Die-up ball grid array package with die-attached heat spreader
An electrically and thermally enhanced die-up tape substrate ball grid array (BGA) package and die-up plastic substrate BGA package are described. A substrate that has a first surface and a second surface is provided. The stiffener has a first surface and a second surface. The second stiffener surface is attached to the first substrate surface. An IC die has a first surface and a second surface. The first IC die surface is mounted to the first stiffener surface. A plurality of solder balls is attached to the second substrate surface. In one aspect, a heat spreader is mounted to the second IC die surface. In another aspect, the stiffener is coupled to ground to act as a ground plane. In another aspect, the substrate has a window opening that exposes a portion of the second stiffener surface. The exposed portion of the second stiffener surface is configured to be coupled to a printed circuit board (PCB). In another aspect, a metal ring is attached to the first stiffener surface. In another aspect, wire bond openings in the stiffener are bridged by one or more studs.
1. A ball grid array (BGA) package, comprising:
a metal stiffener that functions as a first heat spreader;
a substantially planar substrate having a plurality of contact pads formed in a conductive layer at a first surface electrically connected through said substrate to a plurality of solder ball pads on a second surface of said substrate, wherein said first surface of said substrate is attached to a second surface of said stiffener; and
a metal second heat spreader that has a first surface; and
an IC die coupled between a first surface of said stiffener and said first surface of said second heat spreader to create a substantially symmetrical structure, wherein said second heat spreader and said stiffener combine to reduce deformation of said stiffener.
2. The package of claim 1 , further comprising:
an encapsulating material that encapsulates said IC die and at least a portion of said second heat spreader on said first surface of said stiffener.
3. The package of claim 2 , wherein a surface of said second heat spreader is not encapsulated by said encapsulating material and is accessible.
4. The package of claim 2 , wherein said second heat spreader is entirely encapsulated by said encapsulating material.
5. The package of claim 2 , wherein said encapsulating material is a resin, a molding compound, or an epoxy.
6. The package of claim 1 , wherein said stiffener comprises copper.
7. The package of claim 1 , wherein said stiffener comprises aluminum.
8. The package of claim 1 , wherein said second heat spreader is substantially planar.
9. The package of claim 1 , wherein said substrate is a tape substrate.
10. The package of claim 1 , wherein said substrate is an organic substrate.
11. The package of claim 1 , wherein said second heat spreader comprises copper.
12. The package of claim 1 , wherein said second heat spreader comprises aluminum.
13. The package of claim 1 , wherein an area of a surface of said second heat spreader that is mounted to said second surface of said IC die is less than an area of said second surface of said IC die.
14. The package of claim 1 , wherein said second heat spreader and said stiffener are made from substantially the same material.
15. The package of claim 1 , wherein said second heat spreader and said stiffener have substantially the same thermal expansion coefficient.
16. The package of claim 1 , further comprising:
a thermally conductive adhesive layer that mounts said first surface of said IC die to said first surface of said stiffener.
17. The package of claim 1 , further comprising:
a thermally conductive adhesive layer that mounts said second heat spreader to said second surface of said IC die.
18. A ball grid array (BGA) package, comprising:
a substrate that has a first surface and a second surface;
a metal stiffener that has a first surface and a second surface, wherein said second surface of said stiffener is attached to said first surface of said substrate;
a metal heat spreader that has a first surface;
an IC die coupled between said first surface of said stiffener and said first surface of said heat spreader, wherein said stiffener and said heat spreader have substantially the same thermal expansion coefficient, wherein said heat spreader reduces deformation of said stiffener due to thermal stress imposed by said IC die on said stiffener; and
a plurality of solder balls attached to said second surface of said substrate.
19. The package of claim 18 , wherein said heat spreader is configured to dissipate heat generated by said IC die.
20. The package of claim 18 , wherein said IC die is mounted to said first surface of said stiffener with an epoxy.
21. The package of claim 20 , wherein said epoxy is a silver filled epoxy.
22. The package of claim 20 , wherein a surface of said IC die is coupled to said first surface of said heat spreader, and wherein an area of said surface of said IC die is greater than an area of said first surface of said heat spreader.
23. The package of claim 18 , further comprising:
an exposed first surface of the BGA package, wherein said heat spreader has a second surface that forms a portion of said exposed first surface of the BGA package.
24. The package of claim 18 , wherein said heat spreader is internal to the BGA package.
25. The package of claim 18 , wherein said substrate is a tape substrate.
26. The package of claim 18 , wherein said plurality of solder balls is located outside an outer dimensional profile of said IC die.
27. The package of claim 18 , wherein said substrate is an organic substrate.
28. The package of claim 18 , further comprising:
an encapsulating material that encapsulates said IC die and at least a portion of said heat spreader on said first surface of said substrate.
29. The package of claim 28 , wherein a surface of said heat spreader is not encapsulated by said encapsulating material and is accessible.
30. The package of claim 28 , wherein said heat spreader is entirely encapsulated by said encapsulating material on said IC die.
31. The package of claim 28 , wherein said encapsulating material is one of a resin, a molding compound, or an epoxy.
32. The package of claim 18 , wherein said heat spreader comprises copper.
33. The package of claim 18 , wherein said heat spreader comprises aluminum.
34. The package of claim 18 , wherein said heat spreader is substantially planar.