Method for the frequency-free production of a crystal resonator

Abstract

The application discloses a frequency tuning-free preparation method of a crystal resonator, and belongs to the field of electronic components, which comprises the following steps: S0, after a wafer is installed in a crystal resonator sputtering coating device and placed in a magnetron sputtering machine; S1, coating, the target thickness of a film layer is 100nm-200nm, and the film layer is composed of a transition layer and a gold layer, wherein the target thickness of the transition layer is 5nm-15nm; S3, dividing the wafer to form a bare crystal resonator chip; S4, assembling, dispensing and patching; S5, solidification, which is carried out in a solidification furnace; S6, wire bonding and sealing welding; S7, final electrical performance test; S8, laser marking; S9, initial banding; S10, checking the marking; S11, continuing the banding; and S12, packaging. The application solves the electrode diffusion problem of a high-frequency crystal resonator due to the too small thickness of the wafer in the existing crystal resonator sputtering coating device.

Description

Technical Field

[0001] This invention relates to the field of electronic components, and in particular to a method for fabricating a crystal resonator without frequency modulation. Background Technology

[0002] Quartz crystal resonators not only have highly stable physical and chemical properties, but also have extremely low elastic vibration loss, high frequency stability, and high Q value. Therefore, crystal resonators have become important components for stabilizing and selecting frequencies.

[0003] In the manufacturing process of quartz crystal resonators, the coating process is the core link. The coating process directly determines the frequency stability, anti-aging performance and environmental adaptability of the resonator. Among them, magnetron sputtering coating has become an important coating method for crystal resonators due to its high deposition rate, low substrate temperature rise and excellent film density and adhesion.

[0004] In existing magnetron sputtering coating processes for crystal resonators, the following methods are employed: Figures 1-3 The coating apparatus shown places or mounts wafer 1. Before placing wafer 1, the lower electrode mask 2 is stacked on the base plate (not shown in the figure, the base plate is equipped with positioning posts). Then, the positioning plate 3 with wafer positioning groove 4 is stacked on the lower electrode mask 2. The wafer 1 mounting mechanism is then used to place wafer 1 into the wafer positioning groove 4. After the wafer 1 is installed, the upper electrode mask 5 is stacked on the positioning plate 3. Finally, the magnetic cover plate (not shown in the figure) is placed on the upper electrode mask 5. Positioning holes 6 are provided on the lower electrode mask 2, the positioning plate 3, and the upper electrode mask 5. When stacked, the positioning post passes through the positioning holes 6 on the lower electrode mask 2, the positioning plate 3, and the upper electrode mask 5. Under the adsorption of the magnetic cover plate, the lower electrode mask 2, the positioning plate 3, and the upper electrode mask 5 are attached to the crystal resonator coating device with a tight fit. During coating, the crystal resonator coating device is vertically fixed in the magnetron sputtering machine. The target particles (electrode particles) sputtered from the target material pass through the electrode holes 7 on the upper electrode mask 5 or the lower electrode mask 2 from both sides of the crystal resonator coating device and are deposited on the upper and lower surfaces of the wafer 1 to form the upper electrode and the lower electrode.

[0005] To reduce the gap between the upper electrode mask 5 and the lower electrode mask 2, low- and mid-frequency products achieve this by designing the thickness of the positioning plate 3 to be the same as or close to the thickness of the wafer 1, such as... Figure 4 As shown, Figure 4 In the middle, the gap between the upper electrode mask 5 or the lower electrode mask 2 of the low-frequency product and the wafer 1 (see...) Figure 4 The area within the middle circle is very small or virtually nonexistent. However, in the production of high-frequency crystal resonators, Figure 1The current crystal resonator coating apparatus is impractical because the thickness of high-frequency wafers can be as thin as 0.017 mm (fundamental frequency 96 MHz), while the minimum processing thickness of the positioning plate 3 is currently 0.04 mm. Therefore, when the wafer thickness is <0.04 mm, a certain gap will exist between the wafer 1 and the upper electrode mask 5 or the lower electrode mask 2, causing the upper electrode and / or lower electrode formed after coating to differ from the designed upper and lower electrodes, affecting the performance of the high-frequency crystal resonator. Therefore, existing high-frequency crystal resonators require frequency modulation after coating (using laser or ion beam to process the film layer). Thus, the existing manufacturing process of high-frequency crystal resonators is as follows: the prepared wafer 1 is installed in the coating apparatus for coating, then sequentially frequency-modulated and segmented (i.e.,...). The process includes: dividing the chip into individual bare crystal chips with precision electrodes; assembly (assembling the bare crystal chip with a prepared base and cover); dispensing and placement (applying conductive silver paste to specific locations within the base cavity, then using a high-precision placement machine to pick up the divided individual chips and precisely place them onto the paste dots); curing (curing the silver paste, fixing the chip and forming an electrical connection); wire bonding and sealing; final electrical performance testing; laser marking (using a transfer robotic arm to move products that have passed the final electrical performance test parameters (i.e., resonators) to the laser marking alignment position for laser marking); initial tape feeding (using a transfer robotic arm to move the laser-marked resonators to a tape feeding machine for tape feeding); checking the marking marks; manual tape feeding; and packaging.

[0006] The above background information is provided to facilitate understanding of the present invention and is not intended to be publicly known technology disclosed to the general public prior to the application of this invention. Summary of the Invention

[0007] The present invention provides a method for fabricating a crystal resonator without frequency modulation, which aims to improve at least one of the problems mentioned in the background art.

[0008] The technical solution is: a method for fabricating a crystal resonator without frequency modulation, comprising the following steps:

[0009] S0, the wafer is installed in the crystal resonator sputtering coating apparatus and then placed in the magnetron sputtering machine;

[0010] S1, film deposition, with a target film thickness of 100nm~200nm, the film consists of a transition layer and a gold layer, wherein the target thickness of the transition layer is 5nm~15nm;

[0011] S3, divide the wafer to form a bare crystal oscillator chip;

[0012] S4, assembly, dispensing and mounting;

[0013] S5, Curing, curing is carried out in a curing oven;

[0014] S6, wire bonding and sealing;

[0015] S7, final electrical performance test;

[0016] S8, laser marking;

[0017] S9, first time lacing;

[0018] S10, Check the markings;

[0019] S11, continue weaving;

[0020] S12, Packaging

[0021] The crystal resonator sputtering coating apparatus sequentially includes a base plate, a lower electrode mask, a positioning plate, an upper electrode mask, and a magnetic cover plate. The positioning plate has a wafer positioning groove, in which the wafer is installed. Both the upper and lower electrode masks have electrode holes. The thickness of the positioning plate is denoted as h. 定 Of the two electrode masks, the upper electrode mask and the lower electrode mask, at least one of the plates has a diffusion protrusion on the side facing the wafer to prevent electrode particles from diffusing during deposition. The size of the diffusion protrusion matches the size of the wafer positioning groove. During assembly, the diffusion protrusion is located within the wafer positioning groove. The wafer thickness is denoted as h. 晶 0.017mm ≤h 晶 <h 定 .

[0022] Preferably, the curing conditions are as follows: the temperature is increased from room temperature to 150°C at a rate of 2°C / min, maintained at 150°C for 90 minutes, and then naturally cooled to room temperature, with the curing atmosphere being air.

[0023] Preferably, after S1 and before S3, S2 is included, which is heat treatment. The heat treatment conditions are: heating from room temperature to 350°C to 450°C at a rate of 5°C / min to 15°C / min, holding at that temperature for 20 minutes to 45 minutes, cooling with the furnace, and the heat treatment atmosphere is nitrogen.

[0024] Preferably, after S1 and before S3, S2 is included, which is heat treatment. The heat treatment conditions are: heating from room temperature to 200°C at a rate of 10°C / min, then heating from 200°C to 400°C at a rate of 5°C / min, holding at that temperature for 30 minutes, and then cooling in the furnace. The heat treatment atmosphere is nitrogen.

[0025] Preferably, S10 includes the following steps:

[0026] S101, the CCD takes a picture of the marking mark on the resonator. The server receives the picture information from the CCD and makes a judgment on whether the marking mark is qualified and displays it on the display device. If the judgment is qualified, proceed to S11; if the judgment is unqualified, proceed to S102.

[0027] S102, the server simultaneously issues an alarm command and sends a command to the actuator. The actuator moves the light panel inward to expose the resonator on the tape that failed the marking inspection. The server also sends a replacement command to the transfer robot arm.

[0028] S103, after receiving the replacement instruction, the transfer robot arm takes the unqualified resonator out of the tape grid and puts it into the collection box, and picks one of the marked resonators from the laser marking column position and puts it into the grid. The actuator resets the light board and enters S11.

[0029] Preferably, S10 includes the following steps:

[0030] S101, the CCD takes a picture of the marking mark on the resonator. The server receives the picture information from the CCD and makes a judgment on whether the marking mark is qualified and displays it on the display device. If the judgment is qualified, proceed to S11; if the judgment is unqualified, proceed to S102.

[0031] S102, the server simultaneously issues an alarm command and sends a command to the actuator. The actuator moves the light panel inward to expose the resonator on the tape that failed the marking inspection. The server also sends a replacement command to the transfer robot arm.

[0032] S103: After receiving the replacement command, the transfer robotic arm removes the unqualified resonator from the tape tray and places it into the collection box. It also picks up one of the marked resonators from the laser marking column and places it into the corresponding slot. The CCD takes a picture of the marking mark on the replaced resonator. The server receives the CCD's picture information and determines whether the marking mark is qualified, displaying the result on the display device. If the mark is qualified, the actuator resets the light board and proceeds to S11. If the mark is unqualified, this step is repeated until the mark is qualified. The actuator then resets the light board and proceeds to S11.

[0033] Preferably, the diffusion protrusion is an upper electrode diffusion protrusion, which is located on the upper electrode mask, and the thickness of the upper electrode diffusion protrusion is denoted as h. 上 h 上 +h 晶 = h 定 .

[0034] Preferably, the diffusion protrusion is a lower electrode diffusion protrusion, which is located on the lower electrode mask, and the thickness of the lower electrode diffusion protrusion is denoted as h. 下 h 下 +h 晶 = h 定 .

[0035] As a preferred option, h 定 =0.04mm.

[0036] Preferably, the diffusion-blocking protrusion includes an upper electrode diffusion-blocking protrusion and a lower electrode diffusion-blocking protrusion, the upper electrode diffusion-blocking protrusion being located on the upper electrode mask, and the thickness of the upper electrode diffusion-blocking protrusion being denoted as h. 上 The lower electrode dispersion protrusion is located on the lower electrode mask, and the thickness of the lower electrode dispersion protrusion is denoted as h. 下 h 上 +h 下 +h 晶 = h 定 .

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] This invention solves the electrode diffusion problem in existing crystal resonator sputtering coating equipment due to the small wafer thickness of high-frequency crystal resonators by improving the electrode mask template. When producing crystal resonators with a wafer thickness of less than 0.04 mm, qualified high-frequency crystal resonators can be produced without frequency tuning.

[0039] The present invention also improves the long-term reliability of the crystal resonator by adding a heat treatment process after coating and under specific heat treatment conditions. Under high temperature aging conditions of 125°C and 168 hours, the absolute value of frequency aging drift is less than 1 ppm and the resistance aging drift is less than 1%.

[0040] This invention also replaces the manual replacement of defective crystal resonators with intelligent replacement of defective crystal resonators, thereby improving production efficiency and reducing the risk of customer complaints. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the assembly of a crystal resonator sputtering coating device, which is part of the background technology of this invention.

[0042] Figure 2 This is an exploded view of the crystal resonator sputtering coating apparatus, which is the background technology of this invention.

[0043] Figure 3 This is a schematic cross-sectional view of the crystal resonator sputtering coating apparatus, which is the background technology of this invention.

[0044] Figure 4 This is a schematic diagram illustrating the state between the electrode mask and the wafer during the coating process of a crystal resonator sputtering coating apparatus used in low- and medium-frequency products.

[0045] Figure 5 This is a schematic diagram of the state between the electrode mask and the wafer after the high-frequency crystal resonator is assembled in the crystal resonator sputtering coating apparatus of the present invention.

[0046] Figure 6This is a schematic diagram of another state between the electrode mask and the wafer after the high-frequency crystal resonator is assembled in the crystal resonator sputtering coating apparatus of the present invention.

[0047] Figure 7 This is a schematic diagram of another state between the electrode mask and the wafer after the high-frequency crystal resonator is assembled in the crystal resonator sputtering coating apparatus of the present invention.

[0048] Figure 8 yes Figure 5 A schematic diagram after the coating is completed;

[0049] Figure 9 yes Figure 6 A schematic diagram after the coating is completed;

[0050] Figure 10 yes Figure 7 A schematic diagram after the coating is completed;

[0051] Figure 11 This is a schematic diagram of the main view of the upper electrode mask template of the present invention;

[0052] Figure 12 This is a schematic diagram of the structure of the upper electrode mask template with the bottom facing upwards.

[0053] Figure 13 This is a cross-sectional schematic diagram of the high-frequency product wafer assembled according to the present invention (the upper electrode mask has been changed).

[0054] Figure 14 This is a schematic diagram of the front view of the lower electrode mask template of the present invention;

[0055] Figure 15 This is a schematic diagram of the structure of the lower electrode mask template with the front side facing up in this invention;

[0056] Figure 16 This is a cross-sectional schematic diagram of the high-frequency product wafer assembled according to the present invention (the lower electrode mask has been changed).

[0057] Figure 17 This is a cross-sectional schematic diagram of the high-frequency product wafer assembled according to the present invention (both the upper and lower electrode masks are changed).

[0058] Figure 18 This is a schematic diagram showing the coating completed according to the present invention;

[0059] Figure 19 This is a process flow diagram of Embodiment 1 of the present invention;

[0060] Figure 20 This is a flowchart of S10 of Embodiment 1 of the present invention;

[0061] Figure 21 This is a process flow diagram of Embodiment 2 of the present invention;

[0062] Figure 22 This is a heat treatment flow chart of Embodiment 3 of the present invention;

[0063] Figure 23 This is a heat treatment flow chart of Embodiment 4 of the present invention;

[0064] Figure 24 This is a flowchart of S10 of Embodiment 5 of the present invention;

[0065] Figure 25 This is a flowchart of S10 of Embodiment 6 of the present invention;

[0066] In the figure: 1. Wafer, 2. Lower electrode mask, 3. Positioning plate, 4. Wafer positioning groove, 5. Upper electrode mask, 6. Positioning hole, 7. Electrode hole, 8. Upper electrode diffusion protrusion, 9. Lower electrode diffusion protrusion, 10. Lower deposition balance plate, 11. Upper deposition balance plate, 12. Lower balance via, 13. Upper balance via. Detailed Implementation

[0067] The invention will now be further described with reference to the accompanying drawings.

[0068] Please refer to Figures 5-7 , Figure 5 This is a schematic diagram illustrating the state between the electrode mask and the wafer after assembling a high-frequency crystal resonator in a crystal resonator sputtering coating apparatus, which is part of the background technology of this invention. Figure 6 This is a schematic diagram illustrating another state between the electrode mask and the wafer after the high-frequency crystal resonator is assembled in the crystal resonator sputtering coating apparatus of this invention. Figure 7 This is a schematic diagram of another state between the electrode mask and the wafer after the high-frequency crystal resonator is assembled in the crystal resonator sputtering coating device.

[0069] Figure 5 In the middle, after the wafer 1 is assembled, it is close to the lower electrode mask 2, and there is a gap between the wafer 1 and the upper electrode mask 5; Figure 6 In the process, after the wafer 1 is assembled, the distance between it and the lower electrode mask 2 and the upper electrode mask 5 is basically the same (i.e., the wafer 1 is centered), and there are gaps between the wafer 1 and the lower electrode mask 2, and between the wafer 1 and the upper electrode mask 5. Figure 7 In the process, after the wafer 1 is assembled, it is close to the upper electrode mask 5, and there is a gap between the wafer 1 and the lower electrode mask 2.

[0070] Figure 5 In the assembly of the crystal resonator sputtering coating equipment, during the production of high-frequency products, electrode particles (target particles) diffuse through the gap into areas outside the electrode hole 7 during the coating process. Figure 8 As shown, Figure 8The circle with the arrow indicates the diffusion area. After coating, the electrode area of ​​the upper electrode is larger than that of the lower electrode (designed electrode area), and the areas of the upper and lower electrodes are asymmetrical, which ultimately affects the performance parameters of the product.

[0071] Figure 6 In the assembly of the crystal resonator sputtering coating equipment, during the production of high-frequency products, electrode particles (target particles) diffuse through the gap into areas outside the electrode hole 7 during the coating process. Figure 9 As shown, Figure 9 The circle with the arrow indicates the diffusion area. After the coating is completed, the electrode area of ​​the upper and lower electrodes is larger than the designed electrode area, which ultimately affects the product's performance parameters.

[0072] Figure 7 In the assembly of the crystal resonator sputtering coating equipment, during the production of high-frequency products, electrode particles (target particles) diffuse through the gap into areas outside the electrode hole 7 during the coating process. Figure 10 As shown, Figure 10 The circle with the arrow indicates the diffusion area. After coating, the electrode area of ​​the lower electrode is larger than that of the upper electrode (designed electrode area), and the areas of the upper and lower electrodes are asymmetrical, which ultimately affects the performance parameters of the product.

[0073] against Figures 8-9 To address the problem, this invention improves upon existing crystal resonator sputtering coating apparatuses. Even when the positioning plate 3 cannot be made thinner, it ensures a smaller gap between the electrode hole 7 and the wafer 1, reducing or eliminating diffusion during coating. This prevents asymmetry between the upper and lower electrodes or the upper and lower electrode areas exceeding the design area, thus avoiding impacts on product performance parameters.

[0074] Please refer to this again. Figures 1-3 and reference Figures 11-13 , Figure 11 This is a front view of the upper electrode mask template of the present invention. Figure 12 This is a schematic diagram of the structure of the upper electrode mask template with the bottom facing upwards (i.e., the surface adjacent to the wafer facing upwards). Figure 13 This is a cross-sectional schematic diagram of the high-frequency product wafer assembled according to the present invention (the upper electrode mask has been changed).

[0075] A crystal resonator sputtering coating apparatus includes, in sequence, a base plate, a lower electrode mask 2, a positioning plate 3, an upper electrode mask 5, and a magnetic cover plate. The base plate is provided with positioning posts. Positioning holes 6, allowing the positioning posts to pass through, are provided on the lower electrode mask 2, positioning plate 3, upper electrode mask 5, and magnetic cover plate. A wafer positioning groove 4 is provided on the positioning plate 3, and a wafer 1 is installed in the wafer positioning groove 4. Electrode holes 7 are provided on both the upper electrode mask 5 and the lower electrode mask 2. The thickness of the positioning plate 3 is denoted as [missing information]. , =0.04mm, the upper electrode mask 5 has an upper electrode diffusion protrusion 8 on the side facing the wafer 1 to prevent the diffusion of upper electrode particles during coating. The upper electrode diffusion protrusion 8 is located in the wafer positioning groove 4 during assembly. The thickness of the upper electrode diffusion protrusion 8 is denoted as . The thickness of wafer 1 is denoted as 0.017mm ≤ <0.04mm, The size of the upper electrode blocking protrusion 8 matches the size of the wafer positioning groove 4.

[0076] from Figure 13 Yes, after assembly, there is basically no gap between the wafer 1 and the upper electrode mask 5 and the lower electrode mask 2 (as can be seen from the circled area with arrows in the figure).

[0077] Please refer to this again. Figures 1-3 and reference Figures 14-16 , Figure 14 This is a front view of the lower electrode mask template of the present invention. Figure 15 This is a schematic diagram of the structure of the lower electrode mask template with the front side facing up. Figure 16 This is a cross-sectional schematic diagram of the high-frequency product wafer assembled according to the present invention (the lower electrode mask has been changed).

[0078] A crystal resonator sputtering coating apparatus includes, in sequence, a base plate, a lower electrode mask 2, a positioning plate 3, an upper electrode mask 5, and a magnetic cover plate. The base plate is provided with positioning posts. Positioning holes 6, allowing the positioning posts to pass through, are provided on the lower electrode mask 2, positioning plate 3, upper electrode mask 5, and magnetic cover plate. A wafer positioning groove 4 is provided on the positioning plate 3, and a wafer 1 is installed in the wafer positioning groove 4. Electrode holes 7 are provided on both the upper electrode mask 5 and the lower electrode mask 2. The thickness of the positioning plate 3 is denoted as [missing information]. , =0.04mm, the lower electrode mask 2 has a lower electrode diffusion protrusion 9 on the side facing the wafer 1 to prevent the diffusion of lower electrode particles during coating. The lower electrode diffusion protrusion 9 is located in the wafer positioning groove 4 during assembly. The thickness of the lower electrode diffusion protrusion 9 is denoted as . The thickness of wafer 1 is denoted as 0.017mm ≤ <0.04mm, The size of the lower electrode blocking protrusion 9 matches the size of the wafer positioning groove 4.

[0079] from Figure 16 Yes, after assembly, there is basically no gap between the wafer 1 and the upper electrode mask 5 and the lower electrode mask 2 (as can be seen from the circled area with arrows in the figure).

[0080] Please refer to this again. Figures 1-3 , Figure 11 , Figure 12 , Figure 14 and Figure 15 and reference Figure 17 , Figure 17 This is a cross-sectional schematic diagram of the high-frequency product wafer assembled according to the present invention (both the upper and lower electrode masks have been changed).

[0081] A crystal resonator sputtering coating apparatus includes, in sequence, a base plate, a lower electrode mask 2, a positioning plate 3, an upper electrode mask 5, and a magnetic cover plate. The base plate is provided with positioning posts. Positioning holes 6, allowing the positioning posts to pass through, are provided on the lower electrode mask 2, positioning plate 3, upper electrode mask 5, and magnetic cover plate. A wafer positioning groove 4 is provided on the positioning plate 3, and a wafer 1 is installed in the wafer positioning groove 4. Electrode holes 7 are provided on both the upper electrode mask 5 and the lower electrode mask 2. The thickness of the positioning plate 3 is denoted as [missing information]. , =0.04mm, the upper electrode mask 5 has an upper electrode diffusion protrusion 8 on the side facing the wafer 1 to prevent the diffusion of upper electrode particles during coating. The upper electrode diffusion protrusion 8 is located in the wafer positioning groove 4 during assembly. The thickness of the upper electrode diffusion protrusion 8 is denoted as . The lower electrode mask 2, facing the wafer 1, has a lower electrode diffusion protrusion 9 to prevent the diffusion of lower electrode particles during coating. The lower electrode diffusion protrusion 9 is located within the wafer positioning groove 4 during assembly. The thickness of the lower electrode diffusion protrusion 9 is denoted as... The thickness of wafer 1 is denoted as 0.017mm ≤ <0.04mm, The size of the upper electrode blocking protrusion 8 matches the size of the wafer positioning groove 4, and the size of the lower electrode blocking protrusion 9 matches the size of the wafer positioning groove 4.

[0082] from Figure 17 Yes, after assembly, there is basically no gap between the wafer 1 and the upper electrode mask 5 and the lower electrode mask 2 (as can be seen from the circled area with arrows in the figure).

[0083] When the crystal resonator sputtering coating apparatus of the present invention is assembled and used in the production of high-frequency products, during the coating process, because there are no gaps, the electrode particles (target particles) cannot diffuse into areas outside the electrode holes 7. Figure 18 As shown, Figure 18 There are no electrode particles in the circle with the arrow in the middle. After the coating is completed, the upper and lower areas are basically the same as the design. This embodiment effectively reduces the gap between the wafer and the upper and lower electrode masks, thus solving the electrode diffusion problem during high-frequency wafer coating.

[0084] In one or more specific embodiments of this example, wafer 1 is preferably a quartz wafer.

[0085] In one or more specific embodiments of this example, the electrode particles are silver particles or gold particles.

[0086] In one or more specific embodiments of this example, the upper electrode mask 5 and the lower electrode mask 2 are made of stainless steel.

[0087] In the prior art, the upper electrode mask 5 or the lower electrode mask 2 is etched by a full etching method. That is, a substrate, such as a stainless steel substrate with a thickness of 0.08 mm, is taken and the positioning holes 6 and electrode holes 7 are formed on the substrate by etching. The method of forming the positioning holes 6 and electrode holes 7 can be the pattern conversion method commonly used in the field of integrated manufacturing (i.e., film application, exposure, development, etching, and film removal). After the full etching method, the thickness of the substrate remains unchanged, and the thickness of the area of ​​the substrate corresponding to the wafer 1 is the same as the thickness of other areas.

[0088] In this embodiment, the upper electrode mask 5 or the lower electrode mask 2 is etched by a semi-etching method. The pattern conversion method of etching is the same as the existing full etching method. The only difference is that after etching, the thickness of the area corresponding to the substrate and the wafer 1 is the same as that of the substrate before etching, while the thickness of the substrate in other areas is less than that of the substrate before etching.

[0089] Example 1

[0090] The process flow of this embodiment is as follows: Figure 19 .

[0091] A method for fabricating a crystal resonator by sputtering includes the following steps:

[0092] S0, the wafer 1 to be coated is installed in the crystal resonator sputtering coating apparatus of the present invention, and then the crystal resonator sputtering coating apparatus is installed in a magnetron sputtering machine. The crystal resonator sputtering coating apparatus is installed vertically, and the thickness of the wafer 1 to be coated is 0.020 mm.

[0093] S1, sputtering coating, the target thickness of the film is 150nm. The film consists of a transition layer and a gold layer. The target thickness of the transition layer (i.e. the bottom layer) is 10nm. During sputtering, the material of the transition layer is first sputtered on wafer 1 to form the transition layer, and then gold is sputtered to form the gold layer. The material of the transition layer is titanium.

[0094] S3, divide wafer 1 to form individual "bare crystal oscillator" chips.

[0095] S4, Assembly, Dispensing and Patch Installation.

[0096] S5, Curing. Curing is carried out in a curing oven under the following conditions: temperature is increased from room temperature to 150°C at a rate of 2°C / min, maintained at 150°C for 90 minutes, and then allowed to cool naturally to room temperature. The curing atmosphere is air. In this invention, the purpose of curing is twofold: firstly, to cure the conductive silver paste, and secondly, to eliminate stress in the assembled structure and improve overall performance.

[0097] S6, wire bonding and sealing.

[0098] S7, final electrical performance test.

[0099] S8, laser marking: The final electrical performance test parameters qualified products (i.e., resonators) are moved to the laser marking row position by the transfer robotic arm for laser marking; the transfer robotic arm picks up four resonators at a time and marks four resonators at a time.

[0100] S9, Initial tape feeding: The transfer robot arm moves the marked resonator into the tape feeding machine; after each marking, the transfer robot arm moves the marked resonator into the tape feeding machine and places the resonator into the tape feeding grid (one resonator per grid).

[0101] S10, Inspect the marking marks to confirm their quality; the marking marks are inspected using a CCD (camera) mounted above the tape. An image is taken when the marked resonator moves below the CCD within the tape. Figure 20 This includes the following steps:

[0102] S101, the CCD takes a picture of the marking mark on the resonator. The server receives the picture information from the CCD and makes a judgment on whether the marking mark is qualified and displays it on the display device. If the judgment is qualified, proceed to S11; if the judgment is unqualified, proceed to S102.

[0103] S102, the server simultaneously sends an alarm command and sends a command to the actuator, which moves the light panel inward to expose the resonator on the tape that failed the marking inspection.

[0104] S103, the operator manually removes the defective resonator with tweezers, then uses tweezers to place a qualified resonator into the tape. The actuator resets the lamp board and proceeds to S11.

[0105] S11, continue weaving.

[0106] S12, Packaging.

[0107] The crystal resonator sputtering coating device used in this embodiment is the crystal resonator sputtering coating device of the present invention. After coating, the upper and lower areas are basically the same as the design, which solves the problem of electrode diffusion during high-frequency wafer coating. After coating, no frequency tuning is required, and the performance is the same as that of the bulk resonator sputtering coating device in the prior art after coating and frequency tuning.

[0108] In this embodiment, the actuator for moving and resetting the lamp panel is an existing mechanism, which can be a cylinder with a pushing mechanism or a motor with a pushing mechanism. No special provisions are made here, and those skilled in the art can choose according to their needs.

[0109] Example 2

[0110] Although the process of Example 1 can produce high-frequency resonators with a wafer thickness of less than 0.04 mm without frequency tuning, the performance of the high-frequency resonators produced in Example 1 still needs to be improved, and the long-term reliability of the high-frequency resonators produced in Example 1 needs to be improved.

[0111] The process flow diagram of this embodiment is as follows: Figure 21 .

[0112] Compared with Example 1, this embodiment differs in that S2 is added between S1 and S3. S2 is a heat treatment step, and the heat treatment conditions are: the temperature is raised from room temperature to 400°C at a rate of 10°C / minute, held for 30 minutes, cooled in the furnace, and the heat treatment atmosphere is nitrogen. The heat treatment is carried out in a heat treatment furnace.

[0113] Example 3

[0114] Although Example 2 improves the long-term reliability of the high-frequency resonator, further improvements are still needed.

[0115] The difference between this embodiment and embodiment 2 is that in S2, the heat treatment conditions are: the temperature is raised from room temperature to 200°C at a rate of 10°C / minute, then raised from 200°C to 400°C at a rate of 5°C / minute, held for 30 minutes, cooled in the furnace, the heat treatment atmosphere is nitrogen, and the heat treatment is carried out in a heat treatment furnace.

[0116] The heat treatment process in this embodiment is as follows: Figure 22 .

[0117] Example 4

[0118] The difference between this embodiment and embodiment 2 is that in S2, the heat treatment conditions are: the temperature is raised from room temperature to 400°C at a rate of 5°C / minute, held for 30 minutes, cooled with the furnace, the heat treatment atmosphere is nitrogen, and the heat treatment is carried out in a heat treatment furnace.

[0119] The heat treatment process in this embodiment is as follows: Figure 23 .

[0120] Ten high-frequency resonators were randomly selected from each of the qualified ones produced in Examples 1-4 and subjected to high-temperature aging tests. The high-temperature aging parameters were: 125°C for 168 hours, with the rated excitation power (or slightly lower than the rated power) applied to keep them in an oscillating state. The results are shown in Table 1 below.

[0121] Table 1 High-Temperature Aging Effect Table

[0122] As can be seen from Table 1, compared with Example 1, Example 2 showed a significant reduction in both frequency aging drift and resistance aging drift after the addition of heat treatment; compared with Examples 2 and 4, Example 3 showed a significant reduction in both frequency aging drift and resistance aging drift under the heat treatment conditions of Example 3 compared with the heat treatment conditions of Example 2 or Example 4; and the frequency aging drift and resistance aging drift under the heat treatment conditions of Example 4 were not significantly different from those under the heat treatment conditions of Example 2.

[0123] Example 5

[0124] Although the process in Example 1 can produce high-frequency resonators with a wafer thickness of less than 0.04mm without frequency tuning, the production method in Example 1 uses manual tape reeling when an alarm for non-conforming marking occurs. However, manual tape reeling has the following drawbacks: (1) it requires stopping the equipment, affecting equipment efficiency; (2) manually replacing non-conforming markings with conforming markings carries the risk of incorrect placement or / and incorrect material placement (not the product required by the customer), resulting in customer complaints (in fact, this operation has indeed caused customer complaints).

[0125] The difference between this embodiment and embodiment 1 is that the flowchart of S10 is as follows: Figure 24 This includes the following steps:

[0126] S101, the CCD takes a picture of the marking mark on the resonator. The server receives the picture information from the CCD and makes a judgment on whether the marking mark is qualified and displays it on the display device. If the judgment is qualified, proceed to S11; if the judgment is unqualified, proceed to S102.

[0127] S102, the server simultaneously issues an alarm command and sends a command to the actuator. The actuator moves the light panel inward to expose the resonator on the tape that failed the marking inspection. The server also sends a replacement command to the transfer robot arm.

[0128] S103, after receiving the replacement instruction, the transfer robot arm takes the unqualified resonator out of the tape grid and puts it into the collection box, and picks one of the marked resonators from the laser marking column position and puts it into the grid. The actuator resets the light board and enters S11.

[0129] This embodiment improves production efficiency and reduces the risk of customer complaints by replacing manual replacement of defective crystal resonators with intelligent replacement of defective crystal resonators.

[0130] Example 6

[0131] Although Example 5 improved production efficiency and reduced the risk of customer complaints by replacing manual replacement of defective crystal resonators with intelligent replacement, the lack of inspection of whether the marked resonators were qualified when picking them up from the laser marking row position still posed a risk of defective marking.

[0132] The difference between this embodiment and embodiment 5 is that the flowchart of S10 is as follows: Figure 25 This includes the following steps:

[0133] S101, the CCD takes a picture of the marking mark on the resonator. The server receives the picture information from the CCD and makes a judgment on whether the marking mark is qualified and displays it on the display device. If the judgment is qualified, proceed to S11; if the judgment is unqualified, proceed to S102.

[0134] S102, the server simultaneously issues an alarm command and sends a command to the actuator. The actuator moves the light panel inward to expose the resonator on the tape that failed the marking inspection. The server also sends a replacement command to the transfer robot arm.

[0135] S103: After receiving the replacement command, the transfer robotic arm removes the unqualified resonator from the tape tray and places it into the collection box. It also picks up one of the marked resonators from the laser marking column and places it into the corresponding slot. The CCD takes a picture of the marking mark on the replaced resonator. The server receives the CCD's picture information and determines whether the marking mark is qualified, displaying the result on the display device. If the mark is qualified, the actuator resets the light board and proceeds to S11. If the mark is unqualified, this step is repeated until the mark is qualified. The actuator then resets the light board and proceeds to S11.

[0136] This embodiment completely prevents unqualified crystal resonators from entering the packaging process.

[0137] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for fabricating a crystal resonator without frequency modulation, characterized in that, Includes the following steps: S0, the wafer (1) is installed in the crystal resonator sputtering coating apparatus and then placed in the magnetron sputtering machine; S1, film deposition, with a target film thickness of 100nm~200nm, the film consists of a transition layer and a gold layer, wherein the target thickness of the transition layer is 5nm~15nm; S3, divide the wafer (1) to form a bare crystal oscillator chip; S4, assembly, dispensing and mounting; S5, Curing, curing is carried out in a curing oven; S6, wire bonding and sealing; S7, final electrical performance test; S8, laser marking; S9, first time lacing; S10, Check the markings; S11, continue weaving; S12, Packaging; The crystal resonator sputtering coating apparatus sequentially includes a base plate, a lower electrode mask (2), a positioning plate (3), an upper electrode mask (5), and a magnetic cover plate. The positioning plate (3) is provided with a wafer positioning groove (4), and the wafer (1) is installed in the wafer positioning groove (4). Both the upper electrode mask (5) and the lower electrode mask (2) are provided with electrode holes (7). The thickness of the positioning plate (3) is denoted as h. 定 Of the two plates, the upper electrode mask (5) and the lower electrode mask (2), at least one plate has a diffusion protrusion on the side facing the wafer (1) to prevent the diffusion of electrode particles during coating. The size of the diffusion protrusion matches the size of the wafer positioning groove (4). The diffusion protrusion is located inside the wafer positioning groove (4) during assembly. The thickness of the wafer (1) is denoted as h. 晶 0.017mm ≤h 晶 <h 定 ; When the dispersion protrusion is the upper electrode dispersion protrusion (8), the upper electrode dispersion protrusion (8) is located on the upper electrode mask (5), and the thickness of the upper electrode dispersion protrusion (8) is denoted as h. 上 h 上 +h 晶 = h 定 ;or When the dispersion protrusion is the lower electrode dispersion protrusion (9), the lower electrode dispersion protrusion (9) is located on the lower electrode mask (2), and the thickness of the lower electrode dispersion protrusion (9) is denoted as h. 下 h 下 +h 晶 = h 定 ;or When the diffusion protrusion includes an upper electrode diffusion protrusion (8) and a lower electrode diffusion protrusion (9), the upper electrode diffusion protrusion (8) is located on the upper electrode mask (5), and the thickness of the upper electrode diffusion protrusion (8) is denoted as h. 上 The lower electrode dispersion protrusion (9) is located on the lower electrode mask (2), and the thickness of the lower electrode dispersion protrusion (9) is denoted as h. 下 h 上 +h 下 +h 晶 = h 定 .

2. The method for fabricating a crystal resonator without frequency modulation according to claim 1, characterized in that, The curing conditions are as follows: the temperature is increased from room temperature to 150°C at a rate of 2°C / min, maintained at 150°C for 90 minutes, and then naturally cooled to room temperature. The curing atmosphere is air.

3. The method for fabricating a crystal resonator without frequency modulation according to claim 1, characterized in that, After S1 and before S3, it also includes S2, heat treatment; the heat treatment conditions are: heating from room temperature to 350℃~450℃ at a rate of 5℃ / min~15℃ / min, holding at that temperature for 20 minutes~45 minutes, cooling with the furnace, and the heat treatment atmosphere is nitrogen.

4. The method for fabricating a crystal resonator without frequency modulation according to claim 1, characterized in that, After S1 and before S3, it also includes S2, heat treatment; the heat treatment conditions are: rising from room temperature to 200℃ at a rate of 10℃ / min, then rising from 200℃ to 400℃ at a rate of 5℃ / min, holding for 30 minutes, cooling with the furnace, and the heat treatment atmosphere is nitrogen.

5. The method for fabricating a crystal resonator without frequency modulation according to any one of claims 1-4, characterized in that, S10 includes the following steps: S101, the CCD takes a picture of the marking mark on the resonator. The server receives the picture information from the CCD and makes a judgment on whether the marking mark is qualified and displays it on the display device. If the judgment is qualified, proceed to S11; if the judgment is unqualified, proceed to S102. S102, the server simultaneously issues an alarm command and sends a command to the actuator. The actuator moves the light panel inward to expose the resonator on the tape that failed the marking inspection. The server also sends a replacement command to the transfer robot arm. S103, after receiving the replacement instruction, the transfer robot arm takes the unqualified resonator out of the tape grid and puts it into the collection box, and picks one of the marked resonators from the laser marking column position and puts it into the grid. The actuator resets the light board and enters S11.

6. The method for fabricating a crystal resonator without frequency modulation according to any one of claims 1-4, characterized in that, S10 includes the following steps: S101, the CCD takes a picture of the marking mark on the resonator. The server receives the picture information from the CCD and makes a judgment on whether the marking mark is qualified and displays it on the display device. If the judgment is qualified, proceed to S11; if the judgment is unqualified, proceed to S102. S102, the server simultaneously issues an alarm command and sends a command to the actuator. The actuator moves the light panel inward to expose the resonator on the tape that failed the marking inspection. The server also sends a replacement command to the transfer robot arm. S103: After receiving the replacement command, the transfer robotic arm removes the unqualified resonator from the tape tray and places it into the collection box. It also picks up one of the marked resonators from the laser marking column and places it into the corresponding slot. The CCD takes a picture of the marking mark on the replaced resonator. The server receives the CCD's picture information and determines whether the marking mark is qualified, displaying the result on the display device. If the mark is qualified, the actuator resets the light board and proceeds to S11. If the mark is unqualified, this step is repeated until the mark is qualified. The actuator then resets the light board and proceeds to S11.

7. The method for fabricating a crystal resonator without frequency modulation according to claim 1, characterized in that, h 定 =0.04mm。

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