PURPOSE: To decrease the fluctuation in an oscillation frequency, by separating a capacitor into a fixed capacitor and a variable capacitor and covering the fixed capacitor only with a protective layer.
CONSTITUTION: An oscillator is constituted with a quartz oscillator 9, inverter 11, feedback resistor 26, and capacitors 24, 25. A capacitor 25 is separated with a fixed capacitor 25a and a variable capacitor 25b for trimming. The capacitors 24, 25a, 25b are formed by laminating conductor layers 19, 20, dielectric substance layer 21, and conductor layer 22 on a substrate 18 with wiring pattern connecting circuit elements. A protective layer 23 is formed at the uppermost part corresponding to an electrode 20a being one electrode, and since the adjustment of capacitance of the variable capacitor 25b is made by eliminating the conductor layer 22 in the notch of the protective layer 23, the capacitance change due to oxidation and corrosion of the trimming part is small.
KONNO TETSUO
YANAGI HIROFUMI
| JP54121750B | ||||
| JPS503672A | 1975-01-16 |