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Sensible Design: The Rise of Resins in IoT Applications

The Internet of Things (IoT) is a platform enabling embedded devices that are connected to the internet to collect and exchange data with each other. Devices can begin to interact and work with each other, even learning from each other’s experience as humans do. The potential for IoT and connectivity is endless, as everyday objects can connect and share intelligence and knowledge. Some current examples deploying IoT include one of the earliest examples of this technology, wearable technology, which has now vastly extended to encompass the healthcare sector, sports, athletics, and even implantable devices.

Some other areas where IoT applications are experiencing rapid growth include the smart home, health care, smart cities, smart grids, agriculture, connectivity within vehicles, and industrial automation. In this month’s column, I will be exploring how resin chemistries can be incorporated by design engineers facing ever increasing new challenges from IoT applications.

New technology is generally targeted at making our lives better. IoT is all about connecting physical devices wirelessly, using sensors and software to exchange data and facilitate connections and communication.

There are loads of exciting examples of how IoT is helping to improve and sustain the world around us, not just make our day-to-day lives simpler. Smart connected homes can prevent unnecessary energy use with the ability to turn off lights, or control heating/cooling activity remotely. Smart sensors are even more sophisticated, able to measure air quality and send alerts when pollution levels are high, which is a great way to drive communities and governments to combat rising pollution levels and bring health benefits to asthma suffers.

Smart farming involves monitoring the external environment and agricultural processes to automate a response; this makes it possible to reduce the amount to water used to hydrate crops, thus reducing wasteful processes, and focusing on the value-added inputs.

In my work, we have developed potting and encapsulating resins for the protection of electronic devices from challenging environments. One recent collaboration involved protecting an IoT sensor within a fuel storage tank monitoring system.

Are Potting Compounds and Encapsulation Resins Identical?
The terms “potting” and “encapsulation” are used interchangeably. Both describe a simple process of covering a component to provide protection from the threats posed by the external environment. In the case of protecting electronics, typically a one- or two-part resin is poured in its liquid state over components of a circuit board. A curing mechanism takes place; this could be a chemical, thermal, UV, or a moisture cure process, to form a solid resin to sufficiently ruggedize the electronics.

However, if you want to be technical, there is a slight difference between potting and encapsulation processes. Potting describes the scenario where the electronic component, for example a PCBA, is housed within a unit, a “pot.” It would normally be the case where the “potting compound” is poured in to fill the entire housing unit; once cured, the entire system—the electronic component, cured potting compound and the housing unit—become the finished component.

Encapsulation on the other hand, describes a process where the electronic component and cured encapsulation resin are removed from the housing (the pot), and placed into a different assembly; the housing is merely there to act as a temporary mould to pour the resin in place.

Resins for Wearable Technology
Wearable devices are becoming increasingly popular, and by utilising IoT technology, these gadgets are leading us to a better-connected lifestyle. Typically, these devices rely on sensors and use RF signals to transfer information, connect, and communicate with another device. The main challenge for wearable devices is ensuring the delicate sensors and components can continue to function in the environments they are subject to. Consider a smart watch. The sensor must survive several physical interactions; the watch is worn, moved, experiences physical shocks, and may be stretched, plus it is usually exposed to several elements, like water, chemicals, or oils—especially for fitness fanatics tracking all their extreme activities. Clearly these devices must be protected to ensure reliable performance.

IoT is an evolving market where the various performance criteria for components is constantly changing to keep up with the latest developments in technology. Encapsulation resins capable of dissipating heat away from hard-working components clearly add value to a variety of applications.

I hope this has been of interest to those of you involved in IoT and helps make life a bit easier for those who are responsible for making the decisions on protecting components and circuitry. Look for my next column, where I will be exploring resin systems in more detail.

This column originally appeared in the December 2021 issue of Design007 Magazine.

Beth Turner is head of encapsulation resins at Electrolube. To read past columns from Electrolube, click here. Download your free copy of Electrolube's book, The Printed Circuit Assembler's Guide to… Conformal Coatings for Harsh Environments, and watch the micro webinar series “Coatings Uncoated!”