阅读说明：本技术 一种采用条形补偿膜应力补偿的晶体谐振器 (Crystal resonator adopting strip-shaped compensation film for stress compensation ) 是由 苗苗 李智奇 冯娜娜 李皖 周渭 张艺 于 2020-03-30 设计创作，主要内容包括：本发明涉及晶体谐振器,特别是一种采用条形补偿膜应力补偿的晶体谐振器,其特征是：至少包括：晶体,所述的晶体为圆片形；与圆片形晶体同心且小于圆片形晶体的直径有一中心电极,中心电极镀膜在晶体的上下表面上；沿晶体的直径方向在中心电极的两侧有延伸层；两侧的延伸层各延伸至一个扇形面,扇形面的中心线与延伸层中心线重合；在中心电极上有补偿膜,补偿膜为长方形,补偿膜的长度方向与延伸层中心线垂直；长方形补偿膜长度方向与晶体片x轴方向一致。它提供了一种结构简单、体积更小、功耗更低、稳定度更高、成本较低的采用条形补偿膜应力补偿晶体谐振器。(The invention relates to a crystal resonator, in particular to a crystal resonator adopting strip compensation film stress compensation, which is characterized in that: at least comprises the following steps: the crystal is in a disc shape; a central electrode concentric with the wafer-shaped crystal and having a diameter smaller than that of the wafer-shaped crystal, the central electrode being coated on the upper and lower surfaces of the crystal; extending layers are arranged on two sides of the central electrode along the diameter direction of the crystal; the extension layers on the two sides respectively extend to a sector, and the central line of the sector is superposed with the central line of the extension layer; a compensation film is arranged on the central electrode, the compensation film is rectangular, and the length direction of the compensation film is vertical to the central line of the extension layer; the length direction of the rectangular compensation film is consistent with the x-axis direction of the crystal wafer. The crystal resonator adopting the strip-shaped compensation film stress compensation is simple in structure, smaller in size, lower in power consumption, higher in stability and lower in cost.)

1. A crystal resonator adopting stress compensation of a strip-shaped compensation film is characterized in that: at least comprises the following steps: the crystal (1), the said crystal (1) is the disc shape; a central electrode (2) which is concentric with the wafer-shaped crystal (1) and is smaller than the diameter of the wafer-shaped crystal (1), and the central electrode (2) is coated on the upper surface and the lower surface of the crystal (1); extending layers (3) are arranged on two sides of the central electrode (2) along the diameter direction of the crystal (1); the extension layers (3) on the two sides respectively extend to a sector (4), and the central line (5) of the sector is superposed with the central line of the extension layer (3); a compensation film (6) is arranged on the central electrode, the compensation film (6) is rectangular, and the length direction of the compensation film (6) is vertical to the central line of the extension layer (3); the length direction of the rectangular compensation film (6) is defined as an x axis; according to the force-frequency characteristic of the crystal, when a pressure force is applied to the central electrode (2) in the x-axis direction, the frequency of the crystal is raised and deviates upwards from the nominal frequency; when a pulling force is applied to the x-axis direction of the central electrode (2), the frequency of the crystal is pulled down, and the nominal frequency is shifted downwards; when the acting force is larger, the caused frequency offset is larger, and the force magnitude and the frequency offset are in a direct proportion relation; therefore, when the temperature rises and is higher than the room temperature, because the thermal expansion coefficient of the compensation film (6) is larger than that of the central electrode (2), the expansion amplitude of the compensation film (6) is larger than that of the central electrode at the moment, and similarly, when the temperature is lower than the room temperature, the contraction amplitude of the compensation film (6) is larger than that of the central electrode (2).

2. The crystal resonator adopting the strip compensation film stress compensation as claimed in claim 1, wherein: the diagonal length of the rectangular compensation film (6) is smaller than the diameter of the central electrode.

3. The crystal resonator adopting the strip compensation film stress compensation as claimed in claim 1, wherein: the intersection point of two diagonal lines of the compensation film (6) is positioned on the center electrode and the center (7) of the compensation film.

4. The crystal resonator adopting the strip compensation film stress compensation as claimed in claim 1, wherein: the width of the extension layer (3) is less than the arc length of the inner side of the sector (4).

5. The crystal resonator adopting the strip compensation film stress compensation as claimed in claim 1, wherein: the diameter of the central electrode (2) is smaller than 1/2 of the diameter of the crystal (1).

6. The crystal resonator adopting the strip compensation film stress compensation as claimed in claim 1, wherein: the length direction of the rectangular compensation film (6) is vertical to the central lines of the two fan-shaped surfaces (4).

7. The crystal resonator adopting the strip compensation film stress compensation as claimed in claim 1, wherein: the central electrode (2) and the compensation film (6) are made of two different metal materials, and the thermal expansion coefficient of the compensation film (6) is larger than that of the central electrode (2).

8. The crystal resonator adopting the strip compensation film stress compensation as claimed in claim 7, wherein: the material of the compensation film (6) is silver, and the material of the central electrode (2) is gold.

9. The crystal resonator adopting the strip compensation film stress compensation as claimed in claim 1, wherein: the compensation film (6) is attached to the central electrode (2).

10. The crystal resonator adopting the strip compensation film stress compensation as claimed in claim 1, wherein: the compensation film (6) is plated in the central area of the crystal (1).

Technical Field

The invention relates to a crystal resonator, in particular to a crystal resonator adopting strip-shaped compensation film stress compensation.

Background

The crystal resonator is a frequency source device widely applied, and is widely applied to a plurality of fields such as communication, navigation, medical treatment, national defense and the like due to the characteristics of low cost and high stability. With the further development of communication industries, the demand for high-stability crystal resonators is gradually expanding. Meanwhile, higher requirements are also placed on performance indexes of the crystal resonator, and a frequency source device with smaller volume, lower power consumption, higher stability and lower cost is expected to be obtained. Although the existing chip clock and MEMS oscillator are better than the conventional crystal oscillator in terms of stability, the cost is relatively high, and the large-scale and flow-through production is not easy. Therefore, the frequency source most used in the market at present is still a crystal oscillator. While highly stable crystal oscillators typically use temperature compensated crystal oscillators. The existing method for improving the frequency stability of temperature compensation crystal oscillation mainly modifies a peripheral compensation network and performs frequency compensation on an original frequency signal by using compensation voltage. According to different compensation modes, the method can be divided into three modes of analog, digital and microcomputer compensation. Although the three compensation modes can maintain the frequency stability in the range of minus 50 ℃ to plus 85 ℃ in the range of plus or minus 0.5ppm to plus or minus 1ppm, even if the frequency stability reaches 10 DEG C^-7The magnitude is higher than that of the conventional temperature compensation crystal oscillator, but the three processing modes are all frequency compensation by using a peripheral compensation network, so that the size and the whole volume of original devices in the compensation network limit the development of the temperature compensation crystal oscillator towards miniaturization.

Disclosure of Invention

The invention aims to provide a stress compensation crystal resonator adopting a strip compensation film, which has the advantages of simple structure, smaller volume, lower power consumption, higher stability and lower cost.

The invention aims to realize the purpose, and the crystal resonator adopting the strip compensation film for stress compensation is characterized in that: at least comprises the following steps: the crystal is in a disc shape; a central electrode concentric with the wafer-shaped crystal and having a diameter smaller than that of the wafer-shaped crystal, the central electrode being coated on the upper and lower surfaces of the crystal; extending layers are arranged on two sides of the central electrode along the diameter direction of the crystal; the extension layers on the two sides respectively extend to a sector, and the central line of the sector is superposed with the central line of the extension layer; a compensation film is arranged on the central electrode, the compensation film is rectangular, and the length direction of the compensation film is vertical to the central line of the extension layer; the length direction of the rectangular compensation film is consistent with the x-axis direction of the crystal wafer; according to the force-frequency characteristic of the crystal, when a pressure force is applied to the central electrode in the x-axis direction, the frequency of the crystal is raised and deviates upwards from the nominal frequency; when a pulling force is applied to the x-axis direction of the central electrode, the frequency of the crystal is pulled down, and the nominal frequency is shifted downwards; when the acting force is larger, the caused frequency offset is larger, and the force magnitude and the frequency offset are in a direct proportion relation; therefore, when the temperature rises and is higher than the room temperature, the compensation film has a larger expansion amplitude than the central electrode because the compensation film has a larger thermal expansion coefficient than the central electrode, and similarly, when the temperature is lower than the room temperature, the compensation film has a larger contraction amplitude than the central electrode.

The diagonal length of the strip-shaped compensation film is smaller than the diameter of the central electrode.

The intersection point of two diagonal lines of the compensation film is positioned on the center of the central electrode and the center of the compensation film.

The width of the extension layer is less than the arc length of the inner side of the sector.

The diameter of the central electrode is less than 1/2 of the diameter of the crystal.

The length direction of the rectangular compensation film is vertical to the central lines of the two fan-shaped surfaces.

The central electrode and the compensation film are made of two different materials, and the thermal expansion coefficient of the compensation film is larger than that of the central electrode.

The material of the compensation film is silver, and the material of the central electrode is gold.

The compensation film is attached to the center electrode.

The compensation film is plated in the central area of the crystal.

The principle and the advantages of the invention are as follows: the frequency deviation of the crystal caused by the temperature influence in the actual operation is compensated by the phenomenon that the frequency of the crystal can deviate under the stress action, and the idea is similar to the mode that the peripheral circuit adopts the compensation voltage. The structure adopts a mode of double-layer metal electrodes, and a strip-shaped compensation film made of other materials is additionally plated in the x-axis direction of the central electrode of the traditional electrode. The strip-shaped compensation film is vertically symmetrical, and the center of the strip-shaped compensation film is superposed with the center of the original electrode. The central electrode is provided with two side extension layers which are of a symmetrical structure, the two side extension layers reach the edge of the crystal to form two fan-shaped surfaces, and the central lines of the two fan-shaped surfaces are superposed with the central lines of the two side extension layers.

The compensation film material and the central electrode material are two metal materials with larger difference of thermal expansion coefficients. And requires that the compensation film material have a higher coefficient of thermal expansion than the central electrode region. When the external temperature changes, the two materials can generate expansion deformation phenomena. However, since the two materials are adhered to each other and have a large difference in expansion coefficient, they are different in the degree of thermal expansion at the same temperature. At the moment, mutual extrusion force is generated between the two, and the coating mode can be used as a mode that the compensation film applies force to the central electrode. And the larger the difference between the temperature and the room temperature, the larger the magnitude of the force is. Therefore, the force-frequency characteristic of the crystal can be used, the frequency drift of the crystal along with the temperature is pulled back within the range of minus 50 ℃ to plus 85 ℃ through the compensation effect of the stress on the frequency, and the temperature-frequency characteristic curve is as smooth as possible.

Drawings

The invention is further illustrated with reference to the accompanying drawings of embodiments:

FIG. 1 is a stress compensating crystal slab of the present invention implementing a stripe compensation film;

FIG. 2 is a schematic view of the compensation film and the center electrode expanding with heat and contracting with cold;

FIG. 3 is a stress distribution of a compensation film to a center electrode;

FIG. 4 is a deformation of the center electrode under the stress of the compensation film;

FIG. 5 is a deformation of the center electrode by an equivalent force;

FIG. 6 is a diagram illustrating the effect of the stress compensation temperature frequency characteristic;

figure 7 is a stress compensating crystal resonator manufacturing flow.

In the figure, 1, crystal; 2. a center electrode; 3. an extension layer; 4. a sector; 5. the central lines of the two fan-shaped surfaces; 6. a compensation film; 7. a center electrode and a compensation film center.

Detailed Description

As shown in fig. 1, a crystal resonator using stress compensation of a strip-shaped compensation film is characterized in that: at least comprises the following steps: the crystal 1, the said crystal 1 is a disc-shaped, concentric with crystal 1 of the disc-shaped, and the diameter smaller than crystal 1 of the disc-shaped has a central electrode 2, the central electrode 2 is plated on a surface of the crystal 1, there are extension layers 3 on both sides of the central electrode 2 along the diameter direction of the crystal 1, the extension layer 3 of both sides extend to a sector 4 separately, the central line 5 of the sector 4 coincides with central line of extension layer 3; the central electrode is provided with a compensation film 6, the compensation film 6 is rectangular, and the rectangular direction of the compensation film 6 is vertical to the central line of the extension layer 3.

The rectangular diagonal length of the rectangular compensation film 6 is smaller than the diameter of the central electrode.

The intersection point of two diagonal lines of the compensation film 6 is positioned on the center electrode and the center 7 of the compensation film.

The width of the extension layer is less than the arc length of the inner side of the sector.

The diameter of the central electrode 2 is smaller than the diameter 1/2 of the crystal 1.

The length direction of the rectangular compensation film 6 is vertical to the central lines of the two fan-shaped surfaces.

As shown in fig. 2, it is necessary to define the following for explaining the present invention that the length direction of the rectangular compensation film 6 coincides with the x-axis direction of the crystal: according to the force-frequency characteristics of the crystal, when a pressure is applied to the center electrode 2 in the x-axis direction, the frequency of the crystal is raised, deviating upward from the nominal frequency. When a pulling force is applied to the x-axis direction of the central electrode 2, the frequency of the crystal is pulled down, and the nominal frequency is shifted downwards; when the acting force is larger, the caused frequency offset is larger, and the force magnitude and the frequency offset are in a direct proportion relation; therefore, when the temperature rises and is higher than the room temperature, since the thermal expansion coefficient of the compensation film is larger than that of the central electrode 2, the expansion amplitude of the compensation film is larger than that of the central electrode at this time, and similarly, when the temperature is lower than the room temperature, the contraction amplitude of the compensation film 6 is larger than that of the central electrode 2.

The central electrode 2 and the compensation film 6 are made of two different materials, and the thermal expansion coefficient of the compensation film 6 is larger than that of the central electrode 2. So that there is a large difference in the thermal expansion coefficients of the center electrode 2 and the compensation film 6. So that the expansion situation as described in figure 2 only occurs when the ambient temperature changes. The material of the compensation film 6 is silver, the material of the central electrode 2 is gold, the chemical property of the gold material central electrode 2 is more stable than that of silver, and the gold is used as the central electrode, so that the standard frequency of the crystal is more stable, and the influence of oxidation on the crystal frequency is prevented.

The compensation film 6 is rectangular, and the compensation film 6 is perpendicular to the central line of the extension layer 3, so that the compensation film has more contact area with the central electrode 2 in the x-axis direction, and the resultant force generated by the compensation film 6 to the central electrode 2 in the x-axis direction is larger. Similarly, the shorter length of the two ends of the compensation film 6, which is the case when the contact area in this direction is relatively small, can reduce the undesirable pulling effect of the compensation force in the other direction on the wafer frequency, which is the force applied to the center electrode 2 as shown in fig. 3.

The compensation film 6 is plated on the central area of the crystal 1. Because the thickness shear vibration of the electrode is mainly concentrated in the central region of the crystal, the closer to the edge, the smaller the vibration amplitude of the edge. Therefore, when the compensation film is plated on the central electrode area, the acting force on the central electrode is more direct and concentrated. The acting force can be better transmitted to the central electrode area, so that the stress condition of the central electrode is more obvious. This force can be better used to compensate for the temperature frequency characteristics of the crystal.

When the working environment temperature of the crystal changes, the central electrode and the compensation film simultaneously expand with heat and contract with cold. Since the central electrode 2 and the compensation film 3 are adhered to each other, the different deformation of the two will generate a force in the contact area, so that the expansion effect of the central electrode 2 will change from the situation before the force is applied as shown in fig. 4 to the situation after the force is applied as shown in fig. 4. Therefore, to achieve the same degree of deformation of the center electrode 2, it is equivalent to the effect of applying a tensile force to the center electrode 2 in the x-axis direction, as shown in fig. 5.

According to the crystal frequency characteristics, when the external acting force acts along the x-axis direction and is pressure action for the central electrode 2, the frequency of the crystal oscillator is increased; whereas when the force is in the x-axis direction and a pulling force acts for the center electrode 2, the frequency of the crystal oscillator is pulled down. And the magnitude of the pulling of the frequency is proportional to the magnitude of the force. Therefore, the crystal oscillator is subjected to an equivalent external pulling force applied to the crystal oscillator by a strip-shaped compensation film under the condition of higher than room temperature, and the frequency is pulled down. And below room temperature, equivalent to the effect of the external pressure applied to it by the strip-shaped membrane. The equivalent force acts to make the temperature-frequency characteristic of the AT-cut crystal more gentle. The compensation effect is shown in fig. 6.

The invention has good compatible effect for the existing crystal resonator production process. The stress compensation effect of the strip-shaped compensation film can be manufactured only by carrying out slight adjustment in the existing production process. And need not to take off the mask plate of original central electrode when carrying out the coating by vaporization flow of bar membrane, directly install bar membrane mask plate additional on original mask plate, can begin the coating by vaporization flow chart of compensation membrane. The production process flow chart is shown in FIG. 7.

The components and structures of the present embodiments that are not described in detail are well known in the art and do not constitute essential structural elements or elements.