Die-up ball grid array package with attached stiffener ring
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 substrate that has an electrically insulating layer and a plurality of electrically conductive features formed on a first surface of said insulating layer and an array of contact pads formed on a second surface of said insulating layer;
a substantially planar stiffener that has a first surface and a second surface, wherein said second surface of said planar stiffener is attached to said first surface of said insulating layer;
a plurality of solder balls attached to said contact pads of said insulating layer;
a ring shaped stiffener defined by opposing first and second surfaces, wherein said ring shaped stiffener has a central opening that is open at said first and said second surfaces of said ring shaped stiffener, wherein said ring shaped stiffener is attached to said first surface of said substantially planar stiffener to surround a central region of said first surface of said substantially planar stiffener; and
an integrated circuit (IC) die mounted in said central region of said first surface of said substantially planar stiffener,
wherein said ring shaped stiffener has an outer surface between said first and said second surfaces of said ring shaped stiffener that is flush with an outer profile of said planar stiffener,
wherein a thermal path is formed between said IC die and said ring shaped stiffener via said substantially planar stiffener, whereby heat is conducted over said thermal path from said IC die to said ring shaped stiffener during operation of said integrated circuit die.
2. The package of claim 1 , wherein said substrate is a tape substrate.
3. The package of claim 1 , wherein said substrate is an organic substrate.
4. The package of claim 1 , wherein said ring shaped stiffener includes at least one metal.
5. The package of claim 4 , wherein said at least one metal includes copper.
6. The package of claim 4 , wherein said at least one metal includes aluminum.
7. The package of claim 1 , further comprising an encapsulate material applied within a cavity defined by said first surface of said substantially planar stiffener and said opening of said ring shaped stiffener to encapsulate said IC die.
8. The package of claim 7 , wherein said encapsulating material is a resin, mold compound, or an epoxy.
9. The package of claim 1 , wherein said ring shaped stiffener and said planar stiffener are made from substantially the same material.
10. The package of claim 1 , wherein said ring shaped stiffener and said planar stiffener have substantially the same thermal expansion coefficient.
11. The package of claim 1 , further comprising:
a thermally conductive adhesive layer that mounts said IC die to said central region.
12. The package of claim 1 , further comprising:
a thermally conductive adhesive layer that mounts said ring shaped stiffener to said first surface of said planar stiffener.
13. The package of claim 1 , wherein said substantially planar stiffener includes a plurality of openings that are open at said first surface and said second surface.
14. The package of claim 13 , wherein said ring shaped stiffener is attached to said first surface of said substantially planar substrate without substantially covering any of said plurality of openings in said planar stiffener.