摘要 |
A subminiature circuit protector includes a substrate (18) carrying a metal fuse element (20) hermetically sealed in a glass sleeve cartridge (30). The fuse element may comprise a film deposited on the substrate, or, alternatively a metal strip or wire. Leads (40, 42) extend from opposing ends of the sleeve for connection in a circuit, and a gas is sealed in the sleeve to provide a suitable environment to improve operating lifetime and interrupting capability. The circuit protector is made by placing the substrate (18) carrying the fuse element (20) in the glass sleeve (30) and placing the leads in contact with the fuse element. The assembly is heated in the presence of a gas below atmospheric pressure to a temperature sufficient to soften the glass. The pressure is then increased to cause the ends of the glass sleeve (30) to form a hermetic seal about the leads (40, 42). |