Multi-Pin Feedthrough Sensor

Technical Requirements

• The threaded hole at “I”, the three-electrode connecting tab and the center of the adapter’s outer groove must align on one straight line during welding.
• Bake at 350°C with a leak rate ≤1×10⁻¹³ Pa·m³/s. Ramp at 1°C/min to 350°C, hold for 6 h and verify that the leak rate remains unchanged after cooling. Use the customer’s leak detector as the acceptance reference and provide a test report.
• Electrode-to-ground resistance must prevent electrical leakage; the central-electrode shield, ground electrode and feedthrough shell must have electrical continuity.
• Maintain electrode positional accuracy to match the customer’s acceptance fixture, allowing smooth insertion and removal; repeated cycles must remain leak-tight (≤1×10⁻¹³ m³/s; Pa is not stated at this location in the source).
• Seal all Kovar-to-ceramic interfaces by welding. Vacuum-side surfaces must be free of oil and particles; electrode pins must be free of excess filler metal.
• Weld along the indicated seam for sealing; make four equally spaced intermittent welds where indicated and grind the outer surface smooth. Use a continuous internal weld for sealing.
• The indicated electrode top is below the adapter; A-A is a sectional view.
• 01 adapter: Φ43.6×Φ38×21.5, 304 stainless steel; 02 body: Φ38.7×31, ceramic and Kovar.
• 03 retaining sleeve: Φ44×Φ24×33, 304 stainless steel; 04 CF35 internal-weld flange: Φ70×Φ38×13, 304 stainless steel; one of each per assembly.