Glass-to-Metal Sealing of Reed Switches
Two reed blades and a glass tube with matching coefficient of thermal expansion, injected with a special mix of inert gases are the materials that are required for the reed switch sealing process. The actual sealing process can be accomplished by using any of the different heat sources ranging from wire-wound heaters, band heaters, infrared lamps, or lasers. The two reed blades are inserted into either ends of the open glass tube and are then brought closer to make contact. After this step, the gap is calculated and one of the reed blades is moved back. This is the point at which the gas is turned on and the heating cycle seals the two ends of the glass tube. Finished reed switches are then tested for hermetic seal integrity and sent for further inspection.