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CN-121985726-A - Filter wafer, filter, radio frequency module and terminal equipment

CN121985726ACN 121985726 ACN121985726 ACN 121985726ACN-121985726-A

Abstract

The application provides a filter wafer, a filter, a radio frequency module and terminal equipment, wherein the filter wafer comprises a first piezoelectric substrate, a second piezoelectric substrate, a first interdigital transducer and a second interdigital transducer, the second piezoelectric substrate and the first piezoelectric substrate are oppositely arranged along the thickness direction of the filter wafer, the first interdigital transducer is arranged on one side of the first piezoelectric substrate, which is away from the second piezoelectric substrate, and the second interdigital transducer is arranged on one side of the second piezoelectric substrate, which is away from the first piezoelectric substrate, wherein the first piezoelectric substrate is provided with a first optical axis P1, the second piezoelectric substrate is provided with a second optical axis P2, and an included angle between the second optical axis P2 and the first optical axis P1 is theta, and theta is equal to 0 degrees. The wafer of the filter is beneficial to miniaturization design of the filter, thereby being beneficial to miniaturization of terminal equipment.

Inventors

  • PENG BIAO
  • DOU SHAOXU

Assignees

  • 北京荣耀终端有限公司

Dates

Publication Date
20260505
Application Date
20260402

Claims (14)

  1. 1. The filter wafer is characterized by comprising a first piezoelectric substrate, a second piezoelectric substrate, a first interdigital transducer and a second interdigital transducer, wherein the second piezoelectric substrate and the first piezoelectric substrate are oppositely arranged along the thickness direction of the filter wafer, the first interdigital transducer is arranged on one side of the first piezoelectric substrate, which is away from the second piezoelectric substrate, and the second interdigital transducer is arranged on one side of the second piezoelectric substrate, which is away from the first piezoelectric substrate; the first piezoelectric substrate has a first optical axis P1, the second piezoelectric substrate has a second optical axis P2, and an included angle between the second optical axis P2 and the first optical axis P1 is θ, θ+.0°.
  2. 2. The filter wafer of claim 1, wherein the first piezoelectric substrate is formed by cutting a first initial wafer along γ1° Y-X, specifically, the first piezoelectric substrate is formed by rotating the first initial wafer by γ1° around an electrical axis X of the first initial wafer, and cutting the first initial wafer with a plane perpendicular to the Y axis as a cutting plane; The second piezoelectric substrate is formed by cutting a second initial wafer along gamma 2 degrees Y-X, specifically, the second piezoelectric substrate is formed by rotating the second initial wafer by gamma 2 degrees around an electric axis X of the second initial wafer, and cutting the second initial wafer by taking a plane perpendicular to the Y axis as a cutting plane; the first optical axis P1 and the second optical axis P2 face the same side of the thickness direction of the filter wafer, and γ2+noteγ1.
  3. 3. The filter wafer of claim 2, wherein θ = 30 ° to 130 °, or θ = 210 ° to 320 °.
  4. 4. The filter wafer according to claim 1, wherein the first optical axis P1 and the second optical axis P2 are oriented toward the same side of the thickness direction of the filter wafer, the first piezoelectric substrate has a first tangential axis Y1', the first tangential axis Y1' is not parallel to the first optical axis P1, the second piezoelectric substrate has a second tangential axis Y2', the second tangential axis Y2' is not parallel to the second optical axis P2, and an angle between the second tangential axis Y2 'and the first tangential axis Y1' is α1, α1+.0°.
  5. 5. The filter wafer of claim 4, wherein α1 = 20 ° -100 °, or α1 = 140 ° -220 °, or α1 = 260 ° -340 °.
  6. 6. The filter wafer of claim 4, wherein the first piezoelectric substrate includes a first surface and a second surface disposed opposite to each other in a thickness direction of the first piezoelectric substrate, the first optical axis P1 is inclined from the second surface toward the first surface, the second piezoelectric substrate includes a third surface and a fourth surface disposed opposite to each other in the thickness direction of the second piezoelectric substrate, the second optical axis P2 is inclined from the fourth surface toward the third surface, and the third surface is oriented toward the second surface.
  7. 7. The filter wafer according to claim 1, wherein the first optical axis P1 and the second optical axis P2 are directed to both sides of the thickness direction of the filter wafer, respectively.
  8. 8. The filter wafer of claim 7, wherein the first piezoelectric substrate has a first tangential axis Y1', the second piezoelectric substrate has a second tangential axis Y2', and an angle between the second tangential axis Y2 'and the first tangential axis Y1' is α2, α2=0° to 40 °, or α2=80° to 160 °, or α2=200° to 280 °, or α2=320° to 360 °.
  9. 9. The filter wafer of claim 7, wherein the first piezoelectric substrate includes a first surface and a second surface disposed opposite to each other in a thickness direction of the first piezoelectric substrate, the first optical axis P1 is inclined from the second surface toward the first surface, the second piezoelectric substrate includes a third surface and a fourth surface disposed opposite to each other in the thickness direction of the second piezoelectric substrate, the second optical axis P2 is inclined from the fourth surface toward the third surface, and the fourth surface is oriented toward the second surface.
  10. 10. The filter wafer according to any of claims 1 to 9, wherein an angle between the extension direction of the first interdigital transducer and the extension direction of the second interdigital transducer is β, β+note0 °.
  11. 11. The filter wafer of claim 10, wherein β = 5 ° to 90 °.
  12. 12. A filter comprising a circuit board and the filter wafer of any of claims 1 to 11, wherein the first interdigital transducer and the second interdigital transducer are both electrically connected to the circuit board.
  13. 13. A radio frequency module comprising a substrate and the filter of claim 12, the filter being mounted to the substrate.
  14. 14. A terminal device comprising a housing and the radio frequency module of claim 13, the radio frequency module being mounted to the housing.

Description

Filter wafer, filter, radio frequency module and terminal equipment Technical Field The present application relates to the field of filters, and in particular, to a filter wafer, a filter, a radio frequency module, and a terminal device. Background At present, miniaturization trend of terminal equipment is more and more obvious, a circuit board in the terminal equipment is also miniaturized gradually, and the ratio of a filter to a circuit board of a radio frequency module of the terminal equipment is generally larger, so that miniaturization of a filter such as a Surface Acoustic Wave (SAW) WAVE FILTER filter becomes a research and development important work of various filter manufacturers. Disclosure of Invention The application aims to provide a filter wafer, a filter, a radio frequency module and terminal equipment, and the filter wafer is used for facilitating the miniaturization design of the filter, so that the miniaturization of the terminal equipment is facilitated. The embodiment of the application provides a filter wafer, which comprises a first piezoelectric substrate, a second piezoelectric substrate, a first interdigital transducer and a second interdigital transducer, wherein the second piezoelectric substrate and the first piezoelectric substrate are oppositely arranged along the thickness direction of the filter wafer; the first piezoelectric substrate has a first optical axis P1, the second piezoelectric substrate has a second optical axis P2, and an included angle between the second optical axis P2 and the first optical axis P1 is θ, θ is not equal to 0 °. In the filter wafer provided by the embodiment of the application, the first piezoelectric substrate and the second piezoelectric substrate are arranged oppositely along the thickness direction of the filter wafer so as to achieve the double-sided filtering effect, thereby realizing miniaturization design, being beneficial to reducing the occupied space of the filter in the radio frequency module on the substrate and further being beneficial to realizing miniaturization of terminal equipment. In addition, through setting up the contained angle θ between the second optical axis of first piezoelectricity substrate and the first optical axis of second piezoelectricity substrate not equal 0, namely through setting up the optical axis of first piezoelectricity substrate and the optical axis of second piezoelectricity substrate inconsistent, can promote the isolation between first filter unit and the second filter unit that second piezoelectricity substrate and second interdigital transducer constitute of first piezoelectricity substrate and first interdigital transducer to do benefit to the performance of promoting the filter, and do not need additionally to increase the isolation layer, further do benefit to the miniaturized design of filter. In one possible embodiment, the first piezoelectric substrate is formed by dicing the first initial wafer along γ1° Y-X, that is, the first piezoelectric substrate is formed by rotating the first initial wafer by γ1° about the electrical axis X of the first initial wafer, and dicing the first initial wafer with a plane perpendicular to the Y axis as a dicing plane. The second piezoelectric substrate is formed by cutting the second initial wafer along the gamma 2 degrees Y-X, namely, the second piezoelectric substrate is formed by rotating the second initial wafer by gamma 2 degrees around the electric axis X of the second initial wafer and cutting the second initial wafer by taking a plane perpendicular to the Y axis as a cutting plane. The first optical axis P1 and the second optical axis P2 face the same side of the thickness direction of the filter wafer, and γ2 is not equal to γ1, so that an included angle θ is not equal to 0 degree between the first optical axis of the first piezoelectric substrate and the second optical axis of the second piezoelectric substrate is achieved, and isolation between a first filter unit formed by the first piezoelectric substrate and the first interdigital transducer and a second filter unit formed by the second piezoelectric substrate and the second interdigital transducer is improved. In one possible embodiment, θ=30° to 130 °, or θ=210° to 320 °. In one possible implementation, the first optical axis P1 and the second optical axis P2 face the same side of the thickness direction of the filter wafer, the first piezoelectric substrate has a first tangential axis Y1', the first tangential axis Y1' is not parallel to the first optical axis P1, the second piezoelectric substrate has a second tangential axis Y2', the second tangential axis Y2' is not parallel to the second optical axis P2, and an included angle between the second tangential axis Y2 'and the first tangential axis Y1' is α1, α1+.0°, so as to realize an included angle θ+.0° between the first optical axis P1 of the first piezoelectric substrate and the second optical axis P2 of the second piezoelectric subs