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Industry Development Overview
With the rapid advancement of new energy vehicles and energy storage industries, power battery energy density continues to increase. The widespread adoption of fast-charging technology has significantly elevated charging current intensity, imposing increasingly stringent demands on thermal management systems. High-temperature environments not only degrade battery performance and cycle life but also pose safety hazards such as thermal runaway. Concurrently, surging demands for chip computing power in consumer electronics, 5G communications, artificial intelligence, and autonomous driving—coupled with increasing integration and assembly density of electronic components—have driven exponential growth in device power consumption and heat generation. Thermal management in electronics has thus become a critical bottleneck constraining technological advancement.
Research indicates that the failure rate of electronic components is positively correlated with operating temperature. For every 10°C increase in temperature, the device failure rate approximately doubles. This characteristic underscores the core value of thermal interface materials in thermal management for power batteries, energy storage systems, and electronic products.
Thermal management technology primarily relies on three physical mechanisms: thermal conduction, thermal convection, and thermal radiation. Among these, thermal conduction and thermal convection are the main approaches in current heat dissipation system design. Thermal conduction transfers heat generated by components to heat sinks via thermal media, ensuring stable operation within optimal temperature ranges. Thermal convection facilitates heat exchange through fluid movement (air or liquid), categorized into natural and forced convection. The latter often requires high-thermal-conductivity materials to enhance cooling efficiency.
Based on chemical composition, thermal interface materials (TIMs) can be categorized into polymer composites, metallic materials, carbon materials, and phase change materials. Among these, polymer composite TIMs dominate the market due to their high thermal conductivity, excellent electrical insulation, favorable processability, and cost-effective structure.
These materials utilize polymeric matrices such as silicone or epoxy resins, incorporating high-thermal-conductivity powders to establish thermal pathways. Common product forms include thermal silicone gel, thermal pads, and thermal grease. The type, loading amount, particle size distribution, morphology, and dispersion state of the thermal powder directly influence the final performance of the composite material. Optimizing powder selection, enhancing powder quality, designing a reasonable particle size distribution scheme, and implementing surface modification treatments have become key technical approaches to improving the thermal conductivity of composite materials. Ideal thermal conductive powders should exhibit comprehensive properties including high thermal conductivity, high density, high purity, good sphericity, and excellent dispersibility.
Industry Technical Characteristics
Thermal conductive powders used in polymer composite thermal management materials can be categorized into three major types based on chemical composition: metallic powders, carbon powders, and inorganic non-metallic powders. While metal powders and carbon materials inherently possess high thermal conductivity that significantly enhances composite thermal performance, their high electrical conductivity compromises material insulation properties, limiting their application in electronic and electrical equipment. Additionally, carbon materials like carbon nanotubes and graphene tend to agglomerate within polymer matrices, hindering the formation of continuous, efficient thermal conduction networks.
In contrast, inorganic non-metallic powders like oxides, carbides, and nitrides combine excellent thermal conductivity with insulating properties, demonstrating significant advantages in the preparation of high-thermal-conductivity insulating composites. Materials such as aluminum oxide, aluminum nitride, and boron nitride have become mainstream choices in the thermal powder market. Continuous optimization of their surface modification techniques and dispersion processes drives ongoing improvements in composite material performance.
Factors Affecting Thermal Conductive Material Performance
The performance of thermal conductive materials is influenced by multiple factors:
Regarding powder loading, at low loading levels, powder particles are fully encapsulated by the polymer matrix, making it difficult to form effective contact. This results in high thermal resistance and limited improvement in thermal conductivity. Once the loading reaches a critical value, a network or chain-like thermal conduction network forms between the powders, significantly enhancing thermal conductivity. While excessive filling may further enhance thermal conductivity, it causes a sharp increase in system viscosity and deteriorates processability.
Powder surface morphology significantly impacts material performance. Spherical powders, with their smaller interstitial spaces and higher packing density—especially when employing multi-size grading—can substantially improve the efficiency of thermal pathway formation. Simultaneously, spherical powders exhibit good flowability and minimal impact on system viscosity, facilitating improved processing techniques. Currently, only a few materials like alumina and silica can achieve large-scale spheroidization. Materials such as boron nitride and aluminum nitride are prone to oxidation during spheroidization, while aluminum hydroxide cannot be spheroidized due to its material properties.
The distribution state of powders directly determines the efficiency of thermal conduction network formation. Uniformly distributed powders more readily form highly efficient thermal conduction structures. Due to poor compatibility between inorganic powders and polymer matrices, agglomeration frequently occurs, creating voids at interfaces that increase thermal resistance. Surface modification treatments can significantly improve powder-matrix interface compatibility, enhance filling rates, and reduce system viscosity.
Powder particle size design must adhere to scientific proportioning principles. Theoretically, larger particles facilitate thermal pathways, while smaller particles exhibit higher thermal resistance due to increased contact area and complex heat transfer paths. Practical applications demonstrate that at low fill levels, smaller particle systems yield lower thermal conductivities than larger particle systems. However, beyond a threshold fill level, smaller particle systems exhibit more pronounced thermal conductivity increases. Therefore, rationally combining powders of different particle sizes to construct multidimensional thermal conduction networks has become a key technological approach for enhancing composite material performance.
Industry Development Trends
In the new energy vehicle sector, thermal interface materials for power batteries typically require thermal conductivities within the range of 0.4–2 W/(m·K), with thermal pads being the predominant product form. Mainstream fillers include spherical alumina and aluminum hydroxide, the latter offering both thermal conductivity and flame retardancy. Downstream manufacturers must strike an optimal balance between thermal performance and cost control. In automotive electronics, core components like motors and electronic control units demand thermal conductivities of 2–5 W/(m·K), a requirement set to rise further with the proliferation of fast-charging technology. High-insulation scenarios favor boron nitride fillers, with some automotive electronics requirements converging toward consumer electronics standards.
In network communications, applications like 5G copper-clad laminates and data center equipment demand materials with low dielectric properties and high thermal conductivity. Switching equipment and base stations require thermal conductivities exceeding 12 W/(m·K) as bandwidth increases. Spherical alumina and aluminum nitride blends dominate high-thermal-conductivity scenarios, while boron nitride fillers are preferred for high-insulation, high-frequency applications.
In consumer electronics, thermal management solutions typically employ multi-material strategies. As device power consumption increases and miniaturization advances, thermal conductivity requirements have risen above 12 W/(m·K). Spherical alumina serves as the primary filler in this sector, while high-end products increasingly incorporate nitride powders to enhance performance.
Overall, the thermal interface material industry is rapidly advancing toward high performance, multifunctionality, and cost reduction. Innovations in new materials, process optimization, and expanded application scenarios will continue driving technological progress, delivering more comprehensive thermal management solutions for industries including new energy vehicles, communication equipment, and consumer electronics.
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