Quartz crystal resonator with low power consumption and high precision

Abstract

The utility model discloses a quartz crystal resonator with low power consumption and high precision, which relates to the technical field of quartz crystal resonators, and comprises a bottom base, a quartz wafer and a packaging upper cover, the bottom base and the packaging upper cover are covered to form a cavity, the quartz wafer is placed in the cavity, the quartz wafer is provided with an electrode, and the electrode is connected with the packaging upper cover. The area of the electrode is (0.7-0.82 mm) * (0.8-0.95 mm), the four corners of the electrode are each of a fillet structure, and the radius of each fillet is R 0.05-R 0.15. According to the quartz crystal resonator with low power consumption and high precision provided by the utility model, the resistance of the quartz crystal is reduced, the energy loss of the crystal oscillator is reduced, parasitic vibration and frequency hopping phenomena are avoided, and the quartz crystal resonator has high stability, high precision and excellent anti-vibration performance.

Description

TECHNICAL FIELD

[0001] The utility model relates to quartz crystal resonator technical field, concretely relates to a low -power consumption high -precision quartz crystal resonator. BACKGROUND

[0002] The quartz crystal resonator is widely used at present and is closely related to our life, with the improvement of life quality, the requirement of crystal is also more and more strict. Quartz crystal resonator is the electronic component needed by numerous electronic products, and is called the "heart" in electronic equipment. Quartz crystal oscillator is widely used in electronic clock, computer, mobile phone, automobile electronics, industrial automation, security equipment, aviation equipment and other fields. These application fields choose high stability quartz crystal resonator because it has the advantages of high frequency, miniaturization, high precision, high stability and low power consumption, which can meet the high requirement of various electronic equipment on frequency stability. The C0 small TS value big crystal resonator on the market is easy to be affected by stray capacitance, and the frequency temperature stability is poor, and the starting speed is also slow. Larger C0 makes the reactance of the oscillation circuit larger before reaching the nominal frequency, and the starting is fast. When the quartz crystal resonator of the same load C0 value increases, TS value will decrease, and TS value reflects the change amount of frequency when the load capacitance changes. The smaller the TS value is, the smaller the influence of load capacitance change on frequency is, and the better the frequency stability of the resonator is. On the contrary, the larger the TS value is, the greater the influence of load capacitance change on frequency is, which may cause the instability of frequency. In order to have the advantages of high stability, high precision, excellent anti-vibration performance in the circuit, high mechanical strength and the like, C0 and TS value are the key. C0 is static capacitor (static parallel capacitor), also known as the combination of electrode capacitance CE and stray capacitance CH. It is the capacitance that can be directly measured at the terminal of the quartz oscillator, including electrode capacitance CE and holding and stray capacitance CH3 through the shell. The size of C0 will affect the resonant frequency and stability of the quartz crystal oscillator. TS sensitivity (TrimSensitivity) refers to the change amount of frequency when the load capacitance changes. The unit of TS sensitivity is ppm / pF, which represents the change amount of crystal frequency when the load capacitance changes by 1pF. Low TS sensitivity means that the crystal frequency is not sensitive to the change of load capacitance, and the frequency stability is higher. UTILITY MODEL CONTENTS

[0003] The technical problem to be solved by the utility model

[0004] The technical problem to be solved by the utility model is to provide a low-power consumption high-precision quartz crystal resonator, the resistance of the quartz crystal is reduced, the energy loss of the crystal oscillator is reduced, the parasitic vibration and frequency hopping phenomenon are avoided, and the quartz crystal resonator has high stability and high precision and excellent anti-vibration performance.

[0005] Technical solutions

[0006] To solve the above problems, the technical solutions provided by the utility model are:

[0007] A low-power high-precision quartz crystal resonator, comprising a bottom base, a quartz wafer, and a packaging upper cover, the bottom base and the packaging upper cover are combined to form a cavity, the quartz wafer is placed in the cavity, the quartz wafer is provided with an electrode, the area of the electrode is 0.7-0.82mm*0.8-0.95mm, and the four corners of the electrode are all round corner structures with a round corner radius of R0.05-R0.15.

[0008] The area of the electrode on the quartz wafer is accurately controlled to be between 0.7-0.82mm*0.8-0.95mm, the increase of the electrode area improves the static capacitance (C0 value) and reduces the load capacitance sensitivity (TS value) to <15ppm / pF, and the frequency stability is improved by more than 40%; and the four corners of the electrode are designed as round corner structures with a round corner radius range of R0.05-R0.15, which reduces the parasitic capacitance: by reducing the sharpness of the electrode edge, the parasitic capacitance caused by the edge effect can be effectively reduced, thereby reducing the C0 value. The lower C0 value helps to improve the frequency stability of the resonator, making it more suitable for applications requiring high-precision clock signals.

[0009] The round corner structure can make the electric field more evenly distributed on the electrode surface, reduce the nonlinear distortion caused by excessive local electric field strength, and further improve the signal quality. Compared with the right angle or acute angle design, the round corner structure can better disperse stress and increase the mechanical strength of the electrode area, which is very important for improving the overall durability and reliability of the resonator. The round corner structure eliminates the right angle electric field concentration effect, reduces the edge parasitic vibration, and makes the crystal oscillator resistant to mechanical impact with a frequency shift of <±2ppm under a 3g amplitude.

[0010] As an option, the joint between the packaging upper cover and the bottom base is welded and sealed by a nickel alloy Kovar ring.

[0011] Improve the air tightness and ensure the stability of the internal environment: welding and sealing with a nickel alloy Kovar ring can greatly improve the air tightness of the quartz crystal resonator. This helps to create a stable internal environment, preventing moisture, oxygen and other pollutants in the external air from entering the device interior, thereby avoiding damage to the quartz wafer or affecting its normal work. This is particularly important for applications requiring very high stability, such as aerospace, medical equipment, etc.

[0012] Reduced thermal stress, enhanced structural reliability: Due to the similar thermal expansion coefficients of the nickel alloy Kovar ring and many commonly used packaging materials (such as ceramics, glass), it can effectively reduce the thermal stress caused by the inconsistent thermal expansion between different materials during temperature changes. This characteristic helps to extend the service life of the device and improve its reliability under extreme temperature conditions. For example, in satellite communication systems, the device may face a huge temperature difference from extremely low temperature to high temperature, at which time good thermal matching performance is particularly important.

[0013] Simplified manufacturing process, improved production efficiency: Compared with other complex packaging technologies, such as gold-tin eutectic soldering, the nickel alloy Kovar ring solder sealing process is relatively simple and easy to automate production. This means that production costs can be reduced while ensuring quality and increasing production. For mass-produced electronic products, this is a very important advantage. In addition, the process has relatively low requirements for equipment, further reducing the initial investment threshold.

[0014] Improved electrical performance, support for high-frequency applications: Good sealing not only prevents external interference factors from entering, but also improves the electrical performance inside the device. By reducing the effects of leakage current and parasitic capacitance, the nickel alloy Kovar ring solder sealing helps to increase the upper limit of the operating frequency of the quartz crystal resonator and its precision, making it more suitable for high-frequency applications required in modern communication systems.

[0015] As an option, the welding interface of the nickel alloy Kovar ring is trapezoidal in cross-section.

[0016] The trapezoidal welding cross-section increases the airtightness and reduces the oxygen permeability of the cavity to <10⁻ 7 Pa·m³ / s², external humidity / dust interference is reduced by 60%.

[0017] As an option, the quartz wafer is fixed to the bottom base by ultraviolet curing conductive glue, and the thickness of the conductive glue is 10-15 μm.

[0018] The glue thickness limits the wafer displacement error to ≤0.5 μm, and the stress is uniformly distributed.

[0019] As an option, the cured conductive glue contains silica microsphere particles with a spacing of 0.05-0.1 mm.

[0020] The silica microspheres (spacing 0.05-0.1 mm) disperse vibration energy, reducing the resonant phase noise to -150 dBc / Hz.

[0021] As an option, the surface roughness of the quartz wafer is less than 0.7 μm.

[0022] Smooth surface reduces the coefficient of friction (μ <0.2) at the interface, reducing energy consumption by 8-10%.

[0023] As optional, the quartz wafer is connected with the electrode on the other side of the pillow structure.

[0024] Non-contact support avoids vibration coupling, and temperature drift coefficient is optimized to 0.03ppm / ℃, and is suitable for anti-tossing scenes of automobile electronics.

[0025] As optional, the bottom base is an integral structure.

[0026] Internal stress difference is less than 5MPa, frequency dispersion caused by packaging deformation is reduced, and batch consistency is improved by 30%.

[0027] Beneficial effects

[0028] Compared with the prior art, the technical scheme has the beneficial effects that:

[0029] The technical scheme provided by the utility model increases the area of the electrode, so that the C0 value is large, the TS value of the crystal oscillator is not sensitive to the change of the load capacitor, the resistance of the quartz crystal is reduced, the energy loss of the crystal oscillator is reduced, the right angle of the electrode is changed to an r angle, the parasitic vibration and frequency hopping phenomenon are avoided, the stability and precision of the quartz crystal resonator are improved, the anti-vibration performance in the circuit is excellent, and the quartz crystal resonator can be applied in relatively harsh vibration environments such as automobile electronics, medical instruments and industrial fields. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A structure diagram of a low-power-consumption high-precision quartz crystal resonator is provided for the embodiment of the utility model;

[0031] Figure 2 A structure diagram of a traditional quartz crystal resonator is provided for the embodiment of the utility model;

[0032] 1, electrode; 2, quartz wafer; 3, bottom base; 4, first angle; 5, second angle; 6, third angle. DETAILED DESCRIPTION

[0033] In order to further understand the content of the utility model, the utility model is described in detail in combination with the drawings and the embodiment.

[0034] EMBODIMENT

[0035] In combination with the drawings, Figures 1-2A low-power, high-precision quartz crystal resonator includes a bottom base 3, a quartz crystal 2, and a top cover. The bottom base 3 and the top cover are joined to form a cavity, within which the quartz crystal 2 is placed. The quartz crystal 2 is provided with electrodes 1, the area of ​​which is 0.7~0.82mm*0.8~0.95mm. The four corners of the electrodes 1 are rounded with a radius of R0.05~R0.15. In this embodiment, the area of ​​the electrodes 1 can be 0.7mm*0.8mm, 0.78mm*0.93mm, or 0.82mm*0.95mm.

[0036] It includes a quartz crystal resonator base 3 and a quartz crystal wafer 2. As described above, the quartz crystal wafer 2 has electrodes 1. The quartz crystal wafer 2 is fixed to the quartz crystal resonator base 3 by dispensing adhesive and encapsulated with a metal cover to form an effective circuit.

[0037] Without altering the area and volume of the base 3 and quartz crystal 2 of the crystal resonator, the area and volume of electrode 1 are directly proportional to the value of C0. The larger the area of ​​electrode 1, the larger the value of C0, and vice versa. The coating apparatus for fabricating the area of ​​electrode 1 is... Figure 1 The 0.7*0.78mm enlargement has been changed to Figure 2 The area of ​​electrode 1 is increased by 0.7~0.82*0.8~0.95mm. Under the same load, the TS value also decreases from 15ppm / pf to 7ppm / pf, thus affecting the frequency stability of the quartz crystal resonator.

[0038] According to the qualitative expression of resistance: R=T3r / 8AE2, where: R-equivalent resistance of crystal element; T-crystal thickness; r-damping coefficient; A-crystal area; E-piezoelectric stress constant.

[0039] As can be seen from this formula, the larger the area of ​​electrode 1, the smaller the resistance. As the area of ​​electrode 1 increases, the resistance of the quartz crystal resonator decreases. With a smaller resistance, the crystal loses less energy, thus maintaining the output frequency more stably and reducing the probability of distortion and jitter.

[0040] The electrical test parameters before and after verification are as follows:

[0041] Electrode area C0 value Resistance TS value Parasitic vibration Test result Before verification 0.7*0.78 mm 0.5 pf 20~26 Ω 15~20 ppm / pf NG NG After verification 0.7~0.82*0.8~0.95 mm 0.8 pf 17~21 Ω 7~12 ppm / pf OK OK

[0042] Due to the increase in the area of ​​electrode 1, parasitic phenomena occur in the quartz crystal resonator. These parasitic phenomena mainly manifest as the frequency deviating from the required value, causing the circuit to malfunction. To prevent these parasitic phenomena, the attached... Figure 2 The 90° first angle 4 is changed to an appendix. Figure 1 The r-angle, R0.1, with appended Figure 2 The second angle 5 and the third angle 6 are both changed from R0.3 to attached...Figure 1 The angle R0.1 of the R corner directly affects the electric field distribution and the current density distribution of the electrode 1. Smaller R corner can reduce the edge effect, improve the uniformity and stability of the electrode 1, avoid parasitic vibration and frequency hopping phenomenon. Long time use can also maintain excellent stability, which makes it excellent in applications requiring high precision stable clock frequency. The anti-vibration performance in the circuit is very good, which can maintain high stability in the mechanical amplitude range of 2 to 3g, and has strong anti-vibration interruption performance.

[0043] The joint between the package upper cover and the bottom base 3 is welded and sealed by a nickel alloy Kovar ring. The welding interface of the nickel alloy Kovar ring is in a trapezoidal cross section.

[0044] The quartz wafer 2 is fixed to the bottom base 3 by ultraviolet curing conductive glue, and the thickness of the conductive glue is 10-15μm.

[0045] The cured product of the conductive glue contains silica microsphere particles with a spacing of 0.05-0.1mm.

[0046] The surface roughness of the quartz wafer 2 is less than 0.7μm.

[0047] The opposite side of the quartz wafer connected to the electrode 1 is in a pillow structure.

[0048] The bottom base 3 is an integrally formed structure.

[0049] The above describes the utility model and its embodiments in a schematic manner, which is not restrictive, and the drawings shown are only one of the embodiments of the utility model, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired thereby, without departing from the creative purpose of the utility model, similar structural modes and embodiments can be designed without creativity, which should all belong to the protection scope of the utility model.

Claims

1. A low-power consumption high-precision quartz crystal resonator, characterized by comprising: It comprises a bottom base, a quartz wafer and a packaging upper cover, the bottom base and the packaging upper cover are combined to form a cavity, the quartz wafer is placed in the cavity, the quartz wafer is provided with an electrode, the area of the electrode is 0.7-0.82mm*0.8-0.95mm, the four corners of the electrode are all round corner structures, and the round corner radius is R0.05-R0.

15.

2. The low-power high-precision quartz crystal resonator according to claim 1, wherein The joint between the packaging upper cover and the bottom base is welded and sealed by a nickel alloy Kovar ring.

3. The low-power high-precision quartz crystal resonator according to claim 2, wherein The welding interface of the nickel alloy Kovar ring is in a trapezoidal cross section.

4. The low-power high-precision quartz crystal resonator according to claim 1, wherein The quartz wafer is fixed to the bottom base by ultraviolet curing conductive glue, and the thickness of the conductive glue is 10-15μm.

5. The low-power high-precision quartz crystal resonator according to claim 4, wherein The curing product of the conductive glue contains silica microsphere particles with a spacing of 0.05-0.1mm.

6. The low-power high-precision quartz crystal resonator according to claim 1, wherein The surface roughness of the quartz wafer is less than 0.7μm.

7. The low-power high-precision quartz crystal resonator of claim 1, wherein, The opposite side of the quartz wafer connected to the electrode is a pillow structure.

8. The low-power high-precision quartz crystal resonator according to any one of claims 1 to 7, characterized in that, The bottom base is an integral molding structure.

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