Energy information integrated temperature sensor and preparation method

Abstract

The present invention discloses a temperature sensor integrating energy and information and a method for making the same. This method belongs to the field of micro-nano physical power supply technology and is characterized in that the method for making the temperature sensor integrating energy and information comprises at least the following steps: S1. preparing a thermoelectric device; S2. designing a thermoelectric power generation circuit comprising an ultra-low voltage DC / DC boost converter, a storage capacitor, and three outputs: a charging output, an LDO output, and a Vout output; S3. designing a cold-junction temperature compensation circuit; S4. designing a filter module and an AD conversion module within a controller; and S5. circuit assembly. The present invention utilizes the temperature sensitivity of the thermoelectric device's output voltage and its inherent power generation capabilities to design a power generation circuit and compensation circuit, thereby realizing an integrated energy and information temperature sensor.

Description

Technical Field

[0001] The present invention belongs to the technical field of micro-nano physical power supply, and in particular relates to an energy-information integrated temperature sensor and a preparation method thereof. Background Art

[0002] In recent years, there has been a surge in demand for miniature portable sensors in smart wearable systems, with the need for self-powered sensors with long battery life becoming increasingly urgent. Current portable sensors require a power supply, increasing design and cost. This paper proposes a self-powered temperature sensor that reduces energy consumption and increases battery life compared to traditional temperature sensors. Summary of the Invention

[0003] The present invention provides an energy-information integrated temperature sensor and a preparation method thereof, which can realize self-power supply, reduce energy consumption and increase battery life.

[0004] The first objective of the present invention is to provide a method for preparing a temperature sensor that integrates energy and information. By utilizing the temperature sensitivity of the output voltage of a thermoelectric device and its inherent power generation performance, a power generation circuit and a compensation circuit are designed to realize a temperature sensor that integrates energy and information. The preparation process is as follows:

[0005] 1. Prepare a temperature difference device; specifically:

[0006] (1) Drawings were drawn according to the device size and structure, and the hot and cold end Mo electrode layers with a thickness of 0.5 μm were prepared on a silicon dioxide substrate using magnetron sputtering and photolithography.

[0007] (2) The P and N element arrangement patterns are engraved on the surface of the electrode layer at the hot and cold ends respectively, and Au is deposited by vacuum evaporation with a thickness of 0.8 μm.

[0008] (3) The N and P element arrangement patterns are overlaid on the surfaces of the electrode layers at the hot and cold ends respectively, and a multi-target unbalanced magnetron sputtering process is used to prepare 150 μm thick thermoelectric P and N element micro-areas to form P and N type element arrays.

[0009] (4) On the surface of the prepared P and N elements, the Sn layer is again prepared by electron beam deposition method, and the thickness ratio of the Sn layer to the Au layer is 0.5 to 0.8.

[0010] (5) The exposed end faces of the P and N type components are placed opposite to the exposed electrode layer surfaces of the hot and cold ends, and the integration between the two is completed using the Au-Sn metal bonding process. The integration temperature is 240℃~360℃.

[0011] 2. Design the thermoelectric power generation circuit:

[0012] The output voltage of the thermoelectric device is low (less than 1V), so the LTC3108 ultra-low voltage DC / DC boost converter for thermoelectric power generation was selected. This boost topology can harvest energy from input voltages as low as 20mA. It outputs a 5V charging voltage to charge the energy storage capacitor, using a 2.2V LDO to power the processor. The main output can adjust to one of four fixed voltages (2.35V, 3.3V, 4.1V, and 5V), with 5V selected to power the op amp. The energy storage capacitor provides power to the processor and op amp when there is no input voltage source. This design ensures rapid charging of the output storage capacitor for a stable power supply.

[0013] 3. Design the cold junction compensation temperature circuit:

[0014] Since the cold end temperature is not 0℃, a compensation circuit is designed using compensation diodes, operational amplifiers and other devices to compensate the cold end potential to the potential at 0℃.

[0015] 4. Design a filtering module and an AD conversion module to convert the analog signal into temperature data. The temperature sensor prepared by the present invention has the characteristics of self-power supply and energy saving, realizing energy information integration.

[0016] 5. Circuit assembly; specifically:

[0017] Connect the input side of the ultra-low voltage DC / DC boost converter to the cold-end electrode layer and the hot-end electrode layer of the temperature difference device; connect the charging output of the ultra-low voltage DC / DC boost converter to the energy storage capacitor; connect the LDO output to the power receiving terminal of the processor; connect Vout to the power supply terminal of the operational amplifier; and connect the cold-end compensation temperature circuit to the cold-end electrode layer.

[0018] In the above preferred embodiment:

[0019] The thermoelectric device uses photolithography and sputtering processes to prepare the hot and cold end electrodes, and is integrated using metal bonding.

[0020] When the input voltage of the thermoelectric power generation circuit is ≥20mV, the circuit can work and collect energy.

[0021] The temperature difference power generation circuit can charge the energy storage capacitor with a maximum charging voltage of 5V.

[0022] The output of the thermoelectric power generation circuit includes a 2.2V LDO output.

[0023] The output of the temperature difference power generation circuit includes 4 adjustable power outputs, with voltages of 2.35v, 3.3v, 4.1v, and 5v respectively.

[0024] The cold-end compensation circuit selects appropriate compensation diodes and compensation multiples to perform potential compensation on the cold end of the temperature difference device.

[0025] The filtering part collects data of N cycles, removes the maximum and minimum values ​​in the N cycle data, and takes the average value of the remaining data.

[0026] The second object of the present invention is to provide a temperature sensor integrating energy and information, which is obtained by the above-mentioned preparation method.

[0027] The advantages and positive effects of the present invention are:

[0028] The present invention utilizes the characteristic of the sensor itself that it can generate electricity, designs a power generation circuit and a compensation circuit, so that the sensor itself can be self-powered, realizing energy and information integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A preparation flow chart of a preferred embodiment of the present invention;

[0030] Figure 2 is a circuit diagram of a power generation circuit in a preferred embodiment of the present invention;

[0031] Figure 3 is a circuit diagram of a compensation circuit in a preferred embodiment of the present invention;

[0032] Figure 4 FIG. 4 is a circuit diagram of a signal processing circuit in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings. The following embodiments are merely illustrative and not restrictive, and should not be used to limit the scope of protection of the present invention.

[0034] like Figures 1 to 4 As shown, the technical solution of the present invention is:

[0035] A method for fabricating an integrated energy and information temperature sensor involves fabricating hot and cold end electrodes using photolithography and sputtering processes, integrating them using metal bonding, and fabricating a thermoelectric device. The thermoelectric device has a low output voltage (<1V), so an ultra-low voltage DC / DC boost converter suitable for thermoelectric power generation is selected to power an external processor and load. A storage capacitor provides power when no input voltage source is present. This design ensures rapid charging of the output storage capacitor for stable power supply. Because the cold end temperature is not 0°C, a compensation circuit is designed. Because the cold end is in an environment with a non-0°C temperature, the potential at the cold end rises or falls from 0°C to a certain temperature. The voltage required for cold end compensation is calculated based on the diode temperature coefficient, thereby deriving the operational amplifier's amplification factor and designing the relevant parameters. A filtering module and A / D converter are designed to convert the analog signal into temperature data. Finally, a self-powered integrated energy and information temperature sensor is fabricated.

[0036] Example 1

[0037] 1. The preparation process of temperature difference device is as follows Figure 1 As shown:

[0038] (1) Drawings were drawn according to the device size and structure, and the hot and cold end Mo electrode layers with a thickness of 0.5 μm were prepared on a silicon dioxide substrate using magnetron sputtering and photolithography.

[0039] (2) The P and N element arrangement patterns are engraved on the surface of the electrode layer at the hot and cold ends respectively, and Au is deposited by vacuum evaporation with a thickness of 0.8 μm.

[0040] (3) The N and P element arrangement patterns are overlaid on the surfaces of the electrode layers at the hot and cold ends respectively, and a multi-target unbalanced magnetron sputtering process is used to prepare 150 μm thick thermoelectric P and N element micro-areas to form P and N type element arrays.

[0041] (4) On the surface of the prepared P and N elements, the Sn layer is again prepared by electron beam deposition method, and the thickness ratio of the Sn layer to the Au layer is 0.5 to 0.8.

[0042] (5) The exposed end faces of the P and N type components are placed opposite to the exposed electrode layer surfaces of the hot and cold ends, and the integration between the two is completed using the Au-Sn metal bonding process. The integration temperature is 240℃~360℃.

[0043] 2. Design the thermoelectric power generation circuit: The output voltage of the thermoelectric device is low (<1v), and the circuit schematic is as follows Figure 2 As shown, the LTC3108, an ultra-low voltage DC / DC boost converter for thermoelectric power generation, is selected. This boost topology can harvest energy from input voltages as low as 20mA. Vin_th+ is the positive output of the thermoelectric differential, and Vin_th- is the negative output. This topology outputs a 5V charging voltage to charge the energy storage capacitor. A 2.2V LDO is used to power the processor. The main output is connected to VAUS through VS1 / VS2, and is regulated to output 5V to power the op amp. The energy storage capacitor provides power when the input voltage source is absent. This design ensures rapid charging of the output storage capacitor for stable power supply.

[0044] 3. Design the cold junction compensation temperature circuit: the circuit schematic is as follows Figure 3As shown in the figure, since the cold junction temperature is not 0°C, an IN4148 is used as a compensation diode, and an LM321LV op amp is used to amplify the signal. A compensation circuit is designed. Since the ambient temperature rises from 0°C to 30°C, the thermocouple potential drops by 1.203mV. To obtain the correct value, 1.203mV must be subtracted from the negative terminal of the temperature difference. The diode's temperature coefficient is 2mV / °C. From 0°C to 30°C, the diode's terminal voltage changes by 60mV. However, only 1.203mV is required for compensation due to the temperature difference. 60mV / 1.203mV is 50 times smaller, reducing the diode's terminal voltage change to 1 / 50. The resistor divider, therefore, only requires (R4 + R5) / R5 = 50, resulting in the output signal through ADC_TEMP.

[0045] 4. Design the filter module and AD conversion to convert the analog signal into temperature data. The circuit schematic is as follows Figure 4 As shown, the GD32E230 is used as the processor. The filtering part collects data from 10 cycles, removes the maximum and minimum values ​​in the 10 cycles, and takes the average of the remaining data. The temperature sensor prepared by the present invention is self-powered and energy-saving, realizing energy information integration.

[0046] 5. Circuit assembly; specifically:

[0047] Connect the input side of the ultra-low voltage DC / DC boost converter to the cold-end electrode layer and the hot-end electrode layer of the temperature difference device; connect the charging output of the ultra-low voltage DC / DC boost converter to the energy storage capacitor; connect the LDO output to the power receiving terminal of the processor; connect Vout to the power supply terminal of the operational amplifier; and connect the cold-end compensation temperature circuit to the cold-end electrode layer.

[0048] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a temperature sensor integrating energy and information, characterized in that: At least: S1. Prepare a temperature difference device; specifically: S101, preparing a cold-end Mo electrode layer and a hot-end Mo electrode layer on a silicon dioxide substrate; S102, overlaying a P element arrangement pattern on the surface of the cold-end Mo electrode layer, overlaying an N element arrangement pattern on the surface of the hot-end Mo electrode layer, and depositing Au by vacuum evaporation; S103, overlaying a P element arrangement pattern on the surface of the cold-end Mo electrode layer, overlaying an N element arrangement pattern on the surface of the hot-end Mo electrode layer, and using a multi-target unbalanced magnetron sputtering process to prepare thermoelectric P element micro-regions and N element micro-regions to form a P-type element array and an N-type element array; S104, forming a Sn layer on the surface of the P-type element array and the N-type element array by electron beam deposition, wherein the thickness ratio of the Sn layer to the Au layer is 0.5 to 0.8; S105, placing the P-type element array opposite to the exposed electrode layer surface of the cold end, and placing the N-type element array opposite to the exposed electrode layer surface of the hot end, and integrating the two using an Au-Sn metal bonding process, with an integration temperature of 240° C. to 360° C.; S2. Design a thermoelectric power generation circuit including an ultra-low voltage DC / DC boost converter, energy storage capacitor, charging output, LDO output, and Vout output. S3. Design a cold junction temperature compensation circuit; the cold junction temperature compensation circuit uses IN4148 as a compensation diode and an operational amplifier LM321LV to amplify the signal; S4. Design a filtering module and an AD conversion module, using GD32E230 as a processor; the filtering module collects N cycles of data, removes the maximum and minimum values ​​in the N cycles of data, and takes the average value of the remaining data, where N is a natural number greater than 2; the AD conversion module converts the analog signal into temperature data; S5. Circuit assembly; specifically: Connect the input side of the ultra-low voltage DC / DC boost converter to the cold-end electrode layer and the hot-end electrode layer of the temperature difference device; connect the charging output of the ultra-low voltage DC / DC boost converter to the energy storage capacitor; connect the LDO output to the power receiving terminal of the processor; connect Vout to the power supply terminal of the operational amplifier LM321LV; and connect the cold-end compensation temperature circuit to the cold-end electrode layer.

2. The method for preparing the temperature sensor integrating energy and information according to claim 1, characterized in that: The S101 adopts a photolithography plus magnetron sputtering process, and the thickness of the cold-end Mo electrode layer and the hot-end Mo electrode layer are both 0.5 μm.

3. The method for preparing the temperature sensor integrating energy and information according to claim 1, characterized in that: In S102 , the thickness of Au is 0.8 μm.

4. The method for preparing the temperature sensor integrating energy and information according to claim 1, characterized in that: In S103 , the thickness of the P element micro region and the N element micro region are both 150 μm.

5. The method for preparing the temperature sensor integrating energy and information according to claim 1, characterized in that: The model of the ultra-low voltage DC / DC boost converter is LTC3108, the charging output voltage is 5V; the LDO output voltage is 2.2; the Vout output is one or more of 2.35V, 3.3V, 4.1V, and 5V.

6. A temperature sensor integrating energy and information, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 5.

7. The temperature sensor integrating energy and information according to claim 6, characterized in that: The output voltage of the temperature difference device is less than 1V.

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