useful for Large Volume

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The cost-effectiveness of the process makes it a desirable option where large volumes of parts are to be manufactured. Design tooling gives the advantage of easy modification in the design, and compound tooling is another benefit. Even during choosing the design, it is quicker than other available options.

5. Quick Process

It is also possible to manufacture multiple components simultaneously through this method. Even the lead time is less. This makes the entire process more immediate than its competitors.

6. Types of Metal

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Photochemical milling can be used on almost all metals without issues. Metals of all shapes, thicknesses, and sizes can be safely etched using this process. However, it is necessary to know the capabilities of the manufacturer you chose to work with.

Metal That Can Be Produced

Photochemical etching is a versatile method that can be used on several metals. Some of them include copper, aluminum, nickel, and stainless steel. With the ever-increasing demand for lightweight and high-performance components, this method can meet these demands because of its advanced technology. Metals such as copper and nickel alloys are also compatible with this method. Many other metals can be produced by photochemical milling.

How Does It Work?

The process of photochemical etching is straightforward.

  1. The first step of the process is digital tooling. Once the engineer has the details of the components, they can use them to determine the number of parts that can be produced on one sheet of metal. The images are transposed onto the metal.
  2. The preparation of the metal sheet is done by cutting, cleaning, and drying it.
  3. The metal sheet is covered in photoresist film and put between two photo tools. They are then exposed to UV light to harden the parts that will be etched.
  4. A developing machine washes away the parts that will be eliminated during etching.
  5. The sheet is put into an etcher, and the hardened parts are etched.
  6. The photoresist film is removed from the etched parts by putting them in a chemical solution.
  7. The components are inspected for quality.

Advantages of Photo Etching

Photo etching has several advantages that make it a better option than stamping or EDM. Some of them are:

  • Digital tooling is cheap and can be modified to meet different design requirements without taking much time. This makes the process of selection quicker and easier.
  • The process is perfect for components that have a low tolerance.
  • Unlike other alternatives, photo etching uses chemical reactions to eliminate all the unwanted parts and the components remain free of any deformation.
  • Another advantage is that it does not alter the properties of the metal. This is because no heat or hard force is used during the process.
  • The production time required is lesser than any other method, making it an ideal option for manufacturing large quantities.
  • Chemical milling can even etch the most intricate design with high precision. Since they are made at the same time, the process also saves time.


Photo etching is a simple and quick way of manufacturing intricate designs on thin metal sheets. It is versatile, cost-effective, and efficient. With all of these advantages, it is an obvious and perfect alternative to conventional methods.