| 摘要 |
PURPOSE:To assure stable operation and a long life in an aq. soln. by forming the titled electrode in such a manner that the adhesiveness between a gate insulating film and ion non-sensitive film is maintained by an epoxy resin film. CONSTITUTION:This reference electrode consists of an FET element 2 which has a drain region 7b, a source region 7a and a channel region set by the gate insulating film 9 at one end, and is set with terminals 4, 5 of said source and drain regions at the other end. The ion non-sensitive film 10 is coated on the insulating film 9 and further the film 10 is coated and protected by a protective film 11 essentially consisting of the epoxy resin and having 0.1-1.0mm film thickness. The infiltration of water to the tight contact surface between the insulating film 9 and the non-sensitive film 10 is suppressed by the protective film 11 consisting of the water-resistant resin having the good adhesiveness with the film 10 and having the prescribed film thickness. The adhesiveness between the insulating film 9 and the non-sensitive film 10 is, therefore, maintained and the disconnection of the non-sensitive film 10 from the insulating film 9 in an aq. soln. to be measured is suppressed; in addition, the good response through the film 11 is obtd. |
