Texas Instruments Corporation

Burr-brown Corporation

Other

Motorola Corporation

Walter Baker Meinel

Kalin Valeriev Lazarov

Brian Goodlin

Vadim Valerievich Ivanov

Ricky A Jackson

Eric W Beach

R Mark Stitt, Ii

Rodney T Burt

Stephen James Sanchez

Karen Hildegard Ralston Kirmse

Shoubao Yan

Edward Mullins

Aden B Meinel

Eric L Hoyt

Philipp Steinmann

Jimmy R Naylor

Thomas A Somerville

Hubert John Biagi

Kandis Meinel

A MEMS IR sensor, with a cavity in a substrate underlapping an overlying layer and a temperature sensing component disposed in the overlying layer over the cavity, may be formed by forming an IR-absorbing sealing layer on the overlying layer so as to cover access holes to the cavity. The sealing layer is may include a photosensitive material, and the sealing layer may be patterned using a photolithographic process to form an IR-absorbing seal. Alternately, the sealing layer may be patterned using a mask and etch process to form the IR-absorbing seal.

Infrared sensor design using an epoxy film as an infrared absorption layer

A radiation sensor includes an integrated circuit radiation sensor chip (A) including first () and second () thermopile junctions connected in series to form a thermopile () within a dielectric stack (). The first thermopile junction () is insulated from a substrate () of the chip. A resistive heater () in the dielectric stack for heating the first thermopile junction is coupled to a calibration circuit () for calibrating responsivity of the thermopile (). The calibration circuit causes a current flow in the heater and multiplies the current by a resulting voltage across the heater to determine power dissipation. A resulting thermoelectric voltage (Vout) of the thermopile () is divided by the power to provide the responsivity of the sensor.

On-chip calibration system and method for infrared sensor

A radiation sensor () includes a radiation sensor chip () including first () and second () thermopile junctions connected to form a thermopile (). The first thermopile junction is disposed in a floating portion of a dielectric membrane () thermally insulated from a silicon substrate () of the chip, and the second thermopile junction is disposed in the dielectric membrane directly adjacent to the substrate. Bump conductors () are bonded to corresponding bonding pads (A) coupled to the thermopile () to physically and electrically connect the chip to conductors on a printed circuit board (). The silicon substrate transmits infrared radiation to the thermopile while blocking visible light.

Infrared sensor structure and method

With infrared (IR) sensors, repeatability and accuracy can become an issue when there are thermal gradients between the sensor and an underlying printed circuit board (PCB). Conventionally, a large thermal mass is included in the sensor packaging to reduce the effect from such thermal gradients, but this increase costs and size of the sensor. Here, however, a PCB is provided that includes an isothermal cage included therein that generally ensures that the temperature of the underlying PCB and sensor are about the same by including structural features (namely, the isothermal cage) that generally ensure that the thermal time constant for a path from a heat source to the thermopile (which is within the sensor) is approximately the same as thermal time constants for paths through the PCB.

Reducing thermal gradients to improve thermopile performance

A semiconductor device includes a semiconductor layer () and a dielectric stack () on the semiconductor layer. A plurality of etchant openings (-. . . ) are formed through the dielectric stack () for passage of etchant for etching a plurality of overlapping sub-cavities (-. . . ), respectively. The etchant is introduced through the etchant openings to etch a composite cavity () in the semiconductor layer by simultaneously etching the plurality of overlapping sub-cavities into the semiconductor layer.

Etching cavity structures in silicon under dielectric membrane

In conventional membrane infrared (IR) sensors, little to no attention has been paid toward transmissivity of IR near metal traces. Here, because the substrate of an integrated circuit carrying the sensor is used as a visible light filter, reflection of IR radiation back into the substrate can affect the operation and reliability of the IR sensor. As a result, an arrangement is provided that reduces the area occupied by metal lines by reducing the pitch and compacting the routing so as to reduce the effects from the reflection of IR radiation by metal traces.

Infrared light transmissivity for a membrane sensor

A MEMS device having a device cavity in a substrate has a cavity etch monitor proximate to the device cavity. An overlying layer including dielectric material is formed over the substrate. A monitor scale is formed in or on the overlying layer. Access holes are etched through the overlying layer and a cavity etch process forms the device cavity and a monitor cavity. The monitor scale is located over a lateral edge of the monitor cavity. The cavity etch monitor includes the monitor scale and monitor cavity, which allows visual measurement of a lateral width of the monitor cavity; the lateral dimensions of the monitor cavity being related to lateral dimensions of the device cavity.

Cavity process etch undercut monitor

A process of forming a MEMS device with a device cavity underlapping an overlying dielectric layer stack having an etchable sublayer over an etch-resistant lower portion, including: etching through at least the etchable sublayer of the overlying dielectric layer stack in an access hole to expose a lateral face of the etchable sublayer, covering exposed surfaces of the etchable sublayer by protective material, and subsequently performing a cavity etch. A cavity etch mask may cover the exposed surfaces of the etchable sublayer. Alternatively, protective sidewalls may be formed by an etchback process to cover the exposed surfaces of the etchable sublayer. Alternatively, the exposed lateral face of the etchable sublayer may be recessed by an isotropic etch, than isolated by a reflow operation which causes edges of an access hole etch mask to drop and cover the exposed lateral face of the etchable sublayer.

Cavity open process to improve undercut

An inertial sensor () includes a differential thermocouple () including first (A) and second (B) metal traces, a poly trace () with a first end connected to a first end of the first metal trace to form a first (&#x2212;) thermocouple junction and a second end connected to a first end of the second metal trace to form a second (+) thermocouple junction. A gas mass () located symmetrically with respect to the thermocouple junctions is heated by a heater (). Acceleration or tilting of the sensor shifts the relative location of the gas mass relative to the thermocouple junctions, causing differential heating thereof and generation of a corresponding thermocouple output signal.

Heated air mass WCSP package and method for accelerometer

Here, an apparatus is provided. The apparatus generally comprises a substrate and a thermopile. The thermopile includes a cavity that is etched into the substrate, a functional area that is formed over the substrate (where the cavity is generally coextensive with the functional area), and a metal ring formed over the substrate along the periphery of the functional area (where the metal ring is thermally coupled to the substrate).

Method and apparatus for reducing thermopile variations

There has been very little (if any) attention to address contamination diffusion within an integrated circuit (IC) because there are very few applications where a protective overcoat will be penetrated as part of the manufacturing process. Here, a sealing ring is provided that address this problem. Preferably, the sealing ring uses the combination of electrically conductive barrier rings and the tortuous migration path to allow an electronic device (i.e., thermopile), where a protective overcoat is penetrated during manufacture, to communicate with external devices while being isolated to prevent contamination.

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Tucson, AZ, United States of America

Walter Baker Meinel