Silicon Nitride vs. Aluminum Nitride Which is the Most Promising Substrate Material?

With the rise and application of power devices, especially third-generation semiconductors, semiconductor devices are gradually evolving toward high power, miniaturization, integration, and multifunctionality. This places higher demands on the performance of packaging substrates. Ceramic substrates, with their high thermal conductivity, excellent heat resistance, low thermal expansion coefficient, high mechanical strength, good insulation, corrosion resistance, and radiation resistance, are widely used in electronic device packaging.

So, between aluminum nitride (AlN) and silicon nitride (Si₃N₄), which is the most promising packaging material?

 

Juci AlN powder

 

Requirements for Ceramic Substrate Materials

1、High thermal conductivity to meet heat dissipation needs.

2、Excellent heat resistance for high-temperature applications (above 200°C).

3、Matching thermal expansion coefficient to reduce thermal stress between the chip and substrate.

4、Low dielectric constant for high-frequency performance, reducing signal delay and improving transmission speed.

5、High mechanical strength to withstand mechanical demands during packaging and application.

6、Good corrosion resistance to endure strong acids, alkalis, boiling water, and organic solvents.

7、Dense structure to meet hermetic packaging requirements for electronic devices.

 

Silicon Nitride (Si₃N₄)

Si₃N₄ ceramic substrates have an elastic modulus of 320 GPa, a flexural strength of 920 MPa, a thermal expansion coefficient of only 3.2 × 10⁻⁶/°C, and a dielectric constant of 9.4. They exhibit high hardness, strength, low thermal expansion, and excellent corrosion resistance.

Initially, due to the complex crystal structure of Si₃N₄, which causes significant phonon scattering, its thermal conductivity was considered low (15–30 W/(m·K)), making it suitable only for applications like bearing balls and structural components. However, research later revealed that the low thermal conductivity was mainly due to lattice defects and impurities, and it was predicted that its theoretical thermal conductivity could reach up to 320 W/(m·K). Subsequent studies optimized the manufacturing process, significantly improving the thermal conductivity of Si₃N₄ ceramics, which has now reached 177 W/(m·K).

Additionally, compared to other ceramic materials, Si₃N₄ exhibits outstanding advantages, particularly in high-temperature environments, where it demonstrates excellent thermal stability, chemical inertness to metals, ultra-high hardness, and fracture toughness. The flexural strength and fracture toughness of Si₃N₄ ceramics are more than twice those of AlN, making Si₃N₄ substrates far superior in reliability.

 

Aluminum Nitride (AlN)

AlN is one of the few materials that combines high thermal conductivity with excellent electrical insulation.

Its advantages include:

High thermal conductivity—Theoretical thermal conductivity at room temperature can reach up to 320 W/(m·K), 8–10 times that of alumina ceramics. In practice, its thermal conductivity can reach 200 W/(m·K), facilitating heat dissipation in LEDs and improving performance.

Low thermal expansion coefficient—Theoretical value is 4.6 × 10⁻⁶/K, close to that of commonly used LED materials like Si and GaAs. Its thermal expansion behavior is also similar to that of Si. Additionally, AlN has a lattice structure matching that of GaN, which is crucial for high-performance power LEDs.

Wide bandgap (6.2 eV)—Excellent insulation properties eliminate the need for additional insulation treatment in high-power LED applications, simplifying the process.

High hardness and strength—Due to its wurtzite structure and strong covalent bonds, AlN exhibits good mechanical properties. It also has excellent chemical stability and high-temperature resistance, remaining stable in air up to 1000°C and in vacuum up to 1400°C, making it suitable for high-temperature sintering and corrosion-resistant applications.

 

Juci AlN substrates

 

Conclusion

Among existing ceramic substrate materials, Si₃N₄ has the highest flexural strength and wear resistance, making it the best in terms of comprehensive mechanical properties. Its extremely low thermal expansion coefficient also makes it a highly promising material for power device packaging. However, its complex manufacturing process, high cost, and relatively low thermal conductivity limit its use to applications requiring high strength but moderate heat dissipation.

On the other hand, AlN excels in almost all aspects, particularly in thermal conductivity, which is crucial for electronic packaging. The main drawback is its high cost due to expensive raw materials and processing. However, as AlN production technology advances, costs are expected to decrease, paving the way for widespread adoption in high-power LED applications.

Which material do you think will dominate the future of high-power electronics?

 

About Xiamen Juci Technology

As the top aluminum nitride (AlN) powder manufacturer in China, Xiamen Juci Technology specializes in high-purity, high-performance AlN materials for advanced electronic applications. Our AlN powder and ceramics deliver exceptional thermal conductivity (up to 200 W/m·K), superior electrical insulation, and outstanding mechanical strength, making them ideal for high-power electronics, semiconductor packaging, LED cooling, and next-generation 5G/EV systems.

 

Media Contact:
Xiamen Juci Technology Co., Ltd.

Phone: +86 592 7080230
Email: miki_huang@chinajuci.com

Website: www.jucialnglobal.com

What are the ways to increase the thermal conductivity of AlN?

Aluminum nitride (AlN) ceramics are widely used in electronic packaging and heat dissipation due to their excellent thermal conductivity. However, impurities and sintering conditions significantly affect their performance. This article discusses key approaches to improving AlN's thermal conductivity, including powder purification, sintering aids, process optimization, and prolonged sintering.

 

AlN heat sinks

 

(1) Controlling the Quality of AlN Powder and Reducing Oxygen Impurity Content

Improving the synthesis method of AlN powder to produce high-purity powder with a particle size below 1 μm and an oxygen content of 1% is a prerequisite for preparing high-thermal-conductivity AlN ceramics. Additionally, for AlN powder containing sintering aids, introducing an appropriate amount of carbon can reduce and carburize the oxides on the AlN powder surface during the sintering process before densification, thereby enhancing the thermal conductivity of AlN ceramics. From this perspective, AlN powder prepared by the carbothermal reduction method may be more conducive to improving the thermal conductivity of AlN ceramics.

(2) Selecting Appropriate Types and Amounts of Sintering Additives

Extensive research has shown that rare-earth metal oxides and fluorides, alkaline-earth metal oxides and fluorides, etc., can serve as sintering aids to improve the thermal conductivity of AlN. Sintering aids react with alumina in AlN to form aluminate liquid phases, facilitating liquid-phase sintering and densification of the green body. On the other hand, sintering aids can reduce the oxygen content in the AlN lattice while enhancing contact between AlN particles, thereby improving thermal conductivity. However, the amount of additives must be appropriate—excessive amounts increase impurity content and impair thermal conductivity, while insufficient amounts fail to serve as effective sintering aids. As mentioned earlier, recent studies have shown that composite additives are more effective than single additives in enhancing thermal conductivity while also lowering the sintering temperature.

The effectiveness of additives in improving thermal conductivity has been confirmed by numerous experiments. Introducing suitable additives is currently a widely adopted method. However, there is no unified conclusion regarding the selection and combination of additives, their optimal amounts, or the methods of addition, necessitating further in-depth and systematic exploration.

 

AlN substrats

 

(3) Optimizing Sintering Processes

For AlN ceramics, slow heating during sintering is more advantageous than rapid heating, as it not only reduces deformation but also improves the densification of the green body, thereby enhancing the performance of AlN ceramics.

The sintering process also involves an optimal sintering temperature. If the temperature is too high, excessive grain growth occurs, the grain boundary phase increases, and densification decreases, negatively impacting thermal conductivity.

Appropriately extending the sintering time can further purify the crystal lattice, promote grain growth, and significantly reduce porosity, thereby increasing thermal conductivity.

Generally, sintering in a reducing atmosphere under nitrogen protection can reduce oxygen impurities in AlN through carbothermal nitridation and reduction, which is beneficial for improving thermal conductivity. Pressure sintering significantly enhances the sintering performance of AlN and reduces the amount of sintering aids required. Increasing pressure improves the densification of AlN, all of which contribute to better performance of AlN ceramics. Additionally, the powder-bed method also affects the thermal conductivity of AlN ceramics.

(4) Prolonging Sintering Time

In addition to introducing sintering aids and optimizing sintering processes, extending the sintering time can also improve the thermal conductivity of AlN ceramics. For example, annealing in a reducing atmosphere can remove oxygen and secondary phases from AlN. Nakano et al. used a similar method, heat-treating sintered AlN (with Y₂O₃) in a reducing nitrogen atmosphere at 1900°C. After 20 hours, the thermal conductivity reached 220 W/m·K, and after 100 hours, it increased to 272 W/m·K.

 

AlN ceramics

 

About Xiamen Juci Technology

Juci Technology, with its high-purity raw materials, composite additive technology, precise sintering process and flexible customization capabilities, has become one of the few domestic enterprises capable of stably mass-producing high thermal conductivity AlN ceramics, especially suitable for the demands of high-end fields such as high-power leds, IGBT modules and aerospace.

 

Media Contact:
Xiamen Juci Technology Co., Ltd.

Phone: +86 592 7080230
Email: miki_huang@chinajuci.com

Website: www.jucialnglobal.com

 

In which fields are aluminum nitride (ALN) ceramics widely used?

Aluminum Nitride (AlN) possesses a series of excellent properties, with its core advantages including outstanding thermal conductivity, reliable electrical insulation, and a thermal expansion coefficient that matches silicon. In which fields can it be applied?

1、Heat Dissipation Substrates and Electronic Device Packaging

Heat dissipation substrates and electronic device packaging are the primary applications of AlN ceramics. AlN ceramics exhibit exceptional thermal conductivity, a thermal expansion coefficient close to that of silicon, high mechanical strength, good chemical stability, and are environmentally non-toxic. They are regarded as ideal materials for the next generation of heat dissipation substrates and electronic device packaging. They are particularly suitable for hybrid power switch packaging, microwave vacuum tube encapsulation shell materials, and are also an ideal substrate material for large-scale integrated circuits.

 

AlN ceramic substrates

 

2、Structural Ceramics

A common application of structural ceramics is in electrostatic chucks for wafer processing. AlN structural ceramics offer excellent mechanical properties, high hardness, and better toughness than Al₂O₃ ceramics, along with high-temperature and corrosion resistance. Leveraging AlN's heat and erosion resistance, it can be used to manufacture high-temperature corrosion-resistant components such as crucibles, Al evaporation dishes, and semiconductor electrostatic chucks.

3、Functional Materials

AlN can be used to produce high-frequency, high-power devices capable of operating in high-temperature or radiation-prone environments, such as high-power electronic devices and high-density solid-state memory. As one of the third-generation semiconductor materials, AlN boasts a wide bandgap, high thermal conductivity, high resistivity, excellent UV transmittance, and high breakdown field strength.

With a bandgap of 6.2 eV and strong polarization effects, AlN finds applications in mechanical, microelectronic, optical, and surface acoustic wave (SAW) device manufacturing, as well as high-frequency broadband communication. Examples include AlN piezoelectric ceramics and thin films. Additionally, high-purity AlN ceramics are transparent, offering excellent optical properties. Combined with their electrical properties, they can be used to create functional devices such as infrared radomes and sensors.

4、Inert Heat-Resistant Materials

As a heat-resistant material, AlN can be used for crucibles, protective tubes, casting molds, and more. AlN remains stable in non-oxidizing atmospheres up to 2000°C, making it an excellent high-temperature refractory material with strong resistance to molten metal erosion.

 

AlN crucible

 

5、Heat Exchange Components

AlN ceramics feature high thermal conductivity, low thermal expansion coefficient, and excellent thermal efficiency and thermal shock resistance, making them ideal materials for heat exchange and thermal shock resistance. For example, AlN ceramics can serve as heat exchanger materials for marine gas turbines and heat-resistant components in internal combustion engines. The superior thermal conductivity of AlN materials significantly enhances the heat transfer efficiency of heat exchangers.

6、Filler Materials

AlN exhibits excellent electrical insulation, high thermal conductivity, good dielectric properties, and compatibility with polymer materials, making it an outstanding additive for electronic polymer materials. It can be used as a filler for thermal interface materials (TIM) and flexible copper-clad laminate (FCCL) dielectric layers, widely applied as a thermal transfer medium in electronic devices to improve efficiency. Examples include filling gaps between CPUs and heat sinks, or acting as a thermal transfer medium in the fine gaps between high-power transistors, thyristors, and substrates.

 

AlN powder

 

About Xiamen Juci Technology

Xiamen Juci Technology is the leading AlN powder manufacture in China. Our  AlN products feature excellent thermal conductivity, electrical insulation, and mechanical strength, widely used in electronic packaging, semiconductors, LED heat dissipation, and other fields. Juci Technology specializes in manufacturing high-performance aluminum nitride heat sinks and aluminum nitride ceramic substrates, providing leading solutions for electronic heat dissipation.

 

Media Contact:
Xiamen Juci Technology Co., Ltd.

Phone: +86 592 7080230
Email: miki_huang@chinajuci.com

Website: www.jucialnglobal.com

Abstract Late treatment with alpha GPC for increasesing hippocampal neurogenesis and providing protection against epilepsy seizure-induced neuronal death and cognitive impairment

Choline alfoscerate (α-GPC; alpha GPC; L-alpha glycerylphosphorylcholine; CAS No.:28319-77-9) is common choline compound and acetycholine precursor in the brain, which has been shown to be effective in the treatment of Alzheimer’s disease and dementia. α-GPC has been shown to enhance memory and cognitive function in stroke and Alzheimer’s patients but currently remains untested in patients suffering from epilepsy. This study aimed to evaluate whether α-GPC treatment after seizure can ameliorate seizure -induced cognitive impairment and neuronal injury.

The potential therapeutic effects of α-GPC on seizure-induced cognitive impairment were tested in an animal model of pilocarpine-induced seizure. Seizures were induced by intraperitoneal injection of pilocarpine (25 mg/ kg) in male rats. α-GPC (250 mg/kg) was injected into the intramuscular space once daily for one or three weeks from immediately after seizure, or from 3 weeks after the seizure onset for 3 weeks. Here we found that immediate 1-week treatment of α-GPC showed no neuroprotective effects and neurogenesis. Immediate 3-week treatment of α-GPC showed neuroprotective effect but no effect on neurogenesis. To evaluate the effect of late treatment of α-GPC on cognitive impairment following seizure, rats were injected α-GPC from 3 weeks after seizure for 3 weeks and subjected to a water maze test. In the present study, we found that administration of αGPC starting at 3 weeks after seizure improved cognitive function through reduced neuronal death and BBB disruption, and increased neurogenesis. Therefore, α-GPC injection may serve as a beneficial treatment for

improvement of cognitive function in epilepsy patients.

 

Reference:

Late treatment with choline alfoscerate (L-alpha glycerylphosphorylcholine, α-GPC) increases hippocampal neurogenesis and provides protection against seizure-induced neuronal death and cognitive impairment

Song Hee Lee, Bo Young Choi, Jin Hee Kim, A.Ra Kho, Min Sohn, Hong Ki Song,Hui Chul Choi
, Sang Won Suha
Department of Physiology, Hallym University, College of Medicine, Chuncheon, Republic of Korea
Department of Neurology, Hallym University, College of Medicine, Chuncheon, Republic of Korea

Inha University, Department of Nursing, Incheon, Republic of Korea
Hallym Institute of Epilepsy Research, Hallym University, College of Medicine, Chuncheon, Republic of Korea

 

Sinoway is a professional alpha-GPC supplier, we can supply you alpha GPC with 99.7% up, single impurity below 0.1%, Food Grade, Pharma Grade, 100% pass 80 mesh. Please feel free to contact china-sinoway for the more details.

 

Phenylmethane Bismaleimide (BMI-200) – Technical Datasheet

Phenylmethane bismaleimide BMI-200 (Other name:BMI-2300) ,CAS 67784-74-1) manufactured by Yangchen Tech is a high-performance thermoset resin for demanding aerospace, electronics, adhesives and composite applications. It is an aromatic bismaleimide (BMI) resin known for its excellent thermal stability, mechanical strength and chemical resistance. BMI-200 is typically supplied as a tan crystalline powder and cures to form a hard glassy network with a very high glass transition temperature (typically >250°C) and very low volatile by-products.

 

Phenylmethane bismaleimide

Physical Properties