Thermal conductive graphite paper vs graphite sheet: Don't treat them as the same thing anymore

The core value of thermal conductive graphite paper is not to "take away the tropics", but to spread out the hotspots:

• In plane thermal conductivity: natural graphite 150-600 W/m · K, high conductivity natural 1000-1500 W/m · K, synthetic/PGS 700-1900 W/m · K
• Vertical thermal conductivity: typically 5-15 W/m · K
• Features: ultra-thin, lightweight, flexible, can fit curved surfaces, does not occupy Z-direction space

Typical Applications

• Mobile phones/tablets/laptops: SoC and RF modules are both hot
• LED driver, 5G base station, server network card
• The surface of the battery module is uniformly heated
• Electric bed/tatami: 0.1-0.2 mm natural graphite foil+silicone PSA as the soaking layer
• Power module: combination of graphite paper and thermal pad, not separated across gaps

Graphite flakes are in terminal form and can be classified into three categories based on their usage:

1.Thermal Graphite Sheet

• 0.1-0.5 mm is common
• Can be coated with single/double-sided PSA, PET/PI film, copper sandwich
• Used for electronic assembly, LED lighting fixtures, electric heating appliances, automotive ECU

2.Gasket / Sealing Sheet

• 0.5–3 mm
• Check compression rate, rebound rate, ash content, sulfur and chlorine content
• Flanges, valves, pump covers, heat exchangers, RTO equipment
• Can composite 316L punched mesh, 304 foil, fiberglass

3.Thermal Insulation/High Temperature Resistant Graphite Sheet

• Furnace door lining, electric heating bed backing, industrial kiln
• 450 ℃ in the air for a long time, with an inertia of up to 3000 ℃
• Composite metal foil is commonly used in high-temperature open environments to prevent oxidation

1.Different thickness logic

• Thermal conductive graphite paper: The thinner it is, the more suitable it is for electronic homogenization (0.03/0.05/0.1 mm)
• Graphite sheet: thicker to fill joints, withstand pressure, and die cut without breaking

2.Different thermal conductivity directions

Anisotropy of graphite material:

• On the surface: High, responsible for "spreading heat"
• Vertical: Low, cannot be used as a thick thermal pad

3.Adhesive determines the upper limit

• Acrylic acid PSA: ≤ 80 ℃ long-term
• Silicone PSA: 180-200 ℃
• No glue+mechanical pressure: the most stable in high temperature scenarios

4.Insulation requirements

Pure graphite conducts electricity.
Electronic customers must have "thermal conductivity but no short circuit" → PI/PET coating or dielectric coating is required.

5.Quotation caliber varies

• Graphite paper: reported by ㎡/kg/roll
• Graphite sheets: reported by sheet/die cut/specification size