Package on package devices and methods of packaging semiconductor dies

Abstract

Package on package (PoP) devices and methods of packaging semiconductor dies are disclosed. A PoP device includes a first packaged die and a second packaged die coupled to the first packaged die. Metal stud bumps are disposed between the first packaged die and the second packaged die. The metal stud bumps include a bump region and a tail region coupled to the bump region. The metal stud bumps are embedded in solder joints.

What is claimed is: 
     
       1. A package-on-package (PoP) device, comprising:
 a first packaged die comprising a first die; 
 a second packaged die comprising a second die coupled to the first packaged die; and 
 a plurality of metal stud bumps disposed between the first packaged die and the second packaged die, wherein the plurality of metal stud bumps is disposed laterally adjacent to the first die of the first packaged die, and wherein the plurality of metal stud bumps each include a bump region proximal the first package die and a tail region extending from the bump region towards the second packaged die, and wherein each of the plurality of metal stud bumps is embedded in a solder joint disposed between a surface of the tail region facing the first packaged die and the second packaged die die; and 
 a dielectric material located between one of the plurality of metal stud bumps and the first die, the dielectric material having a first height less than a second height of external connections located in physical contact with the first die, the external connections being located on an opposite side of the first die from the second die. 
 
     
     
       2. The device according to  claim 1 , wherein the first packaged die comprises the first die disposed over a first substrate, and wherein the second packaged die comprises the second die disposed over a second substrate. 
     
     
       3. The device according to  claim 2 , wherein the second packaged die comprises a plurality of second dies stacked vertically above the second substrate. 
     
     
       4. The device according to  claim 2 , wherein the plurality of metal stud bumps is coupled to the first substrate, and wherein each of the plurality of metal stud bumps comprises a height of about 50 to 300 μm and a diameter of about 50 to 200 μm proximate the first substrate. 
     
     
       5. The device according to  claim 2 , wherein the first substrate or the second substrate comprises a plurality of through substrate vias disposed therein. 
     
     
       6. The device according to  claim 1 , wherein the plurality of metal stud bumps comprises a material selected from the group consisting essentially of Cu, Al, Au, Pt, Pd, and combinations thereof. 
     
     
       7. A package-on-package (PoP) device, comprising:
 a bottom packaged die comprising a first die and a peripheral region surrounding the first die, the bottom packaged die further comprising a plurality of metal stud bumps disposed in the peripheral region on a top surface thereof, the plurality of metal stud bumps disposed next to the first die, each of the plurality of metal stud bumps including a bump region and a tail region coupled to the bump region, the tail region having a diameter smaller than the bump region region, wherein the bottom packaged die comprises a through substrate via, the through substrate via comprising a straight sidewall that extends from a first side of a substrate to a second side of the substrate; and 
 a top packaged die coupled to the bottom packaged die, the top packaged die comprising a plurality of contacts formed on a bottom surface thereof, wherein each of the plurality of metal stud bumps on the bottom packaged die is embedded in a solder joint coupled to one of the plurality of contacts on the top packaged die die and wherein the solder joint covers a first surface of a respective one of the metal stud bumps, the first surface extending from a top of the metal stud bump to a bottom of the metal stud bump, the solder joint being in physical contact with a first dielectric material of the bottom packaged die and a second dielectric material of the top packaged die. 
 
     
     
       8. The device according to  claim 7 , further comprising a plurality of solder balls disposed on a bottom surface of the bottom packaged die. 
     
     
       9. The device according to  claim 7 , wherein each of the plurality of metal stud bumps extends fully to one of the plurality of contacts on the top packaged die. 
     
     
       10. The device according to  claim 7 , wherein each of the plurality of metal stud bumps extends partially to one of the plurality of contacts on the top packaged die. 
     
     
       11. The device according to  claim 7 , wherein the bottom packaged die comprises a plurality of bond pads on the top surface thereof, and wherein each of the plurality of metal stud bumps is bonded to a bond pad on the top surface of the bottom packaged die. 
     
     
       12. The device according to  claim 11 , wherein one of the plurality of metal stud bumps is bonded to each of the plurality of bond pads on the bottom packaged die. 
     
     
       13. The device according to  claim 11 , wherein one of the plurality of metal stud bumps is bonded to some of the plurality of bond pads on the bottom packaged die. 
     
     
       14. The device according to  claim 13 , wherein one of the plurality of metal stud bumps is bonded to each of the plurality of bond pads in corner regions of the bottom packaged die. 
     
     
       15. The device according to  claim 14 , wherein one of the plurality of metal stud bumps is bonded to each of the plurality of bond pads in central edge regions of the bottom packaged die. 
     
     
       16. A method of packaging semiconductor dies, the method comprising:
 coupling a first die to a top surface of a first substrate to form a first packaged die die, wherein after the coupling solder balls located between the first substrate and the first die are both partially embedded within a dielectric material of the first substrate and also extend out of the dielectric material of the first substrate; 
 coupling a second die to a top surface of a second substrate to form a second packaged die; and 
 forming a plurality of metal stud bumps between the first packaged die and the second packaged die, wherein the plurality of metal stud bumps is coupled to the first packaged die at the top surface of the first substrate, the plurality of metal bumps disposed laterally adjacent to the first die, each of the plurality of metal stud bumps including a bump region proximal the first packaged die and a tail region coupled to the bump region, the tail region extending from the bump region towards the second packaged die, wherein each of the plurality of metal stud bumps is embedded in a solder joint disposed between the first packaged die and the second packaged die die, wherein the solder joint is formed on the second packaged die prior to the embedding and wherein the solder joint is in physical contact with the dielectric material of the first substrate. 
 
     
     
       17. The method according to  claim 16 , wherein coupling the first die to the top surface of the first substrate comprises coupling solder bumps on a bottom surface of the first die to bond pads or traces on the top surface of the first substrate. 
     
     
       18. The method according to  claim 16 , wherein coupling the second die to the top surface of the second substrate comprises wire-bonding contacts on a top surface of the second die to contact pads on the top surface of the second substrate, wherein the method further comprises coupling a third die over the second die and wire-bonding contacts on a top surface of the third die to the contact pads on the top surface of the second substrate, and wherein forming the molding compound further comprises forming the a molding compound over the third die. 
     
     
       19. The method according to  claim 16 , wherein forming the plurality of metal stud bumps between the first packaged die and the second packaged die comprises providing a wire, forming a ball at an end of the wire, placing the ball against a bond pad on the top surface of the first substrate, ultrasonically vibrating the ball against the bond pad, and heating the first substrate. 
     
     
       20. The method according to  claim 16 , further comprising: heating the first substrate and the second substrate to reflow a solder material to form the solder joint on the bottom surface of the second substrate. 
     
     
       21. A package-on-package (PoP) device, comprising:
 a first packaged die comprising a first die;   a second packaged die comprising a second die coupled to the first packaged die; and   a plurality of metal stud bumps disposed between the first packaged die and the second packaged die, wherein the plurality of metal stud bumps is disposed laterally adjacent to the first die of the first packaged die, and wherein the plurality of metal stud bumps each include a bump region proximal the first package die and a tail region extending from the bump region towards the second packaged die, and wherein each of the plurality of metal stud bumps is in contact with a solder joint disposed between the first packaged die and the second packaged die, the solder joint in physical contact with a first dielectric material of the first packaged die and a second dielectric material of the second packaged die.    
     
     
       22. The device according to claim 21, wherein the first packaged die comprises the first die disposed over a first substrate, and wherein the second packaged die comprises the second die disposed over a second substrate.  
     
     
       23. The device according to claim 22, wherein the second packaged die comprises a plurality of second dies stacked vertically above the second substrate.  
     
     
       24. The device according to claim 22, wherein the plurality of metal stud bumps is coupled to the first substrate, and wherein each of the plurality of metal stud bumps comprises a height of about 50 to 300 μm and a diameter of about 50 to 200 μm proximate the first substrate.  
     
     
       25. The device according to claim 22, wherein the first substrate or the second substrate comprises a plurality of through substrate vias disposed therein.  
     
     
       26. The device according to claim 21, wherein the plurality of metal stud bumps comprises a material selected from the group consisting essentially of Cu, Al, Au, Pt, Pd, and combinations thereof.  
     
     
       27. A package-on-package (PoP) device, comprising:
 a bottom packaged die comprising a first die and a peripheral region surrounding the first die, the bottom packaged die further comprising a plurality of metal stud bumps disposed in the peripheral region on a top surface thereof, the plurality of metal stud bumps disposed next to the first die, each of the plurality of metal stud bumps including a bump region and a tail region coupled to the bump region, the tail region having a diameter smaller than the bump region; and   a top packaged die coupled to the bottom packaged die, the top packaged die comprising a plurality of contacts formed on a bottom surface thereof, wherein each of the plurality of metal stud bumps on the bottom packaged die is in contact with a solder joint coupled to one of the plurality of contacts on the top packaged die, wherein at least one of the plurality of contacts is connected to a through substrate via which extends with straight sidewalls through a substrate of the top packaged die, wherein the solder joint fully covers a sidewall of at least one of the plurality of metal stud bumps facing the first die and is in physical contact with dielectric portions of both the bottom packaged die and the top packaged die.    
     
     
       28. The device according to claim 27, further comprising a plurality of solder balls disposed on a bottom surface of the bottom packaged die.  
     
     
       29. The device according to claim 27, wherein each of the plurality of metal stud bumps extends fully to one of the plurality of contacts on the top packaged die.  
     
     
       30. The device according to claim 27, wherein each of the plurality of metal stud bumps extends partially to one of the plurality of contacts on the top packaged die.  
     
     
       31. The device according to claim 27, wherein the bottom packaged die comprises a plurality of bond pads on the top surface thereof, and wherein each of the plurality of metal stud bumps is bonded to a bond pad on the top surface of the bottom packaged die.  
     
     
       32. The device according to claim 31, wherein one of the plurality of metal stud bumps is bonded to each of the plurality of bond pads on the bottom packaged die.  
     
     
       33. The device according to claim 31, wherein one of the plurality of metal stud bumps is bonded to some of the plurality of bond pads on the bottom packaged die.  
     
     
       34. The device according to claim 33, wherein one of the plurality of metal stud bumps is bonded to each of the plurality of bond pads in corner regions of the bottom packaged die.  
     
     
       35. The device according to claim 34, wherein one of the plurality of metal stud bumps is bonded to each of the plurality of bond pads in central edge regions of the bottom packaged die.  
     
     
       36. A method of packaging semiconductor dies, the method comprising:
 coupling a first die to a top surface of a first substrate to form a first packaged die;   coupling a second die to a top surface of a second substrate to form a second packaged die;   forming a plurality of metal stud bumps between the first packaged die and the second packaged die, wherein the plurality of metal stud bumps is coupled to the first packaged die at the top surface of the first substrate, the plurality of metal bumps disposed laterally adjacent to the first die, each of the plurality of metal stud bumps including a bump region proximal the first packaged die and a tail region coupled to the bump region, the tail region extending from the bump region towards the second packaged die;   forming a solder material on the second package die; and   bonding the solder material to the plurality of metal bumps after the forming the solder material, wherein after the bonding each of the plurality of metal stud bumps is in contact with a solder joint disposed between the first packaged die and the second packaged die, the solder joint in physical contact with a dielectric material of the first substrate, external connections located between the first die and the first substrate extending towards the second die further than the dielectric material.    
     
     
       37. The method according to claim 36, wherein coupling the first die to the top surface of the first substrate comprises coupling solder bumps on a bottom surface of the first die to bond pads or traces on the top surface of the first substrate.  
     
     
       38. The method according to claim 36, wherein coupling the second die to the top surface of the second substrate comprises wire-bonding contacts on a top surface of the second die to contact pads on the top surface of the second substrate, wherein the method further comprises coupling a third die over the second die and wire-bonding contacts on a top surface of the third die to the contact pads on the top surface of the second substrate, and forming a molding compound over the third die.  
     
     
       39. The method according to claim 36, wherein forming the plurality of metal stud bumps between the first packaged die and the second packaged die comprises providing a wire, forming a ball at an end of the wire, placing the ball against a bond pad on the top surface of the first substrate, ultrasonically vibrating the ball against the bond pad, and heating the first substrate.  
     
     
       40. The method according to claim 36, further comprising heating the first substrate and the second substrate to reflow a solder material to form the solder joint on the bottom surface of the second substrate.