Packages with liquid metal as heat-dissipation media and method forming the same

1 . A method comprising:

attaching a permeable plate to a metal lid, wherein the permeable plate comprises a metallic material;

dispensing a liquid-metal-comprising media to a first package component, wherein the first package component is over and bonded to a second package component, and wherein the liquid-metal-comprising media comprises a liquid metal therein; and

attaching the metal lid to the second package component, wherein during the attaching, the liquid-metal-comprising media migrates into the permeable plate to form a composite thermal interface material.

2 . The method of claim 1 , wherein at a time after the liquid-metal-comprising media is dispensed to the first package component and before the metal lid is attached to the second package component, the liquid-metal-comprising media is a solid plate.

3 . The method of claim 2 , wherein the liquid metal is molten during the attaching the metal lid to the second package component, and is molten by an elevated temperature, and wherein after the attaching, the liquid metal is returned to a solid state.

4 . The method of claim 3 , wherein the liquid metal is configured to be molten by heat generated in the first package component when the first package component is powered up.

5 . The method of claim 1 , wherein at a time after the liquid-metal-comprising media is dispensed to the first package component and before the metal lid is attached to the second package component, the liquid metal is in a liquid form.

6 . The method of claim 5 , wherein the liquid-metal-comprising media further comprises solid particles mixed in the liquid metal.

7 . The method of claim 1 further comprising dispensing a blocker on the first package component, wherein the liquid-metal-comprising media is encircled by the blocker.

8 . The method of claim 1 further comprising dispensing a solid thermal interface material on the first package component, wherein the first package component comprises a device die and a molding compound encircling the device die, and wherein the solid thermal interface material overlaps the molding compound, and the liquid-metal-comprising media is over and contacting the device die.

9 . The method of claim 1 , wherein after the attaching, the liquid-metal-comprising media penetrates through the permeable plate to contact the metal lid.

10 . The method of claim 1 , wherein the attaching the permeable plate to the metal lid comprises attaching a metal mesh to the metal lid, wherein the metal mesh comprises woven metal wires.

11 . A method comprising:

placing a first package component;

attaching a second package component over the first package component;

attaching an adhesive over the first package component;

attaching a metal lid to the first package component through the adhesive, wherein a composite thermal interface material is formed between, and in physical contact with both of, the second package component and the metal lid, and wherein the composite thermal interface material comprises:

a permeable plate; and

a liquid-metal-comprising media in the permeable plate, wherein the liquid-metal-comprising media comprises a liquid metal, and the liquid-metal-comprising media is a solid at room temperature, and wherein the attaching the metal lid comprises heating the liquid-metal-comprising media as a liquid during the attaching the metal lid to the first package component.

12 . The method of claim 11 , wherein the liquid-metal-comprising media is a paste at room temperature, and the method further comprises heating the liquid-metal-comprising media as a liquid during the attaching the metal lid to the first package component.

13 . The method of claim 11 , wherein:

at a first time before the attaching the metal lid to the first package component, the liquid-metal-comprising media and the permeable plate are discrete components; and

at a second time after the attaching the metal lid to the first package component, the liquid-metal-comprising media fills first parts of through-channels of the permeable plate, and wherein second parts of the through-channels in the permeable plate are air gaps.

14 . The method of claim 11 , wherein the composite thermal interface material comprises:

a first middle portion overlapping a second middle portion of the second package component, wherein the first middle portion has a first thickness; and

a first edge portion overlapping a second edge portion of the second package component, wherein the first edge portion has a second thickness different from the first thickness.

15 . The method of claim 11 further comprising attaching a solid thermal interface material between, and in physical contact with both of, the second package component and the metal lid.

16 . The method of claim 11 further comprising placing a blocker over the first package component, wherein the composite thermal interface material is encircled by the blocker.

17 . The method of claim 11 , wherein the permeable plate comprises a plurality of layers of wires.

18 . A method comprising:

encapsulating a device die in a molding compound;

dispensing a liquid-metal-comprising media as a paste over the molding compound and the device die;

after the liquid-metal-comprising media is dispensed, forming a composite thermal interface material over and contacting the molding compound and the device die, wherein the composite thermal interface material comprises:

a metal mesh; and

the liquid-metal-comprising media extending to opposing sides of the metal mesh, wherein the liquid-metal-comprising media comprises a liquid metal, and wherein the liquid metal comprises a material selected from the group consisting of a gallium-based alloy, a bismuth-base alloy, and combinations thereof.

19 . The method of claim 18 , wherein the liquid-metal-comprising media is a solid at room temperature, and the liquid-metal-comprising media is configured to change phase to a liquid when the device die is provided with power.

20 . The method of claim 18 , wherein the metal mesh comprises a plurality of layers of wires.