Fabrication of quartz diaphragms for helium leak detection

The feasibility of 50 μm thick diaphragms with a metallic film heater integrated on a quartz disc and working up to 500 °C has been demonstrated. The diaphragms have been realized with the coupling of abrasive jet machining and mechanical polishing techniques. The metallic film has been obtained by means of a sequence of e-gun evaporation and electrochemical growth steps. No degradation of the adhesion characteristics was registered. Electrical properties were retained without electro-migration even for working conditions of 50 h at 500 °C. Aim of the device is the application in quartz molecular sieves thermally/electrically modulated, basically for helium leak detection.