The present application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Serial No. 62/018,092, filed Jun. 27, 2014, and titled “TOUCH PANEL DIELECTRIC COVER WITH THROUGH-GLASS VIAS AND METHOD.”U.S. Provisional Application Serial No. 62/018,092 is herein incorporated by reference in its entirety.
A thermopile is an electronic device that converts thermal energy into electrical energy. A thermopile can include several thermocouples coupled together. Thermopiles are used to provide an output voltage in response to temperature as part of a temperature measuring device, where the output voltage is proportional to a local temperature difference (e.g., a temperature gradient).
A temperature sensing device and method for fabrication of the temperature sensing device are described that include a first temperature sensor, a second temperature sensor, a resistance temperature detector, a thermopile, and/or a reference thermopile disposed on and/or within the lid assembly. In an implementation, the temperature sensing device includes a substrate, a support structure disposed on the substrate, a thermopile disposed on the substrate, a first temperature sensor disposed on the substrate, and a lid assembly disposed on and/or coupled to the ceramic structure, where the lid assembly includes a base layer, a first filter layer disposed on a first side of the base layer, a first metal layer disposed on a second side of the base layer, a passivation layer disposed on the first metal layer, where the passivation layer includes at least one of a second metal layer, a via, a metal plate, or an epoxy ring, and a second temperature sensor disposed on and/or in the passivation layer.
In an implementation, a process for fabricating the temperature sensing device that employs example techniques in accordance with the present disclosure includes receiving a substrate having a thermopile, a first temperature sensor, and a ceramic structure disposed on the substrate, and placing a lid assembly on the ceramic structure, where the lid assembly includes a base layer, a first filter layer disposed on a first side of the base layer, a first metal layer disposed on a second side of the base layer, a passivation layer disposed on the first metal layer where the passivation layer includes at least one of a second metal layer, a via, a metal plate, or an epoxy ring, and a second temperature sensor disposed on the passivation layer, where the second temperature sensor is exposed to the cavity. The temperature sensing device provides a more accurate calibration and temperature measurement by compensating for a temperature gradient within the device.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
The detailed description is described with reference to the accompanying figures. The use of the same reference numbers in different instances in the description and the figures may indicate similar or identical items.
Temperature sensing devices are becoming more prevalent in portable electronic devices. Thermopiles are often used for temperature sensing in semiconductor and electronic devices. Most temperature sensing devices and systems work well when there is not a thermal gradient in the package. However, many devices create heat internally, which can create an error when calibrating the device and calculating a temperature external to the device. The device and method herein includes placing a temperature sensor on the lid and in the cavity to measure and compensate for the thermal gradient in the package and achieve a high accuracy temperature measurement.
Accordingly, a temperature sensing device and method for fabrication of the temperature sensing device are described that include a second temperature sensor disposed on and/or in the lid assembly or multiple thermopiles. In an implementation, the temperature sensing device includes a substrate, a ceramic structure disposed on the substrate, a thermopile disposed on the substrate, a first temperature sensor disposed on the substrate, and a lid assembly disposed on the ceramic structure, where the lid assembly includes a base layer, a first filter layer disposed on a first side of the base layer, a first metal layer disposed on a second side of the base layer, a passivation layer disposed on the first metal layer, where the passivation layer includes at least one of a second metal layer, a via, a metal plate, or an epoxy ring, and a second temperature sensor disposed on and/or in the passivation layer. In another implementation, the temperature sensing device can include a reference thermopile instead of a surface mountable first temperature sensor or a second temperature sensor. In implementations, a process for fabricating the temperature sensing device that employs example techniques in accordance with the present disclosure includes receiving a substrate having a thermopile, a first temperature sensor, and a ceramic structure disposed on the substrate, and placing a lid assembly on the ceramic structure, where the lid assembly includes a base layer, a first filter layer disposed on a first side of the base layer, a first metal layer disposed on a second side of the base layer, a passivation layer disposed on the first metal layer, where the passivation layer includes at least one of a second metal layer, a via, a metal plate, or an epoxy ring, and a second temperature sensor disposed on the passivation layer, where the second temperature sensor is exposed to the cavity.
The temperature sensing device disclosed herein provides improved sensitivity by placing the second temperature sensor on the lid assembly as well as in the cavity or including a reference thermopile. A second temperature sensor can allow temperature gradient measurement within the semiconductor package when the temperature of the semiconductor package is measured.
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The temperature sensing device 100 may include a first temperature sensor 108 disposed on the substrate 102. In one implementation, a first temperature sensor 108 can include a thermocouple. A thermocouple may include a temperature-measuring device including two dissimilar conductors that contact each other at one or more points and produces a voltage when the temperature of one of the points differs from the reference temperature at other parts of the circuit. Other examples of the first temperature sensor 108 can include a resistance temperature detector (RTD), a resistor, a thermistor, and/or a negative temperature coefficient (NTC) thermistor. It is contemplated that the first temperature sensor 108 can include other types of temperature sensors. The first temperature sensor 108 can be disposed on the substrate 102 (the hot side of the temperature sensing device 100) and can be configured to measure the temperature of the substrate 102 and/or the energy created within the temperature sensing device 100.
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In embodiments, the lid assembly 136 can include a base layer 114. The base layer 114 may include a material is configured to provide mechanical support for other layers and functional devices as a part of the lid assembly 114. In one specific embodiment, the base layer 114 can include a layer of silicon. The base layer 114 can be configured to allow energy and/or light to pass through an aperture 132. In some embodiments, the aperture 132 can include a lens. In an embodiment, the base layer 114 includes a first filter layer 116 disposed on a first side (e.g., side distal from the substrate 102) of the base layer 114. The first filter layer 116 can include, for example, a light filter, an anti-reflective layer, and/or other material. In one specific embodiment, the first filter layer 116 can include an anti-reflective film. In another specific embodiment, the first filter layer 116 can include an ultraviolet light filter. It is contemplated that other filter types and/or light-altering layers can be utilized alone or in combination as a first filter layer 116. In some additional embodiments, a second filter layer 116 may be formed on and/or disposed on a second side (e.g., side closest to the substrate 102) of the base layer 114. In these embodiments, the second filter layer 116 can include a light filter and/or an anti-reflective coating as disclosed above. In a specific embodiment, the second filter layer 116 can include a low emissivity filter layer configured to minimize the effect of the first temperature sensor 108 and/or another filter layer with a known emissivity.
A first metal layer 120 can be disposed on the base layer 114 and/or the second filter layer 118, as illustrated in
At least one passivation layer 122 may be formed on the first metal layer 120. The passivation layer 122 may include an electrical insulator that functions as an insulator and/or a protective layer between metal layers and other components of the temperature sensing device 100. In one embodiment, the passivation layer 122 can include a layer or layers of silicon dioxide (SiO2) formed on the first metal layer 120. In another embodiment, the passivation layer 122 may include a thin film (e.g., benzocyclobutene (BCB), etc.). In implementations, the passivation nlayer 122 can include one or more material layers that may include the same or different dielectric materials. In implementations, the passivation layer 122 can be formed and/or deposited on the first metal layer 120 using deposition (e.g., physical vapor deposition, chemical vapor deposition, spin coating, etc.) and/or etching techniques. In the example shown in
In some implementations, at least one via 124 may be formed in the passivation layer 122. The via(s) 124 can include a through-hole electrical connection between at least two different layers in the temperature sensing device 100 and/or lid assembly 136 (e.g., a vertical connection between the first metal layer 120 and the second metal layer 126). Some examples of vias can include a through via, a blind via, a buried via, etc. The via(s) 124 may be back filled with an electrical conductor, such as gold, tungsten, copper, etc., in order to form the electrical connection. In implementations, the via(s) 124 can be formed using deposition, mask, and etching fabrication techniques.
In embodiments, a second metal layer 126 may be formed on and/or in a portion of the passivation layer 122. The second metal layer 126 can be deposited using deposition and etching fabrication techniques similar to the other metal layers disclosed herein. In an implementation, a second metal layer 126 can be deposited such that it functions as an electrical interconnection between different components and/or different conducting layers within the temperature sensing device 100 (e.g., a temperature sensor and an electrical connection in the support structure 104). In one specific instance as illustrated in
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In some embodiments, a second temperature sensor 112 may be coupled to the lid assembly 136. In one specific instance, the second temperature sensor 112 can include a thermocouple. In the embodiment shown in
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In implementations, the circuitry within the application-specific integrated circuit 154 may include analog-to-digital converter circuitry, programmable-gain amplifier (PGA) circuitry, fixed-gain amplifier circuitry, combinations thereof, or the like. The application-specific integrated circuit 154 can be configured to receive the electrical signal from the thermopile 110, the electrical signal from the resistance temperature detector 152, the reference thermopile 150, the first temperature sensor 108, and/or the second temperature sensor 112 to generate a signal representing a temperature associated with an object outside the temperature sensing device 100. In an embodiment, the application-specific integrated circuit 154 can be configured to compare (e.g., subtract, remove, add, etc.) the electrical signal that is common to both electrical signals (e.g., the electrical signal that represents the electromagnetic radiation associated with the package) with the electrical signal from the thermopile 110 and generate a signal that represents a temperature associated with an object external the temperature sensing device 100 (e.g., a human finger, ambient air temperature, etc.). In one implementation, the application-specific integrated circuit 154 may store calibration parameters to generate corresponding digital calculations.
The application-specific integrated circuit 154 may be configured to utilize a calibration protocol associated with the temperature sensing device 100. The application-specific integrated circuit 154 can compare the electrical signal that is common to both electrical signals to generate an electrical signal representing an error signal associated with the thermopile 110, the reference thermopile 150, the resistance temperature detector 152, the first temperature sensor 108, and/or the second temperature sensor 112. The application-specific integrated circuit 154 may then be calibrated for accurate temperature measurement based upon utilizing the error signal. This calibration protocol may be performed in-situ or during initial factory calibration.
In the process 200 illustrated, a substrate including a thermopile, a first temperature sensor, and a ceramic structure is received (Block 202). In some implementations, receiving a substrate 302 can include receiving a printed circuit board, for example, including a first temperature sensor 308 and a thermopile 310 both coupled to the printed circuit board using, for example, a die attach adhesive 334. In another implementation, receiving a substrate 102 can include receiving a substrate 102 can include receiving a substrate 102 including a thermopile 310 and a reference thermopile 150. Additionally, receiving the substrate 302 includes receiving a substrate 302 having a support structure 304 formed thereon. In implementations, the support structure 304 can be formed from a photodefinable (photo-structurable) glass previous to receiving the substrate 302. The substrate 302 can generally be configured to accept a lid assembly 336 in order to form a temperature sensing device 100.
Then, a lid assembly is placed on the support structure disposed on the substrate (Block 204). In implementations, placing a lid assembly 336 on the support structure 308 includes placing a lid assembly 336 where the lid assembly 336 includes at least one of a base layer 314, a first filter layer 116, a second filter layer 318, a first metal layer 320, a passivation layer 322, a second metal layer 326, at least one via 324, a metal plate 328, an epoxy ring 330, and/or a second temperature sensor 312 that is coupled with and/or integrated into the base layer 314 of the lid assembly 336. Placing the lid assembly 336 can include using pick-and-place and/or surface mount technologies and an adhesive, such as a die attach epoxy (e.g., epoxy ring 330), for example, to the top surface (e.g., the side distal from the substrate 302) of the support structure 304. When an epoxy ring 330 is included, it may serve as a hermetic seal for the cavity 106 and/or temperature sensing device 100. The lid assembly 336 may be placed such that an aperture 332 formed in the lid assembly 336 can be aligned with the thermopile 310 disposed on the substrate 302, but are not the reference thermopile 150 and/or first temperature sensor 308 and second temperature sensor 312. In implementations, placing the lid assembly 336 may form a cavity 306 at least partially defined by the lid assembly 336, the support structure 304, and the substrate 302. In embodiments, including the second temperature sensor 312 with the lid assembly 336 as well as in and/or exposed to the cavity 306 (or including a reference thermopile 150) allows a temperature gradient within the temperature sensing device 100 to be measured and compensated for when the temperature of an object is measured.
Although the subject matter has been described in language specific to structural features and/or process operations, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
Number | Date | Country | |
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62018092 | Jun 2014 | US |