Quartz crystal resonator and method for manufacturing the same

Abstract

The application belongs to the technical field of crystal element, and provides a quartz crystal resonator and a preparation method thereof.The quartz crystal resonator comprises a base, a spring, a quartz wafer and an adhesive agent, the base is provided with a plurality of springs, the quartz wafer is arranged between the plurality of springs, and the quartz wafer is bonded with the plurality of springs through the adhesive agent, and the adhesive agent is nano silver glue.The quartz wafer is bonded with the plurality of springs through the nano silver glue, so that the aging rate of the quartz crystal resonator is reduced, the production qualified rate of the quartz crystal resonator is improved, and the production cycle is greatly shortened without pre-aging for one month.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of crystal elements, and particularly relates to a quartz crystal resonator and a preparation method thereof. BACKGROUND

[0002] High-end application occasions such as communication base stations and power systems have increasingly strict requirements on the aging rate of constant temperature crystal oscillators. The aging rate index of constant temperature crystal oscillators is determined by quartz crystal resonators. In the production of existing quartz crystal resonators, conductive organic polymers are usually used as adhesives between wafers and supports. The conductive organic polymer is formed by cross-linking of small organic molecules to form a polymer network, and conductive particles are embedded in the network to form a conductive path. The main thermodynamic properties of the conductive organic polymer are determined by the organic polymer, but the creep and viscosity of the organic polymer will cause the quartz crystal resonator to be affected by the stress continuously released by the conductive organic polymer during operation, thereby further causing poor aging of the crystal oscillator. The slow decomposition of the un-solidified components in the conductive organic polymer at high temperatures is another key factor affecting the aging of the constant temperature crystal oscillator. In order to reduce the aging rate of the quartz crystal resonator, a long pre-aging treatment is required in the production process of the quartz crystal resonator to fully release the stress in the conductive organic polymer, resulting in a long production cycle. SUMMARY

[0003] Therefore, the embodiments of the present application provide a quartz crystal resonator and a preparation method thereof, aiming at solving the problems of poor aging characteristics and long production cycle of the quartz crystal resonator in the prior art.

[0004] To achieve the above-mentioned purpose, a first aspect of the embodiments of the present application provides a quartz crystal resonator, comprising:

[0005] a base, a spring piece, a quartz wafer and an adhesive, a plurality of spring pieces are arranged on the base, the quartz wafer is arranged between the plurality of spring pieces, and the quartz wafer and the plurality of spring pieces are bonded by the adhesive, characterized in that the adhesive is nano-silver glue.

[0006] As another embodiment of the present application, the content of pure silver in the nano-silver particles contained in the nano-silver glue is greater than or equal to 99%.

[0007] As another embodiment of the present application, further comprising: an electrode;

[0008] electrodes are arranged in the center area and the edge preset area of the front surface of the quartz wafer, and the electrodes arranged in the center area and the electrodes arranged in any area of the edge preset area are in communication;

[0009] The edge preset area is a region corresponding to the bonding position of the spring piece and the quartz wafer.

[0010] As another embodiment of the present application, the edge preset area is a fan-shaped area, and the nano-silver glue covers the fan-shaped area.

[0011] As another embodiment of the present application, an adhesion metal layer is arranged between the quartz wafer and the electrode.

[0012] As another embodiment of the present application, the metal of the adhesion metal layer is chromium, and the thickness of the adhesion metal layer ranges from 1 nm to 3 nm.

[0013] The metal of the electrode is gold, and the thickness of the electrode is greater than 100 nm.

[0014] The second aspect of the embodiment of the present application provides a preparation method of a quartz crystal resonator, comprising:

[0015] After the first preset film plating clamp is arranged on the front surface of the quartz wafer and the second preset film plating clamp is arranged on the back surface of the quartz wafer, an electrode layer is evaporated.

[0016] The first preset film plating clamp and the second preset film plating clamp are removed, and a quartz wafer sample is obtained.

[0017] Nano-silver glue is coated on a plurality of reeds arranged on a base.

[0018] The quartz wafer sample is arranged in the plurality of reeds and buckled, and the nano-silver glue is coated again between the quartz wafer and each reed, and a first quartz crystal resonator sample is obtained.

[0019] The first quartz crystal resonator sample is subjected to sintering and recrystallization treatment, and the second quartz crystal resonator sample after recrystallization treatment is packaged, and a quartz crystal resonator is obtained.

[0020] As another embodiment of the present application, before the electrode layer is evaporated after the first preset film plating clamp is arranged on the front surface of the quartz wafer and the second preset film plating clamp is arranged on the back surface of the quartz wafer, the method further comprises:

[0021] An adhesion metal layer is evaporated on the front and back surfaces of the quartz wafer.

[0022] The first preset film plating clamp is arranged on the front surface of the quartz wafer, and the second preset film plating clamp is arranged on the back surface of the quartz wafer, and then the electrode layer is evaporated.

[0023] The first preset film plating clamp is arranged on the front surface of the quartz wafer, and the second preset film plating clamp is arranged on the back surface of the quartz wafer, and then the electrode layer is evaporated.

[0024] As another embodiment of the present application, the first preset coating fixture is provided with a hollow region in the center region and the edge preset region of the fixture film, and the center region and any edge preset region are communicated, and the fixture film is the same as the shape and size of the quartz wafer.

[0025] The edge preset region is the region corresponding to the bonding position of the reed and the quartz wafer, and the edge preset region is a fan-shaped region.

[0026] As another embodiment of the present application, the first quartz crystal resonator sample is subjected to sintering and recrystallization treatment, and the second quartz crystal resonator sample after recrystallization treatment is packaged to obtain a quartz crystal resonator, comprising:

[0027] The annealing furnace is filled with nitrogen, the first quartz crystal resonator sample is heated in the annealing furnace, the temperature in the annealing furnace reaches a first preset temperature in a first preset time, and the first preset temperature is maintained for a second preset time;

[0028] When the second preset time is reached, the annealing furnace is pumped to a high vacuum state, the annealing furnace is heated, and the temperature in the annealing furnace reaches a second preset temperature in a third preset time;

[0029] When the temperature in the annealing furnace reaches the second preset temperature, the second preset temperature is maintained for a fourth preset time;

[0030] When the fourth preset time is reached, the annealing furnace is cooled, the temperature in the annealing furnace reaches room temperature in a fifth preset time, and a second quartz crystal resonator sample is obtained;

[0031] The second quartz crystal resonator sample is subjected to vacuum cold pressure welding packaging to obtain a quartz crystal resonator.

[0032] Compared with the prior art, the beneficial effects of the embodiments of the present application are: compared with the prior art, after the nano-silver glue is used to replace the conductive organic polymer with a high molecular base, the aging rate of the quartz crystal resonator is reduced, and the production cycle is greatly shortened without the need for a long pre-aging of up to one month. The metal chromium is arranged on the quartz wafer to improve the adhesion strength between the gold electrode and the quartz wafer. By enlarging the gold plating area of the edge of the quartz wafer and increasing the gold plating thickness, the adhesion strength between the gold electrode and the nano-silver glue is improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0034] Figure 1 is a schematic diagram of a quartz crystal resonator provided by an embodiment of the present application;

[0035] Figure 2 is a schematic diagram of a preparation method of a quartz crystal resonator provided by an embodiment of the present application;

[0036] FIG. 3(1) is a schematic diagram of a first preset coating fixture provided by an embodiment of the present application;

[0037] FIG. 3(2) is a schematic diagram of a second preset coating fixture provided by an embodiment of the present application;

[0038] Figure 4 is a schematic diagram of a quartz crystal resonator obtained by sintering and recrystallizing a first quartz crystal resonator sample and packaging a second quartz crystal resonator sample after recrystallization processing, provided by an embodiment of the present application;

[0039] Figure 5 is a temperature curve schematic diagram of nano-silver glue sintering and recrystallization provided by an embodiment of the present application. DETAILED DESCRIPTION

[0040] In the following description, specific details are set forth in order to provide a thorough understanding of embodiments of the present application. However, persons having ordinary skill in the art will appreciate that embodiments of the present application can be practiced without these specific details. In other instances, well-known systems, structures, circuits, and processes have not been described in detail in order to avoid obscuring the present application.

[0041] In order to illustrate the technical solutions of the present application, the following will be described by specific embodiments.

[0042] Figure 1 The quartz crystal resonator provided by an embodiment of the present application is described in detail as follows.

[0043] The quartz crystal resonator comprises a base 1, a spring piece 2, a quartz wafer 3, and an adhesive 4, a plurality of spring pieces 2 are arranged on the base 1, the quartz wafer 3 is arranged between the plurality of spring pieces 2, and the quartz wafer 3 is bonded to the plurality of spring pieces 2 through the adhesive 4, characterized in that the adhesive 4 is nano-silver glue.

[0044] Optionally, in the sintering process of the nano-silver particles in the nano-silver glue, the nano-silver particles gradually aggregate to form continuous silver under high-temperature driving, the content of pure silver in the nano-silver particles is greater than or equal to 99%, the mechanical properties of the silver are closer to the metal state, the silver can withstand a temperature greater than 500℃, the stress relaxation phenomenon caused by creep and viscosity is greatly reduced, and the aging characteristics of the quartz crystal resonator can be effectively improved.

[0045] As shown in Figure 1 The quartz crystal resonator further comprises an electrode 5.

[0046] The electrode 5 is arranged on the center area and the edge preset area of the front surface of the quartz wafer 3, and the electrode arranged on the center area is in communication with the electrode arranged on any area of the edge preset area.

[0047] The edge preset area corresponds to the bonding position of the reed and the quartz wafer.

[0048] As shown in Figure 1 The quartz crystal resonator comprises four reeds, the electrode on the center area is circular, the electrode on the edge preset area is fan-shaped, and one fan-shaped electrode is in communication with the center electrode. The nano-silver glue covers the fan-shaped area. The fan-shaped electrode can expand the gold plating area of the edge of the quartz wafer, increase the contact area of the nano-silver glue and the quartz wafer, and thus improve the bonding strength between the gold electrode and the nano-silver glue.

[0049] It should be noted that the back surface of the quartz wafer 3 also needs to be provided with an electrode, and the difference between the shape of the electrode on the back surface and the shape of the electrode on the front surface is that there is no edge fan-shaped electrode.

[0050] It should be noted that the fan-shaped area can be a standard fan shape or a Figure 1 partial fan shape as shown in the embodiment, and the specific shape of the fan-shaped area is not limited in the embodiment.

[0051] Optionally, an adhesion metal layer is arranged between the quartz wafer 3 and the electrode 5. The metal used in the adhesion metal layer is chromium, and the thickness of the adhesion metal layer ranges from 1 nanometer to 3 nanometers.

[0052] Optionally, the metal used in the electrode is gold, and the thickness of the electrode is greater than 100 nanometers. The increase in the thickness of the electrode can improve the bonding strength between the gold electrode and the nano-silver glue.

[0053] Since the adhesion between the nano-silver glue and the gold electrode after sintering is slightly poor, in order to solve this problem, a layer of chromium is prepared between the gold electrode and the surface of the quartz wafer. The chromium layer as an adhesion metal layer can improve the adhesion strength between the gold electrode and the quartz wafer.

[0054] The quartz crystal resonator can reduce the aging rate of the quartz crystal resonator, improve the production qualified rate of the quartz crystal resonator, and shorten the production cycle without pre-aging for one month. The metal chromium is arranged on the quartz wafer to improve the adhesion strength between the gold electrode and the quartz wafer. The gold plating area of the edge of the quartz wafer is expanded, and the gold plating thickness is increased to improve the adhesion strength between the gold electrode and the nano silver glue.

[0055] Figure 2 The preparation method of the quartz crystal resonator provided by the embodiment is shown in the schematic diagram, and the details are as follows.

[0056] In step 201, the first preset plating fixture is arranged on the front surface of the quartz wafer, the second preset plating fixture is arranged on the back surface of the quartz wafer, and then the electrode layer is evaporated.

[0057] As shown in FIG. 3(1), the first preset plating fixture is shown, and FIG. 3(2) is the second preset plating fixture.

[0058] Optionally, as shown in FIG. 3(1), the first preset plating fixture is provided with a hollow area in the center area and the edge preset area of the fixture film, and the center area and any edge preset area are communicated, and the fixture film is a fixture film with the same shape and size as the quartz wafer.

[0059] The edge preset area is a position corresponding area of the spring piece and the quartz wafer, and the edge preset area is a fan-shaped area. In this embodiment, a fan-shaped electrode is used to expand the gold plating area of the edge of the quartz wafer, increase the contact area of the nano silver glue and the quartz wafer, and thus improve the adhesion strength between the gold electrode and the nano silver glue.

[0060] Optionally, as shown in FIG. 3(2), the second preset plating fixture is provided with a hollow area in the center area of the fixture film, and a second preset edge area of the second preset plating fixture is communicated at the edge of the center area to form a hollow spoon shape.

[0061] Optionally, the electrode layer is evaporated on the surface of the quartz wafer. The electrode evaporated on the hollow area of the first preset plating fixture and the second preset plating fixture is directly on the surface of the quartz wafer.

[0062] Optionally, the metal of the electrode layer can be gold, and the thickness of the electrode layer can be greater than 100 nanometers. Increasing the thickness of the electrode layer can further improve the adhesion strength between the gold electrode and the nano silver glue.

[0063] Optionally, before this step, it also includes:

[0064] The front and back surfaces of the quartz wafer are respectively evaporated with an adhesion metal layer.

[0065] Since the adhesion between the nano-silver paste and the gold electrode is slightly poor after sintering, a layer of chromium is first deposited before the electrode is deposited onto the surface of the quartz wafer to solve this problem. The chromium layer acts as an adhesion layer to improve the adhesion strength between the gold electrode and the wafer.

[0066] Optionally, the surface of the quartz wafer is first cleaned, and then an adhesion metal layer is deposited on both sides of the quartz wafer. The adhesion metal layer uses chromium as the metal, and its thickness ranges from 1 nanometer to 3 nanometers. For example, the thickness of the adhesion metal layer can be 2 nanometers.

[0067] Then, the first preset coating fixture is placed on the front side of the quartz wafer with the metal layer adhered, and the second preset coating fixture is placed on the back side of the quartz wafer with the metal layer adhered, and the electrode layer is deposited by vapor deposition.

[0068] Step 202: Remove the first preset coating fixture and the second preset coating fixture to obtain a quartz wafer sample.

[0069] Optionally, after removing the first preset coating fixture and the second preset coating fixture, electrodes can be formed on the surface of the quartz wafer.

[0070] Step 203: Coat the multiple reeds set on the base with nano silver paste.

[0071] In this embodiment, in order to improve the bonding strength, an appropriate amount of nano silver glue can be applied to the spring first, and then the quartz crystal sample can be fastened with the spring, and then nano silver glue can be applied again at the contact position between the quartz crystal sample and the spring.

[0072] Step 204: Place the quartz wafer sample in the plurality of springs and fasten it, and then coat the nano silver paste between the quartz wafer and each spring to obtain the first quartz crystal resonator sample.

[0073] Optionally, in this step, the nano-silver paste can be applied to cover the electrode sector area, i.e. the sector electrode on the surface of the quartz wafer, to improve the adhesion strength.

[0074] Step 205: The first quartz crystal resonator sample is sintered and recrystallized, and the recrystallized second quartz crystal resonator sample is packaged to obtain a quartz crystal resonator.

[0075] like Figure 4 As shown, the sintering and recrystallization process in this step may include the following steps:

[0076] Step 401, fill the annealing furnace with nitrogen, place the first quartz crystal resonator sample in the annealing furnace for heating, and make the temperature in the annealing furnace reach a first preset temperature in a first preset time, and keep the first preset temperature for a second preset time.

[0077] Optionally, the nano-silver colloid in the annealing furnace is prevented from being oxidized, and nitrogen is filled in the annealing furnace when the first quartz crystal resonator sample is heated.

[0078] Optionally, as shown in the temperature curve schematic diagram of nano-silver colloid sintering and recrystallization, the first preset time can be 1 hour, the first preset temperature can be 275°C, and the second preset time can be 2 hours. That is, the first quartz crystal resonator sample is heated to 275°C in 1 hour, and the temperature of 275°C is kept for 2 hours, at which time the nano-silver colloid is sintered. Figure 5

[0079] Step 402, when the second preset time is reached, the annealing furnace is pumped to a high vacuum state, the annealing furnace is heated, and the temperature in the annealing furnace reaches a second preset temperature in a third preset time.

[0080] Optionally, the third preset time can be 1 hour, and the second preset temperature can be 400°C. That is, before recrystallization, the temperature of the annealing furnace is raised to 400°C.

[0081] Step 403, when the temperature in the annealing furnace reaches the second preset temperature, keep the second preset temperature for a fourth preset time.

[0082] Optionally, the fourth preset time can be 4 hours, at which time the nano-silver colloid is recrystallized, further condensed into a block, and mutual diffusion occurs between the silver atoms of the nano-silver colloid and the gold atoms of the gold electrode, and the adhesion is further enhanced.

[0083] Step 404, when the fourth preset time is reached, cool the annealing furnace, make the temperature in the annealing furnace reach room temperature in a fifth preset time, and obtain a second quartz crystal resonator sample;

[0084] Optionally, the fifth preset time can be 3 hours.

[0085] Step 405, vacuum cold-press welding packaging is performed on the second quartz crystal resonator sample to obtain a quartz crystal resonator.

[0086] The nano-silver colloid is sintered by the above special sintering, and needs to be subjected to high-temperature recrystallization treatment after sintering. The recrystallization temperature needs to be higher than the recrystallization temperature of gold and silver, so that gold and silver diffuse with each other, and the adhesion between the gold electrode and the nano-silver colloid is further enhanced. ​

[0087] The preparation method of the quartz crystal resonator reduces the aging rate of the quartz crystal resonator by using nano-silver glue instead of the conductive organic polymer with a polymer as a matrix, and the production cycle is greatly shortened without pre-aging for a month. The metal chromium is arranged on the quartz wafer to improve the adhesion strength between the gold electrode and the quartz wafer. The adhesion strength between the gold electrode and the nano-silver glue is improved by enlarging the gold plating area of the edge of the quartz wafer and increasing the gold plating thickness.

[0088] It should be understood that the size of the serial number of each step in the above-mentioned embodiments does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0089] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A quartz crystal resonator comprising: The base, the reed, the quartz wafer and the adhesive, the base is provided with a plurality of reeds, the quartz wafer is arranged between the plurality of reeds, and the quartz wafer is bonded with the plurality of reeds by the adhesive, characterized in that the adhesive is nano silver glue; The content of pure silver in the nano silver particles contained in the nano silver glue is greater than or equal to 99%; The center area and the edge preset area of the front surface of the quartz wafer are respectively provided with electrodes, wherein the electrodes provided in the center area are in communication with the electrodes provided in any area of the edge preset area; the metal used for the electrodes is gold, and the thickness of the electrodes is greater than 100 nanometers; The edge preset area is the position corresponding area of the bonding position of the reed and the quartz wafer; The edge preset area is a fan-shaped area, and the electrodes in the edge preset area are fan-shaped, and the nano silver glue covers the fan-shaped area; The quartz crystal resonator is prepared based on the preparation method of the quartz crystal resonator, and the preparation method of the quartz crystal resonator comprises: After placing the first preset plating fixture on the front surface of the quartz wafer and placing the second preset plating fixture on the back surface of the quartz wafer, an electrode layer is evaporated; The first preset plating fixture and the second preset plating fixture are removed to obtain a quartz wafer sample; Nano silver glue is coated on the plurality of reeds arranged on the base; The quartz wafer sample is placed in the plurality of reeds and buckled, and the nano silver glue is coated again between the quartz wafer and each reed to obtain a first quartz crystal resonator sample; The first quartz crystal resonator sample is subjected to sintering and recrystallization treatment, and the second quartz crystal resonator sample after recrystallization treatment is packaged to obtain a quartz crystal resonator; The recrystallization temperature of the recrystallization treatment is higher than the recrystallization temperature of gold and silver.

2. The quartz crystal resonator of claim 1, wherein, An adhesive metal layer is arranged between the quartz wafer and the electrodes.

3. The quartz crystal resonator of claim 2, wherein: The metal used for the adhesive metal layer is chromium, and the thickness of the adhesive metal layer ranges from 1 nanometer to 3 nanometers.

4. A method of manufacturing a quartz crystal resonator, characterized by, Comprising: After placing the first preset plating fixture on the front surface of the quartz wafer and placing the second preset plating fixture on the back surface of the quartz wafer, an electrode layer is evaporated; wherein the center area and the edge preset area of the front surface of the quartz wafer are respectively provided with electrodes, wherein the electrodes provided in the center area are in communication with the electrodes provided in any area of the edge preset area; the metal used for the electrodes is gold, and the thickness of the electrodes is greater than 100 nanometers; the edge preset area is the position corresponding area of the bonding position of the reed and the quartz wafer; the edge preset area is a fan-shaped area, and the electrodes in the edge preset area are fan-shaped; The first preset plating fixture and the second preset plating fixture are removed to obtain a quartz wafer sample; Nano silver glue is coated on the plurality of reeds arranged on the base; Place the quartz wafer sample in the plurality of reeds and tighten, and re-coat the nano-silver glue between the quartz wafer and each reed, to obtain a first quartz crystal resonator sample; the nano-silver particles contained in the nano-silver glue have a pure silver content greater than or equal to 99%; the nano-silver glue covers the fan-shaped area; Sinter and recrystallize the first quartz crystal resonator sample, and package the second quartz crystal resonator sample after recrystallization to obtain a quartz crystal resonator; The recrystallization temperature of the recrystallization treatment is higher than the recrystallization temperature of gold and silver.

5. The method of producing a quartz crystal resonator according to claim 4, wherein After placing the first pre-coated jig on the front surface of the quartz wafer and the second pre-coated jig on the back surface of the quartz wafer, before evaporating the electrode layer, it further comprises: Evaporate an adhesion metal layer on the front and back surfaces of the quartz wafer; After placing the first pre-coated jig on the front surface of the quartz wafer and the second pre-coated jig on the back surface of the quartz wafer, evaporate the electrode layer, which comprises: Place the first pre-coated jig on the front surface of the quartz wafer with the adhesion metal layer, and place the second pre-coated jig on the back surface of the quartz wafer with the adhesion metal layer, then evaporate the electrode layer.

6. The method for producing a quartz crystal resonator according to claim 4 or 5, wherein The first pre-coated jig is provided with a hollow area in the center area and the edge pre-set area of the jig film, and the jig film is a jig film with the same shape and size as the quartz wafer.

7. The method for producing a quartz crystal resonator according to claim 4 or 5, wherein The first quartz crystal resonator sample is sintered and recrystallized, and the second quartz crystal resonator sample after recrystallization is packaged to obtain a quartz crystal resonator, which comprises: Fill the annealing furnace with nitrogen, place the first quartz crystal resonator sample in the annealing furnace, heat the annealing furnace to a first preset temperature in a first preset time, and maintain the first preset temperature for a second preset time; When the second preset time is reached, the annealing furnace is pumped to a high vacuum state, and the annealing furnace is heated to a second preset temperature in a third preset time; When the temperature in the annealing furnace reaches the second preset temperature, maintain the second preset temperature for a fourth preset time; When the fourth preset time is reached, cool the annealing furnace to room temperature in a fifth preset time to obtain a second quartz crystal resonator sample; Vacuum cold pressure welding packaging is performed on the second quartz crystal resonator sample to obtain a quartz crystal resonator. Vacuum cold pressure welding packaging is performed on the second quartz crystal resonator sample to obtain a quartz crystal resonator.

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