High temperature use high grade 99% Alumina Ceramic Substrate

Material Composition
99% alumina ceramic substrates consist of ≥99% pure Al₂O₃ with minimal additives (e.g., rare-earth oxides like La₂O₃ or CeO₂ to optimize sintering and performance). The high purity reduces grain boundary impurities, enhancing thermal, mechanical, and electrical properties compared to lower-purity variants (e.g., 96% Al₂O₃).

Material 99% Al2O3
Color Ivory white
Density 3.85g/cm3
Max firing temperature 1650℃
Water absorbtion 0%
Vickers hardness 2300HV

Product Detail

Key Properties and Characteristics

Thermal Performance:
- Thermal Conductivity: 28–35 W/(m·K) — ~25% higher than 96% Al₂O₃ (24–28 W/(m·K)), enabling efficient heat dissipation in high-power devices.
- Thermal Expansion Coefficient: Low (7.2–8.2 ppm/K), closely matching silicon chips, reducing thermal stress.
Mechanical Strength:
- Flexural Strength: 380–450 MPa — >20% higher than 96% Al₂O₃ (300–350 MPa), ensuring structural stability under mechanical loads.
- Surface Smoothness: Ra < 0.1 μm, critical for precision circuit patterning and wire bonding.
Electrical Insulation:
- Dielectric Strength: 15–20 kV/mm, with low dielectric loss (tan δ < 0.0002 at 1 MHz), ideal for high-frequency circuits.
- Volume Resistivity: >10¹⁴ Ω·cm, preventing leakage currents.
Durability:
- Exceptional chemical resistance to acids/alkalis and high-temperature stability (operating limit: 1,600–1,700°C).

Applications

99% alumina substrates are essential in high-reliability and high-power electronic systems:

Power Electronics: Insulated metal substrates (IMS) for IGBTs, MOSFETs, and automotive control modules.
LED Packaging: High-power LED(heat sinks), leveraging superior thermal management to extend LED lifespan.
RF/Microwave Circuits: Substrates for antennas and filters in 5G/6G systems due to low signal loss.
Aerospace & Defense: Sensor housings and avionics requiring thermal shock resistance.

Parameter Table

Property	99% Al₂O₃	96% Al₂O₃
Alumina Purity	≥99%	96%
Density (g/cm³)	3.9–4.0	3.7–3.9
Thermal Conductivity (W/(m·K))	28–35	24–28
Flexural Strength (MPa)	380–450	300–350
Dielectric Constant (1 MHz)	9.8–10.2	9.1–9.5
CTE (ppm/K, 25–800°C)	7.2–8.2	7.6–8.2
Surface Roughness (Ra, μm)	<0.1	0.3–0.5
Cost	High	Moderate

Conclusion

99% alumina ceramic substrates deliver superior thermal management, mechanical robustness, and electrical insulation, making them indispensable in high-power electronics, RF systems, and LED packaging. While costlier and more challenging to manufacture than 96% Al₂O₃ (due to stringent sintering controls and rare-earth doping requirements)310, their performance justifies use in mission-critical applications. Ongoing research focuses on enhancing properties via nanoscale additives (e.g., graphene oxide composites) for next-gen devices.