Thermal interface material with mixed aspect ratio particle dispersions
View Patent ↗An electron package includes an interface member between an electronic component and a thermal dissipation member. The interface member is highly efficient in transmitting thermal energy and/or suppressing electromagnetic radiation, with a particle filler dispersion including a combination of substantially spherical particles and substantially platelet-shaped particles within dispersion attribute ranges.
1. A thermal interface material positionable in proximity to a heat source for thermal dissipation from the heat source and for shielding of electromagnetic interference, said thermal interface material comprising:
a polymer matrix; and
thermally conductive particulate filler dispersed in said polymer matrix at 40-50% by volume, said particulate filler including substantially spherical alumina particles having an aspect ratio of between 0.8-1.2 and a spherical particle diameter, and platelet particles having a length, a width, and a thickness and a platelet particle diameter, wherein said length and said width are each greater than said thickness, said platelet particles having an aspect ratio of at least 10, a volumetric loading ratio of said platelet particles to said spherical alumina particles being between 0.1:1 and 0.2:1, and a particle diameter ratio of said platelet particle diameter to said spherical particle diameter being between 1:1 and 20:1, said platelet particles consist of boron nitride,
wherein said thermal interface material exhibits a thermal conductivity of at least 0.5 W/m*K, and a compressive modulus of less than 5 MPa at 20° C.
2. A thermal interface material as in claim 1 which exhibits an electromagnetic radiation absorption of at least 10 dB/in at 2.4 GHz.
3. A thermal interface material as in claim 1 wherein said platelet particles have an aspect ratio of at least 100.
4. A thermal interface material as in claim 3 wherein said length and said width of said platelet particles are about equal.
5. A thermal interface material as in claim 1 wherein said polymer matrix is a thermoplastic elastomer.
6. An electronic package, comprising:
an electronic component;
a heat dissipation member; and
the thermal interface material of claim 1 disposed between and in contact with said electronic component and said heat dissipation member.
7. A thermal interface material positionable in proximity to a heat source for thermal dissipation from the heat source and for shielding of electromagnetic interference, said thermal interface material comprising:
a polymer matrix; and
thermally conductive particulate filler dispersed in said polymer matrix at 25-45% by volume, said particulate filler including substantially spherical alumina particles having an aspect ratio between 0.8-1.2 and a spherical particle diameter, and platelet particles having a length, a width, and a thickness and a platelet particle diameter, wherein said length and said width are each greater than said thickness, said platelet particles having an aspect ratio of at least 10, a volumetric loading ratio of said platelet particles to said spherical alumina particles being between 0.1:1 and 0.2:1, and a particle diameter ratio of said platelet particle diameter to said spherical particle diameter being between 1:1 and 10:1, said platelet consists of graphene,
wherein said thermal interface material exhibits a thermal conductivity of at least 0.5 W/m*K, and a compressive modulus of less than 5 MPa at 20° C.
8. A thermal interface material as in claim 7 which exhibits an electromagnetic radiation absorption of at least 10 dB/in at 2.4 GHz.
9. A thermal interface material as in claim 7 wherein said platelet particles have an aspect ratio of at least 100.
10. A thermal interface material as in claim 9 wherein said length and said width of said platelet particles are about equal.
11. A thermal interface material as in claim 7 wherein said polymer matrix is a thermoplastic elastomer.
12. A thermal interface material as in claim 7 wherein said thermally conductive filler is dispersed in said polymer matrix at 35-45% by volume.
13. An electronic package, comprising:
an electronic component;
a heat dissipation member; and
the thermal interface material of claim 7 disposed between and in contact with said electronic component and said heat dissipation member.