Spherical Alumina: The Ultimate Versatile Thermal Material for Diverse Applications
In this era of rapid technological advancement, thermal conductive materials play an indispensable role in many fields. Kastar's spherical alumina products provide high-quality thermal solutions for customers. Today, let us take a closer look at this highly regarded spherical alumina product.
Spherical alumina is a high thermal conductivity, high dielectric premium filler material made from irregular high-purity powder through high-temperature melting and rapid cooling to form spherical particles under surface tension, followed by refining processes including purification, classification and modification. It appears as white powder with a melting point of 2050°C, thermal conductivity of 30W/(m·K), and dielectric constant of approximately 8.2-9.0 at frequencies between 1kHz-100MHz.
PART 1 Advantage
Kastar's spherical alumina products feature high sphericity, high alpha-phase conversion rate, high chemical purity, high filling rate, high whiteness, low viscosity, narrow particle size distribution, and diverse product specifications. These products are widely used in new energy vehicles, consumer electronics, network communications, engineering plastics, functional fillers, special ceramics, additive manufacturing and other fields.
01 High Thermal Conductivity
The particles exhibit excellent surface morphology and narrow particle size distribution, enabling high-density filling in silicone, epoxy, and plastic systems to form high thermal conductivity composites. Ideal for applications requiring superior heat dissipation, such as in electronic device cooling, where it effectively reduces operating temperatures and extends product lifespan.
02 High α-Phase Conversion Rate
Proprietary technology ensures tightly packed α-Al₂O₃ crystal structure with strong ionic bonding between oxygen and aluminum atoms, facilitating rapid heat transfer. Maintains stable thermal performance in high-temperature environments, demonstrating exceptional performance in LED lighting heat dissipation applications.
03 High Sphericity Ratio
Through precision raw material selection and core technologies including advanced dispersion, precise spheroidization, and morphology control, the product achieves high sphericity with minimal surface defects, low particle agglomeration, and narrow size distribution. Enhances material flowability and uniformity in filling applications, such as in thermal potting compounds, ensuring optimal filling performance.
04 Low Filling Viscosity
Specialized spheroidization and chemical treatment processes yield particles with smooth surfaces and high chemical purity. Delivers excellent insulation properties, superior dispersibility, and low viscosity in organic systems, meeting demanding application requirements. Facilitates processing and molding in electronic packaging materials, thereby improving production efficiency.
PART 2 Introduction
01 SAF Series, SAT Series
Product Name: Sub-spherical Single Crystal α-Alumina
Product Features:
Produced via single crystal manufacturing process with sub-spherical morphology, delivering higher thermal conductivity per unit volume while maintaining excellent absolute filling capacity in various resin systems.
02 SAK Series
Product Name: Single Crystal Polyhedral α-Alumina
Product Features:
Manufactured using single crystal production technology with narrow particle size distribution. The unique polyhedral morphology creates optimal thermal conduction pathways between particles while maintaining excellent absolute filling capacity in various resin systems.
03 QD Series
Product Name: Spherical Thermal Conductive Alumina
Product Features:
Manufactured from high-density raw materials with high sphericity ratio. The water-washing process makes it cost-effective for applications with stringent viscosity requirements.
04 HA Series
Product Name: Angular High Thermal Conductive Alumina
Product Features:
Cost-effective solution for resin systems requiring low filler loading or where flowability is not critical. Smaller particle sizes are also used in combination with spherical alumina products.
PART 3 Application
Thermal Interface Materials
In thermal interface materials such as thermal conductive silicone pads, thermal greases, and potting compounds, spherical alumina serves as a critical filler that significantly enhances thermal conductivity. Applied in smartphones, tablets, laptops, and other electronic devices, it effectively dissipates heat during operation, ensuring optimal component temperatures for improved performance and extended lifespan.
Thermal Conductive Engineering Plastics
When used in LED lamp covers, switch housings, electronic enclosures, and heat-dissipating components, spherical alumina endows engineering plastics with superior thermal management and mechanical properties. In LED lighting, it boosts heat dissipation efficiency to prolong service life; in electronic housings, it enhances thermal performance while maintaining structural integrity.
Chip Packaging
For high-performance or specialized chip packaging (e.g., memory, CPU, GPU), spherical alumina meets stringent requirements for low α-ray emission, high thermal conductivity, and electrical insulation. Its exceptional properties ensure stable operation and reliability in advanced semiconductor applications.
Thermal Conductive Aluminum-Based Copper Clad Laminates
As a filler in high-power LED circuit boards, power PCBs, and semiconductor packaging resins, spherical alumina improves both thermal conductivity and insulation. It guarantees stable performance for high-power electronic components, enhancing circuit board reliability and longevity.
Ceramic Applications
In ceramic materials, spherical alumina markedly improves toughness, hardness, and wear resistance. For ceramic cutting tools, it enhances cutting precision and durability; for artware, it elevates quality and aesthetics. As a polishing abrasive, it achieves scratch-free, high-gloss finishes—critical for precision optical components.
3D Printing
With high strength, sphericity, and heat resistance, spherical alumina is ideal for 3D printing. Its slurries offer high solid content, excellent flowability, easy cleaning, and robust mechanical properties. In aerospace, automotive, and medical device manufacturing, it enables complex geometries and high-performance parts, driving innovative design and R&D.