An electroplated cobalt-tungsten cathode on a screen-printed nickel film and mercury processes for a dc-type plasma display panel (PDP) were examined. The nickel film cathode was electroplated after a thermal process in air. Two mercury methods, a conventional mercury-capsule method and a method of dipping in mercury immediately after plating were examined. At the same applied voltage, the discharge current of the panels with electroplated cathodes was higher than the current of panels without electroplating. These results were independent of the mercury process. The electroplated cathode made with the mercury-immersion process exhibited the highest brightness. For the electroplated cathode with Hg-capsule process, a sputtered materials attached to the inside of the window glass and they decreased brightness. Therefore, the mercury immersion process was suitable for electroplated cathodes. Since the surface of the electroplated cathode was active, it reacted with the mercury uniformly. The discharge waveforms of the panels showed a sharp onset and offset. Good chromaticity and the fast response that was advantage of the PDP were maintained. Therefore, electroplating on a cathode thick film was advantageous not only for the method of preparing cathodes, but also for the method of evaluating cathode materials.
The feasibility of the electroless plating of Pd onto ZrO2 powder from a bath containing thiodiglycolic acid and ethylenediamine and using sodium hypophosphite as a reducing agent has been demonstrated Sintering of the deposited Pd on ZrO2 occurred at about 900°C, considerably higher than the 550°C sintering temperature of pure Pd powder, and this was attributed to the presence of thermally stable ZrO2 in the interstices of the Pd deposits, interfering with Pd atom migration When heated in air, the deposited Pd began to oxidize at 280°C, about 220 deg lower than did the pure Pd powder This was due to the smaller particle size, for when particle size was increased by sintering, the oxidation temperature was found to be the same as pure Pd powder
An electroless copper plating method using EDTA (ethylenediaminetetraacetic acid) as a complexing agent and HCHO as a reducing agent has been studied. Additives used were 2, 9-dimethyl-1, 10-phenanthroline (2, 9-dmph) and 5, 6-dimethyl-1, 10-phenanthroline (5, 6-dmph). The working mechanism of 2, 9-dmph, which had a cuproine functional group, was the reiteration of the following three steps: 1. adsorption of 2, 9-dmph on the copper working electrode; 2. production of Cu (I) (2, 9-dmph)2 complex on the electrode; and 3. transference of the Cu(I)-complex to the plating solution. As a result, 2, 9-dmph prevented the active alcoholate ion from being adsorbed on the working electrode. Since the characteristic wave disappeared, polarization characteristics were explicable by the mixed potential theory, and copper complex ion Cu (II)Y2- was directly reduced to metallic copper. The surface of the deposit was uniform and the grains were linked. The cross section of the deposit was virtually identical to that of metallic copper. In the case of 5, 6-dmph, which had a ferroine functional group, copper complex Cu (I) (5, 6-dmph)2 formed on the electrode failed to transfer to the plating solution, and the mixed potential theory did not hold. The deposit was amorphous. The surface of the deposit was rough and the cross section was spongy.
The effects of suspending PTFE particles in an electroless Ni-P plating solution, and of the quantity of particles in the deposit were studied in relation to anionic, cationic and non-ionic surfactants. It was found that the suspention of PTFE particles in the bath was effected by non-ionic and hydrocarbon series surfactants, but not by others. It was confirmed that PTFE particles are not codeposited into the matrix by adding only a non-ionic surfactant, but are uniformly codeposited by adding both non-ionic and cationic surfactants.
Ultramicrotomy was employed to prepare thin cross-sections of the barrier oxide films grown on etched aluminum foils for capacitor applications. It was found that the sections as thin as 10nm could be prepared successfully. Examination of the ultramicrotomed sections by transmission electron microscopy revealed a number of important structural features of the films that have not been reported previously. Of particular importance is that the nature and origin of film defects have been clarified and classified for the first time.