Stacked-chip packages in package-on-package apparatus, methods of assembling same, and systems containing same

1. An apparatus comprising: a package substrate including a die side and a land side;

a chip stack disposed on the die side, wherein the chip stack includes a bottom chip disposed on the die side and a top chip disposed above the bottom chip, wherein the bottom chip is a flip-chip, wherein the bottom chip includes through-silicon vias, wherein the top chip is a wire-bond chip, and wherein the chip stack has an offset height;

an interposer disposed on the die side, the interposer including an opening extending therethrough, the chip stack positioned on the package substrate within the opening, the interposer surrounding the chip stack, wherein the interposer accommodates the offset height of the chip stack;

an encapsulant positioned between the chip stack and the interposer in the opening; an underfill material positioned between the package substrate and the bottom chip,

wherein the encapsulant is also positioned between the underfill material and the interposer; and a fill material positioned on the die side between the package substrate and the interposer,

the fill material including an inner surface adjacent to the encapsulant.

2. The apparatus of claim 1 , wherein the interposer includes a bottom side ball-grid array and a top side ball-grid array, the apparatus further including:

a top package, wherein the top package includes at least one microelectronic device, wherein the top package is mated to the interposer top side ball-grid array; and

wherein the interposer bottom side ball-grid array is mated to the die side of the package substrate.

3. The apparatus of claim 1 , wherein the chip stack includes a wire-bond second chip disposed between the bottom chip and the top chip.

4. The apparatus of claim 1 , wherein the chip stack includes: a through-silicon via (TSV)-coupled second chip disposed on the bottom chip,

the TSV-coupled second chip being electrically coupled to the package substrate using the through-silicon vias of the bottom chip; and

the top chip is disposed on the TSV-coupled second chip.

5. The apparatus of claim 1 , wherein the chip stack includes:

a through-silicon via (TSV)-coupled second chip disposed on the bottom chip, the TSV-coupled second chip being electrically coupled to the package substrate using the through-silicon vias of the bottom chip, the TSV-coupled second chip including through-silicon vias;

a TSV-coupled third chip disposed on the TSV-coupled second chip, the TSV-coupled third chip being electrically coupled to the package substrate using the through-silicon vias of the TSV-coupled second chip and the bottom chip; and

the top chip is a wire-bond fourth chip disposed on the TSV-coupled third chip.

6. The apparatus of claim 1 , wherein the chip stack includes:

a through-silicon via (TSV)-coupled second chip disposed on the bottom chip, the TSV-coupled second chip being electrically coupled to the package substrate using the through-silicon vias of the bottom chip, the TSV-coupled second chip including through-silicon vias;

a plurality of additional TSV-coupled chips disposed on the TSV-coupled second chip, wherein the plurality of additional TSV-coupled chips is in a range from 2 to 8 TSV-coupled chips; and

the top chip is disposed above the plurality of additional TSV-coupled chips.

7. The apparatus of claim 1 , wherein the chip stack includes:

a through-silicon via (TSV)-coupled second chip disposed on the bottom chip, the TSV-coupled second chip being electrically coupled to the package substrate using the through-silicon vias of the bottom chip, the TSV-coupled second chip including through-silicon vias;

a TSV-coupled third chip disposed on the TSV-coupled second chip, the TSV-coupled third chip being electrically coupled to the package substrate using the through-silicon vias of the TSV-coupled second chip and the bottom chip;

a wire-bond fourth chip disposed above the TSV-coupled third chip; and the top chip is disposed above the wire-bond fourth chip.

8. The apparatus of claim 1 , wherein the chip stack includes a plurality of intermediate chips between the bottom chip and the top chip, wherein at least one of the intermediate chips between the bottom chip and the top chip is a wire-bond chip, and at least one of the intermediate chips between the bottom chip and the top chip is a TSV-coupled chip.

9. The apparatus of claim 1 , wherein the chip stack includes a wire- bond second chip disposed on the bottom chip, and wherein the top chip is a disposed above the wire-bond second chip.

10. The apparatus of claim 1 , wherein the fill material comprises a cured material.

11. The apparatus of claim 1 , wherein the top chip has a width that is greater than that of the bottom chip.

12. An apparatus comprising: a package substrate including a die side and a land side;

a chip stack disposed on the die side, wherein the chip stack includes a bottom chip disposed on the die side, an intermediate chip disposed above the bottom chip, and a top chip disposed above the intermediate chip, wherein the bottom chip is a flip-chip, wherein the bottom chip includes through-silicon vias, wherein the intermediate chip is electrically coupled to the package substrate using the through-silicon vias of the bottom chip, wherein the top chip is electrically coupled to the package substrate using wire bonds, and wherein the chip stack has an offset height;

an interposer disposed on the die side, the interposer including an opening extending therethrough, the chip stack positioned on the package substrate within the opening, the interposer surrounding the chip stack, wherein the interposer accommodates the offset height of the chip stack;

an encapsulant positioned between the chip stack and the interposer in the opening; an underfill material positioned between the package substrate and the bottom chip,

wherein the encapsulant is also positioned between the underfill material and the interposer; and a fill material positioned on the die side between the package substrate and the interposer,

the fill material including an inner surface adjacent to the encapsulant.

13. The apparatus of claim 12 , further comprising a top package disposed on the interposer, wherein the top package includes at least one microelectronic device.

14. The apparatus of claim 12 , wherein the bottom chip comprises a processor, wherein the intermediate chip comprises a random-access memory (RAM) chip, wherein the top chip comprises an RF device.

15. The apparatus of claim 12 , wherein the intermediate chip includes through-silicon vias.

16. An apparatus comprising: a package substrate including a die side and a land side;

a chip stack disposed on the die side, wherein the chip stack includes a bottom chip disposed on the die side, a top chip disposed above the bottom chip, and an intermediate chip between the top chip and he bottom chip, wherein the bottom chip is a flip-chip, wherein the bottom chip includes through-silicon vias, wherein the top chip is a wire-bond chip, wherein the top chip has a width that is greater than that of the bottom chip, wherein the top chip has a thickness that is greater than that of the bottom chip, and wherein the chip stack has an offset height;

an interposer disposed on the die side, the interposer including an opening extending therethrough, the chip stack positioned on the package substrate within the opening, the interposer surrounding the chip stack, wherein the interposer accommodates the offset height of the chip stack;

an encapsulant positioned between the chip stack and the interposer in the opening; an underfill material positioned between the package substrate and the bottom chip,

wherein the encapsulant is also positioned between the underfill material and the interposer; and a fill material positioned on the die side between the package substrate and the interposer,

the fill material including an inner surface adjacent to the encapsulant.

17. The apparatus of claim 16 , wherein the bottom chip a footprint on a portion of the package substrate, and wherein the bottom chip is electrically coupled to the package substrate only through connections positioned in the footprint.

18. The apparatus of claim 16 , wherein the intermediate chip has a width that is equal to that of the bottom chip.

19. The apparatus of claim 16 , further comprising:

a plurality of wire bonds electrically coupling the top chip to the package substrate; a plurality of wire-bond pads on the package substrate, the wire bonds electrically

coupled to the wire-bond pads;

a plurality of bumps electrically coupling the bottom chip to the package substrate; and a plurality of die bump pads on the package substrate, the bumps electrically coupled to

the die bump pads;

wherein a distance between a wire-bond pad and an adjacent die bump pad is greater than a distance between adjacent die bump pads.

20. The apparatus of claim 16 , wherein the interposer includes a bottom side ball-grid array and a top side ball-grid array, the apparatus further including:

a top package, wherein the top package includes at least one microelectronic device, wherein the top package is mated to the interposer top side ball-grid array; and

wherein the interposer bottom side ball-grid array is mated to the die side of the package

substrate.