PEEK Screws in Semiconductor Equipment - High Purity, Low Outgassing | FASTKING Case
Case Background
A semiconductor equipment maker's wafer transfer end-effector operates in a 200°C vacuum chamber. Original SUS316L stainless steel screws caused three problems: continuous outgassing in high vacuum (hydrocarbon contamination), particle release exceeding the fab's 0.3 µm cleanliness requirement, and thermal expansion mismatch with the ceramic chuck leading to loosening.
Solution
FASTKING supplied peek (polyetheretherketone) screws as a replacement. peek is among the highest-performance engineering polymers: continuous service temperature 260°C (short-term 300°C), outgassing in 10⁻⁶ Pa vacuum 1/100-1/1000 of metal, and natural-resin purity meeting SEMI E12.
Specifications
- Material: PEEK 450G (Victrex equivalent), natural beige
- Sizes: M3×6 / M4×8 / M5×10 hex socket cap head
- Performance: tensile strength 95 MPa, continuous 260°C, CTE 23×10⁻⁶/°C
- Cleanliness: particle release < 0.2 µm, outgassing TML < 0.5%, CVCM < 0.05% (NASA E595)
Results
Over 8 months, FASTKING delivered 120,000 peek screws to this customer:
- Vacuum chamber particle count dropped from 12/m³ to 1/m³ — a tenfold cleanliness improvement.
- Customer yield improved from 96.5% to 98.2%.
- CTE matches the ceramic chuck, with no loosening under thermal cycling.
- The customer has now adopted PEEK fasteners across its PVD, CVD and ETCH equipment platforms.
Contact the FASTKING engineering team for samples or cleanliness test reports of semiconductor-grade PEEK/PI/PPS fasteners.