Methods and apparatuses for providing stacked-die devices
View Patent ↗Methods and apparatuses to provide a stacked-die device comprised of stacked sub-packages. For one embodiment of the invention, each sub-package has interconnections formed on the die-side of the substrate for interconnecting to another sub-package. The dies and associated wires are protected by an encapsulant leaving an upper portion of each interconnection exposed. For one embodiment of the invention the encapsulant is a stencil-printable encapsulant and the upper portion of the interconnection is exposed by use of a patterned stencil during application of the encapsulant.
1. An apparatus comprising:
a first substrate having a top surface and bottom surface;
a set of one or more dies attached to the top surface of the first substrate, the one or more dies extending above the top surface a first distance;
one or more interconnections formed on the top surface of the first substrate, the one or more interconnections extending above the top surface a second distance;
a planar encapsulant disposed upon the top surface of the first substrate and extending above the top surface a third distance, the third distance greater than the first distance and less than the second distance such that the one or more dies are encapsulated and a portion of the one or more interconnections are exposed; and
a second substrate above the first substrate, the second substrate having a bottom surface and one or more conductive pads formed on the bottom surface of the second substrate, each conductive pad extending from the bottom surface of the second substrate down to the second distance without extending to the third distance.
2. The apparatus of claim 1 wherein the one or more dies are attached to one another in a stacked-die configuration and the uppermost portion of an uppermost die extends above the top surface the first distance.
3. The apparatus of claim 1 wherein the one or more dies have associated wires, the associated wires extending above the top surface a fourth distance, the fourth distance less than the first distance such that the associated wires are encapsulated.
4. The apparatus of claim 1 wherein the encapsulant is a thermal setting material.
5. The apparatus of claim 1 wherein
the second substrate further has a top surface and a second set of one or more dies attached to the top surface of the second substrate, and each conductive pad is electrically coupled to a corresponding interconnection of the one or more interconnections formed on the top surface of the first substrate.
6. The apparatus of claim 4 wherein the thermal setting material is an epoxy.
7. The apparatus of claim 3 wherein the associated wires of one or more of the dies comprise wire-bonds.
8. The apparatus of claim 1 wherein one or more of the dies has a logic processor device implemented thereon.
9. A system comprising:
a first sub-package; and
a second sub-package, the second sub-package stacked atop the first sub-package and electrically connected thereto, each of the first sub-package and the second sub-package including a substrate having one or more dies attached to a top surface of the substrate and one or more interconnections formed upon the top surface of the substrate, and a stencil-printable encapsulant stencil-printed onto the top surface of the substrate such that the one or more dies are encapsulated and an upper portion of each of the one or more interconnections is exposed, wherein the encapsulant of the first sub-package has a planar top surface and the upper portion of each of the one or more interconnections of the first sub-package extends above the planar top surface, and the substrate of the second sub-package has one or more conductive pads formed on a bottom surface, each conductive pad extending down from the bottom surface of the substrate of the second sub-package, contacting a corresponding interconnection of the first sub-package, without extending to the planar top surface.
10. The system of claim 9 wherein each conductive pad is electrically coupled to the corresponding interconnection of the one or more interconnections formed upon the top surface of the substrate of the first sub-package.
11. The system of claim 10 further comprising:
one or more additional sub-packages stacked successively atop the second sub-package, each additional sub-package including a substrate having one or more dies attached to a top surface of the substrate and one or more interconnections formed upon the top surface of the substrate, and an encapsulant disposed upon the top surface of the substrate such that the one or more dies are encapsulated and an upper portion of each of the one or more interconnections is exposed, and one or more conductive areas formed on a bottom surface, each conductive area electrically coupled to a corresponding interconnection of the one or more interconnections formed upon the top surface of the substrate of an immediately preceding sub-package.
12. The system of claim 9 wherein the one or more dies are attached to one another in a stacked-die configuration.
13. The system of claim 9 wherein the one or more dies have associated wires, the associated wires completely encapsulated by the encapsulant.
14. The system of claim 13 wherein the associated wires of one or more of the dies comprise wire-bonds.
15. The system of claim 9 wherein the encapsulant is a thermal setting material.
16. The system of claim 15 wherein the thermal setting material is an epoxy.
17. The system of claim 9 wherein one or more of the dies implements a logic processor device.
18. The system of claim 16 wherein the thermal setting material contains a flux.
19. The system of claim 9 wherein the encapsulant contains 0–80% silica.
20. The system of claim 9 wherein the encapsulant contains a viscosity decreasing solvent.