Package structure and method of forming the same
An embodiment is a structure including a first package including a first die, and a molding compound at least laterally encapsulating the first die, a second package bonded to the first package with a first set of conductive connectors, the second package comprising a second die, and an underfill between the first package and the second package and surrounding the first set of conductive connectors, the underfill having a first portion extending up along a sidewall of the second package, the first portion having a first sidewall, the first sidewall having a curved portion and a planar portion.
1 . A structure comprising:
a first package comprising:
a first die; and
a first molding compound encapsulating the first die;
a second package bonded to the first package with a first set of conductive connectors, the second package comprising a second die, a dielectric layer of the first package is disposed at a surface of the first package opposite the second package, the dielectric layer comprises a recess free of any metallic features, and the recess is surrounded by the dielectric layer in a top down view, wherein a lateral surface of the recess in the dielectric layer is curved; and
an underfill between the first package and the second package, the underfill surrounding the first set of conductive connectors, wherein the underfill comprises a curved portion that overlaps the recess.
2 . The structure of claim 1 , wherein the underfill extends along sidewalls of the second package.
3 . The structure of claim 2 , wherein the underfill extends from a top surface of the first package to a top surface of the second package.
4 . The structure of claim 2 , wherein a sidewall of the underfill further comprises:
a linear portion connected to the curved portion, the sidewall of the underfill extending along the sidewalls of the second package.
5 . The structure of claim 4 , wherein the second package further comprises a second molding compound encapsulating the second die, wherein a point where the curved portion adjoins the linear portion is above a bottom surface of the second molding compound.
6 . The structure of claim 1 further comprising:
an integrated passive device (IPD) component bonded to a first redistribution structure, the first redistribution structure being between the IPD component and the first die; and
a second set of conductive connectors bonded to the first redistribution structure.
7 . The structure of claim 1 , wherein the underfill is coterminous with the first package and is wider than the second package.
8 . A package comprising:
a first package comprising a first semiconductor die;
a second package over and bonded to the first package with a first set of conductive connectors, the second package comprising a second semiconductor die laterally encapsulated by a first molding compound; and
an underfill between the first package and the second package and surrounding the first set of conductive connectors, the underfill having a sidewall extending up along a sidewall of the first molding compound of the second package, the sidewall comprises:
a linear portion; and
a curved portion above and adjoined to the linear portion, wherein a point where the curved portion adjoins the linear portion is above a bottom surface of the first molding compound.
9 . The package of claim 8 , wherein the linear portion of the sidewall of the underfill is aligned with an exterior sidewall of the first package.
10 . The package of claim 8 , wherein the first package further comprises a redistribution structure under and electrically connected to the first semiconductor die, and wherein the redistribution structure comprises:
an insulating layer; and
a first recess in the insulating layer.
11 . The package of claim 10 , wherein the insulating layer encircles the first recess in a top down view.
12 . The package of claim 10 , wherein the redistribution structure further comprises:
a second recess in the insulating layer; and
a plurality of contact pads in the insulating layer, the plurality of contact pads being disposed between the first recess and the second recess.
13 . The package of claim 12 further comprising a passive device bonded to the plurality of contact pads.
14 . The package of claim 8 , wherein the curved portion of the underfill is concave.
15 . A structure comprising:
a first redistribution structure comprising metallization patterns in dielectric layers, a bottommost dielectric layer of the dielectric layers has a recess, the recess is bounded on opposing sides by portions of the bottommost dielectric layer, and the recess is free of any metallic features;
a first die over and electrically coupled to the first redistribution structure;
a molding compound encapsulating the first die;
a second redistribution structure over the molding compound;
a semiconductor package over and bonded to the second redistribution structure, the semiconductor package comprising a second die; and
an underfill between the semiconductor package and the second redistribution structure and extending along a sidewall of the semiconductor package, wherein a sidewall of the underfill that is opposite to the semiconductor package comprises:
a curved top portion; and
a bottom portion that is aligned with a sidewall of the first redistribution structure.
16 . The structure of claim 15 , wherein the bottom portion of the sidewall of the underfill that is opposite to the semiconductor package adjoins the curved top portion.
17 . The structure of claim 15 , wherein the bottom portion of the sidewall of the underfill that is opposite to the semiconductor package is further aligned with a sidewall of the molding compound.
18 . The structure of claim 15 , wherein the underfill extends from a top surface of the semiconductor package to the second redistribution structure.
19 . The structure of claim 15 , wherein the bottom portion of the sidewall of the underfill that is opposite to the semiconductor package is linear.