Acidic electrolytic copper plating liquid, method for forming preform layer, method for producing joining sheet, method for producing joining substrate, and method for producing joined body

Abstract

This acidic electrolytic copper plating solution contains a soluble copper salt, an azole compound which has 2 or 3 nitrogen atoms in a five-membered ring and serves as a copper ion electrodeposition inhibitor, an acid, and water, in which a copper concentration is 0.1 mol/L or more, an azole compound concentration is 10 mmol/L or more and 50 mmol/L or less, and a chloride ion concentration is 10 ppm or less.

What is claimed is: 
     
         1 . An acidic electrolytic copper plating solution comprising:
 a soluble copper salt;   an azole compound which has 2 or more and 3 or less nitrogen atoms in a five-membered ring represented by Formulae (1) to (4) and serves as a copper ion electrodeposition inhibitor;   an acid; and   water,   wherein a copper concentration is 0.1 mol/L or more, an azole compound concentration is 10 mmol/L or more and 50 mmol/L or less, and a chloride ion concentration is 10 ppm or less,   
       
         
           
           
               
               
           
         
         in Formulae (1) to (4), R 1  to R 4  may be the same as or different from each other, and are any one of an alkyl group having 10 or less carbon atoms, an alkenyl group having 10 or less carbon atoms, an alkynyl group having 10 or less carbon atoms, an aryl group having 10 or less carbon atoms, an aralkyl group having 10 or less carbon atoms, or an alkoxy group having 10 or less carbon atoms, or a group in which a hydrogen atom of these groups is substituted with any one of a halogen atom, a hydroxyl group, a carboxyl group, an amino group, an alkyl-substituted amino group having 5 or less carbon atoms, a hydroxyalkyl-substituted amino group having 5 or less carbon atoms in an alkyl chain, or a mercapto group, or any one of an amino group, an alkyl-substituted amino group having 5 or less carbon atoms, a hydroxyalkyl-substituted amino group having 5 or less carbon atoms in an alkyl chain, a mercapto group, a hydroxyl group, a carboxyl group, a halogen atom, or a hydrogen atom. 
       
     
     
         2 . A method for forming a preform layer, the method comprising:
 a step of placing a copper sheet or a substrate on a cathode side in the acidic electrolytic copper plating solution according to claim  1  and performing acidic electrolytic copper plating to form a porous preform layer on one surface or both surfaces of the copper sheet or the substrate, wherein the porous preform layer serves as a copper plating film, contains copper particles, and has an average porosity of 11% to 78%,   wherein the surface of the copper particle is coated with copper nanoparticles with a particle size smaller than an average grain size of the copper particles,   wherein an average grain size calculated using a BET value of the copper nanoparticles is 9.59 nm or more and 850 nm or less, and   wherein the average porosity of the preform layer is an arithmetic average of a porosity (P) determined by Equation (A) based on a total area (S 1 ) of the preform layer and an area (S 2 ) of a void portion in the preform layer, which is calculated by image analysis of a cross-section of the preform layer using an electron scanning microscope,
     P  (%)=( S   2   /S   1 )×100  (A).
 
   
     
     
         3 . A method for producing a bonding sheet, the method comprising:
 a step of forming a porous preform layer on one surface or both surfaces of a copper sheet by the method for forming a preform layer according to claim  2 .   
     
     
         4 . A method for producing a bonded body, the method comprising:
 a step of laminating a base material, an electronic component, and the bonding sheet produced by the method for producing a bonding sheet according to claim  3  so that the bonding sheet is disposed between the base material and the electronic component; and   a step of heating the base material and the electronic component under pressure in a laminating direction to produce a bonded body.   
     
     
         5 . A method for producing a bonding substrate, the method comprising:
 a step of forming a porous preform layer on one surface of a substrate by the method for forming a preform layer according to claim  2 .   
     
     
         6 . A method for producing a bonded body, the method comprising:
 a step of laminating the bonding substrate produced by the method for producing a bonding substrate according to claim  5  and an electronic component so that the porous preform layer is disposed between the bonding substrate and the electronic component; and   a step of heating the bonding substrate and the electronic component under pressure in a laminating direction to produce a bonded body.