Wikipedia
BT-Epoxy belongs to the group of thermoset resins used in printed circuit boards (PCBs). It is a mixture of epoxy resin, a common raw material for PCBs and BT resins. BT stands for Bismaleimide-Triazine resin. This is in turn a mixture of bismaleimide, which as such is also used as a raw material for PCBs and cyanate ester. Three cyano groups of the cyanate ester are trimerized to a triazine ring structure, hence the T in the name. In presence of a bismaleimide the double bond of the maleimide group can copolymerize with the cyano groups to heterocyclic 6-membered aromatic ring structures with two nitrogen atoms ( pyrimidines). The cure reaction occurs at temperatures up to 250 degrees C, and is catalyzed by strongly basic molecules like Dabco (diazabicyclooctane) and 4-DMAP (4-dimethylaminopyridin). Products with very high glass transition temperatures (T)- up to 300 degrees C - and very low dielectric constant can be obtained. These properties make these materials very attractive for use in PCBs.
Category:Synthetic resins