Trimmer capacitor
AssigneeMurata Manufacturing Co., Ltd.
InventorsMasanori Oshima, Shuichi Taniguchi, Hiroyuki Watanabe
Life of this patent
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Abstract
A trimmer capacitor includes anchor portions that are arranged to be stepped down from the surface of a fixed electrode and are embedded in a stator near the upper surface of the stator at the tip portions of the fixed electrode. Because the tip portion of the fixed electrode has a section that is exactly perpendicular or nearly perpendicular to the surface of the fixed electrode in the region from the surface of the fixed electrode to the anchor portions, even if the upper surface of the stator is polished in the process for forming the stator, neither the area of the fixed electrode nor the capacitance changes.
Claims23
A trimmer capacitor comprising:
- a stator having an upper surface and a lower surface, and a substantially semicircular fixed electrode mounted on the upper surface of the stator;
- and
- anchor portions arranged so as to be stepped down from the surface of the fixed electrode and embedded in the vicinity of the upper surface of the stator at tip portions of the fixed electrode;
- a dielectric ceramic plate having an upper surface and a lower surface, and a movable electrode mounted on the upper surface of the dielectric ceramic plate;
- wherein the lower surface of the dielectric ceramic plate is in contact with the upper surface of the stator and a capacitance is generated between the fixed electrode and the movable electrode opposed to each other through the dielectric ceramic plate and is adjustable by rotating the dielectric ceramic plate on the stator and changing the area of the fixed electrode opposed to the movable electrode.
A method of manufacturing a stator comprising the steps of:
- forming a fixed electrode to include anchor portions and a lead out portion;
- forming a stator;
- embedding the fixed electrode in the stator;
- providing a dielectric ceramic plate with a movable electrode mounted thereon;
- mounting the dielectric ceramic plate on the stator;
- and
- rotating the dielectric ceramic plate on the stator and changing the area of the fixed electrode opposed to the movable electrode to adjust a capacitance generated between the fixed electrode and the movable electrode.
Dependencies are inferred from the claim text.