Resin sheet and resin multilayer substrate

Abstract

A resin sheet that contains one or more kinds of resin materials and a liquid crystal polymer, wherein a weight of the liquid crystal polymer is less than a total weight of the one or more kinds of resin materials. The resin sheet has a thermal expansion coefficient in a plane direction smaller than a thermal expansion coefficient in the plane direction of a comparative resin sheet containing the one or more kinds of resin materials and not containing the liquid crystal polymer.

1 . A resin sheet comprising:
 one or more kinds of resin materials; and   a liquid crystal polymer,   wherein a weight of the liquid crystal polymer is less than a total weight of the one or more kinds of resin materials, and   the resin sheet has a thermal expansion coefficient in a plane direction smaller than a thermal expansion coefficient in the plane direction of a comparative resin sheet containing the one or more kinds of resin materials and not containing the liquid crystal polymer.   
     
     
         2 . The resin sheet according to  claim 1 , wherein a relative permittivity of the one or more kinds of resin materials is smaller than a relative permittivity of the liquid crystal polymer. 
     
     
         3 . The resin sheet according to  claim 1 , wherein a dielectric loss tangent of the one or more kinds of resin materials is smaller than a dielectric loss tangent of the liquid crystal polymer. 
     
     
         4 . The resin sheet according to  claim 1 , wherein the liquid crystal polymer contains fibrous particles. 
     
     
         5 . The resin sheet according to  claim 4 , wherein the fibrous particles have an aspect ratio of 10 times or more, the aspect ratio being a ratio of a length in a longitudinal direction to a fiber diameter, and have an average diameter of 1 μm or less. 
     
     
         6 . The resin sheet according to  claim 4 , wherein a thermal expansion coefficient in a longitudinal direction of a main chain structure of the liquid crystal polymer containing the fibrous particles is negative. 
     
     
         7 . The resin sheet according to  claim 1 , wherein a highest melting point among melting points of the one or more kinds of resin materials is lower than a melting point of the liquid crystal polymer by 30° C. or more. 
     
     
         8 . The resin sheet according to  claim 1 , wherein the one or more kinds of resin materials are a fluororesin. 
     
     
         9 . The resin sheet according to  claim 8 , wherein the fluororesin is perfluoroalkoxyalkane. 
     
     
         10 . The resin sheet according to  claim 1 , wherein the thermal expansion coefficient of the resin sheet in the plane direction is 5 ppm/° C. to 20 ppm/° C. 
     
     
         11 . The resin sheet according to  claim 1 , wherein the thermal expansion coefficient of the resin sheet in the plane direction is 10 ppm/° C. to 20 ppm/° C. 
     
     
         12 . The resin sheet according to  claim 1 , wherein the one or more kinds of resin materials are selected from perfluoroalkoxy alkanes, cyclic olefin polymers, and syndiotactic polystyrene. 
     
     
         13 . The resin sheet according to  claim 1 , wherein the one or more kinds of resin materials is a norbornene-based polymer containing at least one of repeating units represented by the following formula (1): 
       
         
           
           
               
               
           
         
         wherein 
         X represents O, —CH 2 — or —CH 2 —CH 2 —; 
         each of substituents R 1 , R 2 , R 3 , and R 4  represents a group containing a group selected from hydrogen, a linear or branched organic group, or a derivative in which a part of these linear or branched organic groups is substituted with a halogen or a nitrile group; 
         m is an integer of 10 to 10000; and 
         n 1  is an integer of 0 to 5. 
       
     
     
         14 . The resin sheet according to  claim 1 , wherein the resin sheet contains 100 parts by weight of the one or more kinds of resin materials and 10 parts by weight to 70 parts by weight of the liquid crystal polymer. 
     
     
         15 . The resin sheet according to  claim 1 , wherein the resin sheet contains 100 parts by weight of the one or more kinds of resin materials and 15 parts by weight to 50 parts by weight of the liquid crystal polymer. 
     
     
         16 . The resin sheet according to  claim 1 , wherein the resin sheet contains 100 parts by weight of the one or more kinds of resin materials and 20 parts by weight to 40 parts by weight of the liquid crystal polymer. 
     
     
         17 . The resin sheet according to  claim 1 , wherein the liquid crystal polymer is a thermotropic liquid crystal polymer. 
     
     
         18 . A resin multilayer substrate comprising a laminate having a stacked plurality of the resin sheets according to  claim 1 . 
     
     
         19 . The resin multilayer substrate according to  claim 18 , wherein the resin multilayer substrate includes a bent portion.