As a high-performance material, alumina substrate has been widely used in electronics, aerospace and new energy fields. The preparation process involves many complicated processes, in which casting and drying process are the key links to ensure the quality of the substrate. In this article, the effects of raw material formula, casting film thickness and sintering process parameters on the properties of alumina ceramic substrate were investigated, and the drying process after casting and its mechanism on the quality of the substrate were analyzed.

 

 

Raw material formula and casting film thickness control:

The final thickness and thickness uniformity of alumina ceramic substrate are directly affected by the precise ratio of raw material formulation and the appropriate thickness of cast film strip. A reasonable ratio of raw materials helps to form a stable casting slurry, and the choice of film thickness determines the initial shape of the green strip, which jointly determines the basic quality of the substrate.

 

Influence of sintering process parameters:

Debonding sintering is a key step in substrate preparation, and its process parameters such as temperature and time directly affect the appearance quality and surface roughness of the substrate. Optimizing these parameters can significantly improve the overall performance of the substrate, such as increasing strength and reducing porosity.

 

Importance of drying process and phased implementation:

Due to the high viscosity properties of the cast slurry, the drying process is the key to ensure the strength and complete stripping of the green strip. During the drying process, the production and release of the internal stress of the green sheet and the imbalance of the specific gravity caused by the volatilization of the solvent require the formulation of an accurate drying process. The constant speed drying stage aims to quickly evaporate the liquid phase film on the surface, while the reduced speed drying stage focuses on the slow diffusion of the internal solvent to ensure drying uniformity and avoid defects such as cracking and warping.

 

Specific analysis of drying process:

In the drying process of green strip, because the evaporation rate of liquid film on the surface is much higher than the diffusion rate of solvent inside, it needs to be carried out in stages. In the constant drying stage, the drying rate is constant, which matches the evaporation rate of the surface solvent, and the surface liquid phase film is mainly removed. When the surface drying is completed, it enters the reduced speed drying stage, and the drying rate is gradually reduced to adapt to the rate of internal solvent diffusion to the surface, ensuring the uniformity and stability of the drying process.

 

In summary, the preparation process of alumina ceramic substrate requires strict control of raw material formula, cast film thickness and desviscosification sintering process parameters. As a key step, the accurate implementation of drying process is crucial to ensure the thickness uniformity, appearance quality and surface roughness of the substrate and other engineering application indicators. By implementing constant speed and reduced speed drying in different stages, the stress change inside the green sheet can be effectively controlled, and the drying defects can be avoided, which provides a strong guarantee for the preparation of high-performance alumina ceramic substrate. In the future, with the continuous progress of material science and preparation technology, the preparation process of alumina ceramic substrate will be more refined and intelligent, providing a more high-quality material basis for applications in various fields.

Because of its excellent mechanical properties, thermal stability and chemical inertness, alumina substrate has shown wide application potential in electronic packaging, thermal management and high-performance structural parts. The preparation process involves complex process steps, in which casting process, as the core link, plays a decisive role in the performance of the final product. This paper aims to discuss the key control points in casting process, such as raw material formula, casting film strip thickness and sintering process parameters, analyze how these parameters affect the thickness uniformity, appearance quality and surface roughness of alumina ceramic substrate engineering application indicators, so as to optimize the preparation process and improve the overall performance of the product.

 

 

Raw material formulation and slurry characteristics

The raw material formula is the basis of alumina ceramic substrate preparation, which directly affects the viscosity, solid content and other key physical properties of the slurry. Suitable slurry formulation helps to achieve good casting effect and uniform film distribution. The viscosity of the slurry should be moderate, which can ensure good spreading and avoid cracks or deformation during the drying process.

 

 

Casting film thickness control

The thickness of the cast film strip is a key factor in determining the final thickness tolerance of the substrate. In addition to the slurry state, the height of the casting blade also directly affects the thickness of the dry film. The thickness distribution of the film can be optimized by precisely controlling the height of the blade and the velocity of the film (uniform linear motion), and the phenomenon of thick center and thin sides can be reduced. For the substrate requiring high precision, the casting machine with adjustable blade surface curve becomes a necessary choice.

 

 

Desticking sintering process parameters

Debonding sintering is a key step in the preparation of alumina ceramic substrate, which directly affects the density, strength and microstructure of the substrate. Reasonable sintering temperature and holding time are helpful to eliminate the internal pores and improve the mechanical properties and thermal stability of the substrate. At the same time, the atmosphere control in the process of debonding is also an important factor affecting the quality and performance of the substrate.

 

Casting process flow chart

 

In summary, the preparation process of alumina ceramic substrate is a complex system engineering involving multi-factors and multi-steps. The rational selection and optimization of key control points such as raw material formula, casting film thickness and sintering process parameters are very important to improve the thickness uniformity, appearance quality and surface roughness of the substrate. Through in-depth study of the mechanism of influence of these parameters, combined with advanced preparation technology and equipment, the overall performance of alumina ceramic substrates can be further improved to meet the stringent requirements in high-performance electronic packaging, thermal management and structural components. In the future, with the continuous progress of material science and preparation technology, the preparation process of alumina ceramic substrate will be more refined and intelligent, providing a more solid foundation for the development of related fields.