Chemcut’s Blog and News


Etch Uniformity – 7 Reasons to Consider Intermittent Spray

In chemical etching, one of the growing areas of innovation that we discussed in “5 Areas to Expect Growth In Chemical Etching” was etch uniformity. Etch uniformity is becoming crucial to obtaining consistent results across larger panels. Whether the panels are for printed circuit boards or etching multiple parts, better uniformity will increase production. The difficulty in receiving an equal etch across a panel is caused by the “puddle effect” — an effect where diffusion is limited in the middle of the panel due to a higher puddle depth. This effect causes the edges to etch faster than the middle. Many companies have developed methods around the puddle effect, such as vacuum etching, but the best available solution is intermittent spray. Here are 7 reasons why intermittent spray is the best etch uniformity solution on the market.

1. Simpler Design

Our patented intermittent spray is the perfect etch uniformity solution if you are looking to improve your process but not increase the complexity of your machine. If you are limited on space on your shop floor, adding an intermittent spray won’t be an issue. It is compact and contributes a minimal addition of length to your etching system. If you already have a modular etching line but want better uniformity, an intermittent spray module can be easily added.

2. Lower Machine Costs

The simplistic design of intermittent spray also means a lower cost. Its compact design does not require many resources or much manufacturing time — thus allowing it to have a low capital cost in comparison to other etch uniformity solutions.

3. Lower Maintenance Downtime and Costs

The simple design also means easier, less expensive maintenance.

4. Faster Etching Rate

Intermittent spray provides a etch uniformity solution that does not hold back etch rates.

5. Able to Transport Thinner Products

Since this solution only consists of an additional area to spray etchant, it poses no limit to material thickness.

6. Higher Yield

Intermittent spray modules can boost yield by obtaining a uniform etch across a panel without introducing a higher risk of damaged panels.

7. Lower Operation Costs

With intermittent spray, there is no loss of etchant in the process and there are fewer utilities required to function.

If you are looking for an efficient way to improve your etch uniformity, intermittent spray is the best solution available. With it, you’ll receive a more even etch through your panels without introducing more complex and expensive systems. If you want to see how well our intermittent spray will perform on your panels, you should consider having samples etched in our in-house customer lab. Should you want to arrange a visit or request having samples etched, please contact us.

Product Showcase: 2300 Series

At Chemcut we offer three different product platforms for wet processing equipment. We offer the 2300 series, the XLi series, and the CC8000 series. Each one has its strengths, but today we will discuss the 2300 series. The 2300 series is a model that targets the quick turn and prototype markets. Here are the four unique qualities the Chemcut 2300 series equipment has to offer.

1. Small Footprint

The 2300 series’ compact design allows it to be suitable for businesses of all sizes. With this series, you can save space while getting the productivity and efficiency of a conveyorized system.

2. Reduced Sump Size

This feature requires less chemistry on-site and allows for a quick change of process chemistries. A smaller sump also means less rinse water that will need treatment after cleaning out the machine.

3. Quick and efficient installation.

This compactness of the 2300 series means easier installation and maintenance without sacrificing product performance.

4. Scalable to large production levels.

The 2300 series technical performance is easily scalable to large volume equipment like the Chemcut XLi or C8000 series.

If you are looking for a chemical etching line but need something compact, easy to maintain, and cost-efficient, you should consider our 2300 model. If you are interested in the 2300 series but have more questions, you can send your questions to us here, or you can even arrange to visit our customer lab to receive a demonstration of how it works.

6 Chemical Etching Safety Tips

If you are working in the chemical etching industry, safety should be one of your top priorities. A chemical etching shop in irresponsible hands can become a dangerous place because of the many physical and chemical hazards. In this article, we will share some useful safety tips we have learned over many years in the chemical etching industry. Utilizing these tips on top of normal safety procedures and policies will ensure your chemical etching shop becomes a safe place to work.

1. Mind the edges

After etching, any edges exposed to the etching process become sharper. Because of this, it is highly recommended to handle etched panels with gloves that will be resistant to any punctures or slashes that the edges can inflict. This is more of a concern in the field of chemical etching because parts are etched through. In the printed circuit board industry, sharp edges are produced less because there is no point where the top and bottom etching meet to form a refined knife-like edge.

2. Double-check valves

Right before you perform any task with or on your wet processing equipment, it is a good idea to double-check the valves. This will ensure there will not be an accidental release or exposure to the chemistry. It will also allow you to ensure that the necessary process controls are active.

3. Don’t leave a filling machine unattended

When you are loading an etcher with water or etchant, it may be tempting to step away and do something while you are waiting. The problem here is that it is inevitable that someone will forget and overfill the machine. When a machine overfills, the contents will begin to overflow from any openings — this becomes a hazard in the workplace because of the possibility of slipping on the wet floor and being exposed to the etcher chemistry.

4. Reduce time working inside the etcher

Image of opened etcher after water testing

Working inside the etcher can be an uncomfortable part of performing maintenance. Whether you are reaching into the etcher to troubleshoot or perform preventive maintenance, it is always best to allow the etcher to cool down to room temperature before performing tasks. If immediate access is needed, it is best then to minimize the amount of time inside the etcher and to reduce skin contact with the wetted interior. Most etchants can irritate the skin and produce toxic fumes when hot.

5. Maintain a preventive maintenance program

To prevent unexpected events of exposure, it is important to perform inspections often. Always check seals, plumbing, and containment to ensure there is no compromise. Preventive maintenance keeps your equipment in top condition and prevents any sudden, accidental releases of the contents inside any wet processing equipment.

6. Understand the active chemistry

In chemical etching, it is highly important to understand your etching chemistry. Understanding what materials or chemicals may react can go a long way in terms of safety. It is easy to underestimate what reactions can occur with your chemistry. If an incompatible component is added, the outcomes can range from a highly exothermic reaction to a release of toxic gas.

Maintaining a safe environment in the chemical etching industry is highly important. If you follow these tips you’ll be a few steps closer to having a safer chemical etching shop.

Are you looking to make your chemical etching shop safer? At Chemcut, we offer an extensive preventive maintenance agreement that is customer-specific.  This program could be annual, semi-annual, monthly, or whichever works best for you. Should you be interested in this type of service, please contact our service department by clicking here.

How to start a chemical milling shop

Chemically milled parts

Starting a chemical milling shop works very similarly to a printed circuit board (PCB) shop with a few key differences. In a PCB shop, your only goal is to etch copper so you can receive the circuit pattern you are looking for. In chemical milling, the common goal is to make multiple parts from a metal sheet. The metal used that could be, but is not limited to, copper, brass, steel, titanium, or aluminum.  Chemical milling offers an efficient alternative to photo-electroforming, stamping, wire electro-discharge machining, and laser beam machining. In this article, we will touch on where to start planning your chemical milling shop, the processes involved in chemical milling, and what equipment you will need to complete these processes.

Where to start

In chemical milling, like any other business, you should have a solid idea of what you want to produce before you dive in. One of the most important things in this industry for you to know about your product is what material it is going to be made of. Depending on the metal you want to etch, it is going to affect what equipment you are going to need. The selected metal for etching can affect what components you need in your equipment to withstand the active chemistry. Some etchants and solutions are highly incompatible with certain plastics and metals, and thus your equipment can become seriously damaged without careful evaluation. Once you have figured out what your product is, the next step is to determine what equipment you will need. In order to run a chemical milling shop, it is necessary to have equipment to complete the following steps:

  1. Prepare – Check properties and cut sheet metal to make appropriately sized panels.
  2. Clean – Remove any materials that would conflict with the adhesion of laminate.
  3. Laminate – Apply a photosensitive coating to the panels.
  4. Expose – Treat exposed photosensitive coating with light.
  5. Develop – Remove untreated photoresist from the panels.
  6. Etch – Remove exposed metal.
  7. Strip – Remove remaining photoresist.
  8. Waste Treatment – Treat contaminated rinse water to meet discharge limits.
  9. Inspect – Evaluate if products meet specifications.

Prepare (Non-Chemcut product)

To start making your sheet metal products, inspection and measurement tools will be necessary to evaluate panel dimensions and hardness. There are plenty of measurement and inspection tools available but the ones that are the most necessary are tape measures, scales, and calipers.

If you must cut out your panels from a larger sheet, it may be useful to invest in shears appropriate for the job and to pair that with a deburring tool in case it produces sharp edges.

Approximate Cost = $75,000

Clean (Chemcut product)

Mechanical cleaner

Cleaning your panels prior to lamination is important because without removing the oils and contaminants from the surface, the photoresist laminate will lift and reduce resolution. Cleaning panels for chemical milling can be done either mechanically or chemically. A mechanical set-up could range from a bucket with a scrubber to a conveyorized brush system. Similarly, a chemical clean set-up could be complete with a bucket or a conveyorized system. Selection of which one to go with can depend on the level of production you wish to achieve, and/or the tolerance for abrasions resulting on the final product. One of the functions of the mechanical clean is to roughen the surface on a microscale to obtain better adhesion of the laminate; therefore, the chemical clean option is most suitable for cases where scratches and abrasions should be minimal.

Approximate Cost = $150,000

Laminate (Non-Chemcut product)

Dry film hot roll laminator

There are two different methods to laminate your panels — wet film and dry film lamination. The most used method of applying wet film is dip-coating. This is a method where a panel is withdrawn through the meniscus of liquid photoresist. For dry film, it is typically applied with hot rollers that compress the photoresist onto the panel. Usually, thinner resist correlates with better resolution. Thinner resist layers can be achieved with liquid resists; however, they can be more difficult to apply than the dry film. With these key differences, dry film may be the most suitable for manufacturing sheet metal parts that do not require ultra-fine lines. Selection of your laminate may also depend on the material of your panel because some resists may be incompatible.

Approximate Cost = $200,000

Exposure (Non-Chemcut product)

There are two different types of exposures — flood exposure and direct imaging. Using a flood exposure consists of utilizing a photo-tool that will cover the surfaces of your panel to control which areas get treated. Direct imaging exposures do not require a photo-tool because they utilize lasers to image the design onto the panel. Regardless of the exposure type, you will have to invest in a room with yellow lighting where exposing will be performed. The purpose of the yellow room is to utilize lighting that will not harm your photoresist while it is being stored or while it is on a panel prior to developing. Depending on the desired resolution, you may also have to invest in transforming the yellow room into a clean room to reduce the likelihood of dust particles interfering with exposure. High-resolution projects require high precision, and because of that direct imaging exposures are the most efficient in cases requiring high resolution. High resolution with flood exposures can be difficult with double-sided exposures because it is easy to have misalignment between the photo-tools. Any misalignment could interfere with attempts to etch through.

Approximate Cost = $200,000

Develop – Etch – Strip (Chemcut product)

Sectional develop-etch-strip line

All three of these processes are very similar when it comes to the equipment they need. In some cases, they are capable of being performed in a bucket, but doing these steps in a bucket is far from ideal because of long wait times, inefficient use of chemistry, inconsistent results, and lack of safeguards. Objectively, the best way to go is with a conveyorized system. With conveyorized systems, the baths can be adequately controlled to maintain solution quality. These systems can also come in two different forms — sectional models and modular systems. Sectional models are chambers that are divided into sections where everything is connected. In modular systems, instead of dividing the chambers into sections, the chamber sections are constructed and then connected to others — this allows for more customizability and process flexibility. Commonly, the develop, etch, and strip processes are 3 separate machines, but if the space is available, they can all be connected into one machine so that there is only one loading station and one unloading station. The design and model are highly dependent on your production level, process needs, and available workspace.

During the developing stage, it is important to ensure that you are neither under-developing nor over-developing. Under-developing means that all the untreated photoresist is not being removed, and over-developing means the developer solution is starting to cut under the treated photoresist.  Over-developing is problematic because it can reduce resolution, and under-developing is problematic because it may need to go through the developer again — thus leading to bottlenecks. To avoid these, it is recommended to have a breakpoint, a point where untreated resist is clearly removed, at approximately 45-55% of the develop chamber length.

At the etching stage, the most critical variable is etch uniformity. To obtain etch uniformity, the surface of the panel needs a constant feed of fresh etchant. The larger the panel, the more likely it will deviate from a uniform etch. Typically, the edges etch faster than the middle. This is because effectively a puddle of reacted etchant is formed in the middle restricting fresh etchant from reaching the panel surface. Although this is a common issue with large panels, this should not discourage you from using large panels because there are engineered solutions to this problem.

While at the stripping stage of the process, it is important to have stripper solution that is compatible with your photoresist. When stripping, the goal is to remove the photoresist in small chips. If the solution is incompatible, the photoresist will be removed as large chips, goo, or very fine pieces. These become problematic in filtration and can cause the spray nozzles to become clogged.

Having all three of these processes working efficiently is the key to running a successful chemical milling shop.

Approximate Cost = $360,000

Waste Treatment (Chemcut product)

Commonly, this waste treatment is performed as a 5-step batch process. The steps consist of holding, precipitating, clearing, ion exchanging, and finalizing. Each step receives its own tank, but generally the precipitating tank and the final tank are the largest. The holding tank serves the purpose of collecting contaminated rinse water that will be sent to the precipitation tank whenever enough has been collected. The solution is then treated to precipitate heavy metals out. It is important to note that depending on your etch process, your precipitation method may vary.

Once the metals have precipitated out of solution and settled at the bottom of the tank, the water on top is decanted into the clear-well. When the water level gets closer to the precipitate, the rest of the tank contents are fed into a filtration system such as a plate and frame filter press.

When it comes to waste treatment and disposal of hazardous waste, such as the precipitate, it is also important to obtain a discharge permit and to plan a course of action so your hazardous waste can be treated. Heavy metals and other hazardous contaminants in the water are usually regulated and have limits, so it is important to receive a permit and understand what local and state regulations you must meet.

After transferring treated water from the precipitation tank to the clear-well, the water then needs to be checked to ensure the contents meet your permit limits. If the contents do not meet your limits, the water can be sent to the ion exchange tank so it can be treated with an ion exchange column. Once the limits have been met, after precipitating or ionizing, the treated water can be sent to the final tank.

Approximate Cost = $350,000

Inspect (Chemcut product)

Once your panels are completed, it is good practice to frequently check the quality. Some of the tools commonly used for quality evaluation are microscopes, calipers, pin gauges, and micrometers. These tools are all used to manually check the qualities of the final product, but there are also automated inspection tools that can be implemented into the process. The automated options can become expensive, but they offer the benefit of high production rates and consistent production quality if they are integrated with process controls.

Approximate Cost = $75,000

What is the next step?

Once you have planned out your equipment and determined your chemistry, photoresist, and materials, the next step is to reach out to the suppliers. Any additional questions you have, they should be able to clear up because there are plenty of people who enter this industry with little experience. Any supplier who is familiar with the industry should be able to guide you through every step of the way. The resources are available out there for you to learn, so why not use them to your advantage?

The total cost to become a fully equipped and functional chemical milling shop is approximately $1,700,000. Undoubtedly, going into the chemical milling industry is a big commitment, but all the upfront investment, planning, and research pays off. There are plenty of resources on the topic of chemical milling and photochemical machining so please do not feel discouraged. We are here to help. If you have any questions, feel free to contact us. If any of those questions pertain to the wet processes such as cleaning, developing, etching, and stripping, our whitepaper, “Guide to Photo Chemical Wet Processing Equipment”, goes further in depth with the equipment capabilities.

Thank you for reading! We hope you found this article useful for your journey into the industry.