Since 2023, the global market size of aluminum nitride has reached 151.5 million US dollars, and it is expected to continue to grow from 2024 to 2032, from 159.8 million US dollars to 246.5 million US dollars. This shows the importance of aluminum nitride as an advanced material.
Do you have some knowledge of aluminum nitride ceramics? In this article, we will lead you to fully understand the key characteristics and application value of aluminum nitride ceramics.
Quick Links
- Introduction To Aluminum Nitride Ceramics
- Aluminum Nitride Ceramic Performance Properties
- Aluminum Nitride Manufacturing Process
- Application Of Aluminum Nitride Ceramics
- How To Choose Aluminum Nitride Products?
If you don’t have time to read a lot of copy, we have prepared some common questions from other users for you, hoping to help you.
Introduction To Aluminum Nitride Ceramics
What Is Aluminum Nitride Ceramic?
Aluminum nitride ceramics are made of aluminum nitride, which is a high-performance non-oxide ceramic material composed of aluminum and nitrogen elements, and its chemical formula is AlN.
Aluminum nitride ceramics have very excellent physical and chemical properties, and its color in practical applications is usually off-white or light yellow.
Aluminum Nitride Ceramics
The Importance of Aluminum Nitride Ceramics in Modern Industry
Perhaps you will find that aluminum nitride ceramics can be seen in many places in daily life. Yes, aluminum nitride ceramics play an indispensable role in modern industry.
As a high-performance electronic ceramic material, aluminum nitride ceramics are usually widely used in various fields such as semiconductor manufacturing, LED packaging, high-power electronic devices, and aerospace.
The thermal conductivity of aluminum nitride can be higher than 170W/mK, and it also has excellent insulation properties. Due to the combination of these two properties, its effect in achieving electronic heat dissipation and insulation is even more significant!
It is worth noting that compared with aluminum oxide (Al2O3), which is also a ceramic material, the thermal conductivity of aluminum nitride is much higher than 5 times; on the other hand, compared with toxic beryllium oxide (BeO), nitride Aluminum not only maintains similar thermal conductivity, but also overcomes the toxicity problem. To sum up, we can see the superiority and reliability of aluminum nitride in modern industry!
Aluminum Nitride Ceramic Performance Properties
The following are some properties of aluminum nitride ceramics for your reference:
|
Performance Category |
Performance Indicators |
Parameter Value |
Unit |
|
Thermal Properties |
Thermal Conductivity(25℃) |
170-321 |
W/(m·K) |
|
Thermal Expansion Coefficient (25-400℃) |
4.5 |
×10⁻⁶/℃ |
|
|
Maximum Operating Temperature (Inert gas) |
2200 |
℃ |
|
|
Oxidation Onset Temperature (air) |
700 |
℃ |
|
|
Electrical Properties |
Volume Resistivity (25℃) |
＞1014 |
Ω·cm |
|
Dielectric Constant Speed (1MHz) |
8.5-9.0 |
– |
|
|
Dielectric Loss (1MHz) |
0.0005 |
– |
|
|
Breakdown voltage Strength |
15-20 |
kV/mm |
|
|
Mechanical Properties |
Density |
3.26 |
g/cm³ |
|
Vickers Hardness |
12 |
GPa |
|
|
Bending Strength |
350-420 |
MPa |
|
|
Elastic Modulus |
320 |
GPa |
|
|
Poisson’s Ratio |
0.22 |
– |
|
|
Compressive Strength |
3000 |
MPa |
Thermal Properties
Thermal Conductivity：
The most notable feature of aluminum nitride ceramics is its excellent thermal conductivity. Under normal temperature conditions, its thermal conductivity can reach 321 W/(m·K), and in actual applications, the thermal conductivity of polycrystalline aluminum nitride ceramics can usually exceed 170 W/(m·K). For this excellent performance, it far exceeds that of alumina ceramics.
Coefficient Of Thermal Expansion：
The thermal expansion coefficient of aluminum nitride ceramics is also worthy of your attention. Its thermal expansion coefficient is compatible with silicon. The thermal expansion coefficient of aluminum nitride in the range of 25-400℃ is 4.5×10-6/℃, while the thermal expansion coefficient of silicon It is 3.5-4×10⁻⁶/℃. A comparison between the two shows that they are very close. Therefore, with this excellent matching performance, stress accumulation during thermal cycling can be effectively reduced, thereby significantly increasing the service life of electronic equipment.
Thermal Stability：
In terms of thermal stability, aluminum nitride ceramics still have excellent performance and have extremely high heat resistance. In an inert atmosphere, it can remain stable at a high temperature of 2200°C. Even in air, surface oxidation will not begin to occur until the temperature is above 700°C, and the surface oxide layer can in turn protect the internal material until 1370°C.
Electrical Properties
Electrical Insulation：
When you are choosing the right electronic ceramic material, electrical properties are a key factor that cannot be ignored. Aluminum nitride has extremely excellent electrical insulation properties, and its volume resistivity can reach more than 10¹⁴ Ω·cm at room temperature. This high insulation performance can fully ensure that aluminum nitride has extremely high reliability in high-voltage electronic device applications.
Dielectric Constant/Dielectric Strength：
The dielectric constant of aluminum nitride is about 8.5-9 (1MHz) and the dielectric loss is about 0.0005. These characteristics make it an ideal choice for high-frequency electronic devices. At the same time, the dielectric strength of aluminum nitride can reach 15-20 kV/mm, which effectively improves the insulation protection capability.
Mechanical Properties
Aluminum nitride ceramics also have various excellent mechanical properties. Its Vickers hardness is about 12GPa and its bending strength can reach 350-420MPa. These excellent mechanical strengths are much higher than those of alumina ceramics, allowing it to maintain good reliability in harsh environments.
Corrosion Resistance
In terms of durability, aluminum nitride exhibits excellent resistance to chemical corrosion. In the face of corrosion by most molten metals (such as copper, lithium, aluminum, etc.), aluminum nitride performs well, and this property enables it to maintain good stability even in harsh chemical environments.
It is worth mentioning that aluminum nitride also has excellent fatigue resistance. In a high-temperature environment, the strength attenuation of aluminum nitride is only about 20% of the room temperature strength. Compared with ordinary alumina, alumina usually loses 50% of its strength under the same circumstances.
Aluminum Nitride Manufacturing Process
Are you curious about how aluminum nitride ceramics are manufactured? The manufacturing process of aluminum nitride ceramics directly affects its final performance. Below we will take you to a deeper understanding of several key steps in the manufacture of aluminum nitride.
Aluminum Nitride Powder Synthesis
Aluminum nitride powder synthesis is the basis of the entire manufacturing process. There are two main methods currently used: carbothermal reduction and direct nitridation.
The carbothermal reduction method is to react alumina with carbon in a nitrogen atmosphere at 1500-1800°C. This method is relatively low-cost and suitable for large-scale production.
The direct nitridation method is to allow metallic aluminum powder to react directly with nitrogen. This method can obtain a product with higher purity.
Molding Process
Molding is a key step in determining the final shape of ceramics. The main molding methods include dry pressing, injection, isostatic pressing, etc.
Dry Press Molding：This molding method is suitable for ceramic products with simple shapes, such as substrates and substrates. By uniformly pressurizing aluminum nitride powder, it is made into the desired shape.
Injection Molding：This molding method is suitable for manufacturing parts with complex shapes. It is necessary to mix aluminum nitride powder with an organic binder to form a slurry and inject it into the mold for molding.
Isostatic Pressing Molding：This molding method is suitable for manufacturing large-sized and regular-shaped ceramic products. Through hydraulic isostatic pressing, it can ensure uniform product density.
Sintering Process
Sintering is a very important step in the ceramic manufacturing process and is also a key process for improving aluminum nitride ceramics. Due to the covalent bond characteristics of aluminum nitride, special process control is required during the sintering process. Hot pressing sintering and pressure-assisted two-step sintering are often used.
If an appropriate amount of yttrium oxide (Y₂O₃) is added as a sintering aid, the sintering temperature can be significantly reduced and the material density can be increased. The optimal sintering temperature is generally controlled in the range of 1650-1800℃.
Precision Machining
The processing of aluminum nitride ceramics needs to take into account the high hardness characteristics of the material, and currently diamond tools are mainly used for precision processing.
Green Processing：Preliminary shaping of the material before sintering can significantly reduce the difficulty of subsequent processing
Grinding Polishing：Precision grinding with diamond grinding wheels ensures perfect surface quality
Laser Cutting：For thin sheets, laser technology can be used for precise processing
Quality Control
Strict quality control ensures that the aluminum nitride ceramics produced
To ensure the stable performance of aluminum nitride ceramics, comprehensive quality control needs to be implemented during the manufacturing process：
Process control：Multiple detection points can be set in key processes such as synthesis and sintering to monitor process parameters in real time，such as：
Temperature curve monitoring
Atmosphere component control
Pressure parameter adjustment
Finished product inspection：Comprehensive quality assessment of finished products using advanced inspection equipment，such as：
Thermal conductivity test
Density determination
Microstructure analysis
Mechanical performance testing
Application Of Aluminum Nitride Ceramics
Electronics Industry
In the field of electronics industry, aluminum nitride ceramics shine with their excellent performance characteristics.
In the design of heat dissipation substrates, the thermal conductivity of aluminum nitride ceramic substrates exceeds 170W/mK, which is much higher than other ceramic materials (such as alumina substrates). This excellent thermal conductivity enables it to quickly disperse and conduct the heat generated by electronic devices, effectively preventing local overheating and improving the stability and service life of the equipment.
In terms of power device packaging, aluminum nitride ceramics are also particularly critical. If you have related aluminum nitride ceramic products around you, you will find that it not only has excellent heat dissipation performance but also has a thermal expansion coefficient similar to that of silicon wafers. This matching significantly reduces the generation of thermal stress and can greatly improve the reliability of ceramic packaging. At the same time, the excellent electrical insulation also ensures the safe operation of the power device.
Semiconductor Industry
In the semiconductor manufacturing process, aluminum nitride ceramics play an indispensable role.
The wafer processing process requires extremely precise temperature control. The high thermal conductivity and temperature uniformity of aluminum nitride ceramics ensure the stability of the processing process and the quality of the product.
Electrostatic chuck is a key device in the semiconductor manufacturing process. The excellent dielectric properties and mechanical strength of aluminum nitride ceramics make it an ideal material for electrostatic chucks. It can still maintain stable electrical properties in high temperature environments, and it also has sufficient mechanical strength to be used repeatedly.
In high-frequency devices, the low dielectric loss and thermal management capabilities of aluminum nitride ceramics make it an ideal packaging material. You can find it in microwave communications and radio frequency devices.
Other High-End Applications
In the application of optoelectronic products, aluminum nitride ceramics can not only be used as heat dissipation substrates for laser devices, but can also be used as dielectric layers for optical storage media.
The aerospace industry is extremely demanding in the selection of materials. Aluminum nitride is widely used in a variety of important fields such as aerospace electronic equipment and satellite communications due to its high temperature stability, insulation and excellent mechanical strength.
In the military field, aluminum nitride is also very important. From the heat dissipation components of radar systems to the key components of navigation equipment, aluminum nitride ceramics play an important role. Its excellent comprehensive performance can ensure that military equipment can be used stably even in extremely harsh environments.
In the field of military industry, the application of aluminum nitride ceramics is also very important. From the heat dissipation components of radar systems to the key components of navigation equipment, aluminum nitride ceramics play an important role. Its excellent comprehensive performance ensures the reliable operation of military equipment in extreme environments.
How To Choose Aluminum Nitride Products?
If you need aluminum nitride products but don’t know how to choose, then the following content can help you.
Aluminum Nitride Substrate Selection
If you need an aluminum nitride substrate, you can refer to the following key parameters.
The standard substrate thickness range is usually between 0.25mm and 2.0mm, and the area can reach 150mm×200mm.
Depending on the application requirements, you can choose different grades of substrates with thermal conductivity ranging from 170 W/mK to 230 W/mK.
The surface roughness is controlled within Ra 0.3-0.5μm, and the flatness is controlled within 2% per millimeter.
To ensure your application is met, we recommend you focus on the following parameter specifications：
Dimensional Tolerance：It is best to control it within ±0.1mm
Thickness Uniformity：The standard deviation does not exceed 5%
Metallization Compatibility：Depending on your application, you can choose from different metallization options such as tungsten or molybdenum
Surface Treatment：Polishing, sandblasting and other treatment methods can be selected according to needs
Cooling Component Selection
When choosing a suitable heat dissipation component, you need to consider the heat dissipation requirements and installation space.For high power applications, we recommend that you choose products with a thermal conductivity above 200 W/mK.If you have higher requirements for heat dissipation, you can optimize the heat conduction efficiency by adding thermal paste or thermal pads.
Customized Solution Suggestions
We recommend that you choose a customized solution based on your application scenario. The key points you need to pay attention to are:
Clarify the working environment temperature range
Clarify maximum power density requirements
Clarify installation space restrictions
Clarify cooling system integration requirements
If you need help, please provide us with detailed application parameters and we can customize the most optimized solution for you, including material selection, structural design and surface treatment, etc. Contact us now.
Cost Effective
The cost of aluminum nitride ceramic products is mainly affected by the following factors：
Material grade：The higher the thermal conductivity you choose, the higher the cost.
Processing accuracy：The higher the precision requirement you choose, the higher the processing cost.
Batch size：If you produce in large quantities, you can significantly reduce the unit cost.
To help you achieve the best cost-benefit ratio, we recommend：
Low power applications，It is recommended that you choose a standard 170 W/mK grade product, which can meet your basic needs while also controlling costs.
Medium power applications，It is recommended that you choose a 200 W/mK grade product, which strikes a balance between performance and cost.
High power applications，It is recommended that you choose 230 W/mK grade products. Although its initial cost is higher, it can provide the best heat dissipation performance and extend the life of the equipment, effectively reducing your overall operating costs.
Conclusion
Aluminum nitride ceramics are ideal materials for many industries. Thank you for reading and hope it can help you.
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FAQs.
1.What is the chemical formula of Aluminum Nitride (AlN)?
The chemical formula of aluminum nitride is AlN, which is composed of aluminum (Al) atoms and nitrogen (N) atoms in a stoichiometric ratio of 1:1. In its structure, aluminum and nitrogen form a covalent bond, and it is a stable crystalline compound with a wurtzite structure.
2.What is the thermal conductivity of Aluminum Nitride ceramic?
Aluminum nitride ceramics have excellent thermal conductivity at room temperature, about 170-321 W/(m·K), and the theoretical maximum thermal conductivity is 321 W/(m·K). The polycrystalline AlN you see on the market can usually reach values above 170 W/(m·K), which is more than five times higher than aluminum oxide.
3. What are the performance differences between Aluminum Nitride and Aluminum Oxide (Al₂O₃)?
Aluminum nitride outperforms aluminum oxide in several key performance aspects. The thermal conductivity of AlN (>170 W/m·K) is five times higher than that of aluminum oxide (20-30 W/m·K).
Aluminum nitride has better thermal shock resistance than aluminum oxide and its thermal expansion coefficient is better matched to silicon.
But for applications where high thermal conductivity is not important, aluminum oxide can significantly help you save money.
4. What is the melting point of Aluminum Nitride ceramic?
The melting point of aluminum nitride in an inert gas is about 2200°C. However, you need to be aware that in a vacuum environment, aluminum nitride will begin to decompose at 1800°C.
In air, the surface of aluminum nitride will begin to oxidize at 700°C, forming a protective layer that can protect the internal material from remaining stable before 1370°C.
5. What are the standard thickness specifications for Aluminum Nitride substrates?
The thickness of standard aluminum nitride substrates ranges from 0.25-2.0mm. In addition, common specifications include 0.25mm, 0.38mm, 0.63mm and 1.0mm, and the dimensional tolerance is usually controlled within ±0.1mm.
You can customize the thickness according to specific application requirements, and the surface roughness is best maintained at Ra 0.3-0.5μm.
6. What is the dielectric constant of Aluminum Nitride ceramic?
The dielectric constant of aluminum nitride ceramics is 8.5-9.0 at 1MHz.
7. How well does the thermal expansion coefficient of Aluminum Nitride match with Silicon?
The thermal expansion coefficient of aluminum nitride is very well matched to that of silicon. The thermal expansion coefficient of aluminum nitride is 4.5×10⁻⁶/℃, while the thermal expansion coefficient of silicon is 3.5-4×10⁻⁶/℃, which is very close. This matching reduces thermal stress in semiconductor applications, making aluminum nitride an ideal substrate material for silicon-based devices, which can greatly reduce the risk of cracking during thermal cycling.
8. How good are the insulation properties of Aluminum Nitride ceramic?
Aluminum nitride ceramics have excellent insulation properties. At room temperature, its volume resistivity exceeds 10¹⁴ Ω·cm. In addition, it maintains a high dielectric strength of 15-20 kV/mm, making it an excellent insulator.
9. What are the typical applications of Aluminum Nitride ceramic substrates?
Aluminum nitride ceramic substrates can be used in multiple industries. You can use it in the field of power electronics as a heat dissipation substrate for high-power and IGBT modules; or in the LED industry, use them as thermal management materials for high-brightness LEDs; or in semiconductor industry wafer processing equipment and RF/microwave components; in addition, the application of aluminum nitride substrates is also very important in some aerospace and military fields.
10. Is Aluminum Nitride an ionic or covalent compound?
Aluminum nitride is a covalent compound. Its characteristic is that there is a strong covalent bond between aluminum atoms and nitrogen atoms. This structure gives aluminum nitride high thermal conductivity and excellent mechanical strength. But you need to know that the obvious electronegativity difference between aluminum atoms and nitrogen atoms leads to some polar characteristics, although the overall bonding is still mainly covalent.
11. What is the mechanical strength of Aluminum Nitride ceramic?
Aluminum Nitride ceramic demonstrates impressive mechanical properties with a flexural strength of 350-420 MPa and a compressive strength of approximately 3000 MPa. The material exhibits a Vickers hardness of 12 GPa and Young’s modulus of 320 GPa. These mechanical properties ensure reliable performance in demanding applications, particularly when subjected to thermal and mechanical stress cycles.
12. What are the advantages of Aluminum Nitride ceramic in LED packaging?
The main advantages of aluminum nitride are: excellent thermal conductivity can effectively dissipate the heat generated by high-power LEDs; electrical insulation can ensure safe operation; and the thermal expansion coefficient matches that of semiconductor materials to reduce thermal stress.
13. What advantages does Aluminum Nitride have over Beryllium Oxide (BeO)?
The thermal properties of aluminum nitride are comparable to those of beryllium oxide, and aluminum nitride is completely non-toxic. Beryllium oxide is highly toxic when processed or handled, so aluminum nitride will be more cost-effective in large-scale production applications.
14. What surface treatment processes are available for Aluminum Nitride ceramic?
Surface treatment processes for aluminum nitride ceramics include precision grinding, diamond polishing, and various metalworking processes.
Surface finishing can achieve a roughness value of Ra 0.3-0.5μm; while metallization includes tungsten, molybdenum, and copper patterns for electrical connections; special treatment processes include enhancing surface wettability, improving adhesion of thermal interface materials, etc.