Image Number 4 for United States Patent #4500383.
A process for bonding a copper or copper-chromium alloy body and a ceramic body of components of an electrical or electronic device to each other includes a step of directly sandwiching a layer of chromium oxide between the ceramic and copper or copper-chromium bodies, a step of heating a temporary assembly of the ceramic and copper or copper-chromium alloy bodies and the layer of chromium oxide, under an atmosphere which can oxidize chromium without oxidizing copper, at a temperature of at least 900.degree. C. but below the melting point of copper or the alloy, and then a step of slowly cooling the resulting bonded assembly. In particular, in a process for bonding the alloy body to the ceramic body, the chromium oxide sandwiching step is performed concurrently with the temporary assembly heating step. The bonding process can produce a hermetic envelope, particularly a vacuum envelope of a vacuum interrupter. The process for bonding the copper or alloy body to the ceramic body of this invention is more advantageous than bonding processes employing the so-called Telefunken method, in terms of cost and steps.