It is well known that the heat generated by the semiconductor devices work is the key factor that causes for the failure of semiconductor devices, and the thermal conductivity of the insulating substrate is the key to affect the whole semiconductor cooling device, in addition, due to the often face the complex mechanics environment such as turbulence, vibration, substrate material also need certain mechanical reliability, silicon nitride ceramic various aspects performance is balanced, It is a structural ceramic material with the best comprehensive performance, so it has a strong competitiveness in the field of ceramic substrate manufacturing of power electronic devices.So what are the specific advantages of silicon nitride ceramic substrate?
Anyone with a basic knowledge of chemistry knows that nitrogen and silicon are abundant on Earth, and that the material made up of these two elements is silicon Nitride (Si3N4). The modern functional ceramics made of silicon nitride as the main material have a wide range of applications.
In the past, the circuit base board is a combination of separated components or integrated circuit and discrete component circuit, forming a flat material to meet the functional requirements of the overall circuit, and the requirements are only insulation and conduction. Intelligent and enter the information age, the power electronic device also can carry on the transformation to the power and control, thus greatly enhance the components of electronic control and power conversion performance requirements and operating power consumption, accordingly, common substrate complex power devices have been unable to meet the lower thermal resistance, high operating temperature control, guarantee the reliability of the request, must be replaced performance better, A new type of power ceramic substrate emerged.
Based on the performance requirements of the ceramic substrate for electronic devices, the substrate material shall have the following properties:
Good insulation and electrical breakdown resistance;
High thermal conductivity: thermal conductivity directly affects the operating condition and service life of the semiconductor, and the uneven distribution of temperature field caused by poor heat dissipation will also greatly increase the noise of electronic devices;
Thermal expansion coefficient is matched with other materials used in the package;
Good high frequency characteristics: low dielectric constant and low dielectric loss;
Smooth surface, uniform thickness: easy to print the circuit on the substrate surface, and ensure that the thickness of the printed circuit is uniform.
Compared with other ceramic materials, silicon Nitride ceramic materials have obvious advantages, especially under high temperature conditions, silicon nitride ceramic materials show high temperature resistance, chemical inertia to metal, super high hardness and fracture toughness and other mechanical properties.
Since silicon nitride is so excellent, why the market application is still less, where is its development opportunity?
In fact, the three materials have their own advantages and disadvantages, such as alumina, although the thermal conductivity is poor, can not keep up with the development trend of high-power semiconductors, but its manufacturing process is mature, low cost, in the low-end area still has a great demand. Aluminum nitride thermal conductivity is the best, and semiconductor materials have a good match, can be used in high-end industries, but the mechanical properties are poor, affect the life of semiconductor devices, the use of high cost.
Silicon nitride has the best performance in terms of comprehensive performance, but the threshold for entry is very high. At present, many domestic scientific research units and enterprises are studying it, but the technical difficulty is high, the processing cost is high, and the market is small, and there is no opportunity for large-scale application, which is also the reason why many enterprises are still waiting and not determined to increase investment.
However, the situation is different now, because we have entered the critical period of the development of the third generation semiconductor.
It has been introduced in the previous article of powder ring push that the third generation semiconductor is the development trend of 5G era, but they need to be used, but cannot do without the assistance of ceramic substrate, otherwise even if the performance is superior, its heat dissipation effect will be greatly reduced.
At present, in the third generation of semiconductor, such as gallium nitride, silicon carbide and other performance requirements of high power ceramic substrate materials, integrated down the most promising material is: silicon nitride ceramics. Its high thermal conductivity, high current load, relatively easy to meet the heat dissipation requirements of the third generation of power semiconductor devices, thermal expansion coefficient and most semiconductor materials match, electrical and mechanical properties also have a good level.
Relatively speaking, under the influence of the barrel effect, silicon nitride is more suitable for the future high performance era.
Because power integrated circuit ceramic substrate position for the development of power electronic technology, so it become the western developed countries for our domestic technology blockade, one of the key materials in all western countries are now limiting silicon nitride ceramic substrate production technology into our country, and silicon nitride ceramic substrate in the United States and Japan also have mature product, The complete set of technology for the third generation semiconductor devices has also been industrialized.
The development of The Times is pushing the whole industry forward, because silicon nitride is the third generation of high-power semiconductor devices supporting materials, not only will promote the development of the national economy, but also has strategic significance for China’s national defense construction, so it is not too much to say that silicon nitride ceramic substrate is a world-class strategic product.
And the key is the most important industry, silicon nitride ceramic substrates have to be supporting and the third generation of high power semiconductor devices, is a complex system engineering, not only need massive funds with more comprehensive technology integration, to have a strong organization to coordinate, to finish the task.