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DE-102024210913-A1 - Microelectromechanical component and microelectromechanical loudspeaker

DE102024210913A1DE 102024210913 A1DE102024210913 A1DE 102024210913A1DE-102024210913-A1

Abstract

The invention relates to a microelectromechanical MEMS component (100) for a microelectromechanical loudspeaker (200), comprising a sound chamber (101), a plurality of moving plates (103) movably arranged in the sound chamber (101), and a drive arrangement (105) with a frame structure (107) and a plurality of piezoelectric drive elements (109) formed on the frame structure (107), wherein the plurality of moving plates (103) extend along a direction of extension (E) and are spaced apart from one another along a direction of movement (D) perpendicular to the direction of extension (E), wherein the drive arrangement (105) is configured by controlling at least one piezoelectric drive element (109) to move the moving plates (103) within the sound chamber (101) along the direction of movement (D) and, by moving the moving plates (103), to generate a sound pressure of a value in the to generate sound chamber (101) in the medium located there. The invention further relates to a microelectromechanical loudspeaker (200).

Inventors

  • Hitesh Gowda Bettaswamy Gowda
  • Timo Schoessler

Assignees

  • Robert Bosch Gesellschaft mit beschränkter Haftung

Dates

Publication Date
20260513
Application Date
20241113

Claims (16)

  1. Microelectromechanical MEMS component (100) for a microelectromechanical loudspeaker (200), comprising a sound chamber (101), a plurality of moving plates (103) movably arranged in the sound chamber (101), and a drive arrangement (105) with a frame structure (107) and a plurality of piezoelectric drive elements (109) formed on the frame structure (107), wherein the plurality of moving plates (103) extend along a direction of extension (E) and are spaced apart from one another along a direction of movement (D) perpendicular to the direction of extension (E) on the frame structure (107), wherein the drive arrangement (105) is configured by controlling at least one piezoelectric drive element (109) to move the moving plates (103) within the sound chamber (101) along the direction of movement (D) and, by moving the moving plates (103), to generate a sound pressure of a certain magnitude in the sound chamber. (101) to produce the medium located there.
  2. MEMS component (100) according to Claim 1 , wherein the frame structure (107) comprises at least one bending beam (111) extending along the direction of extension (E), wherein at least two piezoelectric drive elements (109) are arranged on the bending beam (111), wherein by controlling one of the at least two piezoelectric drive elements (109) a bending of the bending beam (111) about a bending axis (B) oriented perpendicular to the direction of movement (D) and direction of extension (E) and/or a torsion of the bending beam (111) about a longitudinal direction of the bending beam (111) can be effected, and wherein the movement of the motion plates (103) can be effected by bending and/or torsion of the bending beam (111).
  3. MEMS component (100) according to Claim 2 , wherein the at least two piezoelectric drive elements (109) formed on the bending beam (111) extend along a longitudinal axis (L) of the bending beam (111), and wherein the control of the piezoelectric drive elements (109) causes a change in the extension of the piezoelectric drive elements (109) along the longitudinal axis (L) of the bending beam (111) and/or along a transverse axis (Q) of the bending beam (111) perpendicular to the longitudinal axis (L).
  4. MEMS component (100) according to one of the preceding claims, wherein the frame structure (107) comprises a frame base (113), wherein the plurality of motion plates (103) are formed on the frame base (113), wherein the frame base (113) can be moved in a translational movement along the direction of movement (D) by controlling the piezoelectric drive elements (109), and wherein the motion plates (103) formed on the frame base (113) are moved together along the direction of movement (D) by the translational movement of the frame base (113).
  5. MEMS component (100) according to Claim 4 , wherein a plurality of partition walls (117) extending along the direction of extension (E) and spaced apart from each other along the direction of movement (D) are formed on a boundary surface (115) of the sound chamber (101), wherein the partition walls (117) are each arranged between the movement plates (103), and wherein the distances (A1) between the movement plates (103) and the partition walls (117) are varied by the movement of the frame base (113).
  6. MEMS component (100) according to Claim 4 or 5 , wherein the at least one bending beam (111) is fixed to a boundary surface (115) of the sound chamber (101) and is connected to the frame base (113) via a connecting structure (119), and wherein the movement of the frame base (113) along the direction of movement (D) can be effected by bending the bending beam (111) about the bending axis (B).
  7. MEMS component (100) according to one of the preceding Claims 4 until 6 , wherein the movement plates (103) are furthermore fixed to at least one boundary surface (115) of the sound chamber (101), and wherein the translational movement of the frame base (113) along the direction of movement (D) can cause the movement plates (103) to bend about the bending axis (B).
  8. MEMS component (100) according to one of the Claims 4 until 7 , wherein at least two drive element arrangements (121) spaced apart along the longitudinal axis (L) with at least two piezoelectric drive elements (109) each are formed on the bending beams (111), and wherein bending of the respective bending beams (111) about different bending axes (B) can be effected by controlling the piezoelectric drive elements (109) of the drive element arrangements (121).
  9. MEMS component (100) according to Claim 2 or 3 , wherein the frame structure (107) comprises a plurality of bending beams (111), wherein one of the plurality of movement plates (103) is fixed to each bending beam (111), and wherein the movement plate (103) extends along the longitudinal axis (L) of the bending beam (111).
  10. MEMS component (100) according to Claim 9 , wherein bending of the bending beams (111) about the bending axis (B) causes the movement plates (103) fixed to the bending beams (111) to bend about the bending axis (B), and/or wherein torsion of the bending beams (111) about the longitudinal axis (L) of the bending beams (111) causes the movement plates (103) fixed to the bending beams (111) to tilt about the longitudinal axis (L).
  11. MEMS component (100) according to Claim 9 or 10 , wherein the movement plates (103) are made movable relative to each other and distances (A2) between adjacent movement plates (103) are varied by alternately oppositely bending the bending beams (111) about the bending axis (B) and/or by alternately oppositely torsioning the bending beams (111) about the longitudinal axis (L).
  12. MEMS component (100) according to one of the preceding claims, wherein through-openings (123) are formed in at least one boundary surface (115) of the sound chamber (101) and/or the frame base (113).
  13. MEMS component (100) according to Claim 12 , wherein the through openings (123) are formed between the along the direction of movement (D). ten motion plates (103) are arranged and extend along the direction of extension (E).
  14. MEMS component (100) according to one of the preceding claims, wherein at least one piezoelectric layer (125) is formed on each of the piezoelectric drive elements (109) for stress compensation of the piezoelectric drive element (109).
  15. MEMS component (100) according to Claim 14 , wherein the piezoelectric drive elements (109) and the piezoelectric layer (125) are made of the same material and have the same layer thickness, or wherein the piezoelectric drive elements (109) and the piezoelectric layer are made of different materials, and wherein the layer thicknesses are defined depending on the elastic moduli of the respective materials.
  16. Microelectromechanical loudspeaker (200) with a MEMS component (100) according to one of the preceding Claims 1 until 15 .

Description

The present invention relates to a MEMS component and a microelectromechanical loudspeaker with a MEMS component. State of the art MEMS components and microelectromechanical loudspeakers are known from the state of the art. It is an object of the present invention to provide an improved MEMS component and an improved microelectromechanical loudspeaker. The problem is solved by the MEMS component and the loudspeaker of the independent claims. Advantageous embodiments are the subject of the dependent claims. According to one aspect, a microelectromechanical MEMS component for a microelectromechanical loudspeaker is provided, comprising a sound chamber, a plurality of moving plates movably arranged in the sound chamber, and a drive arrangement with at least one frame structure and a plurality of piezoelectric drive elements formed on the frame structure, wherein the plurality of moving plates extend along a direction of extension and are spaced apart from each other along a direction of movement perpendicular to the direction of extension, wherein the drive arrangement is configured by controlling at least one piezoelectric drive element to move the moving plates within the sound chamber along the direction of movement and to generate a sound pressure of a medium located in the sound chamber by moving the moving plates. This allows for the technical advantage of providing an improved MEMS component for use in a microelectromechanical loudspeaker. The sound pressure required for the functionality of the microelectromechanical loudspeaker can be generated within the sound chamber by moving the moving plates relative to each other. By alternately controlling the piezoelectric drive elements according to predefined control frequencies, oscillating movements of the moving plates, and thus sound pressures at the defined control frequencies, can be achieved. The size of the moving plates determines the magnitude of the generable sound pressure. Furthermore, the sound chamber can be reduced to the size of the moving plates, thereby reducing the overall size of the MEMS component. The piezoelectric drive elements enable precise control of the moving plates with a minimal component size. The frame structure provides secure fixation and a robust structure for the moving plates and the entire MEMS component. For the purposes of the application, a MEMS component is a MEMS chip. According to one embodiment, the frame structure comprises at least one bending beam extending along the direction of extension, wherein at least two piezoelectric drive elements are arranged on the bending beam, wherein by controlling one of the at least two piezoelectric drive elements, a bending of the bending beam about a bending axis oriented perpendicular to the direction of movement and extension and/or a torsion of the bending beam about a longitudinal direction of the bending beam can be effected, and wherein the movement of the movement plates can be effected by bending and/or torsion of the bending beam. This allows for the technical advantage that the bending beams, on which the piezoelectric drive elements are mounted, enable targeted control and movement of the moving plates. By controlling the piezoelectric drive elements, the bending beams can be bent along defined bending axes or bent along a longitudinal axis of the bending beams in a synchronized movement. According to one embodiment, the at least two piezoelectric drive elements formed on the bending beam extend along a longitudinal axis of the bending beam, wherein the control of the piezoelectric drive elements causes a change in the extension of the piezoelectric drive elements along the longitudinal axis of the bending beam and/or along a transverse axis of the bending beam perpendicular to the longitudinal axis. This achieves the technical advantage that, through the appropriate placement of the piezoelectric drive elements and the change in their expansion when activated, precise bending or torsion of the bending beams is possible. This precise bending or torsion of the bending beams enables precise control and movement of the moving plates. According to one embodiment, the frame structure comprises a frame base, wherein the plurality of motion plates are formed on the frame base, wherein the frame base can be moved in a translational movement along the direction of movement by controlling the piezoelectric drive elements, and wherein the motion plates formed on the frame base are moved together along the direction of movement by the translational movement of the frame base. This achieves the technical advantage that, through the translational movement of the frame base to which the multiple motion plates are fixed, the motion plates can be moved together along the direction of movement. This enables simple control of the motion plates and a robust frame structure to which the motion plates are fixed. According to one embodiment, a plurality of partition walls extending alo