Protection has become an utmost part of every advancement amidst severe climate change. Also, we can’t deny that tech gadgets require strong resistance against harsh weather, rain, sun exposure, or electromagnetic currents. Resins and coatings protect the Printed Circuit Boards to ensure their compatibility. It helps to focus on what environmental factors can affect the PCB from the outside and manufacture PCBs accordingly. Therefore, manufacturers pay comprehensive attention to designing PCBs to meet the growing market demands and mitigate the factors affecting their functionality.
Now you must be thinking about what coating will be the best for your provided industrial conditions. Then, after checking the EMI standpoints, consider the coated or resin PCB. These are simply the organic polymers that serve as an additional covering layer on the PCBs applied to provide protection. It serves as a lifesaver for the owners whose devices are prone to harsh environmental conditions. Yet, the answer to what’s better: coating or Resin PCB is, as always, depends on your requirements. This article comprehensively discusses these two protective solutions for PCBs separately and collectively to offer you a detailed understanding and aid you in deciding what’s suitable for your system.
The short-term protective Coating on PCBs:
- Properties:
Coatings are clear and thin film-type layers, adding not much weight to the device. It ensures the components on PCB are visible and protects it without increasing the PCBs weight. The coating is around 25 to 100 microns thin with high and ultra-clear visibility. It allows the manufacturers to tackle possible issues of the PCB and change the components after their application.
- Environmental Resistance:
Coating PCBs are good for environments that call for less exposure to heat, chemicals, or tough surroundings. Long-term exposure may cause damage to the coated PCB. An extended exposure can even result in failed functionality. However, the conformal coating offers no stress or weight to the electrical components. So, you can play with pins and legs on such PCBs without causing any inconvenience.
- Application procedure:
It is easier to apply coating on the PCBs. You can apply the thin film coating with the brush, spray, or with your hands dipped in the solution. It only requires one step, less drying time, and one material to coat the PCB, making it convenient for the manufacturers designing PCBs. For good measure, you can also choose mechanical methods for coating application on the PCBs.
- 1K and 2K coating components:
However, the one-component coatings usually involve solvents considering the required viscosity. Remember that these are the traditional coatings that have a high quantity of solvents to reduce the viscosity of the base resin. But, the advancement has brought a two-component coating made of epoxy or polyurethane coatings that contain near to no volatile organic compounds and solvents. These have the properties of resin layering enclosed in the conformal coating. The manufacturers consider these solids as they give the dry thin film as a coating, unlike the wet layer of solvents. It implies additional protection and flexibility, ensuring more protection and adherence to even the delicate components of the PCB. Yet, it also becomes a little time-consuming and challenging as resin, owing to the two-part manufacturing.
Resin layer – the ultimate long-term solution:
- Properties:
Resin PCBs, on the other hand, are superior and secured for long-term exposures. Yet, it adds trade-off weight and thickness to the PCBs because of the quantitative application, also adding more to its cost. The manufacturers rule the tip on 0.5 mm at the thinner side of the spectrum but apply a thicker layer as much as possible. This thick application increases weight but also provides similar protection on prolonged immersion. More to this, you won’t be able to modify your PCB designs, as Resin PCBs can’t adapt to other designs than traditional linear structures.
- Prolonged protection:
On the pleasant side, this double resin protection makes the PCBs more secure and compatible with harsh environments for extended periods. The Resin PCBs can also sustain electrical shocks as the current vanish within the protective layer than associating with the volts, reducing destruction.
- 2K components:
Resin PCBs are challenging to repair post-manufacturing owing to the hard protective layer. The rationale is it generally involves two components: resin and hardener that chemically combine to form a cross-linked organic polymer. The layering also requires two steps or involves two-stage coating. Note that Resins also contain high viscosity levels but no VOC because of no spray applications.
- Application Process:
Extensive care is required when applying resins as the curing process can heat the resin PCBs or even result in failure. Ensure that you use enough quantity in the first layering to maintain balance and avoid excessive heat generation. It’s simply like a make-a-paste procedure in which the manufacturer mixes the components in the required ratio and applies them for fine finishing. So, it seems not a good employment option and even makes the manufacturing a little tough and timely if carried out manually. Yet, thanks to the advancements, one can now carry the resin application mechanically by employing an automatic dispensing system to ease the process of mixing and coating in a consistent amount.
Additional security: advantage or a concern?
If you want to keep the PCB design a secret with ultimate protection, Resin PCBs are good to go. You can use black resin to hide the PCB components, even if it doesn’t require additional environmental protection. It means if someone tries to remove resin layering from the PCB, it will destroy the design, crazy right? It’s this sturdy and aggressive protection that protects the components from unveiling environmental factors. However, remember that resin will rip your PCB apart even if you try to remove the resin layer.
Ask yourself before choosing one:
It is significant to analyze the system requirements and the surroundings to ensure a suitable decision. So, you can ask the following questions for a thorough understanding before you choose coating or Resin PCB. These questions can be about:
- Environmental surroundings
Where will you place your device, and what factors can affect PCB there? Resin PCB has the strong compatibility to sustain prolonged harsh exposure. Coating PCBs aren’t suitable for such environments. Yet, you can employ them in calm atmospheres, owing to their delicate protective layer that offers short-term protection.
- Enclosure
Does your device require considerable protection or want minimal? Substantial protection calls for resin layering, and if it already has one and just needs extra protection, you can apply a thin coating. Most PCBs have a housing enclosure serving as their primary protective layer, so the coating suffices for such circuit boards. It can protect you from humidity and condensation. Yet, Resin PCBs are self-sufficed circuit boards that don’t need any additional enclosure.
- Electrical power
Is your device prone to high voltage conditions? If yes, you should employ Resin PCB. Resin PCB is suitable for areas prone to high voltage or electric shock. Most manufacturers use Resin PCBs in heavy electronic devices and machinery because of their dielectric nature to reduce arcing caused by electrical shocks.
- Weight of the PCB
Does the weight or thickness of the PCB matter for your prototype? Consider that Resin PCB is heavy-in-weight, and conformal coating only gives it a minimal look without adding much to it. You should choose according to your needs.
- Manufacturing Process
Does manufacturing affect your design and decisions in any way? Your answer can help you to decide what to choose. Resin PCB requires more manufacturing steps and time than coating PCB. You must know this by now, as the manufacturers apply the resin in two layers to ensure safety and efficiency. The calculations of the component’s proportion and application are time-consuming. The conformal coating requires a one-step procedure to apply to the PCB, and you are ready to go. However, the advanced 2K coating also leads to similar manufacturing complexities as Resin. So, choose wisely and accordingly.
I believe all these questions are already part of the designer’s mind even before manufacturing begins. Yet, the reinforcement of these queries can aid you in keeping the balance and track when designing the PCBs. Remembering the differences between resin PCB and coating is also significant to choose between more or less protection to ensure efficiency. Planning and Analysis powers up the designing game, leading you to reach the top.
Conclusion:
So, these highlighted properties of the coating and Resin PCBs emphasize the need to analyze your system and the requirements to make the right decision. The coating has different functions and drawbacks. The same goes for the Resin PCB. Adding more to the complications, now several devices incorporate 2K coating PCBs because of their advanced properties. Yet, you can only apply these with the specific equipment and in the range of 200-400 microns. So, if you want a combined effect of coating and resin or to reduce the cons of either, you can choose 2K conformal coating PCBs. However, irrespective of the protection type, the PCBs require frequent cleaning to avoid contamination from surpassing the protective layer.
