SilCool™ TIA208R: High-Voltage Potting & Dielectric Silicone Encapsulant

SilCool TIA208R is a 2-component, thermally conductive silicone encapsulant engineered to meet the rigorous demands of high-voltage (HV) electronics. While it delivers excellent thermal management (0.7 W/m·K), its primary advantage for HV designers lies in its exceptional dielectric insulation and robust, primerless adhesion. It is the material of choice for OEM high-voltage power supply manufacturers, developers of medical X-ray systems, and engineers working on precision test and measurement equipment who require reliable insulation alongside thermal dissipation. Unique among potting compounds, TIA208R provides primerless adhesion to both metallic substrates and difficult-to-bond plastics (such as Polycarbonate). This capability is critical in HV assemblies, where eliminating a primer step reduces process variability and the risk of partial discharge due to voids or delamination.

 

Why HV OEMs Choose This Material

Leading manufacturers of pulse power systems and HV generators specify TIA208R for the following reasons:

• Superior Dielectric Isolation: High dielectric strength and volume resistivity ensure reliable performance in high-stress electrical environments, preventing arcing and breakdown.

• Reduced Partial Discharge Risk: Excellent flowability allows the material to penetrate complex transformer windings and HV geometries, displacing air voids that lead to partial discharge.

• Simplified Manufacturing: The primerless adhesion to metals and plastics removes a manual process step, improving production throughput and reducing the risk of human error.

• Thermal & Mechanical Stability: Unlike rigid epoxies, this silicone gel absorbs thermal shock and vibration without cracking, maintaining insulation integrity over a wide operating temperature range (-40°C to +150°C+).

Key Technical Properties for HV Applications

• High Dielectric Strength: Essential for insulating HV components in compact footprints.

• Primerless Adhesion: Bonds securely to Aluminum, Copper, PBT, PPS, and Polycarbonate without surface pretreatment.

• Thermal Conductivity (0.7 W/m∙K): Effectively dissipates heat generated by HV transformers and power electronics.

• UL Rated & Flame Retardant: UL94V-0 certified with a UL RTI of 150°C for safety-critical applications.

• Reworkable: The semi-rigid nature allows for easier removal compared to hard epoxies, facilitating repair or component analysis during prototyping.

Typical High-Voltage Applications

TIA208R is optimised for encapsulating components where electrical isolation is paramount:

• High-Voltage Power Supplies: Potting of flyback transformers, multipliers, and rectifiers.

• Medical X-ray Generators: Insulation of tube heads and HV connectors.

• Pulse Power Systems: Protection of capacitors and switching electronics.

• Automotive EV Systems: On-board chargers (OBC) and DC/DC converters requiring HV isolation.

• LED Ballasts & Micro-Inverters: Protecting drive electronics from environmental and electrical stress.

Potting in LED Light Bulbs 2 identical E26 lightbulbs with thermocouple attached to capacitor. One potted with TIA208R the other Unpotted Turn the bulbs on and measured operating temperature with ambient temperature 24.5°C

TIA208R resulted in a 16 % reduction in operating temperature

Reduced Operating Temperatures

In comparative testing, LED components potted with TIA208R showed a 16% reduction in operating temperature compared to unpotted units. For HV electronics, cooler operation directly translates to longer dielectric life and reduced thermal aging of insulation materials.

Curing & Process

• • Room Temperature or Heat Cure: Cures quickly with heat for fast production lines or at room temperature to protect sensitive components.

  • Adhesion Build: Adhesion strength continues to build over time, ensuring a durable, void-free interface that resists moisture ingress and corona discharge.

Temperature and Viscosity Relationship

The formulation is designed to maintain a stable viscosity during dispensing, ensuring consistent flow into high-density HV windings before curing.

Stable properties under harsh operating conditions

Related Technical Resources

• Compare with other Potting Silicones

• Learn more about Momentive SilCool™ Thermal Management