Thermal vias disposed in a substrate without a liner layer
An apparatus relating generally to a substrate is disclosed. In such an apparatus, the substrate has formed therein a plurality of vias. A liner layer is located on the substrate, including being located in a subset of the plurality of vias. At least one of the plurality of vias does not have the liner layer located therein. A thermally conductive material is disposed in the at least one of the plurality of vias to provide a thermal via structure.
1. An apparatus, comprising:
a substrate having formed therein a plurality of vias;
a liner layer located on the substrate including being located in a subset of the plurality of vias;
wherein at least one of the plurality of vias does not have the liner layer located therein;
a thermally conductive material disposed in the at least one of the plurality of vias without a liner layer to provide a thermal via structure for conducting heat from one die to another die to conduct to a heat sink; and
a conductive material different than the thermally conductive material disposed in the subset of the plurality of vias having the liner layer.
2. The apparatus according to claim 1 , further comprising:
a barrier layer disposed in the at least one of the plurality of vias to provide the thermal via structure;
wherein the barrier layer is disposed between the thermally conductive material and the substrate; and
wherein the barrier layer provides sufficient protection against diffusion of the thermally conductive material into the substrate.
3. The apparatus according to claim 2 , wherein the thermally conductive material has a thermal conductivity value equal to or greater than approximately 150 W/(mK).
4. The apparatus according to claim 3 , wherein the thermally conductive material includes a metal.
5. The apparatus according to claim 4 , wherein the metal is selected from a group consisting of aluminum, copper, gold, silver, tungsten, and solder.
6. The apparatus according to claim 2 , wherein the barrier layer has a thermal conductivity value in a range of approximately 5 to 70 W/(mK).
7. The apparatus according to claim 2 , wherein the liner layer has a thermal conductivity value equal to or less than approximately 3 W/(mK).
8. The apparatus according to claim 2 , wherein the thermally conductive material includes a carbon-based material.
9. The apparatus according to claim 8 , wherein the carbon-based material includes graphene.
10. The apparatus according to claim 1 , wherein the at least one thermal via structure is a portion of a through die thermal via.
11. The apparatus according to claim 10 , wherein the through die thermal via is of an integrated circuit die of a die stack.
12. An apparatus, comprising:
a substrate having formed therein a plurality of vias;
at least one of the plurality of vias being an electrically conductive via having an electrically insulating liner layer between the via and at least a portion of the substrate, the electrically conductive via including a first conductive material; and
at least one other of the plurality of vias being a thermally conductive via that directly contacts at least a portion of the substrate, the thermally conductive via coupled to a heat sink, the thermally conductive via including a second conductive material that is different than the first conductive material.
13. The apparatus according to claim 12 , wherein the thermally conductive via does not have the liner layer located therein.
14. The apparatus according to claim 12 , wherein the thermally conductive via comprises a barrier layer disposed therein.
15. The apparatus according to claim 12 , wherein the thermally conductive via is not coupled for conducting an electrical signal.
16. The apparatus according to claim 12 , wherein the thermally conductive via is extends through the substrate between an upper surface and a lower surface thereof.
17. An apparatus, comprising:
a substrate having formed therein a plurality of vias;
a liner layer located in a subset of the plurality of vias, at least one of the plurality of vias not having the liner layer located therein;
a thermally conductive material disposed in the at least one of the plurality of vias to provide a thermal via structure for conducting heat from one die to another die;
a heat sink coupled to the thermal via structure for conduction of heat from the substrate to the heat sink; and
an electrically conductive material different than the thermally conductive material disposed in the subset of the plurality of vias having the liner layer.
18. The apparatus according to claim 17 , further comprising a barrier layer disposed in the at least one of the plurality of vias to provide the thermal via structure.
19. The apparatus according to claim 17 , wherein the thermal via structure is not coupled for conducting an electrical signal.