Thermal interface materials (TIMs) are critical enablers of heat dissipation in power electronics, LED lighting, IGBT modules, and semiconductor devices. Among various TIM formats, thermal grease (also called thermal paste or TIM grease) remains the highest-volume thermal interface solution globally, driven by its low thermal resistance, ease of application, and broad compatibility across device architectures. This procurement guide covers the key specifications, selection logic, and supplier evaluation framework for thermal grease TIM in 2026.
1. Why Thermal Grease Still Dominates TIM Procurement
Despite the emergence of phase-change materials, thermal pads, and graphene-based solutions, thermal grease retains its market dominance due to:
- Lowest thermal resistance among non-liquid TIMs (R_contact as low as 0.01°C·cm²/W with proper surface preparation)
- Highly adjustable viscosity and filler composition for diverse application scenarios
- Mature supply chain with globally diversified manufacturers
- Cost-effectiveness for high-volume consumer electronics and automotive applications
- Applicability across a wide bond line thickness (BLT) range (20–200μm)
2. Key Procurement Specifications for TIM Grease
2.1 Thermal Conductivity
Thermal conductivity (k, W/m·K) is the primary selection criterion. Current market offerings span a wide range:
- Standard greases: 0.5–2.5 W/m·K — consumer electronics, CPU/GPU cooling
- Mid-range greases: 3–6 W/m·K — LED modules, telecom base stations
- High-performance greases: 6–10 W/m·K — IGBT modules, EV power electronics, RF amplifiers
- Ultra-high thermal greases: >10 W/m·K — SiC/GaN power devices, AI accelerator modules
Note: Thermal conductivity is typically measured via ASTM D5470 (steady-state method). Buyers should request k-values measured at standardized conditions (35°C, 100 PSI contact pressure) for fair comparison.
2.2 Viscosity and Workability
Viscosity determines pumpability, dispensability, and coverage uniformity:
- Thixotropic index: Greases with high thixotropy resist pump-out in vibration environments (automotive, industrial)
- Application temperature range: Typical working range: -40°C to +180°C; high-Tg formulations extend to 200–250°C
- Oil bleeding rate: Lower bleeding (<0.5% at 80°C/96h) is critical for electronics to avoid contamination of connectors and PCB traces
- Shelf life: Typically 12–24 months sealed; assess for long supply chains
2.3 Thermal Resistance (R_th) and Contact Pressure
Pure thermal conductivity does not reflect real-world performance. Thermal resistance depends on:
- Bond line thickness (BLT): thinner BLT → lower R_th
- Surface roughness: rougher surfaces require higher fillermaterial to compensate air voids
- Contact pressure: most greases show R_th decreasing with increasing pressure up to ~100 PSI
Procurement tip: Request R_th vs. BLT curves from the supplier (typically per ASTM D5470) rather than accepting k-value alone.
2.4 Filler Type and Compositional Considerations
| Filler Type | Thermal Conductivity | Electrical Insulation | Typical Use |
|---|---|---|---|
| ZnO (zinc oxide) | ~25 W/m·K | Yes | Standard electronics, good cost balance |
| AlN (aluminum nitride) | ~140 W/m·K | Yes | High-power IGBT, SiC modules |
| Al₂O₃ (alumina) | ~30 W/m·K | Yes | Cost-sensitive, high-volume applications |
| BN (boron nitride) | ~300 W/m·K | Yes | High-frequency electronics (low dielectric loss) |
| Ag (silver) | ~429 W/m·K | No (electrically conductive) | Specialty applications, metal-base cooling |
| Carbon-based (graphite/CNT) | Variable | No (typically) | Non-electrical-insulating applications |
3. Application-Specific Selection Guide
3.1 IGBT and SiC/GaN Power Electronics
- Thermal conductivity: ≥5 W/m·K, prefer AlN or high-loading ZnO formulations
- Tg requirement: >130°C (ensure stability at high junction temperatures)
- Long-term thermal cycling resistance: validate under IEC 60068-2-14
- Automotive: AEC-Q200 compliance required
3.2 LED Lighting and Displays
- Thermal conductivity: 2–5 W/m·K depending on LED power density
- Low oil bleeding: critical to avoid optical surface contamination
- UV/photo-stability: for outdoor LED applications requiring extended service life
- Thermal resistance per LED chip manufacturer spec (typically R_th < 0.5°C·cm²/W)
3.3 Semiconductor Test and Burn-in Equipment
- High pump-out resistance (thixotropic formulations)
- Consistent reusability across thermal cycles
- Fast application and rework capability
4. Leading Global Suppliers (2026)
- First tier: Honeywell, Henkel (Bergquist), Shin-Etsu Chemical, Momentive (formerly GE Toshiba)
- Second tier: Wakefield-Vette, AOS Thermal Compounds, Laird Performance Materials, T-Global Technology
- Chinese domestic: KingBali (品固), Huayi Thermal (华亿热控), Shanghai Huayi, CoolTherm
- Specialty: 3M (Novec variants), Parker Chomerics (CHO-THERM)
Import substitution trend: Chinese domestic TIM grease manufacturers have gained significant share in mid-range applications (2–5 W/m·K) with 20–40% cost advantage. High-performance grades for SiC/GaN remain predominantly from Henkel, Momentive, and Shin-Etsu, though domestic players are rapidly closing the gap.
5. Supplier Evaluation Checklist
- □ Thermal conductivity certificate of analysis (CoA) per batch, referencing ASTM D5470
- □ Thermal resistance vs. BLT curve data package
- □ Reliability test report: thermal cycling (JEDEC JESD22-A104), HAST (JESD22-A110/A118)
- □ Oil bleeding rate test data (80°C/96h standard condition)
- □ RoHS, REACH, and halogen-free certification (IEC 61249-2-21 for halogen-free)
- □ Automotive qualification: AEC-Q200 test report (if automotive application)
- □ Shelf life and storage condition specification
- □ Technical support: FAE support for application process optimization
- □ Supply chain risk: production capacity, lead time, geographic footprint
- □ Customization capability: viscosity adjustment, filler loading, packaging options
6. Pricing Benchmarks (2026)
- Standard greases (1–3 W/m·K): USD 15–40/kg for bulk orders (>100kg)
- Mid-range greases (3–6 W/m·K): USD 40–120/kg
- High-performance greases (6–10 W/m·K): USD 120–350/kg
- SiC/GaN grade (>10 W/m·K, AlN filler): USD 300–600/kg
Procurement note: High filler loading (for thermal conductivity) directly impacts viscosity. Very high thermal conductivity greases may require high-pressure dispensing equipment. Total cost of ownership should include application equipment CAPEX when comparing formulations.
Conclusion
TIM grease procurement in 2026 demands a balance between thermal performance requirements, application process compatibility, and supply chain resilience. As power electronics push toward higher power densities with SiC and GaN devices, the thermal interface gap widens — making thermal grease selection and supplier qualification more critical than ever. Buyers should build multi-dimensional evaluation frameworks combining thermal performance data, reliability testing, and supply risk assessment rather than relying solely on published thermal conductivity values.
This article is for B2B industrial materials procurement reference only. Specification data sourced from publicly available industry resources and supplier datasheets. All procurement decisions should be verified against current datasheets and updated technical specifications.