Thanks to their outstanding insulation properties, thermal stability, and low coefficient of thermal expansion, spherical silica fume has become a key filler material for electronic packaging, copper-clad laminates, and 5G high-frequency applications. The market size is projected to surpass 8 billion yuan by 2025.
 
Silica micro powder is produced through a multi-stage, meticulous processing of natural quartz or fused quartz, involving steps such as crushing, ball milling (or vibration milling, air-flow milling), flotation, acid leaching for purification, and high-purity water treatment—ultimately resulting in its fine powder form.
 
In terms of morphology, silicon micropowder can be categorized into angular and spherical types. Among these, spherical silicon micropowder is particularly widely used in the electronics industry—for applications such as packaging for large-scale integrated circuits, filler materials for copper-clad laminates in electronic and electrical components, as well as in coatings and the pharmaceutical sector. This type of spherical silicon micropowder appears as a white powder, characterized by uniform particle size, high sphericity, excellent flowability, superior insulation properties, and minimal magnetic impurities. Additionally, it boasts advantages like low dielectric constant, low dielectric loss, and a small linear thermal expansion coefficient, making it exceptionally effective across various application fields. Spherical silicon micropowder, with its unique shape and outstanding performance, plays a critical role in the electronics industry. Compared to angular silicon micropowder, the spherical variety offers significant benefits, including enhanced surface flowability, uniform resin dispersion for film formation, higher packing density, and superior thermal expansion and thermal conductivity characteristics. These attributes make spherical silicon micropowder an ideal choice for manufacturing electronic components, significantly improving both product performance and longevity.
 
I. Preparation of Silica Fume
 
Additionally, spherical silicon micropowders demonstrate unique advantages during the preparation process. Their preparation methods primarily include physical, chemical, and physicochemical approaches. Among these, physical techniques such as flame spheroidization and high-temperature melt spraying effectively control the degree of sphericity and particle size distribution of the silicon micropowder. Meanwhile, chemical methods like vapor-phase synthesis and hydrothermal synthesis allow precise manipulation of the powder's morphology and performance at the molecular level. These diverse preparation techniques enable spherical silicon micropowders to meet the specific requirements of various application fields.
 
In industrial production, the physical method dominates the preparation of spherical silicon micropowders. This is because the physical method offers advantages such as simple processes, high output, and low costs, making it well-suited for large-scale manufacturing needs. Meanwhile, with continuous advancements in technology, chemical and physicochemical methods are also steadily evolving and improving, providing more options and possibilities for producing spherical silicon micropowders. Among the physical methods, the flame-spheroidization technique is particularly favored due to its ease of scaling up for industrial production. The process involves several key steps: first, high-purity quartz sand undergoes meticulous pre-treatment, including crushing, sieving, and purification; next, the treated quartz micropowder is fed into a high-temperature environment for melting and subsequent cooling into spherical particles. Throughout this process, the stability of the heating equipment plays a crucial role, directly influencing the purity and sphericity of the final product. Key equipment components include powder metering and conveying systems, precise gas-flow control mechanisms, mixing units, high-temperature flame burners, and efficient cooling and recovery systems.
 
The high-temperature melt-jet method involves placing the material in a high-temperature environment to melt it into a molten state. At the precise moment the molten material flows out, it is sprayed with high-pressure air from an atomizer. This high-speed airflow breaks up and disperses the molten material into fine, mist-like droplets, which are then rapidly cooled. As the droplets cool, they naturally contract quickly, forming smooth, spherical particles. This method is particularly advantageous because it most easily ensures both sphericity and amorphousness of the final product. However, key technical challenges remain unresolved—such as developing advanced high-temperature materials for the furnace, effectively atomizing the viscous molten quartz, and preventing secondary contamination—making it extremely difficult to produce high-purity, spherical silicon micropowders using this process.
 
The plasma method involves melting and vaporizing silicon micropowder in the high-temperature field of a plasma torch, followed by rapid cooling to form spherical particles. This method boasts high energy input, efficient heat transfer, and swift cooling, resulting in products with controllable morphology, high purity, and minimal agglomeration.
 
Silica fume is produced by the high-temperature hydrolysis and polycondensation of chlorosilanes in a hydrogen-oxygen flame, forming silica particles. These particles are then rapidly cooled, causing them to agglomerate into larger clusters, followed by gas-solid separation and acid removal processes. The advantages include the high purity of the resulting spherical silicon micropowder, with particle sizes ranging from 15 nm to 35 nm and specific surface areas between 65 m²/g and 355 m²/g—plus a mass fraction exceeding 99.9%. However, a notable drawback is that these particles tend to disperse poorly in organic media, potentially leading to environmental contamination if not handled carefully.
 
The precipitation method uses water glass and an acidifying agent as raw materials. A surfactant is added at the right time, while the reaction temperature is carefully controlled. When the solution reaches a specific pH value, a stabilizer is introduced. The resulting precipitate is then washed, dried, and calcined to yield spherical nanoscale silicon micropowder. This method offers several advantages: the spherical silicon micropowder produced via precipitation has highly uniform particle size, low production costs, a straightforward and easily manageable process, making it well-suited for industrial-scale applications. However, one potential drawback is the risk of agglomeration occurring during the process.
 
The hydrothermal synthesis method typically involves high temperatures ranging from 150°C to 350°C, combined with elevated pressure, to facilitate the chemical reaction between inorganic and organic compounds with water. Through vigorous convection, ions, molecules, and ion clusters are transported into a growth zone containing seed crystals, ultimately leading to the formation of supersaturated solutions and subsequent crystallization. Following filtration, washing, and drying, this process yields ultrafine, high-purity microparticles. Notably, it eliminates the need for calcination—a common step in conventional liquid-phase synthesis used to convert materials into oxides—thereby significantly reducing the likelihood of hard agglomeration.
 
The sol-gel method is a process in which compounds containing highly reactive components are first dissolved in a solution, then transformed into a sol, and subsequently solidified into a gel. This gel-like material is further treated thermally to form oxides or other solid compounds. Typically, silicates such as TMOS and TEOS are used as the silicon source, with alcohols serving as the solvent. Under either acidic or basic conditions, the silicate undergoes hydrolysis and condensation reactions, initially forming a stable silica sol system. Over time, this sol ages and gradually evolves into a gel. Finally, after drying and sintering, the gel is fully固化 to yield spherical silica powder materials.
 
The microemulsion method uses two immiscible solvents, stabilized by a surfactant, to form a uniform emulsion. This confines processes such as nucleation, particle formation, coalescence, and aggregation within tiny spherical droplets, ultimately leading to the precipitation of a solid phase from the emulsion and the creation of spherical particles.
 
II. Applications of Silica Fume
 
1. Copper Clad Laminate Filling Applications
 
Spherical silica fume plays a critical role in the copper-clad laminate industry thanks to its outstanding electrical insulation properties, thermal stability, and resistance to acids, alkalis, and abrasion. Widely used as a functional filler, it effectively enhances the mechanical, thermal, and electrical performance of copper-clad laminates. Moreover, by applying special surface treatments or modifications, its compatibility with epoxy resins can be further improved, strengthening the bond between the two materials and boosting the overall rigidity and other key strength characteristics of the final product. In the 5G era, high-frequency, high-speed copper-clad laminates are increasingly favored. According to forecasts, the domestic market for silica fume used in copper-clad laminates is expected to reach 2.77 billion yuan, 3.2 billion yuan, and 3.5 billion yuan from 2023 to 2025, with the segment specifically tailored for high-frequency, high-speed applications projected to grow to 940 million yuan, 1.03 billion yuan, and 1.11 billion yuan during the same period.
 
2. Epoxy Molding Compound
 
Epoxy molding compounds are critical materials used for chip encapsulation. The type and dosage of fillers significantly influence the thermal performance of the molding compound. Among them, spherical silica powder effectively enhances flowability and allows for higher filler loading, which in turn helps reduce the coefficient of thermal expansion and minimizes wear on equipment and molds. It is commonly used as a key filler in epoxy molding compounds designed for high-end device packaging, making it the mainstream filler currently employed in such applications.
 
According to Yole data, the global advanced packaging market reached US$30.4 billion in 2020, accounting for 45% of the global packaging market. By 2026, advanced packaging is expected to capture 50% of the global market, becoming the primary driver of growth in the global semiconductor testing and packaging industry. The rapidly expanding demand for advanced packaging is also boosting growth opportunities for spherical silicon micropowders. By 2025, China's market for silicon micropowders used in epoxy molding compounds is projected to reach 4.52 billion yuan.
 
3. Cosmetic Ingredients
 
Spherical silica powder, processed through a unique technique, exhibits excellent particle size distribution and surface area. Its smaller average particle size delivers exceptional smoothness, while the narrower particle size distribution ensures superior flowability and a pleasant tactile feel. Additionally, its larger specific volume makes cosmetic formulations more cost-effective. More importantly, its high specific surface area endows it with outstanding absorption capabilities, enabling it to effectively capture fragrances, nutrients, and protective chemicals.
 
4. Advanced Ceramic Raw Materials
 
High-purity spherical silica fume plays a critical role in specialized high-temperature-resistant ceramic materials, effectively lowering firing temperatures and boosting product yield. Additionally, it is widely used as a carrier and filler to enhance the toughness and surface finish of ceramic products. Spherical silica fume combined with high-performance resins and ceramics makes an ideal material for heat-resistant tiles in aerospace vehicles. This material finds extensive applications in fields such as precision ceramics, electronic ceramics, advanced ceramics, synthetic mullite materials, enamel glazes, and specialty refractory products, demonstrating outstanding dielectric properties, thermal stability, electrical insulation, as well as excellent mechanical performance and superior resistance to high temperatures and oxidation. Ceramic products incorporating spherical silica fume become denser, more resistant to thermal and cold fatigue, and exhibit significantly improved strength. Meanwhile, when added to specialty refractory materials, spherical silica fume also exhibits exceptional flowability, sintering capability, bonding properties, and remarkable ability to fill porosity.
 
5. Coatings, Paint Fillers
 
Spherical silica powder also plays a vital role in the coatings and paints industry. Its unique physical properties and chemical stability make it an indispensable filler in these fields. High-purity spherical silica powder not only boasts special optical characteristics that conventional SiO₂ materials lack, but also exhibits exceptional UV absorption and infrared reflection capabilities. When added to coatings, it effectively creates a shielding effect, protecting against both UV-induced aging and thermal degradation while enhancing the coating's thermal insulation properties. In UV-curable coatings, incorporating high-purity spherical silica powder can significantly boost the hardness and adhesion of the paint, while simultaneously reducing its absorption of UV radiation—thus slowing down the curing process. Moreover, its exceptionally large specific surface area endows it with high reactivity, enabling it to form a robust network structure as the coating dries. This enhances the coating's strength and smoothness, improves pigment suspension, and ensures long-lasting color stability. In addition, spherical silica powder is crucial as a functional filler in paints and coatings, helping to elevate their overall quality by reducing shrinkage rates and viscosity, while simultaneously boosting wear resistance and storage stability.
 
6. Ink and Pigments
 
High-purity spherical silica powder exhibits excellent flowability and lubricity, enabling superior dispersion, suspension, and stability. When used in inks and pigments, this spherical silica powder allows for reduced ink and pigment quantities while still achieving high opacity, outstanding gloss, fine resin particle size, continuous film formation, and a smooth, uniform surface—resulting in thin, crisp printed images.
 
7. Optics and Optoelectronics Industry
 
High-purity spherical silicon micropowder is widely used in precision grinding applications within the optical and optoelectronic industries, making it particularly well-suited for grinding and polishing semiconductor single-crystal and polycrystalline silicon wafers, picture tube glass shells and screens, optical glass, glass substrates for liquid crystal displays (LCDs and LEDs), piezoelectric quartz crystals, compound semiconductor materials such as gallium arsenide and indium phosphide, and magnetic materials—among other key components in the semiconductor industry.
 
Currently, spherical silicon micropowder is increasingly being applied in high-tech fields, particularly in the packaging of large-scale integrated circuits and the IC substrate industry. Although angular silicon micropowder is more cost-effective, its poor flowability and tendency to damage molds make it difficult to meet the demands of both large-scale and ultra-large-scale integrated circuits. With the rapid advancement of microelectronics technology, market demand for spherical silicon micropowder is steadily rising, while quality requirements are becoming even more stringent. In epoxy molding compounds used for IC packaging, silicon micropowder accounts for as much as 70–90 wt%, and as integration levels continue to increase, the reliance on spherical silicon micropowder is growing stronger than ever.
 
III. Major Silicon Micropowder Manufacturers Globally
 
Well-known international companies include Japan’s Ryosan Company and Japan’s Electrochemical Co., Ltd., while domestically, industry leaders such as Jiangsu Lianrui New Materials Co., Ltd. and Suzhou Jinyi New Materials Technology Co., Ltd. stand out. These companies all play pivotal roles within their respective fields.
 
TATSUMORI Corporation of Japan
 
Founded in October 1963 and headquartered in Tokyo, Japan, the company is a leading global player in the field of electronic materials. Specializing in the research, development, and production of high-performance fillers such as silica, it holds a prominent position particularly in the spherical silicon micropowder market, jointly capturing over 70% of the global market share alongside companies like Denka and Nippon Steel. In the electronics materials sector, the company’s core product—spherical silicon micropowder produced via the flame fusion method—is renowned for its exceptional purity, low dielectric constant, and outstanding thermal stability. These qualities make it an ideal choice for advanced applications in areas such as integrated circuit packaging, copper-clad laminates, and epoxy molding compounds. For instance, its VX-SP glass powder, refined through an optimized crystallization process, significantly enhances the insulation properties, abrasion resistance, and arc-proof performance of epoxy resins, making it a crucial additive for high-end coatings and electronic encapsulation materials.
 
Longsen has established production bases and branches in Japan, Malaysia, Singapore, the United States, and other regions, creating a supply chain network that spans Asia and North America. Take its Malaysian subsidiary as an example—its revenue in 2022 grew by 39.98% year-on-year, demonstrating strong capabilities for market expansion.
 
In the field of electronic-grade silicon micropowders, Longsen has leveraged decades of process expertise to achieve breakthroughs in producing ultra-fine powders below 1 micron, positioning itself as a key player alongside companies like Yatuma in dominating the high-end market. Its products are widely used in core components of globally renowned electronics firms—such as semiconductor packaging materials, 5G communication devices, and battery components for new-energy vehicles—indirectly supporting the manufacturing of premium products from brands like Apple and Samsung.

 
Denka Co., Ltd.
 
Founded in 1915 and headquartered in Chuo Ward, Tokyo, the company is a comprehensive enterprise centered around the chemical industry, listed on the Prime Market of the Tokyo Stock Exchange (stock code: 4061). As of April 2025, the company’s registered capital stands at 36.998 billion yen, with a total workforce of approximately 6,514 employees across the group. Its business spans multiple sectors, including electronic materials, high-performance rubber, polymer solutions, and more. The company has established numerous subsidiaries and R&D centers worldwide, strategically located in Singapore, Malaysia, Vietnam, as well as in Shanghai, Suzhou, and Tianjin in China—forming an extensive Asia-based production and innovation network. To meet the growing demand from the xEV market, the company has jointly invested in building a 11,000-ton acetylene black plant in Thailand (expected to begin operations in 2026), while also doubling its investment in the silicon nitride powder project, further solidifying its leading position in the battery materials sector. In fiscal year 2024 (ending March 2025), the company reported a net loss of 12.3 billion yen due to losses incurred by its U.S.-based neoprene rubber subsidiary. However, through asset sales and other strategic measures, the company anticipates a turnaround in fiscal year 2025, aiming for a target net profit of 15 billion yen. Management emphasizes enhancing profitability via technological innovation and cost optimization, while maintaining a dividend policy of 100 yen per share. As a global leader in silicon nitride powder manufacturing, Nippon Denka leverages its century-old expertise in chemical technology to continuously pioneer breakthroughs in materials science. Its cutting-edge products—including high-performance ceramics and advanced thermal management materials—are not only tailored to meet the sophisticated needs of industries such as automotive and electronics but also provide innovative solutions for renewable energy and healthcare, making it a vital force driving sustainable societal progress.

 
Japan's Nippon Steel
 
A global leader in the steel industry, headquartered in Tokyo, the company was established in 1970 through the merger of Yahata Iron & Steel and Fuji Iron & Steel. In 2012, it further strengthened its global competitiveness after merging with Sumitomo Metal Industries. As of 2025, the company is listed on the Tokyo Stock Exchange (stock code: 5401) and operates across diverse sectors, including steel manufacturing, engineering services, and advanced materials research and development. In fiscal year 2024 (ending March 2025), the company experienced a 20.8% decline in net profit to JPY 549.4 billion, primarily due to sluggish global steel demand—though this still exceeded market expectations. For fiscal year 2025, the company anticipates a net profit of JPY 300 billion, largely driven by idle equipment costs and weak market demand. Through its subsidiary, NIPPON STEEL & SUMIKIN MATERIALS CO., LTD. P MICRON CO., the company pioneers the R&D and mass production of silicon micropowders using the world’s first industrial-scale application of the melt-spray method to create true spherical particles. This innovative technology involves high-temperature melting of silica followed by surface tension-induced spherification, resulting in spherical silicon micropowders characterized by uniform particle size distribution, exceptionally smooth surfaces, and excellent flowability. These powders also exhibit low dielectric constants, minimal thermal expansion, superior insulation properties, and outstanding resistance to high temperatures and oxidation. With purity levels exceeding 99.9%, certain product models—including the HS series—achieve SiO₂ purity as high as 99.99%. Moreover, these micropowders demonstrate remarkably low radioactivity, making them ideal for meeting the stringent material stability requirements of large-scale integrated circuit packaging. Nippon Steel, along with Japan’s Tatsuno Corporation and Denka, collectively holds over 70% of the global market share for spherical silicon micropowders, particularly excelling in the high-end electronic-grade segment, where technological barriers remain exceptionally high.
 
Japan Adumah (ADMAFINE)
 
The world's only company achieving large-scale production of spherical silicon micropowders with particle sizes below 1 micron, it employs a melt-based process that involves high-temperature melting of silica and leveraging surface tension to form perfect spheres. The resulting ADMAFUSE series products boast an exceptionally narrow particle size distribution (D50 = 0.8–30 μm), a sphericity of ≥0.95, and a purity level exceeding 99.99%. Moreover, these powders exhibit radioactive α-ray intensity below 1 ppb—making them ideal for advanced packaging applications such as Chiplet and HBM technologies. These ultra-fine powders deliver low dielectric loss (Dk < 3.0) and exceptionally high filling rates (>85%), effectively reducing the thermal expansion coefficient of chips while significantly enhancing signal transmission efficiency. As a key material for 2.5D/3D packaging, YADUMA’s sub-1-micron spherical silicon micropowders are specifically designed to fill the minuscule gaps between chips and substrates, supporting cutting-edge manufacturing processes at leading foundries like TSMC and Samsung. In epoxy molding compounds (EMC), YADUMA’s products account for over 60% of the market share, particularly dominating more than 80% of the high-end CPU and GPU packaging segments. Meanwhile, in copper-clad laminates (CCL)—critical components for 5G base stations and data centers—YADUMA’s spherical silicon micropowders help maintain a dielectric constant (Dk) below 2.8 and ensure transmission losses (Df) remain below 0.002, perfectly meeting the stringent demands for high-speed signal transmission from industry leaders like Huawei and ZTE. YADUMA currently holds over 90% market share in the sub-1-micron spherical silicon micropowder segment, firmly establishing itself as a global leader alongside Japan’s Ryosan and Denka, collectively commanding more than 70% of the high-end market. The significant technological barriers in this niche area have severely hindered domestic companies from making meaningful progress in import substitution, with only a handful of local manufacturers—such as Lianrui New Materials—currently capable of partially replacing products above 5 microns in size.
 
Jiangsu Lianrui New Materials
 
Mastering various spherical silicon micropowder preparation techniques, such as flame fusion and high-temperature oxidation methods, the company has applied for a patent in 2025 on ultra-low dielectric-loss spherical silicon micropowder. The CN silicon micropowder patent (CN119954165A) can reduce dielectric loss to industry-leading levels.
 
Product Applications: Micron- and sub-micron-sized spherical silica powder (D50 = 1–30 μm) is widely used in semiconductor packaging (accounting for over 70% of epoxy molding compounds), high-frequency, high-speed copper-clad laminates (substrates for 5G base stations), and thermal management materials for next-generation energy storage batteries.

 
Jiangsu Yake Technology (Huafei Electronics)
 
Technical Feature: Focused on the R&D of low-α spherical silicon micropowder, our product exhibits an α-ray radioactivity level below 0.1 ppb, meeting the stringent material stability requirements for advanced packaging applications such as Chiplet and HBM.
 
Capacity Layout: In 2024, we will launch a new generation of Low-α encapsulation powder with an annual production capacity of 20,000 tons. Key customers include leading global plastic encapsulant companies such as Sumitomo Bakelite and Hitachi Chemical.
 
Anhui Yishitong
 
Technological Breakthrough: Independently developed hollow silica spherical powder with a dielectric constant (Dk) ≤ 2.8 and a dissipation factor (Df) ≤ 0.002, delivering performance comparable to that of Japan's Adama.
 
Application areas: The product has entered Huawei's 5G base station supply chain, while achieving a global market share of 35% in the lithium battery coating materials sector, with deep collaborations alongside CATL and Samsung SDI.
 
R&D Investment: In 2024, R&D expenses accounted for over 8%, with a focus on developing nano-sized spherical silicon micropowder (D50 = 0.5–1 μm), targeted for application in quantum chip packaging.
 
Suzhou JinYi New Materials
 
Founded in 2005, JinYi New Materials is dedicated to providing cutting-edge application solutions for high-end inorganic non-metallic powder materials. As a national-level high-tech enterprise integrating R&D, production, sales, and technical services, the company boasts advanced spherical silicon micro-powder preparation technologies, including flame-synthesized spherical silicon, direct-burning spherical silicon, and chemically synthesized spherical silicon techniques. Notably, JinYi New Materials pioneered the world's first chemically synthesized spherical silicon technology, effectively circumventing foreign patent restrictions. The company’s ambitious 20,000-ton project in Yunyang, Chongqing, focused on developing high-end electronic functional materials, is set to begin production in March 2025. This initiative will primarily produce low-loss spherical silicon micro-powder (Dk ≤ 3.0) tailored for copper-clad laminates. Additionally, JinYi has established joint laboratories with Huawei and CETC to jointly develop next-generation high-speed communication materials, with its products already achieving automotive-grade certification.
 
Spherical silicon micropowder, as a key functional industrial material, boasts an exceptionally promising market outlook and immense potential for industry growth. According to statistics, the global annual demand for various types of spherical silicon micropowder is conservatively estimated to exceed 500,000 tons, with a total market value of approximately 40 billion yuan—and the market continues to expand at an annual growth rate of around 20%. Currently, however, foreign companies dominate the spherical silicon micropowder market, holding a monopolistic position. As a result, overcoming technological bottlenecks and achieving independent innovation have become critically important. Unfortunately, leading overseas manufacturers in Japan, the United States, and other countries maintain strict monopolies and export restrictions on the specialized production equipment and technologies required for manufacturing spherical silicon micropowder. Consequently, China has long relied on imports for high-end spherical silicon micropowder, which has significantly slowed down the development of domestically produced equipment and technologies in this critical area. Nevertheless, with the rapid expansion of China's semiconductor integrated circuit and electronic electrical component industries, the market demand for premium-grade spherical silicon micropowder is surging at an astonishing pace. To meet this burgeoning need and ultimately break free from the longstanding dominance of foreign products, it is essential for China to master advanced production technologies for high-quality spherical silicon micropowder—thereby paving the way for the sustainable growth and competitiveness of its domestic semiconductor and electronic industries.
 
Currently, the domestic silicon micropowder industry is characterized by a structure where "leading enterprises dominate the high-end segment, while emerging companies are rapidly catching up." Companies like Lianrui New Materials and Huafei Electronics have excelled in technological innovation and capacity expansion, gradually breaking the monopoly previously held by Japanese firms. Meanwhile, JinYi New Materials and Yishitong have achieved import substitution through differentiated technology strategies, while regional players such as the Sanmenxia project are leveraging favorable policies to accelerate production capacity deployment. Looking ahead, with the advancement of 5G, AI, and new energy technologies, domestic enterprises must continue making breakthroughs in areas like ultra-fine powders (below 1 μm) and high-frequency, high-speed materials. At the same time, they need to strengthen green manufacturing practices and foster greater collaboration across the industry chain to meet rising international competition and evolving market demands.