Integrated circuit package employing flip-chip technology and method of assembly

Abstract

An integrated circuit package includes a package substrate having a first surface including a first array of interconnection sites and a second array of interconnection sites. A first integrated circuit die has a first surface including an array of interconnection sites. A second integrated circuit die has a first surface including an array of interconnection sites. The first array of interconnection sites is electrically connected to the array of interconnection sites of the second integrated circuit die. The second array of interconnection sites is electrically connected to the array of interconnection sites of the first integrated circuit die. The first integrated circuit die is positioned amid the package substrate and the second integrated circuit die.

What is claimed is:  
     
         1 . An integrated circuit package comprising: 
 a package substrate having a first surface including a first array of interconnection sites, and a second array of interconnection sites;    a first integrated circuit die having a first surface including an array of interconnection sites electrically connected to the second array of interconnection sites of the package substrate; and    a second integrated circuit die having a first surface including an array of interconnection sites electrically connected to the first array of interconnection sites of the package substrate, wherein the first integrated circuit die is positioned amid the package substrate and the second integrated circuit die.    
     
     
         2 . The integrated circuit package of  claim 1  wherein the package substrate defines a recessed area sized to accommodate the first integrated circuit die, the recessed area including the second array of interconnection sites.  
     
     
         3 . The integrated circuit package of  claim 1  wherein the first array of interconnection sites of the package substrate is electrically connected to the array of interconnection sites of the second integrated circuit die by reflowed solder.  
     
     
         4 . The integrated circuit package of  claim 1  wherein the second array of interconnection sites of the package substrate is electrically connected to the array of interconnection sites of the first integrated circuit die by reflowed solder.  
     
     
         5 . The integrated circuit package of  claim 1  wherein gaps between the second integrated circuit die and the package substrate at the first array of interconnection sites of the package substrate and the array of interconnection sites of the second integrated circuit die are underfilled with epoxy.  
     
     
         6 . The integrated circuit package of  claim 5  wherein gaps between the first integrated circuit die and the package substrate at the array of interconnection sites of the first integrated circuit die and the second array of interconnection sites of the package substrate are underfilled with epoxy.  
     
     
         7 . The integrated circuit package of  claim 1  wherein the first integrated circuit die has a second surface opposite the first surface, with the second surface of the first integrated circuit die having an additional array of interconnection sites, wherein the first surface of the second integrated circuit die includes a further array of interconnection sites that is different than the array of interconnection sites of the first surface of the second integrated circuit die, and wherein the further array of interconnection sites of the second integrated circuit die is electrically connected to the additional array of interconnection sites on the second surface of the first integrated circuit die.  
     
     
         8 . The integrated circuit package of  claim 7  wherein the first array of interconnection sites of the package substrate is electrically connected to the array of interconnection sites on the first surface of the second integrated circuit die by reflowed solder, wherein the second array of interconnection sites of the package substrate is electrically connected to the array of interconnection sites on the first surface of the first integrated circuit die by reflowed solder, and wherein the further array of interconnection sites of the second integrated circuit die is electrically connected to the additional array of interconnection sites on the second surface of the first integrated circuit die by reflowed solder.  
     
     
         9 . The integrated circuit package of  claim 7  wherein the package substrate defines a recessed area sized to accommodate the first integrated circuit die, the recessed area including the second array of interconnection sites.  
     
     
         10 . The integrated circuit package of  claim 1  wherein the first surface of the package substrate includes an auxiliary array of interconnection sites that is different than the first and second arrays of interconnection sites of the package substrate.  
     
     
         11 . The integrated circuit package of  claim 1  wherein the first integrated circuit die is a memory die.  
     
     
         12 . The integrated circuit package of  claim 1  wherein the second integrated circuit die is a processor die.  
     
     
         13 . A method of assembling an integrated circuit package comprising: 
 providing a package substrate having a first surface including a first array of interconnection sites and a second array of interconnection sites;    engaging a first integrated circuit die with the package substrate such that an array of interconnection sites on a first surface of the first integrated circuit die are substantially aligned with the second array of interconnection sites of the package substrate;    engaging a second integrated circuit die with the package substrate such that an array of interconnection sites on a first surface of the second integrated circuit die are substantially aligned with the first array of interconnection sites of the package substrate, with the first integrated circuit die positioned amid the package substrate and the second integrated circuit die; and    simultaneously electrically connecting the first array of interconnection sites to the array of interconnection sites of the second integrated circuit die, and the second array of interconnection sites to the array of interconnection sites of the first integrated circuit die.    
     
     
         14 . The method of  claim 13  wherein the package substrate defines a recessed area that includes the second array of interconnection sites, and wherein the step of engaging the first integrated circuit die with the package substrate includes: 
 positioning the first integrated circuit die within the recessed area of the package substrate.  
 
     
     
         15 . The method of  claim 13  wherein the step of simultaneously electrically connecting the first array of interconnection sites to the array of interconnection sites of the second integrated circuit die, and the second array of interconnection sites to the array of interconnection sites of the first integrated circuit die includes: 
 simultaneously reflowing solder between the first array of interconnection sites and the array of interconnection sites of the second integrated circuit die, and between the second array of interconnection sites and the array of interconnection sites of the first integrated circuit die.  
 
     
     
         16 . The method of  claim 13  wherein the step of engaging the second integrated circuit die with the package substrate includes: 
 aligning a further array of interconnection sites on the first surface of the second integrated circuit die that is different than the array of interconnection sites on the first surface of the second integrated circuit die with an additional array of interconnection sites on a second surface of the first integrated circuit die that is opposite the first surface of the first integrated circuit die.  
 
     
     
         17 . The method of  claim 16  wherein the package substrate defines a recessed area that includes the second array of interconnection sites, and wherein the step of engaging the second integrated circuit die with the package substrate further includes: 
 positioning the first integrated circuit die within the recessed area of the package substrate such that the additional array of interconnection sites on the second surface of the first integrated circuit die is substantially aligned with the further array of interconnection sites of the second integrated circuit die.  
 
     
     
         18 . The method of  claim 16  wherein the step of simultaneously electrically connecting the second array of interconnection sites to the array of interconnection sites of the first integrated circuit die, and the first array of interconnection sites to the array of interconnection sites of the second integrated circuit die includes: 
 simultaneously electrically connecting the further array of interconnection sites of the second integrated circuit die to the additional array of interconnection sites on the second surface of the first integrated circuit die.  
 
     
     
         19 . The method of  claim 18  wherein the step of simultaneously electrically connecting the second array of interconnection sites to the array of interconnection sites of the first integrated circuit die, the first array of interconnection sites to the array of interconnection sites of the second integrated circuit die, and the further array of interconnection sites of the integrated circuit die to the additional array of interconnection sites on the second surface of the first integrated circuit die includes: 
 simultaneously reflowing solder between the second array of interconnection sites and the array of interconnection sites of the first integrated circuit die, between the first array of interconnection sites and the array of interconnection sites of the second integrated circuit die, and between the further array of interconnection sites of the second integrated circuit die and the additional array of interconnection sites on the second surface of the first integrated circuit die.  
 
     
     
         20 . A method of assembling an integrated circuit package comprising: 
 providing a package substrate having a first surface including a first array of interconnection sites and a second array of interconnection sites;    engaging a first integrated circuit die with the package substrate such that an array of interconnection sites on a first surface of the first integrated circuit die are substantially aligned with the second array of interconnection sites of the package substrate;    electrically connecting the second array of interconnection sites to the array of interconnection sites of the first integrated circuit die;    engaging a second integrated circuit die with the package substrate such that an array of interconnection sites on a first surface of the second integrated circuit die are substantially aligned with the first array of interconnection sites of the package substrate, with the first integrated circuit die positioned amid the package substrate and the second integrated circuit die; and    electrically connecting the first array of interconnection sites to the array of interconnection sites of the second integrated circuit die.    
     
     
         21 . The method of  claim 20  wherein the step of electrically connecting the second array of interconnection sites to the array of interconnection sites of the first integrated circuit die includes: 
 reflowing solder between the second array of interconnection sites and the array of interconnection sites of the first integrated circuit die.  
 
     
     
         22 . The method of  claim 21  wherein the step of electrically connecting the first array of interconnection sites to the array of interconnection sites of the package substrate includes: 
 reflowing solder between the first array of interconnection sites and the array of interconnection sites of the package substrate.  
 
     
     
         23 . The method of  claim 20  wherein the step of engaging the second integrated circuit die with the package substrate includes: 
 engaging a further array of interconnection sites on the first surface of the second integrated circuit die that is different than the array of interconnection sites on the first surface of the second integrated circuit die with an additional array of interconnection sites on a second surface of the first integrated circuit die that is opposite the first surface of the first integrated circuit die.  
 
     
     
         24 . The method of  claim 23 , and further including: 
 electrically connecting the further array of interconnection sites of the second integrated circuit die to the additional array of interconnection sites on the second surface of the first integrated circuit die.    
     
     
         25 . The method of  claim 24  wherein the step of electrically connecting the further array of interconnection sites of the second integrated circuit die to the additional array of interconnection sites on the second surface of the first integrated circuit die includes: 
 reflowing solder between the further array of interconnection sites of the second integrated circuit die and the additional array of interconnection sites on the second surface of the first integrated circuit die.