Manufacture And Properties Of Photosensitive Silver Paste

Photosensitive silver paste is a novel material, which uses as electrode in PDP. It not only improves the precision of electrode, but also decreases the cost of equipments. In the paper, the formulas of ultrafine glass powders, preparing methods of ultrafine silver powders, characteristic of organic carrier and photosensitive systems were investegated.A series of PbO– SiO2– B2O3 glass and PbO– SiO2– B2O3– ZnO glass were prepared by melting mixture of PbO,SiO2,H3BO3 and ZnO powder at 980℃. The structure of PbO– SiO2– B2O3 glass was confirmed by FTIR. The density of glass powder decreased with the increase of B2O3 content. Reversely, that increased with increasing of PbO content. PbO– SiO2– B2O3 glass had excellent chemical stability. With the increase of weight ratio of SiO2/B2O3, the soft point decreased.Formaldehyde-silver ammonia solution was applied as silver-plating solution. The influences of the pH value, stabilizing agent and bath temprature on silver plating had been investigated by measurement of the silver content on the surface of glass powders and scanning electronic microscope (SEM). The results indicated that the amount of deposited silver increased with increasing the concentration of NaOH in plating bath, and the silver depositing out of the surface of glass powders might be prevented by adding stabilizing agent into the bath. By adjustment of bath temprature, the thickness of silver coating can be controlled in the range 50nm.The ultrafine silver powders were prepared with H2O2 as reducing agent. The size and shape of silver powders were determined with TEM, XRD and SEM. The results showed that the size and shape of the ultrafine silver powders varied with reaction conditions and the ultrafine silver powders possessing 450nm diameter could be obtained in microemulsion with OP emulsifying agent.The volatility of the organic carrier used as photosensitive silver paste was studied. The drying curve of mixing organic solution was simulated. The effect of different solvents on volatility of carrier was investigated. A kind of carrier having gradual volatility was prepared. When proper additives were added into used the organic carrier, the proprieties of the organic carrier became more excellent.In addition, the process forming electrodes of PDP with photosensitive pastes was investigated, and better results had been obtained.