With the rapid development of the electronics industry, the use of PCBs has also increased exponentially. However, its use in different applications means that PCBs are subject to different environmental conditions. Where the PCB is exposed to moisture or harsh chemicals, performance may be of concern. Therefore, the PCB must be coated to protect it from environmental conditions. This protection can be achieved by conformal coating or potting or by encapsulation.
Potting and encapsulation resins go a long way in providing high levels of protection to PCBs. In fact, packaging provides both electrical characteristics and mechanical protection. This high level of protection is ensured by the massive amount of resin that surrounds the entire unit. This is much larger compared to conformal coatings. In fact, potting and encapsulation provide foolproof protection. However, potting and encapsulating resins require testing in many environments in order to determine their specifications and suitability for use. These tests usually involve exposing them to controlled atmospheric conditions over a period of time. The size, weight and appearance of the resin can be seen before and after the test to check for any changes.
In addition to potting and encapsulation resins, conformal coatings can also be applied to protect PCBs. This is done by using it as a membrane. Since the film adopts the profile of the board, it does not cause any dimensional changes or add significant weight. In fact, this is beneficial for conformal coatings because it makes it easy to make devices portable. However, tests are required to evaluate the electrical and mechanical properties of the films in applicable environments. Films need to be tested under conditions such as humidity, temperature, etc. to determine the suitability of the film for this atmospheric condition.
Conformal coating as well as encapsulation and potting are available in different sizes to make them suitable for specific applications. For most standard conditions, conformal coating works well as well as potting and resin encapsulation. However, if the conditions are harsh, the choice of coating will be different. For example, acrylic coatings work well with constant exposure to UV light. However, acrylic coatings may not work as well in conditions with high humidity levels. Under these conditions, non-VOC paints can perform better.
Optimal device performance is obtained through the use of potting and encapsulation resins where substantial mechanical stress or harsh environmental conditions may be present. Silicone or polyurethane resins are known to provide a greater degree of flexibility. In fact, where temperatures are particularly low, polyurethane resins are preferred. They are also ideal for devices submerged in water. In the case of exposure to chemicals, epoxy resins are preferred.
Therefore, it is clear that the choice of coating has a lot to do with the physical environment in which the equipment operates. Conformal coating ratings for parameters such as ease and speed of processing, potting and encapsulating resins are preferred although in harsh climatic conditions. Conformal coatings are also preferred where miniaturization and portability of the device are necessary. Because both offer clear advantages, a thorough evaluation of your unique requirements is essential before deciding on a coating.
Post time: Apr-19-2023