Analysis Of Quartz Fiber Production Process And Standard Parameters
In the wave of AI computing power, high-speed communication, and high-end PCBs, quartz fiber has moved from behind the scenes to the forefront. As a core raw material for ultra-high purity SiO₂ fiber and Q-cloth, a top-tier material for electronic fabrics, it has become a key support for NVIDIA's GB200, 1.6T optical modules, and 6G communication due to its superior dielectric properties, ultra-high temperature stability, and low thermal expansion. This article explains the essence of quartz fiber products from three aspects: industrial-grade manufacturing processes, core material characteristics, and standard technical parameters.
I. Industrial Manufacturing Process of Quartz Fiber
The production of quartz fiber has extremely high requirements. The rod drawing method is the mainstream industrial method globally (and is also used by most domestic companies), with strict control over purity, temperature, and diameter throughout the entire process.
1. Raw Material Selection and Pretreatment
- Raw materials: Natural crystal/high-purity quartz sand, SiO₂ ≥ 99.95%~99.998%, alkali metals (Na/K/Li) < 10ppm, zero bubbles, zero impurities.
- Pretreatment: Crushing → Acid washing → High-purity water washing → Drying, thoroughly removing mineral impurities and metal ions.
2. Quartz Master Rod Preparation (Core Pre-process)
- Raw materials are fed into a vacuum pressure resistance furnace and melted at 2000~2300℃ to remove bubbles and homogenize composition.
- Continuously drawn into φ1.8~2.5mm quartz rods, serving as the master material for fiber drawing, in a dust-free and contamination-free process.
3. High-Temperature Melting and Fiber Drawing (Core Process)
- Quartz rods are fed into an oxyhydrogen flame/electric heating furnace and melted and softened at 2230~2600℃.
- The bottom "fiber root" melts and is drawn at high speed into monofilaments with a diameter of 5~9μm (7μm is commonly used for electronic grade, tolerance ±0.5μm).
- Online coating with a special sizing agent (starch/epoxy type) to protect the fibers, prevent fuzzing, and adapt for subsequent fabric weaving.
- Far-infrared drying → winding into bobbins, with precise control of linear density (Tex).
4. Subsequent Processing (Yarn/Fabric/Felt)
- Raw yarn plying and twisting: producing standard electronic yarns such as 4.9Tex and 9.8Tex.
- Fabric weaving: high-precision rapier looms to weave quartz electronic fabric, also known in the industry as Q-fabric (standard specifications such as 1080/2116/7628).
- Deep processing: can be chopped, felted, and surface modified, suitable for copper-clad laminates and composite materials.
II. Five Core Characteristics of Quartz Fiber
1. Ultra-high purity
- SiO₂ ≥ 99.95%, up to 99.998%, total impurities < 50ppm.
- Free of boron, aluminum, calcium, and other metal ions, achieving low dielectric constant, low loss, and high insulation from the source.
2. Exceptional Dielectric Performance
- Dielectric constant (Dk) ≈ 2.2~2.3 (10GHz), only 1/3 that of E-glass fiber (≈6.0).
- Dielectric loss (Df) ≈ 0.0001~0.0002, signal loss is almost zero.
- Wideband (1MHz~100GHz) stability, compatible with 1.6T/800G, AI servers, and 6G.
3. Ultra-High Temperature and Thermal Stability
- Long-term operating temperature up to 1050℃, instantaneous temperature resistance up to 1700℃ (softening point).
- CTE ≈ 0.54ppm/℃ (approaching zero thermal expansion), compatible with silicon chips, PCB does not warp.
- ≥80% strength retention at 1000℃, resistant to thermal shock and sudden temperature changes without cracking.
4. High Strength and High Modulus
- Tensile strength 1500~2000MPa, modulus 70~90GPa, high strength and lightweight.
- Resistant to strong acids, strong alkalis, and organic solvents; does not decompose at high temperatures and produces no volatiles.
5. High Transmission and Insulation
- Radar wave/microwave transmittance ≥99%, suitable for radomes and radar compartments.
- Volume resistivity 10¹⁶~10¹⁸Ω·cm, excellent high-temperature insulation.
III. Standard Technical Parameters of Electronic Grade Quartz Fiber
1. Basic Composition and Physical Parameters
- SiO₂ Content: 99.95%~99.998%
- Density: 2.20 g/cm³
- Single Filament Diameter: 5/7/9 μm (7 μm is the mainstream for electronic grade)
- Linear Density: 4.9 Tex, 9.8 Tex, 13.1 Tex
2. Thermal Parameters
- Long-term Operating Temperature: 1050℃
- Softening Point: 1700℃
- Coefficient of Thermal Expansion (CTE): 0.54 × 10⁻⁶/℃
- Thermal Conductivity: 0.03~0.05 W/m·K (High-efficiency thermal insulation)
3. Electrical Parameters (10GHz)
- Dielectric Constant Dk: 2.2~2.3
- Dielectric Loss Df: ≤0.0002
- Volume resistivity: ≥10¹⁶ Ω·cm (room temperature)
4. Mechanical Parameters
- Tensile strength: ≥1800MPa
- Elastic modulus: ≥70GPa
- Elongation at break: 3%~5%
Quartz fiber is the culmination of high-purity materials, extreme processes, and precise control: from ppm-level purity control, 2600℃ high-temperature drawing, micron-level diameter tolerance, to a low-dielectric-stable system, every step represents a technological high barrier. It is not only the ultimate upgrade of E-glass fiber, but also an essential material for AI servers, high-speed PCBs, and 6G, becoming an invisible cornerstone of high-end electronics and advanced manufacturing.
