Glass soldering

GLASS SOLDER AREA COVERED BY LEAD AZIDE... 

Glass solders and sealants for glass-to-glass joining and hermetic glass-to-metal sealing... 

Reactions of the hydroperoxides eatalytic decomposition were carried out in glass-soldered ampoules in argon atmosphere. To control the proceeding of hydroperoxides thermolysis and their deeomposition in the presence of Et NBr the iodometric titration with potentiometrie fixation of the equivalent point was used. 

After applying the spacers, the substrates with their electrode structures are aligned and then hermetically sealed. When foil or varnish is used as spacer material, the substrates are best sealed with an adhesive such as epoxy. With metal spacers the substrates are simply soldered together. Wlien using glass solder as spacer, the plates printed with glass solder frames are pressed together and heated. 

As mentioned previously, Schiff bases are chemically relatively unstable. This is especially true of d.c. driven cells incorporating components that favor liquid crystal decomposition. Using the glass solder technique in cell manufacture substantially improves the stability of Schiff bases. The stability of Azoxy-compounds and nematic ester, of which the latter has only been available more recently, is hardly affected by the cell components. 

Quasi-nondestmctive techniques include several transport measurements that are used to test specific membrane properties. They require sample mounting by compression sealing or glass solders that rarely leave the dehcate membrane surface intact. Gas transport properties of dense and microporous membranes are tested by measuring single gas ji as a function of and and by obtainmg fluxes and a/,from the stationary composition and flow rate of gas mixtures at the membrane feed and permeate side. To use the results of these measurements for comparison and optimized membrane designs, substantial... 

The maximum joining temperature is given by the material of the parts to be joined and the actual use conditions of the joined device. It is advised to use the lowest possible joining temperature. In praxis the thermal expansion coefficient of the glass solder is linked reciprocally to the joining temperature [397], A lower thermal expansion coefficient of the glass requires that the joining temperature increases frequently. 

Composite glass solders consist of a glass phase and a crystalline phase with a low thermal expansion coefficient. The crystals are inert and dispersed in the glass phase. The thermal expansion coefficient of the composite is given by the rule of mixture of the thermal expansion coefficient of the glass phase and the inert crystalline phase. The addition of the crystalline phase allows to tailor the thermal expansion coefficient of the solder at given soldering... 

Fig. 7.9 a) The attachment of the measurement sample to a ZrOg tube (using a suitable glass solder) permits the direct determination of the ionic transference number from the ceU voltages at the tube and the sample, b) Heuristic equivalent circuit referring to Ekj. (7.36). 

---