Silicon Carbide Tubes: Ideal for High-Temp, High-Pressure Heat Exchangers

In modern chemical and energy fields, the performance and durability of heat exchangers are directly related to production efficiency and cost effectiveness. ATCERA, a leading brand in the advanced ceramics industry, has introduced its innovative silicon carbide tubes for shell and tube heat exchangers, which greatly enhance the corrosion resistance and heat transfer performance of the equipment, providing the ideal solution for the treatment of various corrosive media. In this paper, the core characteristics and significant advantages of ATCERA silicon carbide tube and the application field of silicon carbide tube and shell heat exchanger will be discussed in depth.

 

 

Core Characteristics of Silicon Carbide Tubes for Shell and Tube Heat Exchangers

Silicon carbide tubes (SiC tubes) for shell and tube heat exchangers have a set of core characteristics that make them ideal for high temperature, high pressure and corrosive environments. The following is a detailed summary of the core characteristics of silicon carbide tubes:

High Strength & Hardness of Silicon Carbide Tubes

The hardness of silicon carbide tubes is very high, usually between 9-9.5 Mohs hardness, which is close to the hardness of diamond. This high hardness characteristic enables the silicon carbide tube to withstand extremely high mechanical stress and is not prone to deformation or rupture. At the same time, its high strength characteristics also ensure the stable operation of the shell and tube heat exchanger under high pressure working environment.

Excellent Wear Resistance of SiC Tubes

Due to the extremely high hardness of the silicon carbide tube, its wear resistance is also very good. In shell and tube heat exchangers, silicon carbide tubes can withstand fluid erosion and particle wear for long periods of time without significantly reducing their service life.

High Temperature Resistance of Silicon Carbide Tubes

Silicon carbide tube has excellent high temperature resistance and can be used stably in high temperature environment for a long time. Its use temperature can generally reach more than 1600 ° C, and even some special types of silicon carbide tubes can withstand extreme working environments of up to 2400 ° C or more. This makes silicon carbide tubes an ideal material for high temperature heat exchangers.

Corrosion Resistance Properties of SiC Tubes

Silicon carbide tube has good corrosion resistance, can withstand a variety of acid, alkali, salt and other chemical media erosion. In corrosive environments such as strong acids and alkalis, the surface of silicon carbide tubes usually forms a dense oxide film to protect them. This characteristic makes the silicon carbide tube perform well in the process of handling corrosive media.

Antioxidant Performance & Thermal Conductivity of SiC Tubes

When the silicon carbide material is heated to a certain temperature in the air, its surface will begin to form a protective layer of silicon dioxide. With the thickening of the protective layer, the continuous oxidation of the internal silicon carbide is prevented, so that the silicon carbide has better oxidation resistance. This characteristic helps to extend the service life of the silicon carbide tube and keep its performance stable.

Silicon carbide tubes have a high thermal conductivity, generally between 120-150 W/(m·K). This allows the silicon carbide tube to conduct heat quickly and is suitable for heat transfer applications in high temperature environments. In shell and tube heat exchangers, this characteristic of silicon carbide tubes helps to improve heat exchange efficiency and reduce energy consumption.

The thermal expansion coefficient of silicon carbide tube is low, generally between 4.0-5.0×10^(-6)/K. This allows the silicon carbide tube to maintain good dimensional stability under high temperature conditions, and is not easy to crack or deformation due to thermal expansion. This feature helps ensure long-term stable operation of the shell-and-tube heat exchanger.

Dimensional Stability & Customization Options of SiC Tubes

Silicon carbide tube can be processed and customized according to actual needs, including length, diameter, wall thickness and other parameters adjustment. This allows the silicon carbide tube to flexibly adapt to the design requirements of various shell and tube heat exchangers and meet the needs of use under different working conditions.

 

Advantages of ATCERA Silicon Carbide Tubes for Heat Exchangers

1. Comprehensive corrosion resistance: Whether it is acidic, alkaline or oxidizing media, ATCERA silicon carbide tubes can perform well and even handle extremely corrosive media.

2. Low maintenance and cost of ownership: High reliability and durability reduce maintenance requirements and reduce overall operating costs.

3. Extremely pure silicon carbide material: to ensure the purity of the medium, suitable for processes that are extremely sensitive to impurities.

4. Fast delivery and long life: short cycle production and long service life, creating greater value for users.

 

Application Areas of Silicon Carbide Shell Heat Exchangers

1. Condensation of ultra-corrosive and oxidizing vapors in multi-purpose units: silicon carbide tube and shell heat exchangers can effectively handle these difficult media to ensure the continuity and stability of the process.

2. Cooling or heating of ultra-corrosive and oxidizing liquids: Whether cooling or heating, the equipment can provide efficient and stable performance to meet the needs of complex processes.

3. Suitable for multi-purpose and single-purpose units: with its flexible design and wide adaptability, it is widely used in various chemical, pharmaceutical, energy and other fields.

 

In summary, ATCERA silicon carbide tubes are the preferred solution for handling corrosive media due to their excellent corrosion resistance, high heat transfer efficiency, high safety and reliability, as well as a wide range of applicability and customized design. Whether from the perspective of technological innovation, cost control or environmental protection, ATCERA provides users with a rare quality choice to help companies achieve more efficient and environmentally friendly production goals.

In the field of electronics industry, alumina substrate has become an indispensable base material for electronic components because of its excellent insulation, chemical stability, high thermal conductivity and good high-frequency performance. It not only plays the role of support and heat dissipation, but also ensures the insulation performance of electronic components. Alumina casting slurry is the key raw material for the preparation of alumina ceramic substrate, and its composition and characteristics directly determine the quality and performance of the final product. The purpose of this article is to investigate how the characteristics of alumina powder, including purity, size and specific surface area, morphology and dispersion, affect the casting process and the performance of alumina ceramic substrate.

 

 

Purity effect

The purity of alumina powder is the basis of casting slurry quality. The required alumina content is usually not less than 95% to avoid the negative impact of impurities on the appearance, shrinkage, microstructure and performance of the finished product. For example, aluminum oxide powders containing free Fe particles will lead to color development inside or on the surface of the ceramic during the sintering process, forming spots that not only affect the appearance, but also reduce the insulation performance.

 

The effect of powder size and specific surface area

The size of the alumina powder is controlled in the range of 0.3-1.7μm, and the specific surface area is between 2-11m²/g, which has an important impact on the density of the finished product. Small particle size powder has higher surface area and surface energy, which is conducive to the densification of casting film. However, too small particle size will increase the need for additives such as dispersants and binders, deteriorate slurry fluidity, increase sintering shrinkage, and reduce sintering density.

 

Effect of powder morphology

The morphology of alumina powder is various, including spherical, flake, fibrous and irregular. Because of its smooth surface and good fluidity, the spherical particles are conducive to improving the density of the finished product. In contrast, non-spherical particles are easy to form gaps after sintering, which affects the densification process.

 

Optimization of decentralization

Improving the dispersion of the powder in the slurry is the key to ensure the quality of the finished product. In addition to the addition of dispersants, the powder surface modification treatment, such as chemical modification or physical treatment, can significantly improve the dispersion and rheological properties of the slurry, so as to optimize the casting process.

 

In summary, the characteristics of alumina powder play a crucial role in the casting process of alumina ceramic substrate preparation. By strictly controlling the purity, size, surface area and morphology of the powder and optimizing the dispersion, the key performance indicators such as thermal conductivity, resistivity, dielectric constant, chemical stability and mechanical strength of the alumina ceramic substrate can be significantly improved. In the future, with the continuous progress of material science and preparation technology, the in-depth study and fine regulation of the characteristics of alumina powder will further promote the application and development of alumina ceramic substrates in the field of high-end electronic components, and provide a solid foundation for the sustainable development of the electronics industry.

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.

In the manufacturing process of SiC (silicon carbide) substrate, the cutting of SiC ingot is a crucial step. It not only directly determines the surface quality and dimensional accuracy of the substrate, but also has a decisive influence on cost control. The key parameters determined by the cutting process, such as surface roughness (Ra), total thickness deviation (TTV), warping (BOW) and bending (WARP), have a profound impact on the final quality, yield and production cost of the substrate. In addition, the quality of cutting is also directly related to the efficiency and cost of subsequent grinding and polishing processes. Therefore, the development and progress of SiC ingot cutting technology is of great significance to improve the level of the entire silicon carbide substrate manufacturing industry.

 

 

Diamond saw blade, circular saw blade, elimination, large Ra difference, large warpage, wide slit, slow speed, low precision, loud noise

Electric spark: wire + current, eliminated, wide slit, large surface burn layer thickness

Mortar line: copper-plated stainless steel wire + mortar, thin wafer, high yield, low loss, slow speed and low precision, pollution, low life of wire saw

Diamond wire: consolidated abrasive + diamond wire, high efficiency, narrow slit, environmental protection, deep damage layer, fast line wear, substrate warping

 

First, the status quo of SiC ingot cutting technology

With the advancement of science and technology, SiC ingot cutting technology has made remarkable progress. At present, the mainstream cutting technology mainly includes mortar wire cutting, diamond wire cutting and laser stripping technology. These technologies differ in cutting efficiency, surface quality, cost, etc., providing a variety of options for SiC substrate manufacturing.

 

Second, the main cutting technology characteristics analysis

1. Mortar wire cutting: As a traditional cutting technology, mortar wire cutting cuts SiC ingot through the line containing abrasive and mortar. Although this method is low cost and easy to apply in mass production, it is slow to cut and may leave a deep damaged layer on the substrate surface, affecting subsequent processing efficiency and substrate quality.

 

 

2. Diamond wire cutting: Diamond wire cutting technology uses diamond particles as abrasives to cut SiC ingot through high-speed rotating lines. This method not only has fast cutting speed, but also shallow surface damage layer, which helps to improve the quality and yield of substrate. Therefore, diamond wire cutting technology is gradually widely used in the field of SiC substrate manufacturing.

 

 

3. Laser stripping technology: Laser stripping technology is an emerging cutting method, which uses the thermal effect of the laser beam to separate the SiC ingot. This technology can provide very precise cuts, significantly reducing substrate damage, and thus improving the quality of the substrate. However, due to the relatively high cost at present, laser stripping technology is mainly used in high-end fields.

 

Third, the impact of cutting technology on substrate quality and subsequent processes

The choice of cutting technology not only affects the direct quality of SiC substrate, but also has an important impact on its subsequent processing. High-quality cutting technology can reduce substrate surface damage, reduce the difficulty and cost of grinding and polishing, thereby improving the efficiency and effectiveness of the entire production process. Therefore, in the manufacturing process of SiC substrate, it is very important to choose the right cutting technology.

 

In summary, the development and progress of SiC ingot cutting technology is of great significance for improving the quality, efficiency and cost control of SiC substrate. With the continuous progress of science and technology and the intensification of market competition, the future SiC ingot cutting technology will develop in the direction of more efficient, more accurate and more economical. At the same time, with the rapid development of new energy, semiconductor and other fields, the market demand for SiC substrate will continue to grow, providing a broad space and opportunities for the development of SiC ingot cutting technology.

With the rapid development of semiconductor technology, silicon carbide (SiC), as a semiconductor material with excellent physical and chemical properties, has shown great application potential in the field of high-performance electronic devices. However, to give full play to the advantages of SiC materials, the preparation of high-quality silicon carbide substrate is a crucial part. This paper aims to discuss the fine preparation process of SiC substrate, through a series of precise process steps to ensure that the final SiC substrate can meet the strict requirements of high-performance electronic devices.

 

 

1. Initial treatment: smooth and round

The SiC crystals obtained after the single crystal growth process must first be smoothed to eliminate surface unevenness and growth defects. This step provides a good basis for subsequent processing.

Then a rolling process is carried out to smooth the edge of the crystal anchor, creating favorable conditions for the cutting operation and reducing the risk of breakage during the cutting process.

 

2. Cutting and thinning

Using precision cutting technology, the SiC crystals are divided into multiple sheets, which will become the raw material for the SiC substrate.

The cut sheet is then ground to be thinned to the desired specification while ensuring the thickness uniformity of the substrate.

 

3. Surface quality improvement: mechanical polishing and chemical mechanical polishing

Mechanical polishing technology is used to further improve the smoothness of the substrate surface and remove the damaged layer that may occur during grinding.

The chemical mechanical polishing (CMP) process further improves the flatness and cleanliness of the substrate surface, and achieves higher surface quality through the synergistic effect of chemistry and machinery.

 

4. Cleaning and testing

The polished SiC substrate needs to be thoroughly cleaned to remove the residual polishing liquid and particles on the surface to ensure the cleanliness of the substrate.

Finally, the SiC substrate is tested comprehensively, including surface quality, thickness uniformity, defect density and other key indicators, to ensure that the substrate meets the manufacturing requirements of high-performance electronic devices.

 

Through the above series of precise process steps, the fine preparation process of SiC substrate can be completed. From the initial grinding and rounding, to the cutting and thinning, to the improvement of the surface quality and the final cleaning and inspection, each step is crucial and together form the complete chain of high-quality SiC substrate preparation. The strict execution and continuous optimization of these process steps provide a solid foundation for the manufacture of high-performance semiconductor devices, and promote the wide application and development of SiC materials in the field of high-performance electronic devices. In the future, with the continuous progress and innovation of technology, the preparation process of SiC substrate will be more perfect, and new vitality will be injected into the sustainable development of semiconductor industry.

With the wide application of silicon carbide (SiC) in semiconductor devices, the quality requirements of silicon carbide substrates are becoming more and more stringent. SiC devices have strict regulations on the surface thickness change, surface roughness (Ra), machining damage and residual stress of the liner film. However, the SiC substrate after cutting and stripping often has problems such as damaged layer, high surface roughness and poor flatness. These problems must be solved by effective flattening process to obtain high quality polished sheet for subsequent epitaxy process. This article will focus on the grinding and grinding technology in the SiC substrate flattening process, and compare and analyze their advantages and disadvantages.

 

 

1. Current situation and limitation of grinding process

 

The grinding process has a high share of the market, including two stages of rough grinding and fine grinding, and requires single-side mechanical polishing (DMP) before chemical mechanical polishing (CMP). Its advantage is that the cost is relatively low, but there are disadvantages such as cumbersome processes, low automation level, high fragmentation risk, low flexibility and certain impact on the environment.

 

 

2. Advantages and adaptability of grinding process

 

The grinding process, as an alternative to the grinding process, provides higher material removal rates and better control of wafer thickness and flatness. It uses different abrasives and grinding techniques, such as diamond grinding wheels, to achieve a finer and more uniform surface treatment. The grinding process is excellent in terms of automation and flexibility, suitable for single chip processing, and can better adapt to the processing needs of large-size wafers.

 

 SiC substrate flattening process diagram

 

The grinding process usually includes two stages of coarse grinding and fine grinding, and the damaged layer of the substrate surface is gradually removed by different particle sizes of the abrasive material to improve the surface smoothness. However, the process has many problems. First of all, the process is more complicated, from rough grinding to fine grinding to DMP and CMP, requires multiple steps, increasing the processing time and cost. Secondly, the level of automation is not high, resulting in low production efficiency. For large wafers, there is a high risk of fragmentation due to mechanical stress during processing. In addition, the flexibility of the grinding process is low, which is not conducive to single chip processing, and the use of grinding fluid has a certain impact on the environment.

 

The grinding process uses highly efficient abrasives such as diamond wheels to achieve rapid flattening of SiC substrates with higher material removal rates. Compared with grinding process, grinding process has the following advantages: first, high degree of automation, can significantly improve production efficiency; The second is good flexibility, suitable for single piece processing, can be customized according to different needs; Third, it can better adapt to the processing needs of large-size wafers and reduce the risk of fragmentation. In addition, the grinding process enables a finer and more uniform surface finish, providing a better substrate for subsequent CMP processes.

 

In summary, the grinding and grinding techniques in the SiC substrate flattening process have their advantages and disadvantages. Although the grinding process cost is low, but the process is cumbersome, the level of automation is not high, the risk of fragmentation is high and the flexibility is low, which limits its further development. In contrast, the grinding process shows obvious advantages in terms of automation, flexibility, material removal rate and surface treatment quality, which is more suitable for the high-quality requirements of SiC substrates in the modern semiconductor industry. Therefore, with the continuous progress of semiconductor technology, grinding process is expected to become the mainstream technology of SiC substrate flattening. In the future, grinding process parameters should be further optimized to improve processing efficiency and quality to meet the increasingly stringent substrate requirements of SiC devices.

With the continuous progress of semiconductor technology, silicon carbide (SiC), as a high-performance material, has shown great application potential in the field of power electronic devices. However, in the preparation process of silicon carbide substrate, surface quality control is particularly critical, especially after thinning, grinding and polishing and other processes to obtain ultra-smooth surface. Among them, chemical mechanical polishing (CMP), as one of the key steps, is of great significance for removing the damaged layer left by the previous process and achieving high surface levelling. However, the traditional CMP process faces the problem of low material removal rate (MRR), which directly affects the production efficiency and cost. Therefore, exploring new technologies to improve the CMP efficiency of SiC substrate has become the focus of current research.

 

 

1. Basic principles and challenges of SiC substrate CMP

The surface damage depth of the thinned or ground SiC substrate is usually 2-5μm and requires further treatment by CMP.

CMP technology is based on the "chemical + mechanical" composite principle, through the combination of oxide layer formation and mechanical removal, to achieve surface smoothing.

 

2. Low MRR is the main problem of SiC substrate CMP, and the CMP efficiency of SiC is significantly lower than that of silicon substrate.

The impact of low MRR on production efficiency and cost:

Lower MRR results in longer time consuming SiC substrate CMP steps, increasing processing time and cost.

Even if the existing CMP method can produce qualified 4H-SiC substrate, low efficiency is still the bottleneck restricting its large-scale application.

 

CMP polishing process

 

3. Technical progress to improve CMP efficiency:

To meet the low MRR challenge, the industry has developed double-sided, batch polishing technology.

These advanced technologies have significantly reduced CMP man-hours, such as the CMP polishing time for a single batch of 10 substrates from 3-5 hours to 1 hour.

Double-sided polishing technology not only improves efficiency, but also helps maintain consistency and flatness on both sides of the substrate.

 

 

In summary, the improvement of chemical-mechanical polishing efficiency of silicon carbide substrate is the key to promote its wide application. Through the development of advanced technologies such as double-sided and batch polishing, the problem of low material removal rate in the traditional CMP process is effectively solved, the processing time is significantly shortened, and the production cost is reduced. In the future, with the continuous improvement of the performance requirements for SiC materials and the continuous innovation of polishing technology, we have reason to believe that the preparation of SiC substrates will be more efficient and economical, laying a solid foundation for the further development of power electronic devices. Therefore, the continuous exploration and optimization of CMP process will be an important way to promote the wide application of SiC materials in the semiconductor field.

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.

Silicon carbide substrate, as a new generation of semiconductor products, has shown great application potential in the field of power electronic devices because of its excellent physical and chemical properties. However, high efficiency and low loss cutting of SiC ingot is one of the key technologies restricting its mass production. At present, mortar wire cutting and diamond wire cutting are the two mainstream technologies in SiC ingot cutting, and they have significant differences in the ways of abrasive introduction, processing efficiency, material loss and environmental impact. This article aims to compare and analyze the characteristics of these two cutting technologies, and discuss the optimization direction of SiC cutting process.

 

 

1. Abrasive import mode and processing efficiency

· mortar wire cutting: using free abrasive, the processing speed is relatively slow.

· diamond wire cutting: through electroplating, resin bonding and other methods to fix the abrasive particles, cutting speed increased by more than 5 times, significantly improve production efficiency.

2. Material loss and film output rate

· mortar wire cutting: low output rate, large material loss.

· diamond wire cutting: the output rate is increased by 15% to 20%, the material loss is significantly reduced, and the economic benefit is improved.

3. Environmental protection advantages

· Diamond wire cutting: Less waste and wastewater production, more environmentally friendly.

4. Technical challenges and coping strategies

· Diamond wire cutting: There are challenges in crystal control and cutting loss control.

· Coping strategy: The current industry adopts the strategy of mortar wire cutting as the main and diamond wire cutting as the auxiliary, the use ratio is about 5:1. In the future, it is necessary to further optimize the diamond wire cutting technology to improve its competitiveness in SiC cutting.

5. Processing loss analysis of SiC materials

· mortar wire cutting loss:

· Notch loss: up to 150-200 microns.

· Polishing loss: Surface damage needs to be repaired by rough grinding, fine grinding and CMP processes.

· back thinning loss: The initial thickness setting is high, the back thinning is required to reduce resistance.

 

 SiC cutting loss and damage

 

In summary, the diamond wire cutting technology in the cutting of SiC ingot shows significant processing speed advantages, lower material loss and environmental protection advantages, but its crystal control and cutting loss control still need to be further optimized. At present, the complementary use strategy of mortar wire cutting and diamond wire cutting is a common practice in the industry. In the future, with the continuous progress of diamond wire cutting technology and the reduction of costs, it is expected to occupy a dominant position in the SiC cutting field. At the same time, in view of the loss problem in the processing of SiC materials, it is necessary to further explore more efficient and low-loss cutting and polishing processes to promote the efficient and low-cost production of SiC semiconductor materials and promote its wide application in the field of power electronic devices.

In the rapidly developing electronics industry, alumina substrate has become an indispensable substrate for electronic components with its excellent insulation properties, chemical stability, high thermal conductivity and good high-frequency characteristics. It not only provides support for electronic components, but also plays a key role in heat dissipation and insulation. However, the preparation process of high quality alumina ceramic substrate is complex and fine. The key factors such as raw material formula, casting film thickness and sintering process parameters directly affect the thickness uniformity, appearance quality and surface roughness of the product, and then determine the overall performance of the product. In this article, the effects of three key additives, binder, plasticizer and dispersant, and their process control were discussed in order to provide reference for optimizing the preparation process of alumina ceramic substrate.

 

 

Selection of binder and control of additive amount

As a key organic additive for the construction of three-dimensional networks of ceramic sheets, binders must be soluble in selected solvents, and common types include polyethylene, polyvinyl alcohol, etc. The effect of the appearance, processing characteristics and porosity of the casting green billet on the performance of the product should be considered comprehensively when the amount of binder added. The proper amount of binder can ensure the strength and toughness of green billet, but too much binder will lead to the difficulty of degreasing and the decrease of green billet density, which will affect the shrinkage rate and mechanical properties of finished product. Too little can not effectively bond the powder.

 

Introduction and balance of plasticizers

By reducing the plastic limit temperature of the binder, the plasticizer enhances the flexibility and workability of the cast film, solves the problem of insufficient toughness after drying, and improves the stability of the slurry. However, the addition of plasticizers should be moderate to avoid excessive reduction of film strength. The ideal plasticizer should have stable physicochemical properties that are compatible with other ingredients of the paste, ensuring minimal addition while maintaining performance.

 

Common binders correspond to plasticizers

 

Selection and dose adjustment of dispersant

The good dispersion of powder in slurry is the basis of preparing high quality alumina ceramic substrate. The dispersing agent promotes the suspension of particles through electrostatic and steric hindrance and stably disperses. Depending on the slurry system, it is important to choose the right type of dispersant (such as inorganic, organic, polymer and composite dispersant). The amount of dispersant added is adjusted according to the size of the alumina powder, and fine particles usually need more dispersant because of their high surface energy.

 

In summary, the selection and process control of binder, plasticizer and dispersant have a decisive influence on the performance of the final product during the preparation of alumina ceramic substrate. The thickness uniformity, appearance quality and surface roughness of alumina ceramic substrate can be effectively improved by precisely regulating the types and amounts of these additives, combined with the optimized casting film thickness and desviscose sintering process parameters, so as to ensure its excellent performance in electronic components. In the future, with the continuous progress of material science and preparation technology, further optimization of additive formulation and process parameters will open up new possibilities for the application of alumina ceramic substrates in a wider range of fields.