Heat-curable resin composition for semiconductor encapsulation

Abstract

Provided is a versatile heat-curable resin composition for semiconductor encapsulation that has a favorable water resistance and abradability, and exhibits a superior fluidity and a small degree of warpage even when used to perform encapsulation on a large-size wafer. The heat-curable resin composition of the invention contains: (A) a cyanate ester compound having not less than two cyanato groups in one molecule; (B) a phenol curing agent containing a resorcinol-type phenolic resin; (C) a curing accelerator; and (D) a spherical inorganic filler.

What is claimed: 
     
         1 . A heat-curable resin composition for semiconductor encapsulation, comprising:
 (A) a cyanate ester compound having not less than two cyanato groups in one molecule, said cyanate ester compound containing a cyanate ester compound (A-1) represented by the following formula (1) and exhibiting a viscosity of not higher than 50 Pa·s when measured by a B-type rotary viscometer at 23° C. in accordance with a method described in JIS K7117-1:1999   
       
         
           
           
               
               
           
         
         wherein n represents an integer of 0 or 1; each of R 1  and R 2  represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; and R 3  represents a divalent linking group selected from the groups expressed by the following formulae (2) to (5) 
       
       
         
           
           
               
               
           
         
         (B) a phenol curing agent containing a resorcinol-type phenolic resin represented by the following formula (6) 
       
       
         
           
           
               
               
           
         
         wherein n represents an integer of 0 to 10; each of R 1  and R 2  independently represents a hydrogen atom or a monovalent group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an allyl group and a vinyl group; 
         (C) a curing accelerator; and 
         (D) an inorganic filler that is spherical, has an average particle diameter of 1 to 20 μm when measured by a laser diffraction method, has been surface-treated with a silane coupling agent represented by the following formula (7) and is added in an amount of 1,200 to 2,200 parts by mass with respect to 100 parts by mass of a sum total of said components (A) and (B)
   R 1   a (OR 2 ) (3-a) Si—C 3 H 6 —R 3   (7)
 
 
       
       wherein a represents an integer of 0 to 3; R 1  represents a methyl group or an ethyl group; R 2  represents an alkyl group having 1 to 3 carbon-atoms; and R 3  represents a group selected from the group consisting of the nitrogen-containing functional groups represented by the following formulae (8) to (11). 
       
         
           
           
               
               
           
         
       
     
     
         2 . The heat-curable resin composition for semiconductor encapsulation according to  claim 1 , wherein said component (A) contains two or more kinds of cyanate ester compounds including at least one kind of said cyanate ester compound (A-1), and said cyanate ester compound (A-1) is in an amount of not smaller than 90% by mass, but smaller than 100% by mass with respect to a whole amount of said component (A) added. 
     
     
         3 . The heat-curable resin composition for semiconductor encapsulation according to  claim 1 , wherein said resorcinol-type phenolic resin represented by the following formula (6) is in an amount of 10 to 100% by mass with respect to a whole amount of said component (B) added, and cyanato groups in said cyanate ester compound as said component (A) are in an amount of 0.5 to 100 equivalents with respect to 1 equivalent of hydroxyl group in said phenol curing agent as said component (B). 
     
     
         4 . The heat-curable resin composition for semiconductor encapsulation according to  claim 2 , wherein said resorcinol-type phenolic resin represented by the following formula (6) is in an amount of 10 to 100% by mass with respect to a whole amount of said component (B) added, and cyanato groups in said cyanate ester compound as said component (A) are in an amount of 0.5 to 100 equivalents with respect to 1 equivalent of hydroxyl group in said phenol curing agent as said component (B). 
     
     
         5 . The heat-curable resin composition for semiconductor encapsulation according to  claim 1 , wherein a linear expansion coefficient thereof is in a range of 3.0 to 5.0 ppm/° C. as a result of measuring a specimen of a size of 5×5×15 mm at an increasing rate of 5° C./min from 25 to 300° C. while constantly applying a pressure of 19.6 mN, in accordance with a method described in JIS K 7197:2012. 
     
     
         6 . A production method of a resin-encapsulated semiconductor device, comprising:
 a step of collectively encapsulating an entire silicon wafer or entire substrate with at least one semiconductor element mounted thereon by a cured product of the heat-curable resin composition for semiconductor encapsulation as set forth in  claim 1 , wherein   said silicon wafer or substrate has an area of 200 to 1,500 cm 2 , and   said silicon wafer or substrate exhibits an amount of warpage of not larger than 2 mm after encapsulation.   
     
     
         7 . A production method of a resin-encapsulated semiconductor device, comprising:
 a step of collectively encapsulating an entire silicon wafer or entire substrate with at least one semiconductor element mounted thereon by a cured product of the heat-curable resin composition for semiconductor encapsulation as set forth in  claim 2 , wherein   said silicon wafer or substrate has an area of 200 to 1,500 cm 2 , and   said silicon wafer or substrate exhibits an amount of warpage of not larger than 2 mm after encapsulation.   
     
     
         8 . A production method of a resin-encapsulated semiconductor device, comprising:
 a step of collectively encapsulating an entire silicon wafer or entire substrate with at least one semiconductor element mounted thereon by a cured product of the heat-curable resin composition for semiconductor encapsulation as set forth in  claim 3 , wherein   said silicon wafer or substrate has an area of 200 to 1,500 cm 2 , and   said silicon wafer or substrate exhibits an amount of warpage of not larger than 2 mm after encapsulation.   
     
     
         9 . A production method of a resin-encapsulated semiconductor device, comprising:
 a step of collectively encapsulating an entire silicon wafer or entire substrate with at least one semiconductor element mounted thereon by a cured product of the heat-curable resin composition for semiconductor encapsulation as set forth in  claim 4 , wherein   said silicon wafer or substrate has an area of 200 to 1,500 cm 2 , and   said silicon wafer or substrate exhibits an amount of warpage of not larger than 2 mm after encapsulation.   
     
     
         10 . The production method of the resin-encapsulated semiconductor device according to  claim 6 , wherein in the step of said collective encapsulation, the semiconductor element is encapsulated by covering the semiconductor element with said heat-curable resin composition under a pressed condition or under a depressed condition in vacuum, and then heating and curing said heat-curable resin composition. 
     
     
         11 . The production method of the resin-encapsulated semiconductor device according to  claim 7 , wherein in the step of said collective encapsulation, the semiconductor element is encapsulated by covering the semiconductor element with said heat-curable resin composition under a pressed condition or under a depressed condition in vacuum, and then heating and curing said heat-curable resin composition. 
     
     
         12 . The production method of the resin-encapsulated semiconductor device according to  claim 8 , wherein in the step of said collective encapsulation, the semiconductor element is encapsulated by covering the semiconductor element with said heat-curable resin composition under a pressed condition or under a depressed condition in vacuum, and then heating and curing said heat-curable resin composition. 
     
     
         13 . The production method of the resin-encapsulated semiconductor device according to  claim 9 , wherein in the step of said collective encapsulation, the semiconductor element is encapsulated by covering the semiconductor element with said heat-curable resin composition under a pressed condition or under a depressed condition in vacuum, and then heating and curing said heat-curable resin composition.