Issue link: https://iconnect007.uberflip.com/i/1315894
28 DESIGN007 MAGAZINE I DECEMBER 2020 One of the most frequently asked questions we receive from customers is, "Which is better to protect my PCB: a coating or a resin?" PCBs are found in many domestic, industrial, auto- motive, and military devices and require pro- tection from their environment. Lack of pro- tection can lead to reduced performance or, in the worst case, a complete failure. Protection can be offered in the form of conformal coat- ings or potting and encapsulation resins. In this month's column, I will demystify why one may be more suitable for your applica- tion than the other. Like any good engineering answer, it depends on the degree of environ- mental protection required. The first point for consideration is often the design of any hous- ing within which the PCB will be enclosed. If an assembly is enclosed in a housing that is designed to be the primary environmental pro- tection, then a conformal coating is often used to provide a back-up to the primary protection provided by the housing. Where the housing is not suitable or capable of providing primary protection of the assembly from its operating environment, then most times, a resin might be a better choice. If we look at both coatings and resins, then we can consider what is common between the two. Both are generally organic polymers, which can cure to form an electrically insulat- ing layer that provides some degree of chemi- cal and thermal resistance. There is a degree in commonality in the chemistry of the polymers used, with acrylic, epoxy, polyurethane, and silicone being the most often encountered. Without further ado, let's explore coatings and resins in more detail in our five-point format. 1. What is an encapsulation resin? Potting and encapsulation resins offer the highest level of protection for PCBs. Resins can be applied from 0.5 millimetres upwards To Coat or Encapsulate: Making An Informed Choice for Electronics Protection Sensible Design by Phil Kinner, ELECTROLUBE