A heat dissipation assembly in which a heat generator and a heat dissipator are integrated via an electrically insulating and thermally conductive sheet, at least one surface of which a thermally conductive grease is applied to, in which the thermally conductive grease is incompatible with the electrically insulating and thermally conductive sheet. Heat from the heat generator such as a semiconductor device or the like can be effectively dissipated while an electrically insulating condition is maintained over a long period of time.