Aluminum Nitride(AlN) Substrate
High-Performance Ceramic for Power Electronics, RF Devices, and Semiconductor Packaging
Aluminum Nitride (AlN) Substrates provide a reliable solution for thermal management in high-power applications. With a thermal conductivity up to 230 W/m·K and a CTE (Coefficient of Thermal Expansion) closely matched to SiC and GaN chips, our substrates offer a stable and durable foundation for your most demanding components. We offer standard, ultra-thin, and custom metallized solutions engineered to meet your specific design requirements.
- Superior Thermal Performance: A thermal conductivity of 230 W/m·K, over 10x better than alumina, ensures reliable high-power operation.
- Exceptional Thermal Matching: Its CTE is a perfect match for SiC and GaN chips, preventing thermal stress and improving long-term reliability.
- Safe and Non-Toxic Material: This high-performance ceramic is a non-toxic alternative to hazardous beryllium oxide.
- Highly Customizable: From ultra-thin substrates to complex metallization and custom shapes, we meet your specific design needs.
Table of Contents
Why Choose Aluminum Nitride (AlN) Substrates?
Aluminum Nitride (AlN) is a high-performance ceramic substrate combining ultra-high thermal conductivity (150–230 W/m·K), excellent electrical insulation, and a CTE (Coefficient of Thermal Expansion) closely matched to Si, SiC, and GaN chips. These properties make AlN indispensable for today’s power electronics, 5G RF modules, high-power LEDs, and semiconductor manufacturing equipment, where traditional alumina or even beryllium oxide cannot meet performance or safety requirements.
1. Exceptional Thermal Conductivity
Up to 9–10× higher than traditional Alumina (Al₂O₃) substrates, enabling rapid and efficient heat transfer from power semiconductor devices such as IGBTs, MOSFETs, and high-power LEDs. Lower junction temperatures mean longer device life and greater system reliability.
2. CTE Match with Silicon (4.6–5.7×10⁻⁶/K)
Close coefficient of thermal expansion to silicon (3.6–4.6×10⁻⁶/K) minimizes thermal stress, preventing cracks or delamination during temperature cycling.
3. Superior Electrical Insulation
Low, stable dielectric constant (8.5–9.0) and high resistivity maintained at elevated temperatures ensure effective circuit isolation for high-frequency and high-voltage designs.
4. Non-Toxic Alternative to BeO
Unlike Beryllium Oxide substrates, AlN is environmentally friendly and safe to handle, aligning with RoHS and REACH compliance.
We offer standard, ultra-thin, metallized, and custom-shaped AlN substrates with full traceability and certifications. Engineers and researchers can rely on our team for sample testing, thermal simulations, and design support—contact us today for a tailored solution.
Key Technical Specifications of AlN Substrates
| Property | Unit | Typical Value |
|---|---|---|
| Thermal Conductivity | W/(m·K) | 170–230 |
| Coefficient of Thermal Expansion | 10⁻⁶/K | 4.6–5.7 |
| Dielectric Constant (1 MHz) | — | 8.5–9.0 |
| Volume Resistivity (25 °C) | Ω·cm | >10¹³ |
| Breakdown Strength | kV/mm | ≥15 |
| Flexural Strength | MPa | 350–450 |
| Density | g/cm³ | 3.25–3.32 |
| Typical Thickness Range | mm | 0.25–1.0 (custom on request) |
| Surface Roughness (Ra) | μm | ≤0.4 (polished) |
| Flatness / Dimensional Tolerance | — | ±0.1 mm (standard) |
Customization available: thickness, size up to 200 mm, polished or lapped surfaces, metallization layers (Cu, Mo, Au, Ni).
Key Properties of AlN Substrates
| Property | AlN Substrate | Al2O3 (Alumina) | Si3N4 | Diamond |
|---|---|---|---|---|
| Thermal Conductivity (W/m·K) | 170–230 | 20–30 | 80–100 | 1000–2200 |
| Electrical Resistivity (Ω·cm) | 10^14 | 10^14 | 10^14 | 10^16 |
| CTE (×10⁻⁶/°C) | 4.5–5.5 | 7–8 | 3–3.5 | 1–2.5 |
| Flexural Strength (MPa) | 300–400 | 300–350 | 600–800 | 400–500 |
| Density (g/cm³) | 3.26 | 3.90 | 3.18 | 3.52 |
Non-negotiable specs for industrial use:
Purity ≥99.5% to avoid metal ion contamination.
TTV (Total Thickness Variation) ≤5 µm for uniform bonding.
Compatible with DBC (Direct Bonded Copper) or AMB (Active Metal Brazing) metallization (Cu, Ag, Au).
Applications and Engineering Insights
1. Power Electronics: Mitigating Thermal Runaway in High-Voltage Modules
The fundamental challenge in modern power electronics, from EV inverters to industrial drives, is not just dissipating heat, but preventing thermal runaway. Our AlN substrates are a critical component in this fight. The excellent thermal conductivity (up to 230 W/m·K) ensures a low thermal resistance path, but it’s the precisely matched CTE that’s the real game-changer. It minimizes mechanical stress at the SiC/GaN-AlN interface, a key failure point, especially under rapid temperature cycling.
Our Insight: We’ve found that for every 10 °C reduction in junction temperature (), the component lifetime can be extended by up to 2x. Through our thermal simulation and design support, we help clients optimize the entire thermal stack—from the die-attach material to the baseplate geometry—to achieve this level of performance.
2. Semiconductor Manufacturing: Unlocking Precision and Yield
In the world of semiconductor manufacturing, precision is everything. AlN’s value here extends beyond simple heat transfer; it’s about thermal uniformity and process control.
Electrostatic Chucks (ESCs): We don’t just supply AlN for ESCs. We partner with clients to engineer custom chucks that leverage AlN’s high dielectric strength and thermal uniformity. This enables highly stable clamping and precise temperature control, with a TTV (Total Thickness Variation) of less than 3 µm across a 12-inch wafer, which is essential for maximizing process yield in complex photolithography and plasma etching steps.
Unique Solution: For high-frequency plasma etching, we’ve developed specialized AlN plates with embedded RF channels, providing a stable platform that maintains signal integrity and reduces energy loss.
3. 5G & RF Communications: Ensuring Signal Integrity and High-Frequency Performance
The dense integration of RF power amplifiers in 5G massive MIMO antennas presents a dual challenge: heat and signal loss. While AlN’s thermal conductivity addresses the heat, its low dielectric loss is what truly sets it apart for these applications.
Our Insight: Our specialized HTCC (High-Temperature Co-Fired Ceramic) AlN substrates allow for the integration of 3D circuits and complex internal wiring. This enables the creation of highly compact and efficient RF packages that not only manage heat but also minimize signal interference and cross-talk, which are critical for high-frequency performance and ensuring network uptime.
4. Advanced Optoelectronics: Maximizing Light Output and Lifespan
For high-power LEDs and laser diodes, the primary cause of degradation is heat. Our AlN solutions are not just heatsinks; they are engineered platforms that optimize light output.
Flip-Chip and COB Modules: We work with manufacturers to design AlN substrates that provide a low-resistance thermal path from the back of the die, enabling higher lumen densities without sacrificing lifespan.
Unique Solution: We supply ultra-flat, optically polished AlN substrates for UV-C LEDs that not only dissipate heat but also act as a reflective surface to maximize light output, improving overall system efficiency. This is a unique application that requires a deep understanding of both thermal and optical properties.
Advanced Manufacturing & Metallization Services
Supwafer uses state-of-the-art sintering (including hot-pressing and sintering aids such as Y₂O₃ and CaO) to achieve high density and ultra-high thermal conductivity.
How to Choose the Right AlN Substrate?
Define Thermal Demand: Calculate heat flux (W/cm²). SiC modules typically need ≥180 W/m·K, while LEDs can operate with 150–170 W/m·K.
Size & Thickness: Choose standard 2–12 inch sizes. Use ultra-thin (0.1 mm) for portable electronics, or thick (3 mm) for structural support.
Metallization & Finish: Use Cu for high current, Au for corrosion resistance, and Ag for cost-sensitive designs.
Request Samples & Testing: Insist on lab data, including laser flash thermal conductivity, TTV measurement, and reflow solderability tests.
Why Choose Us?
When your high-performance design depends on reliability, you need more than just a supplier; you need a dedicated technical partner. We are committed to providing AlN substrates that meet the most demanding industrial standards. Our team offers deep technical expertise and end-to-end support, from initial thermal simulations to final product delivery.
We maintain a rigorous quality control process, ensuring every substrate meets precise specifications for purity, TTV, and surface finish. We are a trusted partner for clients in power electronics, semiconductor manufacturing, and communications, providing not just products but reliable solutions engineered for success.
Faqs:
1. What is an Aluminum Nitride (AlN) substrate?
An AlN substrate is a high-performance technical ceramic (AlN = AlN, aluminum nitride) used as an electrically insulating but highly thermally conductive base for electronic components and power modules. It combines high thermal conductivity, good mechanical strength and electrical insulation, making it ideal for heat-dissipating substrates and high-reliability packages.
2. What thermal conductivity can I expect from AlN?
Commercial AlN substrates are typically specified in ranges such as ~170–230 W/(m·K) for high-grade, low-oxygen materials. Exact values depend on purity and sintering process (hot-pressed grades often reach the top of this range).
3. How well does AlN match silicon thermally (CTE)?
AlN’s coefficient of thermal expansion (CTE) is ~4.3–5.5 ×10⁻⁶/K (depending on direction and grade), which is close to silicon’s CTE—this reduces thermomechanical stress in chip-to-substrate joints and improves reliability in power modules.
4. How does AlN compare with alumina (Al₂O₃)?
AlN offers much higher thermal conductivity (typical ~170–230 W/m·K) versus alumina’s ~20–30 W/m·K, and a closer CTE match to Si. The trade-off is cost: AlN is significantly more expensive than standard alumina, so choose AlN when thermal performance justifies the premium.
5. Is Aluminum Nitride toxic / safe to handle?
Bulk AlN ceramic is not highly toxic, but powder and dust (during machining, grinding or thermal decomposition) can irritate lungs and must be controlled—use dust/ventilation controls and PPE. MSDS documents warn against inhalation of dust and advise standard handling controls.
6. How are AlN substrates manufactured (main processes)?
Common manufacturing routes include hot-pressing, pressureless sintering (with sintering aids such as Y₂O₃ or CaO) and HTCC (high-temperature co-fired) for multilayer parts. Process choice affects density, oxygen content and final thermal conductivity.
7. Can AlN substrates be metallized for soldering or DBC?
Yes. AlN can be metallized (e.g., Mo-Mn + Ni/Au systems, copper sputter/bonding, or DBC/AMB processes) to create robust copper-bonded or plated surfaces suitable for soldering and power interconnects. Different metallization routes suit different current loads and processing flows.
8. What sizes and thicknesses are commonly available?
Stock AlN panels/plates and substrates commonly range from small coupons (tens of mm) up to standard panel sizes and custom plates; in electronics typical thicknesses range from ~0.25 mm to several mm. Suppliers also offer custom shapes, drilled features and thin sheets for PCB/SiP uses. (Lead times and MOQ vary by supplier.)
9. Are AlN substrates suitable for SiC / GaN power modules?
Yes—because of their high thermal conductivity and favorable CTE match, AlN is widely used in SiC and GaN power modules, where rapid heat removal and mechanical stability under thermal cycling are critical.
10. What is the maximum operating temperature for AlN substrates?
Aluminum nitride (AlN) substrates can withstand very high temperatures. Under certain controlled conditions they can operate up to approximately 1,370 °C without significant degradation.
11. Can AlN substrates be customized in size, shape or metallization?
Yes. Many manufacturers offer custom dimensions, thicknesses, drilled holes, edge treatments and metallization options such as direct-bonded copper (DBC) or other coatings to meet specific application requirements.
12. Is aluminum nitride toxic?
In its solid form, AlN is generally considered non-toxic. However, inhaling fine AlN dust can irritate the respiratory tract, so proper safety precautions such as dust masks or extraction systems should be used during machining or grinding.
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