Fully immersed in a speciality grade of oil, commonly used in high-performance vehicles, the sensor was being subjected to trials to determine its ability to function at elevated oil temperatures (up to a maximum of 170 °C), when the original encapsulation resin began showing signs of failure. This resin not only failed to withstand the high oil temperatures over extended periods of time, but was also losing its adhesion to the sensor’s metal alloy housing when thermally cycled. The company suggested that its new chemically resistant epoxy resin might provide a solution to these problems. It is a two-part epoxy encapsulation resin offering high resistance to a wide variety of chemicals, including solvents and fuels. The 100 percent reactive system contains neither solvents nor non-reactive diluents, thus offering the highest level of performance when deployed in harsh chemical and high temperature environments. Moreover, the fully RoHS-2 compliant (2011/65/EU) ER1455 resin provides excellent adhesion to a wide variety of substrates, a property that is not compromised by elevated temperatures or when used in the presence of aggressive chemicals, solvents, fuels and lubricants. ER1455 has now been fully tested by the customer and has been found to maintain excellent adhesion to the sensor housing in the presence of the specialty oil, even at its maximum duty temperature and throughout a campaign of thermal cycling. The resin has subsequently been approved and implemented by the customer in their vehicle applications. The encapsulation resins are available in epoxy, polyurethane and silicone formulations with specific properties designed to protect and insulate printed circuit boards (PCBs) and electronic components from the threats of harsh and challenging environments, including moisture, vibration, thermal or physical shock and general contamination.
