Amid the increasing climate change, protection has become a top priority for every advancement. Moreover, we cannot deny that tech products require strong resistance to harsh weather, rain, sun or electromagnetic currents. Resins and coatings protect printed circuit boards to ensure their compatibility. This helps focus on which environmental factors affect the PCB from the outside and manufacture the PCB accordingly. Therefore, manufacturers pay comprehensive attention to the design of PCBs to meet the growing market demands and mitigate the factors that affect their functionality.

Now, you must be thinking about which coating is best for the industrial conditions you have to offer. Then, consider PCB coating or resin PCBs after checking the EMI point of view. These are simply organic polymers that are used as an additional covering layer on the PCB to provide protection. It can be a lifesaver for users whose devices are susceptible to harsh environmental conditions. However, the answer to which coating or resin PCB is better, as always depends on your requirements. This article comprehensively discusses these two PCB protection solutions, both individually and collectively, to provide you with a detailed understanding and help you decide which solution is right for your system.

Short-term protective on PCB coating

Features:
Coating is a transparent film layer that does not add much weight to the device. It ensures that the components on the PCB are visible and protects it without adding weight to the PCB. The coating thickness is about 25 to 100 microns and has high clarity. It allows manufacturers to solve possible problems with the PCB and replace components after application.

Environmental resistance:
Coated PCBs are suitable for environments that require less exposure to heat, chemicals, or harsh environments. Long-term contact may damage the coated PCB. Prolonged contact may even cause functional failures. However, conformal coating does not put pressure or weight on electrical components. Therefore, you can use pins and pins on such PCBs without any inconvenience.

Application procedure:
Applying coating on PCBs is easier. You can apply the thin film coating using a brush, sprayer, or by dipping your hands into the solution. It coats the PCB in just one step, less drying time, and one material, which provides convenience for manufacturers designing PCBs. To be foolproof, you can also choose a mechanical method to apply the coating on the PCB.

1K and 2K coating composition:
However, one-component coatings usually involve solvents, given the required viscosity. Remember, these are traditional coatings that have a lot of solvents to reduce the viscosity of the base resin. However, advancements have brought about two-component coatings made of epoxy or polyurethane coatings that are virtually free of VOCs and solvents.

They have the properties of resin layering wrapped in a conformal coating. Manufacturers consider these solid because they apply a dry film as a coating, unlike a wet solvent layer. It means extra protection and flexibility, ensuring more protection and adhesion to the delicate components of the PCB. However, due to being a two-part manufacturing, it also becomes a bit time-consuming and challenging like resin.

Resin Layer – The Ultimate Long-Term Solution:

Features:
On the other hand, resin PCBs are superior and are suitable for long-term exposure. However, due to the quantitative application, it adds weight and thickness to the PCB, which also increases the cost. Manufacturers keep the tip within 0.5 mm, which is on the thinner side of the spectrum, but apply thicker layers as much as possible. This thick layer application adds weight but also provides similar protection during long-term immersion. In addition, you will not be able to modify the PCB design because resin PCBs cannot adapt to other designs other than traditional linear structures.

Extended Protection Time:
On the bright side, this double resin protection makes the PCB safer and able to adapt to harsh environments for a long time. Resin PCBs can also withstand electric shocks because the current disappears within the protective layer instead of being associated with the voltage, reducing damage.

2K Components:
Since resin PCBs have a hard protective layer, they are very difficult to repair after manufacturing. The reason for this is that it usually involves two components: resin and hardener, which are chemically combined to form a cross-linked organic polymer. Layering also requires two steps or involves two-stage coating. Note that resin also has a high viscosity level, but since there is no spray application, it is VOC-free.

Application Process:
Extra care is required when applying resin because the curing process may heat up the resin PCB and even cause failure. Make sure to use enough in the first layer to maintain balance and avoid excessive heat generation. It’s like a procedure for making paste, where the manufacturer mixes the ingredients in the required proportions and then applies them to the surface for fine processing. Therefore, it does not seem to be a good choice for employment if done manually, and even makes manufacturing a bit difficult and time-consuming. However, due to technological advancements, resin application can now be done mechanically by using an automated dispensing system to simplify the process of mixing and coating in consistent amounts.

Extra Security: Advantage or Concern?

If you want to keep your PCB design confidential with ultimate protection, then resin PCBs are a good choice. You can use black resin to hide PCB components even if it does not require additional environmental protection. This means that if someone tries to remove the resin layer from the PCB, the design will be destroyed, crazy, right? It is this strong and powerful protection that protects the components from environmental factors. However, remember that the resin will tear your PCB even if you try to remove the resin layer.

Ask yourself before choosing:

Analyzing system requirements and environment is very important to ensure that you make a suitable decision. Therefore, before choosing a coated or resin PCB, you can ask the following questions for a thorough understanding. These questions may involve:

Environmental surroundings
Where will you place your device? What factors will affect the PCB there? Resin PCBs have strong compatibility and can withstand harsh environments for a long time. Coated PCBs are not suitable for such environments. However, you can use them in calm environments as they have a delicate protective layer that provides short-term protection.

Enclosure
Does your device require a lot of protection or only minimal protection? A resin layer is required for a lot of protection, and if it already has a resin layer and only requires additional protection, you can apply a thin coating. Most PCBs have an enclosure as their primary protective layer, so coating is enough for such boards. It protects you from moisture and condensation. However, resin PCBs are self-sufficient boards and do not require any additional enclosure.

Electricity
Is your device susceptible to high voltage? If yes, you should use resin PCBs. Resin PCBs are suitable for areas that are susceptible to high voltage or electric shock. Most manufacturers use resin PCBs in heavy electronic devices and machinery because they have dielectric properties that reduce arcing caused by electric shock.

PCB Weight
Is the weight or thickness of the PCB important for your prototype? Considering the heavy weight of resin PCBs, conformal coating will only give it a minimalist look without adding much functionality. You should choose based on your needs.

Manufacturing Process
Does manufacturing affect your design and decision in some way? Your answer can help you decide what to choose. Resin PCBs require more manufacturing steps and time than coated PCBs. You must know this by now because manufacturers apply resin in two layers to ensure safety and efficiency. Calculating the proportions and application of components is time-consuming. Conformal coating requires a one-step procedure to be applied to the PCB, and then you are good to go. However, advanced 2K coatings also lead to similar manufacturing complexities as resins. So choose wisely and accordingly.

I believe that all these questions are already part of the designer’s mind before manufacturing begins. However, strengthening these questions can help you keep a balance and track when designing PCBs. Remembering the differences between resin PCBs and coatings is also important to choose more or less protection to ensure efficiency. Planning and analysis can enhance design capabilities and lead you to the top.

Therefore, these prominent characteristics of coating and resin PCBs emphasize the necessity of analyzing the system and requirements to make the right decision. Coatings have different functions and disadvantages. The same is true for resin PCBs. To make it more complicated, some devices now adopt 2K coated PCBs due to their advanced characteristics.

However, you can only apply them in the range of 200-400 microns using specific equipment. Therefore, if you want the combined effects of coating and resin or reduce the disadvantages of both, you can choose 2K conformal coated PCBs. However, regardless of the type of protection, PCBs need to be cleaned frequently to avoid contaminants from overtaking the protective layer.