Method, apparatus, and assembly for thermally connecting layers
A die of an integrated circuit and an upper layer of a circuit assembly are thermally connected by applying a thermal interface material (TIM) on the die, such that the TIM is between the die and an upper layer. The TIM comprises an emulsion of liquid metal droplets and uncured polymer. The method further comprises compressing the circuit assembly thereby deforming the liquid metal droplets and curing the thermal interface material thereby forming the circuit assembly.
1. An integrated circuit assembly comprising:
a die;
an upper layer; and
a thermally interface material disposed in contact with the die and the upper layer, wherein the thermal interface material comprises a polymer and liquid metal droplets dispersed throughout the polymer, wherein a bondline distance formed between the die and the upper layer is no greater than 150 microns, wherein the liquid metal droplets are in a liquid phase at least at a temperature in a range of −19 degrees Celsius to 30 degrees Celsius.
2. The assembly of claim 1 , wherein the liquid metal droplets comprise gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, a mercury alloy, or a combination thereof.
3. The assembly of claim 1 , wherein the thermal interface material comprises a thermal resistance value of no greater than 30 (° K*mm 2 )/W.
4. The assembly of claim 1 , wherein the polymer comprises a thermosetting polymer.
5. The assembly of claim 1 , wherein the polymer comprises a thermoplastic polymer.
6. The assembly of claim 1 , wherein the liquid metal droplets are generally ellipsoidal.
7. The assembly of claim 1 , wherein the die comprises a processor.
8. The assembly of claim 1 , wherein the upper layer comprises a heat sink, an integrated heat spreader, or packaging.
9. The assembly of claim 1 , wherein a bondline distance formed between the die and the upper layer in the assembly is no greater than 100 microns.
10. The assembly of claim 1 , wherein a bondline distance formed between the die and the upper layer in the assembly is no greater than 70 microns.
11. The assembly of claim 1 , wherein a bondline distance formed between the die and the upper layer in the assembly is in a range of 15 microns to 90 microns.
12. The assembly of claim 1 , wherein the thermal interface material comprises a thermal resistance value of no greater than 10 (° K*mm 2 )/W.
13. The assembly of claim 1 , wherein the liquid metal droplets comprise a unimodal polydispersity.
14. The assembly of claim 1 , wherein the liquid metal droplets comprise a multimodal polydispersity.
15. The assembly of claim 1 , wherein the liquid metal droplets have an aspect ratio greater than 1.
16. The assembly of claim 1 , wherein the liquid metal droplets have an aspect ratio greater than 2 and the width of the liquid metal droplets is substantially aligned with a longitudinal place of the thermal interface material.