SpreaderShield™ SS400
SpreaderShield™ SS400 is a natural graphite flexible heat spreader and heat shield with an in-plane thermal conductivity of 400 W/m·K and a through-plane thermal conductivity of 3.7 W/m·K, available in thicknesses from 0.050 to 0.94 mm — the broadest thickness range in the natural graphite series. It delivers a thermal contact impedance of 0.38 °C·cm²/W per side at 0.51 mm, a tensile strength of 9.7 MPa, an in-plane electrical conductivity of 1,900 S/cm, and an operating temperature range of -40°C to +400°C. The material is UL 94V-0 rated and RoHS compliant.
Key Properties
- Thermal Conductivity — In-Plane: 400 W/m·K
- Thermal Conductivity — Through-Plane: 3.7 W/m·K
- Thermal Contact Impedance Per Side: 0.38 °C·cm²/W @ 0.51 mm thickness
- Operating Temperature Range: -40°C to +400°C
- Thickness Capability Range: 0.050 – 0.94 mm
- UL Flammability Rating: 94V-0
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Thickness Capability Range | 0.050 – 0.94 mm | — |
| Typical Roll Thickness • Width | 0.94 • 610 mm, 0.51 • 584 mm, 0.25 • 584 mm, 0.127 • 610 mm, 0.050 • 355 mm | — |
| Tensile Strength | 9.7 MPa | — |
Thermal Properties
| Property | Value | Test Method |
| Thermal Conductivity — In-Plane | 400 W/m·K | Neograf Standard Method |
| Thermal Conductivity — Through-Plane | 3.7 W/m·K | ASTM D5470 Modified |
| Thermal Contact Impedance Per Side | 0.38 °C·cm²/W @ 0.51 mm | — |
| Coefficient of Thermal Expansion — In-Plane | –0.4 ppm/°C | — |
| Coefficient of Thermal Expansion — Through-Plane | 27.0 ppm/°C | — |
| Specific Heat @ 50°C | 0.81 J/g·°C | Quasi-Isothermal Modulated DSC |
| Operating Temperature Range | –40°C to +400°C | — |
Electrical Properties
| Property | Value | Test Method |
| Electrical Resistivity — In-Plane | 5.2 µΩ·m | — |
| Electrical Conductivity — In-Plane | 1,900 S/cm | — |
| Electrical Conductivity — Through-Plane | 18 S/cm | — |
Flame & Fire Performance
| Property | Value | Test Method |
| UL Flammability Rating | 94V-0 | — |
Regulatory / Compliance Data
| Property | Value | Test Method |
| RoHS Compliant | Yes | — |
| Lead / Halogen-Free | Yes | — |
Compliance
- UL 94V-0 — Compliant
- RoHS — Compliant
- Lead / Halogen-Free — Yes
- Passive heat spreading in consumer and industrial electronics requiring a wide range of available thicknesses from ultra-thin to standard gauge
- Heat shielding in thermal management assemblies requiring a flexible, conformable graphite layer
- Die-cut thermal management components for LED lighting, displays, and portable electronics
- Laminated graphite assemblies with plastic or adhesive coatings for protection and ease of installation
- Thermal management in battery and power electronics assemblies operating across –40°C to +400°C
Common industries: Electronics, LED lighting, consumer devices, automotive, telecommunications, thermal management systems.
SpreaderShield™ SS400 is the second grade in the SpreaderShield™ natural graphite flexible heat spreader series, delivering 400 W/m·K in-plane thermal conductivity while offering the widest thickness capability range in the natural graphite lineup — from 0.050 mm to 0.94 mm. It functions simultaneously as a passive heat spreader and heat shield, and the flexible graphite construction can be die-cut or laminated with plastics and/or adhesives.
Typical roll configurations include 0.94 mm × 610 mm, 0.51 mm × 584 mm, 0.25 mm × 584 mm, 0.127 mm × 610 mm, and 0.050 mm × 355 mm, providing the greatest number of standard roll options in the series.
The material achieves a tensile strength of 9.7 MPa, a coefficient of thermal expansion of –0.4 ppm/°C in-plane and 27.0 ppm/°C through-plane, a specific heat of 0.81 J/g·°C at 50°C, and an in-plane electrical resistivity of 5.2 µΩ·m. Through-plane electrical conductivity is 18 S/cm. In-plane thermal conductivity is determined by Neograf Standard Method; through-plane thermal conductivity is determined by ASTM D5470 Modified method.
Properties listed are typical and cannot be used as acceptance or rejection criteria; product characteristics exclude coatings and adhesives.
Compliant with UL 94V-0, RoHS; lead and halogen-free.
What differentiates SS400 from SS350, SS500, and SS600?
SS400 offers the widest thickness capability range in the natural graphite series (0.050–0.94 mm) and the greatest number of standard roll configurations, making it the most versatile grade for applications spanning ultra-thin to thicker constructions. Its in-plane conductivity of 400 W/m·K sits between SS350 (350 W/m·K) and SS500 (500 W/m·K). Through-plane conductivity is 3.7 W/m·K versus 4.1 for SS350, 2.8 for SS500, and 3.5 for SS600.
Why does in-plane thermal conductivity matter for heat spreader selection?
In-plane thermal conductivity determines how efficiently SpreaderShield™ SS400 laterally distributes heat from a localized source across the spreader area. At 400 W/m·K — nearly twice that of copper's through-plane conductivity — SS400 can spread heat from high-flux sources such as power LEDs or processors across a significantly larger effective radiating surface, reducing peak component temperatures.
What is the operating temperature range for SS400?
The operating temperature range for SS400 is –40°C to +400°C as listed on the TDS.
Is SS400 suitable for flame-rated environments?
Yes. SS400 carries a UL 94V-0 flammability rating and is RoHS compliant, lead-free, and halogen-free.
How should SS400 be specified?
Specify grade (SpreaderShield™ SS400), thickness, coating options (plastic lamination, adhesive type), compliance requirements, dimensional tolerances, and finished format.
