Patent Description:
In general, the use of thin film applications for creating sensor devices (e.g., thermocouples (TC) or resistance temperature detectors (RTD)) applied to high temperature applications (e.g., for turbine engine vanes, blades, shrouds, or combustor panels) can require the eventual electrical connection of the thin film device back to signal conditioning equipment and/or data acquisition systems. The electrical connection most often will require it to be at or near the high-temperature location that the sensor device (e.g., TC or RTD) is installed. The electrical wires are then routed out to a more adequate temperature environment where the instrumentation and control system reside.

For some thin film sensor devices applied to a hot side surface (e.g., of an aero turbine engine component), the thin film sensor devices can be exposed to hot gas temperatures (e.g., in the range of <NUM> to <NUM> (<NUM> °F to <NUM> °F) ). The electrical wires typically need to be connected to the thin film sensor to complete the circuit of the sensor, and the wires can be passed to a less severe environment to the power and/or data acquisition system of the sensor. <CIT> discloses a film thermocouple temperature sensor. Two wires are crossing a support and each wire contacts a layer of the film sensor.

The present disclosure provides for electrical connectivity to high temperature film sensor devices (e.g., temperature sensor devices). More particularly, the present disclosure provides for high temperature, thin film sensor devices (e.g., temperature sensor devices) having connection of wires and cabling from the cold side to the thin film sensor on the hot side.

The present disclosure provides for a thin film sensor assembly including a component wall having a hole therethrough, the component wall having a cold side and a hot side; a cable positioned in the hole, the cable having a first wire and a second wire; a layer of low dielectric material positioned on the hot side of the component wall, with a first length of the first wire positioned on the layer of low dielectric material, and a second length of the second wire positioned on the layer of low dielectric material; and a first trace of film material in electrical connection with the first length of the first wire positioned on the layer of low dielectric material and a second trace of film material in electrical connection with the second length of the second wire positioned on the layer of low dielectric material; wherein the first and second traces of film material are in electrical communication with a sensor positioned on the layer of low dielectric material.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the component wall is a wall of an aero turbine engine component; and wherein the cold side is an internal cooling air cavity side of the aero turbine engine component, and the hot side is an external gas path side of the aero turbine engine component.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the sensor is a high temperature, thin film temperature sensor.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the sensor is a thermocouple or a resistance temperature detector.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the sensor is positioned proximal to the hot side.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the layer of low dielectric material comprises a ceramic material.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the cable comprises a sheathing, the sheathing comprising a metal material.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the component wall is a wall of a vane of an aero turbine engine component.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the cable is routed and mounted or strain-relieved on the cold side of the component wall and routed to a terminal connection or system equipment.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, the first and second wires comprise electrically conductive metal materials.

The present disclosure provides for a method for fabricating a thin film sensor assembly including providing a component wall having a hole therethrough, the component wall having a cold side and a hot side; positioning a cable in the hole, the cable having a first wire and a second wire; positioning a layer of low dielectric material on the hot side of the component wall; positioning a first length of the first wire on the layer of low dielectric material; positioning a second length of the second wire on the layer of low dielectric material; providing a first trace of film material in electrical connection with the first length of the first wire positioned on the layer of low dielectric material; providing a second trace of film material in electrical connection with the second length of the second wire positioned on the layer of low dielectric material; and positioning a sensor on the layer of low dielectric material, the first and second traces of film material in electrical communication with the sensor.

In addition to one or more of the features described, or as an alternative to any of the foregoing embodiments, further comprising after positioning the first and second lengths of the first and second wires on the layer of low dielectric material, providing and curing additional dielectric material over the first and second lengths of the first and second wires, and then removing a portion of the additional dielectric material over the first and second lengths of the first and second wires.

Additional features, functions and applications of the disclosed assemblies, systems and methods of the present disclosure will be apparent from the description which follows, particularly when read in conjunction with the appended figures.

With reference to the accompanying drawings, like elements are numbered alike.

Features and aspects of embodiments are described below with reference to the accompanying drawings, in which elements are not necessarily depicted to scale.

Example embodiments of the present disclosure are further described with reference to the appended figures. It is to be noted that the various features, steps, and combinations of features/steps described below and illustrated in the figures can be arranged and organized differently to result in embodiments which are still within the scope of the appended claims.

To assist those of ordinary skill in the art in making and using the disclosed assemblies, systems and methods, reference is made to the appended figures, wherein:.

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the figures.

The example embodiments disclosed herein are illustrative of thin film sensor assemblies, and systems of the present disclosure and methods/techniques thereof. It should be understood, however, that the disclosed embodiments are merely examples of the present disclosure, which may be embodied in various forms. Therefore, details disclosed herein with reference to example thin film sensor assemblies and associated processes/techniques of fabrication/assembly and use are not to be interpreted as limiting, but merely as the basis for teaching one skilled in the art how to make and use the assemblies/systems and/or alternative assemblies/systems of the present disclosure.

As noted above, current practice provides that for some thin film sensor devices applied to a hot side surface (e.g., of an aero turbine engine component), the thin film sensor devices can be exposed to hot gas temperatures (e.g., in the range of <NUM> to <NUM> (<NUM> °F to <NUM> °F) ). The electrical wires typically need to be connected to the thin film sensor to complete the circuit of the sensor, and the wires typically are passed to a less severe environment (e.g., to the signal conditioning and/or data acquisition system of the sensor). The present disclosure advantageously provides for high temperature, thin film sensor devices (e.g., temperature sensor devices) having connection of wires and cabling from the cold side to the thin film sensor on the hot side, as discussed further below.

As also noted above, the use of thin film applications for creating sensor devices (e.g., thermocouples (TC) or resistance temperature detectors (RTD)) applied to high temperature applications (e.g., for turbine engine vanes, blades, shrouds, or combustor panels) can require the eventual electrical connection of the thin film device back to the signal conditioning and/or data acquisition system. The electrical connection most often will require it to be at or near the high-temperature location that the sensor device (e.g., TC or RTD) is installed. The electrical wires are then routed out to a more adequate temperature environment where the instrumentation and control system reside. The present disclosure advantageously provides assemblies, systems and methods for that electrical connection to the leads or traces of the thin film sensor device (e.g., thin film temperature sensor device such as a TC/RTD device) at the hot-cold barrier that exists in high temperature components (e.g., high temperature components in aero turbine engine applications). It is noted that the present disclosure is not limited to TCs or RTDs or the like, and the assemblies, systems and methods of the present disclosure can be applied to any thin film device (e.g., sensor devices, such as, for example, strain gauges, heat flux sensors, etc.) that can be applied to the surface of a high temperature component.

It is noted that some conventional thermocouples are two-wire devices where the wires are dissimilar metals that are chosen such that when joined at a point create a voltage when that junction is exposed to a temperature different from a known reference temperature. Platinum and platinum-rhodium of various ratios are common thermocouple wire pairs for high temperature applications.

A resistance temperature device (RTD) uses identical materials for its wires, usually platinum, nickel, or copper; platinum is common for its properties at higher temperatures. An RTD measures the change of resistance as a function of temperature at the point of measurement where the resistance is higher due to its arrangement, usually made up of a long length of reduced cross-sectional area wire or film arranged in a serpentine pattern. Also, depending on the required accuracy and arrangement, an RTD can be a two-wire, three-wire, or a four-wire device.

Applying thin films to create a sensor device (e.g., thermocouple) can require applying high temperature metals or other materials that can be printed or sputtered onto the component surface. Typically, the material used for fabricating the aero turbine engine component (e.g., vane, etc., or other aero turbine engine component) will be electrically conductive and will require a thin barrier applied to the surface that has a low dielectric property and is applied where the then film device and traces are to be applied. The thin film sensor (e.g., thermocouple) will use dissimilar materials for each thin film leg (e.g., thermocouple leg) which then come together to form the junction (e.g., thermocouple junction) at the point of measurement. Similarly, a thin film application for a resistance temperature device can require the printing or sputtering of two to four platinum or other material to create the traces connecting to the printed or sputtered serpentine pattern at the point of measurement. Other thin film sensor devices can be applied in a similar fashion depending on its form, function, and/or material requirements.

<FIG> is a top view of a thin film sensor assembly <NUM> (e.g., thin film temperature sensor assembly <NUM>) according to certain embodiments of the present disclosure. <FIG> is a cross-sectional side view of the thin film sensor assembly <NUM> of <FIG> is another cross-sectional side view of the thin film sensor assembly <NUM> of <FIG> (rotated <NUM> degrees relative to <FIG>).

In general and as shown in <FIG>, example thin film sensor assembly <NUM> includes a component wall <NUM> having at least one hole or opening <NUM> therethrough. In example embodiments, the component wall <NUM> is a wall <NUM> of an aero turbine engine component. For example and without limitation, component wall <NUM> can be a wall <NUM> of a vane or the like of an aero turbine engine component.

Each hole or opening <NUM> (e.g., small hole/opening <NUM>) in component wall <NUM> can be machined or fabricated through the wall <NUM>. It is noted that the number of holes <NUM> depends on the number of thin film traces <NUM> and/or the number of wires <NUM> per cable <NUM>, as discussed below. For an example two-wire 15A, 15B thin film thermocouple or the like, a single hole <NUM> can be required to allow a two-wire 15A, 15B cable <NUM> to pass through from the cold side <NUM> (e.g., cooling air cavity side <NUM>) to the hot side <NUM> (e.g., hot gas path side <NUM>) of the component wall <NUM> (e.g., wall <NUM> of a vane or the like of an aero turbine engine component), as shown in <FIG>.

An end <NUM> of the sheathing <NUM> of cable <NUM> can be flush or just below or above the surface of the hot side <NUM> of the component wall <NUM>, and short lengths of a first wire 15A and a second wire 15B from the cable <NUM> can extend beyond the surface of the hot side <NUM> of the component wall <NUM>. The first and second wires 15A, 15B can be bent down (e.g., bent <NUM> degrees down) away from each other and laid down on a low dielectric barrier <NUM> or layer of low dielectric material <NUM> applied on the hot side <NUM> of the component wall <NUM>.

A thin layer of low dielectric material <NUM> (e.g., the same low dielectric material <NUM> as noted above) can be applied and cured over the leads defined by the short lengths of first and second wires 15A, 15B laid down on material/barrier <NUM> to contain the leads of 15A, 15B securely (and to encapsulate end <NUM> of cable <NUM>). The surface at and around the ends of leads of 15A, 15B can be sanded (e.g., lightly sanded) or gradually removed to remove the low dielectric material <NUM> over the ends of wires 15A, 15B, and to expose the ends of metal wires 15A, 15B for the purpose of electrical connection with the first trace 17A and the second trace 17B, respectively, as described below. It is noted that the removal of the material <NUM> can expose the wires 15A, 15B, but nothing else of the cable <NUM> below.

In an example embodiment and without limitation, the low dielectric material <NUM> can be a slurry of mullite ceramic powder in a liquid carrier and activator, typically a refractory ceramic colloid water.

In an example embodiment and without limitation, the cable <NUM> can include a thin wall metal sheathing <NUM> containing or housing two electrically conductive metal materials, first and second wires 15A, 15B. The choice of materials for the first and second wires 15A, 15B can depend on the temperature capability needed of the material and its electrical properties, and for a high temperature example platinum can be required.

For an example of a high temperature thin film thermocouple of assembly <NUM>, typically the first and second wires 15A, 15B should match the material as the film traces 17A, 17B, otherwise a thermocouple junction can be created at each electrical connection where materials are not identical.

For an example resistance temperature device of assembly <NUM>, the first and second wires 15A, 15B need not match the trace materials 17A, 17B, but they should have adequate temperature capability for the particular use case.

The first and second wires 15A, 15B can be encapsulated in a ceramic powder material <NUM> providing space and insulation from each wire 15A, 15B and the outer sheathing <NUM>. The sheathing <NUM> can also be a high temperature metal material (e.g., Inconel <NUM> or platinum or the like). The cable <NUM> can be routed and mounted and strain-relieved on the cold side <NUM> of the component wall <NUM> and routed to its terminal connection and/or system equipment or the like.

With the leads defined by the short lengths of first and second wires 15A, 15B laid down on material/barrier <NUM> in place and after sanding them as described above, the process of applying the traces 17A, 17B and thin film sensor <NUM> to the layer <NUM> of thin low dielectric can proceed. This process can include a masking of the surface <NUM> to expose only the portion of the surface <NUM> that will define the traces 17A, 17B of the sensor <NUM> and the sensor <NUM> itself. The traces 17A, 17B can be routed in such a manner as to intersect the <NUM>° bent wires 15A, 15B from cable <NUM> as appropriate for the function of sensor <NUM>. With a mask in place, a thin film material can be applied to provide the traces 17A, 17B of the sensor <NUM> and the sensor <NUM> itself, and the application of such a thin film material over each wire 15A, 15B will complete the circuit of the sensor <NUM> (via traces 17A, 17B providing electrical connection with the first and second wires 15A, 15B, respectively).

It is noted that the thin low dielectric layer <NUM> provides electrical insulation from the electrically conductive component of sensor <NUM> and traces 17A, 17B.

There are many benefits of the assemblies <NUM>, systems and methods of the present disclosure, including, without limitation, that the order of an example process can require the wires 15A, 15B to be in place prior to printing the sensor material on the component surface, eliminating the difficult process of welding wire onto the sensors thin film contact; as such this can improve the likelihood of successful electrical connection between wires 15A, 15B and traces 17A, 17B.

This disclosure is further illustrated by the following examples, which are non-limiting.

A technique was developed in which thin platinum wires <NUM> (<NUM> inch (<NUM>) diameter) were embedded within the surface layers of a mullite coating on a SiC/SiC ceramic matrix composite (CMC) onto which thin film leads <NUM> were deposited directly onto the exposed (embedded) wires <NUM> as shown in <FIG>. The thin film leads <NUM> were deposited directly onto the platinum wires <NUM> and formed an ohmic contact. They did not require welding or conductive pastes to facilitate a mechanically robust connection because the thin film leads <NUM> were sputter-deposited onto the embedded wire <NUM>.

The layer of mullite was heat treated. SiC grinding/polishing paper was used to expose the flattened end of the embedded wire <NUM> so that a small portion of the wire surface was exposed. The final step was to deposit the thin film thermocouple leg or lead <NUM> over the exposed embedded wire <NUM> to form an ohmic contact and provide a reproducible thermoelectric response. <FIG> is a graph showing the thermoelectric response of a Pt:ITO (indium tin oxide) thin film thermocouple that was connected to embedded Pt wires; the temperature was ramped from <NUM> to <NUM> °F (<NUM> to <NUM>).

The ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of "up to <NUM> wt. %, or, more specifically, <NUM> wt. % to <NUM> wt. %", is inclusive of the endpoints and all intermediate values of the ranges of "<NUM> wt. % to <NUM> wt. "Combinations" is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms "first," "second," and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. "Or" means "and/or" unless clearly stated otherwise. Reference throughout the specification to "some embodiments", "an embodiment", and so forth, means that a particular element described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments.

Claim 1:
A thin film sensor assembly (<NUM>) comprising:
a component wall (<NUM>) having a hole therethrough, the component wall (<NUM>) having a cold side (<NUM>) and a hot side (<NUM>);
a cable (<NUM>) positioned in the hole, the cable (<NUM>) having a first wire (15A) and a second wire (15B);
a layer of low dielectric material (<NUM>) positioned on the hot side (<NUM>) of the component wall (<NUM>), with a first length of the first wire (15A) positioned on the layer of low dielectric material (<NUM>), and a second length of the second wire (15B) positioned on the layer of low dielectric material (<NUM>); and
a first trace of film material (17A) in electrical connection with the first length of the first wire (15A) positioned on the layer of low dielectric material (<NUM>) and a second trace of film material (17B) in electrical connection with the second length of the second wire (15B) positioned on the layer of low dielectric material (<NUM>);
wherein the first and second traces of film material (17A, 17B) are in electrical communication with a sensor (<NUM>) positioned on the layer of low dielectric material (<NUM>).