Heat-conductive dielectric polymer material and heat dissipation substrate containing the same

Abstract

A heat-conductive dielectric polymer material includes a thermosetting epoxy resin, a nonwoven fiber component, a curing agent and a heat-conductive filler. The thermosetting epoxy resin is selected from the group consisting of end-epoxy-function group epoxy resin, side chain epoxy function group epoxy resin, multi-functional epoxy resin or the mixture thereof. The thermosetting epoxy resin comprises 4%-60% by volume of the heat-conductive dielectric polymer material. The curing agent is configured to cure the thermosetting epoxy resin at a curing temperature. The heat-conductive filler comprises 40%-70% by volume of the heat-conductive dielectric polymer material. The nonwoven fiber component comprises 1%-35% by volume of the heat-conductive dielectric polymer material. The heat-conductive dielectric polymer material has a thermal conductivity greater than 0.5 W/mK.

1 . A heat-conductive dielectric polymer material, comprising:
 a polymer component comprising a thermosetting epoxy resin, wherein the thermosetting epoxy resin comprises 4%-60% by volume of the heat-conductive dielectric polymer material;   a nonwoven fiber component uniformly dispersed in the polymer component, wherein the nonwoven fiber component comprises 1%-35% by volume of the heat-conductive dielectric polymer material;   a curing agent configured to cure the thermosetting epoxy resin at a curing temperature; and   a heat-conductive filler uniformly dispersed in the polymer component, wherein the heat-conductive filler comprises 40%-70% by volume of the heat-conductive dielectric polymer material;   wherein the heat-conductive dielectric polymer material has a thermal conductivity greater than 0.5 W/mK.   
     
     
         2 . The heat-conductive dielectric polymer material of  claim 1 , wherein the thermosetting epoxy resin is selected from the group consisting of end-epoxy-function group epoxy resin, side chain epoxy function group epoxy resin, multi-functional epoxy resin or the mixture thereof. 
     
     
         3 . The heat-conductive dielectric polymer material of  claim 1 , wherein the nonwoven fiber component is selected from the group consisting of ceramic fiber, organic polymer fiber and the mixture thereof. 
     
     
         4 . The heat-conductive dielectric polymer material of  claim 1 , wherein the nonwoven fiber component is selected from the group consisting of glass fiber, aluminum oxide fiber, carbon fiber, polypropylene fiber, polyester fiber and the mixture thereof. 
     
     
         5 . The heat-conductive dielectric polymer material of  claim 1 , wherein the nonwoven fiber component is a chopped strand fiber. 
     
     
         6 . The heat-conductive dielectric polymer material of  claim 1 , wherein a ratio of CTE in two mutually perpendicular axes of the heat-conductive dielectric polymer material is less than 2.1 at a temperature higher than a glass transition temperature of the polymer component. 
     
     
         7 . The heat-conductive dielectric polymer material of  claim 1 , wherein a ratio of CTE in two mutually perpendicular axes of the heat-conductive dielectric polymer material is less than 1.3 at a temperature higher than a glass transition temperature of the polymer component. 
     
     
         8 . The heat-conductive dielectric polymer material of  claim 1 , wherein CTE of the heat-conductive dielectric polymer material is less than 100×10 −6 /° C. at a temperature higher than a glass transition temperature of the polymer component. 
     
     
         9 . The heat-conductive dielectric polymer material of  claim 1 , wherein the nonwoven fiber component comprises glass fiber and polyester fiber, and a volume ratio of the glass fiber to the polyester fiber is in the range between 0.3 and 5. 
     
     
         10 . The heat-conductive dielectric polymer material of  claim 1 , wherein the nonwoven fiber component comprises at least two glass fibers of different ratios of length to diameter. 
     
     
         11 . The heat-conductive dielectric polymer material of  claim 1 , wherein the nonwoven fiber component comprises a glass fiber of a ratio of length to diameter ranging from 50 to 10000. 
     
     
         12 . The heat-conductive dielectric polymer material of  claim 1 , wherein the thermosetting epoxy resin is uncured liquid epoxy resin or polymerized epoxy resin. 
     
     
         13 . The heat-conductive dielectric polymer material of  claim 1 , wherein the thermosetting epoxy resin comprises mono-functional group, bi-functional group, tri-functional group, multi-functional group or the mixture thereof. 
     
     
         14 . The heat-conductive dielectric polymer material of  claim 1 , wherein the thermosetting epoxy resin comprises phenolic epoxy resin or bisphenol A epoxy resin. 
     
     
         15 . The heat-conductive dielectric polymer material of  claim 1 , wherein the curing agent has a curing temperature higher than 80° C. 
     
     
         16 . The heat-conductive dielectric polymer material of  claim 1 , wherein the polymer component further comprises a thermoplastic, and the thermoplastic and the thermosetting epoxy resin are mutually soluble prior to curing and form an inter-penetrating network structure after curing. 
     
     
         17 . The heat-conductive dielectric polymer material of  claim 16 , wherein the thermoplastic comprises 1% to 40% by volume of the heat-conductive dielectric polymer material. 
     
     
         18 . The heat-conductive dielectric polymer material of  claim 16 , wherein the thermoplastic comprises bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin or the mixture thereof. 
     
     
         19 . A heat dissipation substrate, comprising:
 a first metal layer;   a second metal layer; and   a heat-conductive dielectric polymer material layer comprising the heat-conductive dielectric polymer material of  claim 1 , wherein the heat-conductive dielectric polymer material layer is sandwiched between and in physical contact with the first metal layer and the second metal layer;   wherein the heat-conductive dielectric polymer material layer can withstand a voltage greater than 2000V in the case that the heat-conductive dielectric polymer material layer has a thickness of 0.1 mm.   
     
     
         20 . The heat dissipation substrate of  claim 19 , wherein interfaces between the heat-conductive dielectric polymer material layer and the first and second metal layers comprise at least one micro-rough surface having a plurality of nodular protrusions. 
     
     
         21 . The heat dissipation substrate of  claim 19 , wherein peeling strength between the heat-conductive dielectric polymer material layer and the first or the second metal layer is greater than 0.8 kg/cm.