In modern electronics and power systems — from industrial drives to aerospace modules — thermal management is a mission-critical challenge. Devices generate heat, and if that heat isn’t effectively transferred away, performance, reliability, and lifespan can suffer. But in many cases you also need electrical insulation between components and heat sinks or chassis. That’s where specialized thermally conductive electrical insulator pads come into play.
One advanced material widely used for this purpose is CHO-THERM T500. It’s engineered to provide a strong balance of thermal conduction, electrical insulation, and mechanical durability.
What Is CHO-THERM T500?
CHO-THERM T500 is a fiberglass-reinforced, silicone-based thermal interface pad designed to move heat efficiently from power components to a heat sink while maintaining high dielectric strength. It replaces older methods such as greased mica or silicone grease, offering cleaner installation and long-term stability.
Key performance highlights:
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Thermal Conductivity: ~2.1 W/m·K
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Thermal Impedance (at recommended pressure): ~0.19 °C-in²/W
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Standard Thickness: 0.010 in (0.25 mm)
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Operating Temperature Range: –60 °C to +200 °C
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Dielectric Strength: up to ~4,000 Vac
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Reinforcement: Fiberglass for tear resistance and dimensional stability
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Flammability Rating: UL V-0
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Low Outgassing: Suitable for aerospace and sensitive environments
- Color Green
The pad is also available with or without a pressure-sensitive adhesive (PSA) backing for easier assembly.
Where It’s Used
CHO-THERM T500 is especially valuable when you need high thermal transfer and electrical insulation in one material, plus mechanical strength for assembly and long-term reliability.
Typical applications include:
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Power conversion modules and inverters
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IGBTs, MOSFETs, and other power semiconductors
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UPS systems and industrial drives
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Automotive electronics and motor controllers
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Aerospace, military, and avionics systems
Because it’s robust and consistent, it’s often chosen in mission-critical and high-power density designs.
Advantages and Considerations
Advantages
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Stable Interface: No grease migration, no reapplication needed.
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Efficient Heat Transfer: Low thermal impedance and good conductivity.
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Electrical Isolation: High dielectric strength for safety and performance.
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Mechanical Strength: Fiberglass reinforcement resists puncture and tear.
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Wide Temperature Range & Reliability: Performs across extreme conditions with low outgassing.
Considerations
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Pads require good surface flatness and consistent clamping to achieve best thermal performance.
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The adhesive option, while convenient, can add slight extra thermal resistance.
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Ultra-high power density designs may still require more exotic materials or direct-bonded interfaces.
Application Tips
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Keep contact surfaces clean, flat, and smooth to maximize heat transfer.
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Use recommended clamping pressure to reduce air gaps.
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Place the PSA side for easier assembly, not on the most thermally demanding face if minimal resistance is critical.
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For aerospace or vacuum applications, confirm outgassing specifications meet mission needs.
Nomenclature:
69-12-20036-T500 (17” x 21” sheet, PSA one side)
69-11-20035-T500 (17” x 21” sheet, no PSA)
The Bottom Line
CHO-THERM T500 is a proven, high-performance solution where thermal conductivity, electrical insulation, and mechanical integrity must work together. It’s ideal for power electronics, automotive, aerospace, and industrial designs where you want reliability and predictable long-term performance without the mess or maintenance of greases or pastes. NEDC does custom die cutting, laser cutting, knife-cutting, and many other forms of conversation thermal pads such as Cho-Therm T500.