Freescale Semiconductor,inc.

Nxp Usa, Inc.

Peter T Jones

Chad S Dawson

William DeWitt McWhorter

Raimondo P Sessego

Bruno J Debeurre

Franklin P Myers

Jim D Pak

Seyed K Paransun

James D Stanley

David T Myers

Stephen Ryan Hooper

Paige M Holm

Mark Edward Schlarmann

Michael Naumann

Arvind S Salian

Kemiao Jia

Kevin R Fugate

Andres Barrilado

Larry Dale Metzler

Tripti Regmi

Carlos M Acuna

Mohammad A Faruque

Todd D Hoffmann

Chad Krueger

Rigoberto Lopez, Jr

Stephane Lestringuez

John Shipman

William D Mcwhorter

Seyed Parasun

Methods and apparatuses are provided for evaluating or testing stiction in Microelectromechanical Systems (MEMS) devices utilizing a mechanized shock pulse generation approach. In one embodiment, the method includes the step or process of loading a MEMS device, such as a multi-axis MEMS accelerometer, into a socket provided on a Device-Under-Test (DUT) board. After loading the MEMS device into the socket, a series of controlled shock pulses is generated and transmitted through the MEMS device utilizing a mechanized test apparatus. The mechanized test apparatus may, for example, repeatedly move the DUT board over a predefined motion path to generate the controlled shock pulses. In certain cases, transverse vibrations may also be directed through the tested MEMS device in conjunction with the shock pulses. An output of the MEMS device is then monitored to determine whether stiction of the MEMS device occurs during each of the series of controlled shock pulses.

Controlled pulse generation methods and apparatuses for evaluating stiction in microelectromechanical systems devices

Manufacturing of magnetometer units employs a test socket having a substantially rigid body with a cavity therein holding an untested unit in a predetermined position proximate electrical connection thereto, wherein one or more magnetic field sources fixed in the body provide known magnetic fields at the position so that the response of each unit is measured and compared to stored expected values. Based thereon, each unit can be calibrated or trimmed by feeding corrective electrical signals back to the unit through the test socket until the actual and expected responses match or the unit is discarded as uncorrectable. In a preferred embodiment, the magnetic field sources are substantially orthogonal coil pairs arranged so that their centerlines coincide at a common point within the predetermined position. Because the test-socket is especially rugged and compact, other functions (e.g., accelerometers) included in the unit can also be easily tested and trimmed.

Magnetometer test arrangement and method

Methods, systems and apparatus are provided to apply a magnetic pre-conditioning to magnetic tunneling junction (MTJ) sensors and other micro-magnetic devices after fabrication but before testing, trimming or other subsequent processing. The fabricated sensor device is passed through a magnetic field that has a known direction and orientation relative to the device so that the device is placed into a known state prior to final testing and trimming. Various embodiments allow the field to be applied in situ by a permanent magnet or electromagnet as the devices are being processed by a conventional device handler or similar processing system.

Magnetic pre-conditioning of magnetic sensors

A method for testing a plurality of pressure sensors on a device wafer includes placing a diaphragm of one of the pressure sensors on the device wafer in proximity to a nozzle of a test system. A pneumatic pressure stimulus is applied to the diaphragm via an outlet of the nozzle and a cavity pressure is measured within a cavity associated with the pressure sensor in response to application of the pneumatic pressure stimulus. The pneumatic pressure stimulus within the cavity corresponds to the pressure applied to the diaphragm. Methodology is executed to test the strength and/or stiffness of the diaphragm. Additionally, the methodology and test system can be utilized to determine an individual calibration factor for each pressure sensor on the device wafer.

Methodology and system for wafer-level testing of MEMS pressure sensors

A pressure sensor () includes a test cell () and sense cell (). The sense cell () includes an electrode () formed on a substrate () and a sense diaphragm () spaced apart from the electrode () to produce a sense cavity (). The test cell () includes an electrode () formed on the substrate () and a test diaphragm () spaced apart from the electrode () to produce a test cavity (). Both of the cells () are sensitive to pressure (). However, a critical dimension () of the sense diaphragm () is less than a critical dimension () of the test diaphragm () so that the test cell () has greater sensitivity () to pressure () than the sense cell (). Parameters () measured at the test cell () are utilized to estimate a sensitivity () of the sense cell ().

Pressure sensor having multiple pressure cells and sensitivity estimation methodology

Embodiments of systems for calibrating transducer-including devices include a board support structure, one or more motors, a motor control module, and a calibration control module. The board support structure holds a calibration board in a fixed position with respect to the board support structure. The motor(s) rotate the board support structure around one or more axes of a fixed coordinate system. The motor control module sends motor control signals to the motor(s) to cause the motor(s) to move the board support structure through a series of orientations with respect to the fixed coordinate system. The calibration control module sends, through a communication structure, signals to the transducer-including devices, which are loaded into a plurality of sockets of the calibration board. The signals cause the transducer-including devices to generate transducer data while the board support structure is in or moving toward each orientation of the series of orientations.

Methods and apparatus for calibrating transducer-including devices

Embodiments of packaged transducer-including devices and methods for their calibration are disclosed. Each device includes one or more transducers, an interface configured to facilitate communications with an external calibration controller, a memory, and a processing component. The external calibration controller sends calibration commands to the transducer-including devices through a communication structure. The processing component of each device executes code in response to receiving the calibration commands. Execution of the code includes generating transducer data from the one or more transducers, calculating calibration coefficients using the transducer data, and storing the calibration coefficients within the memory of the device.

Transducer-including devices, and methods and apparatus for their calibration

A MEMS pressure sensor () includes a sense cell (), a test cell (), and a seal structure (). The test cell includes a test cavity (), and the seal structure () is in communication with the test cavity, wherein the seal structure is configured to be breached to change an initial cavity pressure () within the test cavity () to ambient pressure (). Calibration methodology () entails obtaining () a test signal () from the test cell prior to breaching the seal structure, and obtaining () another test signal () after the seal structure is breached. The test signals are used to calculate a sensitivity () of the test cell, the calculated sensitivity is used to estimate the sensitivity () of the sense cell, and the estimated sensitivity () can be used to calibrate the sense cell.

Pressure sensor with built-in calibration capability

A test structure includes two capacitor structures, wherein one of the capacitor structures has conductor plates spaced apart by a cavity, and the other capacitor structure does not include a cavity. Methodology entails forming the test structure and a pressure sensor on the same substrate using the same fabrication process techniques. Methodology for estimating the sensitivity of the pressure sensor includes detecting capacitances for each of the two capacitor structures and determining a ratio of the capacitances. A critical dimension of the cavity in one of the capacitor structures is estimated using the ratio, and the sensitivity of the pressure sensor is estimated using the critical dimension.

Test structure and methodology for estimating sensitivity of pressure sensors

A tester configured to test a strip of devices is provided. The tester may include a communications system, a plurality of communication lines, a plurality of multiplexors, each multiplexor having at least two outputs, wherein each multiplexor is configured to receive a signal generated by the communications system via one of the plurality of communication lines, and each multiplexor may be selectably coupled to at least two of the devices in the strip of devices. The tester may be configured to index the plurality of communication lines to a first subset of the devices, initiate at least one test, command the devices to generate data for each of the at least one tests, retrieve data from a first set of the devices, and retrieve data from a second set of the devices.

Tester and method for testing a strip of devices

A mechanism for recovering from stiction-related events in a MEMS device through application of a force orthogonal to the stiction force is provided. A small force applied orthogonal to the vector of a stiction force can release the stuck proof mass easier than a force parallel to the vector of the stiction force. Example embodiments provide a vertical parallel plate or comb-fingered lateral actuator to apply the orthogonal force. Alternate embodiments provide a proof mass of a second transducer to impact a stuck MEMS actuator to release stiction.

Active lateral force stiction self-recovery for microelectromechanical systems devices

Manufacturing of magnetometer units (') employs a test socket () having a substantially rigid body () with a cavity () therein holding an untested unit () in a predetermined position () proximate electrical connection () thereto, wherein one or more magnetic field sources () fixed in the body () provide known magnetic fields at the position () so that the response of each unit () is measured and compared to stored expected values. Based thereon, each unit () can be calibrated or trimmed by feeding corrective electrical signals back to the unit () through the test socket () until the actual and expected responses match or the unit () is discarded as uncorrectable. In a preferred embodiment, the magnetic field sources () are substantially orthogonal coil pairs () arranged so that their centerlines (---) coincide at a common point () within the predetermined position (). Because the test-socket () is especially rugged and compact, other functions (e.g., accelerometers) included in the unit () can also be easily tested and trimmed.

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Scottsdale, AZ, United States of America

Peter T Jones