Abstract: A capacitive humidity sensor includes a semiconductor substrate, a protective layer and a humidity sensitive section including a pair of comb electrodes and a humidity sensitive layer having a dielectric constant, which changes in accordance with humidity. The comb electrodes are disposed on one surface of the semiconductor substrate through the protective layer to face each other with a predetermined gap. An interface between the protective layer and the humidity sensitive layer is planarized so that the sensor prevents a hysteresis in a variation of capacitance. For example, a surface of the protective layer can be made flat by polishing.

Abstract: A capacitance type humidity sensor includes: a detection substrate including a detection portion on a first side of the detection substrate; and a circuit board including a circuit portion. The detection portion detects humidity on the basis of capacitance change of the detection portion. The circuit portion processes the capacitance change as an electric signal. The detection substrate further includes a sensor pad on a second side of the detection substrate. The sensor pad is electrically connected to the detection portion through a conductor in a through hole of the detection substrate.

Abstract: A capacitance type physical quantity detector includes a sensor unit of which the capacitance varies depending upon a change in the physical quantity and a C-V converter unit which converts a change in the capacitance of said sensor unit into a voltage. The C-V converter unit includes an operational amplifier, a feedback capacitor, switching means connected in parallel with said feedback capacitor, a reference voltage-generating circuit for applying a reference voltage to the operational amplifier, and a drive voltage-generating circuit for applying a drive voltage to said sensor unit. At least any one of the feedback capacitance of said feedback capacitor, the reference voltage formed by said reference voltage-generating circuit or the drive voltage formed by said drive voltage-generating circuit varies depending upon the temperature to correct temperature characteristics of the sensor unit.

Abstract: A capacitance device includes a dielectric film, the first electrode and the second electrode. One of the two electrodes is divided into a plurality of electrode portions. Each of the divided electrode portions is connected with each other through switching transistors so that appropriate portions contributing to the capacitance can be selected. The device can vary its capacitance with high accuracy.

Abstract: The invention provides a humidity-sensitive element using, as a humidity-sensitive film, a polyimide having a molecular structure capable of forming a network structure at a high density, exhibiting less drift after being left standing at a high temperature and a high humidity and having excellent characteristics. A humidity-sensitive element according to the invention uses the polyimide obtained by dehydrating and ring closing a polyamide acid forming a network structure in which terminals of basic molecular chains are interconnected with one another, as a humidity-sensitive film. The humidity-sensitive element of the invention suitably uses a polyimide, in which terminals of basic molecular chains are interconnected with one another by use of triamine or a tricarboxylic acid, as a humidity sensitive film.

Abstract: In a sensor chip for a fluid flow sensor, a thin film portion is formed above a hollow cavity portion while leaving thin film layers formed on the surface of a substrate. A conductor is provided on the inner wall face of a through hole formed to penetrate the substrate to thereby electrically connect a detecting portion constituted by a conductor film in the thin film layers and a substrate conductor portion formed on the rear face side of the through hole. The surface of a circuit board is formed with a control circuit and a base conductor portion electrically connected to the control circuit. The sensor chip and the circuit board are layered and the substrate conductor portion and the base conductor portion are electrically connected.

Abstract: In a sensor chip for a fluid flow sensor, a thin film portion is formed above a hollow cavity portion while leaving thin film layers formed on the surface of a substrate. A conductor is provided on the inner wall face of a through hole formed to penetrate the substrate to thereby electrically connect a detecting portion constituted by a conductor film in the thin film layers and a substrate conductor portion formed on the rear face side of the through hole. The surface of a circuit board is formed with a control circuit and a base conductor portion electrically connected to the control circuit. The sensor chip and the circuit board are layered and the substrate conductor portion and the base conductor portion are electrically connected.

Abstract: An angular velocity sensor has a weight portion that can be drive-oscillated in a driving direction and be oscillated in a detecting direction when an angular velocity is applied, and unnecessary oscillation suppressing electrodes that can generate an electrostatic force to be applied to the weight portion in the detecting direction. The electrostatic force prevents the weight portion from being drive-oscillated in a direction other than the driving direction. As a result, unnecessary oscillation of the weight portion can be prevented even when the angular velocity sensor has a processing error.

Abstract: An angular velocity sensor has a weight portion that can be drive-oscillated in a driving direction and be oscillated in a detecting direction when an angular velocity is applied, and unnecessary oscillation suppressing electrodes that can generate an electrostatic force to be applied to the weight portion in the detecting direction. The electrostatic force prevents the weight portion from being drive-oscillated in a direction other than the driving direction. As a result, unnecessary oscillation of the weight portion can be prevented even when the angular velocity sensor has a processing error.