New UV-Curable Epoxies for Dam & Fill Applications

摘要

The "dam & fill" process with two materials is mainly used in cases where a component needs to be protected with either an optically-transparent or opaque encapsulant or if a conventional glob-top material is too viscous to flow around and underneath fine wires. Optically transparent encapsulants usually have a low viscosity. A dam is therefore applied around the component first to prevent the potting material from flowing over the substrate. The product Epo-Tek OG116-31 launched by JP Kummer is a UV-curable epoxy. Due to its thixotropic nature it is often used as a dam. It can be cured with UV-light in a very short time. Afterwards the encapsulant - either also a UV-cure or a thermoset material - can be applied. Whilst OG142-87 is typically used for a UV fill, both products have a high glass transition temperature (Tg >100 °C).