High-Performance Thermal Interface Materials with Magnetic Aligned Carbon Fibers

Abstract

Thermal interface materials with high thermal conductivity and low hardness are crucial to the heat dissipation of high-power electronics. In this study, a high magnetic field was used to align the milled carbon fibers (CFs, 150 μm) in silicone rubber matrix to fabricate thermal interface materials with an ordered and discontinuous structure. The relationship among the magnetic field density, the alignment degree of CFs, and the properties of the resulting composites was explored by experimental study and theoretical analysis. The results showed higher alignment degree and enhanced thermal conductivity of composites under increased magnetic flux density within a certain curing time. When the magnetic flux density increased to 9 T, the CFs showed perfect alignment and the composite showed a high thermal conductivity of 11.76 W/(m·K) with only 20 vol% CF loading, owing to the ordered structure. Meanwhile, due to the low filler loading and discontinuous structure, a low hardness of 60~70 (shore 00) was also realized. Their thermal management performance was further confirmed in a test system, revealing promising applications for magnetic aligned CF–rubber composites in thermal interface materials.

Ultrahigh thermal conductive polymer composites by the 3D printing induced vertical alignment of carbon fiber

“…† The lowest thermal conductivity is of the composite materials with random structures prepared by casting, 12,46,47 and their thermal conductivity is lower than 10 W m −1 K −1 . Due to the weak driving force, the composite prepared by approaches of ice template, 28,48,49 magnetic eld, 11,50,51 and electric eld 23,52,53 is not enough to align the high content of ller, so it only obtains slightly higher thermal conductivity. In contrast, satisfactory values were obtained for composites with strong mechanical stress induced 18,22,54 orientation.…”

Enhanced thermal management in electronic devices through control-oriented structures

“…64 Incorporating magnetic particles into non-magnetic materials enables them to be oriented in a magnetic field as well. For example, CFs, 8,13 BN, 65–69 graphene, 70–72 graphite and CNTs 73 were oriented in magnetic field by modifying with magnetic particles (Fe 3 O 4 , FeCo), as shown in Fig. 6a–e.…”

“…There is a consensus that constructing three-dimensional heat conduction pathways or aligning llers in a specic direction can signicantly enhance the thermal conductivity of composites. 7,8 In recent years, there has been signicant attention towards vertically aligned structures (i.e., the llers are aligned in the direction perpendicular to the contact surface), due to their outstanding structural performance and advanced anisotropic functionalities. 7,[9][10][11][12][13][14][15][16][17] Aligning high thermal conductivity llers within a polymer matrix is a prevalent approach to enhance the thermal performance of composite materials.…”

Multi-scale hybrid spherical graphite composites: a light weight thermal interface material with high thermal conductivity and simple processing technology

“…For high thermal conductivity fillers, the commonest morphologies are spherical, 19 fibrous 20–22 and flaky. 23 Among these three types of fillers, fibrous and flaky fillers can form well thermal conduction paths at low filling content.…”

“…Hence, high thermal conducting llers as heat transfer media are generally added to the pure polymers to improve their heat conduction capacity. [16][17][18] For high thermal conductivity llers, the commonest morphologies are spherical, 19 brous [20][21][22] and aky. 23 Among these three types of llers, brous and aky llers can form well thermal conduction paths at low lling content.…”