EMI Shielding protects drones

| Environmental Testing

Commercial drones are susceptible to radio frequency interference both internally and from external sources

Sprayable shielding material protects drones from external and internal Radio Frequency Interference

Parker Chomerics has launched has come up with dual techniques to help in the protection of drones from both electromagnetic interference and overheating.

Drones operating near mobile phone towers, buildings, antennas, high-voltage power lines and other obstacles can be affected by serious electromagnetic interference (EMI), compromising their performance and safety.

Another major issue is overheating, caused by the high processing load on the drone’s electronics and the powerful rotors.

EMI protection

Meeting the EMI challenges demands highly effective shielding to protect the internal electronics from malfunctioning.

To be commercially successful, drones need to be mass produced, so any shielding solution should allow use by automated methods to keep assembly costs down. Drones also require solutions that can reduce weight, as well as allowing effective connections from drone to controller. Weather resistance is also a key characteristic.

To meet these requirements, Parker Chomerics CHOFORM 5575, Form-In-Place (FIP) EMI gasket material is used. This robotically dispensed material can be directly applied onto the aluminium casting of the drone to act as a barrier, stopping the electrical circuits talking to each other and causing premature failure. CHOFORM 5575 is a moisture cured silver-plated aluminium filled silicone material offering up to 80 dB shielding effectiveness between 200 MHz and 12 GHz.

It is specifically designed to provide excellent conductivity and EMI shielding for electronic enclosures employed in high temperature applications up to 125 C. Based on a quick curing silicon system that displays excellent flow properties, it is perfect for dispensing on small complex part geometries in high volume manufacturing applications.

With no mixing or weighing needed, CHOFORM 5575 is supplied as a single component, making it easy to apply in a wide range of applications, including densely populated electronics packaging; castings, machined metal and conductive plastics enclosures; automotive sensor housings; and military and aerospace electronics.

As an internal elastomer seal, CHOFORM 5575 prevents electrical interference between one part of the drone’s electronic circuitry and another. It also acts as a Faraday cage to shield the internal electronics from external electric fields such as those from mobile phone towers and power distribution cables.

This method is particularly suited to drones as using an FIP gasket saves up to 60% of space and weight in the drone housing, as flanges can be as narrow as 0.025 in (0.76mm). It also has a high resistance to corrosion when dispensed onto aluminium, preventing galvanic corrosion in the electronic enclosure.

Thermal Protection

Parker Chomerics hasn’t just addressed the hazards of Radio Frequency Interference for drones but has also developed a thermal solution to enable the drone to operate efficiently by preventing the risk of overheating.

To mitigate thermal effects, Parker Chomerics has developed THERM-A-GAP GEL 37. Offering a 3.7 W/m-K thermal conductivity, this product is used to conduct the heat from the chipset to the drone’s enclosure.

This pre-cured, single component thermal gel material can be dispensed directly onto the chipset by automation, significantly reducing production time. THERM-A-GAP GEL 37 has a soft, paste consistency, eliminating any stress on the electronic components and requires no mixing or curing.

Both of the products are designed to be applied during the manufacturing process of the drone as both the EMI shielding and the thermal solution are added to the product through automated methods using dispensing robots. This method helps to improve manufacturing productivity and reduce time to market.

Jonathan Newell
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