Thermal Conductive Material

Thermal Interface Materials for Electronics Cooling from Eata Electronic

Figure 1: Thermal conductive silicone pad installed between a processor chip and aluminum heatsink

The relentless drive toward higher power density in modern electronics has made thermal management one of the most critical engineering disciplines across virtually every industry segment. From the latest GPU architectures pushing hundreds of watts through ever-smaller die areas, to GaN power amplifiers in 5G base stations operating at elevated junction temperatures, to compact medical imaging equipment where reliability failures are not an option, the ability to efficiently transfer heat from source to sink determines whether a design succeeds or fails. At the heart of every thermal solution lies the thermal interface material, a deceptively simple substance that fills microscopic air gaps between mating surfaces, creating a continuous low-resistance pathway for heat conduction. Without this critical layer, even the most sophisticated liquid cooling system or vapor chamber cannot perform to specification, because trapped air pockets act as thermal insulators that choke heat flow precisely where it matters most.

Eata Electronic offers an extensive range of thermally conductive materials engineered to address every thermal interface challenge encountered in research and industrial electronics. Our catalog spans thermal greases and pastes, silicone-based thermal pads and gap fillers, phase change materials, thermal gels, thermally conductive adhesives, and ceramic filler powders for in-house formulation work. Each product line includes multiple grades with varying thermal conductivity values, hardness levels, electrical isolation properties, and temperature ratings, enabling our customers to identify the precise material that matches their heat dissipation requirements, assembly process constraints, and long-term reliability targets.

Figure 2: Thermal conductive grease being dispensed from a syringe onto a CPU heat spreader surface

Thermal Grease and Thermal Paste

Thermal grease, also known as thermal paste or thermal compound, remains the most widely used thermal interface material in electronics assembly. It consists of a silicone oil or synthetic hydrocarbon base loaded with thermally conductive ceramic fillers such as aluminum oxide (alumina), zinc oxide, boron nitride, or aluminum nitride. The paste consistency allows the material to flow and conform to microscopic surface irregularities, displacing air and establishing intimate thermal contact between component and heatsink.

Our thermal grease products span thermal conductivity values from 1.5 W per meter-Kelvin for cost-effective general-purpose formulations up to 6 W per meter-Kelvin for high-performance applications involving power semiconductors, high-brightness LEDs, and overclocked processors. Key specifications include low thermal resistance below 0.01 degrees Celsius per square centimeter per watt at 50 psi, excellent surface wetting characteristics, minimal oil separation and evaporation over the rated service life, and wide operating temperature range from minus 50 to plus 200 or even 230 degrees Celsius depending on grade. Standard packaging includes syringes for manual application, tubes for automated dispensing systems, and bulk containers for high-volume production lines.

Application Considerations

Successful implementation of thermal grease requires attention to application method, quantity control, and surface preparation. For research and small-batch environments, a manual dot or line pattern followed by heatsink pressure spreading provides acceptable results. High-volume manufacturing benefits from screen printing, stencil printing, or precision pneumatic dispensing systems that ensure consistent deposit weight and coverage area across thousands of assemblies. The surfaces to be joined should be cleaned with isopropyl alcohol to remove oils, dust, and oxidation residues before grease application.

Thermal Conductive Silicone Pads and Gap Fillers

Thermal conductive pads, alternatively called thermal gap pads or thermal interface pads, are pre-cured sheets of silicone elastomer loaded with thermally conductive ceramic fillers. These solid-state materials offer significant practical advantages over grease in manufacturing environments where cleanliness, consistency, and ease of handling are priorities. Because each pad is die-cut to precise dimensions, every assembly receives exactly the same material quantity and coverage area, eliminating the variability inherent in manual grease application.

Our silicone pad portfolio encompasses thermal conductivity grades from 1 to 12 W per meter-Kelvin, with hardness values ranging from Shore OO 20 for ultra-soft conformable formulations to Shore OO 80 for firmer pads that resist compression set in stacked assemblies. Thickness options from 0.25 to 10 millimeters accommodate gap-filling requirements from tight processor-to-heatsink interfaces to larger tolerance stack-ups in power module assemblies. Available configurations include plain pads, fiberglass-reinforced pads for enhanced dielectric strength and cut-through resistance, pads with single-sided or double-sided pressure-sensitive adhesive for mechanical attachment, and thermally conductive insulating pads engineered for high-voltage isolation between 4 and 20 kV per millimeter.

Figure 3: Stack of thermal conductive silicone gap pads in blue and grey color variations and multiple thicknesses

Silicone-Free Thermal Pads

Certain applications, particularly in aerospace, optical, and high-vacuum environments, cannot tolerate silicone due to outgassing concerns. Our silicone-free thermal pads utilize acrylic, urethane, or olefin-based polymer matrices loaded with the same high-performance ceramic fillers, delivering comparable thermal conductivity without the volatile siloxane compounds that can contaminate optical surfaces or condense on cold regions in vacuum chambers. These non-silicone pads meet NASA outgassing requirements per ASTM E595 and are qualified for satellite electronics, telescope instrumentation, and cleanroom manufacturing equipment.

Phase Change Materials (PCM)

Phase change materials represent an innovative thermal interface solution that bridges the gap between the ease of handling offered by solid pads and the ultimate thermal performance achieved by grease. At room temperature, PCMs behave as dry, non-tacky films that are simple to handle, position, and ship. When the device reaches its operating temperature, typically between 45 and 60 degrees Celsius, the material softens and flows to wet the mating surfaces, establishing a bond line thickness as thin as 0.05 millimeters with correspondingly low thermal resistance. Upon cooling, the material returns to its solid state without migrating or pumping out, maintaining consistent performance across countless thermal cycles.

Eata Electronic supplies phase change materials in several formats: freestanding films in thicknesses from 0.125 to 0.5 millimeters, polyimide carrier-supported films that combine the dielectric strength of Kapton with the thermal performance of conductive wax, and aluminum foil-supported variants for applications requiring additional heat spreading. Thermal conductivity ranges from 1.6 to 8 W per meter-Kelvin. Phase change temperatures of 45, 51, 55, and 60 degrees Celsius are available to match specific device operating conditions.

How PCM Outperforms Traditional Pads

The key advantage of phase change materials lies in their ability to achieve thinner bond lines than pre-cured pads. A traditional silicone pad compressed to 0.5 millimeters may exhibit thermal resistance of 0.15 degrees Celsius per square centimeter per watt, while a PCM that flows to 0.1 millimeters can achieve resistance below 0.07 degrees Celsius square centimeter per watt, nearly halving the temperature drop across the interface. This performance improvement becomes critical in high-power density applications such as AI accelerator chips, electric vehicle inverters, and advanced RF power amplifiers where every degree of junction temperature reduction extends device life and improves reliability.

Figure 4: Phase change thermal interface material film with glossy wax-like surface partially peeled from protective liner

Thermal Conductive Gels

Thermal gels occupy the space between greases and cured pads, offering a lightly cross-linked paste-like material that combines the conformability and low thermal resistance of grease with significantly reduced pump-out and dry-out tendencies. These single-part materials require no curing and can be dispensed through standard automated equipment. The partially cross-linked structure provides enough internal cohesion to resist migration under thermal cycling, while the soft modulus enables excellent surface wetting even at low assembly pressures. Thermal conductivity from 2 to 8 W per meter-Kelvin covers applications ranging from consumer electronics to industrial power modules.

Thermally Conductive Adhesives

When the thermal interface material must also serve a structural function, thermally conductive adhesives provide both heat transfer and mechanical bonding in a single material. One-part and two-part epoxy, silicone, and acrylic formulations are available, with ceramic filler loadings producing thermal conductivity from 0.8 to 6 W per meter-Kelvin while maintaining lap shear strengths from 5 to 25 MPa depending on chemistry. These adhesives eliminate the need for mechanical clamps, screws, or spring clips, reducing assembly complexity and enabling designs where fasteners cannot be accommodated. Applications include bonding heat sinks to ceramic substrates, attaching thermal management hardware to plastic enclosures, and potting power modules where both thermal conduction and vibration resistance are required.

Thermal Conductive Ceramic Filler Powders

For research institutions and advanced materials development programs that formulate their own thermal interface compounds, Eata Electronic supplies high-purity ceramic filler powders with precisely controlled particle size distributions and surface treatments. These powders can be dispersed into silicone fluids, epoxy resins, or other carrier matrices to create custom thermal materials with properties tailored to specific application requirements.

• Spherical aluminum oxide (Al2O3) — Electrical insulator with thermal conductivity of 30 W/mK in bulk form, excellent filler packing density, and cost-effectiveness for general-purpose TIM formulation
• Hexagonal boron nitride (h-BN) — Often called white graphite, h-BN provides high thermal conductivity of 400 W/mK in-plane, electrical insulation, and low dielectric constant for advanced TIM and dielectric coating applications
• Aluminum nitride (AlN) — Among the highest thermal conductivity ceramic fillers at 170-230 W/mK, ideal for premium TIM formulations targeting maximum heat transfer with electrical isolation
• Zinc oxide (ZnO) — Moderate thermal conductivity with excellent cost-performance balance, widely used in silicone thermal grease formulations
• Spherical fused silica — Low thermal expansion coefficient, chemical inertness, and cost-effective filler for applications where moderate thermal conductivity is acceptable

Figure 5: Spherical alumina ceramic filler powder spilled from a glass vial onto a dark surface

Thermal Interface Material Selection Guide

Application Areas

The thermal conductive materials from Eata Electronic serve an extraordinarily broad spectrum of research and industrial thermal management challenges. In semiconductor packaging, our high-conductivity greases and phase change materials enable effective heat removal from flip-chip BGAs, IGBT modules, and SiC MOSFET power devices. In LED lighting and display manufacturing, silicone thermal pads provide both electrical isolation and reliable heat conduction from COB arrays to heat sinks. In telecommunications infrastructure, thermally conductive gap fillers accommodate the large tolerance variations between 5G base station power amplifiers and their chassis-mounted cooling systems. In electric vehicle power electronics, phase change materials and thermal gels maintain low junction temperatures in traction inverters and onboard chargers where thermal cycling durability is paramount. In medical equipment, silicone-free pads meet the stringent outgassing and reliability requirements of MRI systems, CT scanners, and diagnostic instrumentation. In aerospace and defense, our materials support radar systems, electronic warfare platforms, and satellite payloads where failure is not an option.

Custom Formulation and Application Support

While our standard catalog addresses the majority of thermal interface requirements, certain research programs and production applications demand materials with properties that fall outside conventional specifications. Eata Electronic welcomes inquiries for custom thermal material development, offering formulation engineering, small-batch prototyping, and scale-up production services.

Our development team can adjust filler loading, particle size distribution, polymer matrix chemistry, crosslink density, and additive packages to achieve specific thermal conductivity targets, hardness values, adhesion properties, or temperature ratings. We support die-cutting, waterjet machining, kiss-cut roll formats, and precision slitting to deliver finished thermal pads in exact customer-specified dimensions. For projects involving novel thermal management approaches, our application engineers provide joint development support including material selection guidance, assembly process recommendations, and thermal performance modeling.

For Research or Industrial Raw Materials, Not For Personal Medical Use!