TO quartz crystal resonator with low G sensitivity
By introducing a stress isolation structure and a special electrode design into the quartz crystal resonator, combined with a support spring and vacuum encapsulation, the G sensitivity of the quartz crystal resonator is reduced, the problem of large frequency variation is solved, and the stability is improved.
Patent Information
- Application Number
- CN202511577747.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2026-02-06
AI Technical Summary
Existing quartz crystal resonators exhibit significant frequency changes when subjected to external acceleration, resulting in high G-sensitivity and impacting the accuracy and resolution of frequency devices in harsh environments.
A low-G sensitivity TO-type quartz crystal resonator was designed. It adopts TO specification packaging and combines stress isolation structure, special electrode structure and support spring design to reduce stress and mass load. It is fixed and electrically connected by conductive adhesive. The shell and base are cold-pressed and vacuumed.
It effectively reduced the frequency variation of the quartz crystal resonator, improved stability, reduced the G sensitivity from 1.3ppb/g to 0.8ppb/g, and enhanced frequency stability in acceleration environments.
Smart Images
Figure CN121485633A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of quartz crystal resonator technology, and in particular to a TO-type quartz crystal resonator with low G sensitivity. Background Technology
[0002] A quartz crystal resonator is an electronic component that generates frequency signals using the piezoelectric effect of a quartz crystal. It features high precision and high stability, enabling it to generate oscillating signals with precise frequencies in circuits, making it an indispensable component in various electronic devices. Currently, quartz crystal resonators have found wide application in fields such as communication equipment, aerospace, automotive electronics, and industrial equipment.
[0003] Quartz crystal resonators exhibit a force-frequency effect. When subjected to external acceleration, volume stress is generated within the resonator, causing deformation of the internal components. This manifests macroscopically as a change in the resonator's frequency. In the quartz crystal resonator industry, the change in output frequency caused by applied acceleration is typically referred to as G-sensitivity, also known as acceleration sensitivity, and is expressed in ppb / g. The formula for calculating G-sensitivity is as follows:
[0004] Sensitivity G = Δf / (g * f0)
[0005] Where Δf is the frequency change, g is the acceleration applied to the quartz crystal resonator, and f0 is the nominal frequency of the quartz crystal resonator.
[0006] As a core component of frequency devices, the low G-sensitivity of quartz crystal resonators helps ensure the accuracy and resolution sensitivity of frequency devices in environments with high acceleration. In some fields, this is a crucial indicator. Because this is an inherent characteristic of quartz crystal resonators, in practical applications, products with lower G-sensitivity are typically obtained through screening tests, or through compensation designs in the downstream frequency devices to ensure frequency stability under harsh environments. However, the first method only yields a small number of quartz crystal resonators with low G-sensitivity, while the second method requires cumbersome testing procedures. Therefore, directly reducing the G-sensitivity of quartz crystal resonator products is an important direction for improvement in existing technology. Summary of the Invention
[0007] To reduce the acceleration sensitivity of quartz crystal resonators, this invention proposes a low-G-sensitivity TO-type quartz crystal resonator. This invention can reduce stress and mass load, thereby decreasing the G-sensitivity of the quartz crystal resonator.
[0008] The technical solution adopted in this invention is as follows:
[0009] A low-G sensitivity TO-type quartz crystal resonator, packaged in TO specification, includes a housing 1, a quartz oscillator 2, and a base 4. The quartz oscillator 2 includes a quartz crystal wafer 5 and two electrode structures located on the upper and lower surfaces of the quartz crystal wafer 5. The electrode structures include a main electrode 6 and electrode leads 7. Both the quartz crystal wafer 5 and the main electrode 6 are circular. The electrode leads 7 extend radially along the main electrode 6, with their tails forming a fan-shaped ring concentric with the main electrode 6. The quartz crystal wafer 5 has two hollowed-out, fan-shaped stress isolation structures 8. The quartz crystal wafer 5, the stress isolation structures 8, and the main electrode 6 are all concentric. The two stress isolation structures 8 have the same shape and are about the quartz crystal. The central axis of wafer 5 is 180 degrees rotationally symmetrical. The two electrode structures have the same shape and are 180 degrees rotationally symmetrical about the central axis of the quartz wafer 5. Two stress isolation structures 8 correspond one-to-one with the two electrode structures. In each corresponding group, the stress isolation structure 8 is located between the main electrode 6 and the tail of the electrode lead 7, and does not cross the electrode lead 7. There are four supporting springs 9 in the base 4, and five external leads 10 at the bottom. One of the external leads is connected to the grounding terminal and is not connected to the internal supporting spring. The other four external leads are connected to the four supporting springs respectively. The quartz oscillator 2 is mounted on the four supporting springs and is fixed and electrically connected by conductive adhesive.
[0010] Furthermore, the four support springs are identical in shape and are evenly arranged around the central axis of the quartz crystal 5. The two opposing support springs are located at the tails of the two electrode leads 7, and are electrically connected to the tails of the electrode leads 7 by conductive adhesive. The other two opposing support springs are connected to the electrode-free area of the quartz oscillator 2. The connection between each pair of opposing support springs passes through two stress isolation structures 8.
[0011] Furthermore, the quartz wafer 5 adopts a double-angle SC cut, with the first angle phi being 21°56′ and the second angle theta being between 34° and 35°.
[0012] Furthermore, the electrode structure is made of gold, and the electrode structure is connected to the quartz wafer 5 via a chromium transition.
[0013] Furthermore, the outer shell 1 and the base 4 are connected by cold pressure welding, and the interior is evacuated.
[0014] The beneficial effects of this invention are as follows:
[0015] 1. The present invention processes a stress isolation structure on the quartz wafer, which can reduce the influence of stress on the oscillation region of the quartz crystal main electrode when subjected to acceleration, and reduce the mass load of the quartz wafer, thereby reducing the frequency change of the quartz crystal resonator when subjected to acceleration.
[0016] 2. This invention incorporates the stress isolation structure of the quartz crystal wafer and features a special structural design for the main electrodes and electrode leads on the upper and lower surfaces of the quartz oscillator. This design reduces the impact of stress on the oscillation region of the main electrodes of the quartz crystal under acceleration, thereby reducing the frequency change of the quartz crystal resonator under acceleration.
[0017] 3. The present invention has made a special design for the assembly direction of the quartz oscillator and the base. The connection between the quartz oscillator and the support end is isolated from the main electrode of the quartz oscillator through a stress isolation structure, thereby reducing the influence of stress on the oscillation region of the main electrode of the quartz crystal when subjected to acceleration, and thus reducing the frequency change of the quartz crystal resonator when subjected to acceleration.
[0018] 4. This invention reduces the frequency shift of a quartz crystal resonator when subjected to acceleration, thereby improving the vibration resistance of the quartz crystal resonator. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the structure of a quartz crystal resonator in an embodiment of the present invention.
[0020] Figure 2 This is a schematic diagram of the structure of the low-G sensitivity quartz oscillator in an embodiment of the present invention.
[0021] Figure 3 This is a schematic diagram of the structure of a quartz wafer in an embodiment of the present invention.
[0022] Figure 4 This is a schematic diagram showing the installation position of the quartz oscillator inside the quartz crystal resonator in an embodiment of the present invention.
[0023] Figure 5 This is a cross-sectional view of the quartz crystal resonator in an embodiment of the present invention. Detailed Implementation
[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0025] A low-G sensitivity TO-type quartz crystal resonator, such as Figures 1-5 As shown, it includes a base 4, a low-G sensitivity quartz oscillator 2 mounted on the base, a housing 1, and conductive adhesive 3, and is packaged in TO8 specification.
[0026] The low-G sensitivity quartz oscillator consists of a quartz crystal 5, main electrodes 6 on the upper and lower surfaces, and electrode leads 7.
[0027] The main electrode is made of gold, and the main electrode is connected to the quartz wafer by a chromium transition. The upper and lower main electrodes are circular and completely symmetrical, with a diameter between 5 and 6 mm.
[0028] Quartz crystal wafer 5 is a circular quartz crystal with a diameter of 11 mm and a frequency of 10 MHz, using a double-angle SC cut. The first angle, phi, is 21°56′, and the second angle, theta, is between 34° and 35°. Quartz crystal resonators made using double-angle SC-cut quartz crystal wafers exhibit very low stress effects.
[0029] Two stress isolation structures 8 are fabricated on the quartz wafer 5. The structure is a fan-shaped ring structure with a width of 0.5 mm around the main electrodes on the upper and lower surfaces. The two fan-shaped ring structures are completely symmetrical along the diameter direction of the quartz wafer. The center of the two fan-shaped ring structures coincides with the center of the quartz wafer. The fan-shaped ring structure is located in the middle position between the main electrode 6 and the tail end of the electrode lead 7.
[0030] The upper and lower surface electrode leads 7 are specially designed. The tail end of the lead is in a fan-shaped ring along the edge of the quartz wafer, with a width of 1mm. It is separated from the main electrodes of the upper and lower surfaces by a stress isolation structure 8. The upper and lower surface electrode leads can overlap after rotating 180 degrees.
[0031] The base contains four support springs 9 and five external leads 10 at the bottom. The external leads are used to connect to the external circuit. One of the external leads is connected to the ground terminal and not to the internal support springs. The other four external leads are connected to the four internal support springs one by one.
[0032] The low-G sensitivity quartz oscillator is fixed to the support springs according to the design direction, and is secured and electrically connected using conductive adhesive. Two opposing support springs are connected to the tail ends of the electrode leads of the low-G sensitivity quartz oscillator, while the other two opposing support springs are connected to the electrode-free areas of the low-G sensitivity quartz oscillator. The connecting wires of the opposing support springs pass through the stress isolation structure on the quartz wafer, thus isolating them from the main electrode. It is important to note that the electrode leads 7 on the upper surface cannot directly contact the support springs located below the quartz wafer; electrical connection is achieved using conductive adhesive.
[0033] The outer shell 1 and the base 4 are connected by cold pressure welding. The interior is evacuated to a vacuum level better than 2E-4Pa, ensuring that the low-G sensitivity quartz oscillator is in a sealed environment.
[0034] This quartz crystal resonator reduces mass load and stress by designing and fabricating a special stress isolation structure for the quartz wafer. Vibration isolation is achieved through a special structural design of the main electrodes and electrode leads on the upper and lower surfaces of the quartz oscillator, combined with the stress isolation structure of the quartz wafer. Vibration isolation is also achieved by placing the quartz wafer on a support spring in a specific orientation on the base. Ultimately, these structural features reduce the impact of stress on the quartz crystal resonator.
[0035] After testing, the G-sensitivity of the quartz crystal resonator in the above embodiment is 0.8 ppb / g, which is significantly reduced compared to the conventional value of 1.3 ppb / g for quartz crystal resonators. This greatly improves the stability of the quartz crystal resonator in use.
[0036] This invention reduces stress and mass load by using a zero-stress-coefficient cut and employing a special structural design for the quartz crystal wafer and wafer electrodes, thereby reducing the G-sensitivity of the quartz crystal resonator. Compared to conventional products, this invention reduces the frequency change of the quartz crystal resonator under acceleration, further ensuring stability during use.
[0037] In summary, this invention, through vibration isolation and mass load reduction design of the quartz crystal wafer and wafer electrodes, and design of the assembly direction of the quartz oscillator and base, obtains a TO-type quartz crystal resonator with low G sensitivity. Under external acceleration, it effectively reduces the frequency change of this type of quartz crystal resonator, improves its stability, and meets the needs of applications in more fields.
[0038] The above embodiments are merely one implementation method of the present invention and are only used to help understand the method and core idea of the present invention. They should not be used to limit the scope of protection of the present invention. Due to the limitations of textual expression, and the objective existence of infinite specific structures, any modifications or embellishments made without substantial meaning without departing from the main design idea and spirit of the present invention, and which still solve the same technical problem as the present invention, should be included within the scope of protection of the present invention.
Claims
1. A low-G sensitivity TO-type quartz crystal resonator, packaged in TO specification, comprising a housing (1), a quartz oscillator (2), and a base (4), characterized in that, The quartz oscillator (2) includes a quartz crystal (5) and two electrode structures located on the upper and lower surfaces of the quartz crystal (5). The electrode structures include a main electrode (6) and electrode leads (7). Both the quartz crystal (5) and the main electrode (6) are circular. The electrode leads (7) extend radially along the main electrode (6) and form a fan-shaped ring at the tail end, concentric with the main electrode (6). The quartz crystal (5) has two hollowed-out stress isolation structures (8) in the shape of fan rings. The quartz crystal (5), the stress isolation structures (8), and the main electrode (6) are all concentric. The two stress isolation structures (8) have the same shape and are 180 degrees rotationally symmetrical about the central axis of the quartz crystal (5). The two electrode structures have the same shape and are 180 degrees rotationally symmetrical about the central axis of the quartz crystal (5); the two stress isolation structures (8) correspond one-to-one with the two electrode structures. In each corresponding group, the stress isolation structure (8) is located between the main electrode (6) and the tail of the electrode lead (7) and does not cross the electrode lead (7); there are four support springs (9) in the base (4) and five external leads (10) at the bottom. One of the external leads is connected to the grounding end and is not connected to the internal support spring. The other four external leads are connected to the four support springs respectively; the quartz oscillator (2) is mounted on the four support springs and is fixed and electrically connected by conductive glue.
2. The low-G sensitivity TO-type quartz crystal resonator according to claim 1, characterized in that, The four support springs are identical in shape and are evenly arranged around the central axis of the quartz crystal (5). The two opposite support springs are located at the tails of the two electrode leads (7) respectively, and are electrically connected to the tails of the electrode leads (7) through conductive adhesive. The other two opposite support springs are connected to the electrodeless area of the quartz oscillator (2). The connection between each pair of opposite support springs passes through two stress isolation structures (8).
3. A low-G sensitivity TO-type quartz crystal resonator according to claim 1, characterized in that, The quartz wafer (5) adopts a double-angle SC cut, with the first angle phi being 21°56′ and the second angle theta being between 34° and 35°.
4. A low-G sensitivity TO-type quartz crystal resonator according to claim 1, characterized in that, The electrode structure is made of gold, and the electrode structure is connected to the quartz wafer (5) by a chromium transition.
5. A low-G sensitivity TO-type quartz crystal resonator according to claim 1, characterized in that, The outer shell (1) and the base (4) are connected by cold pressure welding, and the inside is vacuumed.