Electric capacitors, esp. thin film capacitors - having very thin dielectric films of silica, so overall dimensions of capacitor can be reduced

摘要

The capacitor consists of a substrate which carries electrode layers, and dielectric layers which are of SiO2. One pref. capacitor has a ceramic substrate coated with a silver electrode, followed by a dielectric layer of SiO2, then a second Ag electrode. Another pref. capacitor uses an Al foil coated on both sides with a layer of SiO2, and used with a similar coated Al foil in a capacitor winding. A third capacitor uses an Al foil covered with SiO2 and then a second electrode which is Al foil, metal obtd. by vapour deposition, or Ag. In all cases, the SiO2 is pref. obtd. via a soln. of an organic Si cpd. which is thermally decomposed. The organic Si cpd. is pref. in a solvent which is an ester, e.g. butyl- or amyl- acetate. The SiO2 has adequate mechanical strength and electric insulation even when only 0.1-1 mu m thick.