LED Thermal Bonding Silicone Adhesive 1.5 W/mK

LED Thermal Bonding Silicone Adhesive — 1.5 W/mK

A one-part RTV silicone adhesive formulated specifically for LED thermal bonding applications where heat dissipation and structural adhesion must happen in a single step. Bonds LED packages to aluminum substrates, MCPCB heat spreaders, and metal-core boards while providing 1.5 W/mK thermal conductivity and electrical insulation. Cures at room temperature to a permanently flexible elastomer rated for −50 °C to +200 °C — absorbing the coefficient of thermal expansion (CTE) mismatch between silicon LED dies, metal heat sinks, and ceramic packages without stress cracking.

At a Glance

Why LED Assemblies Need a Dedicated Thermal Bonding Adhesive

High-brightness LEDs convert a significant portion of electrical input into heat rather than light. If that heat is not efficiently transferred away from the junction, the LED experiences elevated junction temperatures — accelerating lumen depreciation, shifting color temperature, and shortening operational life. The thermal interface between the LED package and its substrate or heat sink is therefore a critical reliability factor, not an afterthought.

Traditional approaches — thermal grease plus mechanical clips, or double-sided thermal tapes — each carry trade-offs that become problematic in LED manufacturing:

This RTV silicone adhesive addresses all four problems: it cures to a permanent elastomer that stays in place, eliminates mechanical fasteners, fills irregular gaps as it cures, and maintains flexibility across the full operating temperature range.

How These Specifications Translate to LED Assembly Decisions

Thermal Conductivity: 1.5 W/mK

1.5 W/mK provides meaningful thermal transfer for medium-power LED packages — including COB (chip-on-board) modules, mid-power SMD LEDs, and LED strips mounted on aluminum substrates. For each watt of LED power, the adhesive conducts heat from the package base through the bond line to the heat sink or MCPCB, reducing the thermal resistance that would otherwise trap heat at the junction. For high-power LED arrays pushing beyond 50 W or dense COB designs with heat flux above 10 W/cm², consider evaluating the 3 W/mK grade in our silicone adhesive line for enhanced thermal transfer.

One-Part RTV Cure: No Mixing, No Oven

The adhesive dispenses directly from standard cartridges and cures by reacting with atmospheric moisture at room temperature. No two-part metering, no mixing equipment, no oven cure — simplifying LED assembly lines and reducing capital equipment needs. Skin-over occurs in 15–30 minutes at 23 °C and 50% relative humidity; cure progresses at approximately 2–3 mm per 24 hours. For high-volume LED production requiring faster throughput, heat-assisted cure can accelerate the process — discuss your target cycle time with our technical team.

Operating Temperature: −50 °C to +200 °C

LED applications span cold-start outdoor lighting in winter conditions to sustained high-temperature operation in enclosed fixtures. This adhesive maintains flexibility and dielectric properties across the full range. The cured silicone elastomer absorbs CTE mismatch between the LED package (silicon, ceramic), the substrate (aluminum, copper, FR-4), and the heat sink — preventing the delamination and bond failure that rigid adhesives experience under thermal cycling.

Dielectric Strength: ≥15 kV/mm

The cured adhesive is electrically insulating. This prevents current leakage between the LED package and the heat sink — important when the heat sink is at a different electrical potential than the LED circuit. In LED drivers and power supply assemblies where high-voltage isolation is a safety requirement, verify your creepage and clearance distances against the actual bond line thickness in your design.

Non-Sag Paste for Vertical and Overhead Bonding

The paste viscosity keeps the adhesive where dispensed — on vertical LED board edges, overhead downlight housings, and curved heat sink surfaces — without slumping or flowing during cure. This eliminates the need for fixturing in most LED assembly configurations and reduces material waste from overflow.

LED Thermal Bonding Application Areas

• COB LED module bonding — attach chip-on-board LED arrays directly to aluminum or copper heat spreaders

• SMD LED reflow replacement — bond surface-mount LEDs to MCPCB substrates where solder reflow is impractical

• LED street light and high-bay fixtures — secure LED packages to finned aluminum heat sinks in outdoor and industrial lighting

• LED downlight and spotlight assemblies — bond LED engines to metallic housings in directional lighting with tight thermal budgets

• LED strip and module thermal coupling — improve heat transfer from flexible LED strips to rigid aluminum channels

• LED driver and power supply thermal management — bond heat-generating driver components to enclosures for conduction cooling

For applications outside this list, describe your LED package type, substrate material, and target thermal performance in your inquiry — we will confirm suitability and recommend the appropriate grade.

Substrate Compatibility

The adhesive bonds without primer to:

• Aluminum (anodized and bare) — the most common LED heat sink and MCPCB substrate

• Copper — used in high-performance thermal spreaders

• Ceramics (alumina, aluminum nitride) — used in COB LED submounts

• Glass-filled epoxy laminates (FR-4) — standard PCB material

• Plated surfaces (nickel, silver) — common on LED component terminals

For low-surface-energy plastics, coated metals, or specialty substrates, request adhesion testing data or provide samples for evaluation before specifying.

Buyer FAQ

Company Credentials

Manufactured by TIANJIN SHENGWANG ELECTRONIC CHEMICAL PLANT (SW ADHESIVE), a specialist producer of industrial adhesives, sealants, and electronic chemical products based in Tianjin, China, operating since 1993. The company holds ISO 9001:2015 certification for quality management and maintains in-house testing capabilities including viscosity meters, tensile strength testers, and environmental chambers for performance validation. Products are formulated to meet RoHS and REACH compliance for global B2B electronics manufacturing.