This category covers the five components that make up the thermal field inside a Czochralski silicon puller — support ring, support rod, crucible holder, main heater, and furnace base tray — working together as one system to grow a defect-free monocrystalline ingot from a rotating silicon melt held above 1414°C for the full length of a pull run.
The crucible holder carries the quartz crucible and its molten silicon charge, while the support rod and ring transmit rotation and axial load without shifting the hot-zone geometry that governs crystal quality.
Consistent axial and radial temperature control from this thermal field set directly affects ingot yield and defect density, which in turn drives wafer cost and quality for solar module manufacturers.
Integrated circuit and power device manufacturers pull silicon to tighter resistivity and defect specifications, placing extra demand on thermal field purity and temperature uniformity that this component set is built to meet.
The same thermal field architecture extends to GaAs, InP, and SiC crystal pulling systems, as well as research-scale furnaces that need custom crucible and rod dimensions.
Every ring, rod, holder, heater, and base tray in this category is built on a decade of fiber architecture, densification, and purity-control experience carried across the company's full thermal-field product range — then refined further for the specific structural and electrical demands of a Czochralski puller.
Densification and graphitization know-how developed for polycrystal furnace parts and vacuum furnace heaters feeds directly into how the support rod, crucible holder, and main heater are engineered for the Czochralski process.
Ten years of matching flat lamination, winding, and compression-molding routes to specific load paths means each component — from a bending-loaded support ring to an axially wound support rod — is built for how it is actually stressed in service.
Long-running work supplying photovoltaic and semiconductor customers has shaped the ≤200 ppm ash-content standard applied uniformly across all five thermal field components, eliminating differential contamination risk within one furnace.
Preform fabrication, densification, graphitization, and precision machining are all handled in-house, so process improvements made for one component — such as resistivity control on the heater — can be traced and applied consistently.
Every component in this thermal field set moves through the same structured production sequence, with ash content, density, and dimensional accuracy verified batch by batch so that a support ring, crucible holder, or main heater leaving the factory has already been checked against the property spec its role in the furnace requires.
Non-woven and woven carbon fiber mats are laminated, wound, or compression molded into the target ring, rod, holder, or heater blank.
Needle-punching locks fiber layers together through the thickness, giving the preform interlayer strength before densification.
Chemical vapor infiltration and liquid-phase impregnation, used singly or combined, build density incrementally over multiple cycles.
Heat treatment above 2000°C reduces ash content to ≤200 ppm and sets the conductivity and resistivity each component requires.
CNC and diamond tooling cut crucible-seating features, mating surfaces, and final dimensions to close tolerance.
Density, strength, ash content, resistivity (heater and base tray), and dimensional checks confirm every batch against spec.
Production is vertically integrated — in-house preform fabrication, multi-route densification, high-temperature graphitization, and precision CNC machining under one facility — which shortens lead times and keeps process traceability intact from raw fiber through to a finished, furnace-ready component.
Why use carbon-carbon composite instead of graphite for a Czochralski thermal field?
C/C composite is lighter than high-density graphite, retains mechanical strength at temperatures where metals lose load-bearing capacity, and offers a coefficient of thermal expansion that better matches the conditions around a silicon melt. This combination reduces thermally induced stress cracking over the length of a pull run compared with graphite alone.
How does thermal field purity affect crystal quality?
Metallic impurities transferred from furnace components into the silicon melt degrade electrical resistivity and minority carrier lifetime in the finished crystal. Holding ash content at or below 200 ppm across the support ring, rod, crucible holder, heater, and base tray keeps contamination risk consistent across every part touching the process.
Can the crucible holder be custom-made to fit a specific crucible size?
Yes. The crucible holder is produced through compression molding, which allows the seating geometry to be shaped to a customer's specific crucible dimensions, making it compatible with a broad range of puller furnace configurations rather than a single fixed size.
Why does the main heater need a specified resistivity value?
Resistivity determines the power density delivered per unit surface area at a given drive current. A heater with resistivity poorly matched to the power supply creates localized hot spots or forces sub-optimal operating currents, either of which can distort the axial temperature gradient and increase crystal defects such as dislocations and oxygen striations.
What temperature and load conditions are these components rated for?
The components are engineered for continuous operation around and above the 1414°C melting point of silicon, with the furnace base tray and support ring built to carry the combined deadweight of crucible, melt, and thermal field structure — which can reach several hundred kilograms in large-diameter furnaces.
How does the ordering and customization process work?
Customers typically share furnace model, crucible dimensions, or target operating parameters (temperature, load, power supply rating). These are matched to a component design, density grade, and dimensional spec before production tooling is set up, so the finished part fits the intended puller from the start.
