High-stability temperature-compensated quartz crystal oscillator

Abstract

The utility model relates to a high stability temperature compensation quartz crystal oscillator, including the crystal base and the lower ceramic base of upper and lower stacking, the crystal base lower part has an upper recess, and the compensation chip is installed in this upper recess, the lower ceramic base upper part has a lower recess, and the quartz chip is installed in this lower recess, and the upper recess and the lower recess butt joint and splice to form an inner chamber, and the quartz chip includes quartz wafer, the quartz wafer is composed of fixed section wafer and turning section wafer, and one end of the fixed section wafer is provided with the bending turning section wafer. The utility model can reduce the difference between the temperature perceived by the compensation chip and the environmental temperature of the quartz wafer, provide accurate temperature compensation frequency, achieve the high stability of the frequency when temperature transient, and the quartz wafer with corner structure is designed, and under the double action of the corner structure and the partition through -hole, the stability of the quartz wafer work can be effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of quartz crystal frequency components, and in particular to a high-stability temperature-compensated quartz crystal oscillator. Background Technology

[0002] Temperature-compensated quartz crystal oscillators typically consist of a piezoelectric quartz wafer, a compensation chip, conductive adhesive, a ceramic substrate, and a metal cover. The piezoelectric quartz wafer is usually rectangular or circular, and the substrate typically has a recessed groove on the back to hold the compensation chip. Electrodes are plated on both the top and bottom surfaces of the piezoelectric quartz wafer, which is then fixed to the substrate by conductive adhesive. An AC voltage is applied through pins to connect the compensation chip and the top and bottom electrodes of the quartz wafer, causing the quartz wafer to produce an inverse piezoelectric effect, thus generating oscillation. Simultaneously, the compensation chip senses the ambient temperature and adjusts the voltage accordingly to compensate for the output frequency, resulting in a relatively stable output frequency.

[0003] With the continuous development of electronic products, especially GPS and satellite communication, more stringent requirements have been placed on temperature-compensated quartz crystal oscillators. Currently, in most quartz crystal oscillator systems, the compensation chip and the quartz crystal are not located in the same cavity. When the external temperature changes, there is a difference between the temperature sensed by the compensation chip and the temperature conducted to the quartz crystal through the ceramic substrate and conductive adhesive. This causes a deviation in the frequency compensated by the chip, resulting in a lag effect where the output frequency cannot keep pace with the temperature change. This leads to product malfunctions, significant frequency fluctuations during customer board testing, and unstable connections or signal loss. Furthermore, traditional temperature-compensated quartz crystal oscillators use metal or ceramic substrates as the top cover structure, which has relatively poor flatness and is prone to misalignment during sealing and welding. Temperature conduction issues can also cause thermal frequency drift. Finally, the influence of stress and other factors on the quartz crystal must be considered. Therefore, a highly stable temperature-compensated quartz crystal oscillator is needed to solve these problems. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a high-stability temperature-compensated quartz crystal oscillator that can reduce the difference between the temperature sensed by the compensation chip and the ambient temperature of the quartz crystal, provide a precise temperature compensation frequency, and achieve high frequency stability during temperature transients. It also designs a quartz crystal with a corner structure, which can effectively improve the working stability of the quartz crystal through the dual effects of the corner structure and the isolation through-hole.

[0005] The technical solution adopted by this utility model to solve its technical problem is as follows: a high-stability temperature-compensated quartz crystal oscillator is provided, including a crystal base and a lower ceramic base stacked on top of each other. The lower part of the crystal base has an upper groove in which a compensation chip is installed. The upper part of the lower ceramic base has a lower groove in which a quartz chip is installed. The upper groove and the lower groove are joined together to form an inner cavity. The quartz chip includes a quartz wafer and an electrode surface. The quartz wafer is composed of a fixed segment wafer and a rotating segment wafer. One end of the fixed segment wafer is provided with a bent rotating segment wafer. The upper and lower surfaces of the rotating segment wafer are completely covered with an electrode surface. The electrode surface overlaps with the upper and lower surfaces of the rotating segment wafer to form the main vibration zone. The side of the fixed segment wafer is provided with electrode feet that are connected to the two electrode surfaces one by one. The fixed segment wafer and / or the rotating segment wafer are provided with partition through holes. The bottom of the lower ceramic base is provided with an external electrode that is connected to the compensation chip. The front and rear sides of the lower ceramic base are provided with side electrodes that are connected to the quartz chip and the compensation chip respectively.

[0006] As a supplement to the technical solution described in this utility model, the crystal base includes a crystal base substrate and a crystal base wall. A ring of crystal base wall is arranged at the lower edge of the crystal base substrate. The lower ceramic base includes a ceramic substrate and a ceramic frame wall. A ring of ceramic frame wall is arranged at the upper edge of the ceramic substrate. The ceramic frame wall and the crystal base wall are sealed and fixed by a sealing material.

[0007] As a supplement to the technical solution described in this utility model, the crystal base substrate and the crystal base wall are integrally formed and are etched together by crystal slab etching.

[0008] As a supplement to the technical solution described in this utility model, the upper end of the ceramic frame wall is provided with a V-shaped groove, and the lower end of the crystal base wall is provided with a protrusion that cooperates with the V-shaped groove. The V-shaped groove and the protrusion are sealed and fixed by a sealing material.

[0009] As a supplement to the technical solution described in this utility model, the sealing material is selected from gold-tin alloy, glass glue, or epoxy resin.

[0010] As a supplement to the technical solution described in this utility model, two connecting electrode portions are arranged side by side on the upper end of the ceramic substrate within the wall of the ceramic frame component. The quartz chip is mounted on the two connecting electrode portions by conductive adhesive, and the two connecting electrode portions are respectively connected to the corresponding side electrodes.

[0011] As a supplement to the technical solution described in this utility model, a pillow seat is provided at the upper end of the ceramic substrate below the free end of the turning segment wafer. The pillow seat is used to buffer and support the free end of the quartz chip.

[0012] As a supplement to the technical solution described in this utility model, the lower end of the crystal base substrate is provided with multiple upper electrodes located inside the crystal base wall. These upper electrodes are connected to the compensation chip via bonding wires, and the multiple upper electrodes are respectively connected to the external electrodes and the side electrodes.

[0013] As a supplement to the technical solution described in this utility model, the spacing between the quartz chip and the compensation chip is controlled between 20um and 100um.

[0014] Beneficial effects: This utility model relates to a high-stability temperature-compensated quartz crystal oscillator, which has the following advantages:

[0015] 1. Using a crystal base instead of a traditional metal cover can avoid thermal frequency drift caused by temperature conduction (this problem is improved when the compensation chip and the crystal chip are in the same cavity); some also use a ceramic base instead of a traditional metal cover. Compared with a ceramic base, crystal has higher hardness and can be made very flat, while ceramic base will warp and the entire surface is not flat enough. This can avoid bonding problems caused by uneven base when ultrasonically welding the compensation chip and the crystal base.

[0016] 2. Using etching to fabricate the crystal base can effectively avoid base warping issues and improve the transfer rate and IC cracking problems when the base is combined with the IC; at the same time, the V-shaped design between the crystal base and the lower ceramic base can effectively prevent misalignment when the upper and lower structures are sealed.

[0017] 3. The original long plate-shaped quartz wafer structure has been improved. The improved quartz wafer is an irregularly shaped quartz wafer with a corner structure. The irregularly shaped quartz wafer consists of a fixed segment wafer and a turning segment wafer. A bent turning segment wafer is set at one end of the fixed segment wafer, forming a corner structure between the fixed segment wafer and the turning segment wafer. The upper and lower surfaces of the turning segment wafer are completely covered with an electrode surface. This electrode surface overlaps with the upper and lower surfaces of the turning segment wafer to form the main vibration zone. The electrode feet on the fixed segment wafer are fixed with conductive adhesive. Due to the corner structure, the stress at the conductive adhesive fixing position and the main vibration zone are prevented from being directly applied to the main vibration zone, reducing the impact of stress on the main vibration zone. Moreover, at least one isolation through hole is set between the stress at the conductive adhesive fixing position and the main vibration zone as a stress isolation, which can also significantly reduce the interference of stress on the main vibration zone. Under the dual effect of the corner structure and the isolation through hole, the working stability of the quartz wafer can be effectively improved. Attached Figure Description

[0018] Figure 1 This is a sectional view of the present invention from the main viewing direction;

[0019] Figure 2 This is a top view of the present invention after the crystal base has been removed;

[0020] Figure 3 This is a bottom view of the crystal base described in this utility model;

[0021] Figure 4 This is a bottom view of the lower ceramic base described in this utility model;

[0022] Figure 5 This is a top view of the lower ceramic base described in this utility model;

[0023] Figure 6 This is a top view of the quartz chip described in this utility model;

[0024] Figure 7 This is a stress simulation diagram of the quartz chip described in this utility model.

[0025] Illustration: 1. Crystal base, 2. Sealing material, 3. Lower ceramic base, 4. Quartz chip, 5. Connecting electrode part, 6. Compensation chip, 7. Upper electrode, 8. Bonding wire, 9. Conductive post, 10. Conductive adhesive, 11. Crystal base substrate, 12. Crystal base wall, 13. Ceramic frame wall, 14. Ceramic substrate, 15. Pillow seat, 16. External electrode, 17. Electrode foot, 18. Side electrode, 19. Circuit, 20. Inner cavity, 21. Protrusion, 22. V-shaped groove, 23. Turning segment wafer, 24. Turning segment wafer, 25. Isolation through hole, 26. Electrode surface, 27. Chamfer. Detailed Implementation

[0026] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0027] The embodiments of this utility model relate to a highly stable temperature-compensated quartz crystal oscillator, such as... Figure 1-7As shown, the device includes a crystal base 1 and a lower ceramic base 3 stacked vertically. The crystal base 1 has an upper groove at its lower part, in which a compensation chip 6 is installed. The lower ceramic base 3 has a lower groove at its upper part, in which a quartz chip 4 is installed. The upper and lower grooves are joined together to form an inner cavity 20. The quartz chip 4 includes a quartz wafer and an electrode surface 26. The quartz wafer is composed of a fixed segment wafer 23 and a rotating segment wafer 24. One end of the fixed segment wafer 23 is provided with a bent rotating segment wafer 24. Both the upper and lower surfaces are completely covered with a layer of electrode surface 26. The electrode surface 26 overlaps with the upper and lower surfaces of the steering segment wafer 24 to form the main vibration zone. The side of the fixed segment wafer 23 is provided with electrode feet 17 that are connected to the two electrode surfaces 26 one by one. The fixed segment wafer 23 and / or the steering segment wafer 24 are provided with isolation through holes 25. The bottom of the lower ceramic base 3 is provided with an external electrode 16 that is connected to the compensation chip 6. The front and rear sides of the lower ceramic base 3 are provided with side electrodes 18 that are connected to the quartz chip 4 and the compensation chip 6 respectively.

[0028] This invention uses a crystal base 1 instead of a traditional metal cover to avoid thermal frequency drift caused by temperature conduction (the problem is improved when the compensation chip 6 and the crystal chip 4 are in the same cavity); some also use a ceramic base instead of a traditional metal cover. Compared with a ceramic base, the crystal base 1 has higher hardness and can be made very flat, while the ceramic base will warp and the entire surface is not flat enough. This way, when the compensation chip 6 and the crystal base 1 are ultrasonically welded, the bonding problem caused by the unevenness of the base can be avoided.

[0029] This invention places the compensation chip 6 and the quartz chip 4 inside the same cavity 20. One of the functions of the compensation chip 6 is to monitor the temperature. In this way, the temperature monitored by the compensation chip 6 is the same as the temperature of the quartz chip 4 inside the same cavity 20, so that the temperature sensed by the two is consistent, improving the compensation accuracy and ensuring the stability of the frequency change of the quartz chip 4 when the temperature changes.

[0030] This invention further improves the original long plate-shaped quartz wafer structure. The improved quartz wafer is an irregularly shaped quartz wafer with a corner structure. The irregularly shaped quartz wafer consists of a fixed segment wafer 23 and a turning segment wafer 24. One end of the fixed segment wafer 23 is provided with a bent turning segment wafer 24, forming a corner structure between the fixed segment wafer 23 and the turning segment wafer 24. The upper and lower surfaces of the turning segment wafer 24 are completely covered with a layer of electrode surface 26. This electrode surface 26 overlaps with the upper and lower surfaces of the turning segment wafer 24 to form the main vibration zone. The electrode feet 17 on the fixed segment wafer 23 are fixed with conductive adhesive. The corner structure prevents stress from directly acting on the main vibration area, reducing its impact. Furthermore, at least one through-hole 25 acts as a stress barrier between the conductive adhesive fixing point and the main vibration area, significantly reducing stress interference. The combined effect of the corner structure and the through-hole 25 effectively improves the stability of the quartz wafer. The through-hole 25 is generally preferably rectangular. Chamfers 27 are provided at both corners of the free end of the turning section wafer 24 to reduce impact damage.

[0031] As a structural description of the crystal base 1 and the lower ceramic base 3, the crystal base 1 includes a crystal base substrate 11 and a crystal base wall 12. A ring of crystal base wall 12 is arranged around the lower edge of the crystal base substrate 11. The lower ceramic base 3 includes a ceramic substrate 14 and a ceramic frame wall 13. A ring of ceramic frame wall 13 is arranged around the upper edge of the ceramic substrate 14. The ceramic frame wall 13 and the crystal base wall 12 are sealed and fixed by a sealing material 2.

[0032] As an explanation of the encapsulation of the crystal base 1 and the lower ceramic base 3, the sealing material 2 is used to seal and fix the ceramic frame wall 13 and the crystal base wall 12 by heating and melting. This sealing material 2 can be a gold-tin alloy, glass glue, or epoxy resin.

[0033] The crystal base substrate 11 and the crystal base wall 12 are integrally formed and are etched together by crystal slab etching.

[0034] As a connecting structure between the ceramic frame wall 13 and the crystal base wall 12, the upper end of the ceramic frame wall 13 is provided with a V-shaped groove 22, and the lower end of the crystal base wall 12 is provided with a protrusion 21 that cooperates with the V-shaped groove 22. The V-shaped groove 22 and the protrusion 21 are sealed and fixed by a sealing material 2. By the upper and lower mating cooperation between the V-shaped groove 22 and the protrusion 21, the positional displacement when the crystal base 1 and the lower ceramic base 3 are sealed can be reduced, thereby improving the strength of the connection.

[0035] As an instruction for mounting the quartz wafer 4, two connecting electrode portions 5 are arranged side by side on the upper end of the ceramic substrate 14 within the ceramic frame wall 13. The two connecting electrode portions 5 correspond to the two electrode feet 17 on the quartz wafer 4. The quartz wafer 4 is mounted on the two connecting electrode portions 5 by conductive adhesive 10. The connecting electrode portions 5 and the electrode feet 17 are fixed and connected by conductive adhesive 10. The two connecting electrode portions 5 are connected to the corresponding side electrodes 18.

[0036] As an explanation of the buffering and support scheme for the quartz chip 4, a pillow seat 15 is provided at the upper end of the ceramic substrate 14 below the free end of the turning segment wafer 24. The pillow seat 15 is used to buffer and support the free end of the quartz chip 4.

[0037] As an explanation of the installation and corresponding connection of the compensation chip 6, multiple upper electrodes 7 are arranged at the lower end of the crystal base substrate 11 within the crystal base wall 12. These upper electrodes 7 are connected to the compensation chip 6 via bonding wires 8. The multiple upper electrodes 7 are respectively connected to the external electrodes 16 and the side electrodes 18. The compensation chip 6 has a total of six terminals. Six upper electrodes 7 are distributed at the lower end of the crystal base substrate 11, corresponding to the six terminal positions of the compensation chip 6. The upper electrodes 7 and the terminals are combined via bonding wires 8 to firmly fix the compensation chip 6 under the crystal base substrate 11. An external electrode 16 is provided at each of the four corners of the bottom of the lower ceramic base 3. Four of the upper electrodes 7 are respectively connected to the four external electrodes 16 via conductive posts 9. The remaining two upper electrodes 7 are guided to the upper surface of the ceramic substrate 14 via conductive posts 9. Then, the lower ends of the two conductive posts 9 and the two electrode feet 17 are connected to the corresponding side electrodes 18 via lines 19 (see Figure 5).

[0038] The spacing between the quartz chip 4 and the compensation chip 6 is controlled between 20um and 100um.

[0039] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0040] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0041] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0042] The above provides a detailed description of a high-stability temperature-compensated quartz crystal oscillator provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A high-stability temperature-compensated quartz crystal oscillator comprising a quartz base (1) and a lower ceramic base (3) stacked one on top of the other, characterized in that: The crystal base (1) has an upper groove at its lower part, in which a compensation chip (6) is installed. The lower ceramic base (3) has a lower groove at its upper part, in which a quartz chip (4) is installed. The upper groove and the lower groove are joined together to form an inner cavity (20). The quartz chip (4) includes a quartz wafer and an electrode surface (26). The quartz wafer is composed of a fixed segment wafer (23) and a turning segment wafer (24). One end of the fixed segment wafer (23) is provided with a bent turning segment wafer (24). The upper and lower surfaces of the turning segment wafer (24) are completely covered with an electrode surface. (26) The electrode surface (26) overlaps with the upper and lower surfaces of the steering segment wafer (24) to form the main vibration zone. The side of the fixed segment wafer (23) is provided with electrode feet (17) that are connected to the two electrode surfaces (26) one by one. The fixed segment wafer (23) and / or the steering segment wafer (24) are provided with partition through holes (25). The bottom of the lower ceramic base (3) is provided with an external electrode (16) that is connected to the compensation chip (6). The front and rear sides of the lower ceramic base (3) are provided with side electrodes (18) that are connected to the quartz chip (4) and the compensation chip (6).

2. The high-stability temperature-compensated quartz crystal oscillator of claim 1, wherein: The angle between the fixed segment wafer (23) and the turning segment wafer (24) is between 145 degrees and 155 degrees.

3. The high-stability temperature-compensated quartz crystal oscillator according to claim 1, characterized in that: The crystal base (1) includes a crystal base substrate (11) and a crystal base wall (12). A ring of crystal base wall (12) is arranged on the lower edge of the crystal base substrate (11). The lower ceramic base (3) includes a ceramic substrate (14) and a ceramic frame wall (13). A ring of ceramic frame wall (13) is arranged on the upper edge of the ceramic substrate (14). The ceramic frame wall (13) and the crystal base wall (12) are sealed and fixed by a sealing material (2).

4. A high-stability temperature-compensated quartz crystal oscillator according to claim 3, characterized in that: The crystal base substrate (11) and the crystal base wall (12) are integrally formed and are formed by etching crystal wafers.

5. A high-stability temperature-compensated quartz crystal oscillator according to claim 3, characterized in that: The ceramic frame wall (13) has a V-shaped groove (22) at the upper end, and the crystal base wall (12) has a protrusion (21) at the lower end that cooperates with the V-shaped groove (22). The V-shaped groove (22) and the protrusion (21) are sealed and fixed by a sealing material (2).

6. A high-stability temperature-compensated quartz crystal oscillator according to claim 3 or 5, characterized in that: The sealing material (2) is selected from gold-tin alloy, glass glue, or epoxy resin.

7. A high-stability temperature-compensated quartz crystal oscillator according to claim 3, characterized in that: The upper end of the ceramic substrate (14) is located inside the ceramic frame wall (13) with two connecting electrode parts (5) arranged side by side. The quartz chip (4) is mounted on the two connecting electrode parts (5) by conductive adhesive (10). The two connecting electrode parts (5) are respectively connected to the corresponding side electrode (18).

8. A high-stability temperature-compensated quartz crystal oscillator according to claim 3, characterized in that: A pillow seat (15) is provided on the upper end of the ceramic substrate (14) below the free end of the turning segment wafer (24).

9. A high-stability temperature-compensated quartz crystal oscillator according to claim 3, characterized in that: The lower end of the crystal base substrate (11) is located inside the crystal base wall (12) and has multiple upper electrodes (7). The upper electrodes (7) are connected to the compensation chip (6) through bonding wires (8). The multiple upper electrodes (7) are respectively connected to the external electrode (16) and the side electrode (18).

10. A high-stability temperature-compensated quartz crystal oscillator according to claim 1, characterized in that: The spacing between the quartz chip (4) and the compensation chip (6) is controlled between 20um and 100um.

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