阅读说明：本技术 一种晶圆级音叉谐振器 (Wafer-level tuning fork resonator ) 是由 孙晓明 黄祥秒 张威 毛宇 谢凡 晏俊 于 2020-12-31 设计创作，主要内容包括：本发明涉及一种晶圆级音叉谐振器,包括上盖晶圆、谐振片晶圆及底板晶圆,所述谐振片晶圆位于所述上盖晶圆及所述底板晶圆之间,且分别与所述上盖晶圆及所述底板晶圆键合；所述上盖晶圆上开设有多个上盖凹槽及多个上盖电极孔,多个所述上盖凹槽开设于阵列开设于所述上盖晶圆靠近所述谐振片晶圆的一面上,多个所述上盖电极孔阵列开设于所述上盖晶圆上,贯穿所述上盖晶圆,且每个所述上盖凹槽的四角皆存在一个所述上盖电极孔。本发明提供的晶圆级音叉谐振器可减少折取中存在污染和损伤晶片的风险,同时提高生产效率。(The invention relates to a wafer-level tuning fork resonator, which comprises an upper cover wafer, a resonance piece wafer and a bottom plate wafer, wherein the resonance piece wafer is positioned between the upper cover wafer and the bottom plate wafer and is respectively bonded with the upper cover wafer and the bottom plate wafer; the upper cover wafer is provided with a plurality of upper cover grooves and a plurality of upper cover electrode holes, the upper cover grooves are arranged on the upper cover wafer in an array mode and are close to one surface of the resonance piece wafer, the upper cover electrode holes are arranged on the upper cover wafer in a plurality of array modes and penetrate through the upper cover wafer, and each upper cover groove is provided with one upper cover electrode hole in each of four corners. The wafer-level tuning fork resonator provided by the invention can reduce the risks of pollution and chip damage in folding and simultaneously improve the production efficiency.)

1. A wafer-level tuning fork resonator, comprising:

the resonator wafer is positioned between the upper cover wafer and the bottom plate wafer and is respectively bonded with the upper cover wafer and the bottom plate wafer;

the upper cover wafer is provided with a plurality of upper cover grooves and a plurality of upper cover electrode holes, the upper cover grooves are arranged on one surface, close to the resonance piece wafer, of the upper cover wafer in an array mode, the upper cover electrode holes are arranged on the upper cover wafer in an array mode and penetrate through the upper cover wafer, and one upper cover electrode hole is formed in each of four corners of each upper cover groove; an upper cover metal ring is annularly arranged on each of the peripheries of the upper cover grooves, an upper cover electrode extending out of the upper cover electrode is arranged in each upper cover electrode hole, and each upper cover metal ring is in contact with one upper cover electrode and forms electric connection;

a plurality of tuning fork holes and a plurality of resonance electrode holes are formed in the resonance sheet wafer in an array mode, the tuning fork holes and the resonance electrode holes penetrate through the resonance sheet wafer, and one resonance electrode hole is formed in each of four corners of each tuning fork hole; a tuning fork sheet is arranged in the tuning fork hole, resonance metal rings are arranged around the tuning fork sheet, the resonance metal rings are positioned on two surfaces of the bonded resonance sheet wafer, the upper cover wafer and the bottom plate wafer, resonance electrodes extending out of the resonance electrode holes are arranged in the resonance electrode holes, and each resonance metal ring is in contact with one resonance electrode and is electrically connected with the resonance electrode; a tuning fork electrode is attached to the tuning fork sheet, extends towards the resonant metal ring and is in contact with the resonant metal ring to form electric connection;

a plurality of baseplate grooves and a plurality of baseplate electrode holes are formed in the baseplate wafer in an array mode, the baseplate grooves are formed in one surface, close to the resonant chip wafer, of the baseplate wafer, baseplate metal rings are arranged on the periphery of the baseplate grooves, the baseplate electrode holes penetrate through the baseplate wafer, baseplate electrodes extending out of the baseplate electrode holes are arranged in the baseplate electrode holes, one baseplate electrode hole is formed in each of the four corners of each baseplate groove, and each baseplate metal ring is in contact with one baseplate electrode and is electrically connected with the baseplate electrode;

and a plurality of welding sheets are further arranged on one surface of the bottom plate wafer, which is far away from the resonance sheet wafer, in an array manner, and the plurality of welding sheets are respectively contacted with the plurality of bottom plate electrodes to form electric connection.

2. The wafer-level tuning fork resonator of claim 1, wherein:

and pins extend from the upper cover electrode, the resonance electrode and the bottom plate electrode towards the upper cover metal ring, the resonance metal ring and the bottom plate metal ring respectively so as to be in contact with and form electric connection with the outer rings of the upper cover metal ring, the resonance metal ring and the bottom plate metal ring respectively.

3. The wafer-level tuning fork resonator of claim 1, wherein:

the upper cover electrode, the upper cover metal ring, the resonance electrode, the resonance metal ring, the bottom plate electrode and the bottom plate metal ring are all of a double-layer structure.

4. The wafer-level tuning fork resonator of claim 1, wherein:

the bottom plate electrodes of which the arrays form the inner ring and the outer ring are in contact with one or two welding sheets and form electric connection.

5. The wafer-level tuning fork resonator of claim 4, wherein:

among the plurality of the bottom plate electrodes arranged in an array, the bottom plate electrode positioned at the outer ring is electrically connected with one welding sheet, and the bottom plate electrode positioned at the inner ring is simultaneously electrically connected with two welding sheets.

6. The wafer-level tuning fork resonator of claim 1, wherein:

the bottom plate electrodes of the inner ring and the outer ring which are formed in the array are in contact with two or four welding sheets and are electrically connected.

7. The wafer-level tuning fork resonator of claim 6, wherein:

among the plurality of the bottom plate electrodes arranged in an array, the bottom plate electrode positioned at the outer ring is electrically connected with the two welding sheets, and the bottom plate electrode positioned at the inner ring is simultaneously electrically connected with the four welding sheets.

8. The wafer-level tuning fork resonator of claim 1, wherein:

one end of the tuning fork piece extends towards the inner wall of the tuning fork hole to form connection with the inner wall of the tuning fork hole.

9. The wafer-scale tuning fork resonator of claim 8, wherein:

the tuning fork electrodes are of two-layer structures and are respectively attached to one surfaces, close to the upper cover wafer and the bottom plate wafer, of the tuning forks.

10. The wafer-scale tuning fork resonator of claim 9, wherein:

the two layers of the tuning fork electrodes extend towards the inner wall direction of the tuning fork hole.

Technical Field

The invention relates to the field of electronic component packaging, in particular to a wafer-level tuning fork resonator.

Background

The quartz tuning fork crystal resonator mainly comprises a quartz resonator chip, a base, a shell, silver colloid and the like. Along with the development of novel electronic products, especially mobile terminals, intelligent wearing and other requirements, the requirements on the overall dimension and the volume of the quartz tuning fork crystal resonator are smaller and smaller. The traditional wafer processing cutting, grinding and polishing process can not meet the requirements on the aspects of the processing precision, the characteristic size of the appearance or the appearance, the frequency range and the like of the wafer.

Quartz tuning fork crystal resonators are surface mounted on the market, although wafers have begun to be processed using photolithographic processes. However, each resonator plate is folded one by one, and there is also a risk of contamination and damage to the wafer during folding. Resulting in reduced product performance, low yield and insufficient process capability of the production line. The resonator assembly is a one-die stand-alone assembly. A conductive adhesive is dispensed in a separate susceptor, the wafer is bonded and fixed in the susceptor by the conductive adhesive, and then the frequency is adjusted separately and seam welding is performed in parallel one by one. The whole process is processed one by one, and the efficiency is extremely low.

Therefore, a new crystal resonator is needed, which uses a wafer-level packaging technology, and the wafer, the base, and the cover wafer all use a large wafer method, and are packaged into an entire resonator by bonding between the wafers, and then diced into individual resonator units.

Disclosure of Invention

In view of this, the invention provides a wafer-level tuning fork resonator, which solves the problems that the conventional resonator needs to be packaged piece by piece, the risk of polluting and damaging the chip exists, and the efficiency is extremely low.

In order to achieve the above object, an embodiment of the present invention provides a wafer-level tuning fork resonator, including: the resonator wafer is positioned between the upper cover wafer and the bottom plate wafer and is respectively bonded with the upper cover wafer and the bottom plate wafer; the upper cover wafer is provided with a plurality of upper cover grooves and a plurality of upper cover electrode holes, the upper cover grooves are arranged on one surface, close to the resonance piece wafer, of the upper cover wafer in an array mode, the upper cover electrode holes are arranged on the upper cover wafer in an array mode and penetrate through the upper cover wafer, and one upper cover electrode hole is formed in each of four corners of each upper cover groove; an upper cover metal ring is annularly arranged on each of the peripheries of the upper cover grooves, an upper cover electrode extending out of the upper cover electrode is arranged in each upper cover electrode hole, and each upper cover metal ring is in contact with one upper cover electrode and forms electric connection; a plurality of tuning fork holes and a plurality of resonance electrode holes are formed in the resonance sheet wafer in an array mode, the tuning fork holes and the resonance electrode holes penetrate through the resonance sheet wafer, and one resonance electrode hole is formed in each of four corners of each tuning fork hole; a tuning fork sheet is arranged in the tuning fork hole, resonance metal rings are arranged around the tuning fork sheet, the resonance metal rings are positioned on two surfaces of the bonded resonance sheet wafer, the upper cover wafer and the bottom plate wafer, resonance electrodes extending out of the resonance electrode holes are arranged in the resonance electrode holes, and each resonance metal ring is in contact with one resonance electrode and is electrically connected with the resonance electrode; a tuning fork electrode is attached to the tuning fork sheet, extends towards the resonant metal ring and is in contact with the resonant metal ring to form electric connection; a plurality of baseplate grooves and a plurality of baseplate electrode holes are formed in the baseplate wafer in an array mode, the baseplate grooves are formed in one surface, close to the resonant chip wafer, of the baseplate wafer, baseplate metal rings are arranged on the periphery of the baseplate grooves, the baseplate electrode holes penetrate through the baseplate wafer, baseplate electrodes extending out of the baseplate electrode holes are arranged in the baseplate electrode holes, one baseplate electrode hole is formed in each of the four corners of each baseplate groove, and each baseplate metal ring is in contact with one baseplate electrode and is electrically connected with the baseplate electrode; and a plurality of welding sheets are further arranged on one surface of the bottom plate wafer, which is far away from the resonance sheet wafer, in an array manner, and the plurality of welding sheets are respectively contacted with the plurality of bottom plate electrodes to form electric connection.

Further, the upper cover electrode, the resonance electrode and the bottom plate electrode respectively extend out of pins towards the upper cover metal ring, the resonance metal ring and the bottom plate metal ring to respectively contact with the outer rings of the upper cover metal ring, the resonance metal ring and the bottom plate metal ring and form electric connection.

Further, the upper cover electrode, the upper cover metal ring, the resonance electrode, the resonance metal ring, the bottom plate electrode and the bottom plate metal ring are all of a double-layer structure.

Further, the bottom plate electrodes of the inner ring and the outer ring formed by the array are in contact with one or two welding sheets and are electrically connected.

Furthermore, among the plurality of the bottom plate electrodes arranged in an array, the bottom plate electrode positioned at the outer ring is electrically connected with one welding sheet, and the bottom plate electrode positioned at the inner ring is simultaneously electrically connected with two welding sheets.

Further, the bottom plate electrodes of the inner ring and the outer ring formed by the array are in contact with two or four welding sheets and are electrically connected.

Furthermore, among the plurality of the bottom plate electrodes arranged in an array, the bottom plate electrode positioned at the outer ring is electrically connected with the two welding sheets, and the bottom plate electrode positioned at the inner ring is simultaneously electrically connected with the four welding sheets.

Further, one end of the tuning fork piece extends toward the inner wall of the tuning fork hole to form a connection with the inner wall of the tuning fork hole.

Further, the tuning fork electrodes are of two-layer structures and are respectively attached to one surface, close to the upper cover wafer and the bottom plate wafer, of the tuning fork.

Further, the two layers of the tuning fork electrodes extend towards the inner wall of the tuning fork hole.

Compared with the prior art, the wafer-level tuning fork resonator provided by the invention has the following beneficial effects:

the upper cover wafer, the resonance wafer and the bottom plate wafer are sequentially bonded, an upper cover metal ring and an upper cover electrode are respectively arranged on the upper cover wafer, a tuning fork sheet, a resonance metal ring and a resonance electrode are arranged on the resonance wafer, a bottom plate metal ring, a bottom plate electrode and a welding sheet are arranged on the bottom plate wafer, the upper cover metal ring and the upper cover electrode are respectively in contact with the resonance metal ring and the resonance electrode to form electric connection after bonding, the bottom plate metal ring and the bottom plate electrode are respectively in contact with the resonance metal ring and the resonance electrode to form electric connection, and therefore after bonding, the wafer-level resonator can be directly split to form a plurality of tuning fork resonators. Thereby reducing the risk of contamination and damage to the wafer during the folding process and improving the production efficiency.

Drawings

Fig. 1 is a schematic structural diagram of a wafer-level tuning fork resonator according to a first embodiment of the present invention;

FIG. 2 is a schematic structural diagram of the lid wafer of FIG. 1;

FIG. 3 is an enlarged view of a portion of FIG. 2 at A;

fig. 4 is a schematic structural diagram of a resonator plate wafer in fig. 1;

FIG. 5 is a partial enlarged view of the portion B in FIG. 4;

FIG. 6 is a schematic structural diagram of the base wafer of FIG. 1;

FIG. 7 is a schematic plan view of a base wafer in accordance with an embodiment;

FIG. 8 is a schematic plan view of a base wafer in accordance with another embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1-8, a wafer-level tuning fork resonator 10 according to a first embodiment of the present invention includes a top cover wafer 20, a resonator plate wafer 30, and a bottom plate wafer 40, wherein the resonator plate wafer 30 is located between the top cover wafer 20 and the bottom plate wafer 40, and two opposite surfaces of the resonator plate wafer 30 are respectively bonded to the top cover wafer 20 and the bottom plate wafer 40, and the top cover wafer 20, the resonator plate wafer 30, and the bottom plate wafer 40 have the same shape and size, so that a closed cavity space is provided after the top cover wafer 20 and the bottom plate wafer 40 are respectively bonded to the resonator plate wafer 30.

Specifically, a plurality of upper cover grooves 21 and a plurality of upper cover electrode holes 22 are formed in the upper cover wafer 20, the plurality of upper cover grooves 21 are arranged on one surface of the upper cover wafer 20 close to the resonator plate wafer 30 in an array manner, the plurality of upper cover electrode holes 22 are arranged on the upper cover wafer 20 in an array manner, the upper cover wafer 20 penetrates through the plurality of upper cover electrode holes, and one upper cover electrode hole 22 is formed in each of four corners of each upper cover groove 21. Each upper cover electrode hole 22 is internally provided with an upper cover electrode 23, each upper cover groove 21 is internally provided with an upper cover metal ring 24 in a ring manner, the upper cover metal rings 24 are annularly arranged around the upper cover grooves 21, the upper cover electrodes 23 are attached to the inner wall of the upper cover electrode holes 22, and the upper cover electrode holes 22 extend towards the upper cover wafer 20 and close to the resonator plate wafer 30. Wherein each of the cap metal rings 24 is in contact with one of the cap electrodes 23 to form an electrical connection.

It is understood that there is one cap electrode hole 22 at each of the four corners of each cap recess 21, i.e. there is one cap electrode 23 at each of the four corners of each cap metal ring 24, and each cap metal ring 24 contacts and is electrically connected to one of the four cap electrodes 23.

It is understood that the top-cap electrodes 22 are made of conductive metal, and each top-cap electrode 23 is electrically connected to only one top-cap metal ring 24, i.e. when one top-cap electrode 23 is electrically connected to one top-cap metal ring 24, the top-cap electrode 23 is no longer electrically connected to other top-cap metal rings 24.

It is understood that, after the top cover electrodes 23 extend out of the top cover electrode holes 22 toward the resonator plate wafer 30, pins extend out toward the top cover metal ring 24, so as to contact and form electrical connection with the outer ring of the top cover metal ring 24 through the pins.

The resonator plate wafer 30 has a plurality of tuning fork holes 31 and a plurality of resonator electrode holes 32, and the array of tuning fork holes 31 is formed on the resonator plate wafer 30 and penetrates through the resonator plate wafer 30. The array of the plurality of resonant electrode holes 32 is formed on the resonator plate wafer 30, and penetrates through the resonator plate wafer 30, and one resonant electrode hole 32 is formed at each of four corners of each tuning fork hole 31. The resonant electrode hole 32 is provided therein with a resonant electrode 33, and the resonant electrode 33 is attached to an inner wall of the resonant electrode hole 32 and extends out of the resonant electrode hole 32 toward the resonant wafer 30 and the top and bottom wafers 20 and 40, respectively. The tuning fork hole 31 is provided with a tuning fork piece 35, and a resonant metal ring 34 is disposed around the tuning fork piece 35, wherein the resonant metal ring 34 is disposed on two sides of the resonant piece wafer 30 bonded to the top cover wafer 20 and the bottom plate wafer 40, respectively. Each of the resonance metal rings 34 is in contact with and electrically connected to one of the resonance electrodes 33 at its four corners. A tuning fork electrode 36 is attached to the tuning fork piece 35, and the tuning fork electrode 36 extends toward the resonating metal ring 34 and contacts the resonating metal ring 34 to form an electrical connection.

It is understood that, after extending out of the resonant electrode hole 32, a plurality of resonant electrodes 33 also extend out of the pins toward the direction close to the resonant metal ring 34, so as to contact and form an electrical connection with the outer ring of the upper cover metal ring 24 through the pins.

The bottom plate wafer 40 has a plurality of bottom plate grooves 41 and a plurality of bottom plate electrode holes 42, the bottom plate grooves 41 are arranged in an array on one side of the bottom plate wafer 40 close to the resonator plate wafer 30, and a bottom plate metal ring 44 is arranged around the bottom plate grooves. The bottom plate electrode holes 42 are arranged on the bottom plate wafer 40 in an array, penetrate through the bottom plate wafer 40, and a bottom plate electrode hole 42 is arranged at each of four corners of each bottom plate groove 41. A bottom plate electrode 43 is arranged in the bottom plate electrode hole 42, the bottom plate electrode 43 is attached in the bottom plate electrode hole 42 and extends out of the bottom plate electrode hole 42, and each bottom plate metal ring 44 is in contact with and electrically connected with one bottom plate electrode 43.

It is understood that, after extending out of the bottom plate electrode hole 42, a plurality of bottom plate electrodes 43 also extend out of the pins toward the direction close to the bottom plate metal ring 44, so as to contact and form an electrical connection with the outer ring of the bottom plate metal ring 44 through the pins.

The bottom plate wafer 40 is further provided with a plurality of soldering pads 45 on a surface thereof away from the resonator plate wafer 30, and the plurality of soldering pads 45 are arranged on the bottom plate wafer 40 in an array and are in contact with and electrically connected to the bottom plate electrodes 43 extending out of the bottom plate electrode holes 42.

It can be understood that after the resonator plate wafer 30 is bonded to the top cover wafer 20 and the bottom plate wafer 40, the plurality of tuning fork holes 31 are respectively overlapped with the plurality of top cover grooves 21 and the plurality of bottom plate grooves 41, and the plurality of resonator electrode holes 22 are respectively overlapped with the plurality of top cover electrode holes 22 and the plurality of bottom plate electrode holes 42. That is, after the resonator plate wafer 30 is bonded to the top cover wafer 20 and the bottom plate wafer 40, the resonator metal ring 34 is in contact with and electrically connected to the top cover metal ring 24 and the bottom plate metal ring 44, the resonator electrode 33 is in contact with and electrically connected to the top cover electrode 23 and the bottom plate electrode 43, and the top cover groove 21 and the bottom plate groove 41 cooperate to form a cavity for accommodating the tuning fork 35. The bonded upper cover wafer 20, the resonator plate wafer 30 and the bottom plate wafer 40 are equally divided by taking the tuning fork plate as a unit, so that a plurality of tuning fork resonators are formed.

Furthermore, the top cover electrode 23, the top cover metal ring 24, the resonant electrode 33, the resonant metal ring 34, the bottom plate electrode 43 and the bottom plate metal ring 44 are all of a double-layer structure to increase the thickness and enhance the stability of the electrical conduction after the top cover wafer 20 and the bottom plate wafer 40 are respectively bonded with the resonant chip wafer.

Further, the plurality of bottom plate electrodes 43 are arrayed to form an outer ring and an inner ring, wherein the outer ring is the outermost bottom plate electrode 43, the inner ring is the other bottom plate electrodes except the outer ring, and neither the bottom plate electrode 43 of the inner ring nor the bottom plate electrode 43 of the outer ring includes the bottom plate electrodes 43 located at four corners behind the array.

In one embodiment, the backplane electrodes 43 forming the outer and inner loops are in contact with and form an electrical connection with one or both of the weld tabs.

In one embodiment, the bottom plate electrodes 43 forming the outer and inner rings are formed such that the bottom plate electrode 43 at the outer ring is in contact with and electrically connected to one of the solder tabs 45, and the bottom plate electrode 43 at the inner ring is in contact with and electrically connected to both of the solder tabs 45, as shown in fig. 7.

The backplane electrode 43, which in one embodiment forms the outer and inner loops, is in contact with and makes electrical connection with two or four of the weld tabs.

In one embodiment, in the bottom plate electrodes 43 forming the outer and inner rings, the bottom plate electrode 43 located at the outer ring is in contact with and electrically connected to two weld tabs 45, while the bottom plate electrode 43 located at the inner ring is in contact with and electrically connected to four weld tabs 45 at the same time, as shown in fig. 8.

Further, one end of the tuning fork piece 35 extends toward the inner wall of the tuning fork hole 31 to form a connection with the inner wall of the tuning fork hole.

Further, the tuning fork electrode 36 has a two-layer structure, and is respectively attached to the tuning fork piece 35 on a side close to the top cover wafer 20 and the bottom plate wafer 40.

Further, the two layers of the tuning fork electrodes 36 extend towards the inner wall of the tuning fork hole.

The working principle of the invention is as follows: after the upper cover wafer 20, the resonance wafer 30 and the bottom plate wafer 40 are bonded, preheating and heating are carried out to 280 ℃ under the vacuum condition, then load pressurization and AuSn brazing filler metal fusion are carried out, the frequency of each resonance unit is finely adjusted by adopting a laser mode, and then a dicing saw or a laser cutting machine is used for splitting, so that a plurality of tuning fork resonators are formed.

Compared with the prior art, the wafer-level tuning fork resonator provided by the invention has the following beneficial effects:

the upper cover wafer, the resonance wafer and the bottom plate wafer are sequentially bonded, an upper cover metal ring and an upper cover electrode are respectively arranged on the upper cover wafer, a tuning fork sheet, a resonance metal ring and a resonance electrode are arranged on the resonance wafer, a bottom plate metal ring, a bottom plate electrode and a welding sheet are arranged on the bottom plate wafer, the upper cover metal ring and the upper cover electrode are respectively in contact with the resonance metal ring and the resonance electrode to form electric connection after bonding, the bottom plate metal ring and the bottom plate electrode are respectively in contact with the resonance metal ring and the resonance electrode to form electric connection, and therefore after bonding, the wafer-level resonator can be directly split to form a plurality of tuning fork resonators. Thereby reducing the risk of contamination and damage to the wafer during the folding process and improving the production efficiency.

The above-described embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the present invention.