METAL-TO-GLASS-TO-CERAMIC SEAL

摘要

A metal-to-glass-to-ceramic seal comprising a metal member including elongated portion and enlarged portion, a glass member bonded to the metal member and a ceramic member bonded to the glass member. The ceramic member is in close proximity to part of the elongated portion of the metal member and over the enlarged portion so as to help protect the glass member from stresses resulting from bending of the metal member, to help prevent the metal member from being separated from the seal by an external tensional force, and to direct compressive forces that are parallel to the axis of the metal member such as crimping forces to the metal member rather than exerting shear forces on the glass bonds. Part of the ceramic member of the seal may be metalized with a refractory metal to facilitate the joining of the seal to the device to be sealed. Use of a refractory metal for metalization of the ceramic member imparts several advantages to the seal including replacement of a portion of higher cost noble metals typically used, ability to bond the metal to the ceramic member and fire the ceramic member at the same time, a strong diffusion bond between the ceramic member and the metal layer that is substantially chemically resistant to most common electrolytes used in electrical devices, and ability to fuse a thin noble metal layer to the refractory metal metalized layer which reduces leaching during the joining of the seal to the electrical device.