| 摘要 |
PURPOSE:To form a dielectric layer having smooth surface and uniform film thickness so as to make ion generating quantity uniform by heating and curing a dielectric paste layer and thereafter smoothing the surface by abrasive grains having diameter below a specific average grain diameter. CONSTITUTION:In between patterns of a first electrode 2 and on the first electrode 2, dielectric paste having titanium oxide as a filler is applied and heated. After solvent included in the dielectric paste is volatilized and removed, it is further heated and cured so as to form a dielectric layer 3. In between the cured dielectric layer 3 and a support board, polishing liquid in which abrasive grains consisting of aluminum oxide power having an average grain diameter of 0.3mum or less is dispersed is arranged. The support board is moved in the horizontal direction by exerting fine load thereon, so that the surface of the dielectric body 3 is polished and the surface roughness is made to be about 0.2mum. A second electrode 4 is adhered to the dielectric body 3 and a third electrode 6 is superimposed on an insulator 5 such that an opening part thereof corresponds to an opening 7. The dielectric layer 3 has a uniform film thickness and an excellent plane, so that uniform ion generating quantity can be obtained. |
