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DOWSIL™ TC-5533 Gap Filler
- Designed specifically for EV battery module
- Controlled siloxane volatility
- Vertical Stability
Product Description
DOWSIL™ TC-5533 Thermally Conductive Gap Filler is a two-part, room-temperature-curing silicone thermal interface material specifically engineered for electric vehicle (EV) battery thermal management applications. Featuring 3.0 W/m·K thermal conductivity, controlled siloxane volatility, and a soft, compliant cured elastomer, TC-5533 efficiently transfers heat from battery modules and electronic components to cooling plates, cold plates, or thermal management units while minimizing assembly stress. Designed for automated dispensing and high-volume manufacturing, the material remains stable on vertical surfaces, exhibits low abrasion to dispensing equipment, and delivers long-term reliability under temperature and humidity cycling conditions. Its combination of thermal performance, dielectric insulation, flame resistance, and processability makes TC-5533 an excellent solution for EV battery packs, energy storage systems, power electronics, and automotive control modules.
Key Features
3.0 W/m·K thermal conductivity for efficient heat dissipation.
Designed specifically for EV battery module thermal management.
Controlled siloxane volatility for improved long-term reliability.
Soft, compliant cured elastomer for vibration damping and stress relief.
Low assembly force requirements to protect sensitive battery cells and electronics.
Excellent stability during temperature and humidity cycling.
Vertical stability in both uncured and cured conditions.
Two-part 1:1 mix ratio by weight or volume.
Automated dispensing compatible with low-abrasion filler technology.
UL 94 V-0 flame classification for enhanced safety compliance.
Dielectric strength of 11 kV/mm for electrical insulation.
Operating temperature range of -45°C to 125°C, with short-term exposure up to 200°C.
Suitable for EV battery modules, battery cooling plates, energy storage systems, power electronics, onboard chargers, DC-DC converters, and automotive electronic control units.
Technical Specifications
| General Properties | |||||
| Color Color The color | Part A: White | Part B: Blue | ||||
| Component System Component System Describes the number of components that must be supplied, mixed, or activated before application or cure. | Two Part | ||||
| Density Density Volumetric mass per unit | 2.6 kg/m3 | ||||
| Mix Ratio Mix Ratio The amount of a constituent divided by the total amount of all other constituents in a mixture | 1:1 | ||||
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| Physical Properties | |||||
| Thixotropic index Thixotropic index Thixotropic Index is a ratio of a material s viscosity at two different speeds in Ambient temperature, generally different by a factor of ten. A thixotropic material s viscosity will decrease as agitation or pressure is increased. It indicates the capability of a material to hold its shape. Mayonnaise is a great example of this. It holds its shape very well, but when a shear stress is applied, the material easily spreads. It helps in choosing a material in accordance to the application, dispense method and viscosity of a material. | 5-6 | ||||
| Viscosity (Part A) | @10/s 50000 mPa.s | ||||
| Viscosity (Part B) | @10/s 50000 mPa.s | ||||
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| Curing Conditions | |||||
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| Mechanical Properties | |||||
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| Thermal Properties | |||||
| Thermal Conductivity Thermal Conductivity Thermal conductivity describes the ability of a material to conduct heat. It is required by power packages in order to dissipate heat and maintain stable electrical performance. Thermal conductivity units are [W/(m K)] in the SI system and [Btu/(hr ft °F)] in the Imperial system. | 3.0 W/m.K | ||||
| UL 94 Rating UL 94 Rating Flammability rating classification. It determines how fast a material burns or extinguishes once it is ignited. HB: slow burning on a horizontal specimen; burning rate less than 76 mm/min for thickness less than 3 mm or burning stops before 100 mm V-2: burning stops within 30 seconds on a vertical specimen; drips of flaming particles are allowed. V-1: burning stops within 30 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed. V-0: burning stops within 10 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed. 5VB: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may develop a hole. 5VA: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may not develop a hole | V0 | ||||
| Electrical Properties | |||||
| Dielectric Strength Dielectric Strength Dielectric strength is measured in kV per mm and is calculated by the Breakdown voltage divided by the thickness of the tested material. Those two properties go hand in hand and while Breakdown voltage is always thickness dependent, dielectric strength is a general material property. As an example, the dielectric strength of Polyimide is 236 kV/mm. If we place 1mm of Polyimide between two electrodes, it will act as an insulator until the voltage between the electrodes reaches 236 kV. At this point it will start acting as a good conductor, causing sparks, potential punctures and current flow. | 11 kV/mm | ||||
Additional Information
DOWSIL™ TC-5533: Thermally Conductive Gap Filler for EV Battery Modules
DOWSIL™ TC-5533 Thermally Conductive Gap Filler is a two-part, room-temperature-curing silicone gap filler designed for effective thermal management of EV battery modules and other heat-generating electronic assemblies. With 3.0 W/m·K thermal conductivity, controlled siloxane volatility, low assembly forces, and long-term stability during temperature and humidity cycling, TC-5533 helps transfer heat from battery modules to cooling units while providing a soft, compliant thermal interface.
EV battery thermal gap filling with controlled volatility — TC-5533 combines 3.0 W/m·K thermal conductivity, low assembly force, vertical stability, and dispensing-friendly processing for battery module cooling.
Once cured, the silicone gap filler forms a soft elastomer that supports dielectric insulation, environmental protection, and stress relief against vibration, shock, and thermal expansion mismatch in EV battery systems.
Designed for EV battery cooling units — suitable for transferring heat from battery modules or other heat-generating components to cooling plates, housings, or thermal management units.
TC-5533 stays in place after dispensing, supports low assembly force, and is designed for automated dispensing with low abrasion and a wide application process range.
3.0 W/m·K Thermal Conductivity • EV Battery Modules • Controlled Volatility • UL 94 V-0
Features & Benefits
- 3.0 W/m·K thermal conductivity — supports efficient battery module heat transfer.
- Room-temperature cure — cures at 25 °C with optional heat acceleration.
- Controlled siloxane volatility — supports long-term electronic reliability.
- Low assembly forces — helps protect sensitive battery and electronic components.
- Stays in place — holds vertical position in cured and uncured states.
- Temperature and humidity cycling stability — designed for EV battery environments.
- Dispensing equipment friendly — low abrasion and wide application process range.
- UL 94 V-0 flame classification — suitable for flame-rated battery and electronics assemblies.
Typical Applications
- EV battery module thermal management.
- Battery module-to-cooling unit interfaces.
- Battery cooling plates and trays.
- Energy storage modules.
- Power electronics thermal gap filling.
- Automotive electronics and control modules.
- Automated dispensing applications.
Thermal Challenges in EV Battery Modules
EV battery systems require thermal materials that can efficiently dissipate heat while accommodating module tolerances, assembly pressure limits, vibration, and long-term environmental exposure. DOWSIL™ TC-5533 helps address these challenges with a soft, compliant silicone gap filler that transfers heat from battery modules to cooling units while maintaining reliable performance during temperature and humidity cycling.
Engineering Data for DOWSIL™ TC-5533
| Property | DOWSIL™ TC-5533 | Condition / Note |
|---|---|---|
| Type | Two-part silicone gap filler | Room-temperature curing |
| Mix Ratio | 1:1 | By weight or volume |
| Color | Part A: White Part B: Blue | Typical appearance |
| Mixed Viscosity | 50 Pa·s | At 10 s-1 |
| Thixotropic Index | 5–6 | 1 s-1 / 10 s-1 |
| Working Time | 60 minutes | At 25 °C |
| Density, Cured | 2.6 | At 25 °C |
| Thermal Conductivity | 3.0 W/m·K | ASTM D5470 |
| Cure Time at 25 °C | 24 hours | Vertical stability for thin bondlines; full cure may take up to 7 days |
| Hardness | Shore 00 65 | Soft compliant material |
| Dielectric Strength | 11 kV/mm | Cured material |
| UL Flame Classification | UL 94 V-0 | Flame classification |
| Operating Temperature | -45 °C to 125 °C | After cure completion |
| Short-Term High Temperature Exposure | Up to 200 °C | Short periods only |
| Shelf Life | 6 months | At 25 °C |
*Typical properties are not intended for specification writing. Verify performance under actual application, substrate, assembly, compression, cure, and reliability conditions.
Where DOWSIL™ TC-5533 Fits
- Battery modules
- Cooling plates
- Battery trays
- ESS modules
- Battery packs
- Thermal management units
- Meter-mix dispensing
- Vertical placement
- Wide process window
Mixing, Dispensing & Cure
Mixing
Mix Part A and Part B at a 1:1 ratio by weight or volume. Static mixing is recommended for manual and automated mixing.
Dispensing
Automated airless dispense equipment can reduce voids and avoid de-airing. Purge trapped air or clear fluid during material change-over.
Curing
Cures at room temperature or with heat acceleration. Thin bondlines can achieve vertical stability in 24 hours at 25 °C; full cure may take up to 7 days.
How TC-5533 Supports EV Battery Module Design
| Design Challenge | DOWSIL™ TC-5533 Benefit |
|---|---|
| EV battery modules require efficient heat removal. | 3.0 W/m·K thermal conductivity supports heat transfer to cooling units. |
| Battery cells and electronics can be sensitive to high assembly pressure. | Low assembly forces help protect sensitive components. |
| Dispensed material must stay in place during pack assembly. | Thixotropic behavior supports vertical stability in cured and uncured states. |
| High-volume production requires equipment-friendly material flow. | Low-abrasion ceramic fillers support dispensing equipment life and process flexibility. |
Ready to Evaluate DOWSIL™ TC-5533?
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