Bonding material and bonding method employing same

Abstract

The present invention aims at providing a bonding material having both preferable dispensing properties and preferable bonding properties, and also providing a bonding method employing the bonding material. Provided are: a bonding material comprising fine silver particles having an average primary particle diameter of smaller than or equal to 130 nm, and a crosslinking-type inter-particle distance keeping agent crosslinking between the fine silver particles and keeping a distance between the fine silver particles; and a bonding method employing the bonding material.

1 . A bonding material comprising
 fine silver particles having an average primary particle diameter of smaller than or equal to 130 nm, and   a crosslinking-type inter-particle distance keeping agent crosslinking between the fine silver particles and keeping a distance between the fine silver particles.   
     
     
         2 . The bonding material according to  claim 1 , wherein
 the crosslinking-type inter-particle distance keeping agent is a compound α expressed by formula (I) below   
       
         
           
           
               
               
           
         
         (here, in formula (I), R represents an organic group having a valence of 2 to 4, 
         A and B represent a hydroxyl group, amino group, carboxyl group, or thiol group, and in a case where two As are present, the two As may be identical or different from each other and in a case where two Bs are present, the two Bs may be identical or different from each other, and 
         assuming that in the longest straight-chain moiety forming R, the longest moiety from among moieties between an atom 1 bonding to A and an atom 2 bonding to B is a first main chain, the number of chain-forming atoms of the first main chain is 10 to 180). 
       
     
     
         3 . The bonding material according to  claim 2 , wherein
 at least one from among A and B in the formula (I) is a hydroxyl group, amino group, or thiol group, and   the longest straight-chain moiety forming R in the formula (I) has a side chain, and the number of chain-forming atoms of the longest straight-chain moiety in the side chain is smaller than or equal to ⅓ of the number of chain-forming atoms of the first main chain.   
     
     
         4 . The bonding material according to  claim 2 , wherein the longest straight-chain moiety forming R in the formula (I) has a side chain, the side chain is a hydrocarbon group having a carbon number of 1 to 12, and A and B may bond to the side chain. 
     
     
         5 . The bonding material according to  claim 2 , wherein
 assuming that in the formula (I), the longest straight-chain moiety forming the compound α is a second main chain, chain-forming atoms (excluding atoms at a chain terminal) of the first main chain and the second main chain form a group selected from —CH 2 —, —CH(R a )—, —C(R a ) 2 —, —CX 2 —, —CX(R a )—, —CH═, —C(R a )═, ═C═, —CO—, —NH—, —N(R′)—, —N═, —N(OH)—, —O—, —S—, and —SO 2 —   (here, R a  represents a side chain of the longest straight-chain moiety forming R, and X represents halogen).   
     
     
         6 . The bonding material according to  claim 2 , wherein the compound α is any one of formulae (II) to (IV) below 
       
         
           
           
               
               
           
         
         (here, in formula (II), v and y are each independently an integer of 1 to 2, w is an integer of 0 to 10, and x is an integer of 14 to 40) 
       
       
         
           
           
               
               
           
         
         (here, in formula (III), the plurality of ks are each independently an integer of 3 to 10, the plurality of is are each independently an integer of 6 to 16, and m is an integer of 2 to 8)
   [Chemical formula 4] 
   C n H 2n+1 CH(OH)—(CH 2 ) p —CONH—(CH 2 ) q —NHCO—(CH 2 ) r —CH(OH)C s H 2s+1   (IV)
 
 
         (here, in formula (IV), n and s are each independently an integer of 3 to 10, p and r are each independently an integer of 6 to 18, and q is an integer of 2 to 10). 
       
     
     
         7 . The bonding material according to  claim 1 , wherein
 the bonding material further comprises silver particles having an average primary particle diameter of 0.3 to 10 μm.   
     
     
         8 . The bonding material according to  claim 1 , wherein
 the fine silver particles are coated with an organic compound.   
     
     
         9 . The bonding material according to  claim 1 , wherein
 the bonding material further comprises a polar solvent.   
     
     
         10 . The bonding material according to  claim 1 , wherein
 the bonding material further comprises an acid-type dispersing agent.   
     
     
         11 . A bonding method comprising:
 placing the bonding material according to  claim 1  between substances to be bonded and heating the bonding material to form a bonding layer from the bonding material; and bonding together the substances accordingly.