Graphite Sheet - High Thermal Conductivity & EMI Shielding

If you’ve ever chased hotspots in a thin device or fought thermal fade in a power module, you’ve probably landed on a graphite sheet at some point. I certainly have—more times than I can count. And lately, China’s “Thermal Conductive Graphite Paper” lines have been getting seriously competitive, both on performance and MOQ flexibility.

Origin note: this series ships out of Qiujing yiyuan, No. 189, East 2nd Ring North Road, Chang’an District, Shijiazhuang, Hebei. Not a glamorous address, but the output is tidy.

What’s trending (and why it matters)

- Foldables and ultra-slim laptops need anisotropic heat spreaders that flatten peaks without adding mass. graphite sheet hits that sweet spot.
- EV battery and BMS packs use it for planar heat spreading and as a layer in friction materials. To be honest, adoption here is moving faster than many predicted.
- LED and server OEMs are replacing copper foils to save weight while keeping skin temperatures in check.

Product snapshot: Thermal Conductive Graphite Paper in China

Application Areas: Electron industry, friction materials, heat conduction. Feature: high thermal conductivity. Customization: available (die-cut, adhesive, carrier films, odd shapes—yes, even those “banana” folds for hinge zones).

Property	Typical value (≈)	Test standard	Notes
In-plane thermal conductivity	800–1600 W/m·K	ASTM D5470 / ISO 22007-2	Real-world use may vary with stackup
Through-plane thermal conductivity	8–15 W/m·K	ASTM D5470	Highly anisotropic by design
Thickness	0.025–0.50 mm	Caliper	Custom gauges on request
Density	1.0–1.4 g/cm³	ASTM D792	Low mass vs. copper
Tensile strength	5–12 MPa	ASTM F152	Flexible but not indestructible
Temperature range	-40 to 400°C (air); up to 3000°C (inert)	—	Adhesives may limit rating

How it’s made (short version)

Natural flake graphite → chemical intercalation → rapid thermal expansion → calendering into graphite sheet → optional lamination with PET/PI/Al foils → PSA application → precision die-cut. QC typically runs thermal conductivity (D5470), EMI shielding (ASTM D4935), thickness/flatness, and 85/85 aging. Service life in electronics: around 5–10 years at 60–80°C, depending on humidity and adhesive system.

Where it’s used

- Phones, tablets, foldables (hotspot flattening under SoC/PMIC)
- Notebooks/VR headsets (weight-sensitive)
- LED modules, telecom base stations, servers
- EV battery, BMS, and—as a surprise to some—friction materials in braking systems Advantages: ultra-high in-plane k, low density, easy to die-cut, conforms to uneven surfaces. Watchouts: edge brittleness, conductive dust during converting, and the usual anisotropy (don’t expect miracles through thickness).

Vendor	In-plane k (≈)	Min thick	Certs	Lead time	Notes
NL Graphite (China)	1000–1600 W/m·K	0.025 mm	ISO 9001, RoHS, REACH	2–4 weeks	Strong on customization
Brand J (Japan)	1200–1700 W/m·K	0.020 mm	ISO 14001, RoHS	4–6 weeks	Premium pricing
Brand K (Korea)	900–1400 W/m·K	0.030 mm	RoHS, REACH	3–5 weeks	Good cost/performance

Customization and integration

- Die-cutting with ±0.1 mm tolerance, kiss-cut on liner
- PSA options: acrylic (UL 94 V-0 stack possible), silicone for rework
- Carriers: PET/PI/Al foils; anti-scratch films for assembly
- Pre-laminated thermal pads where a hybrid stack is needed

Field notes and quick case studies

- Smartphone OEM: swapping copper for graphite sheet reduced peak skin temperature by 12°C in a 5-minute 4K recording test; weight down ~18%.
- EV module: adding a 0.1 mm layer spread heat from FETs, dropping hotspot ΔT by ≈9°C; no penalty on pack mass budget. One Shenzhen ODM told us, “Install was painless—dust control mattered more than alignment.”

Compliance and test data

- Thermal: ASTM D5470 / ISO 22007-2 (laser flash) reports provided
- EMI shielding: 40–80 dB @ 1 MHz–10 GHz per ASTM D4935 (sample dependent)
- Environmental: RoHS (2011/65/EU), REACH (EC 1907/2006), ISO 9001; UL 94 V-0 achievable for certain laminated stacks
- Reliability: 85°C/85%RH 1000 h shrinkage graphite sheet from Hebei is a very sane default—especially if you need fast-turn customization.

Authoritative citations

1. ASTM D5470: Standard Test Method for Thermal Transmission Properties of Thermally Conductive Materials.
2. ISO 22007-2: Plastics — Determination of thermal conductivity and diffusivity — Part 2: Transient plane heat source method.
3. ASTM D4935: Standard Test Method for Measuring the Electromagnetic Shielding Effectiveness of Planar Materials.
4. EU RoHS Directive 2011/65/EU and REACH Regulation (EC) No 1907/2006.
5. UL 94: Tests for Flammability of Plastic Materials for Parts in Devices and Appliances.