FLUIDIC SENSING ASSEMBLY WITH THERMAL PLATFORM

A sensor assembly may include an integrated circuit die. A sensor assembly may include an interconnect connected to the integrated circuit die. A sensor assembly may include an interposer mounted over and connected to the interconnect. A sensor assembly may include a sensor configured to transduce a property of one or more sample fluids, a thermal pathway between the sensor and the integrated circuit die, the thermal pathway extending through the interposer and the interconnect.

BACKGROUND

The present application relates to a sensor assembly used for fluidic sensing. Sensing a fluid to obtain information about the fluid is desirable in many circumstances. Sensing of biological fluids, such as blood, for various constituent materials of the biological fluids is often performed in a medical setting. A sensor assembly can be better designed for fluidic sensing to more conveniently and economically sense fluids.

SUMMARY

For purposes of summarizing the disclosure and the advantages achieved over the prior art, certain objects and advantages of the disclosure are described herein. Not all such objects or advantages may be achieved in any particular embodiment. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

All of these implementations are intended to be within the scope of the invention herein disclosed. These and other implementations will become readily apparent to those skilled in the art from the following detailed description of the preferred implementations having reference to the attached figures, the invention not being limited to any particular preferred implementations disclosed.

In one embodiments, the techniques described herein relate to a sensor assembly. The sensor assembly can comprise an integrated circuit die. The sensor assembly can comprise an interconnect connected to the integrated circuit die. The sensor assembly can comprise an interposer mounted over and connected to the interconnect. The sensor assembly can comprise a sensor configured to transduce a property of one or more sample fluids, a thermal pathway between the sensor and the integrated circuit die, the thermal pathway extending through the interposer and the interconnect.

In some embodiments, the sensor assembly can further include a heating element configured to heat the one or more sample fluids. In some embodiments, the sensor assembly can further include a thermal layer mounted to the interposer, wherein the sensor is disposed on the thermal layer. In some embodiments, the sensor assembly can further include a resist layer mounted to the interposer, wherein the sensor is disposed on the resist layer. In some embodiments, the resist layer electronically isolates the sensor and the interposer in use of the sensor assembly. In some embodiments, the resist layer is thermally conductive. In embodiments, the resist layer is a photoresist layer. In some embodiments, wherein the heating element is disposed between the interconnects and the integrated circuit die. In some embodiments, the heating element is disposed between the resist layer and the integrated circuit die. In some embodiments, the heating element is disposed in or on the interposer. In some embodiments, the heating element is disposed in or on the integrated circuit die. In some embodiments, the integrated circuit die does not contact a liquid during use of the sensor assembly. In some embodiments, the integrated circuit die includes silicon. In some embodiments, the integrated circuit die includes one or more amplifiers. In some embodiments, the integrated circuit die includes one or more converters. In some embodiments, the interconnect includes a plurality of copper pillars. In some embodiments, the interconnect is thermally conductive. In some embodiments, the interposer is electrically connected to the integrated circuit die through the interconnect. In some embodiments, the interposer is electrically connected to the integrated circuit die. In some embodiments, the interposer includes a via connected to the interconnect and a trace connected to the heating element. In some embodiments, the heating element includes a resistive heater. In some embodiments, the heating element includes a serpentine pattern. In some embodiments, the heating element has a resistance in a range of 80-120 ohm. In some embodiments, the thermal layer conducts heat between the sensor and the heating element in use of the sensor assembly. In some embodiments, the thermal layer electronically isolates the sensor and the interposer in use of the sensor assembly. In some embodiments, the thermal layer includes polyimide. In some embodiments, the thermal layer includes silicon nitride. In some embodiments, the sensor is electronically isolated from the interposer. In some embodiments, the sensor includes a gold pad. In some embodiments, the sensor includes a functionalized pad. In some embodiments, the sensor assembly can further include a plurality of electrodes disposed on the interposer over a plurality of vias through the interposer. In some embodiments, the sensor assembly can further include a plurality of electrodes disposed on the resist layer. In some embodiments, each of one or more of the plurality of electrodes on the interposer is disposed along an edge of the interposer. In some embodiments, the sensor assembly can further include an underfill layer positioned between the interposer and the integrated circuit die, and around the interconnect. In some embodiments, the sensor assembly can further include an electrical passivation layer disposed on at least the heating element to electrically passivate a local area. In some embodiments, the sensor assembly can further include one or more heater control pads disposed in or on the integrated circuit die, the one or more heater control pads configured to provide power to the heating element. In some embodiments, the sensor assembly can further include one or more electrode control pads disposed in or on the integrated circuit die, the one or more electrode control pads electrically connected to the plurality of electrodes on the resist layer. In some embodiments, the sensor is exposed to a fluid pathway through which the one or more sample fluids is to be delivered. In some embodiments, the sensor assembly can further include a plurality of integrated circuit dies, a plurality of interconnects attached to the plurality of integrated circuit die, a plurality of interposers mounted to the plurality of interconnects, a plurality of sensors configured to transduce a property of one or more sample fluids, and a plurality of heating elements configured to heat the one or more sample fluids through a corresponding plurality of interposers. In some embodiments, the sensor assembly can further include a stiffener to provide support to the sensor assembly. In some embodiments, the sensor assembly can further include a flow cell coupled to the plurality of integrated circuit dies and forming a fluid pathway on a first side of the plurality of integrated circuit dies. In some embodiments, the sensor assembly can further include a cooling block coupled to a second side of the plurality of integrated circuit dies, opposite to the first side of the plurality of integrated circuit dies, the cooling block configured to cool the sensor assembly in use. In embodiments, the cooling block is coupled to the plurality of integrated circuit dies through a thermally conductive adhesive. In some embodiments, the sensor assembly can further include a connector configured to electrically connect the plurality of integrated circuit dies to one or more external devices.

In another embodiments, the techniques described herein relate to a sensor assembly. The sensor assembly can comprise an integrated circuit die. The sensor assembly can comprise an interconnect connected to the integrated circuit die. The sensor assembly can comprise an interposer mounted over and connected to the interconnect. The sensor assembly can comprise a sensor configured to transduce a property of one or more sample fluids. The sensor assembly can comprise a heating element configured to heat the one or more sample fluids. The sensor assembly can comprise thermal pathway between the sensor and the heating element.

In some embodiments, the heating element is disposed in or on the interposer. In some embodiments, the heating element is disposed in or on the integrated circuit die.

In another embodiment, the techniques described herein relate to a sensor assembly. The sensor assembly can comprise an integrated circuit die. The sensor assembly can comprise an interconnect connected to the integrated circuit die. The sensor assembly can comprise an interposer mounted over and connected to the interconnect. The sensor assembly can comprise a heating element disposed in or on the interposer. The sensor assembly can comprise a sensor configured to transduce a property of one or more sample fluids. The sensor assembly can comprise a thermal pathway between the sensor and the heating element.

In some embodiments, the sensor assembly can include a resist layer mounted to the interposer, wherein the sensor is disposed on the resist layer. In some embodiments, the sensor assembly can include an electrical passivation layer disposed on the heating element.

In another embodiment, the techniques described herein relate to a sensor assembly. The sensor assembly can comprise an integrated circuit die forming a thermal platform. The sensor assembly can comprise one or more interconnects connected to the integrated circuit die. The sensor assembly can comprise an interposer mounted over and connected to the one or more interconnects. The sensor assembly can comprise a resist layer mounted over and connected to the interposer. The sensor assembly can comprise a reaction site disposed in or on the resist layer, the reaction site configured to transduce a property of one or more sample fluids. The sensor assembly can comprise a heating element disposed on the integrated circuit die, the heating element configured to heat the one or more sample fluids, wherein the interposer and at least one of the one or more interconnects form a thermal pathway between the reaction site and the heating element.

In some embodiments, the resist layer includes a thermal conductive layer including at least one of a polyimide or silicon nitride. In some embodiments, the resist layer includes photoresist. In some embodiments, the resist layer electrically isolates the reaction site and the interposer. In some embodiments, the integrated circuit die includes one or more amplifiers and one or more converters. In some embodiments the sensor assembly can further include a plurality of electrodes disposed on the interposer over a plurality of vias through the interpose, wherein the plurality of electrodes are coupled to at least one interconnect of the one or more interconnects, and wherein each of the plurality of electrodes are configured to transmit electrical signals received from the integrated circuit die through the at least one interconnect. In some embodiments the sensor assembly can further include one or more electrode control pads disposed in or on the integrated circuit die, the one or more electrode control pads electrically connected to the plurality of electrodes on the resist layer. In some embodiments the sensor assembly can further include an underfill layer positioned between the interposer and the integrated circuit die, the underfill layer filling a space around the one or more interconnects. In some embodiments the sensor assembly can further include an electrical passivation layer disposed on at least the heating element to electrically passivate a localized area. In some embodiments the sensor assembly can further include one or more heater control pads disposed in or on the integrated circuit die, the one or more heater control pads configured to provide power to the heating element. In some embodiments, the reaction site is exposed to a fluid pathway through which the one or more sample fluids is to be delivered.

In another embodiment, the techniques described herein relate to a fluidic sensor package. The fluidic sensor package can comprise a plurality of sensor assemblies, each sensor assembly of the plurality of sensor assemblies comprising: an integrated circuit die forming a thermal platform; one or more interconnects connected to the integrated circuit die; an interposer mounted connected to the one or more interconnects; a reaction site disposed on the interposer, the reaction site configured to transduce a property of one or more sample fluids; and a heating element disposed on the integrated circuit die, the heating element configured to heat the one or more sample fluids. The fluidic sensor package can comprise a flow cell coupled to the plurality of sensor assemblies and forming a fluid pathway for the one or more sample fluids on a first side of the plurality of sensor assemblies.

In some embodiments, the fluidic sensor package can further include a stiffener to provide support to the plurality of sensor assemblies. In some embodiments, the fluidic sensor package can further include a cooling block coupled to a second side of the plurality of sensor assemblies, opposite to the first side of the plurality of sensor assemblies, the cooling block configured to disperse heat from the plurality of sensor assemblies. In some embodiments, the cooling block is coupled to the plurality of sensor assemblies through a thermally conductive adhesive. In some embodiments, the fluidic sensor package can further include a connector configured to electrically connect the plurality of sensor assemblies to one or more external devices. In some embodiments, each sensor assembly of the plurality of sensor assemblies further comprises: a plurality of electrodes disposed on the interposer over a plurality of vias through the interposer, the plurality of electrodes coupled to at least one interconnect of the one or more interconnects, and at least a portion of the plurality of electrodes electrically coupled to at least a portion of the plurality of electrodes of another sensor assembly of the plurality of sensor assemblies and transmit electrical signals received from the integrated circuit die through the at least one interconnect. In some embodiments, each sensor assembly of the plurality of sensor assemblies further includes: one or more electrode control pads disposed in or on the integrated circuit die, the one or more electrode control pads electrically connected to the plurality of electrodes on the resist layer.

In another embodiment, the techniques described herein relate to an electronic assembly. The electronic assembly can comprise a sensor assembly comprising: a first integrated circuit die forming at least a first portion of a thermal platform; a first one or more interconnects connected to the first integrated circuit die; an interposer mounted over and connected to the first one or more interconnects; a reaction site disposed in or on the interposer, the reaction site configured to transduce a property of one or more sample fluids; and a heating element disposed on the first integrated circuit die, the heating element configured to heat the one or more sample fluids. The electronic assembly can comprise one or more electrical connections configured to receive control signals from an external device, the one or more electrical connections comprising: one or more electrical traces electrically coupled to the external device; a second integrated circuit die forming at least a second portion of the thermal platform; and a second one or more interconnects connected to the second integrated circuit die.

In some embodiments, the sensor assembly and the one or more electrical connections are electrically and physically connected via the thermal platform.

In another embodiment, the techniques described herein relate to a sensor assembly. The sensor assembly can comprise an integrated circuit. The sensor assembly can comprise one or more interconnects coupled to the integrated circuit. The sensor assembly can comprise a substrate mounted over and connected to the one or more interconnects, the substrate comprising: an interposer; a heating element disposed on the interposer; a photoresist layer mounted over and connected to the interposer; and a reaction pad disposed on the interposer above the heating element, the reaction pad configured to transduce a property of one or more sample fluids; wherein the heating element is configured to heat the one or more sample fluids.

In some embodiments, the sensor assembly can further include an electrical passivation layer disposed on the heating element, wherein the electrical passivation layer electrically isolates the reaction pad and the heating element. In some embodiments, the photoresist layer and the electrical passivation layer are thermally conductive, and the electrical passivation layer includes at least one of a polyimide or silicon nitride. In some embodiments, the photoresist layer and electrical passivation layer form a thermal pathway between the reaction pad and the heating element. In some embodiments, the integrated circuit includes one or more amplifiers and one or more converters. In some embodiments, the substrate is comprised of flexible material and the substrate further comprises: a plurality of electrodes disposed in the photoresist layer and electrically connected to a plurality of electrical connections disposed on the interposer over a plurality of vias through the interposer, the plurality of electrodes are electrically coupled to at least one interconnect of the one or more interconnects via the plurality of electrical connections, and each of the plurality of electrodes are configured to transmit electrical signals received from the integrated circuit through the at least one interconnect. In some embodiments, the substrate further includes an underfill layer coupled on one side of the interposer in contact with the integrated circuit, the underfill layer configured to receive the one or more interconnects. In some embodiments, the substrate further includes one or more heater control circuits disposed in or on the integrated circuit, the one or more heater control circuits configured to provide power to the heating element and to convert heat flow from the reaction pad into one or more electrical signals. In some embodiments, the reaction pad is exposed to a fluid pathway through which the one or more sample fluids is to be delivered.

In another embodiment, the techniques described herein relate to a fluidic sensor package. The fluidic sensor package can comprise a plurality of sensor assemblies, each sensor assembly of the plurality of sensor assemblies comprising: an integrated circuit; one or more interconnects coupled to the integrated circuit; and a substrate mounted over and connected to the one or more interconnects, the substrate including: a heating element configured to heat one or more sample fluids; a photoresist layer mounted over the heating element; and a reaction pad disposed on the photoresist layer above the heating element, the reaction pad configured to transduce a property of the one or more sample fluids. The fluidic sensor package can comprise a flow cell coupled to the plurality of sensor assemblies and forming a fluid pathway for the one or more sample fluids on a first side of the plurality of sensor assemblies.

In some embodiments, the fluidic sensor package can further include a stiffener to provide support to the plurality of sensor assemblies. In some embodiments, the fluidic sensor package can further include a cooling block coupled to a second side of the plurality of sensor assemblies, opposite to the first side of the plurality of sensor assemblies, the cooling block configured to disperse heat from the plurality of sensor assemblies. In some embodiments, the cooling block is coupled to the plurality of sensor assemblies through a thermally conductive adhesive. In some embodiments, the fluidic sensor package can further include a connector configured to electrically connect the plurality of sensor assemblies to one or more external devices.

In some embodiments, each sensor assembly of the plurality of sensor assemblies further comprises: a plurality of electrodes disposed in the photoresist layer and electrically connected to a plurality of electrical connections. In these embodiments, the plurality of electrodes can be electrically coupled to at least one interconnect of the one or more interconnects via the plurality of electrical connections. In these embodiments, each of the plurality of electrodes can be configured to transmit electrical signals received from the integrated circuit through the at least one interconnect. In these embodiments, at least a portion of the plurality of electrodes can be electrically coupled to at least a portion of the plurality of electrodes of another sensor assembly of the plurality of sensor assemblies and transmit electrical signals received from the integrated circuit through the at least one interconnect. In some embodiments, the fluidic sensor package can further include a connector configured to electrically connect the plurality of sensor assemblies to one or more external devices.

In another embodiment, the techniques described herein relate to an electronic assembly. The electronic assembly can comprise a sensor assembly comprising: a first integrated circuit; a first one or more interconnects coupled to the first integrated circuit; and a substrate mounted over and connected to the first one or more interconnects, the substrate including: an interposer; a heating element disposed on the interposer configured to heat one or more sample fluids; and a reaction pad disposed on the interposer above the heating element, the reaction pad configured to transduce a property of the one or more sample fluids. The electronic assembly can comprise one or more electrical connections configured to receive control signals from an external device, the one or more electrical connections comprising: one or more electrical traces electrically coupled to the external device; a second integrated circuit; and a second one or more interconnects connected to the second integrated circuit.

In some embodiments, the first integrated circuit and the second integrated circuit are electrically and physically coupled. In some embodiments, the substrate further includes an electrical passivation layer disposed on the heating element, wherein the electrical passivation layer electrically isolates the reaction pad and the heating element. In some embodiments, the substrate further includes a photoresist layer; and wherein the photoresist layer and the electrical passivation layer are thermally conductive. In some embodiments, the substrate further comprises: a plurality of electrodes disposed in the photoresist layer; and wherein the plurality of electrodes are electrically coupled to at least one interconnect of the first one or more interconnects, each of the plurality of electrodes are configured to transmit electrical signals received from the first integrated circuit through the at least one interconnect.

DETAILED DESCRIPTION

The present disclosure may be understood by reference to the following detailed description. It is noted that, for purposes of illustrative clarity, certain elements in various drawings may not be drawn to scale, may be represented schematically or conceptually, or otherwise may not correspond exactly to certain physical configurations of embodiments.

Generally described, one or more aspects of the present disclosure relate to a sensor assembly used for fluidic sensing. In certain embodiments, this disclosure relates to a sensor assembly having an interposer for fluidic sensing that can isolate a die from sample fluids. Conventional integrated circuits for sensing fluids have integrated circuit dies exposed to the liquids, and are therefore specially packaged with wires and conductors separated from the liquids. In various embodiments disclosed herein, an interposer can be used to separate an integrated circuit die from the liquids to improve packaging and to make manufacturing of integrated circuits used for fluidic sensing easier.

FIGS.1A-1Eillustrate an embodiment of a sensor assembly100according to this disclosure.FIG.1Ais an exploded view of the sensor assembly100.FIG.1Billustrates the assembled sensor assembly100, andFIGS.1C-1Eschematically show the assembled sensor assembly100in an electronic assembly with electrical connections130that can provide input/output connections for the sensor assembly100. As illustrated inFIGS.1A and1B, the sensor assembly100can include a thermal interposer102and a thermal platform104. In some embodiments, the thermal platform104can be a monolithic chip. In some embodiments, the thermal platform104can include and/or be formed from an integrated circuit chip or die. In some embodiments, the thermal platform104can include a heating element106(also referred to as a heater) and a plurality of heater control pads108(also referred to as control electrodes) connected to the heating element106. The heating element106can be resistive. The heating element106can be formed of any suitable materials, for example, nickel phosphorus (“NiP”), ruthenium (“Ru”), etc. In some embodiments, the heating element106can be positioned in a central area of the thermal platform104, proximate a top side of the thermal platform104. In some embodiments, the thermal platform104can further include an electrical passivation layer110disposed on the top side of the thermal platform104. The electrical passivation layer110can electrically passivate the local area. In some embodiments, the electrical passivation layer110can electrically isolate the heating element106and/or the heater control pads108on the thermal platform104from other components (e.g., interconnects120in the thermal interposer102). The electrical passivation layer110can be formed of a material that is electrically insulating to electrically passivate. In some embodiments, the electrical passivation layer110can be formed of a material that has a high thermal conductivity so as to convey heat from the heating element106. In some embodiments, the electrical passivation layer110can be formed of, for example, silicon nitride (“Si3N4”), polyimide, etc.

In accordance with various embodiments disclosed herein, the thermal interposer102can be disposed on top of the thermal platform104. In some embodiments, the thermal interposer102can include a fluidic interposer112(also referred to as a substrate) configured to separate a sample to be sensed on top of the sensor assembly100from other components of the sensor assembly100. The thermal interposer102can further include a resist layer114disposed on the fluidic interposer112. In some embodiments, a reaction site116can be disposed on the thermal interposer102. The reaction site116may be disposed on the resist layer114or directly on the fluidic interposer112. In some embodiments, the resist layer114can be a biocompatible and/or photoresist layer and may further define surface properties, geometric patterns, and other mechanical or biochemical properties to the sensor assembly100.

The thermal interposer102can further include an underfill118disposed between the fluidic interposer112and the thermal platform104. One or more interconnects120may be embedded in the underfill118and configured to thermally connect the thermal platform104and the thermal interposer102. In some embodiments, the interconnects120may be copper pillars having a copper body and solder cap. In some embodiments, the thermal interposer102can further include one or more conductive vias122disposed in the fluidic interposer112, thermally connecting the reaction site116to a bottom side of the fluidic interposer112. When the heating element106is connected to electrical power, heat can be generated and transmitted from the heating element106through the electrical passivation layer110, the interconnects120and vias122to the reaction site116. The reaction site116may be electrically isolated from the heating element106. As shown inFIGS.1A and1B, the heating element106, the interconnects120, the via122, and the reaction site116may have comparable diameters to enable efficient heat transfer between the components.

In some embodiments, the sensor assembly100can be connected to a set of electrical connections130through the thermal platform104as shown inFIGS.1C-1E. The electrical connections130can similarly include a thermal platform132having an integrated circuit, for example, a complementary metal-oxide-semiconductor application-specific integrated circuit (“CMOS ASIC”). In some embodiments, thermal platform132of the electrical connections130and thermal platform104of the sensor assembly100can be connected or form a single body. In some embodiments, the electrical connections130can further include interconnects134(e.g., copper pillars) embedded in an underfill136on top of the thermal platform132. In some embodiments, the electrical connections130can further include a flexible circuit substrate138with vias140and traces142on top of the interconnects134.

In some embodiments, the electrical connections130can further be connected to an external device, such as a package substrate (e.g., PCB) or another device (e.g., another die) by way of any suitable electrical connector, such as wire bonds, to the traces142. For example, the traces142may be electrically coupled to an external device such that the traces142can receive input signals for the electrical connections130and transmit output signals to the external device.

In some embodiments, control signals can be sent, for example, from an external device, to electrical connections130and then conveyed through the thermal platform132and/or thermal platform104and through the heater control pads108to the heating element106and/or the reaction site116on the resist layer114. In some embodiments, an electrical current can be transmitted through the sensor assembly100to the heating element106to generate heat, and the heating element106can pass the heat through the electrical passivation layer110, the interconnect120, the fluidic interposer112, the resist layer114, and/or the reaction site116to at least a portion of the sample fluids around the reaction site116. In some embodiments, the heating element106can pass the heat through only the resist layer114and the reaction site116to the at least a portion of the sample fluids. The generated heat can heat the portion of sample fluids such that the portion of sample fluids chemically, mechanically, or biologically reacts to achieve a desirable sensing condition. The integrated circuit die can then be configured to turn off the current to the heating element106and stop generating heat at the heating element106. When the heating element106stops providing heat to the reaction site116, the reaction site116can be configured to transduce and transfer temperature information (e.g. a change in temperature) to the thermal platform104through the fluidic interposer112and the one or more interconnects120.

FIGS.2A-2Eshow another embodiment of a sensor assembly200according to this disclosure.FIG.2Ais an exploded view of the sensor assembly200.FIG.2Bshows the assembled sensor assembly200, andFIGS.2C-2Eschematically show the assembled sensor assembly200in an electronic assembly with electrical connections230that can provide input/output connections for the sensor assembly200. Similar to the sensor assembly100ofFIGS.1A-1E, the sensor assembly200can include a thermal platform204and a thermal interposer202, but with additional electrodes217disposed on the thermal interposer202as shown inFIG.2A. The thermal platform204can include a monolithic chip205and an electrical passivation layer210disposed on the chip. The electrical passivation layer210can be, for example, a thin Si3N4 layer, or other suitable material. In some embodiments, a heating element206can be disposed beneath the electrical passivation layer210. The heating element206can be resistive. In some embodiments, the thermal platform204can include a plurality of electrodes, such as heater control pads208and electrode control pads209. In some embodiments, the heater control pads208can be configured to control the heating element206and disposed beneath the electrical passivation layer210. In some embodiments, the electrode control pads209configured to control electrodes217on top of the thermal interposer202and may not be covered by the electrical passivation layers210.

The thermal interposer202can similarly include a fluidic interposer212and a resist layer214on top of the fluidic interposer212. One or more reaction sites216or electrodes217can be disposed on top of the thermal interposer202, electrically or thermally connected to the thermal platform204through vias222or traces in the fluidic interposer212. In some embodiments, the thermal interposer202can further include an underfill218with one or more interconnects220(e.g., copper pillars) configured to electrically or thermally connect the one or more reaction sites216and/or electrodes217on top of the thermal interposer202to the heater control pads208and/or electrode control pads209in the thermal platform204. For example, as shown inFIG.2A, the sensor assembly200can include a central reaction site and four electrodes217. In some embodiments, the central reaction site can be configured to be thermally connected with the heating element206underneath the electrical passivation layer210as described above. In some embodiments, the electrodes217may be electrically connected to the electrode control pads209disposed on the thermal platform204. In some embodiments, the electrical connection between the electrodes217and the thermal platform204may be enabled by selectively exposing the one or more of the electrode control pads209through the passivation layer such that the one or more of the electrode control pads209are not electrically insulated from the components above. Electrical connection between the one or more reaction sites216or electrodes217and the thermal platform204can enable information transmission between the two.

In certain embodiments, each of the electrodes217may be positioned along an edge of the thermal interposer202such that another sensor assembly200according to this disclosure may be positioned next to the current one and be electrically connected through a set of electrical leads on electrodes217exposed on the edges of the thermal interposers202. In certain embodiments, electrodes217have an approximate “M” shape, as illustrated inFIGS.2A-2E, with the set of electrical leads positioned on the edge of the thermal interposer202. When more than one sensor assembly200is connected along the edges through the electrodes217, not all of the electrodes217on any individual sensor assembly200require a connection to the electrode control pads209on the thermal platform204. For example, only two neighboring electrodes217are electrically connected to the electrode control pads209on the thermal platform204in the configuration shown inFIG.2A. In some embodiments, a third electrode control pad209, as illustrated inFIG.2A, can also be electrically connected to the central reaction site216.

In some embodiments, the sensor assembly200can be connected to a set of electrical connections230through the thermal platform204as shown inFIGS.2C-2E. The electrical connections230can similarly include a thermal platform232having an integrated circuit, for example, a complementary metal-oxide-semiconductor application-specific integrated circuit (“CMOS ASIC”). In some embodiments, thermal platform232of the electrical connections230and thermal platform204of the sensor assembly200can be connected or form a single body. In some embodiments, the electrical connections230can further include interconnects234(e.g., copper pillars) embedded in an underfill236on top of the thermal platform232. In some embodiments, the electrical connections230can further include a flexible circuit238with vias240and traces242on top of the interconnects234.

In some embodiments, the electrical connections230can further be connected to an external device, such as a package substrate (e.g., PCB) or another device (e.g., another die) by way of any suitable electrical connector, such as wire bonds, to the traces242. For example, the traces242may be electrically coupled to an external device such that the traces242can receive input signals for the electrical connections230and transmit output signals to the external device.

In some embodiments, control signals can be sent, for example, from an external device, to electrical connections230and then conveyed through the thermal platform232and/or thermal platform204and through the heater control pads208to the heating element206and/or the reaction site216on the resist layer214. In some embodiments, control signals can be sent, for example, from an external device, to electrical connections230and then conveyed through the thermal platform232and/or thermal platform204and through the electrode control pads209to the electrodes217and into another sensor assembly200. Similarly, in some embodiments, control signals can be received by the sensor assembly200through the electrodes217, through the electrode control pads209, through the heater control pads208to the thermal platform204and/or the reaction sited216in the resist layer. As such, a control signal for the sensor assembly200may be received from an external device directly, or through an adjacent sensor assembly200.

In some embodiments, an electrical current can be transmitted through the sensor assembly200to the heating element206to generate heat, and the heating element206can pass the heat through the electrical passivation layer210, the interconnect220, the fluidic interposer212, the resist layer214, and/or the reaction site216to at least a portion of the sample fluids around the reaction site216. In some embodiments, the heating element106can pass the heat through only the resist layer214and the reaction site216to the at least a portion of the sample fluids. The generated heat can heat the portion of sample fluids such that the portion of sample fluids chemically, mechanically, or biologically reacts to achieve a desirable sensing condition. The integrated circuit die can then be configured to turn off the current to the heating element206and stop generating heat at the heating element206. When the heating element206stops providing heat to the reaction site216, the reaction site216can be configured to transduce and transfer temperature information (e.g. a change in temperature) to the thermal platform204through the fluidic interposer212and the one or more interconnects220.

FIGS.3A-3Eshow another embodiment of a sensor assembly300according to this disclosure.FIG.3Ais an exploded view of the sensor assembly300.FIG.3Bshows the assembled sensor assembly300andFIGS.3C-3Eschematically show the assembled sensor assembly300in an electronic assembly with electrical connections330that can provide input/output connections for the sensor assembly300. In some embodiments, the sensor assembly300can include an integrated circuit304(e.g., CMOS ASIC). In some embodiments, the integrated circuit304can be a monolithic chip. The integrated circuit304can include a plurality of electrical connection sites (e.g., aluminum pads) disposed on a top side of the integrated circuit304. The integrated circuit304can further include interconnects320(e.g., copper pillars) disposed on the plurality of electrical connection sites.

In certain embodiments, the sensor assembly300can further include a flexible circuit302(e.g., active flex) disposed on top of the integrated circuit304. The flexible circuit302can include a fluidic interposer312(e.g., a flexible substrate). The fluidic interposer312can include one or more heating elements306and associated electrical connections308coupled to the fluidic interposer312. For example, as shown inFIG.3A, the fluidic interposer312can include one resistive heating element306(e.g., Ru, Ni, etc.) sputtered or plated on the fluidic interposer312. In some embodiments, one or more of the electrical connections308can include electrodes on surfaces of the fluidic interposer312and vias/traces322through the fluidic interposer312. One or more of the electrical connections308can be connected to the heating element306to provide power and generate heat.

The electrical connections308can electrically and/or thermally connect to the interconnects320on the integrated circuit304. In some embodiments, the flexible circuit302can further include a bottom side resist layer318(e.g., underfill) coupled to a bottom side of the fluidic interposer312and configured to receive the interconnects320on the integrated circuit304, ensuring stable connection between the interconnects320on the integrated circuit304and the electrical connections308on the fluidic interposer312.

In accordance with various embodiments disclosure herein, an electrical passivation layer310(e.g., Si3N4) can be disposed at least on top of the heating element306to coat at least a top side of the heating element306and thereby electrically passivate the local area, whereas one or more of the one or more of the electrical connections308on the fluidic interposer312are exposed through the passivation layer310. A reaction pad316(e.g., gold pad) with a proper thickness can be sputtered on the electrical passivation layer310. In some embodiments, the reaction pad316and the rest of the sensor assembly300can be thermally connected to the heating element306and electrically isolated by the passivation layer310. The thickness of the reaction pad316can be further defined by electroplating process. In some embodiments, a photoresist layer314(e.g., biocompatible resist layer) can be added on top of the fluidic interposer312to further define the surface properties, geometric patterns, and other mechanical or biochemical properties of the sensor assembly300. The reaction pad316can be embedded in the photoresist layer314with top and bottom sides exposed.

In accordance with various embodiments, heat can flow both ways between the reaction pad316and the heating element306. In some embodiments, heat can flow between the reaction pad316and the heating element306through at least the electrical passivation layer310. The heating element306can include a control circuit309to convert the heat flow from the reaction pad316to one or more electrical signals (e.g., temperature signals). In some embodiments, signals can be sent through the interconnects320to the heating element306to generate heat which is transferred upward to the reaction pad316. In such embodiment, heat intentionally does not flow down through the interconnects320. In some embodiments, electrical signals from the control circuit309in the heating element306can be transmitted down to the integrated circuit304through the one or more electrical connections308on the fluidic interposer312and the interconnects320. Examples of control circuits309which can be included in the heating element306may be found in U.S. Patent Publication No. US20220126300, the entire contents of which are incorporated by reference herein in their entirety and for all purposes.

In some embodiments, the sensor assembly300can be connected to a set of electrical connections330through the integrated circuit304as shown inFIGS.3C-3E. The electrical connections330can similarly include a thermal platform332having an integrated circuit, for example, a complementary metal-oxide-semiconductor application-specific integrated circuit (“CMOS ASIC”). In some embodiments, thermal platform332of the electrical connections330and integrated circuit304of the sensor assembly300can be connected or form a single body. In some embodiments, the electrical connections330can further include interconnects334(e.g., copper pillars) embedded in an underfill336on top of the thermal platform332. In some embodiments, the electrical connections330can further include a flexible circuit338with vias340and traces342on top of the interconnects334.

In some embodiments, the electrical connections330can further be connected to an external device, such as a package substrate (e.g., PCB) or another device (e.g., another die) by way of any suitable electrical connector, such as wire bonds, to traces342. For example, the traces342may be electrically coupled to an external device such that the traces342can receive input signals for the electrical connections330and transmit output signals to the external device. In some embodiments, control signals and/or electrical current can be sent, for example, from an external device, to electrical connections330and then conveyed through the thermal platform332and/or integrated circuit304, through the interconnects320and into the control circuit309of the heating element306.

FIGS.4A-4Eshow another embodiment of a sensor assembly400according to this disclosure.FIG.4Ais an exploded view of the sensor assembly400.FIG.4Bshows the assembled sensor assembly400andFIGS.4C-4Eschematically show the assembled sensor assembly400in an electronic assembly with electrical connections430that can provide input/output connections for the sensor assembly400. The sensor assembly400can similarly include an integrated circuit404(e.g., CMOS ASIC) and a flexible circuit402(e.g., flex). In some embodiments, the integrated circuit404can include a plurality of interconnects420(e.g., copper pillars). The flexible circuit402can similarly include a fluidic interposer412and a plurality of electrical connections408connected to the interconnects420on the integrated circuit404. In some embodiments, the flexible circuit402can also include a bottom side resist418configured to receive the interconnects420, allowing stable connection between the electrical connections408on the fluidic interposer412and the interconnects420on the integrated circuit404. In some embodiments, the fluidic interposer412can include a heating element406with one or more of the electrical connections408providing power to the heating element406.

As described in more details above, with respect toFIGS.3A-3E, a passivation layer410can be disposed on top of the heating element406to coat at least a top side of the heating element406and thereby electrically passivate the local area. A reaction pad416can be sputtered on the passivation layer410. In some embodiments, the flexible circuit402can further include a photoresist layer414(e.g., biocompatible resist layer). The reaction pad416may be embedded in the photoresist layer414with top and bottom sides exposed. In some embodiments, the reaction pad416and the rest of the sensor assembly400can be thermally connected to the heating element406and electrically isolated by the passivation layer410. The thickness of the reaction pad416can be further defined by electroplating process. In some embodiments, the photoresist layer414can further define the surface properties, geometric patterns, and other mechanical or biochemical properties of the sensor assembly400. The reaction pad416can be embedded in the photoresist layer414with top and bottom sides exposed.

As described in more details above, with respect toFIGS.3A-3Eheat can flow both ways between the reaction pad416and the heating element406. In some embodiments, heat can flow between the reaction pad416and the heating element406through at least the electrical passivation layer410. The heating element406can include a control circuit409to convert the heat flow from the reaction pad416to one or more electrical signals (e.g., temperature signals). In some embodiments, signals can be sent through the interconnects420to the heating element406to generate heat which is transferred upward to the reaction pad416. In such embodiment, heat intentionally does not flow down through the interconnects420. In some embodiments, electrical signals from the control circuit409in the heating element406can be transmitted down to the integrated circuit404through the one or more electrical connections408on the fluidic interposer412and the interconnects420.

As shown inFIG.4A, the flexible circuit402can further include one or more additional reaction electrodes417embedded in the photoresist layer414, for example, four electrodes417. In certain embodiments, electrodes417have an approximate “M” shape, as illustrated inFIGS.4A-4E, with a set of electrical leads positioned on the edge of the flexible circuit402. In some embodiments, each of the electrodes417may be positioned along an edge of the flexible circuit402such that another sensor assembly400according to this disclosure may be positioned next to the current one and be electrically connected through the set of electrical leads on the electrodes417, as described above with respect toFIGS.2A-2E. In some embodiments, the electrodes417can be electrically connected to the integrated circuit404through the electric connections on the fluidic interposer412and the interconnects420on the integrated device to allow transmission of electrical and/or informational signals.

In some embodiments, the sensor assembly400can be connected to a set of electrical connections430through the integrated circuit404as shown inFIGS.4C-4E. The electrical connections430can similarly include a thermal platform432having an integrated circuit, for example, a complementary metal-oxide-semiconductor application-specific integrated circuit (“CMOS ASIC”). In some embodiments, thermal platform432of the electrical connections430and integrated circuit404of the sensor assembly400can be connected or form a single body. In some embodiments, the electrical connections430can further include interconnects434(e.g., copper pillars) embedded in an underfill436on top of the thermal platform432. In some embodiments, the electrical connections430can further include a flexible circuit438with vias440and traces442on top of the interconnects434.

In some embodiments, the electrical connections430can further be connected to an external device, such as a package substrate (e.g., PCB) or another device (e.g., another die) by way of any suitable electrical connector, such as wire bonds, to the traces442. For example, the traces442may be electrically coupled to an external device such that the traces442can receive input signals for the electrical connections430and transmit output signals to the external device.

In some embodiments, control signals and/or electrical current can be sent, for example, from an external device, to electrical connections430and then conveyed through the thermal platform432and/or integrated circuit404, through the interconnects420and into the control circuit409of the heating element406. As described in more detail inFIGS.2A-2E, control signals and/or electrical current may also be transmitted to adjacent sensor assemblies400from an external device via a connection path through the thermal platform432and/or integrated circuit404, interconnects420, and electrodes417. Similarly, control signals and/or electrical currents may be provided to the control circuit409of heating element406from an adjacent sensor assembly400, rather than the external device, via a connection path through the electrodes417, interconnects420, and integrated circuit404.

FIGS.5A-5Dshow another embodiment of a sensor assembly500according to this disclosure.FIG.5Ais an exploded view of sensor assembly500.FIG.5Billustrates a cross section of the sensor assembly500.FIG.5Cillustrates a top view of the sensor assembly500with a transparent thermal layer512.FIG.5Dillustrates an exploded view of the sensor assembly500with a transparent interposer502, such that vias510are visible.

As shown inFIGS.5A-5D, the sensor assembly500can include an interposer502and an integrated circuit die504configured to electrically connect to the interposer502. In some embodiments, the integrated circuit die504can comprise one or more converters and/or one or more amplifiers. In some embodiments, the interposer502and the integrated circuit die504can be electrically connected through one or more interconnects506. The one or more interconnects506can include copper pillars or other suitable conductive or semiconductive material.

In some embodiments, the interposer502can be a substrate. In some embodiments, the interposer502can be a flexible substrate, for example an insulating material (e.g., a polymer such as polyimide) with embedded conductive traces511and pads509. In some embodiments, the interposer502can be made of a dielectric material. The interposer502can include a heater508embedded in the interposer502. The heater508can be configured to generate thermal energy when electrical current is supplied. The heater508can comprise a resistive heater in various embodiments. In some embodiments, the heater508can have a serpentine pattern. In some embodiments, the heater508can have a resistance in a range of 50 ohm to 250 ohm, or in a range of 80 ohm to 120 ohm, e.g., about 100 ohm. The interposer502can also include one or more vias510to allow electrical and/or thermal connection between two opposite sides of the interposer502.

The sensor assembly500can further include a thermal layer512disposed on the interposer502. The sensor assembly500can further include a sensor514(e.g. a metal pad) disposed on the thermal layer512. The sensor514can be configured to be in contact with sample fluids and sense or measure properties of the sample fluids (e.g., temperatures, material properties, etc.). In some embodiments, the sensor514can comprise a functionalized electrode with a functionalizing material disposed on the pad. In some embodiments, the sensor514can be configured to be thermally coupled with and electrically isolated from the heater508of the interposer502. In some embodiments, the sensor514can be configured to be electrically isolated from the heater508of the interposer502. In some embodiments, the sensor514can be configured to be thermally coupled with and electrically isolated from the interposer502. In some embodiments, the sensor514comprises a gold pad.

In some embodiments, the thermal layer512can be made of a material with properties that are electrically and thermally insulating. However, the thickness of the thermal layer512can be provided to be sufficiently thin so as to conduct heat between the sensor514and the heater508or vias510. Heat generated by the heater508can be configured to heat at least a portion of the sample fluids to desired temperatures or for a desirable amount of time. In some embodiments, the heat can reach the portion of the sample fluids by passing through the thermal layer512.

The thermal layer512can have a composition and a thickness that electrically isolates or separates the sensor514(e.g., pad) from the heating element and vias510of the interposer502. In various embodiments, the thermal layer512can comprise a thermally and electrically insulating material that is nevertheless dimensioned to be thin enough to conduct heat vertically between the sensor514and the underlying vias510and heater508of the interposer502. In various embodiments, the thermal layer512can comprise a polymer (such as polyimide) provided on the interposer502by way of an adhesive. In other embodiments, an inorganic dielectric layer (such as silicon nitride) can be provided over the interposer502.

In various embodiments, when the sensor assembly500is in use, the heater508can be turned on to heat the sensor assembly500and/or at least a portion of fluids around the sensor514to desired temperatures. In some embodiments, the heater508can be turned on by supplying a current to the heater508, e.g., through the interconnects506, vias510, and traces511of the interposer502. The heater508can then be turned off to allow the sensor514to sense or measure information about the fluids (e.g., temperatures, etc.). For example, heat can flow from the fluid sample to the pad, through the thermal layer512to the vias510of the interposer502, and to the integrated circuit die504by way of the interconnects506. Sensed information (e.g., temperatures or changes in temperature) can be processed by the integrated circuit die504. In some embodiments, the sensed information from the sensor514can be transmitted to the integrated circuit die504through vias510, interconnects506, contact pads509, and/or solder bumps. The integrated circuit die504can then transmit sensed information, processed or unprocessed, through a connector to external devices.

For example, when the sensor assembly500shown inFIGS.5A-5Dis in use, the integrated circuit die504can be configured to transmit a current to the heating element by way of the interconnects506and vias510(and traces511and/or pads509connected to the vias510) to generate heat at the heating element. The heating element can pass the heat through the thermal layer512and the heater508to at least a portion of the sample fluids around the heater508. The generated heat can heat the portion of sample fluids such that the portion of sample fluids chemically, mechanically, or biologically reacts to achieve a desirable sensing condition. The integrated circuit die504can then be configured to turn off the current to the heater508and stop generating heat at the heater508. When the heater508stops providing heat, the sensor514can be configured to transduce and transfer temperature information (e.g. a change in temperature) to the integrated circuit die504through the interposer502and the interconnects506.

FIG.6shows another embodiment of a sensor assembly600according to this disclosure. The sensor assembly600can similarly include an interposer602and an integrated circuit die604electrically connected to the interposer602. The interposer602and the integrated circuit die604can be electrically connected by interconnects606(e.g., copper pillars). In some embodiments, the interposer602can include one or more vias608to electrically connect two opposite sides of the interposer602. The sensor assembly600can further include a sensor610configured to be in contact with sample fluids612and sense or measure information about the sample fluids612(e.g., temperatures, voltages, etc.).

The sensor assembly600can further include a heater614disposed in or on the integrated circuit die. The heater614can be configured to generate heat when a current is supplied. In some embodiments, the heater614can be disposed between one or more interconnects606and the integrated circuit die. In some embodiments, the heater614can be configured to heat at least a portion of sample fluids612by generating heat that passes through the interconnects606, the interposer602, and the sensor610.

The sensor assembly600shown inFIG.6can work similarly as described above to sense and transduce information with the sensor610and transmit that information to the integrated circuit die604for processing. For example, when the sensor assembly600shown inFIG.6is in use, the integrated circuit die604can be configured to turn on the heater614. The generated heat can pass through the one or more interconnects606and the interposer602to the sensor610and at least a portion of the sample fluids612around the sensor610. The generated heat can heat the portion of sample fluids612such that the portion of sample fluids612chemically, mechanically, or biologically reacts to achieve a desirable sensing condition. The heater614can then be turned off and stop generating heat. When heat is no longer provided to the sensor610, the sensor610can transduce and transfer temperature information (e.g. a change in temperature) to the integrated circuit die604through the interposer602and the interconnects606.

FIGS.7A-7Dillustrate an embodiment of a fluidic sensor package700that utilizes a plurality of sensor assemblies702.FIG.7Aillustrates a perspective view of the fluidic sensor package700,FIG.7Billustrates a cross section of the fluidic sensor package700,FIG.7Cis a top view of a flow cell710on the fluidic sensor package700, andFIG.7Dis a bottom view of the fluidic sensor package700. The plurality of sensor assemblies702may correspond to any of the embodiments of a sensor assembly as described herein, such as sensor assembly100, sensor assembly200, sensor assembly300, sensor assembly400, sensor assembly500, or sensor assembly600described above.

As shown inFIGS.7A-7D, the plurality of sensor assemblies702can be coupled to one another and implemented in the fluidic sensor package700. The fluidic sensor package700can include any desirable number of sensor assemblies702to achieve desirable results. In some embodiments, the fluidic sensor package700can have eight sensor chips703, each sensor chip having 384 sensor assemblies702.

The fluidic sensor package700can further include a stiffener704configured to provide a rigid structure to the fluidic sensor package700. Various electrical components706can be coupled to the stiffener704as needed. In some embodiments, a connector708can be coupled to the stiffener704and configured to transmit signals from the sensor assemblies702to external devices. The fluidic sensor package700can further include a flow cell710mounted to the stiffener704. In some embodiments, the flow cell710can be mounted to a first side of the stiffener704. The flow cell710can include fluid entry hole712aand fluid exit hole712bconfigured to allow one or more sample fluids to enter, flow through, and/or be maintained in the flow cell710. In some embodiments, the stiffener704can include a gasket716configured to seal the flow cell710such that fluid can only pass through the fluid entry hole712aand fluid exit hole712b.

A plurality of sensor assemblies702disclosed herein can be coupled to the stiffener704such that the sensors of the sensor chips703are exposed. Individual sensor assemblies702of the plurality thereof may include a fluidic interposer configured to separate a fluid inside the flow cell710and an integrated circuit or chip below the fluidic interposer. In some embodiments, the fluidic interposer can be a substrate. In some embodiments, the interposer can be a flexible substrate (e.g., polymide).

In some embodiments, the plurality of sensor chips703can be coupled to a second side of the stiffener704, opposite to the first side. The stiffener704can include an opening to allow the sensors of the sensor chips703to be exposed to contents of the flow cell710. In some embodiments, the plurality of sensor chips703can be coupled to the stiffener704at a first side of the sensor chip. The fluidic sensor package700can further include a cooling block714coupled to a second side of the plurality of sensor chips703, opposite to the first side of the plurality of sensor chips703. The cooling block714can be coupled to the plurality of sensor chips703through a thermal interface material715(e.g., thermal conductive adhesive). The cooling block714can be configured to provide a cooling effect to the fluidic sensor package700.

Reference throughout this specification to “some embodiments” or “an embodiment” means that a particular feature, structure, element, act, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in some embodiments” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment and may refer to one or more of the same or different embodiments. Furthermore, the particular features, structures, elements, acts, or characteristics may be combined in any suitable manner (including differently than shown or described) in other embodiments. Further, in various embodiments, features, structures, elements, acts, or characteristics can be combined, merged, rearranged, reordered, or left out altogether. Thus, no single feature, structure, element, act, or characteristic or group of features, structures, elements, acts, or characteristics is necessary or required for each embodiment. All possible combinations and subcombinations are intended to fall within the scope of this disclosure.

As used in this application, the terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list.

Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than are expressly recited in that claim. Rather, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment.

The foregoing description sets forth various example embodiments and other illustrative, but non-limiting, embodiments of the inventions disclosed herein. The description provides details regarding combinations, modes, and uses of the disclosed inventions. Other variations, combinations, modifications, equivalents, modes, uses, implementations, and/or applications of the disclosed features and aspects of the embodiments are also within the scope of this disclosure, including those that become apparent to those of skill in the art upon reading this specification. Additionally, certain objects and advantages of the inventions are described herein. It is to be understood that not necessarily all such objects or advantages may be achieved in any particular embodiment. Thus, for example, those skilled in the art will recognize that the inventions may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. Also, in any method or process disclosed herein, the acts or operations making up the method or process may be performed in any suitable sequence and are not necessarily limited to any particular disclosed sequence.