Discrete polymer in fan-out packages

1. A package comprising:

a first dielectric layer;

a first device die overlapping the first dielectric layer; and

a first plurality of redistribution lines extending into the first dielectric layer; and

a first encapsulant encapsulating the first device die therein, wherein a first top surface of the first encapsulant is coplanar with a second top surface of the first device die, and wherein the first encapsulant comprises:

a first portion overlapping a portion of the first dielectric layer; and

a second portion comprising a first sidewall contacting a second sidewall of the first dielectric layer to form an interface.

2. The package of claim 1 further comprising a second device die underlying and contacting the first dielectric layer, wherein the first plurality of redistribution lines are in contact with electrical features of the second device die.

3. The package of claim 1 further comprising a second encapsulant underlying and physically contacting the first encapsulant.

4. The package of claim 3 , wherein the second encapsulant comprises:

a base material comprising a third top surface; and

partial particles comprising fourth top surfaces coplanar with the third top surface, wherein the partial particles further comprise rounded lower surfaces.

5. The package of claim 3 , wherein a first edge of the first encapsulant and a corresponding second edge of the second encapsulant are parts of a same continuous and straight edge of the package.

6. The package of claim 3 , wherein the first dielectric layer and the second encapsulant form a first interface and a second interface, respectively with the first encapsulant, and the first interface and the second interface are parts of a continuous and planar interface.

7. The package of claim 1 further comprising:

a second dielectric layer over and contacting the first encapsulant, wherein first edges of the second dielectric layer are laterally recessed from corresponding second edges of the first encapsulant; and

a second plurality of redistribution lines extending into the second dielectric layer.

8. The package of claim 1 , wherein the first encapsulant encircles the first device die.

9. A package comprising:

a first plurality of dielectric layers;

a plurality of redistribution lines extending into the first plurality of dielectric layers;

a first device die overlapping the first plurality of dielectric layers;

a through-via overlapping the first plurality of dielectric layers and electrically coupling to one of the plurality of redistribution lines; and

a first encapsulant, with the first device die and the through-via being in the first encapsulant, wherein the first encapsulant contacts the first device die and the through-via, and the first encapsulant extends laterally beyond edges of the first plurality of dielectric layers.

10. The package of claim 9 , wherein the first encapsulant contacts a top surface of the first plurality of dielectric layers to form a horizontal interface, and the first encapsulant further contacts sidewalls of the first plurality of dielectric layers to form a vertical interface.

11. The package of claim 9 further comprising a through-via extension extending into the first plurality of dielectric layers, wherein the through-via is continuously connected to the through-via extension.

12. The package of claim 9 , wherein the first encapsulant has a first bottom surface coplanar with a second bottom surface of the first plurality of dielectric layers.

13. The package of claim 12 further comprising a second encapsulant underlying the first encapsulant, wherein both of the first bottom surface and the second bottom surface are in contact with a top surface of the second encapsulant.

14. The package of claim 13 further comprising a second device die encapsulated in the second encapsulant.

15. The package of claim 9 further comprising a second plurality of dielectric layers overlying and contacting the first encapsulant, wherein edges of the second plurality of dielectric layers are laterally recessed from corresponding edges of the first encapsulant.

16. The package of claim 15 further comprising a second encapsulant encapsulating the second plurality of dielectric layers therein.

17. A package comprising:

a first encapsulant;

a first device die encapsulated in the first encapsulant;

a first dielectric layer over and contacting both of the first device die and the first encapsulant;

a second encapsulant comprising:

a first portion overlapping the first dielectric layer; and

a second portion extending to a side of the first dielectric layer, the second portion comprising a bottom surface contacting a top surface of the first encapsulant; and

a second device die encapsulated in the second encapsulant.

18. The package of claim 17 , wherein the first encapsulant comprises partially spherical particles, and the partially spherical particles comprise planar top surfaces, and the planar top surfaces are parts of a top surface of the first encapsulant.

19. The package of claim 17 further comprising:

a second dielectric layer over the first encapsulant;

a third encapsulant comprising:

a third portion overlapping the second dielectric layer; and

a fourth portion comprising an additional bottom surface contacting an additional top surface of the second encapsulant.

20. The package of claim 17 , wherein the second encapsulant fully encircles the first dielectric layer therein.