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CN-113872548-B - Preparation method of filter, filter and duplexer

CN113872548BCN 113872548 BCN113872548 BCN 113872548BCN-113872548-B

Abstract

The embodiment of the invention discloses a preparation method of a filter, the filter and a duplexer, wherein at least one resonator layer is formed on one side of a first protection substrate and/or one side of a second protection substrate, so that at least two resonator layers arranged along the thickness direction of the filter are formed between the first protection substrate and the second protection substrate, the thicknesses of corresponding setting film layers in the at least two resonator layers are different, and the setting film layer is at least one of a lower electrode layer, an upper electrode layer and a piezoelectric layer. According to the technical scheme, the thickness of the mass load layer can be controlled by controlling the thickness of the set film layers deposited on different resonator layers, and the thickness difference can be calculated by measuring the thickness of the set film layers of different resonator layers, so that the thickness of the mass load layer can be accurately controlled and measured, the accurate frequency modulation of the resonator layers is facilitated, and the frequency of the filter can be accurately controlled.

Inventors

  • WU MING
  • TANG ZHAOYUN
  • YANG QINGHUA

Assignees

  • 苏州汉天下电子有限公司

Dates

Publication Date
20260512
Application Date
20210926

Claims (18)

  1. 1. A method of manufacturing a filter, comprising: Providing a first protective substrate and a second protective substrate; Forming at least one resonator layer on one side of the first protective substrate and/or one side of the second protective substrate; Connecting the first protective substrate and the second protective substrate in the thickness direction of the filter so that at least two resonator layers arranged in the thickness direction of the filter are formed between the first protective substrate and the second protective substrate; the resonator layers comprise lower electrode layers, piezoelectric layers and upper electrode layers which are arranged in a stacked mode, the thicknesses of corresponding setting film layers in at least two resonator layers are different, and the setting film layers are at least one of the lower electrode layers, the upper electrode layers and the piezoelectric layers; The resonator layer comprises a plurality of resonators, the same film layers of the resonators of the same resonator layer have the same thickness, the thicknesses of one of the corresponding film layers of the resonators of different resonator layers are different, and the thickness of the mass load layer can be controlled according to the thickness of at least one of the upper electrode layer, the lower electrode layer and the piezoelectric layer of the different resonator layers, so that accurate frequency trimming can be independently carried out on each resonator layer.
  2. 2. The method for manufacturing a filter according to claim 1, wherein, Before the first protective substrate and the second protective substrate are connected in the thickness direction of the filter so that at least two resonator layers arranged in the thickness direction of the filter are formed between the first protective substrate and the second protective substrate, the method further comprises: Providing an intermediate substrate and forming at least one resonator layer on a first side and/or a second side of the intermediate substrate, wherein the first side and the second side of the intermediate substrate are opposite sides of the intermediate substrate; The connecting the first protective substrate and the second protective substrate in the thickness direction of the filter so as to form at least two resonator layers arranged along the thickness direction of the filter between the first protective substrate and the second protective substrate, includes: bonding the first protection substrate and the middle substrate on the first side of the middle substrate through a bonding structure; and bonding the second protection substrate and the middle substrate on the second side of the middle substrate through a bonding structure.
  3. 3. The method for manufacturing a filter according to claim 2, wherein, The bonding the first protective substrate and the intermediate substrate on the first side of the intermediate substrate through a bonding structure includes: Bonding at least one of the upper electrode layer, the lower electrode layer and the piezoelectric layer of the resonator layer arranged on the first protective substrate, which is close to the surface of the intermediate substrate, and at least one of the upper electrode layer, the lower electrode layer and the piezoelectric layer of the resonator layer arranged on the first side of the intermediate substrate, which is close to the surface of the first protective substrate; the bonding the second protective substrate and the intermediate substrate on the second side of the intermediate substrate through a bonding structure includes: And bonding at least one of the surface of the second protection substrate close to the middle substrate, the upper electrode layer, the lower electrode layer and the piezoelectric layer of the resonator layer arranged on the second protection substrate with at least one of the surface of the middle substrate close to the second protection substrate, the upper electrode layer, the lower electrode layer and the piezoelectric layer of the resonator layer arranged on the second side of the middle substrate.
  4. 4. The method of manufacturing a filter according to claim 1, wherein forming a resonator layer on one side of the first protective substrate and/or one side of the second protective substrate, comprises: forming at least one resonator layer on one side of the second protective substrate; Forming at least two resonator layers layer by layer on one side of the first protective substrate; The connecting the first protective substrate and the second protective substrate in the thickness direction of the filter so as to form at least two resonator layers arranged along the thickness direction of the filter between the first protective substrate and the second protective substrate, includes: And bonding the side of the second protection substrate provided with the resonator layer and the side of the first protection substrate provided with the resonator layer through a bonding structure.
  5. 5. The method of manufacturing a filter according to claim 4, wherein forming at least two resonator layers layer by layer on the side of the first protective substrate comprises forming a first resonator layer on the side of the first protective substrate; Wherein forming a second resonator layer adjacent to the first resonator layer on a side of the first resonator layer remote from the first protective substrate after forming the first resonator layer on the first protective substrate side, comprises: And forming a cap layer on one side of the first resonator layer away from the first protection substrate, and forming a second resonator layer on one side of the cap layer away from the first protection substrate.
  6. 6. The method of manufacturing a filter according to claim 5, wherein the bonding of the side of the second protective substrate on which the resonator layer is provided and the side of the first protective substrate on which the resonator layer is provided by a bonding structure includes: And bonding at least one of the surface of the second protection substrate, which is close to the first protection substrate, the upper electrode layer, the lower electrode layer and the piezoelectric layer of the resonator layer arranged on the second protection substrate, and at least one of the surface of the first protection substrate, which is close to the second protection substrate, the upper electrode layer, the lower electrode layer and the piezoelectric layer of the resonator layer arranged on the first protection substrate, or the cap layer on one side of the resonator layer.
  7. 7. The method of manufacturing a filter according to claim 5, further comprising, before forming a cap layer on a side of the first resonator layer remote from the first protective substrate: forming a sacrificial material on a side of the first resonator layer away from the first protective substrate; After forming a cap layer on a side of the first resonator layer away from the first protective substrate, the method further includes: releasing the sacrificial material.
  8. 8. The method of manufacturing a filter according to claim 1, wherein forming at least one resonator layer on one side of the first protective substrate and/or one side of the second protective substrate, comprises: Forming an acoustic reflection structure on one side of a setting substrate, wherein the setting substrate is the first protection substrate and/or the second protection substrate; Forming a lower electrode layer, a piezoelectric layer and an upper electrode layer in sequence on one side of the setting substrate, on which the acoustic reflection structure is formed; Preferably, a lower electrode layer, a piezoelectric layer and an upper electrode layer are sequentially formed on a side of the setting substrate on which the acoustic reflection structure is formed, including: Forming the lower electrode layer on one side of the setting substrate, on which the acoustic reflection structure is formed, by adopting a primary deposition process and a primary patterning process; forming the piezoelectric layer on one side of the lower electrode layer away from the setting substrate by adopting a primary deposition process and a primary patterning process; and forming the upper electrode layer on one side of the piezoelectric layer away from the setting substrate by adopting a primary deposition process and a primary patterning process.
  9. 9. The method of manufacturing a filter according to claim 1, wherein forming at least one resonator layer on one side of the first protective substrate and/or one side of the second protective substrate comprises forming at least one resonator layer and at least one cap layer on one side of the first protective substrate; forming at least one resonator layer and at least one cap layer on one side of the second protective substrate; The connecting the first protective substrate and the second protective substrate in the thickness direction of the filter so as to form at least two resonator layers arranged along the thickness direction of the filter between the first protective substrate and the second protective substrate, includes: And bonding the side of the first protection substrate provided with the resonator layer and the side of the second protection substrate provided with the resonator layer through a bonding structure.
  10. 10. The method of manufacturing a filter according to claim 9, wherein bonding the side of the first protective substrate on which the resonator layer is provided and the side of the second protective substrate on which the resonator layer is provided by a bonding structure includes: And bonding at least one of the surface of the first protection substrate close to the second protection substrate, the upper electrode layer, the lower electrode layer, the piezoelectric layer and the cover cap layer of the resonator layer arranged on the first protection substrate with at least one of the surface of the second protection substrate close to the first protection substrate, the upper electrode layer, the lower electrode layer, the piezoelectric layer and the cover cap layer of the resonator layer arranged on the second protection substrate.
  11. 11. A kind of filter, which is used to make the filter, characterized by comprising the following steps: A first protective substrate and a second protective substrate in a thickness direction of the filter, and at least two resonator layers provided between the first protective substrate and the second protective substrate in the thickness direction of the filter; The filter further comprises at least one intermediate substrate, wherein the intermediate substrate is arranged between the first protective substrate and the second protective substrate, and the resonator layer is arranged on one side of the intermediate substrate, which is close to the first protective substrate and/or is far away from the first protective substrate; The first protection substrate is in bonding connection with the adjacent intermediate substrate through the bonding structure, and the second protection substrate is in bonding connection with the adjacent intermediate substrate through the bonding structure; The resonator layers comprise lower electrode layers, piezoelectric layers and upper electrode layers which are arranged in a stacked mode, the thicknesses of corresponding setting film layers in at least two resonator layers are different, and the setting film layers are at least one of the lower electrode layers, the upper electrode layers and the piezoelectric layers; The resonator layer comprises a plurality of resonators, the same film layers of the resonators of the same resonator layer have the same thickness, the thicknesses of one of the corresponding film layers of the resonators of different resonator layers are different, and the thickness of the mass load layer can be controlled according to the thickness of at least one of the upper electrode layer, the lower electrode layer and the piezoelectric layer of the different resonator layers, so that accurate frequency trimming can be independently carried out on each resonator layer.
  12. 12. The filter of claim 11, wherein the resonator layer comprises a plurality of resonators including a lower electrode at a lower electrode layer, a piezoelectric unit at the piezoelectric layer, an upper electrode at the upper electrode layer, and the same film layer thickness of each resonator of the same resonator layer is the same.
  13. 13. The filter of claim 11, wherein a cap layer is disposed between at least some adjacent resonator layers, the resonator layers on both sides of the cap layer being connected by a connection structure penetrating the cap layer; preferably, the connection structure is a conductive lead; preferably, the cap layer is formed by deposition.
  14. 14. The filter of claim 13, wherein a plurality of cavities are formed between the cap layer and an upper electrode layer of the resonator layer on a first side, a second side of the cap layer is provided with an acoustic reflecting structure, a lower electrode layer of the resonator layer on the second side at least partially covers the acoustic reflecting structure, and the first side and the second side are opposite sides of the cap layer.
  15. 15. The filter of claim 14, wherein the bonding structure is a first seal ring disposed between adjacent substrates, the substrates being either substrates of the filter or the cap layer, the first seal ring between adjacent substrates forming a seal structure.
  16. 16. A diplexer comprising a transmit filter and a receive filter, the transmit filter and/or the receive filter being the filter of any one of claims 9-15.
  17. 17. The duplexer of claim 16, wherein the transmit filter and the receive filter are bonded in a thickness direction of the duplexer.
  18. 18. The duplexer of claim 17, further comprising a second seal ring between the transmit filter and the receive filter, the transmit filter and the receive filter being bonded by the second seal ring.

Description

Preparation method of filter, filter and duplexer Technical Field The embodiment of the invention relates to the technical field of filter devices, in particular to a preparation method of a filter, the filter and a duplexer. Background With the development of communication technology, the frequency accuracy requirement of the filter is also higher and higher. In the filter, the thickness of the mass loading layer affects the frequency of the filter. In the prior art, a filter generally includes a substrate and a single-layer resonator layer provided on one side of the substrate, the resonator layer including a lower electrode layer, a piezoelectric layer, and an upper electrode layer, which are stacked. The single layer resonator layer generally includes a plurality of resonators including resonators having upper electrodes (located in an upper electrode layer) of different thicknesses, wherein a portion of the upper electrode in the resonator having the upper electrode of a thicker thickness than the upper electrode of the resonator having the upper electrode of a thinner thickness serves as a mass-loaded layer having the upper electrode of a thicker thickness. Because the thicknesses of the upper electrodes of different resonators may be different, the upper electrode layer may be prepared by multiple times of deposition of the upper electrode material, so that the upper electrodes corresponding to different resonators in the upper electrode layer have different thicknesses, or by multiple times of etching after one time of deposition of the upper electrode material, the upper electrodes corresponding to different resonators in the upper electrode layer have different thicknesses. The preparation method is complex in process, and in the filter structure in the prior art obtained through the preparation method, the mass loading layer is connected with the upper electrode layer, so that the actual thickness of the mass loading layer is difficult to accurately measure and control, and the control of the frequency of the filter is difficult. Disclosure of Invention The invention provides a preparation method of a filter, the filter and a duplexer, which are used for accurately controlling and measuring the thickness of a mass load layer and improving the precision of the filter. In a first aspect, an embodiment of the present invention provides a method for manufacturing a filter, including: Providing a first protective substrate and a second protective substrate; forming at least one resonator layer on one side of the first protective substrate and/or one side of the second protective substrate; Connecting the first protective substrate and the second protective substrate in the thickness direction of the filter so that at least two resonator layers arranged in the thickness direction of the filter are formed between the first protective substrate and the second protective substrate; The resonator layer comprises a lower electrode layer, a piezoelectric layer and an upper electrode layer which are arranged in a laminated mode, the thicknesses of corresponding setting film layers in at least two resonator layers are different, and the setting film layers are at least one of the lower electrode layer, the upper electrode layer and the piezoelectric layer. Optionally, before the first protective substrate and the second protective substrate are connected in the thickness direction of the filter so that at least two resonator layers disposed along the thickness direction of the filter are formed between the first protective substrate and the second protective substrate, the method further includes: Providing an intermediate substrate, and forming at least one resonator layer on a first side and/or a second side of the intermediate substrate, wherein the first side and the second side of the intermediate substrate are opposite sides of the intermediate substrate; connecting the first protective substrate and the second protective substrate in the thickness direction of the filter so that at least two resonator layers disposed in the thickness direction of the filter are formed between the first protective substrate and the second protective substrate, comprising: bonding the first protective substrate and the intermediate substrate on the first side of the intermediate substrate through a bonding structure; and bonding the second protection substrate and the middle substrate on the second side of the middle substrate through a bonding structure. Optionally, bonding the first protective substrate to the intermediate substrate at the first side of the intermediate substrate via a bonding structure includes: Bonding at least one of the upper electrode layer, the lower electrode layer and the piezoelectric layer of the resonator layer arranged on the first protective substrate and the surface of the first protective substrate close to the intermediate substrate and the upper electrode layer, the lower electrode laye