Ceramic substrate

aluminum oxide

Product description
Zirconia-toughened alumina (ZTA) substrates combine the mechanical strength of zirconia with the stability of alumina to deliver dense, white substrates with excellent surface finish, high reflectance and superior thermal shock resistance. Designed for reliable performance in medium-power electronic and optical assemblies, these substrates are suited to power modules, LED systems and precision instrumentation where machining accuracy and thermal reliability are required.

Key features

• High flexural strength (≥550 MPa)
• High reflectance (≥95%)
• Excellent thermal shock resistance (≥10 at 800°C)
• Good machinability and polishing capability

Typical applications

• Medium-power power supply modules
• Medium-power LED lighting modules
• Measuring and precision instruments

Material properties
Project: ZTA
Material system: Al2O3 / ZrO2
Appearance: dense white
Surface roughness (Ra): 0.2–0.5 μm
Density: ≥3.85 g/cm3
Flexural strength (3-point): ≥550 MPa
Vickers hardness (4.9 N): ≥14 GPa
Water absorption: 0%
Thermal conductivity (25°C): ≥23 W/(m·K)
Coefficient of thermal expansion (25–500°C): 6.6–7.5 ×10^-6 /°C
Thermal shock resistance (800°C, specified time): ≥10
Specific heat: 720 J/(kg·K)
Permittivity (1 MHz/25°C): 10–11
Dielectric loss (1 MHz/25°C): ≤3×10^-4
Volume resistivity (25°C): >10^14 Ω·cm
Dielectric strength: >15 kV/mm
Reflectance: ≥95%

Specifications & dimensions
Material (ZTA): Available effective sizes (A, B): 50.8–190 mm
Thickness (T): 0.25–1.5 mm
Thickness tolerance: ±5% (min ±0.03 mm)
Warp (C): ≤0.3%
Surface finish: Ra 0.2–0.5 μm
Sizes, thickness and surface finish can be customized on request

Processing

• Laser cutting
• Grinding and polishing

Tolerances & surface roughness (excerpt)
Inner dimension tolerance: standard ±0.05 mm (premium ±0.03 mm)
Outer dimension tolerance: standard ±0.15 mm (premium ±0.1 mm)
Hole tolerance (φ0.07–0.15 mm): standard ±0.05 mm (premium ±0.03 mm)
Hole tolerance (φ > 0.15 mm): standard ±0.1 mm (premium ±0.02 mm)
Ground surface roughness: standard 0.3–0.6 μm (premium 0.3–0.5 μm)
Micro-ground surface roughness: standard 0.1–0.4 μm (premium 0.1–0.3 μm)
Polished surface roughness: standard ≤0.1 μm (premium ≤0.05 μm)

Notes
Specifications vary by material (Al2O3, ZTA, AlN, Si3N4, etc.). Sizes, thicknesses and surface roughness are customizable to meet project requirements.