LOC semiconductor assembled with room temperature adhesive

Abstract

A semiconductor device assembly having a lead frame and a semiconductor die configured to be attached to each other is disclosed. An adhesive is applied at room temperature through a stencil to the lead frame. The semiconductor die is urged against the adhesive to effect the attachment between the semiconductor device and the lead frame. The adhesive preferably is from about 75 percent to about 95 percent isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent, respectively, of titanium oxide.

1 . In combination, adhesive and a semiconductor die, the adhesive used for attaching a portion of the semiconductor die to portion of a lead frame having a plurality of lead fingers thereon, at least one lead finger of said plurality of lead fingers having an attaching surface, the a semiconductor die having a surface having at least one bond pad thereon for connection to at least one lead finger of the plurality of lead fingers of the lead frame comprising: 
 a nonconductive substantially tacky compliant polymer adhesive to be applied at room temperature to at least one of the attaching surface of the at least one lead finger and a portion of the surface of the semiconductor die for connecting the at least one bond pad of the semiconductor die to the at least one lead finger of the plurality of lead fingers of the lead frame, the nonconductive polymer adhesive including a first material from a group of copolymers that includes isobutyl compounds and a second material that is from a group of metal oxides.    
     
     
         2 . The combination of  claim 1  wherein a first portion of said nonconductive polymer adhesive is isobutyl acetal diphenol copolymer.  
     
     
         3 . The combination of  claim 1  wherein said nonconductive polymer adhesive includes said first material from a group of copolymers that includes isobutyl acetal diphenol copolymer and said second material that is from said group of metal oxides that includes titanium dioxide.  
     
     
         4 . The combination of  claim 3  wherein said nonconductive polymer adhesive has from about 75 percent to about 95 percent by weight of said isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent by weight, respectively, of said titanium dioxide.  
     
     
         5 . The combination of an adhesive and a semiconductor die comprising: 
 a nonconductive substantially tacky compliant polymer adhesive to be applied at room temperature to at least one attaching surface of at least one lead finger and a portion of a surface of the semiconductor die for connecting at least one bond pad of the semiconductor die to at least one lead finger of a plurality of lead fingers of a lead frame, the nonconductive polymer adhesive including a first material from a group of copolymers that includes isobutyl compounds and a second material that is from a group of metal oxides.    
     
     
         6 . The combination of  claim 5 , wherein a first portion of said nonconductive polymer adhesive is isobutyl acetal diphenol copolymer.  
     
     
         7 . The combination of  claim 5 , wherein said nonconductive polymer adhesive includes said first material from said group of copolymers that includes isobutyl acetal diphenol copolymer and said second material that is from said group of metal oxides that includes titanium dioxide.  
     
     
         8 . The combination of  claim 7 , wherein said nonconductive polymer adhesive has from about 75 percent to about 95 percent by weight of said isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent by weight, respectively, of said titanium dioxide.  
     
     
         9 . A semiconductor device comprising: 
 a lead of a lead frame having at least one attaching surface thereon;    a semiconductor die having an active surface having at least one bond pad thereon for electrical connection to the lead of the lead frame; and    a nonconductive polymer adhesive which includes a first material from a group of copolymers that includes isobutyl acetal diphenol copolymer and a second material that is from a group of metal oxides that includes titanium dioxide, said nonconductive polymer adhesive being applied to one of said attaching surface of the lead and a portion of the active surface of said semiconductor die for compression therebetween to connect said semiconductor device to said lead of the lead frame.    
     
     
         10 . A device comprising: 
 a lead frame having an attaching surface thereon;    a semiconductor die having a bond pad on a surface thereof; and    an adhesive that includes from about 75 percent to about 95 percent of isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent, respectively, of titanium dioxide, said adhesive being applied to one of said attaching surface of said lead frame and the bond pad of said semiconductor die for compression therebetween to Electrically connect said at least one bond pad of said semiconductor die to said attaching surface of said lead frame.    
     
     
         11 . A device comprising: 
 a lead frame having a plurality of attaching surfaces thereon;    a semiconductor die having a surface having a plurality of bond pads thereon for connection to said lead frame; and    a nonconductive polymer adhesive which includes a first material from a group of copolymers that includes isobutyl acetal diphenol copolymer and a second material that is from a group of metal oxides that includes titanium dioxide, said nonconductive polymer adhesive being applied to one of said attaching surfaces of said lead frame and said surface of said semiconductor die for compression therebetween to connect said active surface of said semiconductor die to said attaching surfaces of said lead frame.    
     
     
         12 . An assembly comprising: 
 a lead frame having an attaching surface;    a semiconductor die having bond pads on a surface thereof for connection to said lead frame; and    an adhesive that includes from about 75 percent to about 95 percent of isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent, respectively, of titanium dioxide, said adhesive being applied to one of said attaching surface of said lead frame and said semiconductor die for compression therebetween to connect said surface of said semiconductor device to said attaching surface of said lead frame.    
     
     
         13 . An assembly of a semiconductor device and a lead frame having a plurality of lead fingers thereon, at least one lead finger of said plurality of lead fingers having an attaching surface and having a semiconductor die having a surface having at least one bond pad thereon for connection to said at least one lead finger of said plurality of lead fingers of said lead frame, the assembly comprising: 
 a polymer adhesive that is tacky and compliant at room temperature, said polymer adhesive applied to one of said attaching surface of said at least one lead finger of said plurality of lead fingers of said lead frame and a portion of said surface of said semiconductor die to electrically connect said at least one bond pad of said semiconductor die to said at least one lead finger of said plurality of lead fingers of said lead frame, said polymer adhesive including a first material from a group of copolymers including isobutyl compounds and a second material from a group including metal oxides.    
     
     
         14 . The assembly of  claim 13 , wherein a first portion of said polymer adhesive is isobutyl acetal diphenol copolymer.  
     
     
         15 . The assembly of  claim 13 , wherein said polymer adhesive includes said first material from a group of copolymers that includes isobutyl acetal diphenol copolymer and said second material that is from said group of metal oxides that includes titanium dioxide.  
     
     
         16 . The assembly of  claim 15 , wherein said polymer adhesive has from about 75 percent to about 95 percent by weight of said isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent by weight, respectively, of said titanium dioxide.  
     
     
         17 . An assembly of at least one semiconductor device and a lead frame having a plurality of lead fingers thereon, at least one lead finger of said plurality of lead fingers having an attaching surface and having a semiconductor die having a surface for connection to said at least one lead finger of said plurality of lead fingers of said lead frame, the assembly comprising: 
 an adhesive that is tacky and compliant at room temperature, said adhesive applied to one of said attaching surface of said at least one lead finger of said plurality of lead fingers of said lead frame and a portion of said surface of said semiconductor die to connect said semiconductor die to said at least one lead finger of said plurality of lead fingers of said lead frame, said adhesive including a first material from a group of copolymers including isobutyl compounds and a second material from a group including metal oxides.    
     
     
         18 . The assembly of  claim 17 , wherein a first portion of said adhesive is isobutyl acetal diphenol copolymer.  
     
     
         19 . The assembly of  claim 17 , wherein said adhesive includes said first material from a group of copolymers that includes isobutyl acetal diphenol copolymer and said second material that is from said group of metal oxides that includes titanium dioxide.  
     
     
         20 . The assembly of  claim 15 , wherein said adhesive has from about 75 percent to about 95 percent by weight of said isobutyl acetal diphenol copolymer and from about 25 percent to about 5 percent by weight, respectively, of said titanium dioxide