Silicon Nitride Ceramics (chemical formula Si₃N₄) is a typical new type of inorganic non-metallic material, which belongs to high-performance structural ceramics.
It is formed by high temperature reaction between silicon and nitrogen, and has extremely high covalent bonding strength, which makes it simultaneously lightweight, high strength, high hardness, wear-resistant, thermal shock-resistant, and excellent electrical insulation properties.

For engineers, it is crucial to understand “what kind of material is silicon nitride”. Silicon nitride is a ceramic material dominated by covalent bonding. It is chemically stable and maintains its structure and properties even at high temperatures above 1200°C, and is therefore used in a wide range of high-end fields such as machinery, electronics, energy, and semiconductors.

Silicon Nitride ceramics are the same as silicon carbide, alumina, and aluminum nitride. Silicon nitride ceramics and silicon carbide, alumina, aluminum nitride and other new inorganic non-metallic materials, collectively referred to as “advanced ceramics” or “special ceramics”.
These materials differ from traditional ceramics in that they are formed through precision powder preparation and high-temperature sintering, and have a controlled microstructure and excellent mechanical and functional properties.

Correspondingly, boron nitride ceramics also belong to the new inorganic non-metallic materials, just boron nitride is more inclined to functional ceramics, while silicon nitride has both structural and functional characteristics, especially suitable for high-temperature stress and thermal shock of the engineering environment.

From the application point of view, silicon nitride ceramics belong to the composite type of structural ceramics and functional ceramics at the same time.

• As a structural ceramic, it can withstand high loads and extreme temperatures, and is commonly used in highly stressed parts such as engine impellers, bearing balls, and cutting tools;

• As a functional ceramic, its high thermal conductivity and electrical insulation properties make it an ideal material for electronic packaging and power module substrates.

This explains the popularity of silicon nitride ceramics in high-tech manufacturing across three industries: mechanical, electronics and semiconductor.

Silicon nitride ceramics typically have a density of 3.2 g/cm³, which is only 40% of steel and lighter than alumina. The lightweight properties make it an ideal alternative to metallic materials for structural weight reduction.

Silicon nitride has a thermal conductivity in the range of 20-90 W/m-K, which can be adjusted by adding oxide additives or controlling grain size.
High Thermal Conductivity Silicon Nitride Ceramic Substrate (High Thermal Conductivity Si₃N₄ Substrate) excels in electronic packaging, combining the advantages of both thermal conductivity and insulation.

These parameters determine the wide applicability of silicon nitride in high-temperature mechanical parts and electronic carriers.

The preparation process of silicon nitride ceramics directly determines its performance and cost. Currently common processes include:

1. General Pressure Sintering (GPSN): suitable for mass production and lower cost;

2. Hot Press Sintering (HPSN): High densities and strengths for high-end structural components;

3. HIP: Improvement of grain bonding, thermal conductivity and strength through high pressure of nitrogen;

4. Reaction sintering (RBSN): low cost, suitable for large size products.

Hot-press sintered silicon nitride ceramics are now widely used in high-precision mechanical bearings, cutting tools, turbine components, etc. And with the development of silicon nitride ceramic precision machining technology, the manufacturing accuracy of complex shapes and microfabricated parts is constantly improving.

Silicon nitride ceramic balls are one of the most representative applications on the market.
Compared with steel balls, it has the advantages of high hardness, low density, resistance to wear, corrosion and thermal expansion.

Uses and characteristics of silicon nitride ceramic balls:

• Used for high speed bearings, vacuum pumps, aviation turbines, precision ball screws;

• Long-term operation in vacuum, corrosive media and high temperature environments is possible;

• Low coefficient of friction, non-magnetic, no lubrication required.

Therefore, silicon nitride ceramic ball manufacturers are usually also the core supply chain partners of precision bearing manufacturers, widely serving in the automotive, motor, machinery manufacturing and new energy fields.

Silicon Nitride Ceramic Substrate (Si₃N₄ Substrate) is one of the core materials for the power electronics and semiconductor industry.
Due to its high thermal conductivity and low thermal expansion characteristics, it can effectively solve the problem of heat generation and thermal stress in power modules.

In particular, high thermal conductivity silicon nitride ceramic substrates and silicon nitride copper-coated ceramic substrates (Si₃N₄ DBC) are becoming important packaging substrates for IGBTs, MOSFET modules, and inverters for new energy vehicles.

Silicon nitride ceramics for semiconductors are also used in 5G communications, photovoltaic inverters, and aerospace electronics packages, providing reliable support for power density enhancement and system heat dissipation.

Silicon Nitride ceramic heating pads are able to heat up quickly and maintain a stable temperature in extreme environments due to their high thermal conductivity and electrical insulation properties.
It is often used:

• Semiconductor equipment thermostat system

• Aviation de-icing and anti-fogging devices

• Industrial heating equipment
  Its safety and energy efficiency are superior to traditional metal heating elements.

In the field of refractories, silicon carbide-bonded silicon nitride products and silicon carbide-bonded silicon carbide bricks have very high thermal shock and slag erosion resistance, and are commonly used in ladles, sintering furnaces and aluminum electrolysis tanks. The bonding phase of silicon nitride improves the oxidation resistance of the products, extends the life of the furnace lining and reduces maintenance costs.

The price of silicon nitride ceramics can vary depending on the density, machining accuracy, sintering process and application area.
Currently on the market:

• Structural component grade silicon nitride ceramics: approximately $300-800 per kilogram;

• High-precision silicon nitride ceramic balls: ranging from $2-10 each;

• High thermal conductivity substrate: $50-200 per piece.

With the maturity of domestic powder and equipment, a number of domestic silicon nitride ceramic ball companies and substrate manufacturers have achieved mass production.
Especially in Shenzhen, Wuxi, Dongguan and other regions, enterprises are through automated production lines to achieve high-performance silicon nitride ceramics scale manufacturing.

As a specialized manufacturer of advanced ceramics, we have the following advantages:

1. More than ten years experience in precision ceramics production
   We are deeply engaged in the research and development and custom processing of high-performance ceramics such as silicon nitride, aluminum nitride, alumina, and boron nitride.

2. Full Process Control System
   From powder preparation, molding, sintering to CNC precision machining and testing, the whole process is independently controlled to ensure product consistency and reliability.

3. High-precision equipment and testing
   With imported CNC grinding, laser interference detection and density analyzer, the dimensional accuracy can reach ±0.001mm.

4. Customization and Rapid Delivery Capabilities
   It supports small-lot trial production and rapid sample delivery to meet the diversified needs of research institutes and high-end manufacturing enterprises.

5. International Quality Certification
   Our products have passed ISO 9001, REACH and RoHS certifications and meet the standards of mainstream markets in Europe, America and Asia.

The future development of silicon nitride ceramics will focus on the following directions:

1. Higher thermal conductivity material systems (>100 W/m-K) for heat dissipation in high power electronics;

2. Si₃N₄-SiC composite ceramic structure to enhance flexural strength and crack resistance;

3. Microwave and flash sintering process to shorten the sintering cycle and reduce energy consumption;

4. 3D printed silicon nitride ceramic molding for rapid manufacturing of complex structural parts;

5. Ultra-precision silicon nitride ceramic processing technology for semiconductor devices and optical platforms.

These innovations will drive the continued expansion of the application boundaries of silicon nitride ceramics in new energy, aerospace, semiconductor manufacturing and precision engineering.

Silicon nitride ceramics are advanced inorganic non-metallic materials with both structural strength and functional properties.
It has low density, high strength, excellent thermal conductivity, good insulation, high temperature resistance, corrosion resistance, and is an important material for today's manufacturing upgrades and high-end equipment.

From silicon nitride ceramic balls to high thermal conductivity silicon nitride ceramic substrates to silicon nitride ceramic heating pads and silicon carbide combined with silicon nitride products.
This material has penetrated into various industries and become a key force in promoting China's advanced manufacturing and material localization.

In the future, with the sintering technology, powder purity and precision processing level, high-performance silicon nitride ceramics will become one of the core materials in the field of high-end equipment manufacturing and semiconductor packaging.