| 摘要 |
PURPOSE:To enhance the linearity between the ion density and the output by plating a mirror-surface electrode with silver, and by forming a sliver chloride layer on the outer surface layer part thereof. CONSTITUTION:A copper foil is applied over a substrate 1a made of an epoxy composite material, and is patterned by a lithography process or the like so as to form five pairs of copper electrodes 1b, each part of electrodes being oval copper pieces being separated and facing each other. The substrate 1 is set on a polisher for mirror-surface polishing the copper electrodes 1b. Then, the substrate is washed with water, and then moisture is blown off while it is degreased. Next, the surfaces of the electrode 1b are subjected to electrolytic glossy sliver plating so as to form a sliver plating layer 1c, and then, it is washed and dewatered. Further, terminal contact parts of the outer surfaces of the electrodes 1b are masked with a masking tape or the like, and a silver chloride layer 1b having a particle size of less than 1mum is formed on the outer surface of the sliver plating layer 1c in an electrolytic solution tank. Thereafter, the masking tape is removed. The layer 1c is coated thereover with epoxy resin so as to form an insulating film 1e. Thus formed sensor electrodes have a less surface roughness of the sliver chloride layer 1d, and accordingly, the linearity between the ion density and the output can be enhanced. |
