Abstract: The sensor geometry for improved package stress isolation is disclosed. A counterbore on the backing plate improves stress isolation properties of the sensor. The counterbore thins the wall of the backing plate maintaining the contact area with the package. The depth and diameter of the counterbore can be adjusted to find geometry for allowing the backing plate to absorb more package stresses. Thinning the wall of the backing plate make it less rigid and allows the backing plate to absorb more of the stresses produced at the interface with the package. The counterbore also keeps a large surface area at the bottom of the backing plate creating a strong bond with the package.

Abstract: The sensor geometry for improved package stress isolation is disclosed. A counterbore on the backing plate improves stress isolation properties of the sensor. The counterbore thins the wall of the backing plate maintaining the contact area with the package. The depth and diameter of the counterbore can be adjusted to find geometry for allowing the backing plate to absorb more package stresses. Thinning the wall of the backing plate make it less rigid and allows the backing plate to absorb more of the stresses produced at the interface with the package. The counterbore also keeps a large surface area at the bottom of the backing plate creating a strong bond with the package.

Abstract: The sensor geometry for improved package stress isolation is disclosed. A counterbore on the backing plate improves stress isolation properties of the sensor. The counterbore thins the wall of the backing plate maintaining the contact area with the package. The depth and diameter of the counterbore can be adjusted to find geometry for allowing the backing plate to absorb more package stresses. Thinning the wall of the backing plate make it less rigid and allows the backing plate to absorb more of the stresses produced at the interface with the package. The counterbore also keeps a large surface area at the bottom of the backing plate creating a strong bond with the package.

Abstract: The sensor geometry for improved package stress isolation is disclosed. A counterbore on the backing plate improves stress isolation properties of the sensor. The counterbore thins the wall of the backing plate maintaining the contact area with the package. The depth and diameter of the counterbore can be adjusted to find geometry for allowing the backing plate to absorb more package stresses. Thinning the wall of the backing plate make it less rigid and allows the backing plate to absorb more of the stresses produced at the interface with the package. The counterbore also keeps a large surface area at the bottom of the backing plate creating a strong bond with the package.

Abstract: A gauge pressure sensor apparatus and a method of forming the same. A constraint wafer can be partially etched to set the diaphragm size, followed by bonding to a top wafer. The thickness of the top wafer is either the desired diaphragm thickness or is thinned to the desired thickness after bonding. The bonding of top wafer and constraint wafer enables electrochemical etch stopping. This allows the media conduit to be etched through the back of the constraint wafer and an electrical signal produced when the etching reaches the diaphragm. The process prevents the diaphragm from being over-etched. The invention allows the die size to be smaller than die where the diaphragm size is set by etching from the back side.

Abstract: A semiconductor-based pressure sensor adapted for enhanced operation with controls electronics includes a pressure transducer having an output formed on a silicon die and an amplifier having an input and an output and fabricated on the silicon die next to the pressure transducer. The pressure transducer's output is provided to the amplifier's input via electrical connection. Output from the amplifier is connectable to a controller such as an ASIC.

Abstract: A gauge pressure sensor apparatus and a method of forming the same. A constraint wafer can be partially etched to set the diaphragm size, followed by bonding to a top wafer. The thickness of the top wafer is either the desired diaphragm thickness or is thinned to the desired thickness after bonding. The bonding of top wafer and constraint wafer enables electrochemical etch stopping. This allows the media conduit to be etched through the back of the constraint wafer and an electrical signal produced when the etching reaches the diaphragm. The process prevents the diaphragm from being over-etched. The invention allows the die size to be smaller than die where the diaphragm size is set by etching from the back side.

Abstract: A pressure sensor includes a sensing element fabricated on an N-type epitaxial layer grown on a P-type substrate, a P-type isolation region located around the edge of the sensing element die and in contact with the P-type substrate, and a conductive elastomeric seal engaging the P-type isolation region prevents shorting of the conductive elastomeric seal with the N-type epitaxial layer of the sensing element die. A method of making a pressure sensor comprises growing an n-type epitaxy layer on a p-type substrate wafer, resulting in a pressure sensor die and substrate having an edge, obtaining a mask adapted for fabricating an isolation diffusion layer around the edge using P-type material, and creating an isolation layer diffusion using P-type doping material around the edge using the mask. A conductive elastomeric seal can then be placed over the sensor die to make electrical contact to the package.

Abstract: A pressure sensor includes a sensing element fabricated on an N-type epitaxial layer grown on a P-type substrate, a P-type isolation region located around the edge of the sensing element die and in contact with the P-type substrate, and a conductive elastomeric seal engaging the P-type isolation region prevents shorting of the conductive elastomeric seal with the N-type epitaxial layer of the sensing element die. A method of making a pressure sensor comprises growing an n-type epitaxy layer on a p-type substrate wafer, resulting in a pressure sensor die and substrate having an edge, obtaining a mask adapted for fabricating an isolation diffusion layer around the edge using P-type material, and creating an isolation layer diffusion using P-type doping material around the edge using the mask. A conductive elastomeric seal can then be placed over the sensor die to make electrical contact to the package.

Abstract: A semiconductor-based pressure sensor adapted for enhanced operation with controls electronics includes a pressure transducer having an output formed on a silicon die and an amplifier having an input and an output and fabricated on the silicon die next to the pressure transducer. The pressure transducer's output is provided to the amplifier's input via electrical connection. Output from the amplifier is connectable to a controller such as an ASIC.

Abstract: A pressure sensor apparatus and method that incorporates a silicon frit bonded cap. The pressure sensor includes a silicon sensor wafer with diaphragms at a bottom surface thereof, a silicon cap wafer mounted on the topside of each sensor wafer, a plurality of silicon sensor die formed on the sensor wafer, a silicon cap wafer etched to create a plurality of reference cavities on the topside of the diaphragm, a thin glass frit to form a wafer-to-wafer bond between the sensor wafer and cap wafer. Sensing devices such as semiconductor die/sensor, peizoresistors, can be used to sense the pressure. The wafer-to-wafer frit bonding improves the output signal drift and the thermal performance of the pressure sensor minimizes the thermal mismatch created by anodic bonded glass wafers.

Abstract: A pressure sensor includes a silicon diaphragm having bottom and topside surfaces. The bottom surface has been formed using methods known to those skilled in the art. A first layer is formed and patterned on the topside surface of the diaphragm having an area larger than the diaphragm. A second layer is formed and patterned over the first layer, the second layer being larger in area than the first layer. Holes formed in the second layer are used to remove the first layer using methods known to those skilled in the art. A third layer is formed and patterned over the second layer. The third layer seals the holes in the second layer creating a sealed cavity with a reference pressure on the topside surface of the diaphragm. During operation, media is applied to the bottom surface of the diaphragm wherein the media pressure can be sensed by the pressure sensor in relation to the reference pressure sealed on the topside of the diaphragm.

Abstract: A pressure sensor is provided in which the pressure sensing components are isolated from a portion of an attached buffer member which is connected to a fluid conduit. The offset characteristic of the pressure sensor isolates stress from being transmitted between an attached external fluid conduit and the sensitive components of the pressure sensor. One embodiment of the pressure sensor solders a fluid conduit structure to a buffer member that is attached to a pressure sensor die. An alternative embodiment of the present invention avoids the need for making solder connections between the sensor structure and external components by utilizing elastomeric conductors and pressure seals in association with the pressure sensor composite structure and first and second housing structures. These elastomeric conductors also provide improved stress isolation. The housing structures are used to compress to the seal and the elastomeric conductor against selected portions of the composite sensor.