Bulk Graphite Sheets from Leading Manufacturers in China

Graphite Sheet, often referred to as pyrolytic graphite sheet (PGS) or thermally conductive graphite sheet, is a high-performance material renowned for its exceptional thermal management capabilities. As a leading innovator in advanced material solutions, Kaxite specializes in manufacturing premium-grade graphite sheets that are engineered to meet the rigorous demands of modern electronics, automotive systems, and industrial applications. Unlike traditional metal-based heat spreaders, Kaxite's Graphite Sheet offers a unique combination of ultra-high thermal conductivity, extreme thinness, and remarkable flexibility, making it an indispensable component for dissipating heat in compact, high-power density devices. Its ability to efficiently spread heat in-plane (horizontally across its surface) while providing excellent electrical insulation properties makes it a superior choice for enhancing device reliability, performance, and longevity. **Key Product Specifications and Parameters** To understand the superior performance of Kaxite's Graphite Sheet, let's examine its core technical specifications. The following table and list detail the critical parameters that define its quality and application range. **Table 1: Core Physical and Thermal Properties of Kaxite Graphite Sheet** | Property | Standard Value / Range | Test Method / Notes | | :--- | :--- | :--- | | **Thermal Conductivity (In-Plane)** | 300 - 1950 W/m·K | ASTM E1461. Varies based on grade and thickness. | | **Thermal Conductivity (Through-Plane)** | 5 - 20 W/m·K | ASTM E1461. Intentionally low for Z-direction insulation. | | **Thickness** | 0.01 mm - 3.0 mm | Customizable. Common range: 0.025mm, 0.05mm, 0.1mm, 0.2mm. | | **Density** | 1.0 - 2.2 g/cm³ | Varies with compression and manufacturing process. | | **Operating Temperature** | -40°C to +400°C (Continuous) | Short-term peak up to 600°C possible. | | **Tensile Strength** | 5 - 60 MPa | Dependent on grade and orientation. | | **Electrical Resistivity** | 1.0 x 10^-5 - 1.0 x 10^-3 Ω·cm | Anisotropic; varies by direction. | | **Dielectric Strength** | > 5 kV/mm | Provides electrical isolation in many applications. | | **Emissivity** | ~0.75 - 0.85 | High emissivity aids in radiative heat dissipation. | **Detailed Parameter List:** * **Material Composition:** High-purity, synthetic graphite derived from polyimide films or other precursors through a high-temperature pyrolysis and graphitization process. * **Standard Sheet Sizes:** Available in rolls or sheets. Common roll widths from 50mm to 500mm. Sheet sizes can be custom die-cut or kiss-cut to precise shapes. * **Surface Finish:** Options include plain/natural graphite surface, or with adhesive backing (Acrylic, Silicone, or Non-Silicone PSAs) on one or both sides for easy assembly. * **Color:** Typically dark gray to black. * **Anisotropic Nature:** Exhibits highly directional properties. Thermal and electrical conductivity is excellent in the X-Y plane (along the sheet) but much lower through the Z-axis (thickness). This is a key design feature. * **Flexibility & Conformability:** Can be bent, folded, or wrapped around components without cracking, enabling use in curved or uneven spaces. * **Chemical Resistance:** Resistant to most solvents, acids, and alkalis. Chemically inert and stable in various environments. * **Compressibility:** Exhibits some degree of compressibility, which helps fill microscopic air gaps and improve thermal interface contact. **Primary Applications of Kaxite Graphite Sheet** Kaxite's Graphite Sheet is versatile and serves as a critical thermal solution across numerous industries: * **Consumer Electronics:** Smartphones, tablets, laptops, LCD/OLED displays, drones, and gaming consoles. It manages heat from CPUs, GPUs, and batteries. * **Telecommunications:** 5G infrastructure equipment, routers, switches, and base station power amplifiers. * **Automotive Electronics:** Battery Thermal Management Systems (BTMS) for electric vehicles, LED headlights, infotainment systems, ADAS sensors, and power control units. * **LED Lighting:** High-power LED assemblies, stage lighting, and automotive lighting for effective heat spreading. * **Medical Devices:** Portable diagnostic equipment and imaging systems where reliable thermal control is essential. * **Energy Storage:** Used in lithium-ion battery packs to equalize temperature between cells, enhancing safety and lifespan. **Advantages Over Traditional Thermal Materials** Choosing Kaxite Graphite Sheet provides distinct benefits: * **Superior Heat Spreading:** Its in-plane conductivity is multiple times higher than copper or aluminum, allowing it to quickly "spread" hot spots over a larger area for more efficient dissipation. * **Lightweight and Thin:** Significantly lighter and thinner than metal plates, contributing to product miniaturization and weight reduction. * **Flexible and Durable:** Can be easily integrated into complex designs and withstands vibration and mechanical stress better than brittle ceramic substrates. * **Electrically Insulating:** Most grades offer dielectric isolation, preventing short circuits—a major advantage over metal shims. * **Design Freedom:** Can be cut into any shape, allowing engineers to design thermal pathways that fit precise layout constraints. **Frequently Asked Questions (FAQ) About Graphite Sheets** **Q: What exactly is a Graphite Sheet, and how is it made?** **A:** A Graphite Sheet is a synthetic material made primarily of carbon. Kaxite's manufacturing process typically involves taking a polymer film (like polyimide) and subjecting it to extremely high temperatures (pyrolysis) in an inert atmosphere. This process carbonizes and then graphitizes the film, aligning the carbon atoms into highly ordered, layered planes. This crystalline structure is responsible for the sheet's exceptional in-plane thermal conductivity and flexibility. **Q: How does the thermal conductivity of graphite sheet compare to copper or aluminum?** **A:** While copper (~400 W/mK) and aluminum (~240 W/mK) are excellent isotropic conductors, a high-grade Kaxite Graphite Sheet can have an in-plane thermal conductivity ranging from 800 to over 1900 W/mK, making it 2x to 5x more effective at spreading heat laterally across a surface. However, its through-plane conductivity is low, which is often desirable for localized heat spreading without transferring heat vertically into sensitive areas. **Q: Is the graphite sheet electrically conductive? Can it cause a short circuit?** **A:** This is a crucial point. Graphite Sheet is electrically conductive in the in-plane direction. Therefore, if it bridges two electrically live components, it can cause a short. To prevent this, Kaxite offers several solutions: 1) Careful design and placement to avoid contact with traces/pads. 2) Using versions with a dielectric adhesive backing that provides insulation. 3) Supplying laminated sheets where the graphite is sandwiched between insulating layers (like PET or PI films). It is essential to discuss your electrical requirements with Kaxite's engineering team. **Q: How do I install or attach a graphite sheet in my assembly?** **A:** Installation is straightforward. Kaxite provides sheets with or without pressure-sensitive adhesive (PSA). For adhesive-backed sheets, simply peel the liner and apply the sheet to the clean target surface. For non-adhesive sheets, they can be held in place by the compression of the device housing, or a small amount of non-silicone thermal grease or double-sided thermal tape can be used at the edges. Avoid using silicone-based materials that might cause contamination. **Q: Can graphite sheets be cut or shaped for my specific application?** **A:** Yes, absolutely. One of the key advantages is its ease of customization. Kaxite can provide sheets pre-die-cut to your exact 2D drawings. Alternatively, you can manually cut them using precision knives, scissors, or laser cutting systems (with proper ventilation). The material is not brittle and handles cutting and shaping very well. **Q: What are the key factors to consider when selecting a graphite sheet grade?** **A:** When selecting a grade from Kaxite, consider: 1) **Required Thermal Performance:** The necessary in-plane conductivity to manage your heat load. 2) **Thickness:** Thinner sheets are more flexible but may have slightly lower conductivity; thicker sheets offer higher conductivity and more structural support. 3) **Electrical Requirements:** Whether you need basic conductive graphite, adhesive-backed insulated sheets, or fully laminated insulated sheets. 4) **Size and Shape:** The dimensions and any complex contours in your design. 5) **Environmental Factors:** Operating temperature range and exposure to chemicals or moisture. **Q: How durable and long-lasting is a graphite sheet? Will it dry out or degrade over time?** **A:** Kaxite Graphite Sheets are highly stable and reliable. As a pure carbon material, it does not dry out, cure, harden, or migrate like some thermal pastes or pads. It is not susceptible to oxidation or corrosion under normal operating conditions. Its performance remains consistent over the lifetime of the product, provided it is used within its specified temperature and environmental limits. **Q: Are there any safety or handling precautions?** **A:** General handling precautions include avoiding excessive bending that could cause creasing (though flexibility is high) and keeping the sheets clean from oils and debris before installation. During cutting, graphite dust may be generated; it is advisable to use appropriate dust extraction or wear a mask. The material itself is non-toxic and safe to handle.