High-dielectric material

Abstract

A bulk dielectric material comprises a solid composite material comprising a solid matrix material and a plurality of filler elements distributed within the matrix material. The bulk dielectric material has, at a frequency greater than 1 MHz, (i) a permittivity having a real part of magnitude greater than 10 and an imaginary part of magnitude less than 3, and (ii) an electrical breakdown strength greater than 5 kV/mm and has a minimum dimension greater than 2 mm.

1 . A method of producing a bulk dielectric material having, at a frequency greater than 1 MHz, (i) a permittivity having a real part of magnitude greater than 10 and an imaginary part of magnitude less than 3, and (ii) an electrical breakdown strength greater than 5 kV/mm, the method comprising distributing a particulate filler material in a matrix material to form a solid composite material having a minimum dimension greater than 2 mm, wherein the method comprises placing a mixture of the filler material and the matrix material within a container and evacuating the container. 
     
     
         2 . The method as claimed in  claim 1 , further comprising the step of mixing the filler material with the matrix material at a temperature above room temperature. 
     
     
         3 . The method as claimed in  claim 1 , further comprising the step of compressing a mixture of the filler material and the matrix material. 
     
     
         4 . The method as claimed in  claim 3 , wherein the mixture is compressed at a pressure of at least 1 GPa. 
     
     
         5 . The method as claimed in  claim 1 , further comprising a step of providing the particles of the filler material with a coating. 
     
     
         6 . The method as claimed in  claim 5 , wherein the coating is a modified surface. 
     
     
         7 . The method as claimed in  claim 6 , wherein the coating is an organosilicate shell. 
     
     
         8 . The method as claimed in  claim 7 , wherein the coating is applied by silylation. 
     
     
         9 . The method as claimed in  claim 5 , wherein the coating is an epoxy shell. 
     
     
         10 . The method as claimed in  claim 5 , wherein the coating is a metal or a metal oxide. 
     
     
         11 . The method as claimed in  claim 5 , wherein the coating is applied under a vacuum. 
     
     
         12 . The method as claimed in  claim 5 , wherein the particles of the filler material contain pores and the coating penetrates into the pores. 
     
     
         13 . The method as claimed in  claim 1 , wherein the bulk dielectric material is built up in a plurality of layers. 
     
     
         14 . The method as claimed in  claim 13 , wherein each of the layers has a minimum dimension greater than 5 mm. 
     
     
         15 . The method as claimed in  claim 1 , wherein the bulk dielectric material is cast in a mold having a minimum dimension greater than 5 mm. 
     
     
         16 . The method as claimed in  claim 15  wherein the bulk dielectric material is cast in a single step.