CF-35 Vacuum Sight Glass (CF35 Viewport) — UHV Vacuum Viewport
CF-35 Vacuum Sight Glass — compact CF-flange vacuum viewport (CF35) for high- and ultra-high-vacuum systems. Metal-sealed optical window for real-time observation of vacuum chambers, scientific instruments and UHV process tools.
Description
CF35 vacuum sight glass (CF35viewport) is a compact ConFlat® (CF)-flanged vacuum viewport designed for high-vacuum and ultra-high-vacuum systems. These viewports use a metal-to-glass (Borosilicate / Quartz (Fused Silica) / Sapphire / Barium Fluoride / Calcium Fluoride / Zinc Selenide) sealed construction that preserves UHV integrity while providing optical access for process monitoring, alignment, and inspection. Typical materials include stainless steel housings with sapphire, quartz (fused silica), or high-grade borosilicate windows.
Key Benefits
- ConFlat® CF-35 flange — compatible with standard CF hardware for HV/UHV systems.
- Metal-to-glass / metal-to-sapphire seal — UHV-compatible sealing method (low outgassing and low leak rate).
- Material options — optical borosilicate, fused silica (quartz) for UV, or sapphire for the highest mechanical/thermal robustness.
- Ultra-low He leak performance — factory Helium-leak tested and supplied with test report upon request.
- Custom drawings & small-batch manufacturing — CAD/DWG available; custom view diameters and coatings on request.
Why choose the CF 35 viewport？
CF-35 viewports let engineers add reliable optical access to compact vacuum systems without compromising vacuum performance. Choose sapphire for maximum mechanical and thermal durability (e.g., harsh bakeouts, plasma exposure). Choose fused silica (quartz) for optimal UV transmission (laser alignment, UV spectroscopy). Provide your expected operating temperature, bakeout profile and radiation exposure and we’ll recommend the ideal window material and coating.
Typical Technical Specifications
| Product model | CF35 |
|---|---|
| Product vacuum degree | 1E*10-12 pa·m³/s |
| Flange material | 304 / 316 |
| Glass material | Borosilicate / Quartz (Fused Silica) / Sapphire / Barium Fluoride / Calcium Fluoride / Zinc Selenide |
| Surface quality | 60/40, 50/20, 20/10 |
| Optical surface type | 1/2 – 1/10 |
| Visible diameter (mm) | 27 |
| Heat resistance range | 150 ～ 230℃ |
| Surface treatment | Electrolytic polishing |
| Transmittance | 1.45 ～ 1.57 |
| Outer diameter (mm) | 70 |
| Inner diameter (mm) | 27 |
| Thickness (mm) | 12.5 |
| Number of holes (pieces) | 6 |
| Through hole diameter (mm) | 6.6 |
| Glass thickness | 6 |
| Weight（g） | 262.5 |
| Specifications | A | B | C | P.C.D | material |
|---|---|---|---|---|---|
| CF16 | 33.8 | 7.5 | 4.4*6 | 26.9 | SS304/316 |
| CF25 | 54 | 10.5 | 6.7*6 | 43 | SS304/316 |
| CF35 | 69.5 | 12.7 | 6.7*6 | 58.7 | SS304/316 |
| CF63 | 113.6 | 18 | 8.4*8 | 92.1 | SS304/316 |
| CF100 | 151.6 | 20 | 8.4*16 | 130.3 | SS304/316 |
| CF150 | 181 | 22 | 8.4*20 | 202.5 | SS304/316 |
| CF200 | 253.2 | 24.7 | 8.4*24 | 231.8 | SS304/316 |
| CF250 | 336.5 | 28.5 | 10.3*30 | 306.5 | SS304/316 |
| CF300 | 355.6 | 28.5 | 10.3*30 | 325.7 | SS304/316 |
| CF350 | 419.1 | 28.5 | 10.3*36 | 388.9 | SS304/316 |
Applications & industries
- Semiconductor process chambers & load-locks (optical alignment & inspection).
- Vacuum coating and thin-film deposition systems (monitoring & process control).
- Research & R&D vacuum apparatus (spectroscopy, ion sources).
- Analytical equipment (mass spectrometers, surface analysis).
