Chip package with grease heat sink

Abstract

The present invention relates to enhanced protection of the active surface and the bond wires or ball array of a microelectronic device, and to thermal management of the microelectronic device as it is packaged with a printed circuit board (PCB) or other substrate. The enhanced protection and thermal management are accomplished with a high-temperature thermal grease that is glob topped or encapsulated over the bond wires or ball array, and the active surface of the microelectronic device. The high-temperature thermal grease exchanges heat, particularly by conduction, away from the active surface of the microelectronic device as well as away from the bond wires.

1 . An integrated circuit (IC) chip package, comprising: 
 a substrate with an IC chip mounted thereon, wherein the substrate comprises a metallic heat sink and the IC chip has an active surface;    a grease in contact with the active surface of the IC chip; and    a container disposed upon the substrate, wherein the grease is enclosed within the container and the substrate, and wherein the container is in contact with the active surface of the IC chip.    
     
     
         2 . The IC chip package of  claim 1 , further comprising an electrical connector extending from the active surface, wherein the electrical connector is in electrical communication with the IC chip, and wherein the electrical connector comprises a bond wire between the active surface and a printed circuit board disposed upon the heat sink.  
     
     
         3 . The IC chip package of  claim 1 , wherein: 
 the container comprises a metal; and    the container contacts a printed circuit board disposed upon the substrate.    
     
     
         4 . The IC chip package of  claim 1 , further comprising a flip chip disposed over the active surface of the IC chip.  
     
     
         5 . The IC chip package of  claim 4 , further comprising: 
 an electrical connector extending from the active surface, wherein: 
 the electrical connector is in electrical communication with the IC chip;  
 the electrical connector comprises a bond wire;  
 the bond wire is in contact with the grease;  
 the container comprises a metal; and  
 the container is disposed over the IC chip and the flip chip.  
   
     
     
         6 . The IC chip package of  claim 1 , further comprising: 
 an electrical connector extending from the active surface, wherein: 
 the electrical connector is in electrical communication with the IC chip; and  
 the container and the substrate together enclose the grease, the electrical connector, and the IC chip.  
   
     
     
         7 . The IC chip package of  claim 1 , wherein the grease has a grease thermal conductivity, the container has a container thermal conductivity, and the grease thermal conductivity is less than the container thermal conductivity.  
     
     
         8 . The IC chip package of  claim 1 , further comprising a vent hole in the container.  
     
     
         9 . The IC chip package of  claim 1 , wherein the grease has a thermal conductivity in a range from about 2 Watts/m·K to about 5 Watts/m·K.  
     
     
         10 . The IC chip package of  claim 1 , wherein the grease has a dielectric constant in a range from about 1.2 to about 10.  
     
     
         11 . The IC chip package of  claim 1 , wherein the grease has a melting point in a range from about 190° C. to about 220° C.  
     
     
         12 . The IC chip package of  claim 1 , wherein the grease has a weight loss at about 100° C. after 30 days of less than about 0.15%.  
     
     
         13 . An integrated circuit (IC) chip package with IC chip elements having an IC chip with an active surface, the active surface having extending therefrom an electrical connector in electrical communication with the IC chip, the IC chip being mounted upon a substrate, the IC chip package comprising: 
 a grease in contact with the active surface of the IC chip; and    a container disposed upon the substrate and enclosing a volume external to the IC chip elements, the grease enclosed within the container and the substrate, wherein the grease fills the volume enclosed by the container and the container comprises a metal.    
     
     
         14 . The IC chip package of  claim 13 , wherein the container has a container thermal conductivity and the grease has a grease thermal conductivity that is less than the container thermal conductivity.  
     
     
         15 . The IC chip package of  claim 13 , further comprising: 
 a vent hole in the container.    
     
     
         16 . The IC chip package of  claim 13 , wherein the grease contacts the container.  
     
     
         17 . The IC chip package of  claim 13 , wherein the substrate comprises a metallic heat sink.  
     
     
         18 . The IC chip package of  claim 17 , wherein the electrical connector comprises a bond wire between the active surface and a printed circuit board disposed upon the heat sink.  
     
     
         19 . The IC chip package of  claim 13 , further comprising: 
 a flip chip disposed over the active surface of the IC chip.    
     
     
         20 . The IC chip package of  claim 13 , wherein the container and the substrate together enclose the grease, the electrical connector, and the IC chip.  
     
     
         21 . An IC chip package having an IC chip with an active surface, the active surface having an electrical connector extending therefrom in electrical communication with the IC chip, the IC chip being mounted upon a board-on-chip (BOC) substrate having a first side and an opposite second side, the IC chip package comprising: 
 a grease in contact with the active surface of the IC chip; and    a container disposed upon the BOC substrate, the grease enclosed within the container and the substrate, wherein: 
 the IC chip is mounted on the first side of the BOC substrate;  
 the IC chip package further comprises a second IC chip; and  
 the second IC chip is disposed over the first side of the BOC substrate.  
   
     
     
         22 . The IC chip package of  claim 21 , wherein: 
 the IC chip package further comprises a third IC chip, wherein the third IC chip is disposed over the first side of the BOC substrate and over the second IC chip.    
     
     
         23 . An IC chip package having an IC chip with an active surface, the active surface having an electrical connector extending therefrom in electrical communication with the IC chip, the IC chip being mounted upon a board-on-chip (BOC) substrate having a first side and an opposite second side, the IC chip package comprising: 
 a grease in contact with the active surface of the IC chip; and    a container disposed upon the BOC substrate, wherein the grease is enclosed within the container and the substrate, wherein: 
 the IC chip is mounted on the first side of the BOC substrate;  
 the IC chip package further comprises a second IC chip; and  
 the second IC chip is disposed over the second side of the BOC substrate.  
   
     
     
         24 . The IC chip package of  claim 23 , wherein: 
 the IC chip package further comprises a third IC chip, wherein the third IC chip is disposed over the second side of the BOC substrate and over the second IC chip.    
     
     
         25 . An IC chip package with IC elements having an IC chip with an active surface, the active surface having extending therefrom an electrical connector in electrical communication with the IC chip, the IC chip being mounted upon a substrate, the IC chip package comprising: 
 a grease in contact with the active surface of the IC chip; and    a container comprising a metal and having a thermal conductivity that is greater than a thermal conductivity of the grease, the container disposed upon the substrate and in contact with both the grease and the substrate, the container enclosing a volume external to the IC elements, wherein: 
 the grease is enclosed within the container and the substrate, and the grease fills the volume enclosed by the container; and  
 the container and the substrate enclose the active surface of the IC chip.  
   
     
     
         26 . The IC chip package of  claim 25 , wherein the grease has: 
 a thermal conductivity in a range from about 2 Watts/m·K to about 5 Watts/m·K;    a dielectric constant in a range from about 1.2 to about 10; and    a melting point in a range from about 190° C. to about 220° C.