Fluid sensing system

A fluid sensing system includes a microfluidic chip, multiple sensors, and a communication device. The microfluidic chip includes at least one microfluidic channel extending a length through the microfluidic chip. The microfluidic chip is fluidly connected to a process fluid such that a fluid sample from the process fluid flows through the at least one microfluidic channel. The multiple sensors are operatively connected to the at least one microfluidic channel of the microfluidic chip. The multiple sensors are configured to monitor multiple different properties of the fluid sample within the at least one microfluidic channel. The communication device is operatively connected to the multiple sensors. The communication device is configured to receive data parameters representative of the multiple different properties of the fluid sample from the multiple sensors and wirelessly transmit the data parameters to a remote location.

BACKGROUND OF THE INVENTION

The subject matter herein relates generally to fluid sensing systems that monitor various properties of fluids in fluidic processes.

Fluid baths that are used in various fluidic processes, such as electroplating, often contain multiple chemical components. The performance of the fluidic processes is dependent on the type and concentration of the chemical components in the fluid bath, as well as other properties of the fluid bath such as temperature, conductivity (e.g., for electrolyte baths), and the like. For example, the concentrations of the components, the temperature, and the conductivity of an electroplating bath may affect a rate of plating on a target object as well as characteristics of the resulting coating, such as plating thickness. In order to maintain a level of consistency in the fluid process and resulting products, various properties of the fluid bath should be monitored over time.

A conventional process for monitoring one or more properties of a fluid bath is to remove a fluid sample from the bath and perform one or more tests on the fluid sample in a lab environment. In the lab, multiple different types of tests may be performed to measure different properties of the fluid. This conventional process is inefficient and costly. For example, the different properties of the fluid bath may be measured using labor-intensive analytical processes, such as titrating. Furthermore, the time required for transport of the fluid sample to the lab and the various testing apparatuses and the performance of the multiple analytical tests results in a relatively long lag time before obtaining an analysis result for the fluid bath. Due to the lag time, cost, and/or manual effort, the properties of the fluid bath may be monitored relatively infrequently, such as once an hour, once every few hours, or once a day. The infrequent monitoring presents a risk that one or more properties of the fluid bath may deviate from a designated operating range without timely detection, resulting in the production of non-conforming products that cannot be sold and/or must be recalled. Furthermore, the significant volume of the fluid sample required for the laboratory tests may also negatively affect the properties of the fluid bath when the sample is removed from the bath. Due to the extraction of the fluid samples, the volume of the fluid bath may decrease, requiring the addition of fresh fluid. The addition of the fresh fluid may increase material costs and may also undesirably modify component concentrations and other properties of the fluid bath.

A need remains for fluid sensing systems that provide frequent and efficient monitoring of multiple properties of fluids in fluidic processes for better control of the fluid bath and reduced cost.

BRIEF DESCRIPTION OF THE INVENTION

In an embodiment, a fluid sensing system is provided that includes a microfluidic chip, multiple sensors, and a communication device. The microfluidic chip includes at least one microfluidic channel extending a length through the microfluidic chip. The microfluidic chip is fluidly connected to a process fluid such that a fluid sample from the process fluid flows through the at least one microfluidic channel. The multiple sensors are operatively connected to the at least one microfluidic channel of the microfluidic chip. The multiple sensors are configured to monitor multiple different properties of the fluid sample within the at least one microfluidic channel. The communication device is operatively connected to the multiple sensors. The communication device is configured to receive data parameters representative of the multiple different properties of the fluid sample from the multiple sensors and wirelessly transmit the data parameters to a remote location.

In an embodiment, a fluid sensing system is provided that includes a microfluidic chip, multiple sensors, and a communication device. The microfluidic chip includes at least one microfluidic channel extending a length through the microfluidic chip. The microfluidic chip is fluidly connected to an electroplating bath such that a fluid sample from the electroplating bath flows through the at least one microfluidic channel. The multiple sensors are operatively connected to the at least one microfluidic channel of the microfluidic chip. The multiple sensors are configured to monitor multiple different properties of the fluid sample within the at least one microfluidic channel. The multiple sensors include at least two of an infrared sensor, a pH sensor, an electrochemistry sensor, an ultraviolet sensor, and an ultrasonic sensor. The communication device is operatively connected to the multiple sensors. The communication device is configured to receive data parameters representative of the multiple different properties of the fluid sample from the multiple sensors and wirelessly transmit the data parameters to a remote location.

In an embodiment, a fluid sensing system is provided that includes a microfluidic chip, multiple sensors, and a fluid input controller. The microfluidic chip includes at least one microfluidic channel extending a length through the microfluidic chip. The multiple sensors are mounted on the microfluidic chip and operatively connected to the at least one microfluidic channel to monitor multiple different properties of a fluid sample flowing through the at least one microfluidic channel. The fluid input controller is configured to control a flow of a first process fluid, a second process fluid, and a cleaning fluid one at a time into the at least one microfluidic channel of the microfluidic chip according to a designated protocol. The fluid input controller is configured to provide the first process fluid into the at least one microfluidic channel during a first time period, the cleaning fluid into the at least one microfluidic channel during a subsequent second time period, and the second process fluid into the at least one microfluidic channel during a subsequent third time period to monitor the different properties of both the first and second process fluids.

DETAILED DESCRIPTION OF THE INVENTION

One or more embodiments describe a fluid sensing system that integrates a microfluidic chip, multiple analytical sensors, and a wireless communication device for achieving continuous, accurate, and efficient monitoring of a fluidic process. The fluid sensing system may allow an operator to monitor the fluidic process using a mobile device, such that the operator may be at a remote location from the fluidic process and still able to monitor the process.

The microfluidic chip includes one or more microfluidic channels therethrough that receive a small sample amount of fluid (e.g., less than 10 mL or less than 1 mL) from a fluid bath of the fluidic process. The multiple analytical sensors are integrated with the microfluidic chip and positioned relative to the one or more microfluidic channels to measure different properties of the fluid sample within the channels. The fluid sample may flow through the one or more microfluidic channels such that the sensors provide continuous measurements of the corresponding properties of the fluid bath. In one or more embodiments, the multiple sensors may include a pH sensor for measuring the pH of the fluid, an infrared (IR) sensor for measuring the temperature of the fluid, an ultraviolet (UV) sensor for measuring the concentration of various components (e.g., additives) in the fluid, an electrochemistry module sensor for providing electrochemical analytical measurements, and/or the like. The communication device may transmit status signals, which include data parameters associated with one or more of the monitored properties of the fluid, to a remote location such as a server. Operators may be able to access the data parameters that are stored at the remote location via cloud computing and mobile data transfer to allow the operators to receive real-time updates regarding the conditions of the fluid bath on mobile devices.

One or more technical effects of the embodiments described herein include a cost savings due to avoiding the use of expensive conventional analytical instruments. Another technical effect is a reduction in the risk of human error via the use of an automated system. Yet another technical effect is the availability of real-time continuous monitoring of fluid conditions which allows for better control over the conditions and properties of the fluid. Still another technical effect is a reduced interference on the fluid bath by extracting only a very small sample amount of fluid into the microfluidic chip for analysis.

FIG. 1illustrates a monitoring system100according to an embodiment. The monitoring system100inFIG. 1includes a fluidic processing device102, a fluid sensing system104, a server106, and one or more operator input/output (I/O) devices108. The fluidic processing device102contains a process fluid (e.g., the process fluid110shown inFIG. 5) contained within a reservoir (e.g., the reservoir112shown inFIG. 5) of the device102. In an alternative embodiment, the process fluid may be contained within a network of tubes of the device102. The fluid sensing system104is fluidly connected to the process fluid and is configured to monitor multiple different properties of the process fluid using a microfluidic chip114and multiple different sensors116operatively connected to the microfluidic chip114. The fluid sensing system104is configured to transmit data parameters representative of the monitored properties of the process fluid to the server106. The server106stores the received data parameters. The operator I/O device108, which may be a personal computer, a laptop computer, a desktop computer, a tablet computer, a smartphone, a wearable computing device, or the like, may receive the data parameters from the server106and display the data parameters to an operator using a display of the I/O device108. The I/O device108may be located proximate to the server106or remote from the server106, and may communicate wirelessly with the server106. Therefore, an operator located remote from the fluidic processing device102may be able to monitor the conditions of the process fluid in real-time using the operator I/O device108. Although only one operator I/O device108is illustrated inFIG. 1, the server106may be configured to communicate, via a wired or wireless connection, with multiple operator I/O devices108.

In one embodiment, the fluidic processing device102is an electroplating apparatus102and the process fluid is an electrolyte bath contained within a reservoir of the electroplating apparatus102. Electroplating, as used herein, refers to electroplating and related processes, such as electroless plating, chemical etching, electro-polishing, and electrochemical etching processes. The electroplating apparatus102may be used to deposit copper or other metals such as tin, nickel, silver, gold, palladium, or the like, on a target object that is dipped into the electrolyte bath. The target object may be semiconductor wafers, connector strips, or the like. The electrolyte bath is composed of one or more dissolved metal salts as well as other ions that permit the flow of electricity. The electrolyte bath includes various components, such as solvents (e.g., water), electrolytes (e.g., salts, acids, and/or bases), and additives (e.g., chloride ions, corrosion inhibitors, levelers, suppressors, brighteners, accelerators, surfactants, and/or wetting agents). The types and concentrations of the various components within the electrolyte bath greatly influence the deposition of metal on the target object that is dipped into the bath. For example, electroplating quality and/or yield can be improved by strictly controlling the component concentrations and other properties (e.g., temperature, pH, conductivity, impedance, etc.) of the electrolyte bath within a corresponding narrow designated operating range, relative to allowing the component concentrations and/or the other properties of the bath to deviate from the designated operating range. In an alternative embodiment, the fluidic processing device102is not an electroplating apparatus. For example, the process fluid of the fluidic processing device102may be a waste water fluid, an automotive fluid (e.g., transmission fluid, engine oil, etc.), a washing machine fluid, or the like, instead of an electrolyte bath.

The microfluidic chip114of the fluid sensing system104is fluidly connected to the fluidic processing device102to receive fluid samples of the process fluid. For example, the microfluidic chip114may be fluidly connected to the fluidic processing device102via one or more carrier tubes (not shown) extending between the process fluid within the fluidic processing device102and the microfluidic chip114exterior of the fluidic processing device102. In an alternative embodiment, the microfluidic chip114may be mounted directly to the fluidic processing device102in direct contact with the process fluid within the reservoir of the device102. For example, the microfluidic chip114may be composed of one or more thermoplastic or glass materials that are resistant to acids or bases within the process fluid. The microfluidic chip114guides the fluid sample (of the process fluid) through one or more microfluidic channels120(shown inFIG. 2) of the chip114.

The multiple sensors116are operatively connected to the microfluidic chip114and are configured to measure different corresponding properties of the fluid sample within the one or more microfluidic channels120(FIG. 2) of the chip114. For example, the multiple sensors116may be structurally integrated with the microfluidic chip114, having one or more components (e.g., electrodes, conductive traces, mirrors, etc.) embedded within or mounted to the microfluidic chip114. In the illustrated embodiment, the microfluidic chip114is operatively connected to a pH sensor116A, a UV-VIS sensor116B, an IR sensor116C, and an electrochemistry module sensor116D. The pH sensor116A measures the pH of the fluid sample within the microfluidic chip114. The UV-VIS sensor116B measures the concentrations of various components of the fluid sample, such as brighteners, organic additives, and/or metallic ions. The IR sensor116C measures the temperature, and may also measure the concentration of some components of the fluid sample, such as organic additives. The electrochemistry module sensor116D measures electrical properties of the fluid sample, such as conductivity and impedance. Optionally, the electrochemistry module sensor116D may also measure pH and/or additive concentration within the fluid sample. The four types of sensors116A-D shown inFIG. 1are provided as example sensors and are not intended as an exclusive or exhaustive list of permitted sensors. In one or more alternative embodiments, the microfluidic chip114may be operatively connected to additional sensors other than the four illustrated sensors116A-D, less than all four sensors116A-D, and/or one or more different types of sensors other than the four sensors116A-D (e.g., an ultrasound sensor).

The sensors116generate data parameters that represent the corresponding monitored properties of the fluid sample of the process fluid. The data parameters are transmitted to the server106, which stores the data parameters on one or more non-transitory digital memories or storage devices (not shown). The data parameters may be transmitted from the sensors116to the server106via a wired connection over one or more conductive cables or via a wireless connection using radiofrequency (RF) signals. In an embodiment, the server106may be located at a remote location relative to the fluidic processing device102and the fluid sensing system104. For example, the server106may be located in a different room within the same building as the sensing system104, in separate building within the same geographical area (e.g., community, city, or state) as the sensing system104, or in a different geographical area than the sensing system104.

The operator I/O devices108may wirelessly communicate with the server106via a network connection (e.g., Internet, intranet, or the like) to receive the data parameters representative of the monitored properties of the process fluid. For example, the operator I/O devices108can access the monitored data parameters via cloud data transfer without being physically near the fluidic processing device102. As a result, the fluidic processing device102can be monitored by multiple operators at different locations. Furthermore, a single operator can access the monitored data parameters of multiple fluidic processing devices102via the network connection, which allows the operator to monitor the fluid properties of the multiple fluidic processing devices102without being present at the fluidic processing devices102.

FIG. 2is a schematic diagram of the fluid sensing system104according to an embodiment. The fluid sensing system104includes the microfluidic chip114, the multiple sensors116, a communication device122, one or more processors124, a digital memory126, and an audio-visual (AV) output device127. The one or more processors124are microprocessors, field programmable gate arrays, application specific integrated circuits, multi-core processors, or other electronic circuitry that carry out instructions of a computer program by carrying out arithmetic, logical, control, and/or input/output operations specified by the instructions. The memory126may be a computer hard disc, read only memory, random access memory, optical disc, removable drive, etc. The memory126may store the instructions that are used by the one or more processors124to perform the functions described herein. The one or more processors124, the memory126, and the AV output device127are optional and one or more of these components may be omitted from the fluid sensing system104in other embodiments.

The microfluidic chip114includes at least one microfluidic channel120extending a length through the chip114. In the illustrated embodiment, the at least one microfluidic channel120includes a primary (or first) channel130and multiple feeder channels132that are fluidly connected to the primary channel130. The microfluidic channels120have cross-sectional dimensions less than one millimeter, such as less than 0.5 mm. For example, the channels120may be generally circular and the diameter of the channels120is less than one millimeter. In another example, the channels120may have a height or width that is less than one millimeter. The primary channel130may have a length between 0.5 cm and 15 cm. The microfluidic channels120may have volumes that are less than 10 mL (e.g., 10 cm3), less than 5 mL, or less than 1 mL. The small size of the microfluidic channels120allows for extracting only small amounts of process fluid from the fluidic processing device102(shown inFIG. 1) for analysis, which reduces the interference of the analysis on the fluidic process performance relative to taking larger fluid samples.

The feeder channels132are each connected to a corresponding inlet port134, and the primary channel130is connected to an outlet port136. The fluid sample of the process fluid is received in the microfluidic channels120of the microfluidic chip114via one or more of the inlet ports134and exits the microfluidic chip114via the outlet port136. For example, the ports134,136may be secured to carrier tubes that extend between microfluidic chip114and the fluidic processing device102(shown inFIG. 1). The three feeder channels132converge into the primary channel130such that regardless of which inlet port134and feeder channel132receives the fluid sample, the fluid sample enters the primary channel130.

In the illustrated embodiment, multiple sensors116are arranged relative to the microfluidic chip114to measure different properties of the fluid sample within the primary channel130. There are four sensors116in the illustrated embodiment, but additional or fewer sensors may be used in other embodiments. The sensors116are illustrated in the schematic diagram as rectangular footprints representing the general locations of the sensors116or at least certain components thereof. The components that are located within the footprints may include microchips, electrodes, light emitters, detectors, mirrors, circuitry, and/or the like, depending on the specific sensors116. The multiple sensors116are spaced apart along the length of the primary channel130between the feeder channels132and the outlet port136, so the sensors116monitor the different corresponding properties of the fluid sample at different locations along the length of the primary channel130. As the fluid sample flows through the primary channel130towards the outlet port136, the sensors116measure different corresponding properties of the fluid sample at different times. For example, the first sensor116A measures a first property of the fluid sample, and then the second sensor116B measures a second property of the fluid sample. The third sensor116C subsequently measures a third property of the fluid sample, followed by the fourth sensor116D measuring a fourth property of the fluid sample. The properties of the fluid sample measured by the sensors116A-D may include pH, temperature, conductivity, impedance, component concentrations, and/or the like. In an embodiment, the sensors116A-D may measure the corresponding properties of the fluid sample continuously, meaning that the properties are measured frequently at rates of at least one measurement every five minutes, every two minutes, every one minute, every thirty seconds, one measurement every ten seconds, one measurement every second, or the like.

FIG. 3is a perspective view of the microfluidic chip114according to an embodiment. The microfluidic chip114inFIG. 3is the microfluidic chip114ofFIG. 2shown without the sensors116. The microfluidic chip114includes a substrate140and a cover142. The cover142is affixed to the substrate140, such as by bonding, to define the microfluidic chip114. The cover142and the substrate140may each be composed of one or more thermoplastic materials (e.g., polyethylene, polycarbonate, polymethyl methacrylate (PMMA), or the like) and/or one or more glass materials. Optionally, the cover142and the substrate140are composed of the same one or more thermoplastic and/or glass materials or are composed of different materials. In the illustrated embodiment, the microfluidic channels120are defined along an interface144between the substrate140and the cover142. For example, the channels120may be formed as grooves along a bottom surface146of the substrate140prior to affixing the bottom surface146to a top surface148of the cover142at the interface144. As used herein, relative or spatial terms such as “top,” “bottom,” “front,” “rear,” “upper,” and “lower” are only used to distinguish the referenced elements and do not necessarily require particular positions or orientations relative to the surrounding environment. Once the substrate140is affixed to the cover142, the top surface148of the cover142defines a floor of the microfluidic channels120. The substrate140may be bonded to the cover142such that the microfluidic channels120are sealed (e.g., hermetically sealed) along the interface144. Optionally, the microfluidic channels120may be defined as grooves along the top surface148of the cover142instead of, or in addition to, being defined in the substrate140.

The inlet and outlet ports134,136extend through a thickness of the substrate140and are open along a top surface150of the substrate140. The ports134,136may be formed through the substrate140by excising portions of the substrate material, such as via drilling. The sensors116, or components thereof, may be physically mounted to the cover142and/or to the substrate140to monitor the fluid sample within the microfluidic channels120. For example, although not shown, the cover142and/or the substrate140may include various electrodes and electrical circuitry embedded therein. The electrodes and circuitry may be components of specific sensors116and/or may be used to convey signals along the microfluidic chip114, such as from the sensors116to the communication device122. Some of the electrodes may be embedded along the top surface148of the cover142at the interface144and exposed along the primary channel130to contact the fluid sample within the primary channel130. Optionally, one or both of the substrate140and the cover142may be optically transparent or at least translucent, allowing light to penetrate through the respective material to interact with the fluid sample within the primary channel130before impinging on a detector that measures the effect of the fluid sample on the light.

Referring now back toFIG. 2, the multiple sensors116are operatively connected to the communication device122. The sensors116may be conductively connected to the communication device122via conductive signal paths along conductive traces, wires, cables, or the like. The communication device122may be disposed adjacent to the microfluidic chip114such that the sensors116on the chip114are connected to the communication device122via one or more electrical (or optical) wires or cables. In another embodiment, the communication device122may be mounted directly to the microfluidic chip114such that the sensors116are connected to the communication device122via conductive traces or other embedded circuitry of the microfluidic chip114. The sensors116may convey the data parameters representative of the corresponding measured properties of the fluid sample to the communication device122in the form of electrical signals. In an alternative embodiment, the communication device122is wirelessly connected to the sensors116and receives the data parameters wirelessly via RF signals.

The communication device122may include a wireless antenna152and associated circuitry and software to communicate wirelessly. The communication device122may include a transceiver or, alternatively, a receiver and a separate transmitter. Optionally, the antenna152and the associated circuitry of the communication device122may be at least partially embedded on the cover142and/or the substrate140(shown inFIG. 3) of the microfluidic chip114. The communication device122is used to wirelessly transmit status signals including updated measurements of one or more of the monitored properties of the fluid sample to a remote location, such as to the server106(shown inFIG. 1), one or more operator I/O devices108(FIG. 1), a central computer, or the like. The communication device122may transmit the status signals periodically at a designated time interval, such as every minute, every thirty seconds, every ten seconds, every second, or the like. Therefore, a recipient of status messages can receive timely information about the properties of the process fluid that is updated in real-time.

The one or more processors124are operatively connected to the tangible and non-transitory computer readable storage medium or memory126and are configured to perform operations based on instructions stored on the memory126. The one or more processors124are also operatively connected to the sensors116such that the processors124receive the data parameters measured by the sensors116. The data parameters may be received by the one or more processors124directly from the sensors116or indirectly via the communication device122. In one embodiment, the one or more processors124, the memory126, and the communication device122are commonly disposed within a housing. In another embodiment, the one or more processors124and the memory126are separate from the communication device122and not within a common housing. For example, the one or more processors124and the memory126may be disposed within the server106(shown inFIG. 1), a central computer, an operator I/O device108(FIG. 1), or the like. In another embodiment, the one or more processors124and/or the memory126are integrated into the microfluidic chip114. For example, the one or more processors124may be composed of circuitry that is at least partially embedded on the microfluidic chip114.

The one or more processors124are configured to analyze the data parameters generated by the sensors116. For example, the one or more processors124may compare the data parameters to designated threshold ranges for the different measured properties stored in the memory126to determine whether the data parameters are within the designated threshold ranges. The designated threshold ranges may be associated with the specific properties that are measured and the specific process fluid that is sampled. The designated threshold ranges represent conditions associated with desired performance of the fluidic process, leading to desired results. For example, in a certain electroplating process the designated threshold range for the temperature of the electrolyte bath may be between 60 and 70 degrees Celsius to provide a desired quality and/or amount of metal coating on the working electrode (that receives the coating). The designated threshold ranges vary for different fluidic processes and different desired results. The threshold ranges may be stored in a database on the memory126, which is accessed by the one or more processors124.

In one embodiment, the multiple inlet ports134are connected to different fluid sources. For example, a first inlet port134A may be fluidly connected to a first electrolyte bath160in one electroplating reservoir161, a second inlet port134B may be fluidly connected to a second electrolyte bath162in a different electroplating reservoir163, and a third inlet port134C may be fluidly connected to a cleaning fluid164in a storage container165. The cleaning fluid may be a solvent, such as de-ionized water, and optionally may include an additional substance such as a detergent, surfactant, alcohol, or the like. The microfluidic chip114is fluidly connected to the different fluid sources via tubing167.

The fluid sensing system104also includes fluid control elements, such as valves166, pumps168(e.g., syringe pumps), and the like, for controlling the selection and flow of the fluids from the different fluid sources to the microfluidic chip114. The valves166and pumps168are controlled by a fluid input controller170. The fluid input controller170includes one or more processors (e.g., microprocessors, field programmable gate arrays, application specific integrated circuits, multi-core processors) or other electronic circuitry that carry out instructions of a computer program by carrying out arithmetic, logical, control, and/or input/output operations specified by the instructions. For example, the fluid input controller170may operate according to a designated protocol to alternate the supply of fluid from the different electrolyte baths160,162and the cleaning fluid over time in order to provide continuous monitoring of both electrolyte baths160,162without contaminated readings. Although the fluid input controller170is shown inFIG. 3as a single electrical device that controls both the pumps168and the valves166, the fluid input controller170in an alternative embodiment may have one electrical device that controls the pumps168and a separate electrical device that controls the valves166.

Additional reference is made toFIG. 4, which is a graph400showing different fluids flowing through the microfluidic chip114(shown inFIG. 2) over time according to an embodiment. The graph400may represent a sequence at which the fluid input controller170supplies the different fluids160,162,164to the microfluidic chip114over time according to a designated protocol. The vertical axis402shows three different fluid sources including the first electrolyte bath160(“Bath A”), the second electrolyte bath162(“Bath B”), and the cleaning fluid164(“Cleaning Fluid”). The horizontal axis404shows seven time periods. Each of the time periods may, but need not, represent the same amount of time as the other time periods. Although seven time periods are shown, the sequence may be repeated for longer than the illustrated seven periods. In the illustrated embodiment, during the first time period, a fluid sample from the first electrolyte bath160(e.g., bath A) is flowed through the microfluidic chip114in order to monitor multiple properties of the first electrolyte bath160. For example, the fluid input controller170may control the valve166and pump168between the first electrolyte bath160and the microfluidic chip114to allow a fluid sample from the bath160to flow into the microfluidic chip114through the first inlet port134A, while blocking the flow of the other fluids162,164into the microfluidic chip114. As a result, the sensors116on the microfluidic chip114monitor multiple properties of the first electrolyte bath160during the first time period.

During the second time period, no more fluid from the first electrolyte bath160flows through the microfluidic chip114. Instead, the fluid input controller170directs the cleaning fluid164into the microfluidic chip114through the inlet port134C. The cleaning fluid164rinses out the primary channel130of the microfluidic chip114and any electrodes or other components of the sensors116exposed to the channel130to remove residual amounts of the fluid160. During the subsequent third time period, the fluid input controller170directs a fluid sample from the second electrolyte bath162(e.g., bath B) into the microfluidic chip114through the inlet port134B, while the flow of the other two fluids160and164is blocked. The sensors116on the microfluidic chip114monitor multiple properties of the second electrolyte bath162during the third time period. Afterwards, the cleaning fluid164is again flowed through the channels132,120of the microfluidic chip114during the fourth time period to rinse out and remove the residual amounts of the fluid162. The sequence may repeat, such that another fluid sample from the first electrolyte bath160is flowed through the microfluidic chip114during the fifth time period, the cleaning fluid164is flowed through the chip114during the sixth time period, and another fluid sample from the second electrolyte bath162is flowed through the microfluidic chip114during the seventh time period.

In the sequence shown inFIG. 4, the properties of each of the first and second electrolyte baths160,162are monitored by the microfluidic chip114once every four time periods. The time periods may have a length of seconds. For example, if the time periods have ten second durations, then there is only thirty seconds of a lag between successive measurements of each of the first and second electrolyte baths160,162(because three time periods separate each successive measurement). Therefore, the fluid sensing system104may be configured to monitor fluid samples from multiple different fluidic processes by alternating the source of the fluid samples that flow through the microfluidic chip114.

In another embodiment, instead of or in addition to monitoring fluid samples from different fluidic processes, the fluid sensing system104may monitor fluid samples from multiple different locations within a single fluidic process. For example, the first inlet port134A may receive a fluid sample extracted from a first region of an electrolyte bath and the second inlet port134B may receive a fluid sample extracted from a second region of the same electrolyte bath. In this embodiment, Bath A on the vertical axis402of the sequencing graph400would represent the first region of the electrolyte bath, and Bath B on the vertical axis402would represent the second region of the same electrolyte bath. It is recognized that the microfluidic chip114is not limited to monitoring fluid properties of electrolyte baths, but can also monitor the fluid properties in other fluidic processes. For example, the first inlet port134A and the second inlet port134B may receive alternating fluid samples extracted from a first tube of a closed network of tubes and a second tube of the closed network of tubes.

The fluid sample that flows from the channel130through the outlet port136may be conveyed through one or more carrier tubes (not shown) back to the source of the fluid sample to recycle the fluid. By performing the analysis of the process fluid on a small sample size of fluid that is recycled back into the process fluid, the interference on the fluidic process that is caused by the monitoring and analysis of the fluid sample may be negligible, or at least significantly less than other systems that extract larger amounts of fluid for testing in multiple instruments.

In an embodiment, the one or more processors124are operatively connected to the AV output device127. The AV output device127may be a display device, an audio speaker, a vibration device, or a combination thereof. For example, the AV output device127may be a smartphone, a tablet computer, a laptop computer, a desktop computer, or the like. Optionally, the AV output device127may be the operator I/O device108shown inFIG. 1. In one embodiment, the one or more processors124are connected to the AV output device127via a wired connection. For example, the one or more processors124, the memory126, and the AV output device127may represent or be contained within a common computing device, such as a smartphone, a tablet computer, a workstation, or the like. In an alternative embodiment, the one or more processors124and the memory126are remote from the AV output device127, and the processors124communicate wirelessly with the AV output device127via the communication device122. For example, the processors124may generate a signal that is transmitted from the communication device122to the AV output device127that is carried by or proximate to an operator.

In an embodiment, responsive to the one or more processors124determining that one or more of the measured properties of the process fluid are outside of the designated threshold range(s), the one or more processors124control the AV output device127to generate an alert. The alert may be an audio alarm emitted by a speaker of the device127, a visual alert presented on a display of the device127, a vibrational alert generated by a vibration device of the device127, and/or the like. The one or more processors124generate an electrical signal that controls the type of alert provided by the AV output device127. The alert may also provide information to notify an operator which of the measured properties are outside of the designated threshold range, a degree or extent that such properties are outside of the designated threshold range, suggested or automatically undertaken remedial actions to bring such properties back within the designated threshold range, or the like. For example, the information may be provided by the AV output device127in a text-based visual message and/or a voice-based audio message. Since the AV output device127may be the I/O device108shown inFIG. 1, the fluid sensing system104can provide the alerts remotely to operators that are not in the immediate vicinity of the fluidic process. An operator that is in another room or even in another building can receive a notification immediately after the processors124determine that one or more of the properties of the process fluid deviate from the designated threshold range. As a result, the operator is able to take corrective actions in a timely fashion, which can reduce the negative effect of the deviating properties on the fluidic process. The one or more processors124optionally may be operatively connected to one or more control devices proximate to the fluidic processing device102to provide automatic remedial modifications to the process fluid based on the monitored properties of the fluid sample of the process fluid. For example,FIG. 5illustrates the fluidic processing device102and a component addition system200according to an embodiment. The fluidic processing device102includes a reservoir112that contains the process fluid110therein. As described above, the process fluid110may be, but is not limited to, an electrolyte bath for electroplating or a similar process. The component addition system200includes at least one component receptacle202that contains an amount of an ingredient or reagent of the process fluid110, such as a solvent, an acid, a base, a salt, a metal component, an additive, a mixture or solution of multiple components, or the like. Three component receptacles202A,202B,202C are shown in the illustrated embodiment, and each receptacle202A-C contains a different component. The component receptacles202A-C are fluidly connected, via tubing, to a valve system204that includes one or more valves for regulating and controlling the flow of the components from the receptacles202to the process fluid110in the reservoir112.

The valve system204is operatively connected to a valve controller206that controls the operations of the valve system204. The valve controller206includes one or more processors (e.g., microprocessors, field programmable gate arrays, application specific integrated circuits, multi-core processors) or other electronic circuitry that carry out instructions of a computer program by carrying out arithmetic, logical, control, and/or input/output operations specified by the instructions. The valve controller206may generate and transmit control signals to the valve system204to control the flow of the components from the receptacles202to the process fluid110. The valve controller206can control the time at which each of the components is added to the process fluid110, as well as the amount and flow rate of the component. When the fluidic processing device102is operating at normal, desired conditions, the valve controller206may control the valve system204to close all valves, preventing the flow of the components from the receptacles202into the process fluid110. Although the valve system204and the valve controller206are shown inFIG. 5, the component addition system200may include other fluid control elements, such as one or more pumps, to assist in controlling the flow of the components into the reservoir112.

In an example, the first component receptacle202A contains a basic component, and the second component receptacle202B contains an acidic component. In response to the one or more processors124determining, based on the monitored properties of the sample fluid in the microfluidic chip114(shown inFIG. 2), that the pH of the process fluid110is too acidic relative to a designated threshold pH range for the process, the one or more processors124communicate a signal to the valve controller206. In response to receiving the signal, the valve controller206may automatically control the valve system204to supply the basic component from the receptacle202A into the reservoir112to raise the pH of the process fluid110. The amount of basic component that is added is controlled such that the resulting pH of the process fluid110is within the designated threshold range. The acidic component within the second receptacle202B is not added into the reservoir112since the process fluid110is already too acidic. Therefore, the fluid sensing system104(shown inFIG. 2) may also include the component addition system200shown inFIG. 5to allow for automatic remedial action without the need for operator intervention.

Alternatively, or in addition, the addition system200may include a heating element (not shown) in contact with the process fluid110. In response to determining that the temperature of the process fluid110is below the designated threshold range for the specific process, the one or more processors124may automatically activate the heating element (or increase the heat output of an active heating element) to increase the temperature of the process fluid110without the need for operator intervention.

FIG. 6is a schematic diagram of the microfluidic chip114and the multiple sensors116of the fluid sensing system104according to an alternative embodiment. The microfluidic chip114shown inFIG. 6differs from the microfluidic chip114shown inFIG. 2in the number and layout of the microfluidic channels120. The microfluidic chip114in the illustrated embodiment includes a single inlet port134and a single feeder channel132. The single feed channel132splits into four primary channels130. The four primary channels130extend parallel to one another along respective lengths of the channels130. The microfluidic chip114includes four outlet ports136located at the ends of the primary channels130. The fluid sample may enter the microfluidic chip114through the inlet port134and flow from the feeder channel132into the primary channels130before exiting the chip114through the outlet ports136. In the illustrated embodiment, the multiple different sensors116are arranged along the microfluidic chip114such that each sensor116is associated with a different one of the primary channels130. For example, a first sensor116A may monitor at least a first property of the fluid sample within a first primary channel130A, a second sensor116B may monitor at least a second property of the fluid sample within a second primary channel130B, and so on. Forming the microfluidic chip114to include multiple primary channels130that receive the fluid sample that is monitored by the sensors116may allow for more space for the sensors116as the sensors116can be arranged in an array instead of located side-by-side along the length of a single primary channel130.

Although the microfluidic chip114inFIG. 6includes only one inlet port134, the microfluidic chip114may still monitor the fluid properties of multiple fluidic processes by sequencing or pulsing the flow of fluid through the inlet port134over time, as described with reference toFIGS. 2 and 4. For example, a fluid sample from a first electrolyte bath may be directed (by the fluid input controller170, valves166, and pumps168shown inFIG. 2) through the inlet port134during a first time period, a cleaning fluid may be directed through the inlet port134during a second time period, and a fluid sample from a second electrolyte bath is directed through the inlet port134during a third time period.

FIG. 7illustrates an electrochemical module sensor116integrated within the microfluidic chip114according to an embodiment. The electrochemical module sensor116includes a pH sensor502and a reference electrode504that are both exposed to the fluid sample flowing through the microfluidic channel120. The pH sensor502is spaced apart from the reference electrode504along the length of the channel120. The pH sensor502and the reference electrode504are both conductively connected to a voltage source506. The electrochemical module sensor116may be used to monitor the pH level of the fluid, the impedance of the fluid, the concentration of one or more components (e.g., additives) of the fluid, and/or the like. The pH sensor502and the reference electrode504are mounted to the microfluidic chip114, and may be embedded within the chip114.

The pH sensor502and the reference electrode504may include multiple stacked layers of different material compositions. For example, the pH sensor502may include a silicon layer stacked on top of an aluminum contact, a silicon oxide layer stacked on top of the silicon layer, and an aluminum oxide layer stacked on top of the silicon oxide layer. The reference electrode504in an embodiment includes a silicon oxide layer stacked on top of a silicon layer, and a silver/silver chloride layer stacked on the silicon oxide layer. The generation of an electrical pulse by the voltage source506may affect the electromagnetic properties of the fluid sample proximate to the pH sensor502and the reference electrode504, and the change in the properties of the fluid may be used to measure at least one of the pH, the impedance, or component concentrations of the fluid.

FIGS. 8A, 8B, and 8Cillustrate various embodiments of a UV-VIS sensor116integrated within the microfluidic chip114. The UV-VIS sensor116is configured to perform ultraviolet spectroscopy measurements on the fluid sample flowing through the corresponding microfluidic channel120. The UV-VIS sensor116in theFIG. 8Aoperates in a transmission mode. For example, the UV-VIS sensor116includes a UV-VIS light or white light source606and a UV-VIS detector608. Although spaced apart from the microfluidic chip114in the illustrated embodiment, the UV-VIS light or white light source606and the UV-VIS detector608may be mounted to the microfluidic chip114. For example, the UV-VIS or white light source606is disposed above the channel120and may be connected directly or indirectly to a top side604of the microfluidic chip114. The UV-VIS detector608is disposed below the channel120and may be connected directly or indirectly to an opposite bottom side605of the chip114. The UV-VIS detector608optionally may be a spectrometer. In the transmission mode, the UV-VIS light or white light source606emits light in the ultraviolet wavelength range (e.g., between 10 nm and 800 nm or between 10 nm and 1100 nm) that is directed through the microfluidic channel120and impinges upon the fluid sample therein. The UV-VIS light or white light passes through the channel120and is detected on the other side of the channel120by the UV-VIS detector608, which analyzes the received light. By analyzing how the constituents of the fluid affect the UV-VIS or white light according to spectroscopy techniques, the UV-VIS sensor116may be used to monitor concentrations of various components within the fluid, such as plating brighteners, metallic ions, and/or organic additives.

The UV-VIS sensor116shown inFIG. 8Boperates according to a reflection mode. For example, both the UV-VIS light or white light source606and the UV-VIS detector608are disposed above the top side604of the microfluidic chip114. A reflector610is mounted to the microfluidic chip114below the channel120. The reflector610may be a mirror or another reflective film embedded within the chip114. The UV-VIS light or white light emitted from the light source606reflects off the reflector610after penetrating through the channel120and bounces back towards the UV-VIS detector608for analysis.

The UV-VIS sensor116shown inFIG. 8Coperates according to a fluorescence mode that analyzes fluorescence from the fluid sample. For example, an activator film612may be installed within or on the microfluidic channel120such that the activator film612is exposed to the fluid sample. The activator film612may include fluorescent tags or indicators, such as certain organometallic molecules, dyes, or the like. The activator film612may also include a reflective layer. The light that is emitted from the UV-VIS source606(e.g., between 190 nm and 450 nm) into the microfluidic channel120impinges upon the fluid sample and the activator film612. A fluoresce signal emitted in response is monitored in a fluorescence detector (or fluorometer)614for analysis. The fluorescence detector614is configured to detect intensity changes, fluorescence peak shifts, and/or ratios of different fluorescence peaks in order to monitor specific properties of the sample fluid, such as pH level and component concentrations. It is recognized that the microfluidic chip114may include any of the UV-VIS sensors116shown inFIGS. 8A-C.

FIGS. 9A and 9Billustrate two embodiments of an IR sensor116integrated within the microfluidic chip114. The IR sensor116in bothFIGS. 9A and 9Bincludes an IR emitter or source702and an IR detector704. The IR emitter702is disposed above the corresponding microfluidic channel120, and may be mounted directly or indirectly to a top side604of the microfluidic chip114. The IR emitter702generates a laser pulse of infrared radiation which may penetrate through the microfluidic channel120to interact with the fluid sample within the channel120. The IR sensor116inFIG. 9Aoperates in a transmission mode, such that the IR detector704is disposed below the channel120(e.g., the channel120is between the IR emitter702and the IR detector704). InFIG. 9B, the IR sensor116operates in a reflection mode, such that the IR detector704is on the same side of the channel120as the IR emitter702. Optionally, the IR emitter702and the IR detector704may be disposed within a common housing. The IR sensor116inFIG. 9Bincludes a reflector706to reflect the laser pulse emitted from the IR emitter702back towards the IR detector704. The IR detector704receives the laser pulse (e.g., IR radiation) to analyze how the fluid sample affects the properties of laser pulse. Through the analysis, the IR sensor116is configured to measure the temperature of the fluid sample, and may also measure concentrations of organic additives and/or other components within the fluid sample. The IR emitter702and/or IR detector704may be mounted directly or indirectly to the microfluidic cell114.

FIG. 10illustrates an ultrasound sensor116integrated within the microfluidic chip114according to an embodiment. The ultrasound sensor116includes a signal transducer804that is configured to emit an ultrasonic wave. The signal transducer804may be mounted to the microfluidic chip114, such as to the top side604thereof. The signal transducer804may include an electrical power supply integrated within the transducer804or may be conductively connected to a power source via a wire. In one embodiment, the signal transducer804is a transceiver that both transmits the ultrasonic waves and receives reflected ultrasonic waves. The ultrasonic wave is penetrates through the microfluidic channel120and the fluid sample therein, and is reflected back to the signal transducer804. The transducer804may convert the received signal (e.g., the reflected ultrasonic wave or echo) into an electrical signal for analysis. The transducer804may include internal processors and associated circuitry for analyzing the received signal, or alternatively may transmit the received signal to a discrete detector device which performs the analysis. In an alternative embodiment, the transducer804is used only as a transmitter, and the sensor116further includes a second transducer that is a receiver. The ultrasound sensor116may be used to measure fluidic properties such as fluid level, fluid density, and flow rate through the channel120.