High-stability temperature compensation quartz crystal oscillator

Abstract

The invention relates to a high-stability temperature compensation quartz crystal oscillator which comprises a crystal base and a lower ceramic base which are stacked up and down, an upper groove is formed in the lower portion of the crystal base, a compensation chip is installed in the upper groove, a lower groove is formed in the upper portion of the lower ceramic base, a quartz chip is installed in the lower groove, and the quartz chip is installed in the lower groove. The quartz chip comprises an upper groove and a lower groove, the upper groove and the lower groove are butted and spliced up and down to form an inner cavity, the quartz chip comprises a quartz wafer, the quartz wafer is composed of a fixed section wafer and a turning section wafer, and one end of the fixed section wafer is provided with a bent turning section wafer. According to the invention, the difference between the temperature sensed by the compensation chip and the ambient temperature of the quartz wafer can be reduced, the accurate temperature compensation frequency is provided, and the high stability of the frequency during temperature transient change is achieved; in addition, the quartz wafer with a corner structure is also designed, and the working stability of the quartz wafer can be effectively improved under the dual effects of the corner structure and the partition through hole.

Description

Technical Field

[0001] The present invention relates to the technical field of quartz crystal frequency components, in particular to a high-stability temperature-compensated quartz crystal oscillator. Background Art

[0002] A temperature-compensated quartz crystal oscillator typically consists of a piezoelectric quartz crystal, a compensation chip, conductive adhesive, a ceramic base, and a metal cover. The piezoelectric quartz crystal is typically rectangular or circular, and the package base typically has a recessed groove on the back for the compensation chip. Electrodes are plated on the top and bottom surfaces of the piezoelectric quartz crystal and secured to the base with conductive adhesive. AC voltage is applied through pins to the compensation chip and the upper and lower electrodes of the quartz crystal, causing the quartz crystal to produce an inverse piezoelectric effect, resulting in oscillations. Simultaneously, the compensation chip senses the ambient temperature and adjusts the voltage accordingly to compensate for the product's output frequency. The compensated output frequency is relatively stable.

[0003] The continuous development of electronic products, especially GPS and satellite communications, has led to more stringent requirements for temperature-compensated quartz crystal oscillators. Currently, the compensation chip and quartz crystal wafer in most quartz crystal oscillators 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 transmitted to the quartz wafer through the ceramic base and conductive adhesive. This causes the compensation chip to deviate from the compensated frequency. Consequently, the final output frequency cannot keep pace with the temperature change, resulting in a hysteresis effect and product anomalies. When customers test the board, the frequency fluctuates significantly, leading to unstable connections or disconnections. Furthermore, traditional temperature-compensated quartz crystal oscillators use a metal top cover or ceramic base as the top cover structure, which has relatively poor flatness. This makes it prone to offset during sealing and welding, and thermal frequency drift due to temperature conduction problems. Finally, the impact of factors such as stress on the quartz wafer must also be considered. Therefore, it is necessary to design a high-stability temperature-compensated quartz crystal oscillator to address the above issues. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high-stability temperature-compensated quartz crystal oscillator, which can reduce the difference between the temperature sensed by the compensation chip and the ambient temperature of the quartz wafer, provide accurate temperature compensation frequency, and achieve high frequency stability during temperature transients; a quartz wafer with a corner structure is also designed, and the dual effects of the corner structure and the isolation through-hole can effectively improve the working stability of the quartz wafer.

[0005] The technical solution adopted by the present invention to solve its technical problems is: to provide a high-stability temperature-compensated quartz crystal oscillator, including a crystal base and a lower ceramic base stacked up and down, the crystal base having an upper groove at the bottom, a compensation chip installed in the upper groove, the lower ceramic base having a lower groove at the top, a quartz chip installed in the lower groove, the upper groove and the lower groove being butted and spliced ​​up and down to form an inner cavity, the quartz chip including a quartz wafer and an electrode surface, the quartz wafer consisting of a fixed section wafer and a turning section wafer, one end of the fixed section wafer being provided with a bent turning section wafer, the upper and lower surfaces of the turning section wafer being completely covered with a layer of electrode surface, the electrode surface overlapping with the upper and lower surfaces of the turning section wafer forming a main vibration region, the side edges of the fixed section wafer being provided with electrode pins connected to the two electrode surfaces in a one-to-one correspondence, the fixed section wafer and / or the turning section wafer being provided with a partition through-hole, the bottom of the lower ceramic base being provided with an external electrode connected to the compensation chip, and the front and rear sides of the lower ceramic base being provided with side electrodes connected to the quartz chip and the compensation chip.

[0006] As a supplement to the technical solution described in the present invention, the crystal base includes a crystal base substrate and a crystal base wall, and a circle of crystal base wall is arranged on the lower edge of the crystal base substrate. The lower ceramic base includes a ceramic substrate and a ceramic frame wall, and a circle of ceramic frame wall is arranged on 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 the present invention, the crystal base substrate and the crystal base wall are integrally formed and the whole is formed by etching a crystal piece.

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

[0009] As a supplement to the technical solution of the present invention, the sealing material is selected from gold-tin alloy, glass glue or epoxy resin.

[0010] As a supplement to the technical solution described in the present invention, the upper end of the ceramic substrate is located inside the wall of the ceramic frame and has two connecting electrode parts arranged side by side. The quartz chip is mounted on the two connecting electrode parts through conductive glue, and the two connecting electrode parts are respectively connected to the corresponding side electrodes.

[0011] As a supplement to the technical solution described in the present invention, a pillow seat is provided at the upper end of the ceramic substrate below the free end of the turning section chip, and the pillow seat is used to cushion and support the free end of the quartz chip.

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

[0013] As a supplement to the technical solution of the present invention, the distance between the quartz chip and the compensation chip is controlled to be between 20um and 100um.

[0014] Beneficial effects: The present invention 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 problems (the compensation chip and the crystal chip are in the same cavity to improve this problem); some also use a ceramic base instead of a traditional metal cover. Compared with the ceramic base, the crystal base has a higher hardness and can be made very flat, while the ceramic base may warp and the entire surface is not flat. In this way, when ultrasonic welding the compensation chip and the crystal base, the bonding problems caused by the uneven base can be avoided;

[0016] 2. Using etching to make the crystal base can effectively avoid the base warping problem, improve the transfer rate when the base is combined with the IC, and prevent IC cracking. At the same time, the V-shaped design between the crystal base and the lower ceramic base can effectively avoid the offset phenomenon when the upper and lower structures are sealed.

[0017] 3. The original long plate-shaped quartz wafer structure is also improved. The improved quartz wafer is a special-shaped quartz wafer with a corner structure. The special-shaped quartz wafer consists of a fixed section wafer and a turning section wafer. A bent turning section wafer is set at one end of the fixed section wafer. A corner structure is formed between the fixed section wafer and the turning section wafer. The upper and lower surfaces of the turning section wafer are all covered with a layer of electrode surface. The electrode surface overlaps with the upper and lower surfaces of the turning section wafer to form a main vibration area. The electrode feet on the fixed section wafer are fixed positions of the conductive glue. Due to the existence of the corner structure, the stress at the fixed position of the conductive glue and the main vibration area is avoided from directly acting on the main vibration area, thereby reducing the influence of stress on the main vibration area; and at least one partition through hole is set between the stress at the fixed position of the conductive glue and the main vibration area as a stress partition, which can also greatly reduce the interference of stress on the main vibration area. Under the dual effects of the corner structure and the partition through hole, the working stability of the quartz wafer can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional view of the main viewing direction of the present invention;

[0019] Figure 2 This is a top view of the present invention without the crystal base;

[0020] Figure 3 is a bottom view of the crystal base of the present invention;

[0021] Figure 4 is a bottom view of the lower ceramic base of the present invention;

[0022] Figure 5 is a top view of the lower ceramic base of the present invention;

[0023] Figure 6 is a top view of the quartz chip of the present invention;

[0024] Figure 7 This is a stress simulation diagram of the quartz chip described in the present invention.

[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 column, 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. Line, 20. Inner cavity, 21. Raised part, 22. V-shaped groove, 23. Turning section chip, 24. Turning section chip, 25. Partitioning through hole, 26. Electrode surface, 27. Chamfer. DETAILED DESCRIPTION

[0026] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0027] The embodiment of the present invention relates to a high stability temperature compensated quartz crystal oscillator, such as Figure 1-7As shown, it includes a crystal base 1 and a lower ceramic base 3 stacked up and down, the crystal base 1 has an upper groove at the bottom, and a compensation chip 6 is installed in the upper groove. The lower ceramic base 3 has a lower groove at the top, and a quartz chip 4 is installed in the lower groove. The upper groove and the lower groove are connected and spliced ​​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 steering segment wafer 24. The fixed segment wafer 23 is provided with a bent steering segment wafer 24 at one end. The steering segment wafer 24 is provided with a bent steering segment wafer 24. Both the upper and lower surfaces are completely covered with a layer of electrode surface 26, which overlaps with the upper and lower surfaces of the steering section chip 24 to form a main vibration area. The side of the fixed section chip 23 is provided with electrode feet 17 connected to the two electrode surfaces 26 in a one-to-one correspondence. The fixed section chip 23 and / or the steering section chip 24 are provided with a partition through hole 25. The bottom of the lower ceramic base 3 is provided with an external electrode 16 connected to the compensation chip 6, and the front and rear sides of the lower ceramic base 3 are provided with side electrodes 18 connected to the quartz chip 4 and the compensation chip 6.

[0028] The present invention uses a crystal base 1 instead of a traditional metal cover to avoid thermal frequency drift caused by temperature conduction (this problem can be improved by placing the compensation chip 6 and the crystal chip 4 in the same cavity). Some also use a ceramic base instead of a traditional metal cover. Compared with the ceramic base, the crystal base 1 has a higher hardness and can be made very flat, while the ceramic base may warp and the entire surface is not flat. In this way, when ultrasonically welding the compensation chip 6 and the crystal base 1, bonding problems caused by the uneven base can be avoided.

[0029] The present invention arranges the compensation chip 6 and the quartz chip 4 inside the same inner cavity 20. One of the functions of the compensation chip 6 is to monitor temperature. In this way, the temperature monitored by the compensation chip 6 in the same inner cavity 20 is equivalent to the temperature of the quartz chip 4, so that the temperatures sensed by the two remain consistent, thereby improving the compensation accuracy and ensuring the stability of the frequency change of the quartz chip 4 when the temperature changes.

[0030] The present invention also improves the original long plate-shaped quartz wafer structure. The improved quartz wafer is a special-shaped quartz wafer with a corner structure. The special-shaped quartz wafer consists of a fixed segment wafer 23 and a turning segment wafer 24. A bent turning segment wafer 24 is provided at one end of the fixed segment wafer 23. A corner structure is formed between the fixed segment wafer 23 and the turning segment wafer 24. The upper and lower surfaces of the turning segment wafer 24 are all covered with a layer of electrode surface 26. The electrode surface 26 overlaps with the upper and lower surfaces of the turning segment wafer 24 to form a main vibration area. The electrode foot 17 on the fixed segment wafer 23 is a conductive glue fixing position. The conductive glue fixing position Due to the existence of the corner structure between the stress at the fixed position of the conductive adhesive and the main vibration area, the stress is prevented from directly acting on the main vibration area, thereby reducing the influence of the stress on the main vibration area; and at least one partition hole 25 is provided between the stress at the fixed position of the conductive adhesive and the main vibration area as a stress partition, which can also greatly reduce the interference of the stress on the main vibration area. Under the dual effects of the corner structure and the partition hole 25, the working stability of the quartz wafer can be effectively improved; the partition hole 25 is generally preferably a rectangular through hole; chamfers 27 are provided at the corners on both sides of the free end of the turning section wafer 24, and the chamfers 27 are provided to reduce the damage to the turning section wafer 24 caused by collision.

[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, and a circle 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, and a circle 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.

[0032] As a packaging description of the crystal base 1 and the lower ceramic base 3, the sealing material 2 is heated and melted to seal and fix the ceramic frame wall 13 and the crystal base wall 12. The sealing material 2 can be a gold-tin alloy, glass glue or epoxy resin glue.

[0033] The crystal base substrate 11 and the crystal base wall 12 are integrally formed and are formed as a whole by etching a crystal sheet.

[0034] As a connection structure between the ceramic frame wall 13 and the crystal base wall 12, a V-shaped groove 22 is provided at the upper end of the ceramic frame wall 13, and a raised portion 21 is provided at the lower end of the crystal base wall 12 to cooperate with the V-shaped groove 22. The V-shaped groove 22 and the raised portion 21 are sealed and fixed by the sealing material 2; by the upper and lower docking cooperation between the V-shaped groove 22 and the raised portion 21, the positional deviation of the crystal base 1 and the lower ceramic base 3 when sealed can be reduced, thereby improving the strength of the combination.

[0035] As an installation instruction for the quartz chip 4, the upper end of the ceramic substrate 14 is located inside the ceramic frame wall 13 and has two connecting electrode parts 5 arranged side by side. The two connecting electrode parts 5 correspond to the two electrode pins 17 on the quartz chip 4 respectively. The quartz chip 4 is mounted on the two connecting electrode parts 5 through the conductive glue 10. The connecting electrode parts 5 and the electrode pins 17 are fixed and connected through the conductive glue 10. The two connecting electrode parts 5 are respectively connected to the corresponding side electrodes 18.

[0036] As an explanation of the solution for buffering and supporting 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 section wafer 24 . The pillow seat 15 is used to buffer and support the free end of the quartz chip 4 .

[0037] As an illustration of the installation and corresponding connection of the compensation chip 6, the lower end of the crystal base substrate 11 is located within the crystal base wall 12 and is provided with a plurality of upper electrodes 7. The upper electrodes 7 are connected to the compensation chip 6 via bonding wires 8, and the plurality of 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, and six upper electrodes 7 are distributed at the lower end of the crystal base substrate 11. The six upper electrodes 7 correspond to the six terminal positions of the compensation chip 6. The upper electrodes 7 and the terminals are bonded via bonding wires 8, firmly fixing 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, of which four upper electrodes 7 are respectively connected to the four external electrodes 16 via conductive pillars 9. The remaining two upper electrodes 7 are guided to the upper end surface of the ceramic substrate 14 via the conductive pillars 9, and then the lower ends of the two conductive pillars 9 and the two electrode pins 17 are connected to the corresponding side electrodes 18 via lines 19 (see Figure 5).

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

[0039] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

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

[0041] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0042] The above is a detailed introduction to a high-stability temperature-compensated quartz crystal oscillator provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A high-stability temperature-compensated quartz crystal oscillator, comprising a crystal base (1) and a lower ceramic base (3) stacked one above the other, characterized in that: The crystal base (1) has an upper groove at the bottom, in which a compensation chip (6) is installed. The lower ceramic base (3) has a lower groove at the top, in which a quartz chip (4) is installed. The upper groove and the lower groove are connected and spliced ​​up and down 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 section wafer (23) and a steering section wafer (24). A bent steering section wafer (24) is provided at one end of the fixed section wafer (23). The upper and lower surfaces of the steering section wafer (24) are all covered with a layer of electrode surface. (26), the electrode surface (26) overlaps with the upper and lower surfaces of the steering section chip (24) to form a main vibration area, the side of the fixed section chip (23) is provided with an electrode foot (17) connected to the two electrode surfaces (26) in a one-to-one correspondence, the fixed section chip (23) and / or the steering section chip (24) are provided with a partition through hole (25), the bottom of the lower ceramic base (3) is provided with an external electrode (16) connected to the compensation chip (6), and the front and rear sides of the lower ceramic base (3) are provided with side electrodes (18) connected to the quartz chip (4) and the compensation chip (6).

2. The high-stability temperature-compensated quartz crystal oscillator according to claim 1, characterized in that: The angle between the fixed section chip (23) and the turning section chip (24) ranges from 145 degrees to 155 degrees.

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

4. The 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 the whole is formed by etching a crystal sheet.

5. The high-stability temperature-compensated quartz crystal oscillator according to claim 3, characterized in that: 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 raised portion (21) that matches the V-shaped groove (22). The V-shaped groove (22) and the raised portion (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. The 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) and has two connecting electrode parts (5) arranged in parallel. The quartz chip (4) is mounted on the two connecting electrode parts (5) through a conductive adhesive (10). The two connecting electrode parts (5) are respectively connected to corresponding side electrodes (18).

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

9. The 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 is provided with a plurality of upper electrodes (7). The upper electrodes (7) are connected to the compensation chip (6) via bonding wires (8). The plurality of upper electrodes (7) are respectively connected to the external electrodes (16) and the side electrodes (18).

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

Images