Graphite sheet is a highly versatile and efficient thermal management material widely used across various industries. At Kaxite, we specialize in manufacturing premium-grade graphite sheets designed to meet the most demanding requirements for heat dissipation, EMI shielding, and component protection. Our products leverage the exceptional anisotropic thermal conductivity of natural or synthetic graphite, offering superior performance in a thin, flexible, and lightweight form factor.
Kaxite graphite sheets stand out due to our commitment to quality, consistency, and technical support. We control the manufacturing process from raw material selection to final lamination, ensuring every sheet delivers optimal thermal performance and reliability. Our materials are engineered for:
Selecting the right graphite sheet requires careful consideration of its technical specifications. Below, we detail the key parameters of Kaxite's standard graphite sheet offerings.
| Product Code | Thickness (mm) | Thermal Conductivity (W/m·K) In-Plane | Through-Plane Thermal Conductivity (W/m·K) | Density (g/cm³) | Standard Sheet Size (mm) | Primary Facing/Coating |
|---|---|---|---|---|---|---|
| KX-GS100 | 0.1 | 300 - 400 | 5 - 10 | 1.1 - 1.3 | 300 x 300 | Single-sided Polyimide (PI) |
| KX-GS150 | 0.15 | 400 - 600 | 5 - 10 | 1.2 - 1.4 | 300 x 300 | Single-sided PI |
| KX-GS200 | 0.2 | 600 - 800 | 6 - 12 | 1.3 - 1.5 | 300 x 300, 500 x 500 | Double-sided PI |
| KX-GS250 | 0.25 | 800 - 1000 | 6 - 15 | 1.4 - 1.6 | 500 x 500 | Double-sided PI |
| KX-GS300 | 0.3 | 1000 - 1500 | 8 - 20 | 1.5 - 1.8 | 500 x 500, 600 x 600 | Double-sided PI or PSA (Pressure Sensitive Adhesive) |
| KX-GS-EMI150 | 0.15 | 350 - 500 | 5 - 10 | 1.3 - 1.5 | 300 x 300 | Conductive Adhesive Layer |
Note: Custom thicknesses, sizes, thermal conductivities, and facings (like metal foil, silicone rubber) are available upon request. All data is typical and subject to standard manufacturing tolerances.
| Material | In-Plane Thermal Conductivity (W/m·K) | Flexibility | Weight | EMI Shielding | Typical Application |
|---|---|---|---|---|---|
| Kaxite Graphite Sheet | 300 - 1500+ | Excellent | Very Light | Good to Excellent | Smartphones, CPUs, LEDs, Batteries |
| Aluminum | ~200 (isotropic) | Poor (requires machining) | Heavy | Good | Heat Sinks, Enclosures |
| Copper | ~400 (isotropic) | Poor (requires machining) | Very Heavy | Excellent | High-power Heat Sinks |
| Thermal Grease/Pads | 1 - 10 (through-plane only) | Conformable | Light | None | Interface Filler |
| Standard PCB Substrate (FR4) | ~0.3 | Rigid | Light | Poor | Circuit Board Base |
The unique properties of graphite sheets make them indispensable in modern technology.
Q: What exactly is a graphite sheet and how does it work?
A: A graphite sheet is a thin, flexible material made from compressed exfoliated graphite. It works as a heat spreader due to its highly anisotropic structure. The carbon atoms are arranged in layers (planes) with very strong bonds within the plane, allowing heat to travel rapidly across the sheet's surface (in-plane). The bonds between the layers are weaker, meaning heat transfer through the thickness (through-plane) is much lower. This property makes it perfect for pulling heat away from a concentrated source (like a CPU) and spreading it over a larger area for more efficient dissipation into the air or a heat sink.
Q: How do I select the right thickness and thermal conductivity for my application?
A: Selection depends on your thermal budget, space constraints, and heat source profile. Thinner sheets (0.1-0.2mm) are ideal for ultra-thin devices like smartphones. They offer good spreading with minimal space. For higher heat fluxes, thicker sheets (0.25-0.3mm) with higher in-plane conductivity (800+ W/m·K) are better. Consider the total thermal resistance path: the sheet must have sufficient conductivity to move heat from the source to the dissipation area without creating a large temperature gradient. Kaxite's engineering team can assist with thermal modeling and selection.
Q: Can graphite sheets be cut and shaped easily?
A: Yes, one of the major advantages of graphite sheets from Kaxite is their excellent flexibility and ease of fabrication. They can be cleanly die-cut, laser-cut, or even hand-cut with sharp blades or scissors to fit specific shapes and contours. This allows for precise application around components, connectors, and curved surfaces without sacrificing performance.
Q: How do I install a graphite sheet? Does it require adhesive?
A: Installation methods vary. Many Kaxite graphite sheets come with a Polyimide (PI) film facing for electrical insulation and handling. These can be attached using a thin layer of non-silicone thermal grease or a thermally conductive pressure-sensitive adhesive (PSA) tape. We also offer sheets with a pre-applied PSA layer (like our KX-GS300-PSA variant) for easy, clean, and direct application. Ensure the surfaces are clean and free of debris for optimal thermal contact.
Q: Are graphite sheets electrically conductive? Is insulation needed?
A: Yes, pure graphite sheets are electrically conductive in the in-plane direction. This is actually beneficial for EMI shielding applications. However, for thermal management where the sheet may contact live electrical components, electrical insulation is crucial to prevent short circuits. This is why Kaxite typically laminates sheets with a dielectric polyimide film (PI tape), which provides excellent electrical isolation while having minimal impact on through-plane thermal resistance.
Q: How durable and long-lasting are graphite sheets?
A: Kaxite graphite sheets are chemically inert and highly stable. They do not dry out, pump out, or degrade like some phase-change materials or greases. They are resistant to moisture and most chemicals. With proper installation (protected from abrasive physical damage), they will maintain their thermal performance for the entire lifespan of the device, making them a highly reliable solution.
Q: Can graphite sheets replace traditional heat sinks or heat pipes?
A: They often complement or replace small heat sinks. In space-constrained applications (like smartphones), a graphite sheet is frequently the primary heat spreading solution. For very high-power applications, graphite sheets are used as an intermediate heat spreader between the chip and a larger aluminum or copper heat sink or heat pipe, improving the overall system efficiency by eliminating hot spots. They are not typically a direct replacement for large, finned heat sinks in high-power convection-cooled systems but are a key component within them.
Q: Does Kaxite offer custom-sized or shaped graphite sheets?
A: Absolutely. While we provide standard sheet sizes, a significant portion of our business is supplying custom die-cut or kiss-cut parts. You can provide us with a CAD drawing, and we will manufacture the graphite sheets in the exact shape, size, and with specific facings or adhesives required for your assembly process. This reduces waste and simplifies integration for our clients.
Q: What about EMI shielding? How effective are graphite sheets?
A: Graphite sheets provide excellent EMI shielding effectiveness (SE), particularly in the higher frequency ranges (GHz). Their conductivity allows them to absorb and reflect electromagnetic waves. For dedicated EMI shielding applications, Kaxite offers variants like KX-GS-EMI150, which may include conductive adhesives for grounding to chassis, creating a continuous shielded enclosure. The SE value depends on thickness, density, and contact resistance.
