Polymer films and electronic devices

Abstract

In a first aspect, a polymer film includes a polyimide, wherein the polyimide includes two or more dianhydrides, including 15 to 35 mol % of a first monomer that is a crankshaft monomer and 15 to 35 mol % of a second monomer that is a flexible monomer, and two or more diamines, including 1 to 35 mol % of a third monomer that is a rotational inhibitor monomer and 15 to 49 mol % a fourth monomer that is a rigid rotational monomer, wherein the mol % of each monomer is based on the total of all four monomers. The polymer film has a dielectric dissipation loss factor, D f , of 0.005 or less, a water absorption of 2.0% or less and a water vapor transport rate of 50 (g×mil)/(m 2 ×day) or less.

What is claimed is: 
     
         1 . A polymer film comprising a polyimide, wherein the polyimide comprises:
 two or more dianhydrides comprising:
 15 to 35 mol % of a first monomer that is a crankshaft monomer; and 
 15 to 35 mol % of a second monomer that is a flexible monomer; and 
   two or more diamines comprising:
 1 to 35 mol % of a third monomer that is a rotational inhibitor monomer; and 
 15 to 49 mol % a fourth monomer that is a rigid rotational monomer, wherein the mol % of each monomer is based on the total of all four monomers, wherein the polymer film has:
 a dielectric dissipation loss factor, D f , of 0.005 or less; 
 a water absorption of 2.0% or less; and 
 a water vapor transport rate of 50 (g×mil)/(m 2  ×day) or less. 
 
   
     
     
         2 . The polymer film of  claim 1 , wherein the crankshaft dianhydride monomer is 3,3′,4,4′-biphenyl tetracarboxylic dianhydride or a functional derivative thereof. 
     
     
         3 . The polymer film of  claim 1 , wherein the flexible dianhydride monomer is 4,4′-oxydiphthalic anhydride. 
     
     
         4 . The polymer film of  claim 1 , wherein the rotational inhibitor diamine monomer is selected from the group consisting of of 2,2′-dimethyl-4,4′-diaminodiphenyl, 2,2′-bis(trifluoromethyl)benzidine and mixtures thereof. 
     
     
         5 . The polymer film of  claim 1 , wherein the rigid rotational diamine monomer is selected from the group consisting of p-phenylenediamine, 5-amino-2-(p-aminophenyl)benzoxazole and mixtures thereof. 
     
     
         6 . The polymer film of  claim 1 , further comprising a flexible diamine monomer. 
     
     
         7 . The polymer film of  claim 6 , wherein the flexible diamine monomer is selected from the group consisting of 4,4′-oxydianiline, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene and mixtures thereof. 
     
     
         8 . The polymer film of  claim 6 , wherein the flexible diamine monomer has a Kier flexibility in the range of from 7.0 to 14.0. 
     
     
         9 . The polymer film of  claim 1 , wherein the polymer film further comprises up to 20 wt % of a filler comprising an inorganic filler, an organic filler or a mixture thereof. 
     
     
         10 . The polymer film of  claim 9 , wherein the filler comprises a thermally conductive filler. 
     
     
         11 . The polymer film of  claim 1 , wherein the polymer film has a dielectric dissipation loss factor, D f , of 0.0035 or less. 
     
     
         12 . The polymer film of  claim 1 , wherein the polymer film has a water absorption of 1.25% or less. 
     
     
         13 . The polymer film of  claim 1 , wherein the polymer film has a water vapor transport rate of 15 (g×mil)/(m 2 ×day) or less. 
     
     
         14 . The polymer film of  claim 1 , wherein the polymer film has a thickness in the range of from 10 to 150 μm. 
     
     
         15 . A metal-clad laminate comprising the polymer film of  claim 1  and a first metal layer adhered to a first outer surface of the polymer film. 
     
     
         16 . The metal-clad laminate of  claim 15 , further comprising a second metal layer adhered to a second outer surface of the polymer film. 
     
     
         17 . An electronic device comprising the polymer film of  claim 1 .