MEMS temperature measurement structure and method

Abstract

This application provides a MEMS temperature measurement structure and method. The MEMS temperature measurement structure includes a support layer and a temperature sensing device. The support layer supports a resonator, and the temperature sensing device is disposed on the support layer and used to sense the average temperature of the support layer and the surface of the resonator. The temperature sensing device can sense the average temperature of the resonator during operation and balance the temperature gradient on the resonator surface, and can generate different resonant frequencies. The MEMS temperature measurement structure may also include a signal reading device, which surrounds the temperature sensing device and is used to read the temperature signal sensed by the temperature sensing device. When the resonant frequency of the temperature sensing device changes, the equivalent capacitance between the signal reading device and the temperature sensing device also changes accordingly. The dielectric constant of the dielectric material can be calculated based on the equivalent capacitance between the signal reading device and the temperature sensing device, and the temperature of the temperature sensing device can be calculated based on the dielectric constant to obtain the temperature of the resonator.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro-electro-mechanical system, and in particular to a MEMS temperature measurement structure and a temperature measurement method. BACKGROUND

[0002] Nowadays, clock source chips mainly play the functions of time synchronization, timing, wake-up, etc. in electronic devices. In recent years, with the wide application of wearable products such as TWS (True Wireless Stereo) earphones, smart watches, AR / VR (Augmented Reality / Virtual Reality), and the large-scale popularization of new energy vehicles, terminal products have put forward new requirements for the size, power consumption and anti-vibration performance of clock source chips. The clock chip based on the MEMS oscillator can obtain extremely small size, extremely low power consumption and extremely high anti-vibration performance because of adopting the full-silicon MEMS (Micro-Electro-Mechanical System) process, so it has attracted widespread attention in the industry.

[0003] However, compared with the traditional quartz oscillator, the frequency offset of the MEMS oscillator to temperature is still a problem to be solved. Due to the physical characteristics of single crystal silicon material, the frequency temperature coefficient of the MEMS oscillator can reach -31 ppm / ℃, that is, the frequency of oscillation changes by -0.003% when the temperature rises by 1 degree. Assuming that the temperature application range of the product is -40℃ to 85℃, the frequency drift is as high as 3750 ppm (parts per million), which is unacceptable for the application of most terminal systems today.

[0004] At present, the mainstream temperature sensors include CMOS (Complementary Metal Oxide Semiconductor) transistor temperature measurement sensors, thermistor temperature measurement sensors, thermal diffusion temperature measurement sensors, etc. Among them, the transistor temperature measurement and resistance temperature measurement can achieve good temperature measurement accuracy, but often there are problems of accuracy caused by photolithography error and thermal coupling factors, thereby causing the temperature test accuracy of the MEMS resonator to be poor, resulting in the output accuracy of the MEMS clock chip being limited.

[0005] Therefore, how to improve the temperature test accuracy of the MEMS resonator is one of the problems to be solved by those skilled in the art. SUMMARY

[0006] This application provides a MEMS temperature measurement structure and method to solve the problem that existing temperature sensors often have accuracy problems caused by photolithography errors and thermal coupling factors, resulting in poor temperature measurement accuracy of MEMS resonators and thus limiting the output accuracy of MEMS clock chips.

[0007] In a first aspect, embodiments of this application provide a MEMS temperature measurement structure, including:

[0008] A support layer is provided to support the resonator.

[0009] A temperature sensing device is disposed on the support layer and is used to sense the average temperature of the support layer and the surface of the resonator.

[0010] A signal reading device is provided, which is arranged around the temperature sensing device, and is used to read the temperature signal sensed by the temperature sensing device.

[0011] Optionally, in one embodiment, the temperature sensing device includes a dielectric material layer and a temperature sensing coil; the dielectric material layer is laid on the support layer to balance the surface temperature of the support layer and the resonator; the temperature sensing coil is attached to the dielectric material layer for temperature sensing.

[0012] Optionally, in one embodiment, the dielectric material layer is made of a material having high thermal conductivity and high dielectric constant.

[0013] Optionally, in one embodiment, the temperature sensing coil is a planar helical coil structure, and the temperature sensing coil is arranged circumferentially around the resonator.

[0014] Optionally, in one embodiment, the signal reading device is a planar helical coil structure, and the signal reading device is magnetically coupled to the temperature sensing device.

[0015] Optionally, in one embodiment, the MEMS temperature sensing structure further includes a cover that covers the support layer to encapsulate the resonator.

[0016] Optionally, in one embodiment, the MEMS temperature measurement structure further includes an IC chip, which is used to carry the support layer, the temperature sensing device, and the signal reading device, and the IC chip and the signal reading device are electrically connected.

[0017] Optionally, in one embodiment, the signal reading device is disposed on the surface of the IC chip; or,

[0018] The support layer includes a support top cover and a support bottom plate. The support top cover is placed on the support bottom plate to form an accommodating space. The temperature sensing device is disposed on the side of the support top cover away from the accommodating space. The signal reading device is disposed within the accommodating space and is arranged circumferentially around the resonator.

[0019] Secondly, embodiments of this application also provide a temperature measurement method applied to a MEMS temperature measurement structure as described in any of the above claims, the temperature measurement method comprising:

[0020] The average temperature of the support layer and the surface of the resonator is sensed by a temperature sensing device;

[0021] The resonant frequency of the temperature sensing device is sensed by a signal reading device;

[0022] The temperature of the resonator can be determined by the ratio of resonant frequency to temperature.

[0023] Optionally, in one embodiment, the operation of sensing the resonant frequency of the resonator through the signal reading device includes:

[0024] Read the port impedance and phase angle of the signal reading device to determine whether the temperature sensing device is resonating.

[0025] The MEMS temperature measurement structure provided in this application includes a support layer and a temperature sensing device. The support layer supports a resonator, and the temperature sensing device is disposed on the support layer and used to sense the average temperature of the support layer and the surface of the resonator. It is understood that the resonator operates at different temperatures under different conditions. The temperature sensing device can sense the average temperature of the resonator during operation and balance the temperature gradient on the resonator surface by sensing the average temperature of the support layer surface. Furthermore, it can generate different resonant frequencies based on the different average temperatures of the resonator.

[0026] Meanwhile, the MEMS temperature measurement structure can include a signal reading device, which surrounds the temperature sensing device and is used to read the temperature signal sensed by the temperature sensing device. When the resonant frequency of the temperature sensing device changes under different temperature conditions, the equivalent capacitance between the signal reading device and the temperature sensing device will also change accordingly. The dielectric constant of the dielectric material can be calculated based on the equivalent capacitance between the signal reading device and the temperature sensing device, and the temperature of the temperature sensing device can be calculated based on the dielectric constant to obtain the temperature of the resonator. This achieves accurate detection of the resonator temperature and avoids the accuracy problems of existing temperature sensors caused by photolithography errors and thermal coupling factors, which often result in poor temperature testing accuracy of MEMS resonators and limit the output accuracy of MEMS clock chips. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of the MEMS temperature measurement structure provided in the embodiments of this application.

[0029] Figure 2 for Figure 1 The diagram shows the structure of the MEMS temperature measurement structure hidden under the cover.

[0030] Figure 3 The equivalent circuit diagram of the temperature sensing coil and signal reading coil in the MEMS temperature measurement structure provided in the embodiments of this application is shown.

[0031] Figure 4 for Figure 2 The diagram shows an exploded view of the MEMS temperature measurement structure.

[0032] Figure 5 An exploded view of a MEMS temperature measurement structure provided in another embodiment of this application.

[0033] Figure 6 for Figure 1 The diagram shows the first cross-sectional structure of the MEMS temperature measurement structure along the LL direction.

[0034] Figure 7 for Figure 1 The diagram shows a second cross-sectional structure of the MEMS temperature measurement structure along the LL direction.

[0035] Figure 8 This is a schematic flowchart of the temperature measurement method provided in the embodiments of this application.

[0036] Figure 9 This is a schematic flowchart of a temperature measurement method provided in another embodiment of this application.

[0037] Figure label:

[0038] 100. MEMS temperature measurement structure; 110. Support layer; 111. Recessed area; 112. Flat area; 113. Supporting top cover; 114. Supporting bottom plate; 115. Accommodation space; 120. Resonator; 130. Temperature sensing device; 131. Dielectric material layer; 132. Temperature sensing coil; 140. Signal reading device; 150. Cover; 160. IC chip; 170. Encapsulation film. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0040] Currently, clock source chips primarily function in electronic devices for time synchronization, timing, and wake-up. In recent years, with the widespread application of wearable products such as TWS earphones, smartwatches, and AR / VR, as well as the large-scale popularization of new energy vehicles, terminal products have placed new demands on the size, power consumption, and vibration resistance of clock source chips. Clock chips based on MEMS oscillators, due to their use of all-silicon MEMS technology, can achieve extremely small size, extremely low power consumption, and extremely high vibration resistance, thus gaining widespread attention in the industry.

[0041] However, compared to traditional quartz oscillators, the frequency shift due to temperature remains a problem for MEMS oscillators. Due to the physical properties of single-crystal silicon, the frequency temperature coefficient of MEMS oscillators can reach -31 ppm / ℃, meaning that for every degree Celsius increase in temperature, the oscillation frequency changes by -0.003%. Assuming the product's operating temperature range is -40℃ to 85℃, the frequency drift would be as high as 3750 ppm, a frequency temperature coefficient that is unacceptable for most current end-system applications.

[0042] Currently, mainstream temperature sensors include CMOS transistor temperature sensors, thermistor temperature sensors, and thermal diffusion temperature sensors. Among them, transistor temperature measurement and resistance temperature measurement can achieve good temperature measurement accuracy. However, they often suffer from accuracy problems due to photolithography errors and thermal coupling factors, resulting in poor temperature measurement accuracy of MEMS resonators, which in turn limits the output accuracy of MEMS clock chips.

[0043] To address the aforementioned technical issues, this application provides a MEMS temperature measurement structure. Please refer to [link / reference]. Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the overall structure of the MEMS temperature measurement structure provided in the embodiments of this application. Figure 2 for Figure 1 The diagram shows the structure of the MEMS temperature measurement structure hidden under the cover.

[0044] like Figure 2As shown, in this embodiment, the MEMS temperature sensing structure 100 includes a support layer 110 and a temperature sensing device 130. The support layer 110 supports the resonator 120, and the temperature sensing device 130 is placed on the support layer 110 and used to sense the average temperature of the surfaces of the support layer 110 and the resonator 120. It can be understood that the temperature of the resonator 120 varies depending on its operating state. The temperature sensing device 130 can sense the average temperature of the resonator 120 during operation and balance the temperature gradient on the resonator surface by sensing the average temperature of the surfaces of the support layer 110 and the resonator 120. Simultaneously, the temperature sensing device 130 can also generate different resonant frequencies based on the average temperature of the resonator 120 under different operating conditions.

[0045] Meanwhile, the MEMS temperature measurement structure 100 may include a signal reading device 140, which surrounds the temperature sensing device 130. When the resonant frequency of the temperature sensing device 130 changes under different operating conditions of the resonator 120, the equivalent capacitance value between the signal reading device 140 and the temperature sensing device 130 will also change accordingly. The dielectric constant can be calculated based on the equivalent capacitance value between the signal reading device 140 and the temperature sensing device 130, and the temperature of the temperature sensing device 130 can be calculated based on the dielectric constant to obtain the temperature of the resonator 120. This achieves accurate detection of the temperature of the resonator 120, avoiding the accuracy problems of existing temperature sensors caused by photolithography errors and thermal coupling factors, which often result in poor temperature testing accuracy of the MEMS resonator 120 and limit the output accuracy of the MEMS clock chip.

[0046] Optional, please refer to Figure 2 In one embodiment, the support layer 110 may be provided with a recessed area 111, which is used to accommodate the resonator 120 and provide vibration space for the resonator 120 to protect the resonator 120 from interference from other components during operation vibration.

[0047] At the same time, please combine Figure 3 , Figure 3 This is an equivalent circuit diagram of the temperature sensing coil 132 and the signal reading coil in the MEMS temperature measurement structure provided in this application embodiment. Specifically, as shown... Figure 2 and Figure 3As shown, in this embodiment, the temperature sensing device 130 may include a dielectric material layer 131 and a temperature sensing coil 132. The dielectric material layer 131 and the temperature sensing coil 132 are used to balance the surface temperature of the support layer 110 and the resonator 120. The dielectric material layer 131 may be made of a material with high thermal conductivity and high dielectric constant, and the dielectric material layer 131 is laid on the support layer 110 to achieve the sensing effect of the average temperature emitted by the resonator 120 when it is working. The temperature sensing coil 132 is attached to the dielectric material layer 131, thereby forming a series or parallel resistor-capacitor-inductor network together with the dielectric material layer 131 to form a resonance peak at a specific frequency point. The resonance peak shifts with temperature changes (that is, when the temperature of the resonator 120 changes under different operating conditions, the resonant frequency of the temperature sensing coil 132 will change).

[0048] It should be noted that the dielectric material layer 131 in this embodiment can be one or more of aluminum nitride, aluminum oxide, and polyimide. It is also understood that the dielectric constant of the dielectric material layer 131, made of a material with high thermal conductivity and high dielectric constant, varies at different temperatures. The equivalent capacitance between the signal reading device 140 and the temperature sensing device 130 will also change accordingly. After calculating the dielectric constant of the dielectric material layer 131, made of a material with high thermal conductivity and high dielectric constant, based on the equivalent capacitance between the signal reading device 140 and the temperature sensing device 130, the corresponding temperature can be found. Since the temperature sensing device 130 is used to sense the temperature of the resonator 120, the temperature of the resonator 120 can be accurately determined based on the temperature of the thermally conductive dielectric material, avoiding the problem of large errors in resonator temperature measurement in the prior art.

[0049] Optional, please continue reading Figure 2 In one embodiment, the temperature sensing coil 132 is arranged around the circumference of the resonator 120, and the temperature sensing coil 132 can be a planar spiral coil structure. This can achieve comprehensive detection of the surface temperature of the dielectric material layer 131, thereby further improving the accuracy of temperature detection when the resonator 120 is working. It can also balance the temperature gradient between the resonator 120 and the surface of the dielectric material layer 131 as quickly as possible, achieving an average surface temperature of the dielectric material layer 131. This avoids the problem of inaccurate temperature measurement structure caused by uneven layout of the temperature sensing coil 132.

[0050] It is understood that, in other embodiments of this application, the support layer 110 may also be provided with, for example... Figure 2The flat area 112 shown, which surrounds the recessed area 111, can both support the temperature sensing coil 132 and prevent the temperature sensing coil 132 from contacting the resonator 120 during operation (at which time the resonator 120 is located in the recessed area 111), thus avoiding any situation that would affect the working performance of the resonator 120.

[0051] In addition, the signal reading device 140 can also be configured as follows: Figure 2 The planar spiral structure shown allows the signal reading device 140 to achieve magnetic coupling with the temperature sensing coil 132 by surrounding it, thereby increasing signal accuracy and ensuring high signal coupling strength between the signal reading device 140 and the temperature sensing coil 132. It is understood that the signal reading device 140 in this embodiment is made of conductive material, specifically copper or aluminum-nickel alloy, or a combination thereof.

[0052] Optional, such as Figure 1 As shown, in one embodiment, the MEMS temperature measurement structure 100 may include a cover 150, which covers the support layer 110 and is used to encapsulate the resonator 120. This not only protects the resonator 120 in operation, but also forms a vacuum structure to reduce air damping and improve the quality factor. In addition, the cover 150 can prevent the resonator 120 from contacting the outside air for heat exchange, thus avoiding the problem of inaccurate temperature measurement of the resonator 120 by the MEMS temperature measurement structure 100 in this embodiment.

[0053] In addition, please combine Figure 4 In one embodiment, the MEMS temperature measurement structure 100 may include an IC chip 160, which is used to support the support layer 110, the temperature sensing device 130, and the signal reading device 140, thereby preventing the support layer 110, the temperature sensing device 130, and the signal reading device 140 from being damaged due to contact with other components during operation. At the same time, in this embodiment, the signal reading device 140 may be laid on the surface of the IC chip 160, and the IC chip 160 may be electrically connected to the signal reading device 140.

[0054] Additionally, please see Figure 5 , Figure 5This is an exploded view of a MEMS temperature measurement structure provided in another embodiment of this application. In another embodiment, the support layer 110 includes a support top cover 113 and a support base plate 114. The support top cover 113 covers the support base plate 114 to form a receiving space 115. The temperature sensing device 130 is disposed on the side of the support top cover 113 away from the receiving space 115, while the signal reading device 140 can be disposed within the receiving space 115 and arranged circumferentially around the recessed area 111. This not only achieves the protection effect of the signal reading device 140, but also avoids interference from impurities in the external environment, thereby ensuring a more stable coupling connection between the temperature sensing device 130 and the signal reading device 140 located in the receiving space 115.

[0055] Optionally, please combine Figure 1 , Figure 4 and Figure 5 And see Figure 6 , Figure 6 for Figure 1 The diagram shows a schematic of the first cross-sectional structure of the MEMS temperature sensing structure along the LL direction. (See diagram for example.) Figure 6 As shown, in one embodiment, the support base plate 114 can be directly placed on the IC chip 160, and the support layer 110 and the IC chip 160 can be fixedly connected by the encapsulation film 170. In another embodiment, the support layer 110 can also be configured as follows: Figure 7 The inverted state shown means that the support base plate 114 is positioned away from the IC chip 160, and the support top cover 113 is positioned closer to the IC chip 160. It can be understood that, since this embodiment places the resonator 120 close to the IC chip 160, and the encapsulation film 170 achieves the encapsulation effect between the support top cover 113 and the IC chip 160, the accurate temperature measurement effect of the MEMS temperature measurement structure 100 in this embodiment is further guaranteed.

[0056] This application also provides a temperature measurement method applied to the aforementioned MEMS temperature measurement structure 100. For details, please refer to... Figure 8 , Figure 8 This is a schematic flowchart illustrating the temperature measurement method provided in this embodiment. The temperature measurement method provided in this embodiment includes:

[0057] 201: The average temperature of the surfaces of the support layer 110 and the resonator 120 is sensed by the temperature sensing device 130.

[0058] Specifically, when the temperature of the resonator 120 is different under different working conditions, the temperature sensing device 130 can accurately sense the average temperature of the resonator 120 during operation and balance the temperature gradient on the surface of the resonator by sensing the average surface temperature of the support layer 110 and the resonator 120. At the same time, the temperature sensing device 130 can also form different resonant frequencies according to the average temperature of the resonator 120 under different working conditions.

[0059] 202: The resonant frequency of the temperature sensing device 130 is sensed by the signal reading device 140.

[0060] Specifically, the signal reading device 140 is magnetically coupled to the temperature sensing device 130. When the resonant frequency of the temperature sensing device 130 changes under different operating conditions, the equivalent capacitance between the signal reading device 140 and the temperature sensing device 130 will also change according to the different resonant frequencies.

[0061] 203: The temperature of the resonator is determined based on the ratio of resonant frequency to temperature.

[0062] Specifically, the dielectric constant of the dielectric material can be calculated based on the equivalent capacitance between the signal reading device 140 and the temperature sensing device 130, and the average temperature of the temperature sensing device 130 can be calculated based on the dielectric constant to obtain the average temperature of the resonator 120. This achieves accurate detection of the average temperature of the resonator 120, avoiding the accuracy problems often caused by photolithography errors and thermal coupling factors in existing temperature sensors, which leads to poor temperature testing accuracy of the MEMS resonator 120 and limits the output accuracy of the MEMS clock chip.

[0063] Preferably, a series or parallel resistor-capacitor-inductor network (VRM) can be formed by setting a signal reading coil (i.e., signal reading device 140) and a temperature sensing coil 132. The VRM forms a resonant peak at a specific frequency point, and the resonant frequency value is proportional to the chip temperature. The chip temperature is read by exciting resonance through the magnetic coupling of the two coils, which reduces the interference of parasitic capacitance on the chip periphery to the signal. Compared with the existing frequency division phase-locked loop temperature measurement, the temperature measurement accuracy and temperature measurement resolution are higher.

[0064] Optional, please refer to Figure 9 , Figure 9 This is a schematic flowchart illustrating a temperature measurement method provided in another embodiment of this application. In another embodiment, the temperature measurement method includes:

[0065] 301: The average temperature of the surfaces of the support layer 110 and the resonator 120 is sensed by the temperature sensing device 130.

[0066] Specifically, when the temperature of the resonator 120 is different under different working conditions, the temperature sensing device 130 can accurately sense the average temperature of the resonator 120 during operation and balance the temperature gradient on the surface of the resonator by sensing the average surface temperature of the support layer 110 and the resonator 120. At the same time, the temperature sensing device 130 can also form different resonant frequencies according to the average temperature of the resonator 120 under different working conditions.

[0067] The operation of sensing the resonant frequency through the signal reading device 140 may include:

[0068] 302: Read the port impedance and phase angle of the signal reading device 140 to determine whether the sensing device is resonating.

[0069] For specific details, please refer to... Figure 3 In this context, R2 is the resistance of the signal reading device 140, L2 is the inductance of the signal reading device 140, R1 is the resistance of the temperature sensing device 130, L1 is the equivalent inductance of the temperature sensing device 130, C1 is the equivalent capacitance between the coil gaps, M is the mutual inductance between inductors L1 and L2, and k is the coupling coefficient.

[0070] More specifically, when only the signal reading device 140 is present, the port voltage of the signal reading device 140, according to Kirchhoff's voltage law, conforms to formula (1):

[0071] (1)

[0072] When the signal reading device 140 approaches the temperature sensing device 130, due to the magnetic coupling between the inductors, the port voltages of the signal reading device 140 and the temperature sensing device 130 are respectively:

[0073] (2)

[0074] (3)

[0075] (4)

[0076] Among them, capacitor The port voltage can be written as:

[0077] (5)

[0078] From formulas (1) to (5), it can be seen that when only the signal reading device 140 is present, the port impedance Z of the signal reading device 140 is... 10 for:

[0079] (6)

[0080] When the signal reading device 140 acts on the temperature sensing device 130, the port impedance of the signal reading device 140 becomes Z. 11 , can be represented as:

[0081] (7)

[0082] From the circuit schematic (i.e. Figure 3 As can be seen, the temperature sensing coil 132 and the underlying dielectric material layer 131 constitute an LRC resonant circuit, whose resonant frequency f0 and quality factor Q can be expressed as:

[0083] (8)

[0084] (9)

[0085] The port impedance Z of the signal reading device 140 can be obtained using formulas (7) to (9). 11 The real and imaginary parts and impedance Z 11 Phase:

[0086] (10)

[0087] (11)

[0088] (12)

[0089] (13)

[0090] From the port impedance Z 11 The magnitude and phase of the temperature sensor 130 are used to determine whether resonance occurs.

[0091] As an example, Z 11 With Z 10 At different times, the temperature sensing device 130 resonated; as another example, Z 11 When the phase angle changes, the temperature sensing device 130 resonates.

[0092] 303: The temperature of the resonator is determined based on the ratio of resonant frequency to temperature.

[0093] Specifically, the dielectric constant of the dielectric material can be calculated based on the equivalent capacitance between the signal reading device 140 and the temperature sensing device 130, and the average temperature of the temperature sensing device 130 can be calculated based on the dielectric constant to obtain the average temperature of the resonator 120. This achieves accurate detection of the average temperature of the resonator 120, avoiding the accuracy problems often caused by photolithography errors and thermal coupling factors in existing temperature sensors, which leads to poor temperature testing accuracy of the MEMS resonator 120 and limits the output accuracy of the MEMS clock chip.

[0094] Preferably, a series or parallel resistor-capacitor-inductor network (VRM) can be formed by setting a signal reading coil (i.e., signal reading device 140) and a temperature sensing coil 132. The VRM forms a resonant peak at a specific frequency point, and the resonant frequency value is proportional to the chip temperature. The chip temperature is read by exciting resonance through the magnetic coupling of the two coils, which reduces the interference of parasitic capacitance on the chip periphery to the signal. Compared with the existing frequency division phase-locked loop temperature measurement, the temperature measurement accuracy and temperature measurement resolution are higher.

[0095] The MEMS temperature measurement structure provided by this invention can average the temperature of the entire MEMS chip area by setting a dielectric material layer, balancing the temperature gradient on the chip surface, and reducing temperature measurement errors caused by thermal coupling. Furthermore, this invention can also form a series or parallel resistor-capacitor-inductor (VRM) network by setting a signal readout coil and a temperature sensing coil. The VRM forms a resonant peak at a specific frequency point, and the resonant frequency value is proportional to the chip temperature. Resonance is excited by magnetic coupling between the two coils to read the chip temperature, reducing the interference of parasitic capacitance on the signal from the chip's periphery. Compared with existing frequency division phase-locked loop temperature measurement, this invention offers higher temperature measurement accuracy and resolution. In addition, this invention sets the temperature sensing coil around the MEMS resonator, thereby obtaining average temperature information for a time-symmetric region; compared with existing transistor temperature measurement, the temperature measurement of this invention's MEMS temperature measurement structure is less affected by photolithography errors.

[0096] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0097] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0098] The MEMS temperature measurement structure and method provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A MEMS temperature sensing structure (100), characterized in that, include: A support layer (110) is used to carry the resonator (120). A temperature sensing device (130) is disposed on the support layer (110) and is used to sense the average temperature of the surface of the support layer (110) and the resonator (120); A signal reading device (140) is provided, which is arranged around the temperature sensing device (130) and is used to read the temperature signal sensed by the temperature sensing device (130). The temperature sensing device (130) includes a dielectric material layer (131) and a temperature sensing coil (132); the dielectric material layer (131) is laid on the support layer (110) to balance the surface temperature of the support layer (110) and the resonator (120); the temperature sensing coil (132) is attached to the dielectric material layer (131) for temperature sensing; The temperature sensing coil (132) is a planar spiral coil structure, and the temperature sensing coil (132) is arranged around the circumference of the resonator (120); The signal reading device (140) has a planar spiral coil structure, and the signal reading device (140) is magnetically coupled to the temperature sensing device (130); The support layer (110) is provided with a recessed area (111) for accommodating the resonator (120) and providing vibration space for the resonator (120). The support layer (110) is also provided with a flat area (112) surrounding the recessed area (111) and supporting the temperature sensing coil (132).

2. The MEMS temperature measurement structure (100) according to claim 1, characterized in that, The dielectric material layer (131) is made of a material with high thermal conductivity and high dielectric constant.

3. The MEMS temperature measurement structure (100) according to claim 1, characterized in that, The MEMS temperature measurement structure (100) also includes a cover (150) which covers the support layer (110) to encapsulate the resonator (120).

4. The MEMS temperature measurement structure (100) according to claim 1, characterized in that, The MEMS temperature measurement structure (100) also includes an IC chip (160), which is used to support the support layer (110), the temperature sensing device (130) and the signal reading device (140), and the IC chip (160) and the signal reading device (140) are electrically connected.

5. The MEMS temperature measurement structure (100) according to claim 4, characterized in that, The signal reading device (140) is disposed on the surface of the IC chip (160); or, The support layer (110) includes a support top cover (113) and a support bottom plate (114). The support top cover (113) covers the support bottom plate (114) to form a receiving space (115). The temperature sensing device (130) is disposed on the side of the support top cover (113) away from the receiving space (115). The signal reading device (140) is disposed in the receiving space (115) and is arranged around the resonator (120) circumferentially.

6. A temperature measurement method, applied to the MEMS temperature measurement structure (100) as described in any one of claims 1-5, wherein, The temperature measurement method includes: The average temperature of the surfaces of the support layer (110) and the resonator (120) is sensed by the temperature sensing device (130); The resonant frequency of the temperature sensing device (130) is sensed by the signal reading device (140); The temperature of the resonator (120) is determined based on the proportional relationship between the resonant frequency and the temperature. The step of determining the temperature of the resonator (120) based on the ratio of resonant frequency to temperature includes: The dielectric constant of the dielectric material layer (131) is calculated based on the equivalent capacitance between the signal reading device (140) and the temperature sensing device (130); The temperature of the resonator (120) is determined based on the dielectric constant.

7. The temperature measurement method according to claim 6, characterized in that, The operation of sensing the resonant frequency of the resonator (120) through the signal reading device (140) includes: Read the port impedance and phase angle of the signal reading device (140) to determine whether the temperature sensing device (130) is resonating.

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