Temperature determining device, temperature determining method, and micro-electro-mechanical system oscillator

Abstract

This application discloses a temperature determination device, a temperature determination method, and a microelectromechanical system (MEMS) oscillator. The temperature determination device includes: a first capacitor for outputting a first capacitance value; a second capacitor for outputting a second capacitance value; a coupling unit electrically connected to both the first and second capacitors for coupling the first and second capacitance values ​​to obtain a corresponding coupling value; and a temperature determination unit electrically connected to the coupling unit for determining the temperature of the MEMS oscillator using the coupling value. Through this method, the temperature of the MEMS oscillator can be measured relatively accurately.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro-electro-mechanical system (MEMS) oscillators, and in particular to a temperature determination device, a temperature determination method, and a MEMS oscillator. BACKGROUND

[0002] Temperature-induced measurement difference is one of the major challenges faced by MEMS oscillators. Existing ways to reduce the impact of temperature on MEMS oscillators can be divided into two categories, namely passive compensation or active compensation.

[0003] Passive compensation includes using materials with different temperature coefficients to manufacture MEMS oscillators, and using different doping materials or different doping concentrations to reduce temperature dependence. Active compensation includes applying a controlled voltage to the MEMS oscillator according to the current temperature to change the physical properties in the structure of the MEMS oscillator, and ultimately compensate for the resonant frequency of the MEMS oscillator. Although active compensation can achieve a wider temperature compensation range, it requires high-precision temperature measurement. SUMMARY

[0004] The present application provides a temperature determination device, a temperature determination method, and a MEMS oscillator, which can accurately measure the temperature of the MEMS oscillator.

[0005] To solve the above technical problems, one technical solution adopted by the present application is to provide a temperature determination device, which is applied to a MEMS oscillator, and includes: a first capacitor configured to output a first capacitance value; a second capacitor configured to output a second capacitance value; a coupling unit electrically connected to the first capacitor and the second capacitor respectively, configured to couple the first capacitance value and the second capacitance value to obtain a corresponding coupling value, wherein the coupling value is proportional to the temperature of the MEMS oscillator; and a temperature determination unit electrically connected to the coupling unit, configured to determine the temperature of the MEMS oscillator by using the coupling value.

[0006] The coupling unit is configured to subtract the first capacitance value from the second capacitance value to obtain the corresponding coupling value.

[0007] The coupling unit is configured to use the ratio between the second capacitance value and the first capacitance value as the coupling value.

[0008] The coupling unit is configured to determine the capacitance sum of the second capacitance value and the first capacitance value, and use the ratio between the second capacitance value and the capacitance sum as the coupling value.

[0009] The first capacitor and the second capacitor are MEMS capacitors.

[0010] The first capacitance value of the first capacitor is negatively related to temperature, and the second capacitance value of the second capacitor is positively related to temperature.

[0011] To solve the above technical problems, another technical solution adopted by the present application is to provide a micro-electro-mechanical system oscillator, comprising: a MEMS die; a CMOS die, electrically coupled with the MEMS die; wherein the micro-electro-mechanical system oscillator is provided with a temperature determination device as described in the above technical solution.

[0012] The first capacitor and the second capacitor are commonly arranged on the MEMS die or the CMOS die; or one of the first capacitor and the second capacitor is arranged on the MEMS die, and the other is arranged on the CMOS die.

[0013] The coupling unit and the temperature determination unit are arranged on the CMOS die.

[0014] To solve the above technical problems, another technical solution adopted by the present application is to provide a temperature determination method, which is applied to a micro-electro-mechanical system oscillator, and the temperature determination method comprises: obtaining a first capacitance value of a first capacitor; and obtaining a second capacitance value of a second capacitor; coupling the first capacitance value and the second capacitance value to obtain a corresponding coupling value, wherein the coupling value is proportional to the temperature of the micro-electro-mechanical system oscillator; and determining the temperature of the micro-electro-mechanical system oscillator by using the coupling value.

[0015] The present application has the beneficial effect that, different from the prior art, the temperature determination device of the present application utilizes the proportional relationship between the capacitance value of the capacitor and the temperature, and determines the temperature of the micro-electro-mechanical system oscillator by using the corresponding coupling value of the two capacitors, so that the temperature of the micro-electro-mechanical system oscillator can be measured more accurately. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort, based on these drawings. Among them:

[0017] Figure 1 is a structural schematic diagram of a first embodiment of the temperature determination device provided by the present application;

[0018] Figure 2 is a corresponding relationship diagram of the first capacitor, the second capacitor and temperature provided by the present application;

[0019] Figure 3 is a corresponding relationship diagram of the coupling value and temperature provided by the present application;

[0020] Figure 4 is another correspondence between coupling value and temperature provided by the present application;

[0021] Figure 5 is a structure diagram of a first capacitor according to an embodiment of the present application;

[0022] Figure 6 is a structure diagram of a second capacitor according to an embodiment of the present application;

[0023] Figure 7 is a structure diagram of a temperature determining device according to a second embodiment of the present application;

[0024] Figure 8 is a structure diagram of a micro-electro-mechanical system oscillator according to an embodiment of the present application;

[0025] Figure 9 is a flow diagram of a temperature determining method according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative work, fall within the scope of protection of the present application.

[0027] The terms "first", "second", and the like in the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include other steps or units not listed or can optionally include other steps or units inherent to the process, method, product or device.

[0028] In this document, reference to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be combined with any of the other embodiments.

[0029] Reference is made to Figure 1 , Figure 1is a structural schematic diagram of a first embodiment of the temperature determination apparatus provided in the present application. The temperature determination apparatus 1 comprises a first capacitor 11, a second capacitor 12, a coupling unit 13 and a temperature determination unit 14.

[0030] The first capacitor 11 is configured to output a first capacitance value C1.

[0031] The second capacitor 12 is configured to output a second capacitance value C2.

[0032] In some embodiments, referring to Figure 2 The first capacitance value C1 of the first capacitor 11 is negatively correlated with temperature, i.e., the first capacitance value C1 of the first capacitor 11 decreases as the temperature increases.

[0033] The second capacitance value C2 of the second capacitor 12 is positively correlated with temperature, i.e., the second capacitance value C2 of the second capacitor 12 increases as the temperature increases.

[0034] In some embodiments, the first capacitor 11 and the second capacitor 12 can be MEMS capacitors.

[0035] The coupling unit 13 is electrically connected to the first capacitor 11 and the second capacitor 12 respectively, and is configured to couple the first capacitance value C1 and the second capacitance value C2 to obtain a corresponding coupling value. The coupling value is proportional to the temperature of the micro-electro-mechanical system oscillator.

[0036] The coupling unit 13 determines the coupling value in any of the following ways:

[0037] The first way: during the coupling of the coupling unit 13, the coupling unit 13 is configured to subtract the first capacitance value C1 from the second capacitance value C2 to obtain the corresponding coupling value. That is, the coupling value = C2-C1. The schematic diagram of the coupling value can be referred to Figure 3 .

[0038] The second way: during the coupling of the coupling unit 13, the coupling unit 13 is configured to use the ratio between the second capacitance value C2 and the first capacitance value C1 as the coupling value. That is, the coupling value = C2 / C1. The schematic diagram of the coupling value can be referred to Figure 4 .

[0039] The third way: during the coupling of the coupling unit 13, the coupling unit 13 is configured to determine the capacitance sum of the second capacitance value C2 and the first capacitance value C1, and use the ratio between the second capacitance value C2 and the capacitance sum as the coupling value. That is, the coupling value = C2 / (C1+C2).

[0040] The temperature determination unit 14 is electrically connected to the coupling unit 13, and is configured to determine the temperature of the micro-electro-mechanical system oscillator by using the coupling value.

[0041] The temperature determining unit 14 is electrically connected to the coupling unit 13 to receive the coupling value, and determines the temperature based on the coupling value.

[0042] In some embodiments, the first capacitor 11 and the second capacitor 12 are MEMS capacitors, and have different structures. As the temperature rises, the first capacitor 11 expands thermally, causing the first capacitance C1 to decrease, and the second capacitor 12 expands thermally, causing the second capacitance C2 to increase. The first capacitor 11 and the second capacitor 12 can be arranged in the MEMS oscillator 2.

[0043] Further, in combination with Figure 5 the corresponding relationship between the first capacitor 11 and the temperature is introduced.

[0044] As shown in Figure 5 , the first capacitor 11 includes a first anchor electrode 111 and a second anchor electrode 112. The first anchor electrode 111 includes a first electrode 1112 and a plurality of second electrodes 1111. The plurality of second electrodes 1111 are arranged at one side of the first electrode 1112.

[0045] The second anchor electrode 112 includes a third electrode 1122 and a plurality of fourth electrodes 1121. The plurality of fourth electrodes 1121 are arranged at one side of the third electrode 1122.

[0046] Specifically, the first electrode 1112 and the third electrode 1122 are arranged at intervals, and the plurality of second electrodes 1111 and the plurality of fourth electrodes 1121 are arranged at intervals and cross each other in the interval region between the first electrode 1112 and the third electrode 1122. The first electrode 1112 is arranged close to the first anchor electrode 111, and the third electrode 1122 is arranged close to the second anchor electrode 112.

[0047] Therefore, as the temperature rises, the first anchor electrode 111 and the second anchor electrode 112 will move in the thermal expansion direction according to Figure 5 .

[0048] Based on the capacitance formula c = εs / 4πkd, where: ε: dielectric permittivity (relative permittivity) k: electrostatic force constant, S: facing area of two plates, d: vertical distance between two plates.

[0049] As the first anchor electrode 111 and the second anchor electrode 112 move in the thermal expansion direction according to Figure 5 , the facing area between the second electrode 1111 and the fourth electrode 1121 arranged at intervals and cross each other decreases, so the capacitance of the first capacitor 11 decreases.

[0050] In combination with Figure 6 the corresponding relationship between the second capacitor 12 and the temperature is introduced.

[0051] like Figure 6 As shown, the second capacitor 12 includes a third anchoring electrode 121 and a fourth anchoring electrode 122. The third anchoring electrode 121 includes a fifth electrode 1212 and a plurality of sixth electrodes 1211. The plurality of sixth electrodes 1211 are spaced apart on one side of the fifth electrode 1212.

[0052] The fourth anchoring electrode 122 includes a seventh electrode 1222 and a plurality of eighth electrodes 1221. The plurality of eighth electrodes 1221 are spaced apart on one side of the seventh electrode 1222.

[0053] Specifically, the fifth electrode 1212 and the seventh electrode 1222 are arranged alternately, and a plurality of sixth electrodes 1211 and eighth electrodes 1221 are arranged alternately and intermittently in the interval region between the fifth electrode 1212 and the seventh electrode 1222. Among them, the fifth electrode 1212 is arranged close to the fourth anchoring electrode 122, and the seventh electrode 1222 is arranged close to the third anchoring electrode 121.

[0054] Therefore, as the temperature rises, the third anchoring electrode 121 and the fourth anchoring electrode 122 will... Figure 6 The direction of thermal expansion shifts.

[0055] Based on the capacitance formula c=εs / 4πkd, where: ε: dielectric constant of the medium (relative dielectric constant), k: electrostatic constant, S: area of ​​the two plates facing each other, and d: vertical distance between the two plates.

[0056] As the third anchoring electrode 121 and the fourth anchoring electrode 122 will follow Figure 6 As the thermal expansion direction shifts, the area between the sixth electrode 1211 and the eighth electrode 1221, which are arranged at an alternating interval, increases, thus increasing the capacitance of the second capacitor 12.

[0057] Specifically, the coupling value is proportional to the temperature. The temperature determination unit 14 pre-stores the correspondence between the coupling value and the temperature. The temperature determination unit 14 receives the coupling value from the coupling unit 13 and determines the current temperature based on this correspondence. The correspondence between the coupling value and the temperature can be obtained from empirical data. For example, the device can be placed in a space with a determinable temperature and the temperature can be gradually adjusted to obtain multiple sets of first capacitor values ​​C1 and second capacitor values ​​C2. The coupling values ​​are then obtained, and the temperatures corresponding to each coupling value are recorded to obtain the correspondence between the coupling value and the temperature. Alternatively, the temperature coefficients of the first capacitor 11 and the second capacitor 12 can be used to obtain the correspondence between the coupling value and the temperature through a polynomial fitting calculation circuit. However, the embodiments of this application are not limited to these methods. The temperature determination unit 14 can also obtain the temperature value corresponding to the coupling value through fitting calculation after receiving the coupling value. The relevant values ​​used by the temperature determination unit 14 for fitting calculation can be preset. For example, the temperature determining device 1 is placed in a space where the temperature can be determined and the temperature is gradually adjusted to obtain multiple sets of first capacitance values ​​C1 and second capacitance values ​​C2. The coupling values ​​are obtained by coupling, and the temperature corresponding to each coupling value is recorded. The relevant values ​​used for fitting calculation by the temperature determining unit 14 are obtained by performing polynomial curve fitting through multiple sets of corresponding coupling values ​​and temperatures.

[0058] In the above embodiment, the temperature determination device 1 utilizes the proportional relationship between the capacitance value of the capacitor and the temperature, and uses the coupling value corresponding to the two capacitors to determine the temperature of the microelectromechanical system oscillator 2. Thus, the temperature of the microelectromechanical system oscillator 2 can be measured more accurately.

[0059] Furthermore, in other embodiments, see [reference] Figure 7 To facilitate the subsequent use of this temperature, the temperature determination device 1 also includes an output unit 15, which is electrically connected to the temperature determination unit 14 to obtain and output temperature data from the temperature determination unit 14.

[0060] The temperature determination device 1 of this application can be used to measure the temperature of a microelectromechanical system (MEMS) oscillator 2. For accurate measurement, the temperature determination device 1 can be arranged inside the MEMS oscillator 2. In this case, the first capacitor 11 and the second capacitor 12 can be MEMS capacitors, fabricated using MEMS technology.

[0061] However, this application is not limited to this. The temperature determination device 1 can be connected to the microelectromechanical system oscillator 2 as a separate module. For example, the temperature determination device 1 can be connected to the microelectromechanical system oscillator 2 through an external port of the microelectromechanical system oscillator 2 to determine the temperature of the environment in which the microelectromechanical system oscillator 2 is located.

[0062] See Figure 8The microelectromechanical system oscillator 2 may include a MEMS die 21 and a CMOS (Complementary Metal-Oxide Semiconductor) die 22. The MEMS die 21 and the CMOS die 22 are electrically coupled. The microelectromechanical system oscillator includes the temperature determination device 1 mentioned in the above embodiments.

[0063] In one embodiment, see Figure 8 The MEMS die 21 and the CMOS die 22 are wire-bonded. The wires used for wire bonding can be gold wire, copper wire, or other metal wires capable of providing an electrical connection. Specifically, the MEMS die 21 and the CMOS die 22 can be wire-bonded as follows: Figure 5 Stacked, side-by-side, or staggered configurations are also possible.

[0064] If the MEMS die 21 and the CMOS die 22 are stacked, they can be bonded or soldered together. The MEMS die 21 can be positioned at the center of the CMOS die 22. In one embodiment, the MEMS die 21 and the CMOS die 22 are stacked and flip-chip bonded together. Flip-chip bonding connects the two dies via solder joints, eliminating the need for additional leads.

[0065] In one embodiment, the first capacitor 11 and the second capacitor 12 in the above embodiments can be arranged together on the MEMS die 21 or on the CMOS die 22, or one can be arranged on the MEMS die 21 and the other on the CMOS die 22, etc.

[0066] In one embodiment, the coupling unit 13 in the above embodiment can be a hybrid circuit arranged within the MEMS oscillator 2. Specifically, the hybrid circuit can be arranged on the CMOS die 22 and connected to the first capacitor 11 and the second capacitor 12. The hybrid circuit can receive the first capacitance value C1 and the second capacitance value C2 to calculate and obtain the coupling value.

[0067] The temperature determination unit 14 in the above embodiments may include a memory disposed on the CMOS die 22, which pre-stores the correspondence between coupling values ​​and temperatures, such as a lookup table. The memory is connected to the hybrid circuit to obtain the coupling values ​​and to obtain the current temperature of the MEMS oscillator 2 based on the coupling values. In other embodiments, the temperature determination unit 14 may include a temperature fitting calculation circuit. The relevant values ​​used for fitting calculation in the temperature fitting calculation circuit can be pre-set. After receiving the coupling value, the temperature fitting calculation circuit can use polynomial fitting calculation to obtain the temperature corresponding to the coupling value.

[0068] In the above embodiments, the output unit 15 can be an output circuit arranged within the MEMS oscillator 2. Specifically, this output circuit can be arranged on the CMOS die 22 and connected to the temperature determination unit 14, such as a memory or a temperature fitting calculation circuit. This output circuit can obtain the current temperature of the MEMS oscillator 2 from the temperature determination unit 14 and output it to subsequent logic circuits. It is understood that the subsequent logic circuits can receive this temperature data to compensate the MEMS oscillator 2, thereby causing the MEMS oscillator 2 to output a signal with the desired frequency. Thus, compensation for frequency deviations caused by temperature variations in the MEMS oscillator 2 can be achieved.

[0069] The following is a description of the methods for determining temperature.

[0070] See Figure 9 The temperature determination method for determining the temperature of the microelectromechanical system oscillator 2 includes:

[0071] S10, obtain the first capacitance value of the first capacitor 11; and obtain the second capacitance value of the second capacitor 12.

[0072] S20, the first capacitance value and the second capacitance value are coupled to obtain the corresponding coupling value, wherein the coupling value is proportional to the temperature of the microelectromechanical system oscillator 2.

[0073] S30, the temperature of the microelectromechanical system oscillator 2 is determined using the coupling value.

[0074] The method for determining the temperature may further include:

[0075] Output the temperature determined in step S30.

[0076] For details, please refer to the description of each module of the temperature determination device 1 in the above embodiments.

[0077] In summary, the temperature determination device 1 of this application utilizes the proportional relationship between the capacitance value of a capacitor and the temperature, and uses the coupling value of the two capacitors to determine the temperature of the microelectromechanical system oscillator 2. Thus, the temperature of the microelectromechanical system oscillator 2 can be measured more accurately.

[0078] The processor involved in this application may be referred to as a CPU (Central Processing Unit), which may be an integrated circuit chip, or a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component.

[0079] The storage media used in this application include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), or optical discs.

[0080] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0081] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0082] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0083] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A temperature determining device applied to a microelectromechanical system oscillator, characterized in that, The temperature determining device includes: A first capacitor is used to output a first capacitance value; wherein, the first capacitance value of the first capacitor is negatively correlated with temperature; A second capacitor is used to output a second capacitance value; wherein the second capacitance value of the second capacitor is positively correlated with temperature; A coupling unit is electrically connected to the first capacitor and the second capacitor respectively, and is used to couple the first capacitance value and the second capacitance value to obtain a corresponding coupling value, wherein the coupling value is proportional to the temperature of the microelectromechanical system oscillator; A temperature determination unit, electrically connected to the coupling unit, is used to determine the temperature of the microelectromechanical system oscillator using the coupling value.

2. The temperature determining device according to claim 1, characterized in that, The coupling unit is used to subtract the first capacitance value from the second capacitance value to obtain the corresponding coupling value.

3. The temperature determining device according to claim 1, characterized in that, The coupling unit is used to use the ratio between the second capacitance value and the first capacitance value as the coupling value.

4. The temperature determining device according to claim 1, characterized in that, The coupling unit is used to determine the sum of the capacitance of the second capacitance value and the first capacitance value, and uses the ratio between the second capacitance value and the sum of the capacitances as the coupling value.

5. The temperature determining device according to claim 1, characterized in that, The first capacitor and the second capacitor are MEMS capacitors.

6. A microelectromechanical system oscillator, characterized in that, The microelectromechanical system oscillator includes: a MEMS die; The CMOS die is electrically coupled to the MEMS die; The microelectromechanical system oscillator is equipped with a temperature determination device as described in any one of claims 1-5.

7. The microelectromechanical system oscillator according to claim 6, characterized in that, The first capacitor and the second capacitor are jointly disposed on the MEMS die or the CMOS die; Alternatively, one of the first capacitor and the second capacitor may be disposed on the MEMS die, and the other may be disposed on the CMOS die.

8. The microelectromechanical system oscillator according to claim 6, characterized in that, The coupling unit and the temperature determination unit are disposed on the CMOS die.

9. A temperature determination method applied to a microelectromechanical system oscillator, characterized in that, The temperature determination method includes: obtaining a first capacitance value of a first capacitor; wherein the first capacitance value of the first capacitor is negatively correlated with temperature; Obtain the second capacitance value of the second capacitor; wherein the second capacitance value of the second capacitor is positively correlated with temperature; The first capacitance value and the second capacitance value are coupled to obtain a corresponding coupling value, wherein the coupling value is proportional to the temperature of the microelectromechanical system oscillator; The temperature of the microelectromechanical system oscillator is determined using the coupling value.

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