Photochemical etching is a high-throughput manufacturing process that produces precision metal parts with intricate patterns and tight tolerances. It uses photographic and chemical techniques to create the desired patterns. The technique is also known as photo etching, photochemical milling, and photochemical machining (PCM).

During the process, photographic techniques, such as photoresist imaging, are used to select the removable and nonremovable areas on the metal sheet. Then, an etching solution containing strong etchants is applied to the photoresist sheet to remove or corrode away the unmasked sites, creating intricate patterns on parts for medical applications.

Photochemical metal etching can be used with a range of metals and alloys, including stainless steel, titanium, brass, zinc, nickel, and copper.

Though many other methods are also available to shape metal parts, such as water jet and laser cutting, the etching or machining process is best suited to creating cost-effective and high-quality healthcare and medical components with high precision.

In this article, we will review the advantages of the photochemical process and its applications in the medical industry.

The Advantages of Photochemical Etching for Medical Devices

The photochemical etching process serves a range of applications in the aerospace, automotive, and medical industry. Here’re a few of its uses in manufacturing medical devices and implants:

Photoetching allows the simultaneous development of multiple etched parts, which makes it perfect for mass production of desired components for medical applications.
In addition to being ultra-precise, photochemical etching is a low-cost and less time-consuming etching process compared to other approaches, such as metal stamping, which require costly hard tooling.
Photoetching is a suitable process to produce medical components that are stress-free and burr free in a high volume, which is challenging with techniques like CNC machining and water jetting. Burr-free parts eliminate sharp edges that could cause tissue irritation or damage during implantation or use. Additionally, photochemical etching is a non-contact process that minimizes mechanical stress on the metal, which ensures the integrity and longevity of the component.
The photoetching technique is versatile and can be used with a range of metals, including stainless steel, titanium, copper, zinc, and tungsten, without involving expensive tooling in the process.
- After photochemical etching, the parts can be electropolished to increase corrosion resistance.

Common Applications of Etching in Medical Devices

The photochemical etching process serves a range of applications in the aerospace, automotive, and healthcare industries. Some of the common applications of etched parts in the medical industry include:

Orthopedic bone implants or other medical implants
Surgical instruments & blades
Electron guns for MRI/CT machines
Brain wave sensors
Hearing aid components
X-ray ID tags for pacemakers
Sensor elements for monitoring devices
Filters, sieves, and medical mesh
Anode and cathode grids
Stents

Photochemical Etching of Medical-Grade Metals

One of the best advantages of using photochemical etching for the development of medical components and parts is its versatility with every metal, whether it's stainless steel, titanium, or cobalt.

Stainless Steel in Medical Device Manufacturing

Among all the available elements, stainless steel is commonly used to manufacture medical devices. In addition to offering biocompatibility, the metals have many unique mechanical properties that make them suitable for healthcare or medical applications, such as:

Hardness
Wear resistance
Tensile strength
Elongation
Fracture toughness
Creep resistance

Stainless steel's durability and strength make it an excellent metal for developing components that must withstand and tolerate extreme conditions, such as high temperatures, acidic fluids, or high stress with heavy use.

The corrosion resistance property of stainless steel is contributed by its chromium content (at least 10.5% as some steel alloys contain more chromium). Upon contact with air, chromium oxide is formed, protecting the steel components' surfaces from corrosion.

Some types of stainless steel used to manufacture medical devices include martensitic steel, austenitic steel, ferritic steel, and duplex (a mixture of ferrite and austenite). Based on their grades, stainless steel Type 301, Types 302/304, Type 304L, Type 321 and 347, and Type 17-7PH are the most commonly used steel in medical applications.

Elcon Precision's stainless steel etching capabilities include:

Etching of many grades of stainless steel, including 304, 316, 420, 719, 17-4 PH, 2205, 4130, and 5510
Combining CNC machining and photochemical etching on sheets up to 2mm thick
Etching of up to 0.025″ thick sheets as large as 22×12 inches
Tolerances of ±.0005″ in many applications

Titanium Parts for Medical Implants

Did you know titanium has been used in medical equipment and implants since 1940? Yes, the impeccable characteristics of the metal, such as its biocompatibility, high strength, and high melting point, make it desirable for manufacturers to develop high-tech parts for medical, defense, and even aerospace industries.

Titanium is also corrosion resistant (due to the formation of a titanium dioxide layer when exposed to the air), non-toxic, and harmless to the human body. This property makes it ideal for developing implants and their successful integration into patients' bodies.

The pure type of titanium used in medical applications is classified into four grades, Grade 1, Grade 2, Grade 3, and Grade 4. Furthermore, 25 other titanium alloys are also available, serving a variety of industrial applications. Among them, Grade 5, Grade 7, Grade 9, Grade 11, and Grade 23 titanium have been extensively exploited to manufacture medical parts, such as surgical implants used in reconstructive surgery.

Here’s a list of medical applications that involve the use of titanium:

Cranial implants (created by titanium mesh)
Orthopedic devices and implants
Spinal implants
Bipolar plates for fuel cells or electrolyzers
Medical device implants, such as pacemakers and defibrillators
Surgical blades in autoclavable stainless steel

Elcon Precision is capable of offering the following titanium etching services:

Etching of all grades of titanium, including CP Grade 1, CP Grade 2, CP Grade 3, CP Grade 4, CP Grade 5, Grade 6A-3, and nitinol
Use of DFARS-compliant titanium where required
Etching of up to 0.040″ thick sheets ranging up to 22×12 inches
Tolerances of ±.0005″ in many applications

Let Elcon Precision Handle Your Medical Device Needs

Photochemical etching, also known as photochemical machining, is the process of creating specific geometries or patterns on a metal surface to create high-tech components and parts for medical, defense, or aerospace applications.

The process involves masking specific metal surfaces using a photoresist and removing the unmasked area by spraying an etchant to create the desired pattern. The details imprinted on the components needs to be done with precision for their efficient performance. This can only be ensured by taking the help of companies, such as Elcon Precision, experienced in performing this high-throughout process.

We’ve provided companies with the finest components and parts using our advanced photochemical machining services since 1967. In order to meet the extremely demanding requirements of our customers, we strictly control every aspect of our process.

Our in-house team of experts works with you to understand specifications and provide you with consistent finer geometries for your applications with greater precision.

What photochemical etching services do we offer?

Step etching
3D photo etching
Selective plating
Half etching

And much more!

So, if you’re looking for an industry expert to handle your etching applications, Elcon Precision is ready to exceed your expectations.

You can also email us your query at sales@elconprecision.com, and our team will assist you in resolving any issues you have.

Photochemical Etching for Medical Devices