Manufacturing method of quartz tuning fork resonator

Abstract

The invention discloses a manufacturing method of a quartz tuning fork resonator, which can be used for etching a quartz tuning fork resonator shape and a resistance groove on one surface in one step on the basis of a size effect, so that the processing steps of a quartz resonance device with a layered structure are simplified, and the production efficiency is improved by 45%. And meanwhile, the problems of low production yield, poor device size consistency and the like caused by an overlong processing flow are avoided, and the produced tuning fork device has the advantages of symmetrical appearance and stable vibration frequency.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a quartz tuning fork resonator, belonging to the technical field of resonator manufacturing. Background Art

[0002] Quartz crystals are widely used in piezoelectric resonant devices, such as AFM probes, resonators, accelerometers, gyroscopes, etc., because of their excellent physical and chemical properties such as high high-voltage electricity conversion efficiency, high insulation, and low expansion coefficient. The existing traditional quartz processing technology uses a double-sided multi-step overlay process. Since the surface of the quartz tuning fork resonator has a three-dimensional layered structure, it is necessary to go through double-sided cleaning, coating, spin / spray glue, photolithography, development, graphics, quartz etching and other tedious process steps to process and manufacture the tuning fork shape and surface layered structure separately, which makes the production process complicated and the production efficiency low. Summary of the invention

[0003] The invention provides a method for manufacturing a quartz tuning fork resonator, which solves the problem disclosed in the background technology.

[0004] According to one aspect of the present disclosure, there is provided a method for manufacturing a quartz tuning fork resonator, comprising: The quartz crystal piece is sequentially cleaned, dried / blown dry, and coated with a metal film to obtain a once-processed quartz crystal piece; The two surfaces of the once-processed quartz crystal sheet are sequentially subjected to spin coating of photoresist, one-step photolithography, development and post-baking to obtain a second-processed quartz crystal sheet; wherein the one-step photolithography is to etch out the quartz tuning fork resonator shape and the resistor groove on one side in one step based on the size effect; Stripping the photoresist on the second-processed quartz crystal piece, and removing the metal film in the non-quartz tuning fork resonator area, to obtain a third-processed quartz crystal piece; The quartz crystal piece processed three times is chemically etched to obtain a quartz tuning fork resonator.

[0005] In some embodiments of the present disclosure, the process of cleaning the quartz crystal piece includes: Immerse the quartz crystal piece in a container containing the mixed treatment liquid, put it into an ultrasonic tank for ultrasonic treatment, and rinse the quartz crystal piece after ultrasonic treatment with pure water and isopropyl alcohol in turn.

[0006] In some embodiments of the present disclosure, the process of coating a metal film on a dried / blown quartz crystal sheet includes: The dried / blown quartz crystal piece is fixed on a mask fixture, and a metal film is plated on the quartz crystal piece using a vacuum thermal evaporation method or a magnetron sputtering method.

[0007] In some embodiments of the present disclosure, when one-step photolithography is performed on one side of a quartz crystal sheet and another side is photolithographically performed, a preset mark is first used for alignment, and then etching is performed.

[0008] In some embodiments of the present disclosure, a one-step photolithography process includes: Determine the required etching depth for each part of the quartz tuning fork resonator shape and resistor slot; Based on the size effect, the etching line width corresponding to the etching depth is determined, and according to the etching line width corresponding to each part of the quartz tuning fork resonator shape and the resistor groove, the quartz tuning fork resonator shape and the resistor groove are etched out in one step.

[0009] In some embodiments of the present disclosure, the process of stripping the photoresist on the secondary processed quartz crystal piece includes: soaking the secondary processed quartz crystal piece in acetone and isopropyl alcohol in sequence.

[0010] In some embodiments of the present disclosure, the process of removing the metal film in the non-quartz tuning fork resonator region includes: immersing the metal film in etching solutions of corresponding materials in sequence from the outside to the inside.

[0011] In some embodiments of the present disclosure, the process of chemically etching the quartz crystal piece processed three times includes: The quartz crystal piece treated three times is placed in an etching tank filled with etching liquid, and the etching liquid is stirred during etching.

[0012] The beneficial effects achieved by the present invention are as follows: Based on the size effect, the present invention can etch the shape of a quartz tuning fork resonator and a resistor groove on one side in one step, simplifying the processing steps of quartz resonance devices with a layered structure, and improving the production efficiency by 45%. At the same time, it avoids the problems of low production yield and poor device size consistency caused by a long processing flow, and the tuning fork device after production has the advantages of symmetrical shape and stable vibration frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of the structure of a quartz tuning fork resonator; Figure 2 A flow chart of a method for manufacturing a quartz tuning fork resonator. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. It is obvious that the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0015] Unless otherwise specified, the relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure.

[0016] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0017] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0018] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0019] It should be noted that similar symbols and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it does not require further discussion in subsequent figures.

[0020] In order to solve the problems existing in the existing processing technology of quartz resonant devices with layered structures, the present disclosure provides a method for manufacturing a quartz tuning fork resonator, specifically, etching the shape of the quartz tuning fork resonator and the resistor groove in one step.

[0021] Figure 1 The structure of an existing quartz tuning fork resonator mainly includes a base and a pair of tuning fork arms connected to the base. Grooves along the length direction are provided on the front and back sides of the tuning fork arms. Figure 1 As can be seen from the method part, the bottom of the groove is sawtooth-shaped. Figure 1 The quartz tuning fork resonator is a quartz resonance device with a layered structure.

[0022] Figure 2 This is a schematic diagram of an embodiment of a method for manufacturing a quartz tuning fork resonator disclosed in the present invention, which is an improvement on the existing process, specifically an improvement on the photolithography process.

[0023] like Figure 2As shown, in step 1 of the embodiment, the quartz crystal piece is cleaned, dried / blown dry, and coated with a metal film in sequence to obtain a once-processed quartz crystal piece.

[0024] In some embodiments, the quartz crystal piece can be immersed in a container containing a mixed treatment liquid, and then placed in an ultrasonic tank for ultrasound treatment. The quartz crystal piece after ultrasound treatment is rinsed with pure water and isopropyl alcohol in turn. Through the above cleaning, impurities on the quartz crystal piece can be effectively removed and the new energy of the quartz tuning fork resonator can be improved.

[0025] It should be noted that a mixture of alkaline cleaning solution and pure water can be used as a mixed treatment liquid, wherein the volume ratio of alkaline cleaning solution to pure water can be 2:5. In order to ensure the cleaning effect, a beaker can be used as a container to immerse the quartz crystal piece in the mixed treatment liquid. If there are multiple quartz crystal pieces, they can be evenly distributed at intervals of 1 cm. After the beaker is placed in the ultrasonic tank, it will be heated in a water bath at 50~60℃, and then ultrasonically cleaned for 10 minutes. After the ultrasonic cleaning is completed, the quartz crystal piece in the beaker is rinsed with pure water for 1 minute, then rinsed with isopropyl alcohol for 2 minutes, and dried in an oven or blown dry with nitrogen.

[0026] In some embodiments, the quartz crystal piece after drying / blowing can be fixed on a mask fixture, and a metal film can be plated on the quartz crystal piece by a vacuum thermal evaporation method or a magnetron sputtering method.

[0027] It should be noted that generally metal film is plated in two layers, the first layer is chromium film, and the second layer is gold film. The chromium film is used as an adhesion layer with a thickness of 5~50nm, and the thickness of the gold film is greater than 50nm.

[0028] return Figure 2 In step 2 of the embodiment, both sides of the once-treated quartz crystal sheet are sequentially subjected to spin coating of photoresist, one-step photolithography, development and post-baking to obtain a second-treated quartz crystal sheet; wherein the one-step photolithography is to etch out the quartz tuning fork resonator shape and the resistor groove on one side in one step based on the size effect.

[0029] It should be noted that, taking the front side lithography followed by the back side lithography as an example, the specific process of step 2 can be as follows: 21) Spin-coat photoresist on the front side; 22) Perform one-step photolithography on the front side; 23) Perform front-side development and post-baking; 24) Spin-coat photoresist on the back side; 25) Perform one-step photolithography on the back side; 26) Perform back-side development and post-baking.

[0030] It should be noted that in order to ensure symmetry when etching the front and back sides, when performing one-step photolithography on the back side, a preset mark is first used for alignment, such as the common cross mark alignment, and then etching is performed.

[0031] It should be noted that in 22) and 25), the device shape and the resistor slot structure are simultaneously drawn in the mask plate, and the graphic transfer is performed simultaneously in a single step, where different structures are designed by using different line width combinations. This design uses the size effect of quartz crystal etching to achieve different etching rates, so that different etching line widths have different etching depths, and a layered structure can be produced by etching in one step. The specific process can be as follows: A1) Determine the required etching depth for the quartz tuning fork resonator shape and resistor slots; A2) Based on the size effect, the etching line width corresponding to the etching depth is determined, and according to the etching line width corresponding to each part of the quartz tuning fork resonator shape and the resistor groove, the quartz tuning fork resonator shape and the resistor groove are etched out in one step.

[0032] Based on the size effect, the quartz tuning fork resonator shape and resistor groove on one side are etched in one step, which simplifies the processing steps of quartz resonator devices with layered structures and improves production efficiency by 45%.

[0033] It should be noted that the above-mentioned development time can be controlled at 10-25 seconds, the post-baking temperature can be controlled at 150° C., and the post-baking time can be controlled at 10-15 minutes.

[0034] return Figure 2 In step 3 of the embodiment, the photoresist on the second-processed quartz crystal sheet is stripped off, and the metal film in the non-quartz tuning fork resonator area is removed to obtain a third-processed quartz crystal sheet.

[0035] It should be noted that the process of stripping the photoresist can be to soak the secondary treated quartz crystal piece in acetone and isopropanol in sequence. Specifically, when stripping the photoresist, the quartz crystal piece is first soaked in acetone for 10 minutes, and then soaked in isopropanol for 5 minutes.

[0036] It should be noted that the process of removing the metal film can be based on the material of the metal film from the outside to the inside, and the metal film can be immersed in the corresponding material etching solution in sequence. Specifically, taking chromium inside and gold outside as an example, the quartz crystal piece is first immersed in the gold etching solution for 2 minutes, and then immersed in the chromium etching solution for 20 seconds; wherein, the gold etching solution can be a mixture of potassium iodide, iodine and deionized water, and the mass ratio can be 2:1:2, and the chromium etching solution can be a cerium ammonium nitrate solution.

[0037] return Figure 2 , step 4 of the embodiment, chemically corrodes the quartz crystal sheet processed three times to obtain a quartz tuning fork resonator.

[0038] It should be noted that the chemical etching process can be to place the quartz crystal piece treated three times into a corrosion tank filled with corrosion liquid, and stir the corrosion liquid during etching; wherein, the corrosion liquid can be composed of 49% hydrofluoric acid and 40% ammonium fluoride in a volume ratio of 4:3, and the temperature of the corrosion solution can be controlled at 70°C; during etching, a magnetic stirrer is added to the corrosion tank for stirring.

[0039] The above method simplifies the processing steps of quartz resonant devices with a layered structure, improves production efficiency, and can avoid problems such as low production yield and poor device size consistency caused by a long processing flow. In addition, the tuning fork device after production has the advantages of symmetrical appearance and stable vibration frequency.

[0040] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for manufacturing a quartz tuning fork resonator, characterized in that: include: The quartz crystal piece is sequentially cleaned, dried / blown dry, and coated with a metal film to obtain a once-processed quartz crystal piece; The two surfaces of the once-processed quartz crystal sheet are sequentially subjected to spin coating of photoresist, one-step photolithography, development and post-baking to obtain a second-processed quartz crystal sheet; wherein the one-step photolithography is to etch out the quartz tuning fork resonator shape and the resistor groove on one side in one step based on the size effect; Stripping the photoresist on the second-processed quartz crystal piece, and removing the metal film in the non-quartz tuning fork resonator area, to obtain a third-processed quartz crystal piece; The quartz crystal piece processed three times is chemically etched to obtain a quartz tuning fork resonator.

2. The method for manufacturing a quartz tuning fork resonator according to claim 1, characterized in that: The process of cleaning a quartz crystal includes: Immerse the quartz crystal piece in a container containing the mixed treatment liquid, put it into an ultrasonic tank for ultrasonic treatment, and rinse the quartz crystal piece after ultrasonic treatment with pure water and isopropyl alcohol in turn.

3. The method for manufacturing a quartz tuning fork resonator according to claim 1, characterized in that: The process of coating the metal film on the dried / blown quartz crystal includes: The dried / blown quartz crystal piece is fixed on a mask fixture, and a metal film is plated on the quartz crystal piece using a vacuum thermal evaporation method or a magnetron sputtering method.

4. The method for manufacturing a quartz tuning fork resonator according to claim 1, characterized in that: When one-step photolithography of one side of a quartz crystal sheet is completed and then another side is photolithographically processed, a preset mark is first used for alignment, and then etching is performed.

5. The method for manufacturing a quartz tuning fork resonator according to claim 1 to 4, characterized in that: The one-step lithography process includes: Determine the required etching depth for each part of the quartz tuning fork resonator shape and resistor slot; Based on the size effect, the etching line width corresponding to the etching depth is determined, and according to the etching line width corresponding to each part of the quartz tuning fork resonator shape and the resistor groove, the quartz tuning fork resonator shape and the resistor groove are etched out in one step.

6. The method for manufacturing a quartz tuning fork resonator according to claim 1, characterized in that: The process of stripping the photoresist on the secondary treated quartz crystal piece includes: soaking the secondary treated quartz crystal piece in acetone and isopropyl alcohol in sequence.

7. The method for manufacturing a quartz tuning fork resonator according to claim 1, characterized in that: The process of removing the metal film in the non-quartz tuning fork resonator area includes: immersing the metal film in etching solutions of corresponding materials in sequence according to the materials of the metal film from outside to inside.

8. The method for manufacturing a quartz tuning fork resonator according to claim 1, characterized in that: The process of chemically etching a triple-treated quartz crystal includes: The quartz crystal piece treated three times is placed in an etching tank filled with etching liquid, and the etching liquid is stirred during etching.

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