SpreaderShield™ SS350
SpreaderShield™ SS350 is a natural graphite flexible heat spreader and heat shield with an in-plane thermal conductivity of 350 W/m·K and a through-plane thermal conductivity of 4.1 W/m·K, available in thicknesses from 0.127 to 0.94 mm. It delivers a thermal contact impedance of 0.34 °C·cm²/W per side at 0.51 mm, an in-plane electrical conductivity of 1,750 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: 350 W/m·K
- Thermal Conductivity — Through-Plane: 4.1 W/m·K
- Thermal Contact Impedance Per Side: 0.34 °C·cm²/W @ 0.51 mm thickness
- Operating Temperature Range: -40°C to +400°C
- Thickness Capability Range: 0.127 – 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 | 0.127 – 0.94 mm | — |
| Typical Roll Thickness • Width | 0.94 • 610 mm, 0.48 • 610 mm, 0.20 • 610 mm | — |
Thermal Properties
| Property | Value | Test Method |
| Thermal Conductivity — In-Plane | 350 W/m·K | Neograf Standard Method |
| Thermal Conductivity — Through-Plane | 4.1 W/m·K | ASTM D5470 Modified |
| Thermal Contact Impedance Per Side | 0.34 °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 | 5.8 µΩ·m | — |
| Electrical Conductivity — In-Plane | 1,750 S/cm | — |
| Electrical Conductivity — Through-Plane | 23 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 to distribute localized heat sources across larger surface areas
- 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™ SS350 is the entry thermal conductivity grade in the SpreaderShield™ natural graphite flexible heat spreader product line, delivering 350 W/m·K in-plane thermal conductivity. It functions simultaneously as a passive heat spreader — laterally distributing heat from a localized source across a larger surface area — and as a heat shield.
The flexible graphite construction can be die-cut or laminated with plastics and/or adhesives, and is available with plastic and adhesive coating options. Typical roll configurations are 0.94 mm × 610 mm, 0.48 mm × 610 mm, and 0.20 mm × 610 mm width.
The material exhibits 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 5.8 µΩ·m. Through-plane electrical conductivity is 23 S/cm. No tensile strength value is listed on the TDS for SS350.
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 SS350 from SS400, SS500, and SS600?
SS350 is the entry in-plane thermal conductivity grade in the SpreaderShield™ natural graphite series at 350 W/m·K, with the highest through-plane thermal conductivity in the group at 4.1 W/m·K. SS400, SS500, and SS600 step up in in-plane conductivity (400, 500, and 600 W/m·K respectively) but carry lower through-plane conductivities (3.7, 2.8, and 3.5 W/m·K). SS350 also has the broadest thickness capability range (0.127–0.94 mm) alongside SS400. No tensile strength is listed on the TDS for SS350.
Why does in-plane thermal conductivity matter for heat spreader selection?
In-plane thermal conductivity determines how efficiently SpreaderShield™ SS350 laterally distributes heat from a localized source — such as a chip or LED — across the spreader area. Higher in-plane conductivity reduces the peak temperature at the heat source by spreading the thermal load over a larger area before it reaches the heat sink. At 350 W/m·K, SS350 provides effective lateral heat distribution for moderate heat flux applications.
What is the operating temperature range for SS350?
The operating temperature range for SS350 is –40°C to +400°C as listed on the TDS.
Is SS350 suitable for flame-rated environments?
Yes. SS350 carries a UL 94V-0 flammability rating and is RoHS compliant, lead-free, and halogen-free.
How should SS350 be specified?
Specify grade (SpreaderShield™ SS350), thickness, coating options (plastic lamination, adhesive type), compliance requirements, dimensional tolerances, and finished format.
