WO2021134684A1 - 薄膜体声波谐振器 - Google Patents

薄膜体声波谐振器 Download PDF

Info

Publication number
WO2021134684A1
WO2021134684A1 PCT/CN2019/130922 CN2019130922W WO2021134684A1 WO 2021134684 A1 WO2021134684 A1 WO 2021134684A1 CN 2019130922 W CN2019130922 W CN 2019130922W WO 2021134684 A1 WO2021134684 A1 WO 2021134684A1
Authority
WO
WIPO (PCT)
Prior art keywords
substrate assembly
electrode
cavity
reflection structure
substrate
Prior art date
Application number
PCT/CN2019/130922
Other languages
English (en)
French (fr)
Inventor
窦韶旭
吴珂
韩琦
吕丽英
王超
杨帅
庄玉召
张丽蓉
Original Assignee
瑞声声学科技(深圳)有限公司
瑞声科技(新加坡)有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 瑞声声学科技(深圳)有限公司, 瑞声科技(新加坡)有限公司 filed Critical 瑞声声学科技(深圳)有限公司
Priority to PCT/CN2019/130922 priority Critical patent/WO2021134684A1/zh
Publication of WO2021134684A1 publication Critical patent/WO2021134684A1/zh

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/15—Constructional features of resonators consisting of piezoelectric or electrostrictive material
    • H03H9/17—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator

Definitions

  • the present invention relates to the technical field of resonators, in particular to a thin film bulk acoustic wave resonator.
  • FBAR resonator Film Bulk Acoustic Resonator
  • FBAR resonator has the characteristics of small size, small insertion loss, high resonant frequency, etc., and its application in communication systems, especially RF front-ends, is becoming more and more important.
  • the quality factor of the film bulk acoustic wave resonator also known as the Q value, is an important index to measure the performance of a film bulk acoustic wave resonator. How to improve the Q value of the film bulk acoustic wave resonator is a hot topic being studied by those skilled in the art.
  • the purpose of the present invention is to disclose a thin film bulk acoustic resonator.
  • the objective of the present invention is achieved by adopting the following technical solutions to provide a thin film bulk acoustic wave resonator, the thin film bulk acoustic wave resonator comprising:
  • a substrate assembly, an acoustic reflection structure is formed on the surface of the substrate assembly
  • a piezoelectric film the piezoelectric film being disposed on the side of the substrate assembly where the sound reflection structure is formed;
  • the first electrode is arranged between the piezoelectric film and the substrate assembly, and is connected to the piezoelectric film, and the projection part of the first electrode in the first direction covers the An acoustic reflection structure partially located outside the acoustic reflection structure, wherein the first direction is the thickness direction of the substrate assembly;
  • the second electrode is arranged on the side of the piezoelectric film away from the first electrode and connected with the piezoelectric film.
  • the part of the projection of the first electrode in the first direction beyond the sound reflection structure is connected to an electrical signal.
  • the acoustic reflection structure is a cavity with an opening formed on the substrate assembly.
  • the substrate assembly includes a substrate, and the substrate is recessed to form the cavity with the opening.
  • the substrate assembly further includes a support layer disposed above the cavity of the substrate, the projection of the support layer in the first direction covers the cavity, and the first electrode is disposed on the cavity. On the support layer.
  • the substrate assembly includes a substrate and a first support layer provided on the substrate, and the cavity is provided on the first support layer.
  • the substrate assembly further includes a second support layer disposed above the first support layer, the second support layer is provided with a through hole penetrating therethrough, and the through hole is in communication with the cavity And the geometric center is directly opposite, and the projection of the through hole in the first direction completely falls into the cavity;
  • the through hole and the cavity constitute the acoustic reflection structure.
  • the projected area of the through hole in the first direction is smaller than the projected area of the cavity in the first direction.
  • the piezoelectric film is provided with a groove on one side facing the substrate assembly, and the first electrode is accommodated in the groove.
  • the film bulk acoustic resonator provided by the present invention has an acoustic reflection structure formed on the surface of the substrate assembly; the piezoelectric film is arranged on the side of the substrate assembly where the acoustic reflection structure is formed;
  • the electrode is arranged between the piezoelectric film and the substrate assembly, and is connected to the piezoelectric film; the projection of the first electrode in the first direction partially covers the acoustic reflection structure, and is partially located outside the acoustic reflection structure, and the first direction is the substrate The thickness direction of the component; the second electrode is arranged on the side of the piezoelectric film away from the first electrode and connected with the piezoelectric film, thereby reducing the propagation of transverse sound waves to the area outside the sound reflection structure and improving the film bulk acoustic wave resonator The quality factor.
  • FIG. 1 is a schematic diagram of a cross-sectional structure of a thin-film bulk acoustic resonator disclosed in an embodiment of the present invention
  • FIG. 2 is a schematic diagram of a cross-sectional structure of a thin-film bulk acoustic resonator disclosed in another embodiment of the present invention.
  • FIG. 3 is a schematic diagram of a cross-sectional structure of a thin-film bulk acoustic resonator disclosed in another embodiment of the present invention.
  • FIG. 4 is a schematic diagram of a cross-sectional structure of a thin-film bulk acoustic resonator disclosed in another embodiment of the present invention.
  • the present invention provides a thin film bulk acoustic resonator 1, which includes a substrate assembly 10, a piezoelectric film 30, a first electrode 20, and a second electrode 40.
  • An acoustic reflection structure is formed on the surface of the substrate assembly 10; the piezoelectric film 30 is arranged on the side of the substrate assembly 10 where the acoustic reflection structure is formed; the first electrode 20 is arranged between the piezoelectric film 30 and the substrate assembly 10. And connected to the piezoelectric film 30; the projection of the first electrode 20 in the first direction partially covers the acoustic reflection structure, and is partly located outside the acoustic reflection structure, the first direction is the thickness direction of the substrate assembly 10; the second electrode 40 is arranged On the side of the piezoelectric film 30 away from the first electrode 20 and connected to the piezoelectric film 30.
  • the film bulk acoustic resonator 1 is formed by forming an acoustic reflection structure on the surface of a substrate assembly 10; placing a piezoelectric film 30 on the side of the substrate assembly 10 where the acoustic reflection structure is formed; and placing a first electrode 20 on the piezoelectric film 30 and the substrate assembly 10, and connected to the piezoelectric film 30; the projection of the first electrode 20 in the first direction partially covers the acoustic reflection structure, and is partially located outside the acoustic reflection structure, the first direction is the substrate assembly 10
  • the thickness direction of the second electrode 40 is arranged on the side of the piezoelectric film 30 away from the first electrode 20 and connected to the piezoelectric film 30, thereby reducing the propagation of transverse sound waves to the area outside the sound reflection structure and improving the film body The quality factor of an acoustic resonator.
  • connection between the first electrode 20 and the piezoelectric film 30 may be that a groove is provided on the side of the piezoelectric film 30 facing the substrate assembly 10, and the first electrode 20 is accommodated in the groove.
  • the part of the first electrode 20 projected in the first direction beyond the acoustic reflection structure is connected to an electrical signal.
  • the acoustic reflection structure is a cavity 103 with an opening formed on the substrate assembly 10.
  • the cavity 103 is formed in the substrate assembly 10 in a manner that the substrate assembly 10 includes a substrate 101, and the substrate 101 is recessed to form a cavity 103 with an opening, as shown in FIG. 1.
  • the acoustic reflection structure is a cavity 103 with an opening formed on the substrate assembly 10.
  • the cavity 103 is formed in the substrate assembly 10 in a manner that the substrate assembly 10 includes a substrate 101 and a support layer 102, the substrate 101 is recessed to form a cavity 103 with an opening, and the support layer 102 is in the first direction.
  • the projection of is covering the cavity 103, and the first electrode 20 is disposed on the supporting layer 102, as shown in FIG. 2.
  • the acoustic reflection structure is a cavity 103 with an opening formed on the substrate assembly 10.
  • the cavity 103 is formed in the substrate assembly 10 in a manner that the substrate assembly 10 includes a substrate 101 and a first supporting layer 104 disposed on the substrate 101, and the cavity 103 is disposed on the first supporting layer 104, As shown in Figure 3.
  • the acoustic reflection structure includes a cavity 103 formed on the substrate assembly 10 and a through hole 1051 communicating with the cavity 103.
  • the cavity 103 is formed in the substrate assembly 10 in a manner that the substrate assembly 10 includes a substrate 101, a first support layer 104 disposed on the substrate 101, and a second support disposed above the first support layer 104 ⁇ 105 ⁇ Layer 105.
  • the cavity 103 is provided on the first support layer 104
  • the second support layer 105 is provided with a through hole 1051 therethrough
  • the through hole 1051 is in communication with the cavity 103 and the geometric center is directly opposite.
  • the through hole 1051 is on the first side.
  • the upward projection completely falls into the cavity 103, and the through hole 1051 and the cavity 103 form an acoustic reflection structure. That is, the through hole 1051 penetrates the second support layer 105 and communicates with the cavity 1051, as shown in FIG. 4.
  • first support layer 104 and the second support layer 105 may be integrally formed, or may be formed separately and then fixedly connected, which is not limited herein.
  • the projected area of the through hole 1051 in the first direction is smaller than the projected area of the cavity 103 in the first direction.

Abstract

一种薄膜体声波谐振器（1），所述薄膜体声波谐振器（1）包括：衬底组件（10），所述衬底组件（10）的表面形成有声反射结构；压电薄膜（30），所述压电薄膜（30）设置于所述衬底组件（10）上形成有所述声反射结构的一侧；第一电极（20），所述第一电极（20）设置于所述压电薄膜（30）与所述衬底组件（10）之间，并与所述压电薄膜（30）连接，所述第一电极（20）在第一方向上的投影部分覆盖所述声反射结构，且部分位于所述声反射结构外，其中，所述第一方向为衬底组件（10）的厚度方向；及第二电极（40），所述第二电极（40）设置于所述压电薄膜（30）远离所述第一电极（20）一侧，并与所述压电薄膜（30）连接。

Description

薄膜体声波谐振器 技术领域
本发明涉及谐振器技术领域，尤其涉及一种薄膜体声波谐振器。
 背景技术
薄膜体声波谐振器(Film Bulk Acoustic Resonator，FBAR谐振器)具有尺寸小、插入损耗小、谐振频率高等特点，在通信系统,尤其是射频前端中的应用越来越重要。
薄膜体声波谐振器的品质因素，也称Q值是衡量一个薄膜体声波谐振器性能的重要指标，如何提高薄膜体声波谐振器的Q值是本领域技术人员正在研究的一个热门课题。
 技术问题
本发明的目的公开一种薄膜体声波谐振器。
 技术解决方案
本发明的目的采用如下技术方案实现，提供一种薄膜体声波谐振器，所述薄膜体声波谐振器包括：
衬底组件，所述衬底组件的表面形成有声反射结构；
压电薄膜，所述压电薄膜设置于所述衬底组件上形成有所述声反射结构的一侧；
第一电极，所述第一电极设置于所述压电薄膜与所述衬底组件之间，并与所述压电薄膜连接，所述第一电极在第一方向上的投影部分覆盖所述声反射结构，且部分位于所述声反射结构外，其中，所述第一方向为衬底组件的厚度方向；及
第二电极，所述第二电极设置于所述压电薄膜远离所述第一电极一侧，并与所述压电薄膜连接。
优选地，所述第一电极在第一方向上的投影超出所述声反射结构外的部分连接电信号。
优选地，所述声反射结构为形成在所述衬底组件上的具有开口的空腔。
优选地，所述衬底组件包括衬底，所述衬底内凹形成具有所述开口的所述空腔。
优选地，所述衬底组件还包括设置于所述衬底的空腔上方的支撑层，所述支撑层在第一方向上的投影覆盖所述空腔，所述第一电极设置于所述支撑层上。
优选地，所述衬底组件包括衬底和设置于所述衬底上的第一支撑层，所述空腔设置于所述第一支撑层上。
优选地，所述衬底组件还包括设置于所述第一支撑层上方的第二支撑层，所述第二支撑层设有贯通其上的通孔，所述通孔与所述空腔连通且几何中心正对，所述通孔在第一方向上的投影完全落入所述空腔；
所述通孔和所述空腔组成所述声反射结构。
优选地，所述通孔在第一方向上的投影面积小于所述空腔在第一方向上的投影面积。
优选地，所述压电薄膜朝向所述衬底组件的一侧设有凹槽，所述第一电极收容于所述凹槽内。
 有益效果
与现有设计相比，本发明所提供的薄膜体声波谐振器通过在衬底组件的表面形成有声反射结构；将压电薄膜设置于衬底组件上形成有声反射结构的一侧；将第一电极设置于压电薄膜与衬底组件之间，并与压电薄膜连接；第一电极在第一方向上的投影部分覆盖声反射结构，且部分位于声反射结构外，第一方向为衬底组件的厚度方向；将第二电极设置于压电薄膜远离第一电极一侧，并与压电薄膜连接，从而减小了横向声波向声反射结构之外的区域传播，提高薄膜体声波谐振器的品质因素。
 附图说明
图1为本发明一实施例公开的薄膜体声波谐振器的剖面结构示意图；
图2为本发明另一实施例公开的薄膜体声波谐振器剖面结构示意图；
图3为本发明另一实施例公开的薄膜体声波谐振器剖面结构示意图；
图4为本发明另一实施例公开的薄膜体声波谐振器剖面结构示意图。
 本发明的实施方式
下面结合附图和实施方式对本发明作进一步说明。
需要说明，本发明实施例中所有方向性指示（诸如上、下、左、右、前、后……）仅用于解释在某一特定姿态（如附图所示）下各部件之间的相对位置关系、运动情况等，如果该特定姿态发生改变时，则该方向性指示也相应地随之改变。
还需要说明的是，当元件被称为“固定于”或“设置于”另一个元件上时，它可以直接在另一个元件上或者可能同时存在居中元件。当一个元件被称为是“连接”另一个元件，它可以是直接连接另一个元件或者可能同时存在居中元件。
另外，在本发明中涉及“第一”、“第二”等的描述仅用于描述目的，而不能理解为指示或暗示其相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括至少一个该特征。另外，各个实施例之间的技术方案可以相互结合，但是必须是以本领域普通技术人员能够实现为基础，当技术方案的结合出现相互矛盾或无法实现时应当认为这种技术方案的结合不存在，也不在本发明要求的保护范围之内。
请参阅图1-4，本发明提供一种薄膜体声波谐振器1，其包括衬底组件10、压电薄膜30、第一电极20及第二电极40。
其中，衬底组件10的表面形成有声反射结构；压电薄膜30设置于衬底组件10上形成有声反射结构的一侧；第一电极20设置于压电薄膜30与衬底组件10之间，并与压电薄膜30连接；第一电极20在第一方向上的投影部分覆盖声反射结构，且部分位于声反射结构外，第一方向为衬底组件10的厚度方向；第二电极40设置于压电薄膜30远离第一电极20一侧，并与压电薄膜30连接。
该薄膜体声波谐振器1通过在衬底组件10的表面形成有声反射结构；将压电薄膜30设置于衬底组件10上形成有声反射结构的一侧；将第一电极20设置于压电薄膜30与衬底组件10之间，并与压电薄膜30连接；第一电极20在第一方向上的投影部分覆盖声反射结构，且部分位于声反射结构外，第一方向为衬底组件10的厚度方向；将第二电极40设置于压电薄膜30远离第一电极20一侧，并与压电薄膜30连接，从而减小了横向声波向声反射结构之外的区域传播，提高薄膜体声波谐振器的品质因素。
其中，第一电极20与压电薄膜30连接可以是，在压电薄膜30朝向衬底组件10的一侧设有凹槽，第一电极20收容于凹槽内。
较佳地，第一电极20在第一方向上的投影超出声反射结构外的部分连接电信号。
在部分实施例中，声反射结构为形成在衬底组件10上的具有开口的空腔103。其中，空腔103形成于衬底组件10的方式可以是，衬底组件10包括衬底101，衬底101内凹形成具有开口的空腔103，如图1所示。
在部分实施例中，声反射结构为形成在衬底组件10上的具有开口的空腔103。其中，空腔103形成于衬底组件10的方式可以是，衬底组件10包括衬底101和支撑层102，衬底101内凹形成具有开口的空腔103，支撑层102在第一方向上的投影覆盖空腔103，第一电极20设置于支撑层102上，如图2所示。
在部分实施例中，声反射结构为形成在衬底组件10上的具有开口的空腔103。其中，空腔103形成于衬底组件10的方式可以是，衬底组件10包括衬底101和设置于衬底101上的第一支撑层104，空腔103设置于第一支撑层104上，如图3所示。
在部分实施例中，声反射结构包括形成于衬底组件10上的空腔103及与空腔103连通的通孔1051。其中，空腔103形成于衬底组件10的方式可以是，衬底组件10包括衬底101、设置于衬底101上的第一支撑层104及设置于第一支撑层104上方的第二支撑层105。空腔103设置于第一支撑层104上，第二支撑层105上设有贯通其上的通孔1051，且通孔1051与空腔103连通且几何中心正对，通孔1051在第一方向上的投影完全落入空腔103，且通孔1051和空腔103组成声反射结构。即，通孔1051贯穿第二支撑层105并与空腔1051连通，如图4所示。
可以理解，第一支撑层104和第二支撑层105可以是一体成型，也可以是分别成型再固定连接，在此不做限定。
较佳地，通孔1051在第一方向上的投影面积小于空腔103在第一方向上的投影面积。
以上仅是本发明的实施方式，在此应当指出，对于本领域的普通技术人员来说，在不脱离本发明创造构思的前提下，还可以做出改进，但这些均属于本发明的保护范围。

Claims (9)

  1. 一种薄膜体声波谐振器，其特征在于，所述薄膜体声波谐振器包括：
    衬底组件，所述衬底组件的表面形成有声反射结构；
    压电薄膜，所述压电薄膜设置于所述衬底组件上形成有所述声反射结构的一侧；
    第一电极，所述第一电极设置于所述压电薄膜与所述衬底组件之间，并与所述压电薄膜连接，所述第一电极在第一方向上的投影部分覆盖所述声反射结构，且部分位于所述声反射结构外，其中，所述第一方向为衬底组件的厚度方向；及
    第二电极，所述第二电极设置于所述压电薄膜远离所述第一电极一侧，并与所述压电薄膜连接。
  2. 根据权利要求1所述的薄膜体声波谐振器，其特征在于：所述第一电极在第一方向上的投影超出所述声反射结构外的部分连接电信号。
  3. 根据权利要求1所述的薄膜体声波谐振器，其特征在于：所述声反射结构为形成在所述衬底组件上的具有开口的空腔。
  4. 根据权利要求3所述的薄膜体声波谐振器，其特征在于：所述衬底组件包括衬底，所述衬底内凹形成具有所述开口的所述空腔。
  5. 根据权利要求4所述的薄膜体声波谐振器，其特征在于：所述衬底组件还包括设置于所述衬底的空腔上方的支撑层，所述支撑层在第一方向上的投影覆盖所述空腔，所述第一电极设置于所述支撑层上。
  6. 根据权利要求3所述的薄膜体声波谐振器，其特征在于：所述衬底组件包括衬底和设置于所述衬底上的第一支撑层，所述空腔设置于所述第一支撑层上。
  7. 根据权利要求6所述的薄膜体声波谐振器，其特征在于：所述衬底组件还包括设置于所述第一支撑层上方的第二支撑层，所述第二支撑层设有贯通其上的通孔，所述通孔与所述空腔连通且几何中心正对，所述通孔在第一方向上的投影完全落入所述空腔；
    所述通孔和所述空腔组成所述声反射结构。
  8. 根据权利要求7所述的薄膜体声波谐振器，其特征在于：所述通孔在第一方向上的投影面积小于所述空腔在第一方向上的投影面积。
  9. 根据权利要求1所述的薄膜体声波谐振器，其特征在于：所述压电薄膜朝向所述衬底组件的一侧设有凹槽，所述第一电极收容于所述凹槽内。
PCT/CN2019/130922 2019-12-31 2019-12-31 薄膜体声波谐振器 WO2021134684A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2019/130922 WO2021134684A1 (zh) 2019-12-31 2019-12-31 薄膜体声波谐振器

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2019/130922 WO2021134684A1 (zh) 2019-12-31 2019-12-31 薄膜体声波谐振器

Publications (1)

Publication Number Publication Date
WO2021134684A1 true WO2021134684A1 (zh) 2021-07-08

Family

ID=76686193

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/130922 WO2021134684A1 (zh) 2019-12-31 2019-12-31 薄膜体声波谐振器

Country Status (1)

Country Link
WO (1) WO2021134684A1 (zh)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1148290A (zh) * 1995-08-17 1997-04-23 摩托罗拉公司 密封腔上的压电谐振器及其制造方法
US20030227338A1 (en) * 2002-03-29 2003-12-11 Kabushiki Kaisha Toshiba Voltage controlled oscillator
CN207339805U (zh) * 2017-09-27 2018-05-08 佛山市艾佛光通科技有限公司 一种空腔型薄膜体声波谐振器
CN108270414A (zh) * 2017-01-03 2018-07-10 稳懋半导体股份有限公司 具有质量调整结构的体声波共振器的制造方法
CN109309483A (zh) * 2018-10-10 2019-02-05 华南理工大学 一种支撑型薄膜体声波谐振器的制备方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1148290A (zh) * 1995-08-17 1997-04-23 摩托罗拉公司 密封腔上的压电谐振器及其制造方法
US20030227338A1 (en) * 2002-03-29 2003-12-11 Kabushiki Kaisha Toshiba Voltage controlled oscillator
CN108270414A (zh) * 2017-01-03 2018-07-10 稳懋半导体股份有限公司 具有质量调整结构的体声波共振器的制造方法
CN207339805U (zh) * 2017-09-27 2018-05-08 佛山市艾佛光通科技有限公司 一种空腔型薄膜体声波谐振器
CN109309483A (zh) * 2018-10-10 2019-02-05 华南理工大学 一种支撑型薄膜体声波谐振器的制备方法

Similar Documents

Publication Publication Date Title
CN107453729B (zh) 一种基于复合结构的温度补偿薄膜体声波谐振器
TWI667925B (zh) 壓電傳感器
WO2020258334A1 (zh) 谐振器及其制备方法
JPH0218614B2 (zh)
WO2018094963A1 (zh) 一种微硅麦克风及其制造方法
WO2007086180A1 (ja) 超音波探触子
JP2016086308A (ja) 圧電共振器、及び圧電共振器の製造方法
US20220232328A1 (en) Piezoelectric element, piezoelectric device, and manufacturing method of piezoelectric element
CN111490746A (zh) 薄膜体声波谐振器
WO2021134684A1 (zh) 薄膜体声波谐振器
WO2006025138A1 (ja) 圧電型電気音響変換器
US20130223657A1 (en) Electronic device
US11950053B2 (en) MEMS chip
CN104796831B (zh) 一种电容式麦克风及其制造方法
WO2018186280A1 (ja) 圧電音響部品
JP7340910B2 (ja) スピーカおよびスピーカの製造方法
CN210075564U (zh) 复合喇叭膜片
JP2002076823A (ja) 圧電共振子および圧電フィルタ
JP3477270B2 (ja) 超音波送受波器
JP2008022501A (ja) コンデンサマイクロホン及びその製造方法
TWI795701B (zh) 壓電元件、壓電裝置及壓電元件之製造方法
EP1065910B1 (en) Speaker
JPH0213853B2 (zh)
US11805372B2 (en) MEMS chip
JPH09331224A (ja) 振動子の製造方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19958329

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19958329

Country of ref document: EP

Kind code of ref document: A1