Semiconductor device packaging methods and structures thereof

1. A method of packaging semiconductor devices, the method comprising:

coupling a plurality of second dies to a top surface of a first die;

determining a distance between a second die of the plurality of second dies and the first die;

determining an amount of underfill material to dispose between the first die and the of second die based on the determined distance, using the following equation:

Shrinkage Volume( SV )=([ A×B×H ×(1− D )]+{[ C 2 −(π× C 2 )/4]×2( A+B )})× E;

wherein A is a width of the second die, B is a length of the second die, C is a desired width of a fillet of the underfill material proximate a perimeter of the second die, D is a bump density of the second die, E is a shrinkage rate of the underfill material, and H is the distance determined between the second die and the first die; and

disposing the determined amount of the underfill material under the second die.

2. The method according to claim 1 , wherein determining the distance between the second die and the first die comprises measuring a distance between a top surface of the second die and a top surface of the first die, and subtracting a thickness of the second die.

3. The method according to claim 1 , wherein disposing the determined amount of the underfill material comprises dispensing the underfill material along one side or two or more sides of the second die.

4. The method according to claim 3 , wherein dispensing the underfill material comprises using a dispensing needle.

5. The method according to claim 1 , wherein the first die comprises a three dimensional integrated circuit (3DIC) interposer or an interposer that includes a substrate with a plurality of through substrate vias (TSVs) formed therein.

6. The method according to claim 1 , wherein the first die includes a redistribution layer (RDL) proximate the top surface of the first die, wherein a plurality of bumps is disposed over portions of the RDL of the first die, and wherein coupling the plurality of second dies to the top surface of the first die comprises attaching the plurality of second dies to the plurality of bumps of the first die.

7. The method according to claim 1 , wherein the plurality of second dies further comprises a third die, wherein a width of a gap between the second die and the third die is smaller than the desired width of the fillet of the underfill material, and further comprising:

adjusting a total amount of the underfill material to dispose between the first die and the plurality of second dies based on the width of the gap.

8. The method according to claim 7 , wherein the total amount of the underfill material before the adjustment comprises a first volume of fillet disposed along the gap, and wherein the adjusting the total amount of the underfill material comprises:

calculating a second volume of the underfill material in the gap;

subtracting the first volume from the total amount of the underfill material; and

adding the second volume to the total amount of the underfill material.

9. A method of determining an amount of underfill material to dispose between a first die and a plurality of second dies of a three dimensional integrated circuit (3DIC), the first die being coupled to the plurality of second dies, the method comprising:

calculating a volume (V) of the underfill material for a second die of the plurality of second dies using the following equation:

V=V 1+ V 2;

wherein V1=[A×B×H×(1−D)] is a calculated volume of the underfill material under the second die, wherein V2={[C 2 −(π×C 2 )/4]×2(A+B)} is a calculated volume of a fillet of the underfill material proximate a perimeter of the second die, and wherein A is a width of the second die, B is a length of the second die, C is a desired width of the fillet, D is a bump density of the second die, and H is a distance between the second die and the first die.

10. The method according to claim 9 , wherein the calculating the volume (V) of the underfill material for the second die further comprises:

determining a shrinkage rate of the underfill material; and

calculating a shrinkage volume based on the shrinkage rate.

11. The method according to claim 10 , wherein calculating the shrinkage volume (SV) further comprises using the following equation:

SV=V×E;

wherein V is the calculated volume using equations in claim 9 , and wherein E is the shrinkage rate of the underfill material.

12. The method according to claim 9 , wherein a gap between at least two of the plurality of second dies is less than the desired width of the fillet of the underfill material, and wherein the calculating the volume (V) further comprises:

calculating a volume of the underfill material in the gap between the at least two of the plurality of second dies using the following equation:

VG=Z×A×X×N;

wherein Z is a die-to-die dimension between the at least two of the plurality of second dies, A is a width of a side of each of the plurality of second dies, X is a stand-off height of each of the plurality of second dies, and N is the number of gaps between the at least two of the plurality of second dies; and

calculating a total volume of the underfill material between the first die and the plurality of second dies based on the volume VG and the volume V calculated using the equation in claim 9 .

13. The method according to claim 12 , wherein the calculating the total volume of the underfill material comprises:

adding the volume VG with a plurality of volumes V for all of the plurality of second dies to calculate the total volume, wherein each of the plurality of volumes V is calculated using equations in claim 8 ; and

modifying the calculated total volume by subtracting from the calculated total volume a portion of the volume V2 corresponding to a volume of fillet disposed along the gap.

14. A method of packaging semiconductor devices, the method comprising:

coupling a plurality of second dies to a top surface of a first die using a plurality of electrical connectors between the respective second dies and the top surface of the first die;

determining a distance between at least one of the plurality of second dies and the first die;

determining an amount of underfill material (V) to dispose between the first die and the plurality of second dies based on the determined distance and a desired width of a fillet of the underfill material using the following equation:

V =( V 1+ V 2+ VG )× E;

wherein V1 comprises a volume of the underfill material under the plurality of second dies, V2 comprises a volume of the fillet proximate perimeters of the plurality of second dies, VG comprises a volume of the underfill material in one or more gaps between the plurality of second dies, and E is a shrinkage factor of the underfill material; and

disposing the determined amount of the underfill material under the plurality of second dies.

15. The method of claim 14 , wherein the determined amount of the underfill material is further based upon a calculation of volume occupied by the plurality of electrical connectors between the respective second dies and the top surface of the first die.

16. The method of claim 14 , wherein the distance between at least one of the plurality of second dies and the first die is a stand-off height, and wherein the stand-off height is equal to a thickness of one of the plurality of electrical connector.

17. The method of claim 14 , further comprising curing the underfill material.

18. The method of claim 14 , wherein VG is zero when one or more widths of the one or more gaps is larger than the desired width of the fillet.

19. The method of claim 14 , wherein VG is a non-zero volume of the underfill material in the one or more gaps when a width of the one or more gaps is smaller than the desired width of the fillet.

20. The method of claim 19 , wherein when VG is no-zero, V2 is adjusted to exclude volumes of fillet disposed along the one or more gaps with the width smaller than the desired width of the fillet.