3-D semiconductor die structure with containing feature and method
View Patent ↗A die-on-die assembly has a first die ( 10 ) and a second die ( 50 ). The first die ( 10 ) has a first contact extension ( 28,42 ) and a peg ( 32,44,45 ) extending a first height above the first die. The second die ( 50 ) has a second contact extension ( 68 ) connected to the first contact extension and has a containing feature ( 62 ) extending a second height above the second die surrounding the peg. The peg extends past the containing feature. Because the peg extends past the containing feature, lateral movement between the first and second die can cause the peg to come in contact with and be constrained by the containing feature. The peg and containing feature are thus useful in constraining movement between the first and second die.
1. A die-on-die assembly, comprising:
a first die having a first contact extension and having a peg extending a first height above the first die, wherein the peg is displaced on the surface of the die from the first contact extension; and
a second die having a second contact extension connected to the first contact extension and having a containing feature extending a second height above the second die surrounding the peg, wherein
the peg extends past the containing feature, and
the containing feature comprises a plurality of features extending to the second height, each of the plurality of features being spaced apart from adjacent ones of the plurality of features by a distance sufficient to enable ingress and egress of a die attachment adhesive material, but the distance being insufficient for the peg to pass between adjacent features.
2. The die-on-die assembly of claim 1 , wherein the peg comprises a first metal adjacent to the first die and a second metal on an end of the peg away from the first die.
3. The die-on-die assembly of claim 2 , wherein the second metal comprises tin.
4. The die-on-die assembly of claim 3 , wherein the first height is greater than the second height.
5. The die-on-die assembly of claim 4 , wherein an area of the first metal at an interface with the second metal is less than 144 square microns.
6. The die-on-die assembly of claim 2 , wherein the first height is greater than the second height.
7. The die-on-die assembly of claim 2 , wherein an area of the first metal at an interface with the second metal is less than 144 square microns.
8. The die-on-die assembly of claim 2 , wherein a sum of the first height and the second height exceeds a sum of a height of the first contact extension and a height of the second contact extension.
9. The die-on-die assembly of claim 2 , wherein the containing feature comprises a plurality of elements extending from the second die defining an area of constrained movement, wherein the peg is within the area of constrained movement.
10. The die-on-die assembly of claim 2 , wherein the containing feature is for restricting movement of the second die in relation to the first die so that the first contact extension is aligned to the second contact extension within a predetermined tolerance.
11. The die-on-die assembly of claim 2 , wherein:
the first die is further characterized as having a second peg displaced from both the first contact extension and the peg; and
the second die is further characterized as having a second containing area extending the second height above the second die surrounding the second peg.
12. The die-on-die assembly of claim 1 , wherein a sum of the first height and the second height exceeds a sum of a height of the first contact extension and a height of the second contact extension.
13. The die-on-die assembly of claim 12 , wherein the containing feature comprises a plurality of elements extending from the second die defining an area of constrained movement, wherein the peg is within the area of constrained movement.
14. The die-on-die assembly of claim 12 , wherein the containing feature is for restricting movement of the second die in relation to the first die so that the first contact extension is aligned to the second contact extension within a predetermined tolerance.
15. The die-on-die assembly of claim 12 , wherein:
the first die is further characterized as having a second peg displaced from both the first contact extension and the peg; and
the second die is further characterized as having a second containing area extending the second height above the second die surrounding the second peg.
16. The die-on-die assembly of claim 1 , wherein the containing feature comprises a plurality of elements extending from the second die defining an area of constrained movement, wherein the peg is within the area of constrained movement.
17. The die-on-die assembly of claim 16 , wherein:
the first die is further characterized as having a second peg displaced from both the first contact extension and the peg; and
the second die is further characterized as having a second containing area extending the second height above the second die surrounding the second peg.
18. The die-on-die assembly of claim 1 , wherein the containing feature is for restricting movement of the second die in relation to the first die so that the first contact extension is aligned to the second contact extension within a predetermined tolerance.
19. The die-on-die assembly of claim 1 , wherein:
the first die is further characterized as having a second peg displaced from both the first contact extension and the peg; and
the second die is further characterized as having a second containing area extending the second height above the second die surrounding the second peg.
20. The die-on-die assembly of claim 1 , wherein the first height is greater than the second height.