WO2024027737A1

WO2024027737A1 - Quartz resonator having sandwich structure formed by double base plates and piezoelectric layer, and electronic device

Info

Publication number: WO2024027737A1
Application number: PCT/CN2023/110651
Authority: WO
Inventors: 庞慰; 张孟伦
Original assignee: 天津大学
Priority date: 2022-08-05
Filing date: 2023-08-02
Publication date: 2024-02-08
Also published as: CN117559943A

Abstract

The present invention relates to a quartz resonator, comprising a bottom electrode, a top electrode and a quartz piezoelectric layer, the quartz piezoelectric layer having an inverted highly-protruded structure comprising bosses; a packaging structure, comprising a first packaging substrate, a second packaging substrate and a bonding sealing layer, the bonding sealing layer comprising a piezoelectric layer packaging portion, the piezoelectric layer packaging portion being a part of the quartz piezoelectric layer, and the piezoelectric layer packaging portion comprising the bosses. The first packaging substrate and the second packaging substrate are respectively bonded to the bosses on the two sides of the quartz piezoelectric layer so as to form a sandwich structure comprising the first packaging substrate, the quartz piezoelectric layer and the second packaging substrate. The present invention also relates to an electronic device.

Description

Quartz resonators and electronic devices with a sandwich structure formed by double substrates and piezoelectric layers

Technical field

Embodiments of the present invention relate to the field of semiconductors, and in particular to a quartz resonator in which a double substrate and a piezoelectric layer form a sandwich structure, and an electronic device.

Background technique

High fundamental frequency, miniaturization and low profile are the development trends of quartz crystal oscillators (hereinafter referred to as wafers). Traditional wafer manufacturing solutions mostly use grinding and slicing to obtain granular flakes of a certain frequency, and then perform subsequent electrode plating and frequency modulation. However, the wire cutting technology used in slicing is difficult to achieve for sizes of 1mm×1mm and below. It is basically unable to cover the manufacturing of wafers with sizes of 1.2mm×1.0mm and below, and it cannot meet the manufacturing requirements for wafers with sizes of 1.0mm×0.8mm and below. The fundamental frequency of the chip is mainly determined by the thickness of the resonance area of the chip. The fundamental frequency of the chip is governed by the following formula:
f ₀ (MHz)＝1670(MHz·μm)/d(μm) (1)

Wafer-level manufacturing can significantly reduce the manufacturing cost of a single resonator and achieve consistent quality control between resonators; generally speaking, the larger the wafer size, the lower the manufacturing cost of a single resonator.

However, for wafer-level manufacturing solutions, where hundreds to thousands of wafers are arranged on a single wafer, precise control of the quartz thickness at each location is a huge challenge, which directly leads to changes in the frequency of the wafers on the entire wafer. Accuracy and consistency cannot be guaranteed. Therefore, there are great challenges in wafer-level chip frequency modulation. The current methods adopted by existing technologies mainly focus on using grinding technology with ultra-high-precision film thickness monitoring systems to prepare quartz films with a thickness uniformity within a few nanometers. This frequency control and adjustment technology places extremely high requirements on materials and manufacturing processes. The larger the wafer area, the higher the manufacturing difficulty, which hinders The generation of low-cost, high-efficiency manufacturing solutions.

In addition, it is also hoped that on the basis of manufacturing a single resonator at the wafer level, the boundary conditions of the resonator can be optimized and the lateral leakage of acoustic waves can be reduced, thereby further improving the performance of the resonator. However, it is difficult to optimize the boundary conditions of the resonator through the existing mechanical grinding thinning method.

In the existing sandwich structure, the resonator adopts a cantilever beam structure, which reduces the mechanical stability of the resonator. In addition, mechanical grinding is used to create the resonance area in the existing technology, which limits the scale of wafer-level manufacturing (it is difficult to achieve more than two inches). wafer manufacturing).

Contents of the invention

In order to alleviate or solve at least one aspect of the above-mentioned problems in the prior art, the present invention is proposed.

According to an aspect of an embodiment of the present invention, a quartz resonator is proposed, including:

A bottom electrode, a top electrode and a quartz piezoelectric layer. The quartz piezoelectric layer is an inverted platform structure including a boss;

a packaging structure, including a first packaging substrate, a second packaging substrate and a bonding sealing layer,

in:

The joint sealing layer includes a piezoelectric layer encapsulation part, the piezoelectric layer encapsulation part is a part of the quartz piezoelectric layer, and the piezoelectric layer encapsulation part includes the boss;

The first packaging substrate and the second packaging substrate are respectively joined to the bosses on both sides of the quartz piezoelectric layer to form a sandwich structure including the first packaging substrate, the quartz piezoelectric layer, and the second packaging substrate. .

Embodiments of the present invention also relate to a method for manufacturing a quartz resonator, including the steps:

Provide quartz wafers;

Forming a quartz piezoelectric layer on a quartz wafer includes the steps of: using at least micro/nano electromechanical system photolithography technology to form a quartz piezoelectric layer corresponding to a plurality of quartz resonators on the quartz wafer, and the quartz piezoelectric layer includes: The anti-high platform structure of the boss is suitable for disposing a first electrode layer including a first electrode and a second electrode layer including a second electrode on both sides of the quartz piezoelectric layer;

A first packaging substrate and a second packaging substrate are provided, and the first packaging substrate and the second packaging substrate are respectively joined to the boss on both sides of the quartz piezoelectric layer to form a package including the first packaging substrate, quartz A sandwich structure of the piezoelectric layer and the second packaging substrate, the first packaging substrate is opposite to the first electrode layer, and the second packaging substrate is opposite to the second electrode layer; and

Divide: after forming the sandwich structure, at least cut or split the sandwich structure, To form multiple mechanically separated sandwich structure particles.

Embodiments of the present invention also relate to an electronic device, including the above-mentioned quartz resonator.

Description of the drawings

These and other features and advantages of various disclosed embodiments of the present invention may be better aided in understanding by the following description and accompanying drawings, in which like reference numerals refer to like parts throughout, wherein:

1-14 are schematic cross-sectional views of the manufacturing process of a quartz resonator according to an exemplary embodiment of the present invention;

Figure 15 is a schematic cross-sectional view of a packaging structure of a quartz resonator according to another exemplary embodiment of the present invention;

16-35 are schematic cross-sectional views of the manufacturing process of a quartz resonator according to yet another exemplary embodiment of the present invention;

36-38 are schematic cross-sectional views of a packaging structure of a quartz resonator according to another exemplary embodiment of the present invention;

39-49 are schematic cross-sectional views of the manufacturing process of a quartz resonator structure according to an exemplary embodiment of the present invention;

Figure 50 is a schematic flow chart of fundamental frequency adjustment in the resonance area of a quartz wafer;

Figure 51 is a schematic flowchart of resonant frequency adjustment of a quartz resonator.

Detailed ways

The technical solution of the present invention will be further described in detail below through examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numbers indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the general inventive concept of the present invention and should not be understood as a limitation of the present invention. Some, but not all, embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of the present invention.

The present invention proposes a quartz wafer manufacturing process based on micro/nano electromechanical systems (M/NEMS) photolithography technology, which can be used to produce small-sized, frequency-accurate quartz resonators.

In the present invention, a wafer-level frequency/thickness monitoring and control method is adopted, which reduces the requirements for the uniformity of quartz wafer thickness processing and reduces the processing difficulty. This program is suitable for the production of quartz wafers in different frequency bands. It is universally applicable and is not limited by the quartz wafer area, which has obvious advantages.

In the present invention, a sandwich structure is adopted, which is beneficial to miniaturization and flattening of the resonator.

In the present invention, a quartz piezoelectric layer with an anti-platform structure is manufactured on a quartz wafer based on micro/nano electromechanical systems (M/NEMS) photolithography technology, which is beneficial to optimizing the boundary conditions of the quartz resonator and reducing lateral leakage of sound waves. , which is conducive to improving the performance of quartz resonators.

The present invention's wafer manufacturing solution based on micro-nano electromechanical systems (M/NEMS) makes full use of the advantages of MEMS photolithography technology and wafer-level process manufacturing methods, and uses the method of wet etching wafer contours to get rid of the impact of cutting technology on wafer size. Limitation, can realize the processing of smaller size wafers of 1210, 1008 and below. In addition, wafer processing solutions for wafer manufacturing can improve dimensional processing accuracy and improve wafer processing efficiency.

The present invention proposes a wafer-level wafer manufacturing and frequency control process, which eliminates the need for ultra-high-precision grinding technology for quartz wafers, and at the same time greatly reduces the difficulty of frequency modulation, making frequency modulation completely unconstrained by wafer area expansion. At the same time, this solution meets the requirements for miniaturized manufacturing of wafers from low frequency to high frequency (30-300MHz) and ultra-high frequency (300MHz-3GHz), and is of great significance to promoting the development of the quartz wafer field.

The manufacturing process of the quartz resonator according to the present invention is illustrated below with reference to FIGS. 1-51. In the present invention, the reference signs are schematically explained as follows:

10: Quartz wafer or wafer.

12: Resonance area.

14: Through hole etching area or through hole.

14’: Through hole etching area.

16: Piezoelectric layer encapsulation department.

18: Anti-high platform.

20, 20A, 20B, 20C: mask layer or mask.

22: Mask slot or mask opening.

30: Top electrode, the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or composites of the above metals or their alloys, etc.

32: The electrical connection part of the top electrode. The material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or composites of the above metals or their alloys. In alternative embodiments, the top electrode and its electrical connections, the bottom electrode and its electrical connections may be the same metal material.

40: Bottom electrode, the material can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or Compounds of the above metals or their alloys, etc.

50: First packaging substrate or first packaging quartz wafer.

52: First cavity.

54: First conductive via hole or first package substrate conductive via hole.

60: Second packaging substrate or second packaging quartz wafer.

62: Second cavity.

64: Second conductive via hole or second package substrate conductive via hole.

72A, 72B: Metal bonding layer, which can be gold-gold, gold-tin, copper-tin bonding, etc.

74A, 74B: Filling metal layer. In an optional embodiment, the filling metal layer, the external connection part, the top electrode and its electrical connection part, the bottom electrode and its electrical connection part may be the same metal material.

In the specific embodiments of the present invention, each part is described using a feasible material as an example, but is not limited thereto.

1-14 are schematic cross-sectional views of a manufacturing process of a quartz resonator according to an exemplary embodiment of the present invention. In this embodiment, the resonant structure of the quartz resonator adopts a single-sided reverse platform structure. Compared with the flat structure of the piezoelectric layer, this structure has better structural stability, improves the impact resistance of the chip, and is also conducive to improving the resonator. boundary conditions to improve the performance of the resonator.

The following is an example of the manufacturing process of a quartz resonator with reference to Figures 1-14, which includes the following steps:

Step 1: Make mask 20A. As shown in FIG. 1 , a mask 20 is made on one side (for example, the front side) of a quartz wafer (for example, with a diameter of 1-8 inches and a thickness of 100 μm to 1 mm) using micro/nano electromechanical system photolithography. The mask 20A is patterned to form mask openings 22. Specifically, the through-hole etching region 14 and the resonant region 12 for preparation are exposed. A mask 20A is also provided on the other side of the quartz wafer 10 (for example, the secondary surface), covering the entire other side.

Here, for the subsequent use of wet etching (for example, step 2 of the embodiment shown in FIGS. 1 to 14 ), the mask may be a metal mask, such as chromium gold (a layer of gold on the top and a layer of chromium on the bottom), or other Inert metal; for subsequent use of dry etching (for example, step 2 of the embodiment shown in Figures 1 to 14), the mask can be SU-8 glue, or other photoresists suitable for dry etching. The material of the mask 20A can also be applied to other embodiments, which will not be described again below.

It should be noted that in FIGS. 1 to 14 , only the area corresponding to a single quartz resonator on the wafer is shown. As can be understood, there are multiple quartz resonators on the quartz wafer 10 as shown in FIGS. 1 to 14 Area. In other embodiments, similar understanding should be made, which will not be described again.

Step 2: Wet etching. As shown in Figure 2, the mask 20A is used as a barrier layer, and an etching liquid (such as an HF etching liquid with a temperature higher than 20°C and a concentration higher than 5%, or a HF/NH4F mixed etching liquid) is used to etch the quartz wafer. 10 Carry out etching. For example, under the action of high-temperature and high-concentration etching solutions, higher etching rates and steeper crystal plane slopes can be obtained. In FIG. 2 , a part of the resonance area of the quartz wafer is etched to form an anti-mountain 18 on the periphery of the resonance area to form an anti-mountain structure. Figure 2 shows a single-sided reverse elevated platform structure.

Although not shown, step 2 can also be replaced by dry etching, or wet etching can be combined with dry etching.

Step 3: Remove mask 20A. As shown in FIG. 3 , after the quartz wafer 10 is etched, it can be cleaned and dried, and then the mask 20A can be removed by wet etching.

Step 4: Make the top electrode. As shown in FIG. 4 , the resonator top electrode 30 is fabricated on the quartz wafer 10 by metal sputtering or evaporation. The top electrode 30 is composed of at least one layer of metal, and the metal in direct contact with the surface of the quartz wafer 10 may be chromium, titanium tungsten, molybdenum, gold, silver, etc. Top electrode 30 covers via etched area 14 .

Step 5: Join the first package substrate. As shown in FIG. 5 , align the quartz wafer 10 with the quartz wafer or the first packaging substrate 50 with the first cavity 52 etched in advance, so that the top electrode 30 is exactly located within the first cavity 52 . The first packaging substrate 50 and the quartz wafer 10 can be bonded together using a metal diffusion bonding method, which can be gold-gold, gold-tin, copper-tin bonding, or other methods. They can also be joined together in other ways, which are not limited here. The first packaging substrate 50 may also use other packaging materials.

In the embodiment of the present invention, when the first packaging substrate 50 is a quartz substrate, it may be a quartz wafer with a thickness of 20-300 μm and completely consistent with the wafer size specifications of the quartz wafer 10 .

In the embodiment shown in FIG. 5 , when the first packaging substrate 50 and the quartz wafer 10 are bonded with metal, a metal bonding layer is also provided at the junction between the first packaging substrate 50 and the quartz wafer 10 72A.

Step 6: Quartz wafer thinning. As shown in FIG. 6 , the quartz wafer 10 is thinned by grinding and polishing processes until the remaining thickness of the resonance region is within, for example, 1 μm compared with the design value (ie, the film thickness d ₀ mentioned above).

Step 7: Wafer-level film thickness measurement. The thickness of the polished quartz wafer in the resonant region was measured using optical methods. The measurement point must be selected in the area with the top electrode on the other side of the quartz film. As shown in Figure 7, the optical measurement method of transparent film thickness is used to measure the quartz film thickness in the resonance area of each wafer, and the difference between it and the design value _d0 is obtained, which provides a basis for the next step of adjusting the film thickness of each wafer. according to.

Step 8: Adjust quartz film thickness. As shown in Figure 8, the quartz plate in the resonance area of the wafer is etched twice using ion beam etching or wet etching. Repeat the operations in Figure 7 and Figure 8 to adjust the thickness of the wafer multiple times to finally obtain a precise thickness. This process can be seen in Figure 50.

Step 9: Set a through-hole perforation mask 20B on the upper surface of the structure shown in Figure 8. As shown in Figure 9, the mask 20B is provided with mask openings at positions corresponding to the through-hole etching areas 14.

Step 10: For example, dry etching is used to etch the portion of the quartz wafer 10 located at the through-hole etching area 14 to form the through-hole 14 through the through-hole etching area 14, as shown in FIG. 10 .

Step 11: Remove mask 20B. After step 10, the mask 20B can be removed by wet etching to obtain the structure as shown in FIG. 11.

Step 12: Make the bottom electrode and electrical connections. As shown in FIG. 12 , the resonator bottom electrode 40 and the electrical connection portion 32 are fabricated on the quartz wafer 10 by metal sputtering or evaporation. The bottom electrode 40 is composed of at least one layer of metal, and the metal in direct contact with the surface of the quartz wafer 10 should be chromium, titanium tungsten, molybdenum, gold, silver, etc. The electrical connection portion 32 is electrically connected to the metal in the via etching area 14, and is disposed on the same side of the quartz wafer 10 as the bottom electrode 40 and is spaced apart from each other.

Step 13: Frequency measurement and frequency modulation. As shown in FIG. 13 , the measured resonant frequency f of the quartz resonator is smaller than the predetermined resonant frequency f ₀ . For example, the quality of the top electrode 30 can be changed by using a particle beam to improve the quartz resonator. The resonant frequency of the resonator. As can be understood, when the measured resonant frequency meets the set frequency, the frequency modulation step does not need to be performed. This process can be seen in Figure 41.

Step 14: Bond the second package substrate. As shown in FIG. 14 , align the quartz wafer 10 in step 13 with the quartz wafer or the second packaging substrate 60 with the second cavity 62 pre-etched, so that the bottom electrode 40 is exactly located between the second cavity 62 Inside. The second packaging substrate 60 and the quartz wafer 10 can be bonded together using a metal diffusion bonding method, which can be gold-gold, gold-tin, copper-tin bonding, or other methods. They can also be joined together in other ways, which are not limited here. As shown in FIG. 14 , the second package substrate 60 is provided with a second conductive via 64 that is electrically connected to the electrical connection portion 32 of the top electrode 30 .

In the embodiment of the present invention, when the second packaging substrate 60 is a quartz substrate, it can be a quartz wafer with a thickness of 20-300 μm and completely consistent with the wafer size specifications of the quartz wafer 10 .

In the embodiment shown in FIG. 14 , when the second packaging substrate 60 and the quartz wafer 10 are bonded with metal, a metal bonding layer is also provided at the joint between the second packaging substrate 60 and the quartz wafer 10 72B.

15 is a schematic cross-sectional view of a packaging structure of a quartz resonator according to another exemplary embodiment of the present invention. The structure shown in FIG. 15 differs from the structure shown in FIG. 14 only in the position of the second conductive via hole 64, and other structures will not be described again. In FIG. 14 , the second conductive via 64 is aligned with the via etching area 14 , while in FIG. 15 , the second conductive via 64 is offset from the via etching area 14 . Such misaligned packaging helps to improve the stability of the structure and reduce air-tightness damage caused by through-hole damage caused by stress, mechanical deformation and other issues. At the same time, through-hole dislocation can shield to a certain extent the noise caused by interference such as stress, heat, and electromagnetic signals transmitted through the through-holes.

After step 14, a segmentation operation can be performed to form the final packaged quartz resonator into individual devices.

In one embodiment of the present invention, the size of the finally formed quartz piezoelectric layer is less than 1 mm × 1 mm, and/or the thickness of the resonance region of the quartz piezoelectric layer is less than 40 μm or the fundamental frequency of the quartz resonator is above 40 MHz. This also applies to other embodiments of the invention.

In the present invention, the packaging substrate may be a quartz substrate or a substrate made of other materials, such as silicon, glass, sapphire, etc. No further details will be given in the following embodiments. In the present invention, when the packaging substrate is a quartz substrate, it can be a quartz wafer with a thickness of 20-300 μm and completely consistent with the wafer size specifications of the quartz wafer 10 .

In the present invention, in the case of an all-quartz package, the package cover is made of transparent material. Therefore, frequency modulation can also occur after the packaging is completed, using laser to directly adjust the frequency through the transparent quartz packaging cover to adjust the frequency changes caused by packaging stress. No further details will be given in the following embodiments.

16 to 35 are schematic cross-sectional views of a manufacturing process of a quartz resonator according to yet another exemplary embodiment of the present invention. In this embodiment, the resonant structure of the quartz resonator adopts a double-sided reverse platform structure. Compared with the embodiments shown in Figures 1 to 14, this structure has better structural stability, improves the impact resistance of the chip, and can further Improve the boundary conditions of the resonance area of the chip and reduce the lateral leakage of sound waves, thereby improving the performance of the resonator; in addition, the double-sided anti-elevation structure provides space for the vibration area, which can avoid digging grooves in the package cover and contribute to the thinness of the chip. change.

The following is an example of the manufacturing process of a quartz resonator with reference to Figures 16-35, which includes the following steps:

Step 1: Make mask 20A. As shown in FIG. 16 , a mask 20A is made on one side (eg, the front) of a quartz wafer (eg, 1-8 inches in diameter, 100 μm to 1 mm in thickness) using micro/nano electromechanical system photolithography. Mask 20A is patterned to form mask openings 22 and the area of resonant region 12 is covered. A mask 20A is also provided on the other side (for example, the secondary surface) of the quartz wafer 10, covering the entire the other side.

Step 2: Wet etching. As shown in Figure 17, using the mask 20A as a barrier layer, use an etching liquid (such as an HF etching liquid with a temperature higher than 20°C and a concentration higher than 5%, or a HF/NH4F mixed etching liquid) to etch the quartz wafer. 10 Carry out etching. For example, under the action of high-temperature and high-concentration etching solutions, higher etching rates and steeper crystal plane slopes can be obtained.

Step 3: Further pattern the mask 20A to expose the resonant region, as shown in Figure 18.

Step 4: Wet etching. As shown in Figure 19, using the mask 20A as a barrier layer, use an etching liquid (such as an HF etching liquid with a temperature higher than 20°C and a concentration higher than 5%, or a HF/NH4F mixed etching liquid) to etch the quartz wafer. 10 Carry out etching. In Figure 19, a part of the resonance area of the quartz wafer is etched, and at the same time, the through hole etching area 14 is further etched. In this way, in Figure 19, the depth of the through hole etching area 14 is greater than the etching depth of the resonance area. .

Although not shown, step 4 may also be replaced by dry etching, or wet etching may be combined with dry etching.

Step 5: Remove mask 20A. As shown in FIG. 20 , after the quartz wafer 10 is etched, it can be cleaned and dried, and then the mask 20A can be removed by wet etching.

Step 6: Make the top electrode. As shown in FIG. 21 , the resonator top electrode 30 is fabricated on the quartz wafer 10 by metal sputtering or evaporation. The top electrode 30 is composed of at least one layer of metal, and the metal in direct contact with the surface of the quartz wafer 10 may be chromium, titanium tungsten, molybdenum, gold, silver, etc. Top electrode 30 covers via etched area 14 .

Step 7: Join the first package substrate. As shown in FIG. 22 , align the quartz wafer 10 with the quartz wafer or the first packaging substrate 50 with the first cavity 52 etched in advance, so that the top electrode 30 is exactly located within the first cavity 52 . The first packaging substrate 50 and the quartz wafer 10 can be bonded together using a metal diffusion bonding method, which can be gold-gold, gold-tin, copper-tin bonding, or other methods. They can also be joined together in other ways, which are not limited here. The packaging substrate 50 may also use other packaging materials.

In the embodiment shown in FIG. 22 , when the first packaging substrate 50 and the quartz wafer 10 are bonded with metal, a metal bonding layer is also provided at the joint between the first packaging substrate 50 and the quartz wafer 10 72A.

Step 8: Quartz wafer thinning. As shown in FIG. 23 , the quartz wafer 10 is thinned by grinding and polishing processes.

Step 9: Make mask 20B. As shown in FIG. 24 , a mask 20B is fabricated using micro/nano electromechanical system photolithography on the structure shown in FIG. 23 , and is patterned to form mask openings 22 and expose the resonant region. The material of mask 20B may be consistent with that of mask 20A.

Step 10: Wet etching. As shown in Figure 25, the mask 20B in Figure 24 is used as a barrier layer, and an etching liquid (such as an HF etching liquid with a temperature higher than 20°C and a concentration higher than 5%, or a HF/NH4F mixed etching liquid) is used to The quartz wafer 10 described above is etched. For example, under the action of high-temperature and high-concentration etching solutions, higher etching rates and steeper crystal plane slopes can be obtained. Finally, a double-sided reverse mesa structure is formed, and a through-hole etching area 14' opposite to the through-hole etching area 14 on one side is also formed on the other side of the quartz wafer 10, as shown in Figure 25. In the structure shown in FIG. 25 , the etching depth of the via etching region 14 ′ is consistent with the etching depth of the resonance region on the other side of the quartz wafer 10 . However, the etching depth between the via etching region 14 ′ and the via Part of the quartz piezoelectric layer remains between the hole etching areas 14 .

Although not shown, step 10 may also be replaced by dry etching, or wet etching may be combined with dry etching.

Step 11: Remove mask 20B. As shown in FIG. 26 , the structure shown in FIG. 25 can be cleaned, dried, and then the mask 20B is removed by wet etching.

Step 12: Wafer-level film thickness measurement. The optical method was used to measure the thickness of quartz in the resonance area after grinding. The measurement point must be selected in the area with the top electrode on the other side of the quartz film. As shown in Figure 27, the thickness of the quartz film in the resonance area of each wafer is measured using the method of optically measuring the thickness of the transparent film, and the difference between it and the design value d ₀ is obtained to provide a basis for the next step of adjusting the film thickness of each wafer. .

Step 13: Adjust quartz film thickness. As shown in Figure 28, the quartz plate in the resonance area of the wafer is etched twice using ion beam etching or wet etching. Repeat the operations in Figure 27 and Figure 28 to adjust the thickness of the wafer multiple times to finally obtain a precise thickness. This process can be seen in Figure 50.

Step 14: Make the bottom electrode. As shown in FIG. 29 , the resonator bottom electrode 40 is formed on the quartz wafer 10 by metal sputtering or evaporation. The bottom electrode 40 is composed of at least one layer of metal, and the metal in direct contact with the surface of the quartz wafer 10 should be chromium, titanium tungsten, molybdenum, gold, silver, etc.

Step 15: Make mask 20C. As shown in FIG. 30 , a mask 20C is fabricated using micro/nano electromechanical system photolithography on the structure shown in FIG. 29 , and is patterned to form mask openings 22 , which are exposed. Excluding the via etching area 14' etched in step 10, the mask 20C covers the bottom electrode 40. The material of mask 20E may be consistent with that of mask 20 .

Step 16: For example, dry etching is used to etch the portion of the quartz wafer 10 located at the through-hole etching area 14' to penetrate the through-hole etching area 14', as shown in Figure 31.

Step 17: Remove mask 20C. As shown in FIG. 32 , the structure shown in FIG. 31 can be cleaned, dried, and then the mask 20C is removed by wet etching.

Step 18: Make the electrical connection part 32. As shown in FIG. 33 , the electrical connection portion 32 is formed on the quartz wafer 10 by metal sputtering or evaporation. The electrical connection portion 32 is electrically connected to the metal in the via etching area 14, and is disposed on the same side of the quartz wafer 10 as the bottom electrode 40 and is spaced apart from each other.

Step 19: Frequency measurement and frequency modulation. As shown in FIG. 34 , the measured resonant frequency f of the quartz resonator is smaller than the predetermined resonant frequency f ₀ . For example, the quality of the top electrode 30 can be changed by using a particle beam to improve the quartz resonator. The resonant frequency of the resonator. As can be understood, when the measured resonant frequency meets the set frequency, the frequency modulation step does not need to be performed. This process can be seen in Figure 51.

Step 20: Bond the second package substrate. As shown in FIG. 35 , align the quartz wafer 10 in step 19 with the quartz wafer or the second packaging substrate 60 with the second cavity 62 pre-etched, so that the bottom electrode 40 is exactly located between the second cavity 62 Inside. The second packaging substrate 60 and the quartz wafer 10 can be bonded together using a metal diffusion bonding method, which can be gold-gold, gold-tin, copper-tin bonding, or other methods. They can also be joined together in other ways, which are not limited here. As shown in FIG. 35 , the second packaging substrate 60 is provided with a second conductive via 64 that is electrically connected to the electrical connection portion 32 of the top electrode 30 .

In the embodiment shown in FIG. 35 , when the second packaging substrate 60 and the quartz wafer 10 are bonded with metal, a metal bonding layer is also provided at the joint between the second packaging substrate 60 and the quartz wafer 10 72B.

After step 20, a segmentation operation may be performed to form the final packaged quartz resonator into individual devices.

36-38 are schematic cross-sectional views of a packaging structure of a quartz resonator according to another exemplary embodiment of the present invention. The structure shown in Figures 36-38 is different from the structure shown in Figure 35 only in the position or structure of the second conductive via hole 64, and other structures will not be described again.

In FIGS. 36-38 , the second conductive via 64 is offset from the via 14 . This misaligned packaging helps Improve the stability of the structure and reduce air tightness damage caused by through-hole damage caused by stress, mechanical deformation and other issues. At the same time, through-hole dislocation can shield to a certain extent the noise caused by interference such as stress, heat, and electromagnetic signals transmitted through the through-holes. Compared with the structure shown in Figure 36, the structure shown in Figure 37 improves the through hole manufacturing process and changes the cross-sectional shape of the through hole to a vertical type, thereby improving the air tightness of the through hole. In the structure shown in Figure 38, changing the package bottom plate to a flat plate helps reduce the total thickness of the chip and improves the mechanical stability of the resonance area.

39-49 are schematic cross-sectional views of a manufacturing process of a quartz resonator structure according to yet another exemplary embodiment of the present invention.

Step 1: Make mask 20. As shown in FIG. 39 , a mask 20 is made on one side (for example, the front) of a quartz wafer (for example, 1-8 inches in diameter and 100 μm to 1 mm in thickness) using micro/nano electromechanical system photolithography. Mask 20 is patterned to form a frame mask, and areas of resonant region 12 are exposed. A mask 20 is also provided on the other side of the quartz wafer 10 (for example, the secondary surface). The mask 20 is patterned to form a frame mask, and the resonant region 12 is exposed.

Step 2: Wet etching. As shown in Figure 40, the mask 20 is used as a barrier layer, and an etching liquid (such as an HF etching liquid with a temperature higher than 20°C and a concentration higher than 5%, or a HF/NH4F mixed etching liquid) is used to etch the quartz wafer. 10 Carry out etching. For example, under the action of high-temperature and high-concentration etching solutions, higher etching rates and steeper crystal plane slopes can be obtained.

As shown in FIG. 40 , the portions corresponding to the resonance region on both sides of the quartz wafer 10 are etched.

Step 3: Remove mask 20. As shown in FIG. 41 , after the quartz wafer 10 is etched, the mask 20 can be removed by cleaning, drying, and then wet etching.

Step 4: Make the top electrode. As shown in FIG. 42 , the resonator top electrode 30 is fabricated on the quartz wafer 10 by metal sputtering or evaporation. The top electrode 30 is composed of at least one layer of metal, and the metal in direct contact with the surface of the quartz wafer 10 may be chromium, titanium tungsten, molybdenum, gold, silver, etc.

Step 5: Wafer-level film thickness measurement. The quartz thickness in the resonance area is measured using optical methods. The measurement point must be selected in the area with the top electrode on the other side of the quartz film. As shown in Figure 43, the thickness of the quartz film in the resonance area of each wafer is measured using the method of optically measuring the thickness of the transparent film, and the difference between it and the design value d ₀ is obtained to provide a basis for the next step of adjusting the film thickness of each wafer. .

Step 6: Adjust quartz film thickness. As shown in Figure 44, using ion beam etching or wet etching The quartz plate in the resonance area of the wafer is etched twice. Repeat the operations in Figure 43 and Figure 44 to adjust the thickness of the wafer multiple times to finally obtain a precise thickness. This process can be seen in Figure 50.

Step 7: Make the bottom electrode. As shown in FIG. 45 , the resonator bottom electrode 40 is fabricated on the quartz wafer 10 shown in step 6 by metal sputtering or evaporation. The bottom electrode 40 is composed of at least one layer of metal, and the metal in direct contact with the surface of the quartz wafer 10 should be chromium, titanium tungsten, molybdenum, gold, silver, etc.

Step 8: Join the first package substrate. As shown in Figure 46, the quartz wafer 10 in step 7 and the quartz wafer or the first packaging substrate 50 are bonded together using metal diffusion bonding, which can be gold-gold, gold-tin, copper-tin bonding, etc. . Optionally, the quartz wafer 10 and the quartz wafer or the first packaging substrate 50 can also be joined together in other ways, which are not limited here. The packaging substrate 50 may also use other packaging materials.

As shown in FIG. 46 , the first package substrate 50 is provided with a first conductive via hole 54 in advance, and the first conductive via hole is electrically connected to the corresponding electrode lead-out part.

In an embodiment of the present invention, the first packaging substrate 50 may be a quartz substrate, and its thickness may be 20-200 μm, and may be prepared from a quartz wafer that is exactly the same size and specification as the resonator wafer.

In the embodiment shown in FIG. 46 , when the first packaging substrate 50 and the quartz wafer 10 are bonded with metal, a metal bonding layer is also provided at the joint between the first packaging substrate 50 and the quartz wafer 10 72A.

In a further embodiment, as shown in FIG. 46 , a filling metal layer 74A is provided between the first packaging substrate 50 and the quartz wafer 10 and spaced apart from the outer side of the metal bonding layer 72A. As can be understood, the filling metal layer 74A only needs to be provided on the side where the external connection is provided in the subsequent step 11.

In one embodiment of the present invention, metal bonding layer 72A is spaced apart from fill metal layer 74A by a distance in the range of 2-200 microns.

Step 9: Frequency measurement and frequency modulation. As shown in FIG. 47 , when the measured resonant frequency of the quartz resonator is less than the predetermined resonant frequency, the quality of the top electrode 30 can be changed using, for example, a particle beam to improve the corresponding quartz resonator. the resonant frequency. As can be understood, when the measured resonant frequency meets the set frequency, the frequency modulation step does not need to be performed. This process can be seen in Figure 51.

Step 10: Bond the second package substrate. As shown in FIG. 48 , the structure in step 9 and the second packaging substrate or packaging quartz wafer 60 are bonded together using metal diffusion bonding, which can be gold-gold, gold-tin, copper-tin bonding, etc. Optionally, the quartz wafer 10 and the second packaging substrate or the packaging quartz wafer 60 can also be joined together in other ways, which are not limited here. The second packaging substrate or packaging quartz crystal Circle 60 can also use other packaging materials.

As shown in FIG. 48 , the second package substrate 60 is provided with a second conductive via hole 64 in advance, and the second conductive via hole is electrically connected to the corresponding electrode lead-out part.

In the embodiment shown in FIG. 48 , when the second packaging substrate 60 and the quartz wafer 10 are bonded with metal, a metal bonding layer is also provided at the joint between the second packaging substrate 60 and the quartz wafer 10 72B.

In a further embodiment, as shown in FIG. 48 , a filling metal layer 74B is provided between the second packaging substrate 60 and the quartz wafer 10 and spaced apart from the outer side of the metal bonding layer 72B. As can be understood, the filling metal layer 74B only needs to be provided on the side where the external connection is provided in the subsequent step 11.

In one embodiment of the present invention, metal bonding layer 72B is spaced apart from fill metal layer 74B by a distance in the range of 2-200 microns.

After step 10, a splitting operation may be performed to form a plurality of packaging particles, that is, at least the quartz wafer is cut or split to form a plurality of mechanically separated independent sandwich resonant structures. The sandwich structure includes the first packaging substrate 50, the quartz crystal. Circle 10 or quartz piezoelectric layer and second packaging substrate 60 .

Step 11: Shot electroplating to form the external connection portion 70: As shown in Figure 49, the external connection portion 70 is electrically connected to the second conductive via 64 on the side of the first package substrate 50 away from the top electrode and extends through the sandwich structure. The end surface extends to the side of the second package substrate 60 away from the bottom electrode.

Although not shown, in the embodiments shown in FIGS. 39-49 , the packaging substrate may also be pre-set with a cavity, so that when the packaging substrate faces the corresponding electrode and is bonded to the quartz wafer, the electrode is connected to the quartz wafer. The cavities are opposite.

Based on the embodiments shown in Figures 1 to 49, the present invention also proposes a method for manufacturing a quartz resonator, including the steps:

Provide quartz wafer 10;

Forming a quartz piezoelectric layer on a quartz wafer 10 includes the steps of: using at least micro/nano electromechanical system photolithography technology to form a quartz piezoelectric layer corresponding to a plurality of quartz resonators on the quartz wafer, where the quartz piezoelectric layer is An inverse platform structure including a boss, suitable for disposing a first electrode layer including a first electrode and a second electrode layer including a second electrode on both sides of the quartz piezoelectric layer;

A first packaging substrate and a second packaging substrate are provided, and the first packaging substrate and the second packaging substrate are respectively joined to the bosses on both sides of the quartz piezoelectric layer to form a structure including the first packaging substrate, the quartz piezoelectric layer, and the quartz piezoelectric layer. A sandwich structure of a piezoelectric layer and a second packaging substrate, the first packaging substrate is opposite to the first electrode layer, and the second packaging substrate is opposite to the second electrode layer; and

Dividing: After forming the sandwich structure, at least the sandwich structure is cut or split to form a plurality of mechanically separated sandwich structure particles.

In embodiments of the present invention, micro/nano electromechanical systems (M/NEMS) photolithography technology is used in combination with wet etching/dry etching to: make the size of the particles less than 1 mm × 1 mm; and/or The thickness of the resonant region of the shot particles is less than 40 μm or the fundamental frequency of the resonator formed based on the shot particles is above 40 MHz. Specifically, based on micro/nano electromechanical system photolithography technology, it is possible to obtain fine patterns for subsequent etching that facilitate the formation of particle sizes less than 1 mm × 1 mm, while based on wet etching/dry etching, it is possible to Obtain particles with a size less than 1mm×1mm; based on wet etching/dry etching, it can replace the mechanical mask to obtain a quartz piezoelectric layer thickness less than 40μm.

In the present invention, at least part of the electrical connection through hole or through hole 14 is a tapered hole, or more specifically, the cross section of the electrical connection through hole is a shape that shrinks from the upper and lower sides of the boss to the middle, which is beneficial to forming An electrical connection with good conductivity and stable resistance.

In the present invention, the resonant region refers to the overlapping region of the top electrode, bottom electrode, piezoelectric layer, and cavity or gap in the thickness direction of the piezoelectric layer in the formed quartz resonator. In the present invention, the resonance area of the wafer corresponds to the area in the wafer that needs to be formed as a resonance area of the resonator; the resonance area of the piezoelectric layer corresponds to the area in the piezoelectric layer that needs to be formed as the resonance area of the resonator. . In the present invention, the non-resonant region is a portion outside the resonant region. The non-resonant region of the piezoelectric layer refers to the region outside the resonant region of the piezoelectric layer in the horizontal or lateral direction.

It should be pointed out that in the present invention, each numerical range, except that it is clearly stated that it does not include the endpoint value, can be the endpoint value or the median value of each numerical range, which are all within the protection scope of the present invention. .

As those skilled in the art can understand, the quartz resonator according to the present invention can be used to form a quartz crystal oscillator chip or an electronic device including a quartz resonator. The electronic device here may be an electronic component such as an oscillator, a communication device such as a walkie-talkie or a mobile phone, or a large-scale product using a quartz resonator such as an automobile.

Based on the above, the present invention proposes the following technical solutions:

1. A quartz resonator, including:

in:

2. The resonator according to 1, wherein:

The quartz piezoelectric layer has a single-sided reverse platform structure.

3. The resonator according to 1, wherein:

The quartz piezoelectric layer has a double-sided reverse platform structure.

4. The resonator according to 1, wherein:

Both the first packaging substrate and the second packaging substrate are quartz substrates.

5. The resonator according to 1, wherein:

The size of the quartz piezoelectric layer is less than 1mm×1mm; and/or

The thickness of the resonant region of the quartz piezoelectric layer is less than 40 μm or the fundamental frequency of the resonator is above 40 MHz.

6. The resonator according to any one of 1-5, wherein:

The side of the first packaging substrate and the second packaging substrate facing the boss is a flat surface.

7. The resonator according to any one of 1-5, wherein:

A cavity is provided on a side of the first packaging substrate and/or the second packaging substrate facing the quartz piezoelectric layer, and the projection of the resonance area of the quartz resonator in the thickness direction falls into the cavity.

8. The resonator according to any one of 1-7, wherein:

One of the top electrode and the bottom electrode is a first electrode, and the other is a second electrode, the first electrode is on one side of the quartz piezoelectric layer, and the second electrode is on the other side of the quartz piezoelectric layer;

The quartz piezoelectric layer is provided with an electrical connection through hole in the non-resonant region, and the electrode lead-out portion of the first electrode extends to the other side of the quartz piezoelectric layer through the electrical connection through hole to connect with the third electrode. The two electrodes are located on the same side of the quartz piezoelectric layer.

9. The resonator according to 8, wherein:

The substrate in the first packaging substrate and the second packaging substrate on the other side of the quartz piezoelectric layer is provided with Substrate conductive vias;

The substrate conductive via hole is electrically connected to a portion of the electrode lead-out portion of the first electrode extending to the other side of the quartz piezoelectric layer via the electrical connection via hole.

10. The resonator according to 9, wherein:

The substrate conductive through holes and the electrical connection through holes are staggered in the horizontal direction; or

The substrate conductive via hole and the electrical connection via hole are aligned in the thickness direction.

11. The resonator according to 10, wherein:

The substrate conductive through holes are straight holes, tapered holes, or holes with upper and lower sides narrowing toward the middle.

12. The resonator according to any one of 1-7, wherein:

The first packaging substrate is opposite to the first electrode, and the second packaging substrate is opposite to the second electrode;

The first packaging substrate is provided with a first packaging substrate conductive through hole, and the first packaging substrate conductive through hole is electrically connected to the electrode lead-out portion of the first electrode;

The second packaging substrate is provided with a second packaging substrate conductive through hole, and the second packaging substrate conductive through hole is electrically connected to the electrode lead-out portion of the second electrode;

The resonator further includes an external connection portion, which is electrically connected to the conductive via hole of the first packaging substrate on a side of the first packaging substrate away from the first electrode and extends through the end surface of the sandwich structure of the resonator. and extends to the side of the second packaging substrate away from the second electrode, or the external connection portion is electrically connected to the second packaging substrate conductive via hole on the side of the second packaging substrate away from the second electrode and extends through the The end surface of the sandwich structure of the resonator extends to a side of the first packaging substrate away from the first electrode.

13. The resonator according to 12, wherein:

The first packaging substrate and the second packaging substrate are respectively bonded to the piezoelectric layer packaging part on both sides of the quartz piezoelectric layer based on a metal bonding layer;

The resonator further includes a filling metal layer outside the metal bonding layer and separated from the metal bonding layer. The filling metal layer is connected to the external connection part. Optionally, the metal bonding layer The layer is spaced apart from the fill metal layer by a distance in the range of 2-200 microns.

14. An electronic device, including the quartz resonator according to any one of 1-13.

15. A method of manufacturing a quartz resonator, including the steps:

Provide quartz wafers;

16. The method according to 15, wherein:

The step of forming a quartz piezoelectric layer using a quartz wafer further includes: providing an electrical connection via hole in a non-resonant region of the quartz piezoelectric layer, and the electrode lead-out portion of the first electrode is adapted to extend through the electrical connection via hole. to the other side of the quartz piezoelectric layer so as to be on the same side of the quartz piezoelectric layer as the second electrode;

The method further includes the step of: arranging a substrate conductive via hole in the second packaging substrate, and the substrate conductive via hole and the electrode lead-out portion of the first electrode extend to the quartz piezoelectric layer through the electrical connection via hole. The other side is partially electrically connected.

17. The method according to 15, wherein:

In the step of providing the first packaging substrate and the second packaging substrate, the first packaging substrate is provided with a first packaging substrate conductive through hole, the first packaging substrate conductive through hole is electrically connected to the electrode lead-out portion of the first electrode, and the The two packaging substrates are provided with a second packaging substrate conductive through hole, and the second packaging substrate conductive through hole is electrically connected to the electrode lead-out portion of the second electrode;

The method further includes the step of: providing an external connection part to the sandwich structure shot to form an independent quartz resonator, wherein: the external connection part is electrically conductive with the first packaging substrate on a side of the first packaging substrate away from the first electrode. The through hole is electrically connected and extends through the end surface of the sandwich structure of the resonator to a side of the second packaging substrate away from the second electrode, or the external connection portion is on a side of the second packaging substrate away from the second electrode. The side is electrically connected to the conductive via hole of the second packaging substrate and extends through the end surface of the sandwich structure of the resonator to a side of the first packaging substrate away from the first electrode.

18. The method according to 17, wherein:

The step of providing the external connection part includes: forming the external connection part by metal sputtering or evaporation.

19. The method according to 18, wherein:

The first packaging substrate and the second packaging substrate are respectively joined to the boss in a metal bonding manner on both sides of the quartz piezoelectric layer to form a package including a first packaging substrate, a quartz piezoelectric layer, a third Sandwich structure of two packaging substrates;

Before providing the external connection, the method further includes the steps of: arranging a filling metal layer spaced apart from the bonding layer outside the bonding layer formed by metal bonding; and

In the step of providing the external connection portion, the external connection portion is in contact with the filling metal layer to facilitate planarization of the external connection portion at the end face of the sandwich structure.

Although embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention. The scope of the invention is determined by The appended claims and their equivalents are defined.

Claims

A quartz resonator including:

A bottom electrode, a top electrode and a quartz piezoelectric layer. The quartz piezoelectric layer is an inverted platform structure including a boss;

a packaging structure, including a first packaging substrate, a second packaging substrate and a bonding sealing layer,

in:

The joint sealing layer includes a piezoelectric layer encapsulation part, the piezoelectric layer encapsulation part is a part of the quartz piezoelectric layer, and the piezoelectric layer encapsulation part includes the boss;

The first packaging substrate and the second packaging substrate are respectively joined to the bosses on both sides of the quartz piezoelectric layer to form a sandwich structure including the first packaging substrate, the quartz piezoelectric layer, and the second packaging substrate. .
The resonator of claim 1, wherein:

The quartz piezoelectric layer has a single-sided reverse platform structure.
The resonator of claim 1, wherein:

The quartz piezoelectric layer has a double-sided reverse platform structure.
The resonator of claim 1, wherein:

Both the first packaging substrate and the second packaging substrate are quartz substrates.
The resonator of claim 1, wherein:

The size of the quartz piezoelectric layer is less than 1mm×1mm; and/or

The thickness of the resonant region of the quartz piezoelectric layer is less than 40 μm or the fundamental frequency of the resonator is above 40 MHz.
The resonator according to any one of claims 1-5, wherein:

The side of the first packaging substrate and the second packaging substrate facing the boss is a flat surface.
The resonator according to any one of claims 1-5, wherein:

A cavity is provided on a side of the first packaging substrate and/or the second packaging substrate facing the quartz piezoelectric layer, and the projection of the resonance area of the quartz resonator in the thickness direction falls into the cavity.
The resonator according to any one of claims 1-7, wherein:

One of the top electrode and the bottom electrode is a first electrode, and the other is a second electrode, and the The first electrode is located on one side of the quartz piezoelectric layer, and the second electrode is located on the other side of the quartz piezoelectric layer;

The quartz piezoelectric layer is provided with an electrical connection through hole in the non-resonant region, and the electrode lead-out portion of the first electrode extends to the other side of the quartz piezoelectric layer through the electrical connection through hole to connect with the third electrode. The two electrodes are located on the same side of the quartz piezoelectric layer.
The resonator of claim 8, wherein:

The substrate in the first packaging substrate and the second packaging substrate on the other side of the quartz piezoelectric layer is provided with a substrate conductive via hole;

The substrate conductive via hole is electrically connected to a portion of the electrode lead-out portion of the first electrode extending to the other side of the quartz piezoelectric layer via the electrical connection via hole.
The resonator of claim 9, wherein:

The substrate conductive through holes and the electrical connection through holes are staggered in the horizontal direction; or

The substrate conductive via hole and the electrical connection via hole are aligned in the thickness direction.
The resonator of claim 10, wherein:

The substrate conductive through holes are straight holes, tapered holes, or holes with upper and lower sides narrowing toward the middle.
The resonator according to any one of claims 1-7, wherein:

One of the top electrode and the bottom electrode is a first electrode, and the other is a second electrode, the first electrode is on one side of the quartz piezoelectric layer, and the second electrode is on the other side of the quartz piezoelectric layer;

The first packaging substrate is opposite to the first electrode, and the second packaging substrate is opposite to the second electrode;

The first packaging substrate is provided with a first packaging substrate conductive through hole, and the first packaging substrate conductive through hole is electrically connected to the electrode lead-out portion of the first electrode;

The second packaging substrate is provided with a second packaging substrate conductive through hole, and the second packaging substrate conductive through hole is electrically connected to the electrode lead-out portion of the second electrode;

The resonator further includes an external connection portion, which is electrically connected to the conductive via hole of the first packaging substrate on a side of the first packaging substrate away from the first electrode and extends through the end surface of the sandwich structure of the resonator. and extends to the side of the second packaging substrate away from the second electrode, or the external connection portion is electrically connected to the second packaging substrate conductive via hole on the side of the second packaging substrate away from the second electrode and extends through the The end surface of the sandwich structure of the resonator extends to a side of the first packaging substrate away from the first electrode.
The resonator of claim 12, wherein:

The first packaging substrate and the second packaging substrate are respectively located on both sides of the quartz piezoelectric layer. The side is bonded to the piezoelectric layer encapsulation part based on a metal bonding layer;

The resonator further includes a filling metal layer outside the metal bonding layer and separated from the metal bonding layer. The filling metal layer is connected to the external connection part. Optionally, the metal bonding layer The layer is spaced apart from the fill metal layer by a distance in the range of 2-200 microns.
An electronic device including the quartz resonator according to any one of claims 1-13.
A method for manufacturing a quartz resonator, including the steps:

Provide quartz wafers;

Forming a quartz piezoelectric layer on a quartz wafer includes the steps of: using at least micro/nano electromechanical system photolithography technology to form a quartz piezoelectric layer corresponding to a plurality of quartz resonators on the quartz wafer, and the quartz piezoelectric layer includes: The inverted platform structure of the boss is suitable for disposing a first electrode layer including a first electrode and a second electrode layer including a second electrode on both sides of the quartz piezoelectric layer;

A first packaging substrate and a second packaging substrate are provided, and the first packaging substrate and the second packaging substrate are respectively joined to the boss on both sides of the quartz piezoelectric layer to form a package including the first packaging substrate, quartz A sandwich structure of the piezoelectric layer and the second packaging substrate, the first packaging substrate is opposite to the first electrode layer, and the second packaging substrate is opposite to the second electrode layer; and

Dividing: After forming the sandwich structure, at least the sandwich structure is cut or split to form a plurality of mechanically separated sandwich structure particles.
The method of claim 15, wherein:

One of the top electrode and the bottom electrode is a first electrode, and the other is a second electrode, the first electrode is on one side of the quartz piezoelectric layer, and the second electrode is on the other side of the quartz piezoelectric layer;

The step of forming a quartz piezoelectric layer using a quartz wafer further includes: arranging an electrical connection via hole in a non-resonant region of the quartz piezoelectric layer, and the electrode lead-out portion of the first electrode is adapted to extend through the electrical connection via hole. to the other side of the quartz piezoelectric layer so as to be on the same side of the quartz piezoelectric layer as the second electrode;

The method further includes the step of: arranging a substrate conductive via hole in the second packaging substrate, and the substrate conductive via hole and the electrode lead-out portion of the first electrode extend to the quartz piezoelectric layer through the electrical connection via hole. The other side is partially electrically connected.
The method of claim 15, wherein:

In the step of providing the first packaging substrate and the second packaging substrate, the first packaging substrate is provided with The first packaging substrate conductive via hole is electrically connected to the electrode lead-out portion of the first electrode. The second packaging substrate is provided with a second packaging substrate conductive via hole. The second packaging substrate conductive via hole The hole is electrically connected to the electrode lead-out portion of the second electrode;

The method further includes the step of: providing an external connection part to the sandwich structure shot to form an independent quartz resonator, wherein: the external connection part is electrically conductive with the first packaging substrate on a side of the first packaging substrate away from the first electrode. The through hole is electrically connected and extends through the end surface of the sandwich structure of the resonator to a side of the second packaging substrate away from the second electrode, or the external connection portion is on a side of the second packaging substrate away from the second electrode. The side is electrically connected to the conductive via hole of the second packaging substrate and extends through the end surface of the sandwich structure of the resonator to a side of the first packaging substrate away from the first electrode.
The method of claim 17, wherein:

The step of providing the external connection part includes: forming the external connection part by metal sputtering or evaporation.
The method of claim 18, wherein:

The first packaging substrate and the second packaging substrate are respectively joined to the boss in a metal bonding manner on both sides of the quartz piezoelectric layer to form a package including a first packaging substrate, a quartz piezoelectric layer, a third Sandwich structure of two packaging substrates;

Before providing the external connection, the method further includes the steps of: arranging a filling metal layer spaced apart from the bonding layer outside the bonding layer formed by metal bonding; and

In the step of providing the external connection portion, the external connection portion is in contact with the filling metal layer to facilitate planarization of the external connection portion at the end face of the sandwich structure.