Abstract: A method and an apparatus for cutting insulating material (e.g., quartz) having a conductive layer on the surface thereof includes the use of a thin copper wire having diamond particles imbedded therein. The wire is moved in a direction perpendicular to the surface of the material. A source of potential is coupled between the wire and the layer, and a liquid solution is supplied between the wire and the conductive layer resulting in electro-erosion of portions of the layer proximate to the wire. A tension sensor detects wire displacements at the quartz cutting site and controls a wire-to-layer gap detector which in turn interrupts the displacement of the insulating material.

Abstract: An hermetically sealed envelope comprises a base having a groove therein, a tubelike cover inserted within the groove, and a sealing member surrounding the cover within the groove. A cold weld between the member and the cover is achieved by permanently deforming the member within the groove. A vacuum-tight seal is thereby achieved in the field without the use of heat, large force, sealants or adhesives.