Heat dissipation substrate for electronic device

Abstract

A heat dissipation substrate for an electronic device comprises a first metal layer, a second metal layer, and a thermally conductive polymer dielectric insulating layer. A surface of the first metal layer carries the electronic device, e.g., a light-emitting diode (LED) device. The thermally conductive polymer dielectric insulating layer is stacked between the first metal layer and the second metal layer in a physical contact manner, and interfaces therebetween include at least one micro-rough surface with a roughness Rz larger than 7.0. The micro-rough surface includes a plurality of nodular projections, and the grain sizes of the nodular projections mainly are in a range of 0.1-100 μm. The heat dissipation substrate has a thermal conductivity larger than 1.0 W/m·K, and a thickness smaller than 0.5 mm, and comprises (1) a fluorine-containing polymer with a melting point higher than 150° C. and a volume percentage in a range of 30-60%, and (2) thermally conductive filler dispersed in the fluorine-containing polymer and having a volume percentage in a range of 40-70%.

1 . A heat dissipation substrate for an electronic device comprising:
 a thermally conductive polymer dielectric insulating layer comprising:
 (1) a fluorine-containing polymer with a melting point higher than 150° C. and a volume percentage in a range of 30-60%; and 
 (2) thermally conductive filler dispersed in the fluorine-containing polymer and having a volume percentage in a range of 40-70%; 
   a first metal layer having a micro-rough surface which is in direct physical contact with one surface of the thermally conductive polymer insulating layer, and consists essentially of nodules which protrude from the surface by a distance of 0.1 to 100 microns with roughness Rz larger than 7.0; and   a second metal layer having a micro-rough surface which is in direct physical contact with the other surface of the thermally conductive polymer insulating layer, and consists essentially of nodules which protrude from the surface by a distance of 0.1 to 100 microns with roughness Rz larger than 7.0;   wherein the heat dissipation substrate has a thermal conductivity larger than 1.0 W/m·K.   
     
     
         2 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the first metal layer has a thickness smaller than 0.1 mm. 
     
     
         3 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the second metal layer has a thickness smaller than 0.2 mm. 
     
     
         4 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the fluorine-containing polymer has a melting point higher than 220° C. 
     
     
         5 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the thermally conductive filler has a volume percentage of 45-65%. 
     
     
         6 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein tensile strength between the thermally conductive polymer dielectric insulating layer and the first and second electrode layers is larger than 8 N/cm. 
     
     
         7 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein a surface of the heat dissipation substrate neither is ruptured nor has cracks when the heat dissipation substrate is 1 cm wide and is bent 180 degree along the exterior circumference of a metal rod with a diameter of 5 mm. 
     
     
         8 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the heat dissipation substrate has a withstand voltage larger than 3 kV. 
     
     
         9 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the fluorine-containing polymer is selected from the group consisting of poly vinylidene fluoride and polyethylenetetrafluoroethylene. 
     
     
         10 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the fluorine-containing polymer is selected from the group consisting of poly(tetrafluoroethylene), tetrafluoroethylene-hexafluoro-propylene copolymer, ethylene-tetrafluoroethylene copolymer, perfluoroalkoxy modified tetrafluoroethylenes, poly(chlorotri-fluorotetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene copolymer, poly(vinylidene fluoride), tetrafluoroethylene-perfluorodioxole copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, and tetrafluoroethylene-perfluoromethylvinylether with cure site monomer terpolymer. 
     
     
         11 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the thermally conductive filler is nitride or oxide. 
     
     
         12 . The heat dissipation substrate for an electronic device in accordance with  claim 11  wherein the nitride is selected from the group consisting of zirconium nitride, boron nitride, aluminum nitride, and silicon nitride. 
     
     
         13 . The heat dissipation substrate for an electronic device in accordance with  claim 11 , wherein the oxide is selected from the group of aluminum oxide, magnesium oxide, zinc oxide, and titanium dioxide. 
     
     
         14 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the heat dissipation substrate is irradiated by 0-20 Mrads, so as to make the thermally conductive polymer dielectric insulating layer cross-linked and cured. 
     
     
         15 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the electronic device is a light-emitting diode device. 
     
     
         16 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the first metal layer comprises copper. 
     
     
         17 . The heat dissipation substrate for an electronic device in accordance with  claim 1 , wherein the second metal layer comprises aluminum.