Patent Description:
The present invention relates to a surface temperature sensor device that detects a temperature of a surface.

Surface temperature detectors are designed to be close to or even contact a surface to measure the temperature of the surface. Such temperature detectors are used to provide temperature measurements in temperature sensitive processes. For example, semiconductor processes depend on accurate temperature measurements to control the temperature of various components within processing chambers, such as chuck/pedestal used for forming semiconductor wafers. <CIT> discloses a thermocouple assembly for measuring a pipe surface temperature. The assembly of US'<NUM> has a tubular housing with a bore and a support cap at its end. The thermocouple junction resides at the exterior surface of the support cap.

Typically, a surface temperature detector includes a thermal sensing device, such as a resistive temperature device, that is positioned in a housing. The accuracy of the thermal sensing device varies based on, for example, the thermal conductivity between the housing and the sensing device, the position of the thermal sensing device relative to the surface being measured, the material properties of the thermal sensing device, and other factors. These and other issues are addressed the teachings of the present disclosure.

The present invention is directed toward a temperature detector probe as defined in claim <NUM> that includes a housing, a pair of electrical connectors, a support cap, and a sensor. The housing defines a bore extending longitudinally through the housing. The pair of electrical connectors extend longitudinally through the bore. The support cap is disposed at a first end portion of the housing, and the sensor is provided on the support cap and electrically coupled to the pair of electrical connectors. The support cap is positioned between the pair of electrical connectors and the sensor.

In one form, the temperature detector probe further includes a pair of electrical pins extending through a second end portion of the housing and electrically coupled to the pair of electrical connectors.

In another form, the pair of electrical connectors are POGO pins that are electrically coupled to the sensor via the support cap.

In yet another form, the pair of electrical connectors are a pair of wires that are electrically coupled to the sensor via the support cap.

In one form, the support cap is made of polyamide.

In another form, the support cap includes two plated through-holes to electrically couple the pair of electrical connectors and the sensor.

In yet another form, the sensor is a resistance temperature detector sensor chip.

In one form, the sensor is a thin film resistive element deposited on the support cap, and the thin film resistive element has a high temperature coefficient of resistance. In one variation, the thin film resistive element is one of copper, nickel, nickel-iron, or platinum.

In another form, the temperature detector probe further includes a temperature insulating material disposed on a surface of the sensor.

In yet another form, the sensor is configured to directly contact a surface of an object to measure a temperature of the object.

According to the invention, the housing defines one or more circumferential grooves along an exterior of the housing.

In another form, the sensor is a thermocouple.

In one form, the temperature detector probe further includes a signal processing circuit that is communicably coupled to the sensor to condition a signal from the sensor. In one variation, the housing defines a chamber at a second end portion of the housing, and the signal processing circuit is disposed at the chamber. The pair of electrical connectors are electrically coupled to the signal processing circuit to communicably couple the sensor and the signal processing circuit.

In another form, the present disclosure is directed toward a system comprising an object, and the temperature detector probe of the present disclosure. The temperature detector probe is disposed in the object, and the sensor of the temperature detector probe directly faces the surface of the object.

The present disclosure is directed toward a temperature detector probe that reduces or inhibits thermal conductivity between the probe and an object, and also reduces thermal shunting of the temperature measurement. More particularly, as described herein, the temperature detector probe includes a housing that has grooves circumferentially extending along its exterior at a portion of the probe closest to the surface being measured. The grooves may form a thermal breaker to reduce the transfer of heat between the object and the probe. In addition, the probe includes a sensor that is disposed outside of the housing and is positioned in proximity of or in some forms, directly contacting the surface being measured. This arrangement may improve the response time of the sensor while minimizing thermal shunting. It should be readily understood that the temperature detector probe of the present disclosure addresses other issues, and should not be limited to the examples provided herein.

Referring to <FIG> a temperature detector probe <NUM>, which may also be referred to as a sensor device, is operable to detect the temperature of an object <NUM>, and more particularly, a surface <NUM> of the object <NUM>. The object <NUM> may be, for example, a chuck or pedestal used for processing semiconductor wafers. However, the temperature detector probe <NUM> may be used to detect the temperature of other objects and should not be limited to the examples provided herein.

In one form, the temperature detector probe <NUM> extends through the object <NUM> up to the surface <NUM>. In one form, a gap <NUM> is provided between the temperature detector probe <NUM> and the object <NUM> to reduce thermal conductivity between the object <NUM> and the probe <NUM>. The size of the gap can vary based on the application.

Referring to <FIG> and <FIG>, in one form, the probe <NUM> includes a housing <NUM>, one or more electrical connectors <NUM> (i.e.,<NUM><NUM> and <NUM><NUM>), a support cap <NUM>, and a sensor <NUM>. The housing <NUM> has a first end portion <NUM> and a second end portion <NUM>, and defines a bore <NUM> that extends longitudinally through the housing <NUM> between the first end portion <NUM> and the second end portion <NUM>. In one form, a cap <NUM> is provided at the first end portion <NUM> to prevent foreign matter from entering the probe <NUM>. The housing <NUM> may be viewed as having an extension portion <NUM>, which includes the first end portion <NUM>, and a sensor portion <NUM>, which includes the second end portion <NUM>. When located within the object <NUM>, the sensor portion <NUM> is positioned closer to the surface <NUM> of the object <NUM> than the extension portion <NUM>. In one form, the sensor portion <NUM> of the housing <NUM> includes one or more thermal breaks <NUM> provided as circumferential grooves defined along an exterior of the housing <NUM> to inhibit thermal conductivity between the object <NUM> and the probe <NUM>, and between the extension portion <NUM> and the sensor portion <NUM>. In one form, the thermal breaks <NUM> extend through the housing <NUM>, and in another form, a thin wall of the housing <NUM> is provided between the thermal breaks <NUM> and the bore <NUM>. The housing <NUM> may be made of plastic, such high-performance polyimide-based plastics, such as polyether ether ketone, or other suitable material.

The electrical connectors <NUM> extend through the bore <NUM> to the second end portion <NUM> of the sensor portion <NUM>. The electrical connectors <NUM> are configured to electrically couple and thus, communicably couple the sensor <NUM> to a control system (not shown) that receives signals indicative of the surface temperature of the object. In one example application, the control system is configured to control a heater, such as a pedestal heater. The control system receives the signals from the probe <NUM>, and controls power to the heater system based on the signal and other inputs. This is just one example application,.

The electrical connectors <NUM> extend longitudinally through the bore <NUM> and are electrically coupled to the sensor <NUM>. In one form, the electrical connectors <NUM> are a pair of pins, such as a pair of POGO pins, and each pin includes a lead portion <NUM> (i.e.,<NUM><NUM> and <NUM><NUM>) and a pin portion <NUM> (i.e.,<NUM><NUM> and <NUM><NUM>). The lead portion <NUM> extends through the first end portion <NUM> and is configured to electrically couple to a control system via a cable/wire connection. The pin portion <NUM> extends from the lead portion <NUM> to the second end portion <NUM> and is electrically coupled to the sensor <NUM>. The electrical connectors may be configured in other suitable ways, an example of which is provided below.

The support cap <NUM> is located at the second end portion <NUM>, and is configured to align and support the sensor <NUM> with the surface <NUM> of the object <NUM>. In one form, the support cap <NUM> has a disk like shape and is made of a low thermal conductive material, such as polyamide, to inhibit thermal conductivity between the sensor <NUM> and the housing <NUM>. Other materials may include elastomeric materials such as polydimethylsiloxanes. The support cap <NUM> includes a first surface that faces the bore <NUM> and a second surface that is exposed to the environment. The support cap <NUM> is configured in various suitable ways based on the size of the sensor <NUM> and packaging size of the probe <NUM>. For example, in one form, the thickness of the support cap <NUM> is approximately <NUM> to <NUM> inch. The support cap <NUM> is also configured to electrically couple the sensor <NUM> to the electrical connectors <NUM>. In one form, with the sensor <NUM> being a surface mount device, the support cap <NUM> includes plated through holes <NUM> (i.e., <NUM><NUM> and <NUM><NUM>) that electrically couple to solder pads of the sensor <NUM> and to the electrical connectors <NUM>. Other suitable methods for electrically coupling the sensor <NUM> to the electrically connectors <NUM> via the support cap <NUM> may also be used while remaining within the scope of the present disclosure.

The sensor <NUM> is operable to measure a temperature of the surface <NUM>, and outputs a signal indicative of the temperature to the control system. In one form, the sensor <NUM> is a resistance temperature detector (RTD) type sensor that is located on the support cap <NUM>, and more particularly, along a second surface of the support cap <NUM>. In <FIG>, the sensor <NUM> is provided as a RTD surface mount device that generally includes a case and a resistive element having a high temperature coefficient of resistance (TCR) disposed within the case. For example, the resistive element may be, but is not limited to, copper, nickel, nickel-iron, or platinum. The RTD surface mount device is mounted to the support cap <NUM> via reflow solder. In one example implementation, the RTD surface mount device follows an industry standard <NUM> size (<NUM> X <NUM>) for surface mount devices, and has a <NUM> thickness and has a mass of <NUM>. In another form, the sensor <NUM> is a thermocouple mounted to the surface of the support cap <NUM>.

Based on the application, the sensor <NUM> is configured to directly contact or be in proximity to the surface <NUM> of the object <NUM> to measure a temperature of the surface <NUM>. In one form, the support cap <NUM> has resilient or elastic qualities, such that the position of sensor <NUM> is flexible to contact the surface <NUM> of the object <NUM>. In addition, with the electrical connectors <NUM> being POGO pins, the pins provide a biasing force against the support cap <NUM> and the sensor <NUM> to have the sensor <NUM> contact the surface <NUM>.

In operation, the probe <NUM> is positioned in the object <NUM>, and is electrically coupled to the control system by way of the electrical connectors <NUM> and wires. The sensor <NUM> may be in direct contact with or is proximity to the surface <NUM> to measure the temperature of the surface <NUM>. The control system is communicably coupled to the sensor <NUM>, and receives a signal that is indicative of temperature from the sensor <NUM>.

By way of the support cap <NUM> and the housing <NUM> having the grooves, the thermal conductivity between probe <NUM> and the object and between the sensor <NUM> and the housing <NUM> is reduced or inhibited to potentially improve, for example, accuracy, response time, and offset errors of the sensor.

<FIG> illustrate another variation of a temperature detector probe that has different electrical connectors and sensor. Specifically, in one form, a temperature detector probe <NUM> includes the housing <NUM>, a pair of electrical pins or leads <NUM> (i.e., <NUM><NUM> and <NUM><NUM>), a pair of electrical connectors <NUM> (i.e., <NUM><NUM> and <NUM><NUM>), a support cap <NUM>, and a sensor <NUM>. The electrical leads <NUM> are operable to electrically couple the probe <NUM> to the control system, and extend through the first end portion <NUM> of the housing <NUM>. The probe <NUM> further includes a cap <NUM> disposed at the first end portion <NUM> to prevent foreign material from entering the housing <NUM>.

The electrical connectors <NUM> are wires that are connected to the leads <NUM>, for example, solder or spot welding, and may be referred to as wires <NUM>. In one form, the electrical connectors <NUM> are small gauge wires, such as <NUM> to <NUM> gauge. Like the electrical connectors <NUM> of probe <NUM>, the wires <NUM> extend through the bore <NUM> and are electrically coupled to the sensor <NUM> via the support cap <NUM>.

In one form, the sensor <NUM> is a resistive element <NUM> having a high TCR that is deposited on the support cap <NUM>. That is, in lieu of mounting a case having the resistive material disposed therein, the probe <NUM> provides the resistive material directly on the support cap <NUM>. Accordingly, when disposed in the object, the resistive material is directly in contact with or in close proximity to the surface of the object, and thus, may increase the response time of the sensor <NUM> and reduce thermal shunting.

In one form, the support cap <NUM> is a rigid disk of low thermal expansion material such as quartz, silicon, aluminum oxide (Al2O3), aluminum nitride (AIN). In another form, the support cap <NUM> is made of a metal substrate such as stainless steel or Invar coated with a dielectric to insulate the resistive element (i.e. sensor <NUM>) from the substrate. Similar to the probe <NUM>, a plated through hole may be formed in the support cap <NUM> to electrically couple the sensor <NUM> (i.e., resistive material) to the electrical connectors <NUM>, and thus, to the control system. The support cap <NUM> could also be configured in a skeletonized structure to further reduce thermal loss between the sensor <NUM> and the support cap <NUM>.

Referring to <FIG>, the temperature detector probe <NUM>, <NUM> may be provided with additional support for providing flexibility to the sensor and support cap. More particularly, a temperature detector probe <NUM> is configured in a similar manner as probe <NUM>, but includes the sensor <NUM> and support cap <NUM> of probe <NUM>. The probe <NUM> further includes a retainer ring <NUM> disposed at the second end portion <NUM> of the housing <NUM> and a temperature insulating material <NUM> (TIM) provided on the sensor <NUM>. The retaining ring <NUM> secures the support cap <NUM> to the housing <NUM>.

The TIM <NUM> is provided on the sensor <NUM>, such that the TIM <NUM> is between the sensor <NUM> and the surface being measured. The thickness of the TIM <NUM> may be based on the application using the probe <NUM>, and the structure of the support cap <NUM> and sensor <NUM>. For example, with the support cap <NUM> being <NUM> to <NUM> microns thick, the TIM <NUM> may be <NUM> to <NUM> microns thick. In one form, the TIM <NUM> is a sheet material or molded in place material that is deposited to the exposed surface of the sensor <NUM>. The TIM <NUM> is made from low hardness polymers or gels often silicone based and a combination of solid powder materials such as boron nitride, various metal oxides or metals to provide the thermal conductivity. The polymer is essentially a binder that holds this sophisticated combination of solids in usable form typically a sheet available in various thicknesses to fit the application or a dispensable liquid or paste form which may cure into a more stable soft solid material. Examples of TIM materials are Fujipoly, Sarcon, SPG20A, Sarcon GTR or Sarcon QR. The TIM <NUM> improves the thermal interface of the sensor <NUM> to the surface of the object to improve the accuracy of the temperature measurement.

Referring to <FIG>, a temperature detector probe <NUM> provides another configuration for supporting and providing flexibility to the sensor. In one form, the probe <NUM> includes the wires (i.e., electrical connectors <NUM>) and leads <NUM> of probe <NUM> to electrically couple the sensor <NUM> to the control system. Here, the probe <NUM> includes a support cap <NUM> provided at the second end portion <NUM> of the housing <NUM>. In one form, the support cap <NUM> is made of elastomer, and may be configured in various suitable ways to support the sensor <NUM>. For example, in one form, the support cap <NUM> includes a wall <NUM> that interfaces with an inner-wall of the housing <NUM>, and defines a cavity <NUM> for housing the sensor <NUM> and access ports <NUM> (i.e., <NUM><NUM> and <NUM><NUM>) for receiving the wires.

In one form, the temperature detector probe of the present disclosure may also include additional circuitry to process the signal from the sensor prior to providing the signal to the control system. For example, referring to <FIG>, a probe <NUM> is configured in a similar manner as probe <NUM>, <NUM>, <NUM> and includes wires, as the electrical connectors, and leads <NUM>. In one form, the probe <NUM> includes a signal processing circuit (SPC) <NUM> disposed in a chamber <NUM> defined within the housing <NUM>. The SPC <NUM> is electrically coupled to the sensor (not shown) with a first set of wires <NUM> (i.e., <NUM><NUM> and <NUM><NUM>), and to the leads <NUM> via a second set of wires <NUM> (i.e., <NUM><NUM> and <NUM><NUM>). Accordingly, the wires <NUM> and <NUM> form electrical connectors that electrically couple the sensor <NUM> to the SPC <NUM>, and the SPC <NUM> to the leads <NUM>.

The SPC <NUM> may be configured in various suitable ways to condition the original signal from the sensor <NUM> prior to transmitting the signal to the control system. For example, in one form, the SPC <NUM> includes one or more electrical components to, for example, filter noise from the original signal, increase the strength of the signal, convert the signal to a particular to format utilized by the control system, convert the signal to a digital value, and/or perform a sensor offset correction. With the SPC <NUM>, the probe <NUM> can be customized for a particular control system to provide an enhanced signal based on the original signal from the sensor. In addition, SPC <NUM> is thermally interfaced to the housing <NUM>, and the housing <NUM> is thermally interfaced by direct contact such as an interference fit or through use of a TIM to the object <NUM>. The temperature of the object <NUM> is actively controlled and therefore, maintains SPC <NUM> at temperatures compatible with SPC circuitry and materials. In other words, a thermal path provided between the SPC <NUM> and the object <NUM> controls the temperature of the SPC <NUM> at temperatures substantially the same as that of the object <NUM>, which is controlled at temperatures compatible with electronic circuitry.

The various variations among the different probes may be interchangeable. For example, the probe <NUM> of <FIG> may include the leads <NUM> and the electrical connectors <NUM> in lieu of the electrical connectors <NUM>. Conversely, the probes <NUM>, <NUM>, <NUM> and <NUM> may include the electrical connectors <NUM> of <FIG> in lieu of the leads <NUM> and the electrical connectors <NUM>.

In yet another variation, each of the probes <NUM>, <NUM>, <NUM>, <NUM> and <NUM> may be configured to hold an insulating gas. For example, with the grooves <NUM> separated from the bore <NUM> by a wall, the probe <NUM> may be filled with an insulating gas, such as Argon, to further inhibit thermal conductivity between the housing <NUM> and the sensor <NUM>.

The temperature detector probes of the present disclosure are configured to inhibit thermal conductivity between the sensor from the surrounding components, such as the housing, to improve the accuracy of the measured temperature of a surface. Additional improvements to the measurement are also provided by having the sensor interface directly with the surface being measured. The addition of a TIM to the sensor surface improves thermal interfacing and sensor repeatability with the surface being measured. The flexible support cap provides a constant force against the sensor, the TIM, and the surface being sensed.

Claim 1:
A temperature detector probe (<NUM>, <NUM>, <NUM>) comprising:
a housing (<NUM>) defining a bore (<NUM>) extending longitudinally through the housing (<NUM>);
a pair of electrical connectors (<NUM>, <NUM>) extending longitudinally through the bore (<NUM>);
a support cap (<NUM>, <NUM>) disposed at a first end portion of the housing (<NUM>), wherein the support cap (<NUM>, <NUM>) has a first surface that faces the bore (<NUM>) and a second surface opposite of the first surface, the second surface being exposed to an environment, wherein the second surface is continuously even and forms a distal end of the support cap (<NUM>, <NUM>); and
a sensor (<NUM>, <NUM>) provided on the second surface of the support cap (<NUM>, <NUM>) and electrically coupled to the pair of electrical connectors (<NUM>, <NUM>), wherein:
the support cap (<NUM>, <NUM>)
is positioned between the pair of electrical connectors (<NUM>, <NUM>) and the sensor (<NUM>, <NUM>),
wherein the housing (<NUM>) includes one or more thermal breaks (<NUM>) provided as circumferential grooves to inhibit thermal conductivity between an object being measured and the probe, wherein the one or more thermal breaks (<NUM>) are defined along an exterior of the housing (<NUM>) with a thin wall of the housing (<NUM>) provided between the one or more thermal breaks (<NUM>) and the bore (<NUM>), and
the sensor (<NUM>, <NUM>) forms a distal end of the temperature detector probe.