Emerging Flexible Thermally Conductive Films: Mechanism, Fabrication, Application

Abstract

Effective thermal management is quite urgent for electronics owing to their ever-growing integration degree, operation frequency and power density, and the main strategy of thermal management is to remove excess energy from electronics to outside by thermal conductive materials. Compared to the conventional thermal management materials, flexible thermally conductive films with high in-plane thermal conductivity, as emerging candidates, have aroused greater interest in the last decade, which show great potential in thermal management applications of next-generation devices. However, a comprehensive review of flexible thermally conductive films is rarely reported. Thus, we review recent advances of both intrinsic polymer films and polymer-based composite films with ultrahigh in-plane thermal conductivity, with deep understandings of heat transfer mechanism, processing methods to enhance thermal conductivity, optimization strategies to reduce interface thermal resistance and their potential applications. Lastly, challenges and opportunities for the future development of flexible thermally conductive films are also discussed.

Self-Modifying Nanointerface Driving Ultrahigh Bidirectional Thermal Conductivity Boron Nitride-Based Composite Flexible Films

“…This study provides an innovative design principle to tailor composite interfaces and opens With the rapid development of high-power and highfrequency electronic devices, thermal interface materials (TIMs) applied between heat sources and heat sinks have become vital components to remove excess heat from electronic systems [1]. Given the easy processing, low density and good flexibility properties of polymers, state-of-theart TIMs are made up of polymer-based composites with high thermal conductivity fillers, such as metal, carbon and ceramic materials [2]. In particular, boron nitride (BN) has attracted tremendous attention during the past decades because of its excellent intrinsic thermal conductivity and electronic insulation, which are indispensable for electronic devices [3][4][5][6][7][8].…”

Development and Perspectives of Thermal Conductive Polymer Composites

“…Fillers commonly used in thermal conductive polymer composites include three types: metal fillers (silver, copper, aluminum), carbon-based fillers (carbon nanotubes, carbon fibers, graphene), and ceramic fillers (aluminum oxide, aluminum nitride, boron nitride) [ 2 , 17 , 25 , 26 , 71 , 72 , 73 , 74 , 75 , 76 , 77 ]. The values of thermal conductivity of various fillers at room temperature are shown in Table 2 [ 50 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 ].…”

“…Polymers are widely used in electronic packaging, thermally conductive adhesives, and other fields because of their chemical stability, good insulation, and industrial production [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. However, most of the polymer materials are poor thermal conductors with low thermal conductivity, generally between 0.1–0.5 W·m −1 ·K − 1 , which greatly limits their wider applications [ 17 , 18 ].…”

Bifunctional Liquid Metals Allow Electrical Insulating Phase Change Materials to Dual-Mode Thermal Manage the Li-Ion Batteries

“…Previous PCMs were usually prepared by incorporating thermo-conductive fillers into the PCM matrix, paying tremendous attention to the k enhancement [ 20 – 23 ]. For example, the methods including the construction of an interconnected filler network, the orientation of anisotropic filler, and the interfacial enhancement between filler and matrix were adopted to improve the k of PCMs [ 24 – 36 ]. However, k determines the thermal conduction rate within a PCM in one specific direction; in addition to k , the thermal conduction directions and paths are identically important.…”