Effects of Sol-Gel Treatment and Plating on the Electrical Properties of Multilayer Filters

The effects of sol-gel treatment and plating on the electrical properties of multilayer filters were investigated. The results showed that the sol-gel treatment process can effectively lower the apparent porosity of multilayer filters, preventing the penetration of electroplate liquid into the filters. The mean insertion loss rise for the sol-gel-treated components was 0.171 dB, which increased up to 0.811 dB for the filters without sol-gel seal treatment. Microstructural studies revealed that the sol-gel seal treatment is an effective preplating treatment to diminish the insertion loss of multilayer filters.