TW201830982A - Electro-acoustic transducer - Google Patents

Abstract

A electro-acoustic transducer includes a base, at least one vibration portion and at least one partition structure. The vibration portion is connected to the base and includes a piezoelectric transducer layer. The partition structure is connected to the vibration portion to partition the vibration portion into a first area and a second area. The piezoelectric transducer layer is adapted to transduce one of a first acoustic wave and a first electrical signal into another one of the first acoustic wave and the first electrical signal at the first area. The piezoelectric transducer layer is adapted to transduce one of a second acoustic wave and a second electrical signal into another one of the second acoustic wave and the second electrical signal at the second area. A frequency of the first acoustic wave is higher than a frequency of the second acoustic wave.

Description

Electroacoustic converter

This invention relates to an electroacoustic transducer, and more particularly to a piezoelectric electroacoustic transducer.

The electro-acoustic transducer can be applied to a sound input device such as a microphone, and can be applied to a sound output device such as a speaker. In the case of a piezoelectric electroacoustic transducer, an electric signal is applied to the upper and lower electrodes of the piezoelectric material to deform the piezoelectric material by the piezoelectric effect, and the corresponding diaphragm is vibrated to generate a corresponding acoustic wave. Conversely, an acoustic wave may be applied to the vibrating membrane to vibrate the corresponding piezoelectric material to generate a corresponding electrical signal using the piezoelectric effect of the piezoelectric material.

Consumer electronics, such as smart phones, notebook computers, tablet PCs, etc., are usually equipped with microphones and speakers, and consumers are pursuing high-quality and multi-functional consumption. Under the trend of sexual electronic products, in order to improve the market competitiveness of products, the industry hopes to apply advanced technology to develop and manufacture electroacoustic transducers for microphones and speakers. Therefore, how to effectively improve the electro-acoustic conversion quality of the sound input/output device and make it perform well in low-frequency input/output and high-frequency input/output is an important issue in the field of electroacoustic converter research and development.

The present invention provides an electroacoustic transducer that performs well in both low frequency input/output and high frequency input/output.

The electroacoustic transducer of the present invention includes a base, at least one vibrating portion, and at least one partition structure. The vibrating portion is coupled to the base and includes a piezoelectric conversion layer. The partition structure is coupled to the vibrating portion to partition the vibrating portion into a first region and a second region. The piezoelectric conversion layer is adapted to convert one of the first acoustic wave and the first electrical signal into one of the first acoustic wave and the first electrical signal in the first region. The piezoelectric conversion layer is adapted to convert one of the second acoustic wave and the second electrical signal into the other of the second acoustic wave and the second electrical signal in the second region. The frequency of the first sound wave is higher than the frequency of the second sound wave.

In an embodiment of the invention, the resonant frequency of the first region is higher than the resonant frequency of the second region.

In an embodiment of the invention, the piezoelectric conversion layer is adapted to receive the first electrical signal in the first region and deform in the first region to drive the vibrating portion to vibrate in the first region to generate the first acoustic wave, and the voltage is generated. The electrical conversion layer is adapted to receive the second electrical signal in the second region and deform in the second region to drive the vibrating portion to vibrate in the second region to generate the second acoustic wave.

In an embodiment of the invention, the vibrating portion is adapted to receive the first acoustic wave and vibrate in the first region to drive the piezoelectric conversion layer to deform in the first region to generate the first electrical signal, and the vibrating portion is adapted to receive The second sound wave vibrates in the second region to drive the piezoelectric conversion layer to deform in the second region to generate a second electrical signal.

In an embodiment of the invention, the partition structure is a frame, the frame surrounds the first area, and the second area surrounds the frame.

In an embodiment of the invention, the piezoelectric conversion layer includes an upper electrode layer, a piezoelectric material layer and a lower electrode layer, and the piezoelectric material layer is disposed between the upper electrode layer and the lower electrode layer.

In an embodiment of the invention, the upper electrode layer includes at least one first electrode and at least one second electrode, the first electrode is disposed in the first region and is adapted to receive or output the first electrical signal, and the second electrode The second area is adapted to receive or output a second electrical signal.

In an embodiment of the invention, the pedestal has at least one electrical contact, the first electrode is connected to the electrical contact by a line, the line passes through the second area, and a width of the second electrode Greater than 1.5 times a width of the line on the second area.

In an embodiment of the invention, the base has an opening, and the vibrating portion is located in the opening and has a plurality of elastic arms connected to the base by the respective elastic arms.

In an embodiment of the invention, the number of the at least one vibrating portion is plural, and the number of the at least one partitioning structure is plural, and the partitioning structures are respectively connected to the vibrating portions.

In an embodiment of the invention, the thickness of the partition structure along a vibration direction of the vibrating portion is smaller than the thickness of the susceptor along the vibration direction.

Based on the above, in the electroacoustic transducer of the present invention, the vibrating portion is partitioned into the first region and the second region having different resonance frequencies by the partition structure. According to this, the vibrating portion can perform the conversion between the first sound wave of the high frequency and the corresponding first electric signal by the first region, and can further perform the second sound wave of the low frequency and the corresponding second telecommunication by the second region. Conversion between numbers. Thus, the electroacoustic transducer of the present invention can perform well in both low frequency input/output and high frequency input/output.

The above described features and advantages of the invention will be apparent from the following description.

1 is a plan view of an electroacoustic transducer according to an embodiment of the present invention. Figure 2 is a cross-sectional view of the electroacoustic transducer of Figure 1 taken along line A-A. Referring to FIG. 1 and FIG. 2, the electroacoustic transducer 100 of the present embodiment is, for example, an electroacoustic transducer manufactured by a microelectromechanical process, and can be applied to a sound input device such as a microphone, a speaker, and the like. Device or ultrasonic transducer. The electroacoustic transducer 100 includes a base 110, a vibrating portion 120, and a partition structure 130. The vibrating portion 120 is coupled to the susceptor 110 and includes a piezoelectric conversion layer 122. The partition structure 130 is connected to the vibrating portion 120 to partition the vibrating portion 120 into a first region 120a and a second region 120b having different resonance frequencies. In the present embodiment, the partition structure 130 is, for example, a frame, the frame surrounds the first region 120a, and the second region 120b surrounds the frame.

A resonant frequency of the first region 120a is, for example, the same as or similar to a frequency of a first acoustic wave, and a resonant frequency of the second region 120b is, for example, the same as or similar to a frequency of a second acoustic wave, and the first region 120a The resonant frequency is higher than the resonant frequency of the second region 120b. That is, the frequency of the first sound wave is higher than the frequency of the second sound wave.

3A and 3B illustrate the high frequency output and the low frequency output of the electroacoustic transducer of FIG. 2, respectively. With the above configuration, the piezoelectric conversion layer 122 can convert one of the first acoustic wave and the first electrical signal into one of the first acoustic wave and the first electrical signal in the first region 120a as shown in FIG. 3A. One (FIG. 3A illustrates that the piezoelectric conversion layer 122 converts the first electrical signal into the first acoustic wave W1 in the first region 120a). In addition, the piezoelectric conversion layer 122 can convert one of the second acoustic wave and the second electrical signal into the other of the second acoustic wave and the second electrical signal in the second region 120b as shown in FIG. 3B (FIG. 3B). The piezoelectric conversion layer 122 is shown to convert the second electrical signal into the second acoustic wave W2 in the second region 120b. That is, the vibrating portion 120 can perform the conversion between the high frequency first sound wave and the corresponding first electric signal by using the first region 120a as shown in FIG. 3A, and can also borrow the second region as shown in FIG. 3B. 120b performs a conversion between the second acoustic wave of the low frequency and the corresponding second electrical signal. Therefore, the electroacoustic transducer 100 of the present embodiment can perform well in both low frequency input/output and high frequency input/output.

In detail, the piezoelectric conversion layer 122 is adapted to receive the first electrical signal in the first region 120a and deform in the first region 120a to drive the vibration portion 120 to vibrate in the first region 120a to generate the first acoustic wave, and the piezoelectric conversion The layer 122 is adapted to receive the second electrical signal in the second region 120b and deform in the second region 120b to drive the vibrating portion 120 to vibrate in the second region 120b to generate a second acoustic wave. In addition, the vibrating portion 120 is adapted to receive the first acoustic wave and vibrate in the first region 120a to drive the piezoelectric conversion layer 122 to deform in the first region 120a to generate a first electrical signal, and the vibrating portion 120 is adapted to receive the second acoustic wave. The second region 120b vibrates to drive the piezoelectric conversion layer 122 to deform in the second region 120b to generate a second electrical signal.

For example, the electroacoustic transducer 100 can be applied to a sound input device such as a microphone, so that the sound input device has good low frequency input and high frequency input performance, and the electroacoustic transducer 100 can be applied to a speaker, etc. The sound output device enables the sound output device to have good low frequency output and high frequency output performance. In addition, the electroacoustic transducer 100 can also be applied to an acoustic wave ranging device, so that the acoustic wave ranging device can perform low-range sound waves (corresponding to the second sound wave) to perform ranging, and can emit high-frequency sound waves (corresponding to the first The sound wave is subjected to ranging to obtain a ranging signal with a higher resolution (corresponding to the first electrical signal described above), and the ranging accuracy is improved by alternately measuring the low frequency sound wave and the high frequency sound wave.

In more detail, the partition structure 130 functions to provide a higher structural strength at the boundary between the first region 120a and the second region 120b, so that the first region 120a becomes a vibration structure independent of the second region 120b, thereby A region 120a is capable of independently vibrating at a higher frequency (as shown in Figure 3A). Further, when the second region 120b vibrates at a lower frequency, the first region 120a connected to the center of the second region 120b is displaced, for example, as the second region 120b vibrates at a low frequency as shown in FIG. 3B.

The first sound wave and the second sound wave may be sound waves having a suitable higher frequency and a lower frequency, respectively, and the present invention does not limit the actual frequency value. That is, the present invention does not limit the resonant frequency of the first region 120a and the resonant frequency of the second region 120b, which may vary depending on design requirements. For example, the resonant frequency of the first region 120a and the resonant frequency of the second region 120b can be changed by changing the size of the first region 120a and the size of the second region 120b.

The specific structure of the vibrating portion 120 and the piezoelectric conversion layer 122 of the present embodiment will be described in detail below. Referring to FIG. 2, the vibrating portion 120 of the present embodiment includes a carrier layer 124. The piezoelectric conversion layer 122 is disposed on one side of the carrier layer 124 (on the upper side of the carrier layer 124 in FIG. 2), and the partition structure 130 is disposed on the carrier. The other side of layer 124 (the underside of carrier layer 124 in Figure 2). In other embodiments, the piezoelectric conversion layer 122 and the separation structure 130 may be disposed on the same side of the carrier layer 124, which is not limited by the present invention. The carrier layer 124 is, for example, a device layer in the form of a silicon on insulator (SOI) or other suitable non-piezoelectric material, but the invention is not limited thereto. The susceptor 110 is also, for example, a handle layer in the form of a silicon on insulator (SOI) or other suitable material, which is not limited by the present invention.

The piezoelectric conversion layer 122 includes an upper electrode layer 122a, a piezoelectric material layer 122b, and a lower electrode layer 122c, and the piezoelectric material layer 122b is disposed between the upper electrode layer 122a and the lower electrode layer 122c. In the present embodiment, the piezoelectric material layer 122b is also covered, for example, on the susceptor 110. The material of the upper electrode layer 122a is, for example, but not limited to, gold (Au), and the material of the lower electrode layer 122c is, for example, but not limited to, platinum (Pt). In terms of sound output, the upper electrode layer 122a and the lower electrode layer 122c are adapted to receive a voltage signal (such as the first electrical signal or the second electrical signal) to generate a voltage difference, thereby driving the piezoelectricity therebetween The material layer 122b is deformed to further vibrate the vibrating portion 120 to output an acoustic wave (such as the first acoustic wave or the second acoustic wave). In terms of sound input, when an acoustic wave (such as the first acoustic wave or the second acoustic wave) is input to the vibrating portion 120 to vibrate the vibrating portion 120 and drive the piezoelectric material layer 122b to be deformed, the upper electrode layer 122a and the lower electrode The piezoelectric material layer 122b between the layers 122c generates a voltage difference to cause the upper electrode layer 122a and the lower electrode layer 122c to generate an electrical signal (such as the first electrical signal or the second electrical signal).

Further, the upper electrode layer 122a includes a first electrode 122a1 and a plurality of second electrodes 122a2 (shown as four) as shown in FIG. 1 and FIG. 2, and the first electrode 122a1 is disposed in the first region 120a and configured to Receiving or outputting the first electrical signal, and the second electrode 122a2 is disposed in the second region 120b and configured to receive or output the second electrical signal. In addition, the susceptor 110 has an electrical contact 112, a plurality of electrical contacts 114 and an electrical contact 116. The first electrode 122a1 is connected to the electrical contact 112 by a line 126a, and each second The electrode 122a2 is connected to the electrical contact 114 by a line 126b, and the lower electrode layer 122c is connected to the electrical contact 116, so that the first electrode 122a1, the second electrode 122a2 and the lower electrode layer 122c can respectively pass through the electrical contact. 112. The electrical contact 114 and the electrical contact 116 receive or output a telecommunication signal.

The present invention does not limit the number of vibrating portions and partition structures in the electroacoustic transducer, and is exemplified as follows. 4 is a top plan view of an electroacoustic transducer according to another embodiment of the present invention. The difference between the electroacoustic transducer 100' of FIG. 4 and the electroacoustic transducer 100 of FIG. 1 is that the number of the vibrating portions 120 of the electroacoustic transducer 100' is plural (illustrated as four) and arranged in an array. The number of the partition structures 130 is correspondingly plural (illustrated as four), and the partition structures 130 are respectively connected to the vibrating portions 120. Accordingly, the sound input/output performance of the electroacoustic transducer 100' can be improved by the increase in the number of the vibrating portions 120.

Fig. 5 is a plan view showing a partial structure of an electroacoustic transducer according to another embodiment of the present invention. In order to make the drawings clearer, FIG. 5 does not show the electrodes and electrical contacts of the electroacoustic transducer 200. In the electroacoustic transducer 200 shown in FIG. 5, the susceptor 210, the vibrating portion 220, the first region 220a, the second region 220b, and the partition structure 230 are arranged and operated in a manner similar to the susceptor 110 and the vibrating portion 120 of FIG. The arrangement and mode of operation of the first region 120a, the second region 120b, and the partition structure 130 are not described herein again. The electroacoustic transducer 200 is different from the electroacoustic transducer 100 in that the vibrating portion 220, the first region 220a, the second region 220b, and the partition structure 230 are not the vibrating portion 120, the first region 120a, and the second region of FIG. 120b. The partition structure 130 is rectangular, and the vibrating portion 220, the first region 220a, the second region 220b, and the partition structure 230 are circular. In other embodiments, the vibrating portion, the first region, the second region, and the partition structure may be other suitable shapes, which are not limited by the present invention.

Fig. 6 is a plan view showing a partial structure of an electroacoustic transducer according to another embodiment of the present invention. Figure 7 is a cross-sectional view of the electroacoustic transducer of Figure 6 taken along line B-B. In the electroacoustic transducer 300 shown in FIG. 6 and FIG. 7, the susceptor 310, the electrical contact 312, the electrical contact 314, the electrical contact 316, the vibrating portion 320, the first region 320a, and the second region are provided. 320b, the piezoelectric conversion layer 322, the upper electrode layer 322a, the first electrode 322a1, the second electrode 322a2, the piezoelectric material layer 322b, the lower electrode layer 322c, the carrier layer 324, the line 326a, and the partition structure 330 are arranged and operated in a similar manner. The susceptor 110, the electrical contact 112, the electrical contact 114, the electrical contact 116, the vibrating portion 120, the first region 120a, the second region 120b, the piezoelectric conversion layer 122, and the upper electrode of FIGS. 1 and 2 The arrangement and mode of operation of the layer 122a, the first electrode 122a1, the second electrode 122a2, the piezoelectric material layer 122b, the lower electrode layer 122c, the carrier layer 124, the line 126a, and the partition structure 130 will not be described herein.

The difference between the electroacoustic transducer 300 and the electroacoustic transducer 100 is that the base 310 has an opening 310a, and the vibrating portion 320 is located in the opening 310a and has a plurality of elastic arms 328 (shown as four), and each The elastic arm 328 is coupled to the base 310. Each of the elastic arms 328 is part of the second region 320b, and the second electrodes 322a2 are respectively located on the elastic arms 328. Further, the line 326a extends through the elastic arm 328 of the second region 320b, and the width of the second electrode 322a2 is greater than 1.5 times the width of the line 326a on the elastic arm 328 of the second region 320b to avoid an excessively large area of the line 326a. Produces an unexpected piezoelectric effect.

Hereinafter, the manufacturing process will be described by taking the electroacoustic transducer 300 shown in FIGS. 6 and 7 as an example. 8A to 8D are manufacturing flowcharts of the electroacoustic transducer of Fig. 7. First, a lower electrode layer 322c and a piezoelectric material layer 322b are formed on a substrate 50 as shown in FIG. 8A. Next, the piezoelectric material layer 322b is patterned as shown in FIG. 8B to expose the local lower electrode layer 322c. Then, a metal layer is deposited to the piezoelectric material layer 322b and the exposed lower electrode layer 322c, and the metal layer is patterned to form the first electrode 322a1, the second electrode 322a2, and the electrical contact 316 as shown in FIG. 8C. (Electrical contacts 312, 314 shown in Fig. 6 are also formed at this time). The piezoelectric material layer 322b, the lower electrode layer 322c, and a portion of the substrate 50 are patterned as shown in FIG. 8D to form the elastic arms 328. Finally, the substrate 50 is patterned from the underside of the overall structure to form the electroacoustic transducer 300 shown in FIG.

In addition, the thickness of the partition structure can be changed according to the design requirements, as described below. 9A and 9B illustrate a partial manufacturing process of an electroacoustic transducer according to another embodiment of the present invention. After proceeding to the manufacturing process shown in FIG. 8D, the substrate 50 may be first patterned (illustrated as patterning the block R1) as shown in FIG. 9A, and then the substrate is shown in FIG. 9B. The material 50 is patterned in a second stage (illustrated as patterning the block R2) such that the thickness of the partition structure 330' of the formed electroacoustic transducer 300' along the vibration direction D of the vibrating portion 320 is less than the base. The thickness of the seat 310 along the vibration direction D.

As described above, in the electroacoustic transducer of the present invention, the vibrating portion is partitioned into the first region and the second region having different resonance frequencies by the partition structure. According to this, the vibrating portion can perform the conversion between the first sound wave of the high frequency and the corresponding first electric signal by the first region, and can further perform the second sound wave of the low frequency and the corresponding second telecommunication by the second region. Conversion between numbers. Thus, the electroacoustic transducer of the present invention can perform well in both low frequency input/output and high frequency input/output.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

50‧‧‧Substrate

100, 100', 200, 300, 300'‧‧‧ electroacoustic converters

110, 210, 310‧‧‧ base

112, 114, 116, 312, 314, 316‧‧‧ electrical contacts

120, 220, 320‧‧‧Vibration Department

120a, 220a, 320a‧‧‧ first area

120b, 220b, 320b‧‧‧ second area

122, 322‧‧‧ Piezoelectric conversion layer

122a, 322a‧‧‧ upper electrode layer

122a1, 322a1‧‧‧ first electrode

122a2, 322a2‧‧‧ second electrode

122b, 322b‧‧‧ piezoelectric material layer

122c, 322c‧‧‧ lower electrode layer

124, 324‧‧‧ carrying layer

126a, 126b, 326a‧‧‧ lines

130, 230, 330, 330' ‧ ‧ separation structure

310a‧‧‧ openings

328‧‧‧Bounce arm

D‧‧‧Vibration direction

R1, R2‧‧‧ blocks

1 is a plan view of an electroacoustic transducer according to an embodiment of the present invention. Figure 2 is a cross-sectional view of the electroacoustic transducer of Figure 1 taken along line A-A. 3A and 3B illustrate the high frequency output and the low frequency output of the electroacoustic transducer of FIG. 2, respectively. 4 is a top plan view of an electroacoustic transducer according to another embodiment of the present invention. Fig. 5 is a plan view showing a partial structure of an electroacoustic transducer according to another embodiment of the present invention. Fig. 6 is a plan view showing a partial structure of an electroacoustic transducer according to another embodiment of the present invention. Figure 7 is a cross-sectional view of the electroacoustic transducer of Figure 6 taken along line B-B. 8A to 8D are manufacturing flowcharts of the electroacoustic transducer of Fig. 7. 9A and 9B illustrate a partial manufacturing process of an electroacoustic transducer according to another embodiment of the present invention.

Claims (11)

An electroacoustic transducer comprising: a susceptor; at least one vibrating portion coupled to the pedestal and including a piezoelectric conversion layer; and at least one partition structure coupled to the vibrating portion to isolate the vibrating portion a region and a second region, wherein the piezoelectric conversion layer is adapted to convert one of the first acoustic wave and the first electrical signal into the first acoustic wave and the first electrical signal in the first region The piezoelectric conversion layer is adapted to convert one of the second acoustic wave and the second electrical signal into one of the second acoustic wave and the second electrical signal in the second region, and The frequency of the first sound wave is higher than the frequency of the second sound wave. The electroacoustic transducer according to claim 1, wherein a resonance frequency of the first region is higher than a resonance frequency of the second region. The electroacoustic transducer according to claim 1, wherein the piezoelectric conversion layer is adapted to receive the first electrical signal in the first region and deform in the first region to drive the vibrating portion at the An area is vibrated to generate the first sound wave, and the piezoelectric conversion layer is adapted to receive the second electrical signal in the second region and deform in the second region to drive the vibrating portion to vibrate in the second region to generate The second sound wave. The electroacoustic transducer according to claim 1, wherein the vibrating portion is adapted to receive the first acoustic wave and vibrate in the first region to drive the piezoelectric conversion layer to be deformed in the first region to generate the a first electrical signal, and the vibrating portion is adapted to receive the second acoustic wave and vibrate in the second region to drive the piezoelectric conversion layer to deform in the second region to generate the second electrical signal. The electroacoustic transducer according to claim 1, wherein the partition structure is a frame surrounding the first area, and the second area surrounds the frame. The electroacoustic transducer according to claim 1, wherein the piezoelectric conversion layer comprises an upper electrode layer, a piezoelectric material layer and a lower electrode layer, and the piezoelectric material layer is disposed on the upper electrode layer Between the lower electrode layers. The electroacoustic transducer of claim 6, wherein the upper electrode layer comprises at least one first electrode and at least one second electrode, the first electrode being disposed in the first region and adapted to receive or output the a first electrical signal, and the second electrode is disposed in the second area and is adapted to receive or output the second electrical signal. The electroacoustic transducer according to claim 7, wherein the susceptor has at least one electrical contact, and the first electrode is connected to the electrical contact by a line, and the line passes the Two regions, and a width of the second electrode is greater than 1.5 times a width of the line on the second region. The electroacoustic transducer according to claim 1, wherein the base has an opening, the vibrating portion is located in the opening and has a plurality of elastic arms, and is connected to the base by each of the elastic arms. The electroacoustic transducer according to claim 1, wherein the number of the at least one vibrating portion is plural, and the number of the at least one partitioning structure is plural, and the partitioning structures are respectively connected to the vibrating portions. The electroacoustic transducer according to claim 1, wherein a thickness of the partition structure along a vibration direction of the vibrating portion is smaller than a thickness of the susceptor along the vibration direction.