Adhesive composition, process for producing the same, adhesive film using the same, substrate for mounting semiconductor and semiconductor device

Abstract

The present invention provides an adhesive composition which comprises (a) an epoxy resin, (b) a curing agent and (c) a polymer compound incompatible with said epoxy resin, and further optionally comprises (d) a filler and/or (e) a curing accelerator; a process for producing an adhesive composition, comprising: mixing (a) the epoxy resin and (b) the curing agent with (d) the filler, followed by mixing the resultant mixture with (c) the polymer compound incompatible with the epoxy resin; an adhesive film comprising the above-mentioned adhesive composition formed into a film; a substrate for mounting semiconductor comprising a wiring board and the above-mentioned adhesive film disposed thereon on its side where chips are to be mounted; and a semiconductor device which comprises the above-mentioned adhesive film or the substrate for mounting semiconductor.

1 . An adhesive film which has been formed from an adhesive composition into a film state, the adhesive film being formed from the adhesive composition alone or formed by providing an adhesive composition layer on one surface or both surfaces of a substrate, 
 wherein the adhesive composition comprises    (a) an epoxy resin;    (b) a curing agent; and    (c) a polymer compound incompatible with said epoxy resin, and    satisfies at least one of the following requirements (i) to (iii):    (i) the components of the adhesive composition are separated into two phases after being cured as viewed in the cross-section thereof;    (ii) the adhesive composition gives a cured product having a storage elastic modulus at 240° C. of 1 to 20 MPa; and    (iii) the adhesive composition has pores having an average diameter of 0.01 μm to 2 μm after being cured and a volume percentage of the pores is 0.1 to 20% by volume.    
   
   
       2 . The adhesive film according to  claim 1 , wherein a ratio of A:B is 0.24:1 to 1:1, where A represents a total weight of (a) the epoxy resin and (b) the curing agent and B represents a weight of (c) the polymer compound incompatible with the epoxy resin.  
   
   
       3 . The adhesive film according to  claim 1 , wherein (a) the epoxy resin is a solid epoxy resin having a softening point of 50° C. or more as measured by a ring and ball method.  
   
   
       4 . The adhesive film according to  claim 1 , wherein (a) the epoxy resin has no mutagen.  
   
   
       5 . The adhesive film according to  claim 1 , wherein (b) the curing agent is a phenolic resin having a hydroxyl equivalent of 150 g/eq or more.  
   
   
       6 . The adhesive film according to  claim 1 , wherein (b) the curing agent is a phenolic resin represented by the following general formula (I):  
     
       
         
         
             
             
         
       
       wherein R 1  each may be the same or different from each other and represents a hydrogen atom, a straight or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group, an aralkyl group, an alkenyl group, a hydroxyl group, an aryl group, or a halogen atom; n represents an integer of 1 to 3; and m represents an integer of 0 to 50.  
     
   
   
       7 . The adhesive film according to  claim 6 , wherein the phenolic resin represented by general formula (I) has a water absorption of 2% by volume or less.  
   
   
       8 . The adhesive film according to  claim 1 , wherein (c) the polymer compound incompatible with the epoxy resin is a functional group-containing acrylic copolymer.  
   
   
       9 . The adhesive film according to  claim 8 , wherein the functional group-containing acrylic copolymer is an epoxy group-containing acrylic copolymer.  
   
   
       10 . The adhesive film according to  claim 9 , wherein the epoxy group-containing acrylic copolymer contains 0.5 to 6% by weight of glycidyl acrylate or glycidyl methacrylate as a starting material therefor.  
   
   
       11 . The adhesive film according to  claim 8 , wherein the functional group-containing acrylic copolymer has a weight average molecular weight of 100,000 or more.  
   
   
       12 . The adhesive film according to  claim 8 , wherein the functional group-containing acrylic copolymer has a glass transition temperature of −50° C. to 30° C.  
   
   
       13 . The adhesive film according to  claim 1 , wherein (c) the polymer compound is an epoxy group-containing acrylic copolymer with a weight average molecular weight of 100,000 or more which contains 1.5 to 2.5% by weight of glycidyl acrylate or glycidyl methacrylate, wherein the adhesive composition contains 1 to 50 parts by volume of (d) an inorganic filler with an average particle diameter of 0.010 μm to 0.1 μm based on 100 parts by volume of the resin.  
   
   
       14 . The adhesive film according to  claim 1 , wherein the adhesive composition further comprises (e) a curing accelerator.  
   
   
       15 . The adhesive film according to  claim 14 , wherein (e) the curing accelerator is an imidazole compound.  
   
   
       16 . The adhesive film according to  claim 1 , wherein the two phases comprise a sea phase and an islands phase, wherein, a length of an outer periphery of the islands phase represented by S and an area of a cross-section represented by V satisfy a relationship represented by the following formula (1):  
         S/√{square root over (V)}> 3.6   (1).  
   
   
       17 . The adhesive film according to  claim 1 , wherein the adhesive composition comprises: 
 49.5 to 17.0% by weight of the sum of (a) the epoxy resin and (b) the curing agent;    50.0 to 70.0% by weight of (c) the polymer compound;    0.45 to 10.0% by weight of (d) a filler; and    0.05 to 3.0% by weight of (e) a curing accelerator.    
   
   
       18 . The adhesive film according to  claim 17 , wherein a ratio of (a) the epoxy resin to (b) the curing agent is 33:67 to 75:25.