MEMS Oscillator and Electronic Device

Abstract

A MEMS oscillator includes a first baseplate, a MEMS chip, and a second heater. The MEMS chip is disposed on the first baseplate, the MEMS chip includes a first MEMS resonator and a first heater, and the second heater is disposed outside the MEMS chip. The MEMS resonator is directly heated inside the MEMS chip by using the first heater, and is heated outside the MEMS chip by using the second heater.

Claims

1. A micro-electro mechanical system (MEMS) oscillator, comprising: a first baseplate; a MEMS chip located on the first baseplate and comprising: a first MEMS resonator; and a first heater; and a second heater located outside the MEMS chip and comprising a heating coil.

2. (canceled)

3. The MEMS oscillator of claim 1, wherein the MEMS chip is located at a center of the second heater.

4. The MEMS oscillator of claim 1, wherein the second heater is integrated on a surface of the first baseplate.

5. The MEMS oscillator of claim 1, further comprising a complementary metal-oxide-semiconductor (CMOS) chip configured to control the MEMS chip, wherein the CMOS chip and the MEMS chip are located on different surfaces of the first baseplate or are stacked on a first surface of the first baseplate.

6. The MEMS oscillator of claim 1, wherein the second heater is integrated on a surface of the CMOS chip.

7. The MEMS oscillator of claim 1, further comprising a heating chip comprising the second heater, wherein the heating chip and the MEMS chip overlap on the first baseplate.

8. The MEMS oscillator of claim 7, further comprising a complementary metal-oxide-semiconductor (CMOS) chip comprising a second surface, wherein the heating chip is located on a first surface of the first baseplate or is stacked on the second surface.

9. The MEMS oscillator of claim 1, chip further comprising a support beam located at a periphery of the first MEMS resonator and comprising a surface, wherein the support beam is the first heater, or the first heater is located on the surface.

10. The MEMS oscillator of claim 1, wherein the MEMS chip further comprises a first temperature sensor configured to detect a temperature of the first MEMS resonator.

11. The MEMS oscillator of claim 10, wherein the first temperature sensor comprises a second MEMS resonator arranged in parallel with the first MEMS resonator.

12. The MEMS oscillator of claim 10, further comprising: a first proportional-integral-derivative (PID) controller configured to control first power of the first heater based on the temperature; and a second PID controller configured to control second power of the second heater based on an output value of the first PID controller or the temperature.

13. The MEMS oscillator of claim 10, further comprising a second temperature sensor located outside the MEMS chip and configured to detect an external ambient temperature of the MEMS chip.

14. The MEMS oscillator of claim 13, further comprising: a first proportional-integral-derivative (PID) controller configured to control a first power of the first heater based on the temperature; and a second PID controller configured to control a second power of the second heater based on the external ambient temperature.

15. The MEMS oscillator of claim 1, further comprising: a second baseplate; and a packaging cap, wherein the second baseplate and the packaging cap define a cavity, and wherein the first baseplate, the MEMS chip, and the second heater are all located on the second baseplate and in the cavity.

16. The MEMS oscillator of claim 1, further comprising: a base; a packaging cover; and a packaging ring located between the base and the packaging cover, wherein the base, the packaging ring, and the packaging cover define a cavity, and wherein the first baseplate, the MEMS chip, and the second heater are all located on the base in the cavity.

17. An electronic device, comprising: a circuit board; and a micro-electro mechanical system (MEMS) oscillator coupled to the circuit board and comprising: a baseplate; a MEMS chip located on the first baseplate, and comprising: a MEMS resonator; and a first heater; and a second heater located outside the MEMS chip.

18. The electronic device of claim 17, wherein the second heater comprises a heating coil.

19. The electronic device of claim 17, wherein the MEMS chip is located at a center of the second heater.

20. The electronic device of claim 17, wherein the second heater is inside the baseplate.

21. A micro-electro mechanical system (MEMS) oscillator, comprising: a baseplate; a MEMS chip located on the baseplate and comprising: a MEMS resonator; and a first heater; and a second heater located outside the MEMS chip, wherein the MEMS chip is further located in a center of the second heater.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0024] FIG. 1 shows a frequency-temperature, or temperature coefficient of frequency (TCF), curve of a MEMS resonator according to this disclosure.

[0025] FIG. 2 is a diagram of a structure of a MEMS oscillator according to an embodiment of this disclosure.

[0026] FIGS. 3A and 3B are diagrams of an internal structure of a MEMS resonator according to an embodiment of this disclosure.

[0027] FIG. 4 is a diagram of a structure of a MEMS resonator according to an embodiment of this disclosure.

[0028] FIG. 5 is a diagram of a structure of a MEMS resonator according to an embodiment of this disclosure.

[0029] FIG. 6 is a diagram of a structure of a first heater according to an embodiment of this disclosure.

[0030] FIGS. 7A and 7B are diagrams of an internal structure of a MEMS resonator according to an embodiment of this disclosure.

[0031] FIGS. 8A and 8B are diagrams of an internal structure of a MEMS resonator according to an embodiment of this disclosure.

[0032] FIGS. 9A-9C are diagrams of an internal structure of a MEMS resonator according to an embodiment of this disclosure.

[0033] FIGS. 10A and 10B are diagrams of an internal structure of a MEMS resonator according to an embodiment of this disclosure.

[0034] FIG. 11 is a diagram of a structure of a MEMS oscillator according to an embodiment of this disclosure.

DETAILED DESCRIPTION

[0035] To make objectives, technical solutions, and advantages of this disclosure clearer, the following clearly describes the technical solutions in this disclosure with reference to the accompanying drawings in this disclosure. It is clear that the described embodiments are merely some rather than all of embodiments of this disclosure. All other embodiments obtained by a person of ordinary skill in the art based on embodiments of this disclosure without creative efforts shall fall within the protection scope of this disclosure.

[0036] In the specification, embodiments, claims, and accompanying drawings of this disclosure, the terms first, second, and the like are merely intended for distinguishing and description, and shall not be understood as indicating or implying relative importance, or indicating or implying a sequence. At least one piece (item) means one or more, and a plurality of means two or more. The term and/or is used for describing an association relationship between associated objects, and represents that three relationships may exist. For example, A and/or B may represent the following three cases: Only A exists, only B exists, and both A and B exist, where A and B may be singular or plural. The character / generally indicates an or relationship between the associated objects. Installation, connection, being connected to, and the like should be understood in a broad sense, for example, may be a fixed connection, a detachable connection, or an integral connection; or may be a direct connection, an indirect connection through an intermediate medium, or internal communication between two elements. In addition, the terms include, have, and any variant thereof are intended to cover non-exclusive inclusion, for example, include a series of steps or units. A method, system, product, or device is not necessarily limited to those steps or units expressly listed, but may include other steps or units not expressly listed or inherent to such a process, method, product, or device. On, below, left, right, and the like are used only relative to an orientation of components in the accompanying drawings. These directional terms are relative concepts, are used for relative descriptions and clarifications, and may change accordingly as positions at which the components in the accompanying drawings are placed change.

[0037] First, related concepts in this disclosure are explained and described.

[0038] MEMS: indicates a micro-electromechanical system that integrates a type sensor, an actuator, a signal processing unit, a control circuit, and a power supply on a micron-level chip according to a function requirement by using a micro-electromechanical processing technology.

[0039] TCF: Indicates a Change of an Inherent Frequency of a Corresponding Resonator when a Temperature of the Resonator Changes by 1 C. In a Determined Temperature Range.

[0040] An embodiment of this disclosure provides an electronic device. The electronic device includes a MEMS oscillator and another device electrically connected to the MEMS oscillator, for example, a printed circuit board (PCB), which may also be referred to as a circuit board and a controller. This is not limited in this disclosure. Another device may be disposed depending on an actual requirement and based on an actual scenario.

[0041] It may be understood that a resonator as an important component of the oscillator is mainly configured to generate a resonance frequency. Frequency stability of the resonator directly determines performance of the oscillator.

[0042] FIG. 1 shows a TCF curve of a MEMS resonator. With reference to FIG. 1, at an inflection point of the TCF curve, when a temperature changes, a resonance frequency change (namely, a frequency offset) of the resonator is very small. Therefore, for an oven-controlled MEMS oscillator, a temperature of the resonator usually should to be maintained at an inflection point temperature, to ensure stability of the oscillator.

[0043] In addition, for an electrostatic resonator, because of a problem of electrostatic negative stiffness, the resonator is very sensitive to fluctuation of an ambient temperature. For example, in some cases, when a temperature of an external baseplate fluctuates by 0.1 C., the frequency offset of the resonator may reach 3.1 parts per billion (ppb). Furthermore, a thermal stress caused by fluctuation of the ambient temperature also affects the resonance frequency of the MEMS resonator, and the frequency offset may reach more than 0.22 ppb per megapascal (ppb/Mpa).

[0044] In view of this, an embodiment of this disclosure provides a new type of oven-controlled MEMS oscillator (OCMO). The oscillator uses internal and external dual-layer constant-temperature control, and has high frequency stability performance and a capability of resisting environmental interference.

[0045] An application field of the OCMO is not limited in this disclosure. For example, the oscillator (OCMO) may be used in a data communication device, an optical transmission device, a building base band unit (BBU) of a base station, an radio remote unit (RRU), and the like. The data communication device may include a server, a switch, a router, and the like. The optical transmission device may include an optical transport network (OTN) device, a passive optical network (PON) device, and the like.

[0046] For example, in the wireless communication field, the new type of oscillator provided in this embodiment of this disclosure may be used in a BBU in a base station as a clock source, to ensure absolute time synchronization between all base stations in a wireless service. The new type of MEMS oscillator may also be used in a bearer network as a reference source of a synchronization network element, so that time between different base stations is synchronized through a network.

[0047] The following describes specific disposing of the new type of OCMO provided in this embodiment of this disclosure.

[0048] For example, as shown in FIG. 2, an embodiment of this disclosure provides a MEMS oscillator 01. The MEMS oscillator 01 includes a first baseplate 100 and a MEMS chip 101 (e.g., a MEMS die) that is disposed on the first baseplate 100. The MEMS chip 101 includes a MEMS resonator 10 (which may also be referred to as a first MEMS resonator) and first heaters A1. That is, the first heater A1 is manufactured by using a MEMS process, and is integrated in the MEMS DIE. In this case, the MEMS resonator 10 (or the MEMS resonator) may be directly heated inside the MEMS chip 101 by using the first heater A1. For example, the resonator may be heated to an inflection point temperature of a TCF curve. In this way, frequency stability of the resonator can be improved, heating efficiency can be further improved, and power consumption can be reduced.

[0049] Based on this, the MEMS oscillator 01 further includes second heaters A2 located outside the MEMS chip 101. The MEMS chip 101 is heated from the outside by using the second heater A2. When an external ambient temperature changes, it can be ensured that a surface temperature of the MEMS chip 101 is constant and uniform (that is, has a small temperature gradient). In this way, interference caused by an external local temperature change can be resisted, and frequency stability of the resonator is further improved.

[0050] In conclusion, for the MEMS oscillator 01 provided in this embodiment of this disclosure, the first heater is disposed inside the MEMS chip 101 (MEMS DIE), and the second heater is disposed outside the MEMS chip, so that heating is separately performed inside and outside the MEMS chip, thereby implementing internal and external dual-layer constant-temperature control. In this case, the MEMS resonator 10 may be precisely heated inside the MEMS chip directly by using the first heater to an inflection point temperature, so that heating efficiency can be improved, energy consumption can be reduced, and frequency stability of the resonator can be improved. The MEMS resonator 10 is externally heated from the outside of the MEMS chip by using the second heater, so that a surface temperature of the MEMS chip is kept uniform and constant. In this way, the oscillator can well resist environmental interference, and frequency stability of the resonator is further improved.

[0051] The dual-layer constant-temperature oscillator in this disclosure combines internal heating and external heating, and therefore has a wider operating temperature range. It may be understood that, under limited bit resources, a temperature control range and temperature control precision are mutually contradictory, and it is difficult to achieve both. If a disposing manner of dual-layer temperature control is adopted in this disclosure, outer-layer temperature control is performed to cover a wide temperature range, but temperature control precision is slightly poor. For example, the baseplate may be heated from 40 C. to 85 C.-95 C. Inner-layer temperature control can be performed to increase a temperature of the resonator in a small range, to implement high-precision temperature control. For example, the resonator is heated from 85 C. to 105 C. or higher. The internal and external temperature control coordination manner can meet requirements of the oscillator for a wider operating temperature range and a high-temperature environment (for example, 105 C.-125 C.).

[0052] For example, in an existing technology, when a resonator is heated from the outside of a chip to a high-temperature inflection point (for example, above 105 C.) by using an external heater, reliability of the chip is reduced, and high-power consumption is introduced. If a dual-layer temperature control manner is adopted in this disclosure, the resonator is first heated to a low temperature (for example, 85 C.) by using the external second heater, and then the resonator is slightly heated inside the MEMS chip to an inflection point temperature by using the first heater, so that the oscillator not only can work in a high-temperature environment (for example, 105 C.-125 C.), but also has low power consumption.

[0053] In addition, in this disclosure, disposing of outer-layer temperature control can ensure that a surface temperature of the MEMS DIE is constant, that is, a temperature gradient is small. Especially for a resonator with large electrostatic negative stiffness, a high requirement is imposed on stability of an ambient temperature outside the MEMS DIE, so that a problem of stability degradation of a resonator output frequency due to ambient temperature jitter is resolved.

[0054] In addition, for the MEMS oscillator provided in this embodiment of this disclosure, a micro heater (A1) is integrated in the MEMS chip 101 by using a MEMS process, and wafer packaging is implemented, thereby ensuring a small size and high performance of the oscillator.

[0055] It should be noted that, in this embodiment of this disclosure, the MEMS oscillator may be a single-crystal silicon oscillator, a polycrystalline silicon oscillator, a quartz crystal oscillator, an aluminum nitride oscillator, a lithium niobate oscillator, or the like. In other words, a resonator in the MEMS oscillator is made of single-crystal silicon, polycrystalline silicon, a quartz crystal, aluminum nitride, lithium niobate, or the like. This is not limited in this disclosure.

[0056] Certainly, as shown in FIG. 2, another device such as the first baseplate 100 and a CMOS chip 102 (e.g., a CMOS die) may be further disposed in the MEMS oscillator 01. Both the MEMS chip 101 and the CMOS chip 102 are disposed on the first baseplate 100, and the MEMS chip 101 is electrically connected to the CMOS chip 102. A control circuit such as a temperature control circuit, a temperature compensation circuit, an oscillator circuit, and a frequency synthesizer are disposed in the CMOS chip 102, and can control the MEMS chip 101.

[0057] For example, the first baseplate 100 may be a circuit board, and the MEMS chip 101 and the CMOS chip 102 may be electrically connected to the first baseplate 100, so that the MEMS chip 101 and the CMOS chip 102 may be electrically connected through the first baseplate 100.

[0058] For a relative position relationship between the MEMS chip 101 and the CMOS chip 102 on the first baseplate 100, to reduce an area of the MEMS oscillator 01 as much as possible, in some possible implementations, as shown in FIGS. 3A and 3B, projections of the MEMS chip 101 and the CMOS chip 102 on the first baseplate 100 may be arranged to have an overlapping region. That is, the MEMS chip 101 and the CMOS chip 102 are disposed opposite to each other. For example, in some possible implementations, as shown in FIG. 3A, the MEMS chip 101 and the CMOS chip 102 may be stacked on a surface of the first baseplate 100. For another example, in some possible implementations, as shown in FIG. 3B, the MEMS chip 101 and the CMOS chip 102 are respectively disposed on two opposite different surfaces of the first baseplate 100, and positions of the MEMS chip 101 and the CMOS chip 102 are opposite to each other.

[0059] In addition, as shown in FIG. 4, in the MEMS chip 101, a support beam 11 is disposed at a periphery of the MEMS resonator 10, and the MEMS resonator 10 is connected to a substrate 12 through the support beam 11. A joint between the MEMS resonator 10 and the support beam 11 and a joint between the support beam 11 and the substrate 12 may be usually referred to as an anchor.

[0060] The following specifically describes related disposing of the first heater A1 and the second heater A2.

[0061] For disposing of the first heater A1:

[0062] For example, in some possible implementations, as shown in FIG. 4, the first heater A1 may be a metal coil structure disposed on a surface of the support beam 11.

[0063] For another example, in some possible implementations, the support beam 11 may be used as the first heater A1. For example, the support beam 11 may be obtained through etching on a heavily doped silicon (Si) wafer (above 4.7e19/cm.sup.3) by using a deep reactive-ion etching (DRIE) process, to implement a heating function through the support beam 11.

[0064] For another example, in some possible implementations, an insulation layer may be deposited on the support beam 11 by using an insulation material (for example, silicon nitride (Si.sub.3N.sub.4), aluminum nitride (AlN), or silicon dioxide (SiO.sub.2)), and then a layer of polycrystalline silicon is deposited on the insulation layer as the first heater A1.

[0065] In this disclosure, a shape, a quantity, and other settings of first heaters A1 are not limited, and may be set depending on an actual requirement.

[0066] Certainly, to ensure that the first heater A1 uniformly heats the MEMS resonator 10, in some possible implementations, first heaters A1 may be symmetrically disposed around all sides of the MEMS resonator 10, for example, disposed on a left side and a right side and on a front side and a rear side.

[0067] In addition, to measure a temperature of the MEMS chip 101, in some possible implementations, as shown in FIG. 5, a first temperature sensor SE1 may be disposed inside the MEMS chip 101, so that the temperature of the MEMS resonator 10 is detected by using the first temperature sensor SE1, to control power of the heaters (A1 and A2), thereby implementing constant-temperature control of the MEMS resonator 10.

[0068] A disposing form of the first temperature sensor SE1 is not limited in this disclosure, and may be set depending on an actual requirement.

[0069] For example, as shown in FIG. 5, in some possible implementations, the first temperature sensor SE1 may use a disposing manner of a MEMS resonator. Two MEMS resonators may be arranged in parallel inside the MEMS chip 101, namely, the MEMS resonator 10 (a first MEMS resonator) and a MEMS resonator 20 (a second MEMS resonator). The MEMS resonator 10 is configured to output a working clock signal. The MEMS resonator 20 is used as the first temperature sensor SE1. A clock signal output by the MEMS resonator 20 is used to detect the temperature of the MEMS resonator 10. The temperature of the MEMS resonator 10 may be reversely calculated by measuring a frequency difference between the MEMS resonator 20 and the MEMS resonator 10.

[0070] For example, for the two MEMS resonators (10 and 20) in the MEMS chip 101, the two MEMS resonators (10 and 20) have close resonance frequencies, but the two MEMS resonators have different TCF curves. A TCF of the MEMS resonator 20 is very large, for example, 10 parts per million per degree Celcius (ppm/C), and the TCF curve is relatively linear. However, a TCF of the MEMS resonator 10 is small, for example, 1 ppm/C, and the TCF curve is of a parabolic shape, that is, has an inflection point temperature. For example, the inflection point temperature of the MEMS resonator 10 is 105 C.-125 C., and the TCF is less than 0.1 ppm/C within a deviation of 1 C. (namely, +1 C.) of the inflection point temperature.

[0071] For disposing of the second heater A2:

[0072] First, a disposing form of the second heater A2 is not limited in this disclosure, and may be set depending on an actual requirement.

[0073] For example, in some possible implementations, the second heater A2 may be a micro heater. For example, the micro heater may be made of a material such as platinum (Pt), gold (Au), silver (Ag), nichrome (NiCr), nickel (Ni), tungsten (W), titanium (Ti), aluminum (Al), copper (Cu), graphene, carbon nanotube (CNT), titanium nitride (TiN), gallium nitride (GaN), gallium arsenide (GaAs), nickel-cobalt-iron alloy (NiCoFe alloy), and polycrystalline silicon (Poly-Si), and a thin layer coil is deposited on the baseplate by using a micromachining process. For example, the second heater A2 may be directly integrated on a surface of or inside the first baseplate 100, or may be integrated on a surface of the CMOS chip 102.

[0074] For another example, in some possible implementations, the second heater A2 may be a micro-heating chip, a thin film heater, or the like.

[0075] Certainly, to ensure that the second heater A2 uniformly heats the MEMS chip 101, in some possible implementations, with reference to FIG. 6, the MEMS chip 101 may be disposed in the middle relative to the second heater A2. In other words, central regions of projections of the second heater A2 and the MEMS chip 101 on the first baseplate 100 overlap or approximately overlap. In this way, the second heater A2 may uniformly heat the MEMS chip 101 from all sides.

[0076] A shape of a heating element in the second heater A2 is not limited in this disclosure. The heating element may be of a simple line pattern, or may be of a complex irregular pattern, or the like, to provide uniform heat distribution for the MEMS chip 101.

[0077] The following specifically describes disposing positions of the second heater A2 in different disposing manners.

Disposing Manner 1

[0078] As shown in FIGS. 7A and 7B, in some possible implementations, the second heater A2 may be directly integrated on a surface of the first baseplate 100. In this case, the MEMS chip 101 and the CMOS chip 102 may be disposed depending on an actual requirement.

[0079] For example, in some possible implementations, as shown in FIG. 7A, the MEMS chip 101 and the CMOS chip 102 are respectively disposed on two opposite different surfaces of the first baseplate 100.

[0080] For another example, in some possible implementations, as shown in FIG. 7B, the MEMS chip 101 and the CMOS chip 102 may be stacked on a surface of the first baseplate 100, and the MEMS chip 101 is located on a side that is of the CMOS chip 102 and that is away from the first baseplate 100.

[0081] In the disposing manner 1, the second heater A2 is integrated on the surface of the first baseplate 100, so that the MEMS chip 101 is heated by heating the first baseplate 100.

[0082] FIGS. 7A and 7B are an example in which second heaters A2 are distributed in a peripheral region of the MEMS chip 101. To be specific, an example in which projections of the second heater A2 and the MEMS chip 101 on the first baseplate 100 do not overlap is used for description. However, this disclosure is not limited thereto. In some other possible implementations, there may be an overlapping region between projections of the second heater A2 and the MEMS chip 101 on the first baseplate 100. This is not limited in this disclosure, and may be set depending on an actual requirement.

[0083] Certainly, in another possible implementation, the second heater A2 may be directly integrated inside the first baseplate 100. For details about the MEMS chip 101 and the CMOS chip 102, refer to FIGS. 7A and 7B and the corresponding text descriptions.

Disposing Manner 2

[0084] As shown in FIGS. 8A and 8B, in some possible implementations, the second heater A2 may be directly integrated on a surface of the CMOS chip 102. For example, the second heater A2 may be directly integrated on a surface that is of the CMOS chip 102 and that is away from a side of the first baseplate 100. In this case, a position of the MEMS chip 101 may be set depending on an actual requirement.

[0085] For example, in some possible implementations, as shown in FIG. 8A, the MEMS chip 101 and the CMOS chip 102 are respectively disposed on two opposite different surfaces of the first baseplate 100. In this case, the second heater A2 may heat the MEMS chip 101 by heating the first baseplate 100.

[0086] For another example, in some possible implementations, as shown in FIG. 8B, the MEMS chip 101 may be directly stacked on a surface on which the second heater A2 is disposed on the CMOS chip 102, so that the second heater A2 can heat the MEMS chip 101 from the bottom of the MEMS chip 101.

Disposing Manner 3

[0087] As shown in FIGS. 9A-9C, in some possible implementations, the second heater A2 uses a heating chip 103, and the heating chip 103 may be directly disposed on a surface of the first baseplate 100. In this case, relative positions of the MEMS chip 101 and the CMOS chip 102 may be set depending on an actual requirement.

[0088] For example, in some possible implementations, as shown in FIG. 9A, the heating chip 103 is disposed on an upper surface of the first baseplate 100, the MEMS chip 101 is stacked on an upper surface of the heating chip 103, and the CMOS chip 102 is disposed on a lower surface of the first baseplate 100, so that the heating chip 103 directly heats the MEMS chip 101 from the bottom.

[0089] For another example, in some possible implementations, as shown in FIG. 9B, the heating chip 103 is disposed on an upper surface of the first baseplate 100, the CMOS chip 102 is stacked on an upper surface of the heating chip 103, and the MEMS chip 101 is stacked on an upper surface of the CMOS chip 102, so that the heating chip 103 first heats the CMOS chip 102 and then heats the MEMS chip 101.

[0090] For another example, in some possible implementations, as shown in FIG. 9C, the MEMS chip 101 is disposed on an upper surface of the first baseplate 100, the heating chip 103 is disposed on a lower surface of the first baseplate 100, the CMOS chip 102 is stacked on a lower surface of the heating chip 103, so that the heating chip 103 heats the MEMS chip 101 by heating the first baseplate 100.

Disposing Manner 4

[0091] As shown in FIGS. 10A and 10B, in some possible implementations, the second heater A2 uses a heating chip 103, and the heating chip 103 may be stacked on a surface of the CMOS chip 102. For example, the heating chip 103 may be stacked on a surface that is of the CMOS chip 102 and that is away from a side of the first baseplate 100. In this case, relative positions of the MEMS chip 101 and the CMOS chip 102 may be set depending on an actual requirement.

[0092] For example, in some possible implementations, as shown in FIG. 10A, the CMOS chip 102 is disposed on an upper surface of the first baseplate 100, the heating chip 103 is stacked on an upper surface of the CMOS chip 102, and the MEMS chip 101 is stacked on an upper surface of the heating chip 103, so that the heating chip 103 directly heats the MEMS chip from the bottom.

[0093] For another example, in some possible implementations, as shown in FIG. 10B, the CMOS chip 102 is disposed on a lower surface of the first baseplate 100, the heating chip 103 is stacked on a lower surface of the CMOS chip 102, and the MEMS chip 101 is disposed on an upper surface of the first baseplate 100, so that the heating chip 103 heats the CMOS chip 102 and the first baseplate 100, and then heats the MEMS chip 101.

[0094] The following describes dual-layer temperature control of the MEMS resonator 10 inside the MEMS chip 101 with reference to the first heater A1 and the second heater A2.

[0095] For example, a first PID controller and a second PID controller may be disposed in the MEMS oscillator 01. The first PID controller and the second PID controller respectively control power of the first heater A1 and the second heater A2, so that a temperature of the MEMS resonator 10 is maintained at an inflection point temperature, thereby ensuring stability of the oscillator.

[0096] For example, the first PID controller may adjust an output electrical signal (for example, a voltage signal or a current signal) based on a temperature measurement value obtained by the first temperature sensor SE1 disposed inside the MEMS chip 101, to control the power of the first heater A1.

for the Second PID Controller:

[0097] For example, in some possible implementations, in the MEMS oscillator 01, a second temperature sensor may be disposed outside the MEMS chip 101, and an external ambient temperature of the MEMS chip 101 is detected by using the second temperature sensor. A disposing manner and a specific position of the second temperature sensor may be set according to a requirement, provided that a requirement for external temperature measurement of the MEMS chip 101 is met. This is not limited in this disclosure. In this case, the second PID controller may adjust an output electrical signal (for example, a voltage signal or a current signal) based on a temperature measurement value obtained by the second temperature sensor, to control the power of the second heater A2.

[0098] For example, in some possible implementations, in the MEMS oscillator 01, in a case in which no additional temperature sensor is disposed outside the MEMS chip 101, in some embodiments, the second PID controller may control the power of the second heater A2 based on an output value of the first PID controller; or in some embodiments, the second PID controller may adjust an output electrical signal (for example, a voltage signal or a current signal) based on the temperature measurement value obtained by the first temperature sensor SE1 inside the MEMS chip 101, to control the power of the second heater A2.

[0099] For example, for the MEMS oscillator 01 shown in FIG. 2, in some embodiments, the second PID controller may control the power of the second heater A2, to heat the first baseplate 100 to 85 C.-95 C. Correspondingly, in this case, the temperature of the MEMS resonator 10 in the MEMS chip 101 is initially increased to 85 C.-95 C. Then, the first PID controller may control the power of the first heater A1, and the MEMS resonator 10 inside the MEMS chip 101 is further heated to 105 C.-125 C., so that the MEMS oscillator 01 not only can work at a high temperature, but also has low power consumption.

[0100] In addition, a packaging manner of the MEMS oscillator 01 is not limited in this disclosure. A proper packaging manner may be selected depending on an actual requirement and based on an actual application scenario.

[0101] For example, in some possible implementations, as shown in FIG. 2, the MEMS oscillator 01 may further include a second baseplate 200 and a packaging cap 300. Devices such as the first baseplate 100, the MEMS chip 101, and the second heater 102 are all located on the second baseplate 200 and are electrically connected to the second baseplate 200, to implement interconnection and communication with an external device through the second baseplate 200. The packaging cap 300 is disposed on the second baseplate 200, and is located on outer sides of devices such as the first baseplate 100, the MEMS chip 101, and the second heater 102. A cavity is formed between the packaging cap 300 and the second baseplate 200, so that the devices such as the first baseplate 100, the MEMS chip 101, and the second heater 102 are packaged inside the cavity, that is, an enclosed environment is formed outside the MEMS chip 101. For example, the second baseplate 200 may be a circuit board, but this is not limited thereto.

[0102] For another example, in some possible implementations, as shown in FIG. 11, the MEMS oscillator 01 further includes a base 201, a packaging ring 301, and a packaging cover 302. The devices such as the first baseplate 100, the MEMS chip 101, and the second heater 102 are all located on the base 201, and are electrically connected to the base 201, to implement interconnection and communication with an external device through the base 201. The packaging ring 301 is disposed on the base 201, and is located on the outer sides of the devices such as the first baseplate 100, the MEMS chip 101, and the second heater 102. The packaging cover 302 covers the top of the packaging ring 301. In this case, a cavity is enclosed by the packaging cover 302, the packaging ring 301, and the base 201, so that the devices such as the first baseplate 100, the MEMS chip 101, and the second heater 102 are packaged inside the cavity, that is, an enclosed environment is formed outside the MEMS chip 101. For example, the base 201 may be a ceramic base, but this is not limited thereto.

[0103] The foregoing descriptions are merely specific implementations of this disclosure, but are not intended to limit the protection scope of this disclosure. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this disclosure shall fall within the protection scope of this disclosure. Therefore, the protection scope of this disclosure shall be subject to the protection scope of the claims.