The traditional diode gas discharge tube includes two metal electrodes, two solders, and one ceramic insulative tube covered with a metallization layer, which are sealedly connected to form a discharge gap, where the electrodes are coated with a cathode emission material, and the ceramic insulative tube is provided with two or more trigger conductive strips. As shown in FIG. 1, the traditional diode gas discharge tube includes two metal electrodes 1, two solders 2, and one ceramic insulative tube 3 covered with a metallization layer, where the ceramic insulative tube 3 is provided with at least two conductive strips 31.
A process for manufacturing the traditional diode gas discharge tube includes that:
a bar or sheet material is mechanically stamped, then chamfered, polished and cleaned, to form the metal electrodes;
ceramic particles are mixed with an organic matter to form a slurry, which is subjected to dry pressing or injection moulding and to low-temperature binder removal, then sintered at a high temperature of 1400°, and smoothened, to form the ceramic insulative tube;
the ceramic insulative tube is subjected to screen printing, low-temperature curing and sintering at about 1300°, and then plated with nickel, to form the metallization layer;
a solder alloy is formed by smelting at a high temperature of about 1200° and then annealed to form a block-shaped alloy, which is in turn laminated and stamped to form the solders;
the trigger conductive strips are formed by drawing with a pencil; and
the electrodes are cleaned and coated with the cathode emission material, and then are assembled with the metallized ceramic insulative tube and the solders in a mold, and the assembled electrodes, metallized ceramic insulative tube and solders are placed in a vacuum seal furnace, which is subjected to gas discharging to form vacuum therein, is injected with a gas, and is raised to a temperature of about 850°, so that the electrodes, the metallized ceramic insulative tube and the solders are brazing welded at a high temperature, and are sealedly connected, thus a semi-finished product is formed after cooling, and the semi-finished product is aged, cleaned, plated, printed, and tested to obtain the resultant qualified product.
The gas discharge tube with the traditional structure has a poor discharge effect, and is disadvantageous in manufacturing for its complicated structure. For example:
the raw material used for manufacturing the traditional gas discharge tube need be processed in many steps, and therefore causes a high cost;
the metallized ceramic insulative tube is twice subjected to the high-temperature sintering at 1000° or higher, and the solders are subjected to the high-temperature smelting at 1000° or higher, so that the energy consumption for the raw materials is high; in addition, the resultant product is obtained by the sealed connecting at a high temperature of about 850°, therefore, all these three times of high-temperature sintering in the manufacturing process are disadvantageous for energy saving and emission reduction;
the numerous steps in the manufacturing process for the traditional gas discharge tube require for large investment in equipment and manpower, resulting in a high cost;
it is difficult to achieve the miniaturization and integration of the product; for example, to manufacture a multipolar integrated gas discharge tube, the raw material as required and the cost are increased by times, illustratively, as shown in FIG. 2, a gas discharge tube with four grounding ends that is manufactured by the traditional gas discharge tube manufacturing process typically includes 13 components, i.e. five electrodes 4, six solders 5, and two ceramic insulative tube 6 provided with a metallization layer 61; and
the numerous steps in the manufacturing process for the traditional gas discharge tube and the poor precision of processing the raw material lead to significant fluctuation of parameters of the gas discharge tube.