Field-assisted bonding method and articles produced thereby

Claim 1

Method of manufacturing an article comprising a "cell", the cell comprising a first and a second inorganic insulator body, the insulator material having a softening temperature or a melting temperature, each insulator body having at least one substantially plane major surface, the first insulator body bonded to the second insulator body, with the major surfaces opposed and with a predetermined spacing between the opposed major surfaces, the spacing to be referred to as the "cell thickness", characterized in that the method comprises (a) forming a layer of bonding material on the major surface of the first insulator body such that part of the major surface is free of bonding material, the bonding material chosen from the group consisting of those metals and semiconductors that have a melting point greater than about 250° C., the layer thickness being substantially equal to the cell thickness; (b) forming a combination by placing the major surface of the second insulator body into contact with the layer of bonding material; (c) heating the combination to a bonding temperature and applying a voltage across the heated combination for a time sufficient to result in bonding of the second insulator body to the bonding material to form the cell of predetermined cell spacing, the bonding temperature being lower than the melting temperature of the bonding material and the softening or melting temperature of the insulator material, the bonding temperature also being high enough to render the heated first and second insulator bodies sufficiently electrically conductive to permit some current to flow in response to the applied voltage, the applied voltage being such that the second insulator body is negative with respect to the bonding material layer for at least part of the time the voltage is applied.