Process of forming an electronic device including a plurality of singulated die

Abstract

An electronic device can include a first die having a first terminal at a first front side, and a second die having a second terminal at a second front side and a through via. In one aspect, a process of forming the electronic device includes supplying a second substrate including a die location of the second die. The process can also include attaching the second substrate to a handling substrate and singulating the second die from the second substrate before removing the handling substrate. In another aspect, the handling substrate can include a rigid substrate. The process can include orienting the front side of the first die and a back side of the second substrate front-to-back with respect to each other. In yet another aspect, the first terminal is electrically connected to the through via and the second terminal. In one embodiment, the electronic device can include a third die.

1 . An electronic device including a die stack comprising:
 a first die including:
 a first substrate having a first front side surface and a first back side surface separated by a first thickness; and 
 a first transistor lying at the first front side, the first transistor including a first terminal lying at the first front side; and 
   a second die including:
 a second substrate having a second front side surface and a second back side surface separated by a second thickness, wherein:
 the second thickness is less than approximately one half of the first thickness; and 
 the second thickness is less than approximately 90 microns; 
 
 a second transistor lying at the second front side; 
 a first through via; and 
 a second terminal lying at the second front side, and electrically connected to the first terminal, wherein the first terminal is electrically connected to the first through via. 
   
     
     
         2 . The electronic device of  claim 1 , wherein the second back side is closer to the first front side than the first back side. 
     
     
         3 . The electronic device of  claim 1 , further comprising a third die, the third die including:
 a third substrate having a third thickness less than approximately one half of the first thickness; and   a third transistor lying at a third front side.   
     
     
         4 . The electronic device of  claim 3 , wherein the second thickness is different from the third thickness. 
     
     
         5 . The electronic device of  claim 4 , wherein the third die further comprises:
 a second through via; and   a third terminal lying at the third front side, and electrically connected to the first terminal, wherein the first terminal is electrically connected to the second through via.   
     
     
         6 . The electronic device of  claim 5  further comprising a void disposed between the first and second electrical connections along the first front side surface and the second back side surface. 
     
     
         7 . The electronic device of  claim 6 , wherein solder electrically connects the second terminal lying at the second front side to the first terminal. 
     
     
         8 . The electronic device of  claim 3 , wherein the third die further comprises:
 a second through via; and   a third terminal lying at the third front side, and electrically connected to the first terminal, wherein the first terminal is electrically connected to the second through via.   
     
     
         9 . The electronic device of  claim 8  further comprising a void disposed between the first and second electrical connections along the first front side surface and the second back side surface. 
     
     
         10 . The electronic device of  claim 9 , wherein solder electrically connects the second terminal lying at the second front side to the first terminal. 
     
     
         11 . An electronic device including a die stack comprising:
 a first electrical connection comprising solder between a first terminal at a first front side surface of a first die and a second terminal at a first back side surface of a second die; and   a second electrical connection comprising solder between a third terminal at the first front side surface of the first die and a fourth terminal at the first back side surface of the second die, a void disposed between the first and second electrical connections along the first front side surface and the first back side surface.   
     
     
         12 . The device of  claim 11  further comprising a first transistor formed at a second front side of the second die, the first transistor including a fifth terminal, a third electrical connection comprising a through via at the second die, the third electrically connection electrically connecting the fifth terminal to the fourth terminal. 
     
     
         13 . The electronic device of  claim 12  further comprising a void disposed between the first and second electrical connections along the first front side surface and the second back side surface. 
     
     
         14 . The electronic device of  claim 11  further comprising a void disposed between the first and second electrical connections along the first front side surface and the second back side surface. 
     
     
         15 . The electronic device of  claim 11  wherein the first die has a first thickness and the second die has a second thickness, the second thickness less than approximately one half of the first thickness. 
     
     
         16 . An electronic device including a die stack comprising:
 a first solder connection connecting a first terminal at a first front side surface of a first die and a second terminal at a first back side surface of a second die; and   a second solder connection connecting a third terminal at the first front side surface of the first die and a fourth terminal at the first back side surface of the second die, a void disposed between the first and second solder connections along the first front side surface and the first back side surface.   
     
     
         17 . The device of  claim 16  further comprising a first transistor formed at a second front side of the second die, the first transistor including a fifth terminal, a third electrical connection comprising a through via at the second die, the third electrically connection electrically connecting the fifth terminal to the fourth terminal. 
     
     
         18 . The electronic device of  claim 17  further comprising a void disposed between the first and second electrical connections along the first front side surface and the second back side surface. 
     
     
         19 . The electronic device of  claim 16  further comprising a void disposed between the first and second electrical connections along the first front side surface and the second back side surface. 
     
     
         20 . The electronic device of  claim 16  wherein the first die has a first thickness and the second die has a second thickness, the second thickness less than approximately one half of the first thickness.