Category Archive: Photochemical Etching

PROCESS BREAKDOWN: Photochemical Etching

MET Manufacturing Group (MET) specializes in photochemical etching (aka photochemical milling) by using ferric chloride acid to erode away selective areas on metal and metal alloy substrates. Utilizing customer prints and designs, MET manufactures phototooling to meet customer specifications and produce high quality photo etched products. Below is a breakdown of the photochemical etching process at MET.

Material Cutting, Preparation Processing

MET procures etching materials from a network of domestic, USA suppliers (RoHS/DFARS compliant) at the mill direct and material service center level. MET commonly processes on s 12”x19” sheet/panel size. This “common size” profile allows MET to effectively etch the features required in most chemical milling applications. It also provides the working space to effectively nest multiple pieces or designs per sheet to offer the end user the best price per piece. MET can offer various sizes for etched panels, with a minimum of 4”X4” and a maximum of 18”X30”.

Utilizing a unique coil identification number, MET is able to assign material to jobs at the routing phase to set up proper material assignments and begin the traceability process. Once the sheets are cut to size, MET processes the material through a unique cleaning process based on the material type. This cleaning process removes mill processing oils, light rust/scale, and optimally prepares the substrate for photoresist application.

Material Cutting, Preparation Processing

Photoresist Lamination

The cleaned material is then processed through a photoresist lamination process where a light sensitive, organic resist is coated to the surface of the panel. This photoresist is designed to adhere to the working panel throughout the entire etching process and acts as a mask to deflect the etching acid.

NOTE: this same process can be used after the etching application as a selective plating for detailed applications.

Photoresist Lamination

Tooling and Tooling Alignment

Every part manufactured through MET’s photochemical etching process requires phototooling. The tooling is made up of two thin mylar sheets, a top and a bottom with silver based ink printed to provide a negative of the final etched part. The silver ink provides protection from UV light during the exposure process.

MET utilizes alignment targets along the border of the tooling to ensure the top and bottom films are registered properly.


In this process step, the aligned tooling is mated with the photoresist laminated sheet. This tool to material combination is put into a machine that exposes UV light to the panel. The areas on the panel where the silver based ink is printed will block UV from the photoresist whereas the exposed, clear mylar area will be exposed away. This is the first step in transferring the product image onto the to-be-etched panel.



Development is the final etching preparation process where an alkaline solution is used to dissolve away the remaining, unwanted photoresist on the panel. Essentially the areas that are desired to be etched will fully dissolve and expose the original base material.

The development process is critical and precise. Utilizing a conveyorized developer, a skilled operator will set the conveyor speed, measure and tweak the development chemistry levels, and hold the appropriate temperature. If the operator develops the material too soon the residual lamination will not be completely removed causing the acid etching to deflect from the intended etched features. In contrast, if developed too long the imaging of the part may be distorted or the photoresist will become brittle, causing failures at fine details or edges of the etched features.



MET uses a wet etching process with Ferric Chloride as the etchant. The etchant rapidly oxidizes the substrate with the intent to fully or partially remove the surface of the base base material in the intended, engineered areas. As more metal and metal alloys are introduced into the ferric chloride etching bath the bath will lose its strength. It is a common practice to etch stainless steel and carbon based alloys on a fresh bath. As the bath ages there is a switch over point where copper, brass, and nickel alloys become nominal.

In our conveyorized Chemcut etching machines, the acid is dispersed by spray nozzles attached to an oscillating spray bar system. The acid is pressurized and sprayed onto the top and bottom of the panel as it travels down the conveyor. A highly skilled operator must be aware of the nature of the etching bath, the time and travel speed of the conveyor, and the performance of the photoresist vs the metal etching features. Most jobs require a setup sheet to be processed before final production settings are confirmed and processed.


Photoresist Removal

After etching, the operator verifies conformance of the etched product or panel to the MET print. Once approved the remaining photoresist must be removed from the panel. MET uses a stripping resist chemistry that is diluted and heat controlled for optimum resist removal. The chemistry also serves as a post etching rust inhibitor to help protect the etched metals from further oxidation. After a final rinse, the products are ready to be submitted to Quality Control for final review and certification of conformance to customer print specifications.

Photoresist Removal
Photoresist Removal

Thank you for following this MET photochemical etching process breakdown. MET is interested in helping you with your next project that could utilize our contract etching services.

Please contact us at or call 574-293-3342!

How To Choose the Right Partner for Waterjet Cutting


Waterjet cutting offers many manufacturing benefits, including extreme precision, quick turn from design to prototype or finished product, cost efficiency, and excellent cutting control. Because of the many benefits, Waterjet cutting has gained popularity in the manufacturing industry.

Suppose you’re planning to use waterjet cutting to manufacture your components. In that case, you should know the key characteristics a waterjet cutting service provider should possess.

What To Look for in Your Waterjet Cutting Service Provider

When choosing a waterjet cutting service provider, you want to partner with a company with the experience, tools, and expertise to deliver quality products that meet your expectations. Here are the things to consider to help you qualify your prospective partner:

Standards Proof and Certifications

If you want to ensure that your product will meet your custom requirements, find a waterjet cutting service provider with a registered ISO 9001:2015 quality system in place. An ISO certification demonstrates that your waterjet vendor complies to the quality standards set forth by the Industrial Organization of Standardization. This will ensure that finished products meet your quality expectations.

MET Manufacturing Group is RoHS and ISO 9001:2015 certified and offers contract manufacturing and fabrication services such as waterjet cutting.

High Capacity Machines and Facilities

The waterjet cutting service provider you select should have multiple, high-quality, and up-to-date machines capable of handling large projects. A company equipped with several calibrated waterjet machines in a well-maintained facility can accommodate more demanding orders while staying efficient and precise. It also helps ensure on-time deliverables since there’s a contingency plan in the event a machine breaks down or gets overloaded with work. One example is the OMAX 5555, an abrasive waterjet cutting machine ideal for shops that require equipment with a small form factor but can cut a wide range of medium-large sized sheet/alloy stock materials.

At MET, we are equipped with OMAX proprietary software called Intelli-MAX. A translation operating system called MAKE is used at the operator level to nest and cut products. Our capabilities also enable us to cater to different engineering file types, including DXW, DWG, AI, ORD, SVG, and STEP.

Customer Service Focus and Priority

If you’re searching for a waterjet cutting service provider, choose one that can provide you with top-notch customer service. For instance, does the company display on-time and efficient service even during the quoting phase? Doing so proves they value their client’s time, are efficient, and can manage their work effectively. Additionally, a waterjet cutting service provider should be able to provide you with a firm lead time.

MET Manufacturing Group takes pride in delivering quality products by thoroughly collaborating with our customers’ engineering departments. Through continuous improvement and customer interaction, we ensure that we surpass expectations when it comes to quality, delivery, and cost.

Quality Systems

A waterjet cutting service provider should not cut corners — choosing the fastest cutting speed to maximize profit without regard for quality often leads to a poor edge finish and parts that are potentially out of angular or surface finish tolerances. Instead, a reliable company would deliver on-time products without compromising quality. They must also have proficient quality technicians who will ensure high precision and repeatability of production. In addition, they should be capable of following your specifications accurately and providing value-added services.

At MET, we prioritize product quality maintenance. We observe a systematic workflow with customizable steps for each new job that is thoroughly laid out in our job travelers. In addition, we offer the following value-added services:

  • Black coating
  • Forming
  • Heat treating
  • Passivation
  • Plating
  • E-coating
  • Powder coating
  • Specialty packaging
  • Laser cutting
  • Milling
  • Counter sink
  • Tapping
  • Welding
  • Burnishing

Waterjet Cutting Services at MET

At MET Manufacturing Group, we provide waterjet cutting services alongside photochemical etching and other popular value-added services. Our substrate cutting capabilities include all metals and metal alloys. We also process rubbers, plastics, foams, epoxy-reinforced composites, and all types of glass except tempered glass.

MET utilizes the OMAX 5555 with a 4’7″ x 4’7″ cutting area and a 6’8″ x 5’5″ table loading size. We also have the OMAX 55100 with an 8’4″ x 4’7″ cutting area and a 10’6″ x 120”  table loading size. In addition, our OMAX waterjets support a wide variety of compatible CAD files that work with its proprietary Intelli-MAX software. These files include DXF, DWG, AI, ORD, SVG, and STEP files.

Get Exceptional-Quality Waterjet Cutting Services

Here at MET, we make it a priority to produce high-quality products that are qualified by our ISO 9001:2015 quality control procedures

Partner with MET by requesting a quote today!

Uses And Benefits Of Photochemical Etching

Click to ExpandUses-and-benefits-of-photochemical-etching

Whether working on a simple design project like a packing lid for an electronic circuit board or something with more advanced specifications and tight tolerances, photochemical etching can be a cost-effective and efficient manufacturing process. Photochemical etching gives design engineers the benefit of low-cost tooling, quick prototyping, and high precision, tight tolerance capabilities. There are several metal fabrication processes to choose from in the manufacturing industry, but photochemical etching is a reliable solution for the prototyping and production of quality thin metal components.

This blog post will help you understand photochemical etching, how it works, its applications, and why you should consider it when designing a part for manufacturability.

What Is Photochemical Etching?

Photochemical etching is a machining technique that employs photographic and chemical processes to produce parts for engineered designs in various industries. Other names for the photochemical etching process include photochemical milling, photo etching, chemical machining, acid etching, and metal etching.

How Does Photochemical Etching Work?

The photochemical etching starts with cleaning flat, sheet metal material to remove oils and contaminants. The material is then laminated on both sides using acid-resistant photopolymer film. A photo tool is applied to the laminated sheet metal and UV light is used to expose the design into the laminate, on both sides of the metal. The final pre-etching prep process is a development solution that selectively removes excess resist from unprotected areas, leaving just the part design. Using a conveyorized etcher, ferric chloride is applied to dissolve the unprotected areas leaving only the desirable part. After the etching process, the finished part is placed in a stripping solution to remove all remaining resist and applying a corrosion inhibitor to prevent rust and oxidation. Free of any contaminants, the etched parts are then ready for further processing and/or final Quality Control.

Common Metals Used in Photochemical Etching

The following metal and metal alloys are commonly used in the photochemical etching process:

  • Stainless steel alloys
  • Steel alloys
  • Brass
  • Copper
  • Beryllium copper
  • Aluminum
  • Inconel
  • Nickel silver
  • Phosphor bronze
  • Exotic alloys

What Are The Uses Of Photochemical Etching?

Etched products are commonly used in many consumer applications. Due to the versatile nature of etched parts, you can find etched components in something as small as a cell phone or as large as an aircraft.

Photochemically etched products can stand alone or be found in the following:

Electronics and Hardware

  • Fine screens
  • Sensors
  • Metal gaskets
  • Circuit components
  • Washers
  • Apertures
  • Microwave/Telecommunications
  • Cell phones
  • Hearing aids

Medical Equipment

  • Imaging equipment
  • Surgical blades
  • Medical batteries
  • Pacemakers
  • Microscope objectives


  • Telescopes
  • Radars
  • RF signal collectors

Any application that requires a thin gauge sheet metal fabrication solution should consider photochemical etching.

What Are The Benefits Of Photochemical Etching?

Low-Cost Tooling

Photochemical etching utilizes a mylar film with silver based ink as the tool to transfer the image. A general cost for an engineered tool for the photochemical etching process is approximately $400. The tooling can also be generated or revised/re-generated in 1-2 business days.

In comparison, a traditional stamping or tooling based manufacturing method could be several thousand dollars and have a significant lead time from start to first application.

Preserved Metal Properties

Unlike traditional mechanical fabricating, photochemical etching produces no jagged corners or abrasions and preserves the physical properties of the metal. This machining process does not affect the metal hardness, grain structure, or ductility because no mechanical forces are applied to the metal. Because the process does not include heating the part, there are no heat-affected zones as with other traditional fabrication methods.

Prototyping Versatility

With photochemical etching, you can make several changes to parts during the prototype development process, and the designer or manufacturer can change the dimensions utilizing the low cost tooling. A single tool can also be used to create multiple styles of a potential design.

Burr-Free Parts

The photochemical machining process has the ability to produce burr free products. Finished etched features like holes and separated edges will be smooth, rounded, and burr free.

Replicability Of Design

Photochemical etching allows patterns to be replicated several times on a panel, which enables lower costs while maintaining design accuracy.

Recessing of Material Thickness

Commonly referred to as “Half Etch”, photochemical etching allows material to be removed from only one side of the sheet. This allows for multiple depth throughout the designed part. This could be used as text identification, bend lines for post processing, recessed pocks, or general surface finishing and roughness.

Photochemical Etching Services By MET Manufacturing Group

MET Manufacturing Group specializes in thin gauge, precision sheet metal applications using photochemical etching as outlined above. MET also offers value-added services of forming, plating, heat treating, kitting, and specialty packaging for our etched products.

As an ISO 9001:2016 certified company, MET highly values our Quality Management System and the requirements of our customers. MET takes pride in dynamic customer service, competitive lead times and pricing, and building long-term relationships that continually service customer needs.

For more information about our photochemical etching capabilities, contact us at (574) 293-3342, or you can also request a quote today.