When engineers need a thermal interface material that is electrically isolating, durable, and consistent under mechanical stress, Bergquist Sil-Pad® 1200 aka SIL PAD TSP 1800 is one of the most trusted options on the market. It’s a silicone-based, fiberglass-reinforced pad designed specifically for mounting power devices to heat sinks—where thermal transfer, electrical insulation, and mechanical robustness all intersect.
At NEDC, we convert Sil-Pad 1200 aka SIL PAD TSP 1800 into custom die-cut shapes, sheets, and roll formats so device manufacturers can drop these pads directly into assembly.
What is Sil-Pad 1200 aka TSP 1800?
Sil-Pad 1200 is a thermally conductive elastomeric material, built from:
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Silicone rubber — provides flexibility, temperature resistance, electrical insulation
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Fiberglass carrier — gives reinforcement, dimensional stability, and cut-through resistance
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Smooth, non-tacky surfaces — makes re-positioning and assembly easier
This architecture creates a pad that is compliant enough to “wet out” on surfaces but strong enough for screw-mounted or clip-mounted power devices. Performance improves dramatically with more pressure on any of the Sil-Pad options.
Key Material Properties
Thermal
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Thermal conductivity: 1.8 W/m-K
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Thermal impedance @ 50 psi: 0.53 °C-in²/W
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Excellent performance at both low and high mounting pressures
Electrical
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Dielectric breakdown voltage: 6000 Vac
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Dielectric constant: 8.0
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Volume resistivity: 10⁹ ohm-meter
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UL 94 V-0 flame rating
Mechanical
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Thickness range: 0.009–0.016 in. (9, 12, or 16 mils)
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Hardness: Shore 00 = 80
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Tensile strength: 1300 psi
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Elongation: 20%
Temperature Capability
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Continuous use temp: –76°F to +356°F (–60°C to +180°C)
Why Engineers Use Sil-Pad 1200
1. Strong thermal performance at low pressure
Many pads require high compression to achieve good thermal impedance. Sil-Pad 1200 performs exceptionally well even at 10–25 psi and continues to improve as pressure rises.
2. High electrical insulation
A breakdown voltage of 6000 Vac ensures safe isolation between power semiconductors and heat sinks.
3. Dimensional stability + cut-through resistance
The fiberglass reinforcement makes it ideal for:
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Screw-mounted transistor packages
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Clip-mounted power devices
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Harsh vibration or thermal cycling environments
4. Easy to assemble
The smooth, non-tacky surfaces reduce alignment errors and allow technicians to reposition the pad before final mounting. Keep in mind the PSA added (AC) can make placement a little bit more difficult. In addition, PSA can reduce thermal performance slightly.
5. Ideal for custom die-cutting
NEDC routinely converts Sil-Pad 1200 into:
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Pre-punched transistor pads
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Assembly kits
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Sheets or narrow roll widths
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Adhesive-backed versions
Typical Applications
Sil-Pad 1200 is commonly used in:
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Automotive power electronics
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Motor drives
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Power supplies
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Discrete power semiconductors
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Audio amplifiers
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Inverters, rectifiers, and regulators
Whenever a power device must be mounted to a heat sink with electrical isolation, Sil-Pad 1200 is a reliable choice.
Available Formats
Sil-Pad 1200 can be supplied as:
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Sheets (e.g., 12″ × 12″)/rolls
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Standard thicknesses: 9, 12, and 16 mil
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Die-cut parts
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Optional adhesive coating (“AC”) on one side for ease of application
A typical part number structure looks like:
SP1200 – 0.012 – 00 – 1212 (.012”, NO PSA), SP1200-0.016-AC-1212 (.016”, PSA ONE SIDE)
(12 mil, no adhesive, 12″ × 12″ sheet)
Why Sil-Pad 1200 Still Matters Today
Even with newer gap pads and phase-change materials on the market, Sil-Pad 1200 remains a go-to option for:
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Ruggedized assemblies
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Low-profile thermal joints
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Applications requiring high dielectric strength
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Cost-sensitive builds that still require reliability
It’s simple, dependable, and proven—exactly what power electronics engineers expect when long-term stability matters. For more information, please contact sales@nedc.com.