Dielectric composite material

Abstract

A dielectric composite material containing a toughened benzocyclobutene resin and at least about 50% by weight of an inorganic filler. Also electronic packages having at least one conductive layer and at least one layer of the dielectric composite material. The dielectric composite material can have a dielectric constant less than about 3.5, and a dielectric loss of less than about 0.004.

1 . A dielectric composite material suitable for use in electronic packages, said composite material having a dielectric constant less than about 3.5, and a dielectric loss of less than about 0.004, the composite material including a toughened benzocyclobutene resin, and from about 50% to about 75% by weight of at least one inorganic particulate filler, the resin and the filler being compatiblized by means of a compatibilizing agent selected from a surfactant, a dispersing agent, and a silane coupling agent.  
   
   
       2 . A dielectric composite material according to  claim 1  wherein said benzocyclobutene resin and said filler are compatibilized by means of a silane coupling agent.  
   
   
       3 . A dielectric composite material according to  claim 2  wherein said silane coupling agent is selected from the group consisting of vinyltriethoxysilane, vinyltriacetoxysilane, 7-octenyltrimethoxysilane and mixtures thereof.  
   
   
       4 . A dielectric composite material according to  claim 3  wherein said silane coupling agent further comprises an additional silane selected from the group consisting of hexyltrimethoxysilane, octyltrimethoxysilane, pentyltrimethoxysilane, phenyltrimethoxysilane, and mixtures thereof.  
   
   
       5 . A dielectric composite material according to  claim 1  wherein said at least one inorganic particulate filler is selected from the group consisting of silica, alumina, glass and quartz.  
   
   
       6 . A dielectric composite material according to  claim 1  wherein said at least one inorganic particulate filler is a particulate silica having an average particle size of less than or equal to ten percent of the thickness of a layer of the dielectric composite material.  
   
   
       7 . A dielectric composite material according to  claim 1  wherein a layer formed from said dielectric composite material has a thickness of from about 0.5 micrometer to about 50 micrometers.  
   
   
       8 . A dielectric composite material according to  claim 1  wherein a layer formed from said dielectric composite material has an adhesion to low profile copper of at least about 0.35 N/mm.  
   
   
       9 . A dispersion comprising a toughened benzocyclobutene resin, at least one inorganic particulate filler having a dielectric constant of less than or equal to 4.0, and a dielectric loss of less than 0.001; a silane coupling agent; and a non-polar solvent.  
   
   
       10 . A dispersion according to  claim 9  wherein said inorganic particulate filler has a surface treated with a silane coupling agent selected from the group consisting of vinyltriethoxysilane, vinyltriacetoxysilane, 7-octenyltrimethoxysilane, and mixtures thereof.  
   
   
       11 . A dispersion according to  claim 9  wherein said non-polar solvent is selected from the group consisting of mesitylene, toluene, and mixtures thereof.