| 摘要 |
PROBLEM TO BE SOLVED: To reduce the initial contact resistance value of a membrane switch and the increasing rate thereof with the elapse of time. SOLUTION: In this switch 100, flexible printed boards 1, 2 are formed by forming conductor layers 12, 22 consisting of Ag and containing a resin polymer as a binder on base films 11, 21, and printing and forming contact parts 13, 23 formed of an alloy particle by coprecipitation of Ag and Pd and containing a resin polymer as a binder thereon so as to cover the conductor layers 12, 22. The contact parts 13, 23 are arranged opposite to each other, and a spacer 3 is arranged between them. Thus, the contact parts 13, 23 are held with a prescribed space. The composition ratio of Ag in the alloy particle, the particle size of the alloy particle and the composition ratio of the alloy particle in the contact parts 13, 23 are set to 50-97 wt.%, 0.5-5.0 μm, and 91-95 wt.%, respectively, whereby the contact resistance of the contact parts 13, 23 can be minimized to realize a current carrying of about several hundreds mA. The corrosion resistance of the contact parts 13, 23 can be enhanced by including Pd, and the increasing ratio of contact resistance by the deterioration with the lapse of time can be reduced. |
