Patent Title: POLYMER COMPOSITE THERMAL INTERFACE MATERIAL WITH HIGH THERMAL CONDUCTIVITY

 Number/Link: WO2016/079627

Applicant/Assignee: IBM

Publication date: 26-05-2016

“Gist”: PU-Epoxy IPN particle composites show improved thermal conductivity

Why it is interesting: The application is about thermally conductive adhesives for use with electronic components. Commonly these materials consist of polymers filled with thermally- (but not electrically-) conductive particles such as AlN, BN and ZnO. According to the invention the thermal conductivity of these composites can be improved by using a polyurethane-epoxy true interpenetrating polymer network (IPN) as the matrix. In the examples a MDI-polycaprolactone prepolymer is mixed with a BPA diglycidylether prepolymer and boron nitride (BN) particles and crosslinked using trimethylolpropane and imidazole.  The thermal conductivity of the composite shows a synergy, meaning that it is clearly higher than the conductivities of both the PU or EP composites. The synergy is said to be due to an enhanced distribution of the BN particles and (because this is IBM and they are very clever) due to enhanced phonon scattering.

Bisphenol-A diglycidylether