When it comes to electronics manufacturing, precision is everything. When your products are being built and tested in mass quantities, you need to have a clear vision while approaching the design process.
Product stencils are crucial in the electronics manufacturing process because they enable workers with precision tools to sell components onto printed circuit boards (PCBs) with accuracy and efficiency. However, as production lines continue to increase in complexity, manufacturers must re-evaluate how they approach their stencil manufacturing needs.
Most of the manufacturing sector has come to embrace “Total Productive Maintenance” (TPM) to increase productivity and cut costs. With TPM, Rayming PCB & Assembly achieve high production levels through “on-demand” or “just-in-time” manufacturing by taking a far more preventive approach toward their industries.
“TPM” is a process that uses computerized tools to eliminate waste, improve productivity and reduce costs by enabling manufacturers to prevent issues before they occur. In addition, it is a way to increase efficiency by reducing downtime and reducing cycle times through preventive maintenance.
Stencil Technology Evolution and History
The stencil manufacturing industry originated in the mid-20th century when PCBs replaced vacuum tubes in electronics. The new technology required new materials and design skills and led to PCBs and production equipment development.
Manufacturers developed the first stencils with perforated metal or screen mesh used for manual photo-etching. As technology advanced and production demands grew, stencils evolved into aluminum or Kynar® (polyvinylidene fluoride) sheets that would be helpful for laser cutting. Compared to screen mesh stencils, laser-cut stencils are more resistant to wear and tear, require less maintenance, and are considerably cheaper.
Today, PCB manufacturers are using laser-cut stencils for both inventories build and run production of a wide variety of PCBs. These include wire bondings, surface mount boards (SMT), printed circuit boards (PCB), and custom sizes. In addition, there are a large variety of materials that we can produce with laser-cut stencils. These include Kynar®, FR4, and other flexible materials. Laser-cut stencils can also be helpful for both manual and automated manufacturing methods.
Electronics stencils are helpful in various industries, including the fiber optics, lighting, aerospace, and defense industries. In addition, we find them in military applications and sports, automotive, and transportation products. Stencils are also helpful in fields as diverse as security systems, medical equipment, and GPS installation.
Stencil Manufacturing Technologies
When designing and fabricating SMT stencils, the options are relatively limited.
It is essential to know the different technologies available before comparing the two. In addition, choosing the manufacturing method depends on many factors, including the budget, lead time, and what the end-user is looking for.
Electronic stencils implement electronic components onto printed circuit boards (PCBs). The electronics industry is now pushing the envelope of stencil technology more than ever.
Despite advances in printing techniques such as inkjet printing, laser cutting, and additive fabrication, it is still important to consider how much a company can afford to use modern manufacturing technologies.
1. Electroforming process
The process of electrophoretic deposition (EPD) is a low-temperature, non-damaging method for producing stencils. The process involves immersing a multi-layer photoresist stencil onto a negative electroform. Afterward, the stencil is removed from the electroform and washed, removing excess photoresist material and other debris. This is an additive process that requires using a stencil and electrophoretic deposition (ED) material.
Why use EPD?
Electrophoretic deposition (EPD) is the most cost-effective solution for creating digital stencils. The process is economical, as it does not require much material, and we can accomplish it quickly. In addition, it is a high-volume manufacturing process that we can do in-plant, which eliminates the need for high-capacity equipment.
Most of the companies that have switched over to EPD have found that it has improved productivity by reducing shop floor turnaround times and making production lines more efficient.
2. Chemical etching process
Chemical etching is a form of subtractive manufacturing that uses chemical treatment to remove material from substrates. The process is commonly used for PCB manufacture and is commonly used to create stencils.
The process includes etching the stencil onto a PCB, cleaning the stencil and board, then repeating this until a product is successful.
Etching is one of the most time-consuming processes behind manufacturing specifically designed electronic boards, sub-assemblies, and circuit boards. The technique and process required are long and tedious, so some manufacturers are now turning to laser-cut stencils.
Why use etching?
Most companies use chemical etching because of its cost-effectiveness. It enables manufacturers to produce a large amount of stencils in a short amount of time while also creating complicated patterns. In addition, etching is known as a reliable technique because it has been around for decades.
Chemical etching is still the preferred method for creating stencils in many companies. This is because using a chemical process enables manufacturers to create very fine details into a stencil.
Process
a) Film Stripping: Film stripping is a process in which we spray an etching solution that contains acid onto a panel. The film sticks to the copper and then peels off by further etching.
b) Etching: It starts in a bath of a chemical solution. It etches the exposed copper, which removes a thin layer of copper. As it etches, the film dissolves into the solution. The inner layer becomes a part of the film, which strips it off.
c) Tin Stripping: Tin stripping is one of the most popular methods because it offers an inexpensive solution to stencil manufacturing. The process involves removing the product in a bath of strong acids, which etches the copper. The acid then neutralizes into the bath, leaving a thin layer of tin behind.
d) Control: Etch control is one of the most popular methods used by manufacturers to eliminate product defects. It involves placing the stencil in a furnace and then spraying it in a chemical solution which does not allow the etching process to occur. Over time, the stencil begins to peel off due to pinholes and other defects.
e) Automatic Optical Inspection: AOI is a quality assurance method that monitors the etching process. AOI is useful in determining etch rates. In addition, it allows manufacturers to identify the appropriate time to apply the control procedure.
3. Laser cutting stencils
Laser-cut stencils are also known as digital stencils, and it is a form of subtractive manufacturing that uses computer-controlled lasers to cut materials into specific shapes and patterns.
The technique and process are relatively new in the world of product manufacturing. It came into existence in the manufacturing sector between 2010 and 2012, a fairly new technology.
Although this process is still in its infancy, manufacturers can realize benefits such as reducing the time and material needed to create stencils. In addition, laser-cut stencils are more accurate than chemical etching stencils.
Why use laser-cut stencils?
Companies that have started to use laser-cut stencils as a means of manufacturing have found many benefits. The process is fast, accurate, and precise, enabling manufacturers to create products in higher volumes and with excellent quality.
Many companies are starting to switch from chemical etching to laser cutting because it is a more cost-effective solution for manufacturing. In addition, laser cutting eliminates the need for large amounts of chemicals, and there is no need for an extra process of washing afterward.
The laser-cut stencils have proved to be a more cost-effective solution for manufacturing. In addition, it is excellent in time and material for creating stencils.
Process
a) Laser machine setup: Setup is preparing the equipment that a laser machine requires. This includes cleaning and calibrating the machine settings.
b) Hole cutting: A large aperture laser machine helps cut the stencil. It loads the stencil material into a drawer, where it then moves upward into the machine’s cutting zone. The machine’s aperture then cuts a hole or pattern in the material.
c) Hole checking: After cutting the pattern, a scanning laser beam is helpful to inspect the cavity. It fixes any imperfections, and then the stencil moves back up into the machine.
d) Deburring and polish: The laser machine uses a water jet to remove the burrs underneath the stencil. The edges are then polished using a buffing wheel to reduce scratches and defects in the finished product.
e) Framing process: The laser machine cuts the stencil into the desired mold form. The stencil then moves into the forming area. After this, it stacks and groups the mold forms in a given order.
f) Final QC: The final quality control process is known as the inspection of the finished products, and it involves checking for defects. This process also includes double-checking and inspecting the product for any imperfections.
g) Product packing: We then remove the stencil from the machine, and it moves again into a cleanroom for packaging. We then place it into a box containing an inert material that prevents metallic flakes from naturally rusting and spoiling the product.
Comparison Between Laser Cut Stencils and Chemical Etching Stencils
As PCB manufacturing has progressed, demand for stencil manufacturing has increased. At the same time, a variety of new technologies have come to market. Laser-cut stencils offer many advantages over chemical etching in terms of speed and cost, but what exactly makes them so much more efficient?
1. Cost
This industry is very competitive and has a cost-conscious environment. As a result, both manufacturers and end-users are looking for effective methods to cut costs in the production process. Laser-cut stencils offer most of the same benefits of chemical etching but without all the drawbacks. Stencils are much less expensive than etching – this is achieved mostly by using less material and reducing waste. Additionally, manufacturing processes with laser-cut stencils are often much more efficient than those that use chemical etching.
2. Speed
Because laser-cut stencils can be automated, manufacturers can increase productivity without impacting quality. In many cases, this means that PCB manufacturers can reduce the time required for their manufacturing processes. This usually results in a significant increase in productivity.
3. Precision
The most significant advantages of laser-cut stencils are their precision and durability. In POS applications, these capabilities ensure high-quality components at a lower cost than chemical etching. The benefits of laser-cut stencils are evident when comparing prototyping and production, especially when you factor in the number of times you produce an item.
In the prototyping process, manufacturers need a great deal of precision for quality assurance. Laser-cut stencils are far better at producing consistent quality than etching, making them ideal for prototyping. However, once an item has been tested and approved, the precision required is less stringent. As a result, mechanical wear can lead to lower quality lines in etching stencils, whereas laser-cut stencils will not lose their accuracy under these conditions.
4. Ease of use
Stencils are also much easier to use than etching. Here again, the benefits of laser-cut stencils become evident as soon as you consider prototyping and production. In prototyping, developers will want a laser-cut stencil that is easy to work with, reducing their chances of screw-ups or mistakes. In production lines, you want an accurate and reliable product, making laser-cut stencils an ideal choice.
5. Quality
Another significant benefit of laser-cut stencils is their ability to produce better quality that is resistant to wear. Whereas etching stencils need to be replaced or reworked after a certain number of iterations, laser-cut stencils can withstand 100,000 or more pressings with no problem.
6. Automation
Laser-cut stencils are ideal for automation because they offer flexibility and ease of use. These qualities mesh well with automation because they rely on repeatability and predictability. Automation requires materials that we can use without modification, and you want something easy to use because it keeps down costs.
7. Static prevention
Another benefit of laser-cut stencils is the ability to protect against static build-up. Static build-up can reduce ink droplet penetration, which can decrease image quality. One way laser-cut stencils keep this from happening is with a thin layer of non-corrosive material on their surface that prevents ink from sticking to it.
8. Protection from wear and tear
One advantage of chemical etching is that etch tanks need to be replaced or cleaned out occasionally for optimum performance. These tanks often need cleaning because they will eventually corrode and ineffective. Also, etching stencils are subject to wear and tear, meaning that the stencils need regular replacement. All components can deliver their functionality in laser-cut stencils longer without frequent replacement.
9. Safety
Laser-cut stencils offer the highest level of safety in comparison with etching stencils. Since laser-cut stencils consist of acrylic and other non-corrosive materials, it is highly unlikely to lead to dangerous situations or conditions. They are also easy to handle and operate, increasing safety during manufacturing.
10. Maintenance
Laser-cut stencils are also much easier to maintain. Laser-cut stencils are easy to clean and keep clean, maintaining them with minimal work. On the other hand, etching stencils will surely require a higher level of cleaning and general upkeep, which can add to costs.
The Future of PCB Manufacturing
The evolution of PCB manufacturing over the next decade will likely put an even greater emphasis on cost reduction, speed increase, and quality improvement. As a result, manufacturers will likely continue to rely on laser-cut stencils for greater efficiency and lower costs. Another factor driving the adoption of these stencils is their ability to be easily adapted to automation. As the industry continues its transition towards automation, laser-cut stencils will offer an even greater advantage over-etching based on their efficiency and low maintenance.
In the PCB industry, several design houses are using laser-cut stencils to create highly detailed stencils with a very small amount of material. The stencils have a design so that CNC laser machines can easily and efficiently cut them. Further, the high quality of the laser cut stencils allows them to be helpful during many stages in the PCB production process. Though they will continue to operate, etching stencils will likely become even more popular in the future.
New Developments in Stencil Material Technology
In recent years, developments in inkjet printing technology have enabled the development of new stencil materials that will make even more efficient laser-cut stencils. In addition, these new materials have improved material flexibility and rigidity, which makes them easier to use in spray painting and electroplating.
Inkjet printing also has significant benefits for the environment compared with traditional etching. With inkjet printing, stencils consist of recycled materials and small materials. Also, the process produces clean stencils that do not contain toxic chemicals or harmful pollutants.
As the PCB industry continues its push towards automation, better stencil materials will play a central role in achieving this goal. In addition, the need for more efficient and cost-effective products will continue to drive innovation in this industry. The integration of new stencil materials will play an essential role in this process, as they can create more efficient laser cutting machines that can produce high-quality stencils.
New Developments in Stencil Laser Technology
The laser machine industry introduced an innovative new concept – low-power laser machines. These low-power machines do not require a cooling system, and we can use them without worrying about temperature control. In addition, they offer energy efficiency, precision, and high quality at a relatively affordable price for PCB manufacturers.
The low-power laser machines can operate at a speed of 100mm/s or higher – this is ideal for PCB manufacturers because it increases production speed. It also allows for creating more cost-effective stencils by reducing the amount of material used. The low-power laser process can also work with several materials, such as stainless steel and aluminum.
Low power laser machines were a big step forward in the PCB industry, especially since they are cheaper than high power lasers. Manufacturers have increasingly been using low-power lasers to make stencils that deliver high precision and excellent quality. The laser cutting of stencils is becoming a new trend in PCB manufacturing, which will likely contribute to the growth of the PCB industry in the future.
Smart Stencils
Stencil manufacturers are constantly working to improve and optimize their products. We can say this for both laser cut and etching-based stencils.
To achieve these goals, manufacturers have strived to make stencils that are mess-free, quick, and easy to use. They have also come up with solutions to make stencils more precise and accurate. We can create laser-cut stencils without the use of expensive software. Stencil manufacturers are also working hard to improve their products’ material quality, durability, and ease of use.
The icing on the cake is that this laser-cut technology is user-friendly and cost-effective, which means it has a high demand among PCB manufacturers.
As the industry continues to grow, more PCB manufacturers are likely to explore the option of laser-cut stencils. Some manufacturers have already begun to use this technology in their PCB production process.
New Fine Grain Performance for Stencils
Many manufacturers have been using fine-grain performance in their laser-cut stencils. This technology has been helpful in laser cutting for decades, but it has only recently become popular among manufacturers because of the increased demand for high-resolution.
Manufacturers can create stencils with finer detail and reduce material waste with fine-grain performance. It also increases the lifespan and durability of the stencil material. The result is less chance of damage to the product during assembly or shipping.
As the PCB industry grows, more manufacturers will use fine-grain performance in their stencils. This is due to its ability to create stencils with a high level of detail. In addition, these stencils can be helpful for various applications that require smaller, detailed designs.
Solder Paste Volume
Stencil manufacturers have worked hard to create stencils that are more efficient and cost-effective. An essential factor in this regard is to produce stencils that are useless material.
One example of a better stencil is a stencil made with solder paste. This type of finish provides excellent adhesion, which results in stencils that are easier to cut, build and use. It also has high performance, which increases the lifespan of the stencil material.
Though solder paste stencils have been around for decades, they are not as popular as other types of stencils. The main reason is the difficulty in manufacturing them. However, the PCB industry has contributed significantly to the growing popularity of solder paste stencils because of the demand for high-quality and efficient laser-cut stencils.
Aperture Registration
Stencil manufacturers are always striving to improve the process of manufacturing stencils. One key goal has been to reduce the material required for laser-cut stencils.
One way companies have achieved this is by creating more precise stencil designs. These designs allow for fine-grain texture and high resolution, which has resulted in better results regarding cutting and producing stencils.
More manufacturers will use better aperture registration in their laser-cut stencils as the PCB industry grows.
Conclusion
Although there is a myriad of benefits to using laser cut stencils, this article only covered the top ten reasons why manufacturers should consider switching to laser cut stencils. In addition, we provided some important information about these stencils that you must consider when deciding whether or not to use them in your manufacturing process.
In the end, you will find that laser-cut stencils are a better choice than etching stencils. The reasons and taking this decision is of course up to you.
