Abstract: The present invention provides a pressure sensing device that includes at least one TMR sensor, and preferably an array of TMR sensors, with each TMR sensor having an insulating spacer layer interposed between a pinned and a free ferromagnetic layer. In an unbiased state, the magnetization vector of each of the ferromagnetic layers is preferably parallel to each other. Upon application of a small voltage, the magnetization vectors remain unchanged. Upon application of stress, the magnetization vector of the free magnetic layer will rotate, thus causing a corresponding and proportionally related change in the resistance of the sensor. This change in resistance can be sensed and used to calculate the stress applied thereto.

Abstract: An alternate method of designing and manufacturing a semiconductor pressure sensor inherently allows for significantly improved sensitivity, thereby allowing miniaturization of the sensor. As a result, the design lends itself to arranging the pressure sensors using this method in a two dimensional array, and measuring pressure distributions with very high lateral resolution. Furthermore, the design eliminates some of the processing complexities associated with the designs taught in the prior art, specifically those related to processes for manufacturing the plates of the parallel plate capacitor, or the piezoresistive strain elements. The invention allows the manufacture a two dimensional array of pressure sensors with very fine lateral resolution, which provides a much improved means over the prior art of recording fingerprints and the like.

Abstract: A sensor for identifying fingerprints or other skin textures includes an array of cells each including a membrane switch. Each switch includes a fixed lower electrode disposed on a chip substrate, and a flexible membrane disposed over the lower electrode and capable of flexing downward to establish electrical contact between the lower electrode and an upper electrode. The upper electrode can form the membrane itself or a layer of the membrane, or can be attached to other membrane layers. Switches situated underneath skin ridges change state (e.g. are closed) by the applied pressure, while switches underneath skin valleys remain in their quiescent state (e.g. open). Adjacent switch chambers are connected by fluid tunnels which allow the passage of air between the chambers. Each chamber is substantially closed to the exterior of the sensor, such that particles from the environment cannot contaminate the switch contact surface defined between the switch electrodes.

Abstract: The present invention provides a pressure sensing device that includes at least one GMR sensor, and preferably an array of GMR sensors, with each GMR sensor having a conducting spacer layer interposed between two ferromagnetic layers. In an unbiased state, the magnetization vector of each of the ferromagnetic layers is preferably parallel to each other. Upon application of a current, however, the magnetization vector of each ferromagnetic layer is changed, preferably to an antiparallel position, in which state the sensor is used to then sense stress applied thereto. Upon application of stress, the magnetization vectors of both free magnetic layers will rotate, thus causing a corresponding and proportionally related change in the resistance of the sensor. This change in resistance can be sensed and used to calculate the stress applied thereto.

Abstract: A fingerprint-sensing device with a sensor array that does not use active switching elements is fabricated on a base. Sensor support integrated circuits, which contain processing and addressing circuitry, are separately fabricated and subsequently mounted on the base, establishing electrical connections with an interconnect structure within the base, and are thus not integrated with the sensor array. The sensor support integrated circuits can be covered by a bezel structure and the sensor array by a covering material. In addition, a connection cable can be provided to connect the sensor array and the sensor support integrated circuits with a power source and to other external devices and to convey signals generated by the sensor array to the external devices.

Abstract: The present invention provides a pressure sensing device that includes at least one GMR sensor, and preferably an array of GMR sensors, with each GMR sensor having a conducting spacer layer interposed between two ferromagnetic layers. In an unbiased state, the magnetization vector of each of the ferromagnetic layers is preferably parallel to each other. Upon application of a current, however, the magnetization vector of each ferromagnetic layer is changed, preferably to an antiparallel position, in which state the sensor is used to then sense stress applied thereto. Upon application of stress, the magnetization vectors of both free magnetic layers will rotate, thus causing a corresponding and proportionally related change in the resistance of the sensor. This change in resistance can be sensed and used to calculate the stress applied thereto.

Abstract: A fingerprint-sensing device with a sensor array that does not use active switching elements is fabricated on a base. Sensor support integrated circuits, which contain processing and addressing circuitry, are separately fabricated and subsequently mounted on the base, establishing electrical connections with an interconnect structure within the base, and are thus not integrated with the sensor array. The sensor support integrated circuits can be covered by a bezel structure and the sensor array by a covering material. In addition, a connection cable can be provided to connect the sensor array and the sensor support integrated circuits with a power source and to other external devices and to convey signals generated by the sensor array to the external devices.

Abstract: A fingerprint-sensing device with a sensor array that does not use active switching elements is fabricated on a base. Sensor support integrated circuits, which contain processing and addressing circuitry, are separately fabricated and subsequently mounted on the base, establishing electrical connections with an interconnect structure within the base, and are thus not integrated with the sensor array. The sensor support integrated circuits can be covered by a bezel structure and the sensor array by a covering material. In addition, a connection cable can be provided to connect the sensor array and the sensor support integrated circuits with a power source and to other external devices and to convey signals generated by the sensor array to the external devices.

Abstract: A sensor for identifying fingerprints or other skin textures includes an array of cells each including a membrane switch. Each switch includes a fixed lower electrode disposed on a chip substrate, and a flexible membrane disposed over the lower electrode and capable of flexing downward to establish electrical contact between the lower electrode and an upper electrode. The upper electrode can form the membrane itself or a layer of the membrane, or can be attached to other membrane layers. Switches situated underneath skin ridges change state (e.g. are closed) by the applied pressure, while switches underneath skin valleys remain in their quiescent state (e.g. open). Adjacent switch chambers are connected by fluid tunnels which allow the passage of air between the chambers. Each chamber is substantially closed to the exterior of the sensor, such that particles from the environment cannot contaminate the switch contact surface defined between the switch electrodes.

Abstract: A slider of the type for use with a rotatable magnetic disk is disclosed. The slider has two ends and a bottom surface which includes an air bearing surface. An adhesive layer and continuous coating of carbon is located on the air bearing surface. A method of sputter depositing this continuous layer of carbon upon the air bearing surface of the slider is also provided. The continuous layer of carbon is crown-shaped and deposited using the sputtering technique. The carbon is directed from a source at the air bearing surface of a slider. A mask is placed between the source and slider so that the carbon is deposited in a crown shape. When the slider is viewed from front to rear the maximum depth of the coating is less than about 6 to 10 nm, while at the ends of the slider the coating depth is near 0 nm. The resistivity of the protective carbon layer is controlled for the additional benefit of protection from damages by electrostatic discharge.

Abstract: A slider of the type for use with a rotatable magnetic disk is disclosed. The slider has two ends and a bottom surface which includes an air bearing surface. An adhesive layer and continuous coating of carbon is located on the air bearing surface. A method of sputter depositing this continuous layer of carbon upon the air bearing surface of the slider is also provided. The continuous layer of carbon is crown-shaped and deposited using the sputtering technique. The carbon is directed from a source at the air bearing surface of a slider. A mask is placed between the source and slider so that the carbon is deposited in a crown shape. When the slider is viewed from front to rear the maximum depth of the coating is less than about 6 to 10 nm, while at the ends of the slider the coating depth is near 0 nm. The resistivity of the protective carbon layer is controlled for the additional benefit of protection from damages by electrostatic discharge.

Abstract: A slider of the type for use with a rotatable magnetic disk is disclosed. The slider has two ends and a bottom surface which includes an air bearing surface. An adhesive layer and continuous coating of carbon is located on the air bearing surface. A method of sputter depositing this continuous layer of carbon upon the air bearing surface of the slider is also provided. The continuous layer of carbon is crown-shaped and deposited using the sputtering technique. The carbon is directed from a source at the air bearing surface of a slider. A mask is placed between the source and slider so that the carbon is deposited in a crown shape. When the slider is viewed from front to rear the maximum depth of the coating is less than about 6 to 10 nm, while at the ends of the slider the coating depth is near 0 nm.