Devices employing thermal and mechanical enhanced layers and methods of forming same
A method includes attaching a first-level device die to a dummy die, encapsulating the first-level device die in a first encapsulating material, forming through-vias over and electrically coupled to the first-level device die, attaching a second-level device die over the first-level device die, and encapsulating the through-vias and the second-level device die in a second encapsulating material. Redistribution lines are formed over and electrically coupled to the through-vias and the second-level device die. The dummy die, the first-level device die, the first encapsulating material, the second-level device die, and the second encapsulating material form parts of a composite wafer.
1. A package comprising:
a dummy die;
an adhesive film over and contacting the dummy die;
a first-level device die over and attached to the dummy die through the adhesive film;
a first encapsulating material encapsulating the first-level device die;
a second-level device die over the first-level device die;
a plurality of through-vias overlapping and electrically connecting to the first-level device die, wherein the plurality of through-vias are at a same level as the second-level device die;
a second encapsulating material encapsulating the second-level device die and the plurality of through-vias therein; and
redistribution lines over and electrically coupling to the plurality of through-vias and the second-level device die.
2. The package of claim 1 , wherein the dummy die comprises a silicon plate.
3. The package of claim 1 , wherein the dummy die comprises a metal plate.
4. The package of claim 1 , wherein the adhesive film comprises a first edge and a second edge, with the first edge and the second edge being opposite edges of the adhesive film, and the first edge and the second edge are flush with a third edge and a fourth edge, respectively, of the first-level device die.
5. The package of claim 1 , wherein the first encapsulating material comprises a portion encircling the dummy die, and the portion of the first encapsulating material is level with the dummy die.
6. The package of claim 1 further comprising:
a dielectric layer overlapping the first-level device die and the first encapsulating material, wherein the dielectric layer separates the first encapsulating material from the second encapsulating material.
7. A package comprising:
a rigid dummy die;
a first die-attach film and a second die-attach film over the rigid dummy die;
a first device die and a second device die attached to the rigid dummy die through the first die-attach film and the second die-attach film, respectively;
a first encapsulating material encapsulating the first device die, the second device die, and the rigid dummy die therein;
a dielectric layer overlapping the first device die, the second device die, and the first encapsulating material;
a third device die over the dielectric layer, wherein the third device die comprises a first portion overlapping a portion of the first device die, and a second portion overlapping a portion of the second device die; and
a second encapsulating material encapsulating the third device die therein.
8. The package of claim 7 further comprising:
a through-via penetrating through the dielectric layer and the second encapsulating material, wherein the through-via has a bottom surface contacting a top surface of an electrical connector in the first device die.
9. The package of claim 8 , wherein a top surface of the through-via is substantially coplanar with a top surface of the second encapsulating material.
10. The package of claim 7 further comprising a second dielectric layer overlapping and contacting a top surface of the second encapsulating material and a top surface of the third device die.
11. The package of claim 7 , wherein the first encapsulating material further encapsulates the first die-attach film and the second die-attach film therein.
12. The package of claim 7 , wherein the rigid dummy die comprises silicon, and the rigid dummy die has no active devices therein.
13. The package of claim 7 further comprising:
a fourth device die overlapping a first portion of the third device die;
a third encapsulating material encapsulating the fourth device die therein; and
an additional through-via overlapping a second portion of the third device die, and the additional through-via penetrates through the third encapsulating material.
14. The package of claim 7 , wherein the first encapsulating material extends to a level lower than a bottom surface of the rigid dummy die.
15. A package comprising:
a blank die free from active devices, passive devices, and conductive lines therein;
a first device die over and attached to the blank die through an adhesive film, wherein the first device die comprises a conductive pillar;
a first encapsulating material encapsulating the first device die therein;
a dielectric layer comprising a bottom surface contacting a top surface of the first device die and a top surface of the first encapsulating material;
a second encapsulating material over the dielectric layer; and
a through-via penetrating through the second encapsulating material and the dielectric layer to contact the conductive pillar of the first device die.
16. The package of claim 15 , wherein the blank die extends beyond edges of the first device die.
17. The package of claim 16 , wherein edges of the blank die are flush with respective edges of the first encapsulating material and the second encapsulating material.
18. The package of claim 15 , wherein the adhesive film is encapsulated in, and is in contact with, the second encapsulating material.
19. The package of claim 15 further comprising:
a second device die encapsulated in the second encapsulating material, wherein the second device die overlaps a first portion of the first device die, and the second encapsulating material and the through-via overlap a second portion of the first device die.
20. The package of claim 1 , wherein the first encapsulating material physically contacts the adhesive film.