Issue link: https://iconnect007.uberflip.com/i/1464168
APRIL 2022 I DESIGN007 MAGAZINE 87 5. What sort of testing programmes have these new bio-resins been subjected to? e bio-resins have been tested extensively. ere is a common perception that going green, or bio-based, means there will be some sort of compromise on quality of performance. For a new product line to be relatively dis- ruptive and have a high bio-derived content, extreme testing was essential to generate valu- able data. e barriers to entry for encapsu- lation resins in the electronics market is rela- tively low when compared with other rugged- ization techniques such as conformal coatings. Typically, a lot of resin qualification comes down to customers screening for their own unique application; the resin either passes or fails. ere is no formal industry standard that outlines a specific test criterion; this is mainly because every application is truly unique. To recall just a handful of the tests these new bio-resins have been subject to: • Surface insulation resistance testing (SIR) on copper and tin B-24 test coupons at 85°C/85% RH, to ensure the encapsulant pictogram (GHS08/health hazard). We can replace this hardener with alternative reactive agents derived from bio-sources which do not contain the GHS08 pictogram and are much safer for operators to use. 4. Do bio-resins lend themselves to RF applications? ey most certainly do. We have another with bio-sourced content of over 60%, which is an unfilled polyurethane resin that has found success in sensor applications as it has a low dielectric constant (relative permittiv- ity). Most IoT communication takes place in blocks of the radio frequency spectrum; a low dielectric constant is essential to ensure the resin does not interfere with the RF sig- nal. It provides excellent electrical insulation across a wide operating temperature range, which is required for long-term performance, and has a high toughness, offering protection from physical shock and vibration. It has good resistance to lots of deleterious substances, making it the ideal choice for ruggedizing sen- sors exposed to harsh environments.