A micro speaker structure

Abstract

The present invention discloses a micro-speaker structure, which relates to the technical field of speakers and provides a micro-speaker structure, which includes a substrate, a diaphragm, a coil, a circuit board and a magnet component. The substrate has a hollow chamber. The diaphragm is arranged on the substrate and covers the hollow chamber. The coil is embedded in the diaphragm. The circuit board is attached to the substrate. The magnet component is arranged on the circuit board and is located in the hollow chamber. The magnet component has a first side facing the coil and a second side opposite to the first side, wherein the first side includes a first magnetic pole region and a second magnetic pole region with different polarities. The present invention can increase the sound pressure of the micro-speaker structure without increasing the size of the micro-speaker structure by providing a novel magnet component having multiple magnetic pole regions on the magnet surface (for example, facing the coil structure).

Description

Technical Field

[0001] The present invention relates to the technical field of loudspeakers, and in particular to a micro loudspeaker structure. Background Art

[0002] As electronic products become smaller and thinner, how to reduce the size of electronic products has become an important issue. Micro electromechanical system (MEMS) technology is a technology that combines semiconductor processing and mechanical engineering. It can effectively reduce the size of components and manufacture multifunctional micro components and micro systems.

[0003] The manufacturing technology of traditional moving coil speakers is quite mature, but the area of ​​traditional moving coil speakers is large and the price is expensive. If the micro-electromechanical system (MEMS) process is used to make moving coil speakers on semiconductor chips, the size and volume will be reduced. However, in addition to reducing the size to facilitate manufacturing, there is still a need to develop micro moving coil speakers with better performance. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above problems existing in the existing micro-speaker structure, the present invention is proposed.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: A micro speaker structure, comprising: a substrate, a diaphragm, a coil, a circuit board and a magnet component. The substrate has a hollow chamber. The diaphragm is arranged on the substrate and covers the hollow chamber. The coil is embedded in the diaphragm. The circuit board is attached to the substrate. The magnet component is arranged on the circuit board and is located in the hollow chamber. The magnet component has a first side facing the coil and a second side opposite to the first side, wherein the first side includes a first magnetic pole region and a second magnetic pole region with different polarities.

[0007] As a preferred solution of the micro-speaker structure described in the present invention, the first side and the second side of the magnet component have different polarities.

[0008] As a preferred solution of the micro-speaker structure described in the present invention, the magnet component has a cylindrical structure, wherein the first magnetic pole region is located in the central region of the first side, and the second magnetic pole region is located in the peripheral region of the first side surrounding the central region.

[0009] As a preferred solution of a micro-speaker structure described in the present invention, the magnet component includes a first magnet and a second magnet, the first magnet has a cylindrical structure, and the second magnet has an annular structure surrounding the cylindrical structure of the first magnet, wherein the first magnet and the second magnet have different polarities at the corresponding first ends adjacent to the first side, and have different polarities at the corresponding second ends adjacent to the second side.

[0010] As a preferred solution of the micro-speaker structure described in the present invention, the magnet component has an opening formed in the first magnet and extending through the first end and the second end of the first magnet.

[0011] As a preferred solution of the micro-speaker structure described in the present invention, the magnet component has an opening formed around the first magnet and separating the first magnet from the second magnet.

[0012] As a preferred solution of a micro-speaker structure described in the present invention, the magnet component is an integrated structure including a first (magnetic) section and a second (magnetic) section, the first section has a cylindrical structure, the second section has an annular structure surrounding the cylindrical structure of the first section, wherein the first section and the second section have different polarities at the corresponding first ends adjacent to the first side, and have different polarities at the corresponding second ends adjacent to the second side.

[0013] As a preferred solution of a micro-speaker structure described in the present invention, the magnet component has a cylindrical structure, wherein the first magnetic pole region is located in the central area of ​​the first side, and the first side also includes a plurality of second magnetic pole regions located around the first magnetic pole region, wherein a non-polar region is provided between the first magnetic pole region and the second magnetic pole region.

[0014] As a preferred solution of a micro-speaker structure described in the present invention, the magnet component is an integrated structure including a first (magnetic) section and multiple second (magnetic) sections, wherein each of the first section and the second section has a cylindrical structure, the second section is located around the first section, and the first section and the second section are surrounded by non-polar sections, wherein the first section and the second section have different polarities at the corresponding first ends adjacent to the first side, and have different polarities at the corresponding second ends adjacent to the second side.

[0015] As a preferred solution of the micro-speaker structure described in the present invention, the first side and the second side of the magnet component have the same polarity.

[0016] As a preferred solution of a micro-speaker structure described in the present invention, the magnet component has a rectangular structure, wherein the first magnetic pole region is located in the middle area of ​​the first side, and the first side also includes a third magnetic pole region, wherein the second magnetic pole region and the third magnetic pole region are located on both sides of the first magnetic pole region and have the same polarity.

[0017] As a preferred solution of a micro-speaker structure described in the present invention, wherein: the magnet component is an integrated structure including a first (magnetic) section, a second (magnetic) section and a third (magnetic) section, wherein each of the first section, the second section and the third section has a rectangular structure, and the second section and the third section are located on both sides of the first section, wherein the first section has a first polarity, and the second section and the third section both have a second polarity different from the first polarity.

[0018] As a preferred solution of the micro-speaker structure described in the present invention, the magnet component further includes a fourth (magnetic) section surrounded by the first section, and the fourth section has the same polarity as the second section and the third section.

[0019] As a preferred solution of a micro-speaker structure described in the present invention, the magnet component includes a permanent magnet and a magnetic conductive element, the permanent magnet is in direct contact with the top surface of the magnetic conductive element, and the magnetic conductive element has a side wall extending from the top surface and surrounding the permanent magnet, wherein the first end of the permanent magnet adjacent to the first side has a different polarity from the second end of the permanent magnet adjacent to the second side, and the magnetic conductive element has a different polarity from the first end of the permanent magnet.

[0020] As a preferred solution of the micro-speaker structure described in the present invention, the coil vertically overlaps with the first magnetic pole region and the second magnetic pole region.

[0021] As a preferred solution of the micro-speaker structure described in the present invention, the micro-speaker structure further includes a packaging cover and a permanent magnet, the packaging cover surrounds the substrate and the diaphragm, wherein the packaging cover has a cover opening exposing a portion of the diaphragm, and the permanent magnet is arranged on the packaging cover.

[0022] As a preferred solution of the micro-speaker structure described in the present invention, the coil is a multi-layer coil including a first layer and a second layer, wherein the first layer has a spiral structure surrounding the central axis of the diaphragm, and the second layer spans the spiral structure of the first layer from above and is electrically connected to the first layer.

[0023] As a preferred solution of the micro-speaker structure described in the present invention, the coil is a multi-layer coil including a first layer and a second layer, wherein the first layer includes a plurality of coaxial sections arranged around the central axis of the diaphragm, and the coaxial sections are electrically connected to each other through the second layer.

[0024] As a preferred solution of the micro-speaker structure described in the present invention, the second layer is symmetrically arranged around the central axis of the diaphragm.

[0025] Some other embodiments of the present invention provide a micro-speaker structure, including: a substrate, a diaphragm, a coil, a circuit board, and a magnet member. The substrate has a hollow chamber. The diaphragm is arranged on the substrate and covers the hollow chamber. The coil is embedded in the diaphragm. The circuit board is attached to the substrate. The magnet member is arranged on the circuit board and is located in the hollow chamber. The magnet member includes a first magnetic segment, a plurality of second magnetic segments surrounding the first magnetic segment, and a non-polar segment portion surrounding the first magnetic segment and the second magnetic segment and located between the first magnetic segment and the second magnetic segment, wherein on the top side of the magnetic pole member facing the coil, the first magnetic segment has a first polarity, and the second magnetic segment has a second polarity different from the first polarity.

[0026] Advantageous effects of the present invention: By providing a novel magnet member having a multi-pole region on the magnet surface (e.g., facing the coil structure), the sound pressure level (SPL) of the micro-speaker structure can be increased without increasing the size of the micro-speaker structure. Therefore, the performance of the micro-speaker structure is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0028] Figure 1 A top view showing a micro speaker structure according to some embodiments;

[0029] Figure 2 According to some embodiments Figure 1 An enlarged view of area I shown in;

[0030] Figures 3 to 7 According to some embodiments, the formation Figure 1 A cross-sectional view of an intermediate stage of a microspeaker structure;

[0031] Figure 8 and Fig. 9 Various views showing a magnet assembly according to some embodiments;

[0032] Fig.10 and Fig.11 Various views showing a magnet assembly according to some embodiments;

[0033] Fig.12Various views showing a magnet assembly according to some embodiments;

[0034] Fig.13 Various views showing a magnet assembly according to some embodiments;

[0035] Fig.14 and Fig.15 Various views showing a magnet assembly according to some embodiments;

[0036] Fig.16 , Fig.17 and Fig.18 Various views showing a magnet assembly according to some embodiments;

[0037] Fig.19 , Fig. 20 and Fig.21 Various views showing a magnet assembly according to some embodiments;

[0038] Fig. 22 shows a cross-sectional view of a magnet member according to some embodiments;

[0039] Fig.23 A cross-sectional view showing a microspeaker structure according to some embodiments;

[0040] Fig.24 A top view showing a micro speaker structure according to some embodiments;

[0041] Fig.25 According to some embodiments Fig.13 An enlarged view of the region J shown in FIG.

[0042] Fig.26 According to some embodiments Fig.13 Cross-sectional view of the microspeaker structure in Figure 2.

[0043] In the figure: 10, 10', 20: micro speaker; 100, 200: substrate; 101, 201: insulating layer; 102, 202: insulating layer; 110, 210: diaphragm; 111, 211: opening; 120, 220: multilayer coil; 121, 221: first layer; 121A: spiral structure; 121B: wave structure; 221A: coaxial section; 122, 222: second layer; 130, 230: dielectric layer; 130A, 230A: through hole; 140, 240: cutting groove; 150, 250: carrier; 151, 251: air hole; 160, 160', 160'', 160''', 260: magnet member; 160A, 260A: top surface / top side / first side; 160B: bottom surface / bottom side / second side; 161: (first) magnet; 161S: first magnetic segment / segment portion; 162: (second) magnet; 162S: second magnetic segment / segment portion; 163S: non-polar segment / segment portion; 1600, 1600': magnet member; 1600A: magnet member; 1610S: first magnetic segment; 1620S: second magnetic segment; 1630S: third magnetic segment; 1640S: fourth magnetic segment; 1610: permanent magnet; 1620: magnetic conductive element; 1621: top surface; 1622: side wall; 170: package cover; 170A: cover opening; 180: permanent magnet; I, J: area; S: hollow chamber; G1, G2: opening; ML: magnetic field lines; X, Y, Z: axes; AA, BB, CC, DD, EE, XX: line. DETAILED DESCRIPTION

[0044] The micro-speaker structures of some embodiments of the present disclosure are described below. However, it should be understood that these embodiments provide many applicable inventive concepts that can be embodied in a variety of specific contexts, and the specific embodiments discussed are only used to illustrate the specific ways of making and using these embodiments, and do not limit the scope of the present disclosure.

[0045] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. It should be understood that each term defined in a commonly used dictionary should be interpreted as having a meaning consistent with the background or context of the relevant technology and the present disclosure, and should not be interpreted in an idealized or overly formal manner, unless otherwise defined herein.

[0046] The disclosure may repeat component symbols and / or letters in various examples. These repetitions are for the purpose of simplicity and clarity and do not in themselves represent a specific relationship between the various embodiments and / or configurations discussed. Some variations of the embodiments are described below. In the embodiments of the different drawings and descriptions, similar component symbols are used to indicate similar components.

[0047] Figure 1 1 is a top view of a micro speaker structure 10 according to some embodiments. The micro speaker structure 10 is an electroacoustic transducer, such as a micro dynamic speaker, which can be disposed in a general electronic product. Figure 1 As shown in FIG. 1 , the micro speaker structure 10 includes a substrate 100, a diaphragm 110, and a multilayer coil 120. The diaphragm 110 is disposed on the substrate 100 and can move relative to the substrate 100. Figure 1 In the example shown in FIG. 1 , in order to show the internal structure of the micro speaker structure 10 , the diaphragm 110 is depicted as transparent.

[0048] In addition, the multilayer coil 120 is embedded in the diaphragm 110, which means that the multilayer coil 120 is not exposed to the outside. The multilayer coil 120 is configured to transmit an electrical signal and drive the diaphragm 110 to deform relative to the substrate 100 according to the electrical signal. Two openings 111 are formed in the diaphragm 110. The multilayer coil 120 includes a first layer 121 and a second layer 122, and the first layer 121 is electrically connected to the second layer 122 in at least one opening 111. The first layer 121 and the second layer 122 are located on different horizontal planes parallel to the XY plane. In the present embodiment, the second layer 122 is higher than the first layer 121, that is, the second layer 122 is closer to the top of the diaphragm 110 than the first layer 121.

[0049] It should be noted that the first layer 121 is electrically connected to the second layer 122 in at least one opening 111 to transmit an electrical signal from a control unit (not shown) to control the operation of the micro speaker structure 10. In this embodiment, the first layer 121 includes a helical structure 121A and a wavy structure 121B. It should be understood that the multilayer coil 120 is schematically shown in FIG. Figure 1 The detailed structure of the multilayer coil 120 (eg, the spiral structure 121A) is as follows: Figure 2 As shown in . The spiral structure 121A is arranged around the central axis O of the diaphragm 110, and the wave structure 121B connects the spiral structure 121A to one of the openings 111. The electrical signal transmitted in the multi-layer coil 120 can force the diaphragm 110 to deform (for example, oscillate) relative to the substrate 100. By providing the wave structure 121B, the diaphragm 110 can be made more flexible and the difficulty of oscillation can be reduced. In addition, the second layer 122 can also include a wave structure.

[0050] Furthermore, a cutting groove 140 is formed in the diaphragm 110, and the cutting groove 140 surrounds the micro-speaker structure 10. Since a plurality of micro-speaker structures 10 may be formed on the wafer, the cutting groove 140 defines the area of ​​each micro-speaker structure 10. In this way, the cutting groove 140 helps to separate the micro-speaker structures 10 from each other using a cutting method such as laser cutting.

[0051] Next reference Figure 2 , which is a diagram showing the Figure 1 An enlarged schematic diagram of area I is shown in FIG. Figure 2 As shown in FIG. 1 , the second layer 122 spans the spiral structure 121A of the first layer 121 from above, and the dielectric layer 130 is disposed between the first layer 121 and the second layer 122 to prevent a short circuit between the first layer 121 and the second layer 122. A through hole 130A (shown in dotted lines) may be formed in the dielectric layer 130 so that the first layer 121 is electrically connected to the second layer 122 through the through hole 130A. Figures 3 to 7 The detailed structure and formation method of the micro speaker structure 10 will be described.

[0052] Figures 3 to 7 According to some embodiments, the formation Figure 1 It should be understood that each of these figures includes a cross-sectional view of an intermediate stage of the microspeaker structure 10. Figure 1 The cross-sectional views along the lines AA, BB and CC are shown in FIG. In this way, the manufacturing process of different parts of the micro-speaker structure 10 can be shown in a single figure. Figures 3 to 7 Two sets of coordinate axes are provided in , wherein a set of coordinate axes on the left corresponds to a cross-sectional view along line AA, and another set of coordinate axes on the right corresponds to a cross-sectional view along line BB and line CC.

[0053] refer to Figure 3 , providing a substrate 100. In some embodiments, the substrate 100 is a portion of a semiconductor wafer and may be formed of silicon (Si). Alternatively, the substrate 100 may include other semiconductor materials, such as germanium; compound semiconductors including silicon carbide (SiC), gallium arsenide (GaAs), gallium phosphide (GaP), gallium nitride (GaN), indium phosphide (InP) and / or indium arsenide (InAs); alloy semiconductors including SiGe, SiGeC, GaAsP, GaInAs and / or InGaP; or combinations thereof.

[0054] Two insulating layers 101 and 102 are formed on the substrate 100, wherein the insulating layer 101 is disposed between the insulating layer 102 and the substrate 100. Each of the insulating layers 101 and 102 includes or is made of silicon dioxide (SiO2) or other suitable insulating materials, and can be formed by thermal oxidation, chemical vapor deposition (CVD), low pressure CVD (LPCVD), atmospheric pressure CVD (APCVD), plasma-enhanced CVD (PECVD) or any other suitable process. The first layer 121 of the multilayer coil 120 is formed on the insulating layer 102 by electroplating or other deposition processes such as physical vapor deposition (PVD), sputtering or evaporation. The material of the first layer 121 includes aluminum silicon alloy, aluminum, copper or any other suitable conductive material. Then, a patterning process (eg, including a lithography process and / or an etching process) is performed on the first layer 121 to produce Figure 1 The spiral structure 121A and the wavy structure 121B are shown in FIG. Subsequently, a dielectric layer 130 is conformally formed on the patterned first layer 121 and the insulating layer 102 by a furnace process, CVD or other suitable deposition process. The dielectric layer 130 may be a carbon-doped oxide or any other suitable insulating material.

[0055] Then, in Figure 4 In the process, the dielectric layer 130 is patterned (e.g., by a lithography process and / or an etching process) to form a through hole 130A in the dielectric layer 130, thereby exposing the first layer 121 below. Then, the second layer 122 of the multilayer coil 120 is formed on the dielectric layer 130 and the first layer 121 using electroplating or other deposition processes such as PVD, sputtering, or evaporation. The material of the second layer 122 includes an aluminum silicon alloy, aluminum, copper, or any other suitable conductive material. Then, the second layer 122 is subjected to a patterning process (e.g., including a lithography process and / or an etching process), leaving a portion located on the dielectric layer 130 or in the through hole 130A.

[0056] It should be noted that the patterned dielectric layer 130 leaves only the portion required to electrically insulate the first layer 121 from the second layer 122. By removing the unnecessary portion of the dielectric layer 130, the diaphragm 110 (see Figure 5 ) can be more flexible, thereby improving the performance of the micro speaker structure 10.

[0057] Although not shown, in some cases, a protective layer (also referred to as a passivation layer) may also be conformally formed on the multilayer coil 120 for protection. In some embodiments, the protective layer has a multilayer structure, for example, including an oxide layer (e.g., silicon oxide) and a nitride layer (e.g., silicon nitride) located on the oxide layer. Alternatively, the protective layer may have a single-layer structure, for example, having a single nitride layer. The protective layer may be formed by, for example, CVD, PVD, or other suitable processes.

[0058] Then, in Figure 5 In the embodiment, a diaphragm 110 is formed on the structure described above, so that the multilayer coil 120 and the dielectric layer 130 are embedded in the diaphragm 110 (i.e., they are not exposed to the outside); the diaphragm 110 can be formed by spin coating or any other suitable process. In some embodiments, the diaphragm 110 includes or is made of polydimethylsiloxane (PDMS), phenolic epoxy resin (e.g., SU-8), polyimide (PI), or a combination thereof. In one example, the diaphragm 110 is formed of PDMS, and the Young's modulus of the diaphragm 110 is in a range between about 1 MPa and about 100 GPa. Compared with a diaphragm formed of polyimide, the diaphragm 110 formed of PDMS has a smaller Young's modulus and a softer film structure, which allows the diaphragm 110 to have a larger displacement, thereby generating a larger sound amplitude.

[0059] then, Figure 6 In the embodiment, the diaphragm 110 is patterned to form a plurality of openings 111 (only one opening 111 is shown) in the diaphragm 110 and a cutting groove 140 surrounding the diaphragm 110. In some embodiments where the diaphragm 110 is made of a photosensitive material (e.g., a photopolymer material), the openings 111 and the cutting grooves 140 may be formed by using lithography and etching techniques. In other embodiments, where the diaphragm 110 is made of a non-photosensitive material, the openings 111 and the cutting grooves 140 may be formed by using drilling, cutting, and / or other suitable patterning techniques. The openings 111 may expose the second layer 122 below, so that the first layer 121 is electrically connected to the second layer 122 in one of the openings 111 (as described above). In other words, when viewed along a vertical direction (e.g., the Z-axis direction), one of the openings 111 of the diaphragm 110 may overlap with one of the through holes 130A. The cutting grooves 140 may facilitate a cutting process to separate a plurality of micro speaker structures 10, as described above.

[0060] Still refer to Figure 6, a deep reactive ion etching process or an etching process in which an etchant (e.g., ammonium hydroxide (NH4OH), hydrofluoric acid (HF), deionized water, tetramethylammonium hydroxide (TMAH), potassium hydroxide (KOH)) is applied on the bottom surface of the substrate 100 to form a hollow chamber S in the substrate 100. After the etching process, the diaphragm 110 covers the hollow chamber S (e.g., is suspended above the hollow chamber S). It should be noted that the insulating layers 101 and 102 may act as an etching stop layer during the etching process. Therefore, the diaphragm 110 and the multilayer coil 120 are protected from being etched.

[0061] Then, in Figure 7 In the embodiment, a carrier 150 (e.g., a printed circuit board (PCB)) is disposed or attached on the bottom surface of the substrate 100. Therefore, the substrate 100 is located between the carrier 150 and the diaphragm 110. The carrier 150 has one or more air holes 151, which allow the hollow chamber S to communicate with the external environment.

[0062] In addition, the magnet member 160 is disposed on the carrier 150 and in the hollow chamber S. The magnet member 160 is used to cooperate with the overlying multi-layer coil 120 (i.e., the magnetic field generated by the magnet member 160 interacts with the current flowing through the multi-layer coil 120) to generate a force (e.g., a Z-axis force) along the normal direction of the diaphragm 110 (i.e., the vertical / Z-axis direction, which is perpendicular to the top surface of the diaphragm 110), and the diaphragm 110 can be subjected to the force to vibrate / oscillate relative to the substrate 100, thereby generating sound.

[0063] It should be understood that the size (e.g., thickness and / or area) of the diaphragm 110 of the micro-speaker structure 10 is smaller than the size of the diaphragm of a conventional dynamic speaker. However, the size of the diaphragm is related to the sound pressure level (SPL). Therefore, how to increase the SPL without increasing the size of the structure is a problem that needs to be solved. The following describes a novel magnet component design for increasing the SPL proposed in accordance with an embodiment of the present disclosure.

[0064] refer to Figure 8 and Fig. 9 , Figure 8 The magnet member 160 (ie, Figure 7 A top view of the magnet member 160 in FIG. Fig. 9 Shown along Figure 81 is a cross-sectional view of the magnet member 160 taken along line XX in FIG. 1 . In the present embodiment, the magnet member 160 is composed of two magnets (161, 162), but more magnets (e.g., three, four, etc.) may be used in other embodiments. In some embodiments, each of the magnets 161 and 162 is a permanent magnet, such as a neodymium iron boron magnet. In other embodiments, other suitable permanent magnet materials may also be used.

[0065] exist Figure 8 and Fig. 9 In the example, the magnet member 160 has a cylindrical structure and includes a first magnet 161 having a cylindrical structure and a second magnet 162 having a (circular) ring structure surrounding the cylindrical structure. In some cases, the inner diameter of the second magnet 162 can be substantially equal to the diameter of the first magnet 161, but the present disclosure is not limited to this (to be described later). In addition, the thickness of the first magnet 161 (e.g., along the Z-axis direction) can be substantially equal to the thickness of the second magnet 162. Therefore, the top surfaces of the magnets 161 and 162 form the top surface (or top side) 160A of the magnet member 160 (e.g., facing the multilayer coil 120, see Figure 7 ), and the bottom surfaces of the magnets 161 and 162 form the bottom surface (or bottom side) 160B of the magnet member 160.

[0066] In some embodiments, the first magnet 161 and the second magnet 162 have different polarities at respective first ends (e.g., upper ends) adjacent to the top side 160A (or first side), and have different polarities at respective second ends (e.g., lower ends) adjacent to the bottom side 160B (or second side). Figure 8 and Fig. 9 In the example of FIG. 10 , the first ends of the magnets 161 and 162 are N poles and S poles, respectively, and the second ends of the magnets 161 and 162 are S poles and N poles, respectively. However, in some alternative embodiments as shown in FIGS. 10 and 11 , the N poles and S poles of the magnets 161 and 162 may be reversed.

[0067] Through the above configuration, the first side 160A (hereinafter also referred to as the magnet surface) of the magnet member 160 can have a first magnetic pole region (where the first magnet 161 is located) and a second magnetic pole region (where the second magnet 162 is located) with different polarities. This helps increase the magnetic field lines (for example, see Figure 7The distribution of magnetic field lines ML in the magnet member 160 is shown in FIG. 1 . On the first side 160A (or the top side) (facing the multi-layer coil 120) of the magnet member 160, the magnetic field (e.g., the horizontal or planar magnetic field) can be enhanced. In other words, the magnetic field on the first side 160A of the magnet member 160 (e.g., the horizontal or planar magnetic field) can be enhanced. Therefore, the force in the normal direction of the diaphragm 110 generated by the interaction between the magnet member 160 and the multi-layer coil 120 is also increased, so that the SPL can be increased. In some embodiments, preferably, the multi-layer coil 120 vertically overlaps with both the first magnetic pole region and the second magnetic pole region (i.e., the projected area of ​​the multi-layer coil 120 on the first side 160A can overlap with part of the first magnetic pole region and part of the second magnetic pole region) to increase the interaction between the magnet member 160 and the multi-layer coil 120.

[0068] In addition, it should be understood that because the magnetic field generated by the magnet member 160 (e.g., the magnetic field on the magnet surface) is large, the magnet member 160 can have a reduced thickness (or height) in some cases compared to a conventional magnet member (i.e., having a single magnetic pole at each end) to achieve the same SPL. This is beneficial for reducing the size (e.g., thickness) of the micro speaker structure 10. In addition, since the multi-pole region on the magnet surface can well confine (or concentrate) the magnetic field lines ML on the first side 160A, environmental interference can be reduced.

[0069] Fig.12 Various views of a magnet member 160' according to some alternative embodiments are shown, wherein the upper half of the figure shows a cross-sectional view of the magnet member 160' and the lower half shows a top view of the magnet member 160'. The magnet member 160' is similar to the magnet member 160 described above, except that the magnet member 160' also has an opening G1 formed in the first magnet 161 and extending through the first end (or upper end) and the second end (or lower end) of the first magnet 161. In some cases, the opening G1 can be aligned with the central axis of the first magnet 161. By forming the opening G1, the distribution of magnetic field lines (not specifically shown) near the opening G1 can be increased.

[0070] Fig.13Various views of a magnet member 160'' according to other alternative embodiments are shown, wherein the upper half of the figure shows a cross-sectional view of the magnet member 160'' and the lower half shows a top view of the magnet member 160''. The magnet member 160'' is similar to the above-mentioned magnet member 160, except that the magnet member 160'' also has an opening G2 (e.g., an annular opening) formed around the first magnet 161 and separating the first magnet 161 from the second magnet 162. In this way, the inner diameter of the second magnet 162 is larger than the diameter of the first magnet 161. Similarly, the presence of the opening G2 helps to increase the distribution of magnetic lines of force (not specifically shown) near the opening G2. It should be understood that, depending on the relative position of the multi-layer coil 120, the opening G1 and / or the opening G2 can be arbitrarily applied to the above-mentioned magnet member, and the position or number of the openings (G1, G2) can also be changed to enhance the force generated in the normal direction of the diaphragm 110.

[0071] In addition, although the magnet component 160 (or 160' or 160") described above is composed of two magnets 161 and 162, in different embodiments, the magnet component 160 can also be an integral structure (i.e., an integrally molded structure). For example, such an (integrally molded) magnet component 160 can be formed by magnetization technology (e.g., axial magnetization and / or radial magnetization) to have a first magnetic segment 161S and a second magnetic segment 162S, wherein the configuration, structure, and magnetic properties of the first magnetic segment 161S and the second magnetic segment 162S are the same or similar to the configuration, structure, and magnetic properties of the first magnet 161 and the second magnet 162 described above (e.g., see Figures 8 to 13 ). The details of magnetization technology will not be discussed here.

[0072] Many changes and / or modifications may be made to the embodiments of the present disclosure. Some variations of some embodiments are described below.

[0073] refer to Fig.14 and Fig.15 , Fig.14 shows a perspective view of a magnet member 160''' according to some embodiments, and Fig.15 Show Fig.14A top view of the magnet member 160''' in FIG. 1 . In the present embodiment, the magnet member 160''' is an integral structure (i.e., an integrally molded structure), including a first magnetic segment 161S and a plurality of second magnetic segments 162S located around the first magnetic segment 161S, and having a non-polar segment 163S between the first magnetic segment 161S and the second magnetic segment 162S. The non-polar segment 163S may also surround the first magnetic segment 161S and the second magnetic segment 162S, so that only the upper and lower ends of these magnetic polar regions (161S, 162S) are exposed. Each segment 161S, 162S, and 163S may have a cylindrical structure (see Fig.14 ).

[0074] In addition, the first magnetic segment 161S and the second magnetic segment 162S have different polarities at respective first ends (e.g., upper ends) adjacent to the first side 160A, and have different polarities at respective second ends (e.g., lower ends) adjacent to the second side 160B, similar to the first and second magnets (161, 162) described above. Fig.14 and Fig.15 In the example, the first ends of the first magnetic segment 161S and the second magnetic segment 162S are respectively N poles and S poles, while the second ends of the first magnetic segment 161S and the second magnetic segment 162S are respectively S poles and N poles. However, in some other embodiments, the N poles and S poles of the first magnetic segment 161S and the second magnetic segment 162S can be swapped. Similarly, this (integrally formed) magnet component 160''' can be formed by magnetizing technology (e.g., axial magnetizing). By having multiple magnetic pole regions (e.g., a first magnetic pole region located in the center region and multiple second magnetic pole regions surrounding the first magnetic pole region) on the magnet surface (e.g., the top side 160A), the magnet component 160''' can also achieve similar advantages as the above-mentioned magnet component 160 (or 160' or 160''), such as improving SPL.

[0075] refer to Figures 16 to 18 , Fig.16 shows a perspective view of a magnet member 1600 according to some embodiments, Fig.17 Show Fig.16 A top view of the magnet assembly 1600 in FIG. Fig.18 Show Fig.161600. In the present embodiment, the magnet member 1600 has a rectangular parallelepiped structure and is an integral structure (i.e., an integrally molded structure) including a first magnetic segment 1610S, a second magnetic segment 1620S, and a third magnetic segment 1630S. The first magnetic segment 1610S is located in the middle area of ​​the magnet member 1600, and the second magnetic segment 1620S and the third magnetic segment 1630S are located on both sides of the first magnetic segment 1610S. Each segment 1610S, 1620S, and 1630S may have a rectangular parallelepiped structure and may extend from a first side 160A (facing the multilayer coil 120) of the magnet member 1600 to a second side 160B (see Fig.16 ).

[0076] In addition, the first magnetic segment 1610S has a first polarity (e.g., N pole), and the second magnetic segment 1620S and the third magnetic segment 1630S each have a second polarity (e.g., S pole) different from the first polarity. Similarly, such a (integrally formed) magnet component 1600 can be formed by magnetization technology. By having a multi-pole region on the magnet surface (e.g., top side 160A), the magnet component 1600 can also achieve similar advantages as the above-mentioned magnet component 160 (or 160' or 160''), such as improving SPL.

[0077] Similarly, Fig.19 , 20 21 show various views (e.g., a perspective view, a top view, and a side view) of a magnet member 1600' according to some embodiments. The magnet member 1600' is similar to the magnet member 1600 described above, except that the magnet member 1600' further includes a fourth magnetic segment 1640S. The fourth magnetic segment 1640S may be surrounded by the first magnetic segment 1610S (e.g., embedded in the first magnetic segment 1610S), and may extend from a side wall of the magnet member 1600' to an opposite side wall, such that the fourth magnetic segment 1640S is exposed through the first magnetic segment 1610S. In addition, the fourth magnetic segment 1640S has the same magnetic properties as the second magnetic segment 1620S and the third magnetic segment 1630S (i.e., has a different magnetic property from the first magnetic segment 1610S). By forming the fourth magnetic segment 1640S, the stability of the magnetic flux loop (not specifically shown) may be further improved. In this way, the reliability of the micro speaker structure 10 is also improved.

[0078] Fig. 22 FIG. 1 shows a cross-sectional view of a magnet assembly 1600A according to some embodiments. The magnet assembly 1600A includes a permanent magnet 1610 and a magnetically conductive element 1620. The permanent magnet 1610 may be similar to the magnet assembly 1600A shown in FIG. Figures 8 to 111600A. The material of the magnetic conductive element 1620 may include molybdenum metal, silicon steel, ferrite, or any other suitable magnetic conductive material. The permanent magnet 1610 is placed on (e.g., in direct contact with) the top surface 1621 of the magnetic conductive element 1620, and the magnetic conductive element 1620 has a side wall 1622 extending from the top surface 1621 and surrounding the permanent magnet 1610. The side wall 1622 and the top surface of the permanent magnet 1610 may be substantially at the same level (i.e., at the same height in the Z-axis direction), thereby forming the top side 160A of the magnet member 1600A.

[0079] Through the above configuration, the magnetic conductive element 1620 (e.g., the side wall 1622) and the first end (e.g., the upper end) of the permanent magnet 1610 can have different polarities. Thus, a multi-pole region can be realized on the top side 160A of the magnet component 1600A. Therefore, the magnet component 1600A can also achieve similar advantages as the above-mentioned magnet component 160 (or 160' or 160''), such as improving SPL.

[0080] It should be understood that the structure, configuration and manufacturing method of the magnet member described herein are only illustrative and are not intended to and should not be interpreted as limiting the present disclosure. Once the present disclosure is known, many alternatives and modifications will be apparent to those skilled in the art.

[0081] Fig.23 A cross-sectional view of a micro-speaker structure 10' according to some embodiments is shown. The micro-speaker structure 10' is similar to the micro-speaker structure 10 described above, except that the micro-speaker structure 10' further includes a packaging cover 170 and a permanent magnet 180. The packaging cover 170 is disposed on or attached to the carrier 150 and is designed to surround and protect the substrate 100 and the diaphragm 110. The packaging cover 170 may have a cover opening 170A to allow acoustic energy caused by the vibration of the diaphragm 110 to propagate outside the micro-speaker structure 10'. In some embodiments, the packaging cover 170 is made of a metal material having a magnetic permeability lower than about 1.25×10-4 H / m, such as gold (Au), copper (Cu), aluminum (Al), or a combination thereof, which helps to maintain or confine the magnetic field in the micro-speaker structure 10'.

[0082] The permanent magnet 180 is disposed above the diaphragm 110 (eg, attached to the packaging cover 170). Fig.23In the example of the present invention, the permanent magnet 180 may have an annular structure that matches the shape of the cover opening 170A of the package cover 170 (for example, the cover opening 170A is circular, and the permanent magnet 180 is annular, but the present disclosure is not limited thereto), and may be disposed below the cover opening 170A. In some alternative embodiments (not shown), the permanent magnet 180 may be disposed above the cover opening 170A of the package cover 170. In some embodiments, the permanent magnet 180 is a neodymium iron boron magnet. In other embodiments, other suitable permanent magnet materials may also be used.

[0083] The permanent magnet 180 and the magnet member 160 can attract each other to increase the deflection of the planar magnetic field. Therefore, the force generated by the current passing through the multilayer coil 120 and the planar magnetic field in the normal direction of the diaphragm 100 increases, so that the diaphragm 110 has a higher frequency response, thereby improving the performance of the micro speaker structure 10'.

[0084] In some embodiments, the distance between the magnet member 160 and the permanent magnet 180 may be in a range between about 200 μm and about 1000 μm. If the distance is greater than 1000 μm, there may not be sufficient attraction between the magnet member 160 and the permanent magnet 180 to increase the deflection of the planar magnetic field, resulting in a smaller frequency response of the micro-speaker structure. Therefore, the performance of the micro-speaker structure is reduced. If the distance is less than 200 μm, when the diaphragm 110 is deformed up and down relative to the substrate 100, it may repeatedly contact and collide with the magnet member 160 and / or the permanent magnet 180, causing damage to the micro-speaker structure. Therefore, the reliability of the micro-speaker structure is reduced.

[0085] Fig.24 FIG. 2 is a top view showing a micro speaker structure 20 according to some other embodiments. It should be understood that the micro speaker structure 20 may include Figure 1 The same or similar components as those of the micro-speaker structure 10 shown in FIG. 1 are denoted by similar numbers, and their details are not repeated here. For example, the micro-speaker structure 20 includes a substrate 200, a diaphragm 210, and a multi-layer coil 220. Similarly, it should be noted that in Fig.24 In the example shown in FIG. 2 , in order to show the internal structure of the micro speaker structure 20 , the diaphragm 210 is depicted as transparent.

[0086] In this embodiment, the multilayer coil 220 is also embedded in the diaphragm 210 and includes a first layer 221 and a second layer 222, which are located on different horizontal planes parallel to the XY plane. Figure 1The difference between the micro-speaker structure 10 shown in FIG. 1 is that the first layer 221 of the multi-layer coil 220 includes a plurality of coaxial segments 221A arranged around the central axis O of the diaphragm 210, and these coaxial segments 221A are electrically connected to each other through the second layer 222. It should be understood that the multi-layer coil 220 is schematically shown in FIG. Fig.24 The detailed structure of the multilayer coil 220 (eg, the coaxial section 221A) is as follows: Fig.25 In addition, the second layer 222 is also symmetrically arranged around the central axis O of the diaphragm 210 .

[0087] Fig.25 It is shown Fig.24 An enlarged schematic diagram of region J is shown in FIG. Fig.25 As shown in FIG. 2 , the second layer 222 interconnects the separated coaxial segments 221A of the first layer 221. The dielectric layer 230 is disposed between the first layer 221 and the second layer 222 to prevent a short circuit between the first layer 221 and the second layer 222. A through hole 230A (shown in dotted lines) may be formed in the dielectric layer 230, and the first layer 221 is electrically connected to the second layer 222 through the through hole 230A.

[0088] Fig.26 It is shown Fig.24 Schematic cross-sectional view of the micro-speaker structure 20 shown in FIG. It should be understood that Fig.26 Including along Fig.24 A cross-sectional view of line DD and line EE shown in FIG. Fig.26 Two sets of coordinate axes are provided in , wherein a set of coordinate axes on the left corresponds to the cross-sectional view along line DD , and another set of coordinate axes on the right corresponds to the cross-sectional view along line EE .

[0089] The detailed structure of the micro speaker structure 20 is as follows Fig.26 The structure and manufacturing process of the micro-speaker structure 20 are substantially the same as those of the micro-speaker structure 10, and the details thereof are not repeated here. Fig.26 As shown in , the second layer 222 of the multi-layer coil 220 is substantially evenly distributed in the diaphragm 210. As a result, when the diaphragm 210 oscillates relative to the substrate 200, the distribution of the oscillation force can be more even. Therefore, the total harmonic distortion (THD) value of the micro-speaker structure 20 can be reduced, and the service life of the micro-speaker structure 20 can be extended.

[0090] As described above, the embodiments of the present disclosure provide a micro-speaker structure having a novel magnet component design. The micro-speaker structure can be formed using micro-electromechanical system (MEMS) technology. Therefore, the size of the micro-speaker structure can be significantly reduced. In addition, by providing a novel magnet component having a multi-pole region on the magnet surface (e.g., facing the coil structure), the sound pressure level (SPL) of the micro-speaker structure can be increased without increasing the size of the micro-speaker structure. Therefore, the performance of the micro-speaker structure is also improved.

[0091] Although the embodiments of the present disclosure and their advantages are described in detail above, it should be understood that various changes, substitutions and modifications can be made to the present disclosure without departing from the spirit and scope of the present disclosure defined by the attached claims. For example, it will be readily understood by those skilled in the art that many of the features, functions, processes and materials described herein can be varied while remaining within the scope of the present disclosure. In addition, the scope of the present application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, material compositions, tools, methods and steps described in the specification. As a person of ordinary skill in the art will easily understand from the present disclosure, according to the present disclosure, processes, machines, manufactures, material compositions, tools, methods or steps that are currently available or will be developed in the future and perform substantially the same functions as the corresponding embodiments described in the present disclosure or achieve substantially the same results can be utilized. Therefore, the attached claims are intended to include these processes, machines, manufactures, material compositions, tools, methods or steps within their scope. In addition, each claim constitutes a separate embodiment, and the combination of different claims and embodiments is within the scope of the present disclosure.

[0092] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A micro speaker structure, characterized in that: include: a substrate having a hollow cavity; a diaphragm, disposed on the substrate and covering the hollow chamber; a coil embedded in the diaphragm; a circuit board attached to the base plate; and a magnet member, disposed on the circuit board and located in the hollow chamber, wherein the magnet member has a first side facing the coil and a second side opposite to the first side, and wherein the first side includes a first magnetic pole region and a second magnetic pole region having different polarities; wherein the first side and the second side of the magnet member have different polarities, the magnet member has a cylindrical structure, wherein the first magnetic pole region is located at a central region of the first side, and wherein the first side further includes a plurality of second magnetic pole regions located around the first magnetic pole region, wherein a non-polar region is located between the first magnetic pole region and the second magnetic pole regions; The magnet component is an integral structure including a first section and a plurality of second sections, wherein the first section and each of the second sections has a cylindrical structure, the second sections are located around the first section, and the first section and the second sections are surrounded by a non-polar section, and wherein the first section and the second sections have different polarities at the corresponding first ends adjacent to the first side, and have different polarities at the corresponding second ends adjacent to the second side.

2. A micro speaker structure according to claim 1, characterized in that: The magnet component has a cylindrical structure, wherein the first magnetic pole region is located in a central region of the first side, and the second magnetic pole region is located in a peripheral region of the first side surrounding the central region.

3. A micro speaker structure according to claim 2, characterized in that: The magnet component includes a first magnet and a second magnet, the first magnet has a cylindrical structure, the second magnet has an annular structure surrounding the cylindrical structure of the first magnet, and the first magnet and the second magnet have different polarities at the corresponding first ends adjacent to the first side, and have different polarities at the corresponding second ends adjacent to the second side.

4. A micro speaker structure according to claim 3, characterized in that: The magnet member has an opening formed in the first magnet and extending through the first end and the second end of the first magnet.

5. A micro speaker structure according to claim 4, characterized in that: The magnet member has an opening formed around the first magnet and separating the first magnet from the second magnet.

6. The micro speaker structure according to claim 2, characterized in that: The magnet component is an integral structure including a first section and a second section, the first section having a cylindrical structure, the second section having an annular structure surrounding the cylindrical structure of the first section, and wherein the first section and the second section have different polarities at the corresponding first ends adjacent to the first side, and have different polarities at the corresponding second ends adjacent to the second side.

7. A micro speaker structure, characterized in that: include: a substrate having a hollow cavity; a diaphragm, disposed on the substrate and covering the hollow chamber; a coil embedded in the diaphragm; a circuit board attached to the base plate; and a magnet member, disposed on the circuit board and located in the hollow chamber, The magnet member has a first side facing the coil and a second side opposite to the first side, and the first side includes a first magnetic pole region and a second magnetic pole region with different polarities; the first side and the second side of the magnet member have the same polarity; The magnet component has a rectangular parallelepiped structure, wherein the first magnetic pole region is located in a middle region of the first side, and wherein the first side also includes a third magnetic pole region, wherein the second magnetic pole region and the third magnetic pole region are located on both sides of the first magnetic pole region and have the same polarity, and the magnet component is an integrated structure including a first section, a second section and a third section, wherein each of the first section, the second section and the third section has a rectangular parallelepiped structure, and the second section and the third section are located on both sides of the first section, and The first section has a first polarity, and the second section and the third section both have a second polarity different from the first polarity; the magnet component also includes a fourth section surrounded by the first section, and the fourth section has the same polarity as the second section and the third section.

8. A micro speaker structure according to claim 1 or 7, characterized in that: The magnet component includes a permanent magnet and a magnetic conductive element, wherein the permanent magnet is in direct contact with a top surface of the magnetic conductive element, and the magnetic conductive element has a side wall extending from the top surface and surrounding the permanent magnet, and A first end of the permanent magnet adjacent to the first side and a second end of the permanent magnet adjacent to the second side have different polarities, and the magnetic conductive element and the first end of the permanent magnet have different polarities.

9. A micro-speaker structure according to claim 1 or 7, characterized in that: The coil vertically overlaps both the first magnetic pole region and the second magnetic pole region.

10. The micro-speaker structure as claimed in claim 1 or 7, further comprising: a packaging cover surrounding the substrate and the diaphragm, wherein the packaging cover has a cover opening exposing a portion of the diaphragm; as well as A permanent magnet is disposed on the packaging cover.

11. A micro speaker structure according to claim 1 or 7, characterized in that: The coil is a multi-layer coil including a first layer and a second layer, wherein the first layer has a spiral structure surrounding a central axis of the diaphragm, and the second layer spans over the spiral structure of the first layer from above and is electrically connected to the first layer.

12. A micro speaker structure according to claim 1 or 7, characterized in that: The coil is a multi-layer coil including a first layer and a second layer, wherein the first layer includes a plurality of coaxial sections arranged around a central axis of the diaphragm, and the coaxial sections are electrically connected to each other through the second layer.

13. A micro speaker structure according to claim 12, characterized in that: The second layer is symmetrically arranged around the central axis of the diaphragm.

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