Abstract: A method of packaging for chip-on-board pressure sensor that includes a buffer layer with a coefficient of thermal expansion (CTE) intermediate between the transducer and a main chip-on-board substrate by which thermally induced package stresses can be greatly reduced or eliminated. Additionally, the use of a buffer layer with higher stiffness (elastic modulus) than the chip-on-board substrate further prevents or reduces flexural (bending) stresses from being transferred to the transducer. Such a buffer layer also enables a wider choice of materials for bonding and stable performance of pressure sensor in harsh media and environmental conditions. The pressure transducer can be adhesively bonded to a ceramic layer, which in turn can be adhesively bonded to an epoxy laminate chip-on-board substrate.

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 disposable pressure sensor system includes a disposable sensor assembly having at least one sensing element, carried on a housing or frame, and at least one electrical connector and/or mechanical connector for connecting the sensing element(s) to an external apparatus or device. The mechanical and/or electrical connectors are integrated in the housing or frame so that both the connector(s) and sensing element(s) are packaged in a single part. The assembly can be integrated in or attachable to a fluid carrying module, such as a dialysis cartridge, such that the sensing element(s) can sense the fluid in the module.

Abstract: A pressure sensor assembly configured for use with a catheter. In one illustrative embodiment, the pressure sensor assembly may include a multi-layer co-fired ceramic (MLCC) package. The MLCC package may include two or more ceramic layers that are co-fired together, with a cavity defined by at least some of the ceramic layers. At least one internal bond pad is provided within the cavity, and at least one external connection point is provided on the MLCC package exterior. A sensor, such as a pressure sensor, may be positioned and attached within the cavity. The sensor may be electrically connected to at least one of the internal bond pads. In some cases, a sealant may be used to encapsulate the sensor within the cavity. Once fabricated, the MLCC sensor assembly may be provided in a sensor lumen of a catheter.

Abstract: A method of packaging for chip-on-board pressure sensor that includes a buffer layer with a coefficient of thermal expansion (CTE) intermediate between the transducer and a main chip-on-board substrate by which thermally induced package stresses can be greatly reduced or eliminated. Additionally, the use of a buffer layer with higher stiffness (elastic modulus) than the chip-on-board substrate further prevents or reduces flexural (bending) stresses from being transferred to the transducer. Such a buffer layer also enables a wider choice of materials for bonding and stable performance of pressure sensor in harsh media and environmental conditions. The pressure transducer can be adhesively bonded to a ceramic layer, which in turn can be adhesively bonded to an epoxy laminate chip-on-board substrate.

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 method for direct die-to-die wire bonding incorporates a pressure sense die and a programmable compensation IC die that can be mounted on a ceramic substrate. The two die can be positioned beside each other such that wire bond pads on the pressure sense die and bonding leads on the compensation IC die are in same order. The pressure sense die and the compensation IC can be connected directly with wire bonds in order to reduce the number of wire bonds and to improve reliability. The pressure sense die can be designed with multiple wire bond pad patterns in order to be utilized with different programmable compensation IC dies.

Abstract: A method for direct die-to-die wire bonding incorporates a pressure sense die and a programmable compensation IC die that can be mounted on a ceramic substrate. The two die can be positioned beside each other such that wire bond pads on the pressure sense die and bonding leads on the compensation IC die are in same order. The pressure sense die and the compensation IC can be connected directly with wire bonds in order to reduce the number of wire bonds and to improve reliability. The pressure sense die can be designed with multiple wire bond pad patterns in order to be utilized with different programmable compensation IC dies.

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 method of packaging for chip-on-board pressure sensor that includes a buffer layer with a coefficient of thermal expansion (CTE) intermediate between the transducer and a main chip-on-board substrate by which thermally induced package stresses can be greatly reduced or eliminated. Additionally, the use of a buffer layer with higher stiffness (elastic modulus) than the chip-on-board substrate further prevents or reduces flexural (bending) stresses from being transferred to the transducer. Such a buffer layer also enables a wider choice of materials for bonding and stable performance of pressure sensor in harsh media and environmental conditions. The pressure transducer can be adhesively bonded to a ceramic layer, which in turn can be adhesively bonded to an epoxy laminate chip-on-board substrate.

Abstract: A pressure sensor apparatus and a method of forming the same. A substrate (e.g., PCB) can be provided that includes a top side and a bottom side. A pressure transducer can be directly bonded to the top side of the substrate, wherein the substrate comprises substrate walls forming a plated through-hole that allows for the passage of a sensed media to contact a back side of the pressure transducer. Thereafter, a metal carrier with an integral port is bonded to the bottom side of the substrate, thereby forming a chip-on-board pressure sensor in which the need for a plating or coating to allow adhesion between the pressure transducer and the metal carrier is eliminated. The pressure transducer may comprise, for example, silicon or silicon bonded to glass. The metal carrier can be provided with a feature that mates with a valve such as a Schrader valve.

Abstract: A catheter with a lumen containing a MLCC sensor assembly provides many advantages. The MLCC package can have a reference hole linking to a channel that is buried or on bottom layer of the package to provide venting or a reference input to a pressure sensor. A channel passing completely through the assembly can provide a path for reference air to a second sensor positioned further into the catheter. An ultraminiature assembly is designed to be capable of fitting inside a 6 French catheter with two lumen. One lumen is used for the sensor assembly, wires and reference pressure while a second can be used for other purposes such as a fluid fill lumen in Urology. The MLCC package allows forming connections to standard miniature pressure die using standard automated techniques such as wire bonding. Larger external connections on the MLCC package allow ease of connection to catheter wires or to micro-ribbon cables.

Abstract: A pressure sensor is constructed of a plastic package. The plastic package incorporates in the same material a sensing diaphragm including tensile and compression regions. Deposited on the diaphragm are metal electrodes and a polymer film having piezoresistive properties. The electrodes and/or the polymer film are directly printed onto the plastic package without the use of a mask.

Abstract: A sensor system for dialysis applications includes a plurality of pressure sensors, wherein each pressure sensor can be provided as an LC type sensor, and/or an RLC type sensor. Each sensor among the plurality of pressure sensors can be inductively coupled with a respective antenna among a plurality of antennas for the wireless transmission of pressure data. A dialysis machine is generally connected to the plurality of antennas, wherein the plurality of pressure sensors monitors pressure during operation of the dialysis machine to generate pressure data that is wirelessly transmitted to at least one antenna among the plurality of antennas.

Abstract: A wireless pressure sensor system has a pressure sensing capacitor and an inductor mounted on a common housing. The pressure sensing capacitor has a conductive diaphragm, a dielectric layer and a fixed electrode separated at least in part from the diaphragm by a gap formed in the housing. The electrode is arranged with a protrusion such that displacement of the diaphragm varies the area of capacitive contact with the electrode by rolling along the protrusion. The inductor coil and pressure sensing capacitor are connected to form a passive inductive-capacitive (LC) tank circuit. A remote interrogation circuit, inductively coupled to the pressure sensor inductor coil can be utilized to detect the resonant frequency of the LC tank which varies as a function of pressure sensed by the diaphragm.