Ball grid array package with patterned stiffener layer

1. A stiffener for stiffening a substrate in a ball grid array (BGA) package, comprising:

a substantially planar first surface having a centrally located cavity;

a substantially planar second surface opposed to said first surface, wherein said second surface has a centrally located protruding portion that opposes said centrally located cavity; and

at least one recessed portion in at least one edge of said first and said second surfaces, wherein said at least one edge has a first corner at a first end and a second corner at a second end, wherein said at least one recessed portion is located between said first and second corners of said at least one edge wherein the second surface is capable of attachment to the substrate such that said protruding portion extends through a centrally located window opening that is open at first and second surfaces of the substrate, and

wherein said first surface of said stiffener in said cavity is capable of mounting an integrated circuit die.

2. The stiffener of claim 1 , wherein said cavity is substantially rectangular shaped, having a first edge, a second edge, a third edge, and a fourth edge.

3. The stiffener of claim 2 , wherein at least one recessed portion includes:

a first substantially rectangular shaped recessed portion in a first edge of said first and said second surfaces;

a second substantially rectangular shaped recessed portion in a second edge of said first and said second surfaces;

a third substantially rectangular shaped recessed portion in a third edge of said first and said second surfaces; and

a fourth substantially rectangular shaped recessed portion in a fourth edge of said first and said second surfaces.

4. The stiffener of claim 2 , wherein at least one recessed portion includes:

a first substantially trapezoidal shaped recessed portion in a first edge of said first and said second surfaces;

a second substantially trapezoidal shaped recessed portion in a second edge of said first and said second surfaces;

a third substantially trapezoidal shaped recessed portion in a third edge of said first and said second surfaces; and

a fourth substantially trapezoidal shaped recessed portion in a fourth edge of said first and said second surfaces.

5. The stiffener of claim 2 , wherein at least one recessed portion includes:

a first irregular shaped recessed portion in a first edge of said first and said second surfaces;

a second irregular shaped recessed portion in a second edge of said first and said second surfaces;

a third irregular shaped recessed portion in a third edge of said first and said second surfaces; and

a fourth irregular shaped recessed portion in a fourth edge of said first and said second surfaces.

6. The stiffener of claim 2 , wherein said at least one recessed portion includes a first recessed portion that is substantially rectangular shaped and has an edge that coincides with said first edge of said cavity.

7. The stiffener of claim 2 , wherein said at least one recessed portion includes a first recessed portion that is substantially trapezoidal shaped and has an edge that coincides with said first edge of said cavity.

8. The stiffener of claim 2 , wherein said at least one recessed portion includes a first recessed portion that is irregular shaped and has an edge that coincides with said first edge of said cavity.

9. The stiffener of claim 1 , wherein said at least one recessed portion includes a first recessed portion that has at least one notch formed in at least one edge of said first recessed portion.

10. The stiffener of claim 1 , wherein said protruding portion has a height such that said protruding portion is capable of extending through an opening in a BGA package substrate when the stiffener is present in a BGA package, such that a surface of said protruding portion is capable of being attached to a surface of a printed circuit board (PCB) when the BGA package is mounted to the PCB.

11. The stiffener of claim 1 , wherein said protruding portion has a height such that said protruding portion is capable of extending through an opening in a BGA package substrate when the stiffener is present in a BGA package, such that a surface of said protruding portion is capable of extending into a cavity formed in a surface of a printed circuit board (PCB) when the BGA package is mounted to the PCB.

12. The stiffener of claim 1 , wherein the stiffener is a heat spreader.

13. The stiffener of claim 1 , wherein the stiffener comprises at least one metal.

14. The stiffener of claim 13 , wherein said at least one metal includes copper.

15. The stiffener of claim 13 , wherein said at least one metal includes aluminum.

16. The stiffener of claim 1 , wherein the stiffener comprises a ceramic.

17. The stiffener of claim 1 , wherein the stiffener comprises a thermally conductive dielectric material.

18. The stiffener of claim 1 , wherein the stiffener comprises an organic material.

19. The stiffener of claim 1 , wherein the stiffener comprises a plastic.

20. The stiffener of claim 1 , wherein the stiffener is electrically conductive.

21. A ball grid array (BGA) package, comprising:

a stiffener that has

a substantially planar first surface having a centrally located cavity,

a substantially planar second surface opposed to said first surface of said stiffener, wherein said second surface of said stiffener has a centrally located protruding portion that opposes said centrally located cavity, and

at least one recessed portion in an edge of said first and said second surfaces of said stiffener, wherein said at least one edge has a first corner at a first end and a second corner at a second end, wherein said at least one recessed portion is located between said first and second corners of said at least one edge;

a substantially planar substrate that has

a plurality of contact pads on a first surface of said substrate that are electrically connected through said substrate to a plurality of solder ball pads on a second surface of said substrate, and

a centrally located window opening that is open at said first and second surfaces of said substrate, wherein said substrate is attached to said second surface of said stiffener such that said protruding portion extends through said window opening; and

an IC die mounted to said first surface of said stiffener in said cavity.

22. The package of claim 21 , wherein said cavity is substantially rectangular shaped, having a first edge, a second edge, a third edge, and a fourth edge.

23. The package of claim 22 , wherein at least one recessed portion includes:

a first substantially rectangular shaped recessed portion in a first edge of said first and said second surfaces of said stiffener;

a second substantially rectangular shaped recessed portion in a second edge of said first and said second surfaces of said stiffener;

a third substantially rectangular shaped recessed portion in a third edge of said first and said second surfaces of said stiffener; and

a fourth substantially rectangular shaped recessed portion in a fourth edge of said first and said second surfaces of said stiffener.

24. The package of claim 22 , wherein at least one recessed portion includes:

a first substantially trapezoidal shaped recessed portion in a first edge of said first and said second surfaces of said stiffener;

a second substantially trapezoidal shaped recessed portion in a second edge of said first and said second surfaces of said stiffener;

a third substantially trapezoidal shaped recessed portion in a third edge of said first and said second surfaces of said stiffener; and

a fourth substantially trapezoidal shaped recessed portion in a fourth edge of said first and said second surfaces of said stiffener.

25. The package of claim 22 , wherein at least one recessed portion includes:

a first irregular shaped recessed portion in a first edge of said first and said second surfaces of said stiffener;

a second irregular shaped recessed portion in a second edge of said first and said second surfaces of said stiffener;

a third irregular shaped recessed portion in a third edge of said first and said second surfaces of said stiffener; and

a fourth irregular shaped recessed portion in a fourth edge of said first and said second surfaces of said stiffener.

26. The package of claim 22 , wherein said at least one recessed portion includes a first recessed portion that is substantially rectangular shaped and has an edge that coincides with said first edge of said cavity.

27. The package of claim 22 , wherein said at least one recessed portion includes a first recessed portion that is substantially trapezoidal shaped and has an edge that coincides with said first edge of said cavity.

28. The package of claim 22 , wherein said at least one recessed portion includes a first recessed portion that is irregular shaped and has an edge that coincides with said first edge of said cavity.

29. The package of claim 21 , wherein said at least one recessed portion includes a first recessed portion that has at least one notch formed in at least one edge of said first recessed portion.

30. The package of claim 21 , further comprising a wire bond that extends through a first recessed portion of said at least one recessed portion, wherein said wire bond couples a bond pad of said IC die to a first contact pad on said first surface of said substrate.

31. The package of claim 21 , further comprising a wire bond that couples a bond pad of said IC die to said first surface of said stiffener.

32. The package of claim 21 , wherein said protruding portion has a height such that a surface of said protruding portion is capable of being attached to a surface of a printed circuit board (PCB) when the BGA package is mounted to the PCB.

33. The package of claim 21 , wherein said stiffener is a heat spreader that conducts heat from said IC die.

34. A stiffener for stiffening a substrate in a ball grid array (BGA) package, comprising:

a substantially planar first surface having a centrally located cavity;

a substantially planar second surface opposed to said first surface, wherein said second surface has a centrally located protruding portion that opposes said centrally located cavity; and

at least one recessed portion in at least one edge of said first and said second surfaces, wherein said at least one recessed portion includes a first recessed portion that has at least one notch formed in at least one edge of said first recessed portion wherein the second surface is capable of attachment to the substrate such that said protruding portion extends through a centrally located window opening that is open at first and second surfaces of the substrate, and

wherein said first surface of said stiffener in said cavity is capable of mounting an integrated circuit die.

35. A stiffener for stiffening a substrate in a ball grid array (BGA) package, comprising:

a substantially planar first surface having a centrally located cavity;

a substantially planar second surface opposed to said first surface, wherein said second surface has a centrally located protruding portion that opposes said centrally located cavity; and

at least one recessed portion in at least one edge of said first and said second surfaces, wherein said at least one recessed portion is configured for at least one wire bond to extend therethrough wherein the second surface is capable of attachment to the substrate such that said protruding portion extends through a centrally located window opening that is open at first and second surfaces of the substrate, and

wherein said first surface of said stiffener in said cavity is capable of mounting an integrated circuit die.

36. A ball grid array (BGA) package, comprising:

a stiffener that has

a substantially planar first surface having a centrally located cavity,

a substantially planar second surface opposed to said first surface of said stiffener, wherein said second surface of said stiffener has a centrally located protruding portion that opposes said centrally located cavity, and

at least one recessed portion in an edge of said first and said second surfaces of said stiffener, wherein said at least one recessed portion includes a first recessed portion that has at least one notch formed in at least one edge of said first recessed portion;

a substantially planar substrate that has

a plurality of contact pads on a first surface of said substrate that are electrically connected through said substrate to a plurality of solder ball pads on a second surface of said substrate, and

a centrally located window opening that is open at said first and second surfaces of said substrate, wherein said substrate is attached to said second surface of said stiffener such that said protruding portion extends through said window opening; and

an IC die mounted to said first surface of said stiffener in said cavity.

37. A ball grid array (BGA) package, comprising:

a stiffener that has

a substantially planar first surface having a centrally located cavity,

a substantially planar second surface opposed to said first surface of said stiffener, wherein said second surface of said stiffener has a centrally located protruding portion that opposes said centrally located cavity, and

at least one recessed portion in an edge of said first and said second surfaces of said stiffener;

a substantially planar substrate that has

a plurality of contact pads on a first surface of said substrate that are electrically connected through said substrate to a plurality of solder ball pads on a second surface of said substrate, and

a centrally located window opening that is open at said first and second surfaces of said substrate, wherein said substrate is attached to said second surface of said stiffener such that said protruding portion extends through said window opening;

an IC die mounted to said first surface of said stiffener in said cavity; and

a wire bond that extends through a first recessed portion of said at least one recessed portion, wherein said wire bond couples a bond pad of said IC die to a first contact pad on said first surface of said substrate.