Film temperature sensor array

Abstract

The invention discloses a thin film temperature sensor array, which adopts a flexible circuit board form, and is characterized in that a plurality of independent temperature sensor units are integrated on a thin film to form the sensor array; and comprehensive and omission-free temperature monitoring on the surface of the power lithium battery or the surfaces of other objects can be realized. Each sensor unit works independently and does not interfere with each other, so that the accuracy and comprehensiveness of monitoring are ensured; the sensor wires are tightly arranged, the wire width and the wire spacing are accurately controlled, the resistance value of each sensor unit is kept consistent under the same condition, and temperature measurement has high precision and stability by combining with a metal material with a positive temperature coefficient; through the alternate temperature measurement mode, the transistors for controlling the power supply of the sensor units are conducted in sequence, and only one sensor is measured at any moment, so that the current consumption in the measurement process is greatly reduced, and the service life is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of temperature measurement, in particular to a thin film temperature sensor array. Background Art

[0002] In some cases, it is necessary to conduct comprehensive and complete temperature monitoring on the surface of objects, such as the surface temperature measurement of power lithium batteries. When lithium batteries are charged or discharged at high currents, the internal resistance of the battery will generate heat when a large current passes through it. For example, when the battery is charged or discharged with a current of 100A, the internal resistance of the power battery is generally about 1 milliohm. At this time, the heat generated by a single battery is about 10 watts, but the number of batteries in the battery compartment of an electric vehicle is at least 100. Then, based on the number of 100 batteries, the total heat generated by the battery compartment with a charging current or discharge current of 100A will reach more than 1 kilowatt. The plane area of ​​the battery compartment generally does not exceed 2 square meters, and the height generally does not exceed 20 centimeters. In such a small space, a heat generation of 1 kilowatt will produce a rapid temperature rise, and it is easy to increase the temperature to more than 100 degrees. When the temperature of the ternary lithium battery exceeds 120 degrees, thermal decomposition will begin to occur. The thermal decomposition process is irreversible and thermal runaway will occur next, resulting in battery combustion and fire.

[0003] In order to prevent thermal runaway of lithium batteries in electric vehicles, it is necessary to monitor the temperature of lithium batteries in electric vehicles comprehensively, but there is currently no suitable means to monitor the temperature of lithium batteries. There are generally two methods for monitoring the temperature of lithium batteries in electric vehicles. One is to measure the temperature on the electrodes of the lithium batteries. For larger blade batteries, when heat is generated inside the blade batteries, the temperature inside the lithium batteries can hardly be measured at all on the electrodes of the lithium batteries. Another method for measuring the temperature of lithium batteries is to use a heat-conducting liquid to dissipate heat at the bottom of the lithium battery pack, and indirectly judge the temperature of the lithium battery by measuring the temperature of the heat-conducting liquid. This method can only measure the temperature at the bottom of the battery, and cannot reflect the temperature inside the lithium battery.

[0004] By the end of 2024, a technology has emerged that places temperature sensors inside lithium batteries for measurement. However, this temperature sensor can only measure the temperature of a certain point inside the lithium battery, and cannot measure the temperature rise in other parts of the lithium battery. The lithium dendrite reaction generated when the lithium battery is overcharged may occur anywhere inside the lithium battery. No matter how a single temperature sensor is installed, whether it is installed inside or outside the lithium battery, it is impossible to fully monitor the temperature of the lithium battery.

[0005] If the temperature generated by lithium batteries during charging and discharging cannot be monitored in time, when the temperature of the lithium batteries accumulates to the critical point of thermal runaway, electric vehicles will spontaneously combust. In 2023, an average of about 8 electric vehicles in my country spontaneously combusted every day.

[0006] Application number 202411545035.3 is a temperature sensing system for a transparent flexible circuit board, which uses transparent wires to connect temperature sensors. The sensor form is still a traditional single-point sensor, and cannot achieve large-area coverage without missing temperature measurements.

[0007] In addition, when a single planar temperature sensor has a large measurement area, temperature changes in a small area within the coverage area will have a smaller impact on the overall temperature sensor, which will also cause inaccurate measurements.

[0008] Therefore, there is an urgent need for a technology that can conduct comprehensive and comprehensive temperature monitoring of lithium batteries. When the temperature of the lithium battery rises to the warning temperature, it can issue a warning prompt to the system or personnel so that relevant measures can be taken to prevent the lithium battery temperature from further rising. Summary of the invention

[0009] In view of the problems existing in the prior art, the present invention discloses a thin film temperature sensor array. The technical solution adopted is that the thin film temperature sensor array is in the form of a flexible circuit board, and a sensor array is integrated internally. The thin film temperature sensor array at least includes a protective layer, a wiring layer, and a substrate layer. The wiring layer includes a temperature sensor array wiring. The sensor array may include one or more sensors. When there are multiple sensor arrays, the sensors are not connected to each other, and the resistance value of each sensor is the same.

[0010] As a preferred technical solution for a thin film temperature sensor array of the present invention, the shapes of the sensor routing may be different, but the total length of routing in different shapes or different areas remains the same to ensure that the resistance value of each sensor is the same; when there are multiple sensors, their routing is arranged in a "longitude and latitude" shape, and the total length of the routing between each sensor is the same.

[0011] As a preferred technical solution of a thin film temperature sensor array of the present invention, the sensor wiring is closely arranged, and the wiring width and line spacing are both 0.1 mm-0.2 mm, and the sensor resistance value reaches 50 ohms-200 ohms.

[0012] As a preferred technical solution of a thin film temperature sensor array of the present invention, when the number of the sensor array is 9-20, each sensor is measured through an analog-to-digital conversion port; when the number of analog-to-digital conversion ports is insufficient, a MOS tube is used as a switch to switch the sensor temperature to be measured to the analog-to-digital conversion port of the microcontroller.

[0013] As a preferred technical solution of a thin film temperature sensor array of the present invention, the sensor wiring is made of copper foil material or other metal material with a positive temperature coefficient, and the resistance value of the sensor unit changes with the temperature according to a predetermined temperature coefficient. The temperature calculation formula is: T = ((R1 / R0)-1) / α, where T is the current temperature value, R1 is the currently measured resistance value, R0 is the resistance value at the reference temperature of 0°C, and α is the temperature coefficient of resistivity.

[0014] As a preferred technical solution of a thin film temperature sensor array of the present invention, the current temperature is calculated by measuring the voltage divider value between the sensor unit and the standard resistor, and the calculation formula is: T = ((U1 / U0)-1) / α, where U1 is the voltage divider value between the current sensor unit and the standard resistor, U0 is the voltage divider value between the sensor unit and the standard resistor at the reference temperature, and α is the temperature coefficient of resistivity.

[0015] As a preferred technical solution of a thin film temperature sensor array of the present invention, the substrate layer is made of one or more of polyester film, polyimide, resin composite material, epoxy glass laminate, ceramic or metal substrate to ensure the reliability and flexibility of the circuit.

[0016] As a preferred technical solution of a thin film temperature sensor array of the present invention, it also includes a MOS tube switch array for controlling the power supply of each sensor unit, and a control circuit for allowing the function to be turned on during measurement, so as to realize the temperature measurement of the thin film temperature sensor array in turn, reduce the current consumption during the measurement process, and avoid the sensor unit from generating heat.

[0017] As a preferred technical solution of a thin film temperature sensor array of the present invention, the specific implementation method of the rotation temperature measurement is: turn on the transistors that control the power supply of the sensor units in sequence, and only one sensor is measured at any time, thereby realizing rotation temperature measurement of the thin film temperature sensor array.

[0018] As a preferred technical solution of a thin film temperature sensor array of the present invention, the thin film temperature sensor array is suitable for comprehensive and complete temperature monitoring of the surface of a power lithium battery, as well as other occasions requiring comprehensive temperature monitoring of the surface of an object.

[0019] Beneficial effects of the present invention: The present invention integrates multiple independent temperature sensor units on a thin film to form a sensor array, which can realize comprehensive and non-omission temperature monitoring of the surface of a power lithium battery or other object surface. Each sensor unit works independently and does not interfere with each other, ensuring the accuracy and comprehensiveness of monitoring; the sensor wiring is closely arranged, and the wiring width and line spacing are precisely controlled, so that the resistance value of each sensor unit remains consistent under the same conditions, combined with the metal material with a positive temperature coefficient, so that the temperature measurement has high accuracy and stability; through the temperature measurement method in turn, the transistors that control the power supply of the sensor unit are turned on in turn, and only one sensor is measured at any time, thereby greatly reducing the current consumption during the measurement process and extending the service life; the number of sensor arrays can be flexibly configured according to actual needs, and through the MOS tube switch array and the control circuit, the measurement of multiple sensor units in turn can be realized, so that the system has good scalability and adaptability; the substrate layer is made of high-performance materials, such as polyester film, polyimide, etc., to ensure the reliability and flexibility of the circuit, so that the thin film temperature sensor array can work stably in harsh environments and is suitable for various complex application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of a thin film temperature sensor array provided by an embodiment of the present invention;

[0021] Figure 2 The resistance values ​​of the unit resistors of the thin film temperature sensor array according to the embodiment of the present invention at different temperatures;

[0022] Figure 3 The temperature values ​​corresponding to the unit resistances of the thin film temperature sensor array according to the embodiment of the present invention when the resistances are different;

[0023] Figure 4 This is a circuit diagram of an embodiment of the present invention in which a matrix control access method is used to perform analog-to-digital conversion when the number of sensors is large. DETAILED DESCRIPTION

[0024] like Figure 1-Figure 4 Shown

[0025] Figure 1 In the embodiment, the thin film temperature sensor array divides the sensor into 9 temperature detection areas. Of course, it can also be designed into more areas, such as 20 temperature sensing arrays or other temperature detection areas. When there are more temperature sensing arrays, the microcontroller is required to perform too many scanning measurements.

[0026] Figure 2 The resistance value of the thin film temperature sensor unit is measured and calibrated at different temperatures. The resistance value is stored in the measured microcontroller. Only the current resistance value needs to be detected to compare and calculate the current temperature of the sensor.

[0027] Figure 3 This is the corresponding temperature coordinate diagram for different resistance values.

[0028] Figure 4 This is a measurement circuit diagram. Transistors Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, and Q9 are used to control the power supply of each unit in the thin film array sensor respectively. Transistor Q10 is used for the measurement permission function. When Q10 is disconnected, the sensor unit does not consume circuit. Only when measuring, Q10 is turned on. This can greatly reduce the current consumed during the measurement process and avoid the sensor from generating heat.

[0029] Resistor R1 divides the power supply V+ and then powers the sensor. When measuring, first turn on transistor Q10 and then turn on transistor Q1. In this way, the first sensor unit is powered and a voltage drop is generated through resistor R1. The voltage is sent to the microcontroller for analog-to-digital conversion to calculate the current voltage value. By comparing the current voltage value with the stored voltage value data of the sensor at different temperatures, the current temperature value of the sensor can be calculated.

[0030] Example 1

[0031] The present invention discloses a thin film temperature sensor array, which adopts the form of a flexible circuit board and integrates a sensor array internally. The thin film temperature sensor array at least comprises a protective layer, a routing layer, and a substrate layer. The substrate layer is made of one or more of polyester film, polyimide, resin composite material, epoxy glass laminate, ceramic or metal substrate to ensure the reliability and flexibility of the circuit. The routing layer comprises temperature sensor array routing. The sensor array may include one or more sensors. When there are multiple sensor arrays, the sensors are not interconnected, and the resistance value of each sensor is the same. The shapes of the sensor routing may be different, but the total length of the routing in different shapes or different areas remains the same to ensure the same resistance value of each sensor. When there are multiple sensors, the routing is arranged in a "longitude and latitude" shape, and the total length of the routing between each sensor is the same. The sensor routing is a closely arranged routing, and the routing width and line spacing are both 0.1 mm, and the sensor resistance value reaches 50 ohms.

[0032] The number of the sensor array is 9, and each sensor is measured through an analog-to-digital conversion port; when the number of analog-to-digital conversion ports is insufficient, the MOS tube is used as a switch to switch the sensor temperature to be measured to the analog-to-digital conversion port of the single-chip microcomputer; it also includes a MOS tube switch array for controlling the power supply of each sensor unit, and a control circuit for allowing the function to be turned on during measurement, so as to realize the temperature measurement of the thin film temperature sensor array in turn, reduce the current consumption during the measurement process, and avoid the sensor unit from generating heat; the specific implementation method of the said rotating temperature measurement is: turn on the transistors that control the power supply of the sensor unit in turn, and only one sensor is measured at any time, so as to realize the temperature measurement of the thin film temperature sensor array in turn.

[0033] The sensor wiring is made of copper foil material or other metal material with a positive temperature coefficient, and the resistance value of the sensor unit changes with the temperature according to a predetermined temperature coefficient. The temperature calculation formula is: T = ((R1 / R0)-1) / α, where T is the current temperature value, R1 is the currently measured resistance value, R0 is the resistance value at the reference temperature of 0°C, and α is the temperature coefficient of resistivity.

[0034] The current temperature is calculated by measuring the voltage divider between the sensor unit and the standard resistor. The calculation formula is: T = ((U1 / U0)–1) / α, where U1 is the voltage divider between the current sensor unit and the standard resistor, U0 is the voltage divider between the sensor unit and the standard resistor at the reference temperature, and α is the temperature coefficient of resistivity.

[0035] The thin film temperature sensor array is suitable for comprehensive and complete temperature monitoring of the surface of a power lithium battery, as well as other occasions where comprehensive temperature monitoring of the surface of an object is required.

[0036] Example 2

[0037] The present invention discloses a thin film temperature sensor array, which adopts the form of a flexible circuit board and integrates a sensor array internally. The thin film temperature sensor array at least comprises a protective layer, a routing layer, and a substrate layer. The substrate layer is made of one or more of polyester film, polyimide, resin composite material, epoxy glass laminate, ceramic or metal substrate to ensure the reliability and flexibility of the circuit. The routing layer comprises temperature sensor array routing. The sensor array may include one or more sensors. When there are multiple sensor arrays, the sensors are not interconnected, and the resistance value of each sensor is the same. The shapes of the sensor routing may be different, but the total length of the routing in different shapes or different areas remains the same to ensure the same resistance value of each sensor. When there are multiple sensors, the routing is arranged in a "longitude and latitude" shape, and the total length of the routing between each sensor is the same. The sensor routing is a closely arranged routing, and the routing width and line spacing are both 0.15 mm, and the sensor resistance value reaches 120 ohms.

[0038] When the number of the sensor array is 16, each sensor is measured through an analog-to-digital conversion port; when the number of analog-to-digital conversion ports is insufficient, the MOS tube is used as a switch to switch the sensor temperature to be measured to the analog-to-digital conversion port of the single-chip microcomputer; it also includes a MOS tube switch array for controlling the power supply of each sensor unit, and a control circuit for allowing the function to be turned on during measurement, so as to realize the temperature measurement of the thin film temperature sensor array in turn, reduce the current consumption during the measurement process, and avoid the sensor unit from generating heat; the specific implementation method of the temperature measurement in turn is: turn on the transistors that control the power supply of the sensor unit in turn, and only one sensor is measured at any time, so as to realize the temperature measurement of the thin film temperature sensor array in turn.

[0039] The sensor wiring is made of copper foil material or other metal material with a positive temperature coefficient, and the resistance value of the sensor unit changes with the temperature according to a predetermined temperature coefficient. The temperature calculation formula is: T = ((R1 / R0)-1) / α, where T is the current temperature value, R1 is the currently measured resistance value, R0 is the resistance value at the reference temperature of 0°C, and α is the temperature coefficient of resistivity.

[0040] The current temperature is calculated by measuring the voltage divider between the sensor unit and the standard resistor. The calculation formula is: T = ((U1 / U0)–1) / α, where U1 is the voltage divider between the current sensor unit and the standard resistor, U0 is the voltage divider between the sensor unit and the standard resistor at the reference temperature, and α is the temperature coefficient of resistivity.

[0041] The thin film temperature sensor array is suitable for comprehensive and complete temperature monitoring of the surface of a power lithium battery, as well as other occasions where comprehensive temperature monitoring of the surface of an object is required.

[0042] Example 3

[0043] The present invention discloses a thin film temperature sensor array, which adopts the form of a flexible circuit board and integrates a sensor array internally. The thin film temperature sensor array at least comprises a protective layer, a routing layer, and a substrate layer. The substrate layer is made of one or more of polyester film, polyimide, resin composite material, epoxy glass laminate, ceramic or metal substrate to ensure the reliability and flexibility of the circuit. The routing layer comprises temperature sensor array routing. The sensor array may include one or more sensors. When there are multiple sensor arrays, the sensors are not connected to each other, and the resistance value of each sensor is the same. The shapes of the sensor routing may be different, but the total length of the routing in different shapes or different areas remains the same to ensure the same resistance value of each sensor. When there are multiple sensors, the routing is arranged in a "longitude and latitude" shape, and the total length of the routing between each sensor is the same. The sensor routing is a closely arranged routing, and the routing width and line spacing are both 0.2 mm, and the sensor resistance value reaches 200 ohms.

[0044] When the number of the sensor array is 20, each sensor is measured through an analog-to-digital conversion port; when the number of analog-to-digital conversion ports is insufficient, the MOS tube is used as a switch to switch the sensor temperature to be measured to the analog-to-digital conversion port of the single-chip microcomputer; it also includes a MOS tube switch array for controlling the power supply of each sensor unit, and a control circuit for allowing the function to be turned on during measurement, so as to realize the temperature measurement of the thin film temperature sensor array in turn, reduce the current consumption during the measurement process, and avoid the sensor unit from generating heat; the specific implementation method of the temperature measurement in turn is: turn on the transistors that control the power supply of the sensor unit in turn, and only one sensor is measured at any time, so as to realize the temperature measurement of the thin film temperature sensor array in turn.

[0045] The sensor wiring is made of copper foil material or other metal material with a positive temperature coefficient, and the resistance value of the sensor unit changes with the temperature according to a predetermined temperature coefficient. The temperature calculation formula is: T = ((R1 / R0)-1) / α, where T is the current temperature value, R1 is the currently measured resistance value, R0 is the resistance value at the reference temperature of 0°C, and α is the temperature coefficient of resistivity.

[0046] The current temperature is calculated by measuring the voltage divider between the sensor unit and the standard resistor. The calculation formula is: T = ((U1 / U0)–1) / α, where U1 is the voltage divider between the current sensor unit and the standard resistor, U0 is the voltage divider between the sensor unit and the standard resistor at the reference temperature, and α is the temperature coefficient of resistivity.

[0047] The thin film temperature sensor array is suitable for comprehensive and complete temperature monitoring of the surface of a power lithium battery, as well as other occasions where comprehensive temperature monitoring of the surface of an object is required.

[0049] The circuit connection involved in the present invention is a common method used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments, and it belongs to the widely used existing technology.

[0050] Components not described in detail herein are prior art.

[0051] Although the specific embodiments of the present invention are described in detail above, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in this field without departing from the purpose of the present invention, and modifications or deformations without creative labor are still within the protection scope of the present invention.

Claims

1. A thin film temperature sensor array, characterized in that: The thin film temperature sensor array is in the form of a flexible circuit board with an integrated sensor array inside. The thin film temperature sensor array includes at least a protective layer, a wiring layer, and a substrate layer. The wiring layer includes temperature sensor array wiring. The sensor array may include one or more sensors. When there are multiple sensor arrays, the sensors are not interconnected, and the resistance value of each sensor is the same.

2. The thin film temperature sensor array according to claim 1, characterized in that: The shapes of the sensor routing lines may be different, but the total length of routing lines in different shapes or different areas remains the same to ensure that the resistance value of each sensor is the same; when there are multiple sensors, their routing lines are arranged in a "longitude and latitude" shape, and the total length of routing lines between each sensor is the same.

3. The thin film temperature sensor array according to claim 1 or 2, characterized in that: The sensor wiring is closely arranged, and the wiring width and line spacing are both 0.1 mm-0.2 mm, and the sensor resistance value reaches 50 ohms-200 ohms.

4. The thin film temperature sensor array according to claim 1, characterized in that: When the number of the sensor array is 9-20, each sensor is measured through an analog-to-digital conversion port; when the number of analog-to-digital conversion ports is insufficient, the MOS tube is used as a switch to switch the sensor temperature to be measured to the analog-to-digital conversion port of the microcontroller.

5. The thin film temperature sensor array according to claim 1, characterized in that: The sensor wiring is made of copper foil material or other metal material with a positive temperature coefficient, and the resistance value of the sensor unit changes with the temperature according to a predetermined temperature coefficient. The temperature calculation formula is: T = ((R1 / R0)-1) / α, where T is the current temperature value, R1 is the currently measured resistance value, R0 is the resistance value at the reference temperature of 0°C, and α is the temperature coefficient of resistivity.

6. The thin film temperature sensor array according to claim 1, characterized in that: The current temperature is calculated by measuring the voltage divider between the sensor unit and the standard resistor. The calculation formula is: T = ((U1 / U0)–1) / α, where U1 is the voltage divider between the current sensor unit and the standard resistor, U0 is the voltage divider between the sensor unit and the standard resistor at the reference temperature, and α is the temperature coefficient of resistivity.

7. The thin film temperature sensor array according to claim 1, characterized in that: The substrate layer is made of one or more of polyester film, polyimide, resin composite material, epoxy glass laminate, ceramic or metal substrate to ensure the reliability and flexibility of the circuit.

8. The thin film temperature sensor array according to claim 4, characterized in that: It also includes a MOS tube switch array for controlling the power supply of each sensor unit, and a control circuit for allowing functions to be turned on during measurement, so as to realize temperature measurement of the thin film temperature sensor array in turn, reduce current consumption during the measurement process, and avoid heat generation in the sensor unit.

9. The thin film temperature sensor array according to claim 8, characterized in that: The specific implementation method of the rotation temperature measurement is: turn on the transistors that control the power supply of the sensor units in sequence, and only one sensor is measured at any time, so as to realize the rotation temperature measurement of the thin film temperature sensor array.

10. The thin film temperature sensor array according to any one of claims 1 to 9, characterized in that: The thin film temperature sensor array is suitable for comprehensive and complete temperature monitoring of the surface of a power lithium battery, as well as other occasions where comprehensive temperature monitoring of the surface of an object is required.

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