Aluminum oxide substrate

ceramicaluminum nitride

Product overview
Our silicon nitride (Si₃N₄) substrates (SN-90) combine high thermal conductivity, elevated mechanical strength and excellent fracture toughness to provide stable performance for high-power electronics and thermal management applications. Their coefficient of thermal expansion is close to silicon, and they offer strong thermal shock resistance. Precision-machined surfaces and customizable specifications make these substrates suitable for IGBT power modules, high-power heat sinks and advanced wireless modules.

Features

• High thermal conductivity (≥85 W/(m·K) at 25℃)
• Thermal expansion coefficient close to silicon wafer (2–4 ×10⁻⁶ mm/℃, 25–500℃)
• High bending strength (≥750 MPa) and Vickers hardness (≥14 GPa)

Application

• High-power IGBT power modules
• High-power heat sinks and thermal spreaders
• Advanced wireless modules and RF components

Material Properties Table
Project | Test conditions | Unit | Si₃N₄ (SN-90)
Material | - | - | Si₃N₄
Appearance | - | - | grey
Surface roughness | Ra | μm | 0.2–0.75
Density | - | g/cm3 | ≥3.2
Physical properties - Bending strength | 3-point bending resistance | MPa | ≥750
Vickers hardness | Load 4.9 | GPa | ≥14
Water absorption | - | % | 0
Thermal performance - Thermal conductivity | 25℃ | W/(m·K) | ≥85
Linear thermal expansion coefficient | 25–500℃ | ×10^-6 mm/℃ | 2–4
Thermal shock resistance | 800℃ | Time | ≥10
Specific heat | - | J/(kg·K) | 680
Electrical properties - Dielectric constant | 1MHz/25℃ | - | 7–8
Dielectric loss | 1MHz/25℃ | ×10^-4 | ≤4
Volume resistivity | 25℃ | Ω·cm | > 10^14
Breakdown voltage | - | kV/mm | > 15

Specifications and Dimensions
Material | Unit | Al₂O₃ | ZTA | AlN | Si₃N₄
Effective dimensions (A, B) | mm | 50.8–190 | 50.8–190 | 50.8–190 | 138 × 190
Thickness (T) | mm | 0.25–1.5 | 0.25–1.5 | 0.25–1.0 | 0.25, 0.32
Thickness tolerance | mm | ±5% (Min ±0.03mm) | ±5% (Min ±0.03mm) | ±5% (Min ±0.03mm) | ±5% (Min ±0.03mm)
Warpage (C) | mm | ≤0.3% | ≤0.3% | ≤0.3% | ≤0.3%
Surface roughness | μm | 0.2–0.6 | 0.2–0.5 | 0.2–0.75 | 0.2–0.75
Note: Size, thickness and surface roughness can be customized

Processing

• Laser cutting and drilling
• Grinding and polishing (sheet roughness control)

Processing tolerances and surface finish
Internal dimension tolerance (Qualified) | ±0.05mm | (Special Grade) ±0.03mm
External dimension tolerance (Qualified) | ±0.15mm | (Special Grade) ±0.1mm
Hole tolerance (φ0.07–0.15mm) (Qualified) | ±0.05mm | (Special Grade) ±0.02mm
Hole tolerance (φ > 0.15mm) (Qualified) | ±0.1mm | (Special Grade) ±0.02mm
Surface roughness (Qualified) - Grinding: 0.3–0.6 μm; Fine grinding: 0.1–0.4 μm; Polishing: ≤0.1 μm
Surface roughness (Special Grade) - Grinding: 0.3–0.5 μm; Fine grinding: 0.1–0.3 μm; Polishing: ≤0.05 μm

Technical specifications

• Commercial name: Silicon Nitride (Si₃N₄) Substrates
• Material: Si₃N₄ (SN-90)
• Appearance: grey
• Surface roughness: Ra 0.2–0.75 μm (depending on process)
• Density: ≥3.2 g/cm³
• Bending strength (3-point): ≥750 MPa
• Vickers hardness (load 4.9): ≥14 GPa
• Water absorption: 0%
• Thermal conductivity (25℃): ≥85 W/(m·K)
• Linear thermal expansion (25–500℃): 2–4 ×10^-6 mm/℃
• Thermal shock resistance (800℃): ≥10
• Specific heat: 680 J/(kg·K)
• Dielectric constant (1MHz/25℃): 7–8
• Dielectric loss (1MHz/25℃): ≤4 ×10^-4
• Volume resistivity (25℃): >10^14 Ω·cm
• Breakdown voltage: >15 kV/mm
• Typical available size for Si₃N₄: 138 × 190 mm; typical thicknesses: 0.25 mm, 0.32 mm (other sizes and thicknesses customizable)
• Thickness tolerance: ±5% (Min ±0.03 mm)
• Warpage: ≤0.3%
• Processing: laser cutting, grinding and polishing; tolerances for internal/external dimensions and holes available