Package assembly for embedded die and associated techniques and configurations

1. A method of fabricating a package assembly, the method comprising:

providing a die attach layer having a first side and a second side, wherein the die attach layer is an electrically insulative material, wherein the second side of the die attach layer is exposed to couple with an electrical component by one or more package-level interconnects;

coupling a die with the die attach layer, the die having an active side including active devices of the die and an inactive side disposed opposite to the active side, the inactive side of the die coupled to the first side of the die attach layer, wherein the die attach layer is used as a substrate for attachment of the die and the die is in direct contact with the die attach layer;

coupling a reinforced plate with the die attach layer, the reinforced plate having an electrically conductive core, a first side and a second side disposed opposite to the first side and a cavity disposed in the reinforced plate, the first side of the reinforced plate coupled with the first side of the die attach layer and the die is disposed in the cavity; and

forming one or more build-up layers on the second side of the reinforced plate, the one or more build-up layers including an insulator and conductive features disposed in the insulator, the conductive features being electrically coupled with the die, wherein the inactive side of the die is in direct contact with the die attach layer, the first side of the reinforced plate is in direct contact with the die attach layer and the die is disposed in the cavity.

2. The method of claim 1 , further comprising:

prior to forming the one or more build-up layers, depositing a die encapsulant material in the cavity and at least partially encapsulating the active side of the die; and

forming via structures that extend through the die encapsulant material using a laser drilling process, wherein the die is electrically coupled with electrical routing features of the one or more build-up layers through the via structures subsequent to forming the one or more build-up layers.

3. The method of claim 2 , wherein depositing the die encapsulant material comprises:

applying a laminate layer on the second side of the reinforced plate; and

hot pressing the laminate layer to couple the laminate layer with the reinforced plate and substantially fill the cavity with prepreg material of the laminate layer.

4. The method of claim 1 , wherein the die is a first die, the method further comprising electrically coupling a second die with the first die.

5. The method of claim 4 , wherein electrically coupling the second die with the first die comprises electrically coupling the second die with the first die through the electrical routing features of the one or more build-up layers, the method further comprising:

forming package-level interconnects that are electrically coupled with the first die and the second die through the die attach layer and through plated through holes (PTHs) disposed in the reinforced plate, the PTHs configured to route electrical signals of the first die and the second die to the package-level interconnects.

6. The method of claim 5 , wherein the one or more build-up layers, the reinforced plate and the die attach layer are part of a first package substrate and the package-level interconnects are first package-level interconnects configured to couple the first package substrate with a circuit board, the method further comprising:

coupling a second package substrate with the first package substrate using second package-level interconnects, the second package substrate including a third die mounted on or embedded in the second package substrate, the third die being electrically coupled with the first package substrate through the second package-level interconnects, wherein the second die is disposed between the first package substrate and the second package substrate.

7. The method of claim 4 , wherein:

the first die includes through silicon vias (TSVs) disposed between the active side and the inactive side of the first die; and

electrically coupling the second die with the first die comprises electrically coupling the second die with the TSVs through the inactive side of the first die using interconnects that extend through the die attach layer.

8. The method of claim 7 , wherein the one or more build-up layers, the reinforced plate and the die attach layer are part of a first package substrate, the method further comprising:

forming first package-level interconnects that are configured to couple the first package substrate with a circuit board; and

coupling a second package substrate with the first package substrate using second package-level interconnects that are configured to route electrical signals between the first package substrate and the second package substrate through the die attach layer, the second package substrate including a third die mounted on or embedded in the second package substrate, the third die being electrically coupled with the first package substrate through the second package-level interconnects.

9. The method of claim 1 , wherein:

providing a die attach layer comprises providing a B-stage resin on a panel; and

coupling a die with the die attach layer and coupling a reinforced plate with the die attach layer are simultaneously performed using a hot press process to attach the die and reinforced plate with the B-stage resin.

10. The method of claim 1 , wherein providing the die attach layer includes providing openings in the die attach layer to expose interconnects of the first side of the reinforced plate to couple with the one or more package-level interconnects through the openings of the die attach layer.