Method and structure for a three-dimensional package

1 . A method comprising:

aligning a bond pad of a second die to a first bond pad metal of a first die, the first die including the first bond pad metal and a second bond pad metal, the second bond pad metal adjacent to the first bond pad metal;

bonding a second dielectric bond layer of the second die to a first dielectric bond layer of the first die;

bonding the bond pad of the second die with the first bond pad metal of the first die, the bond pad of the second die interfacing directly with the first bond pad metal; and

adjoining the second dielectric bond layer of the second die to the second bond pad metal of the first die, wherein the second bond pad metal of the first die protrudes laterally from an edge of the second die.

2 . The method of claim 1 , wherein bonding the second dielectric bond layer of the second die, bonding the bond pad of the second die, and adjoining the second dielectric bond layer of the second die occur in a same joining process.

3 . The method of claim 2 , wherein the joining process comprises:

placing the second die on the first die;

pressing the bond pad of the second die against the first bond pad metal of the first die, the second dielectric bond layer of the second die against the first dielectric bond layer of the first die, and the second dielectric bond layer of the second die against the second bond pad metal of the first die; and

annealing the combination of the second die and the first die, to interdiffuse a metallic material of the bond pad of the second die with the first bond pad metal of the first die, to form dielectric-to-dielectric bonds between the second dielectric bond layer of the second die and the first dielectric bond layer of the first die, and to form chemical bonds between the second dielectric bond layer of the second die and the second bond pad metal of the first die.

4 . The method of claim 1 , wherein the first bond pad metal of the first die is arranged in a first set of bond pads, wherein the second bond pad metal of the first die is arranged in a second set of bond pads.

5 . The method of claim 4 , wherein first bond pads of the first set of bond pads are separated from each other by a first pitch, wherein second bond pads of the second set of bond pads are separated from each other by the first pitch.

6 . The method of claim 1 , wherein the bond pad of the second die is a first bond pad, wherein the second die is a bridge die, further comprising:

attaching the first die to a carrier;

attaching a third die to the carrier;

depositing a first encapsulant on the carrier, the first encapsulant laterally surrounding the first die and the third die;

forming the first dielectric bond layer of the first die over the first encapsulant and over the first die and the third die;

forming the first bond pad metal of the first die in the first dielectric bond layer over the first die;

forming a third bond pad metal of the third die in the first dielectric bond layer over the third die;

bonding a second bond pad of the second die with the third bond pad metal of the third die; and

adjoining the second dielectric bond layer of the second die to a fourth bond pad metal of the third die.

7 . The method of claim 6 , further comprising:

bonding a first bond pad of a fourth die to the first bond pad metal of the first die;

bonding a first bond pad of a fifth die to the third bond pad metal of the third die, the fourth die laterally separated from the second die by a first distance, the second die having a first thickness, the fourth die and fifth die having a second thickness, the second thickness being 5 to 15 times the first thickness; and

depositing a second encapsulant over the first encapsulant, over the first die, over the second die, over the third die, over the fourth die, and over the fifth die, the second encapsulant contacting an upper portion of the first die between the second die and the fourth die.

8 . The method of claim 7 , wherein a ratio of the first thickness to the first distance is 1:1 to 1:3.

9 . A method comprising:

attaching a bridge die to a first die and a second die, the bridge die electrically coupling the first die to the second die, the bridge die having a first thickness;

attaching a third die to the first die and a fourth die to the second die, the bridge die interposed between the third die and the fourth die, the third die having a second thickness, the fourth die having a third thickness, wherein each of the second thickness and the third thickness are between 5 times and 15 times the first thickness;

depositing an encapsulant over the bridge die, the first die and the second die to laterally surround the third die, the fourth die, and the bridge die; and

grinding an upper surface of the encapsulant and an upper portion of the third die and the fourth die until each of the second thickness and the third thickness is between 3 times and 10 times the first thickness.

10 . The method of claim 9 , further comprising:

forming a dummy support pad at an upper surface of the first die and the second die, wherein attaching the bridge die comprises adjoining a dielectric bonding layer of the bridge die with the dummy support pad.

11 . The method of claim 10 , wherein the dummy support pad extends laterally beyond an edge of the bridge die such that a first portion of the dummy support pad has an interface with the bridge die and a second portion of the dummy support pad is exposed from the bridge die.

12 . The method of claim 11 , wherein the dummy support pad is disposed at a corner of the bridge die, the second portion of the dummy support pad is exposed from the bridge die along a first side of the bridge die, a third portion of the dummy support pad exposed from the bridge die along a second side of the bridge die.

13 . The method of claim 10 , wherein the dummy support pad has a linear configuration in a plan view, a first line portion of the dummy support pad meeting a second line portion of the dummy support pad intersecting at a corner of the bridge die.

14 . The method of claim 9 , wherein a first distance is a shortest distance between the bridge die and the third die, wherein a ratio of the first distance to the first thickness is between 3:1 and 1:1.

15 . The method of claim 9 , wherein the first thickness is between 15 μm and 25 μm.

16 . A package structure comprising:

a first die, the first die comprising a first bond pad and a dummy bond structure disposed at a first surface thereof, the first bond pad and the dummy bond structure laterally surrounded by a first dielectric bonding layer; and

a second die, the second die comprising a second bond pad disposed at a second surface thereof, the second bond pad laterally surrounded by a second dielectric bonding layer, the second bond pad directly bonded to the first bond pad, an interior portion of the second dielectric bonding layer bonded to the first dielectric bonding layer, and an edge of the second dielectric bonding layer partially overlaps the dummy bond structure.

17 . The package structure of claim 16 , wherein the dummy bond structure corresponds to a corner of the second die, the corner of the second die contacting the dummy bond structure.

18 . The package structure of claim 17 , wherein the dummy bond structure comprises a first line segment extending along a first edge of the second die and a second line segment extending along a second edge of the second die, the first line segment and the second line segment meeting at the corner of the second die.

19 . The package structure of claim 16 , further comprising:

a third die disposed adjacent the first die and separated from the first die by a first distance;

a fourth die attached to the third die;

a bridge die attached to both the first die and the third die, the bridge die spanning the first distance, a thickness of the bridge die being a first thickness, a thickness of the second die being a second thickness, wherein the second thickness is 3 to 10 times the first thickness; and

an encapsulant laterally surrounding the second die, the fourth die, and the bridge die, the encapsulant completely filling a space between the bridge die and the second die, the space having a width between 1 and 3 times the first thickness.

20 . The method of claim 1 , wherein a corner of the second die partially overlaps the second bond pad metal of the first die in a plan view.