Patent Publication Number: US-11395073-B2

Title: Sound producing package structure and method for packaging sound producing package structure

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional application No. 63/012,089, filed on Apr. 18, 2020, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a sound producing package structure and a method for packaging a sound producing package structure, and more particularly, to a sound producing package structure and a method for packaging a sound producing package structure where a surface mount technology (SMT) is used. 
     2. Description of the Prior Art 
     Nowadays, a surface mount technology (SMT) is widely used in a package structure, wherein the surface mount technology is an assembly technology in which electronic components are directly connected onto a surface of a substrate (e.g., a circuit board) with printed conductive elements (e.g. solders). The surface mount technology has the following advantages: 1) The electronic components in the package structure can be disposed in high density, such that the size of the package structure can be decreased (e.g., the package structure can be miniaturized); 2) The surface mount technology has the high reliability; 3) The highly automatized formation of the package structure can be achieved by the surface mount technology, so as to decrease the cost of the package structure and enhance the productivity of the package structure. 
     However, the surface mount technology cannot be used in a conventional speaker because the conventional speaker cannot tolerate the process temperature of the surface mount technology. For example, if the surface mount technology is used in the conventional speaker, the electronic component(s) and/or structure(s) of the conventional speaker can be damaged due to the process temperature of the surface mount technology, such that the conventional speaker cannot be normally operated after processing the surface mount technology. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary objective of the present invention to provide a sound producing package structure and a method for packaging a sound producing package structure where a surface mount technology is used. 
     An embodiment of the present invention provides a sound producing package structure configured to produce sound, wherein the sound producing package structure includes a substrate, a sound producing component and a conductive adhesive layer. The sound producing component is disposed on the substrate, and the sound producing component is configured to generate an acoustic wave corresponding to an input audio signal. The conductive adhesive layer is disposed between the substrate and the sound producing component by a surface mount technology. 
     An embodiment of the present invention further provides a method for packaging a sound producing package structure. The method includes: providing a substrate; forming a sound producing component, wherein the sound producing component is configured to generate an acoustic wave corresponding to an input audio signal; and disposing the sound producing component on the substrate via a conductive adhesive layer by using a surface mount technology. 
     In the present invention, according to the present invention, the surface mount technology is used to manufacture the sound producing package structure, the highly automatized formation of the sound producing package structure can be achieved, and/or the sound producing package structure can be miniaturized more. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a cross sectional view illustrating a sound producing component according to a first embodiment of the present invention. 
         FIG. 2  is a schematic diagram of a top view illustrating a relation of base openings and membranes according to the first embodiment of the present invention. 
         FIG. 3  is a schematic diagram of a cross sectional view illustrating a sound producing package structure according to the first embodiment of the present invention. 
         FIG. 4  is a schematic diagram of a bottom view illustrating an arranged relation of substrate conductive pads, a substrate opening, an enclosing ring structure, base openings and membranes according to the first embodiment of the present invention. 
         FIG. 5  is a schematic diagram of a bottom view illustrating a relation of substrate conductive pads, a substrate opening, an enclosing ring structure, base openings and membranes according to a second embodiment of the present invention. 
         FIG. 6  is a schematic diagram of a cross sectional view illustrating a sound producing package structure according to a third embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     To provide a better understanding of the present invention to those skilled in the art, preferred embodiments and typical material or range parameters for key components will be detailed in the follow description. These preferred embodiments of the present invention are illustrated in the accompanying drawings with numbered elements to elaborate on the contents and effects to be achieved. It should be noted that the drawings are simplified schematics, and the material and parameter ranges of key components are illustrative based on the present day technology, and therefore show only the components and combinations associated with the present invention, so as to provide a clearer description for the basic structure, implementing or operation method of the present invention. The components would be more complex in reality and the ranges of parameters or material used may evolve as technology progresses in the future. In addition, for ease of explanation, the components shown in the drawings may not represent their actual number, shape, and dimensions; details may be adjusted according to design requirements. 
     In the following description and in the claims, the terms “include”, “comprise” and “have” are used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to . . . ”. Thus, when the terms “include”, “comprise” and/or “have” are used in the description of the present invention, the corresponding features, areas, steps, operations and/or components would be pointed to existence, but not limited to the existence of one or a plurality of the corresponding features, areas, steps, operations and/or components. 
     When the corresponding component such as layer or area is referred to “on another component (or the variant thereof)”, it may be directly on another component, or other component may exist between them. On the other hand, when the component is referred to “directly on another component (or the variant thereof)”, any component does not exist between them. Furthermore, when a component A 1  is disposed on a component A 2 , the component A 1  may be situated on upper side, lower side, left side, right side or any other suitable side of the component A 2 . 
     It will be understood that when an element or layer is referred to as being “connected to” or “contact with” another element or layer, it can be directly connected to (or directly contact with) the other element or layer, or intervening elements or layers may be presented. In contrast, when an element is referred to as being “directly connected to” or “directly contact with” another element or layer, there are no intervening elements or layers presented. 
     In the following description and in the claims, when “a B 1  component is formed by/of B 2 ”, B 2  exist in the formation of B 1  component or B 2  is used in the formation of B 1  component, and the existence and use of one or a plurality of other features, areas, steps, operations and/or components are not excluded in the formation of B 1  component. 
     Although terms such as first, second, third, etc., may be used to describe diverse constituent elements, such constituent elements are not limited by the terms. The terms are used only to discriminate a constituent element from other constituent elements in the specification, and the terms do not relate to the sequence of the manufacture if the specification do not describe. The claims may not use the same terms, but instead may use the terms first, second, third, etc. with respect to the order in which an element is claimed. Accordingly, in the following description, a first constituent element may be a second constituent element in a claim. 
     It should be noted that the technical features in different embodiments described in the following can be replaced, recombined, or mixed with one another to constitute another embodiment without departing from the spirit of the present invention. 
     Referring to  FIG. 1  to  FIG. 4 ,  FIG. 1  is a schematic diagram of a cross sectional view illustrating a sound producing component according to a first embodiment of the present invention,  FIG. 2  is a schematic diagram of a top view illustrating a relation of base openings and membranes according to the first embodiment of the present invention,  FIG. 3  is a schematic diagram of a cross sectional view illustrating a sound producing package structure according to the first embodiment of the present invention, and  FIG. 4  is a schematic diagram of a bottom view illustrating an arranged relation of substrate conductive pads, a substrate opening, an enclosing ring structure, base openings and membranes according to the first embodiment of the present invention, wherein boundaries of the membranes  120  in  FIG. 2  are shown by the dash lines, and boundaries of the membranes  120  and boundaries of the base openings  110   a  in  FIG. 4  are shown by the dash lines. Note that any suitable sound producing component can be used in the present invention, and  FIG. 1  to  FIG. 4  show an exemplary sound producing component. As shown in  FIG. 1  to  FIG. 4 , the sound producing package structure PAS configured to produce sound includes a substrate SB, a sound producing component PC and a conductive adhesive layer CAL, wherein the sound producing component PC is disposed on the substrate SB and configured to generate an acoustic wave corresponding to an input audio signal, and the conductive adhesive layer CAL is disposed between the substrate SB and the sound producing component PC by a surface mount technology. That is to say, the surface mount technology can make the conductive adhesive layer CAL adhere to the sound producing component PC and the substrate SB, such that the sound producing component PC is disposed on the substrate SB. 
     In the present invention, since the surface mount technology is performed, the sound producing component PC needs to be designed for being capable of tolerating a highest process temperature of the surface mount technology. As the result, the sound producing component PC has a heat resistant temperature which has an upper bound higher than the highest process temperature of the surface mount technology, such that the breakdown of the sound producing component PC would not occur and the sound producing component PC would maintain its normal operation after performing the surface mount technology. In some embodiments, the highest process temperature of the surface mount technology may range from 240° C. to 250° C., and therefore, the upper bound of the heat resistant temperature of the sound producing component PC may be higher than 240° C. or higher than 250° C., but not limited thereto. Moreover, in some embodiments, each material contained in the sound producing component PC has a heat resistant temperature which has an upper bound higher than the highest process temperature of the surface mount technology, so as to ensure that the sound producing component PC would not be damaged during surface mounting technology. For example, each material contained in the sound producing component PC has the heat resistant temperature which has the upper bound higher than 240° C. or higher than 250° C., but not limited thereto. Note that “the operation of the sound producing component PC” described in the present invention represents that the sound producing component PC can normally generate the acoustic wave. 
     Regarding the sound producing component PC, as shown in  FIG. 1  and  FIG. 2 , the sound producing component PC includes a base  110 , at least one membrane  120 , an anchor structure  130 , an actuator  140  and a cap  160 . The base  110  may containing conductive material (such as metal), such that the sound producing component PC may be electrically connected to another component to receive signals (e.g., the driving signal) from this another component and/or provide signals for another component. The base  110  may include silicon, germanium, glass, plastic, quartz, sapphire, metal, polymer, any other suitable material or a combination thereof. In this embodiment, the base  110  may be a circuit board including a laminate (e.g. copper clad laminate, CCL) or any other suitable board containing conductive material, but not limited thereto. For example, the base  110  shown in  FIG. 1  may be a circuit board and include a base body  112 , a lower conductive layer  114   a , a upper conductive layer  114   b , a lower cover layer  116   a  and a upper cover layer  116   b , wherein the base body  112  is between the lower conductive layer  114   a  and the upper conductive layer  114   b , and the base body  112 , the lower conductive layer  114   a  and the upper conductive layer  114   b  are between the lower cover layer  116   a  and the upper cover layer  116   b , but not limited thereto. In addition, in  FIG. 1 , the lower cover layer  116   a  may expose (or not cover) a portion of the lower conductive layer  114   a  to form at least one base conductive pad  114   ap.    
     The membrane  120  and the anchor structure  130  are disposed on the base  110 , and the anchor structure  130  is connected to outer edge(s) of the membrane  120 , wherein the membrane  120  is configured to be actuated to have a movement based on driving signal(s) correspondingly generated according to the input audio signal, the acoustic wave is produced due to the movement of the membrane  120 , and the outer edge(s) of the membrane  120  may define a boundary of the membrane  120 . Note that the anchor structure  130  may be a fixed end (or fixed edge) respecting the membrane  120  during the operation of the sound producing component PC. In other words, the anchor structure  130  is immobilized during the operation of the sound producing component PC. The present invention can use any suitable method to make the membrane  120  be disposed on the base  110 . For example, in  FIG. 1 , at least one connecting structure  150  is disposed between the base  110  and the anchor structure  130  for adhering to the base  110  and the anchor structure  130 , so as to make the membrane  120  and the anchor structure  130  be disposed on the base  110 , but not limited thereto. In some embodiments, the connecting structure  150  is conductive and in contact with an upper conductive pad  114   bp  of the upper conductive layer  114   b  exposed by the upper cover layer  116   b , but not limited thereto. In some embodiments, the connecting structure  150  is not conductive and disposed at any suitable position, but not limited thereto. 
     Since the surface mount technology is performed in the present invention, the membrane  120  needs to be designed for being capable of tolerating the highest process temperature of the surface mount technology. In some embodiments, the membrane  120  may include silicon (e.g., single crystalline silicon or poly-crystalline silicon), silicon compound (e.g., silicon carbide), germanium, germanium compound (e.g., gallium nitride or gallium arsenide), gallium, gallium compound, any other suitable material or a combination thereof, but not limited thereto. Furthermore, in some embodiments, the material of the anchor structure  130  may be the same as the material of the membrane  120 , but not limited thereto. In some embodiments, the material of the anchor structure  130  may include the material of the membrane  120  and any other suitable material, but not limited thereto. 
     In addition, the top-view shape of the membrane  120  may be such as a rectangle, a circle, a polygon or any other suitable shape (in  FIG. 2 , the membrane  120  is a rectangle for instance), but not limited thereto. Moreover, the membrane  120  may optionally include at least one opening (not shown in figures), wherein the opening may be a slit, a through hole or any other suitable opening, but not limited thereto. The arrangement of the opening(s) may be designed based on requirement(s). In some embodiments, the arrangement of the opening(s) may be similar to the arrangement in U.S. application Ser. No. 16/920,384 (which is not narrated herein for brevity), but not limited thereto. Note that, if the membrane  120  has the opening(s), the size of the opening(s) (e.g., a width of the slit and/or a diameter of through hole) needs to be small to prevent sound pressure level (SPL) of the acoustic wave from dropping very much. 
     In  FIG. 1  and  FIG. 2 , the sound producing component PC may have a plurality of membranes  120  (e.g.,  FIG. 2  shows six membranes  120 ), but not limited thereto. For example, in  FIG. 2 , the six membranes  120  may include a first membrane  120   a , a second membrane  120   b , a third membrane  120   c , a fourth membrane  120   d , a fifth membrane  120   e  and a sixth membrane  120   f , wherein the first membrane  120   a  and the second membrane  120   b  are arranged along a first direction D 1 , the first membrane  120   a , the third membrane  120   c  and the fifth membrane  120   e  are arranged along a second direction D 2 , and the second membrane  120   b , the fourth membrane  120   d  and the sixth membrane  120   f  are arranged along the second direction D 2 , but not limited thereto. In some embodiments, the sound producing component PC may have only one membrane  120 , but not limited thereto. 
     The actuator  140  is disposed on the membrane  120  and configured to actuate the membrane  120  to move based on the received driving signal(s). For instance, in  FIG. 1 , the actuator  140  may be in contact with the membrane  120 , but not limited thereto. In addition, the actuator  140  may have a high linear electromechanical converting function. In some embodiments, the actuator  140  may include a piezoelectric actuator, a nanoscopic-electrostatic-drive (NED) actuator or any other suitable type actuator, but not limited thereto. For example, in an embodiment, the actuator  140  may include a piezoelectric actuator, the piezoelectric actuator may contain such as two electrodes and a piezoelectric material layer disposed between the electrodes, wherein the piezoelectric material layer may actuate the membrane  120  based on the driving voltages (i.e. the driving signals) received by the electrodes, but not limited thereto. For example, in another embodiment, the actuator  140  may include a NED actuator, wherein the NED actuator may actuate the membrane  120  based on a received driving voltage (i.e. the driving signal) and an electrostatic field (i.e. the membrane  120  may be actuated by the electrostatic force), but not limited thereto. The type and disposition of the actuator  140  may be designed based on requirement(s). Note that since the anchor structure  130  may be the fixed end (or fixed edge) respecting the membrane  120  during the operation of the sound producing component PC (the anchor structure  130  is immobilizing), the anchor structure  130  need not be actuated by the actuator  140  when the actuator  140  actuates the membrane  120 . 
     Furthermore, the actuator  140  may be electrically connected to the conductive layer (e.g., the upper conductive layer  114   b ) of the base  110 , such that the driving signal(s) may be transmitted to the actuator  140 , so as to actuate the membrane  120  for producing the acoustic wave. As an example (as shown in  FIG. 1 ), if the connecting structure  150  is conductive and in contact with the upper conductive pad  114   bp  of the upper conductive layer  114   b , the actuator  140  may be electrically connected to the upper conductive layer  114   b  of the base  110  through the connecting structure  150 , but not limited thereto. As another embodiment, if the connecting structure  150  is not conductive, the actuator  140  may be electrically connected to the conductive layer of the base  110  through another component, but not limited thereto. 
     The disposition of the actuator  140  may be designed based on requirement(s). The actuator  140  may overlap the partial membrane  120  or the complete membrane  120 . For example, in  FIG. 1 , the actuator  140  may optionally overlap the partial membrane  120 , and the actuator  140  may be close to the outer edge(s) of the membrane  120 , but not limited thereto. For example, in some embodiments, the arrangement of the actuator  140  may be similar to the arrangement in U.S. application Ser. No. 16/920,384 (which is not narrated herein for brevity), but not limited thereto. 
     In particular, in some embodiments, the membrane(s)  120 , the anchor structure  130  and the actuator  140  may be components in a chip. Namely, in some embodiments, the sound producing component PC may include a chip disposed on the base  110 , and the chip includes the membrane(s)  120 , the anchor structure  130  and the actuator  140 . Specifically, the chip is formed by any suitable manufacturing process. In this embodiment, the chip may be formed by at least one semiconductor process, wherein the semiconductor process(es) may be performed on a wafer to form the chip, and the wafer may contain silicon (e.g., single crystalline silicon or poly-crystalline silicon), silicon compound (e.g., silicon carbide), germanium, germanium compound (e.g., gallium nitride or gallium arsenide), gallium, gallium compound, any other suitable material or a combination thereof. For example, the wafer may be a silicon wafer, a silicon on insulator (SOI) wafer, a polysilicon on insulator (POI) wafer, an epitaxial silicon on insulator wafer, or a germanium on insulator (GOI) wafer, but not limited thereto. Moreover, since the membrane(s)  120  may be formed by the semiconductor process(es), the chip may be a micro electro mechanical system (MEMS) structure, but not limited thereto. For example, an etching process may be performed on the chip to release the membrane  120  and form the anchor structure  130 , but not limited thereto. More precisely, if the chip is the MEMS structure, the sound producing component PC may be a package structure of the MEMS structure (i.e., the chip), but not limited thereto. Therefore, due to the semiconductor process, the size of the chip (i.e., thickness and/or the lateral dimension) may be decreased. Note that, in the present invention, the chip is the MEMS structure capable of tolerating the highest process temperature of the surface mount technology. 
     The cap  160  is disposed on the base  110 , and the membrane  120 , the actuator  140  and the cap  160  are on a same side of the base  110 , wherein the membrane  120  and the actuator  140  are situated inside the cap  160  (i.e., the membrane  120  and the actuator  140  are situated between the base  110  and the cap  160 ), such that the cap  160  can protect the membrane  120  and the actuator  140 . In addition, the cap  160  may include any suitable material, such as metal, glass, silicon, germanium, plastic and/or polymer, but not limited thereto. In an embodiment, the cap  160  may be adhered to/on the base  110  by using the surface mount technology. In this case, the cap  160  also needs to be capable of tolerating the highest process temperature of the surface mount technology. 
     Moreover, the cap  160  has at least one cap opening  160   a , and the cap opening  160   a  may be any suitable shape, such that the acoustic wave may outwards propagate from the cap opening  160   a  of the sound producing component PC. As an example, the cap  160  shown in  FIG. 1  may include one cap opening  160   a , but not limited thereto. As another example, the cap  160  may include a plurality of cap openings  160   a . In addition, the sound producing component PC may optionally include a mesh  170  disposed on the cap  160  and covering every cap opening  160   a , such that it is hard for the dust, particles and/or liquid to enter the sound producing component PC through the cap opening(s)  160   a . In some embodiments, the mesh  170  may reduce the liquid infiltration due to the design of the surface tension, but the reducing method of the liquid infiltration is not limited thereto. Furthermore, since the mesh  170  has a plurality of pores (e.g., the pore size as small as tens micrometer is typical to prevent the penetration of the dust, particles and/or liquid), such that the generated acoustic wave still propagates outwards through the mesh  170 . In an embodiment, the mesh  170  may include any suitable material which is easy to be patterned and/or to be connected to other structure (i.e., the cap  160 ), such as metal, glass, semiconductor material (e.g., silicon and/or germanium), plastic, fabric, polymer or any combination thereof, but not limited thereto. For example, the mesh  170  may be made of polyester monofilament fibers, and the polyester monofilament fibers are woven with uniform pore size thereby creating consistent acoustic resistance. Note that the mesh  170  may also need to be capable of tolerating the highest process temperature of the surface mount technology. 
     Regarding the operation of the sound producing component PC, the actuator  140  receives the driving signal to correspondingly actuate the membrane  120  to have the membrane  120  move upwardly movement or downwardly, such that the acoustic wave is produced due to the movement of the membrane  120 . Note that, in the present invention, the terms “upwardly” and “downwardly” are substantially along a direction parallel to a normal direction Dn of the membrane  120 , and the terms “upwardly” and “downwardly” are based on the  FIG. 1 . In some embodiments, the driving signal is corresponding to a sampled value of the input audio signal or a difference between two adjacent sampled values of the input audio signal, wherein the sampled value of the input audio signal represents an instantaneous value of the input audio signal sampled at a sampling time instant. In some embodiments, the acoustic wave, the input audio signal and the driving signal have the same frequency or the same frequency bandwidth, but not limited thereto. Alternatively, in some embodiments, the driving signals may make the membrane  120  generate a plurality of air pulses, each air pulse has a pulse cycle less than a cycle of the acoustic wave and a cycle of the input audio signal, and one wave of the acoustic wave is reproduced by a plurality of air pulses, wherein the pulse cycle of the air pulse is an inverse/reciprocal of a pulse rate of the air pulses, and the cycle of the acoustic wave and the cycle of the input audio signal are inverses/reciprocals of the frequency of the acoustic wave and the frequency of the input audio signal respectively. In this case, if the lengths of the pulse cycles of the air pulses are the same, the number of the air pulses reproducing one wave of the acoustic wave is decreased as the audio frequency of the acoustic wave is increased. Furthermore, in some embodiments, in order to make one wave of the acoustic wave be reproduced by the air pulse with the sufficient number, the pulse rate of the air pulses is higher than a maximum human audible frequency or higher than twice of the maximum human audible frequency (the maximum human audible frequency is generally considered to be 20 kHz), but not limited thereto. Furthermore, in some embodiments, according to Nyquist law, in order to avoid frequency spectral aliasing, the pulse rate of the air pulses needs to be at least twice higher than the maximum frequency of the acoustic wave. 
     As shown in  FIG. 1 , the sound producing component PC may have a first chamber CH 1  and a second chamber CH 2  separated by the membrane  120 , wherein the first chamber CH 1  exists between the membrane  120  and the cap  160 , and the second chamber CH 2  exists between the membrane  120  and the base  110 . In particular, the first chamber CH 1  and the second chamber CH 2  need to be connected to an ambient environment outside the sound producing component PC to advantage the actuation of the membrane  120  and the generation of the acoustic wave. In  FIG. 1  and  FIG. 3 , the first chamber CH 1  may be connected to the ambient environment outside the sound producing component PC through the cap opening  160   a  of the cap  160 . In  FIG. 1  and  FIG. 3 , the base  110  may have at least one base opening  110   a  connected to the second chamber CH 2 , the base opening  110   a  may be any suitable shape, and the second chamber CH 2  is connected to the ambient environment outside the sound producing component PC through the base opening  110   a  of the base  110 . Note that the first chamber CH 1  is connected to the front ambient environment of the sound producing component PC, and the second chamber CH 2  is connected to the back ambient environment of the sound producing component PC. 
     In some embodiments, the first chamber CH 1  and the second chamber CH 2  may need to be isolated well, so as to decrease the SPL drop of the acoustic wave due to the leak of the air between the first chamber CH 1  and the second chamber CH 2 . Thus, in the sound producing component PC, the membrane  120  of this embodiment may cover (or overlap) each base opening  110   a  in top view, wherein a top view direction may be parallel to a normal direction of the substrate SB, a normal direction of the base  110  and/or a normal direction Dn of the membrane  120  (as shown in  FIG. 1  and  FIG. 3 ). In this embodiment, as shown in  FIG. 1  and  FIG. 3 , the normal direction of the substrate SB, the normal direction of the base  110  and the normal direction Dn of the membrane  120  may be optionally parallel to each other, but not limited thereto. In  FIG. 1 , the base opening  110   a  is inside the anchor structure  130  in the top view, such that the first chamber CH 1  and the second chamber CH 2  may be substantially isolated by the membrane  120  and the anchor structure  130 . 
     Each membrane  120  may correspond to one base opening  110   a  or a plurality of base openings  110   a , and the number of the base opening(s)  110   a  corresponding to one membrane  120  may be the same or different from the number of the base opening(s)  110   a  corresponding to another membrane  120 . More precisely, in  FIG. 2 , in the top view, the base openings  110   a  may include at least one first base opening  110   a _ 1  corresponding to the first membrane  120   a , at least one second base opening  110   a _ 2  corresponding to the second membrane  120   b , at least one third base opening  110   a _ 3  corresponding to the third membrane  120   c , at least one fourth base opening  110   a _ 4  corresponding to the fourth membrane  120   d , at least one fifth base opening  110   a _ 5  corresponding to the fifth membrane  120   e  and at least one sixth base opening  110   a _ 6  corresponding to the sixth membrane  120   f  For example, in  FIG. 1  and  FIG. 2 , each membrane  120  may correspond to one base opening  110   a , but not limited thereto. Moreover, in the base opening(s)  110   a  corresponding to one membrane  120 , one of the base opening(s)  110   a  is corresponding to a center of this membrane  120  in the top view, and/or a center of a smallest region containing every base opening  110   a  corresponds to the center of this membrane  120  in the top view, wherein the smallest region may be any other suitable shape, such as a triangle, a rectangle, a polygon, a circle or a shape having a curved edge. For example, in  FIG. 1  and  FIG. 2 , since one membrane  120  corresponds to only one base opening  110   a , this base opening  110   a  is corresponding to the center of this membrane  120  in the top view, but not limited thereto. In another aspect, in  FIG. 1  and  FIG. 2 , since one membrane  120  corresponds to only one base opening  110   a , the smallest region containing this base opening  110   a  may be a region of which the boundary is the same as the edge of base opening  110   a , and the center of this smallest region may correspond to the center of this membrane  120 , but not limited thereto. In some embodiments, the base opening  110   a  may correspond to any suitable position of the membrane  120  based on requirement(s). Moreover, the base opening  110   a  may be adjusted to any suitable size based on requirement(s). In some embodiments, in order to prevent the dust, particles and/or liquid from entering the sound producing component PC through the base opening  110   a , each base opening  110   a  may have a diameter between 250˜350 μm or less than 500 μm, but not limited thereto. 
     As shown in  FIG. 1  and  FIG. 3 , the sound producing component PC is disposed on the substrate SB by the surface mount technology. Regarding the substrate SB, the substrate SB may be rigid or flexible, and include silicon, germanium, glass, plastic, quartz, sapphire, metal, polymer (e.g., polyimide (PI) or polyethylene terephthalate (PET)), any other suitable material or a combination thereof, but not limited thereto. In this embodiment, the substrate SB may be a circuit board including a laminate (e.g. copper clad laminate) or any other suitable board containing conductive material, but not limited thereto. For example, the substrate SB may be a rigid circuit board or a flexible circuit board (e.g., the substrate SB in  FIG. 3  may be a rigid circuit board), but not limited thereto. In  FIG. 3 , the substrate SB may have at least one substrate conductive pad SBp formed of the conductive material in the substrate SB, and the electronic component (e.g., the sound producing component PC) may be disposed on and connected to the substrate conductive pad SBp by the surface mount technology. 
     The surface mount technology may use the conductive adhesive layer CAL to adhere to the sound producing component PC and the substrate SB. In detail, the conductive adhesive layer CAL includes at least one conductive structure CCS, the sound producing component PC is electrically connected to the substrate conductive pad SBp of the substrate SB through the conductive structure CCS, and each conductive structure CCS is directly in contact with the sound producing component PC and one substrate conductive pad SBp. More precisely, each conductive structure CCS is directly in contact with one base conductive pad  114   ap  of the sound producing component PC and one substrate conductive pad SBp of the substrate SB. That is to say, each conductive structure CCS is between one base conductive pad  114   ap  and one substrate conductive pad SBp. In addition, the conductive adhesive layer CAL may include any suitable conductive material which can be used in the surface mount technology. For example, the conductive adhesive layer CAL may include a solder material, but not limited thereto. 
     The surface mount technology used in the method for packaging the sound producing package structure PAS will be described in the following, and the following surface mount technology is an example, and some steps are omits for making the description of the surface mount technology clear. 
     In the process of the surface mount technology, the substrate SB having the substrate conductive pad(s) SBp and the substrate opening(s) SBa may be provided firstly, wherein the substrate conductive pad(s) SBp and the substrate opening(s) SBa may be formed before performing the surface mount technology. In some embodiments, the substrate SB may further have at least one conductive trace. Then, the conductive adhesive layer CAL having the conductive structure(s) CCS is disposed on substrate conductive pad(s) SBp of the substrate SB. For example, the conductive adhesive layer CAL may be printed on the substrate SB, but not limited thereto. Next, the electronic component such as the sound producing component PC is put on the conductive adhesive layer CAL to be in contact with the conductive structure CCS, wherein the base conductive pad  114   ap  of the sound producing component PC is in contact with the conductive structure CCS. Namely, the sound producing component PC is formed before the sound producing component PC is put on the conductive adhesive layer CAL (e.g., the sound producing component PC is formed before the surface mount technology is performed). In the formation of the sound producing component PC, the base opening(s)  110   a  is formed (e.g., by an etching process), the membrane  120 , the anchor structure  130  and the actuator  140  are formed on the base  110 , and the cap  160  is formed on the base  110  (e.g., the cap  160  is adhered on the base  110 ). Then, a temperature increasing step (e.g., a reflow step) is performed to make the process temperature increase, such that the conductive structure CCS of the conductive adhesive layer CAL melt to adhere to the substrate conductive pad SBp of the substrate SB and the base conductive pad  114   ap  of the sound producing component PC. As the result, by using the surface mount technology, the sound producing component PC is disposed on the substrate SB and electrically connected to the substrate conductive pad SBp through the conductive structure CCS of the conductive adhesive layer CAL. 
     In conventional speakers or conventional sound producing devices, since some components (such as a rubber suspension and/or an adhesive material adhere to a coil) cannot tolerate the highest process temperature of the surface mount technology, the surface mount technology cannot be used in the conventional speakers (or conventional sound producing devices). In comparison, in the present invention, since the sound producing component PC is designed to be capable of tolerating the highest process temperature of the surface mount technology, the breakdown of the sound producing component PC would not occur and the sound producing component PC can normally operate after performing the surface mount technology. Moreover, since the surface mount technology is applied in the present invention, there is no need to perform a wire bonding method/process (a method/process using a conductive wire for being electrically connected between the electronic component and the substrate SB), such that the lateral size of the sound producing package structure PAS may be reduced significantly. 
     Moreover, the sound producing package structure PAS may include an outer casing OC, and the substrate SB, the sound producing component PC and the conductive adhesive layer CAL are disposed inside the outer casing OC. Optionally, the outer casing OC of this embodiment may clamp the substrate SB and the sound producing component PC (e.g., the outer casing OC may be in contact with the sidewalls of the substrate SB and the sidewalls of the sound producing component PC), so as to further fix the substrate SB and the sound producing component PC, but not limited thereto. In addition, the outer casing OC may have at least one outlet opening OCa, the outlet opening OCa may be any suitable shape, and the acoustic wave generated by the sound producing component PC may propagate through the outlet opening OCa. As shown in  FIG. 3 , the first chamber CH 1  is connected to an ambient environment outside the sound producing package structure PAS through the cap opening  160   a  of the cap  160  and the outlet opening OCa of the outer casing OC (i.e., the first chamber CH 1  is connected to a front ambient environment of the sound producing package structure PAS through the outlet opening OCa). For example, in  FIG. 3 , the outer casing OC may optionally correspond to the cap opening  160   a  of the cap  160  in the top view, but not limited thereto. For example, optionally, the outer casing OC may not overlap the cap opening  160   a  of the cap  160  in the top view, but not limited thereto. 
     Furthermore, as shown in  FIG. 3 , the substrate SB may have at least one substrate opening SBa, the substrate opening SBa may be any suitable shape, and the second chamber CH 2  is connected to the substrate opening SBa of the substrate SB through the base opening  110   a  of the base  110 . That is to say, the second chamber CH 2  is connected to an ambient environment back of the substrate SB through the base opening  110   a  and the substrate opening SBa. 
     As mentioned earlier, the first chamber CH 1  and the second chamber CH 2  needs to be isolated well, so as to decrease the SPL drop of the acoustic wave due to the leak of the air between the first chamber CH 1  and the second chamber CH 2  (for example, some air may leak from the first chamber CH 1  to the second chamber CH 2  through a small gap between the sidewalls of the substrate SB and the outer casing OC). Thus, as shown in  FIG. 3 , the sound producing component PC may cover (or overlap) each substrate opening SBa in the top view/perspective, such that the second chamber CH 2  may be not only isolated from the first chamber CH 1  well but also connected to the ambient environment back of the substrate SB smoothly. For example, the substrate opening SBa is situated inside the anchor structure  130  of the sound producing component PC in the top view. Optionally, the conductive adhesive layer CAL may further include at least one enclosing ring structure ER directly in contact with the substrate SB and the base  110 , and each enclosing ring structure ER has an enclosing pattern in the bottom view. For example, the enclosing pattern may be a rectangle, a circle, a polygon or any other suitable shape (e.g., in  FIG. 4 , the enclosing pattern may be a rectangle include rounded corners), but not limited thereto. In this embodiment, the enclosing ring structure ER is in contact with an base enclosing part  114   ae  of the lower conductive layer  114   a  not covered by the lower cover layer  116   a  and in contact with an substrate enclosing part SBe of the substrate SB, wherein the patterns of the base enclosing part  114   ae  and the substrate enclosing part SBe are the same as the enclosing pattern of the enclosing ring structure ER, but not limited thereto. In  FIG. 3  and  FIG. 4 , each substrate opening SBa of the substrate SB is inside the enclosing ring structure(s) ER in the top view (i.e., each substrate opening SBa is surrounded by one of the enclosing ring structure(s) ER). In some embodiments, each base opening  110   a  of the base  110  and each substrate opening SBa of the substrate SB are inside the enclosing ring structure(s) ER in the top view, such that the isolation between the first chamber CH 1  and the second chamber CH 2  may be improved. For example, in  FIG. 3  and  FIG. 4 , the conductive adhesive layer CAL may include only one enclosing ring structure ER, and each base opening  110   a  of the base  110  and each substrate opening SBa of the substrate SB are surrounded by this enclosing ring structure ER in the bottom view, but not limited thereto. For example, the conductive adhesive layer CAL may include a plurality of enclosing ring structures ER, and one enclosing ring structure ER may be surrounded by another enclosing ring structure ER, but not limited thereto. Furthermore, the arranged relation between the substrate conductive pad SBp and the enclosing ring structure ER may be designed based on requirement(s). For example, the substrate conductive pad SBp may be or not be surrounded by the enclosing ring structure ER. Note that, since the enclosing ring structure ER is belong to the conductive adhesive layer CAL, the enclosing ring structure ER is formed when the conductive adhesive layer CAL is formed. 
     The sound producing package structure and the method for packaging the sound producing package structure of the present invention is not limited by the above embodiments. Other embodiments of the present invention are described below. For ease of comparison, same components will be labeled with the same symbol in the following. The following descriptions relate the differences between each of the embodiments, and repeated parts will not be redundantly described. 
     Referring to  FIG. 5 ,  FIG. 5  is a schematic diagram of a bottom view illustrating a relation of substrate conductive pads, a substrate opening, an enclosing ring structure, base openings and membranes according to a second embodiment of the present invention, wherein boundaries of the membranes  120  and boundaries of the base openings  110   a  are shown by the dash lines. As shown in  FIG. 5 , a difference between this embodiment and the first embodiment is that the arrangement of the base opening  110   a  of the sound producing component PC in the sound producing package structure PAS of this embodiment. In this embodiment, each membrane  120  may be corresponding to a plurality of base openings  110   a . In detail, as shown in  FIG. 5 , the base openings  110   a  may include a plurality of first base openings  110   a _ 1  and a plurality of second base openings  110   a _ 2 . The first base openings  110   a _ 1  are corresponding to the first membrane  120   a  in the top view, and the second base openings  110   a _ 2  are corresponding to the second membrane  120   b  in the top view. The arrangement of the first base openings  110   a _ 1  and the arrangement of the second base openings  110   a _ 2  may be designed based on requirement(s). For instance, in  FIG. 5 , a center of a smallest region containing all of the first base openings  110   a _ 1  corresponds to a center of the first membrane  120   a  in the top view, and a center of a smallest region containing all of the second base openings  110   a _ 2  corresponds to a center of the second membrane  120   b , but not limited thereto. For instance, in some embodiments, one of the first base openings  110   a _ 1  corresponds to the center of the first membrane  120   a  in the top view, and one of the second base openings  110   a _ 2  corresponds to the center of the second membrane  120   b , but not limited thereto. Optionally, in  FIG. 5 , the first base openings  110   a _ 1  may be arranged in a first array, and the second base openings  110   a _ 2  may be arranged in a second array, but not limited thereto. Similarly, the base openings  110   a  may further include a plurality of third base openings  110   a _ 3  corresponding to the third membrane  120   c , a plurality of fourth base openings  110   a _ 4  corresponding to the fourth membrane  120   d , a plurality of fifth base openings  110   a _ 5  corresponding to the fifth membrane  120   e  and a plurality of sixth base openings  110   a _ 6  corresponding to the sixth membrane  120   f . In  FIG. 5 , the third base openings  110   a _ 3 , the fourth base openings  110   a _ 4 , the fifth base openings  110   a _ 5  and the sixth base openings  110   a _ 6  are respectively arranged in four arrays, but not limited thereto. 
     In particular, in order to reduce the resonance phenomenon occurring in the sound producing package structure PAS (e.g., the base  110 ) when the sound producing package structure PAS (or the sound producing component PC) operates to generate the acoustic wave, the arrangement of the first base openings  110   a _ 1  may not be completely the same as the arrangement of the second base openings  110   a _ 2 . Optionally, in some embodiments, in the top view, a row of the first array may extend along a first row direction D 1   r , a row of the second array may extend along a second row direction D 2   r , and the first row direction D 1   r  is not parallel to the second row direction D 2   r , such that the arrangement of the first base openings  110   a _ 1  may not be the same as the arrangement of the second base openings  110   a _ 2 . For instance, in  FIG. 5 , an included angle between the first row direction D 1   r  and the first direction D 1  is about −22°, and an included angle between the second row direction D 2   r  and the first direction D 1  is about 22°, but not limited thereto. For example, the arrangement of the third base openings  110   a _ 3  may not be completely the same as the arrangement of the fourth base openings  110   a _ 4 , and the arrangement of the fifth base openings  110   a _ 5  may not be completely the same as the arrangement of the sixth base openings  110   a _ 6 , but not limited thereto. For instance, some arrangements of the base openings  110   a  may be the same (e.g., the arrangement of the fourth base openings  110   a _ 4  may be the same as the arrangement of the sixth base openings  110   a _ 6  in  FIG. 5 ), but not limited thereto. For example, the arrangement of the first base openings  110   a _ 1  may be symmetric or asymmetric to the arrangement of the second base openings  110   a _ 2  (e.g., in  FIG. 5 , the arrangement of the first base openings  110   a _ 1  is symmetric to the arrangement of the second base openings  110   a _ 2 ). 
     Optionally, if the base openings  110   a  are arranged with a special distance respecting to the side-edge of the membrane  120 , the resonance phenomenon occurring in the sound producing package structure PAS may be further reduced due to the asymmetric arrangement of the base openings  110   a . More precisely, in  FIG. 5 , the first membrane  120   a  has a first side-edge  120   a _ 1  and a second side-edge  120   a _ 2  opposite to the first side-edge  120   a _ 1 . In one of the first base openings  110   a _ 1  (or each of the first base openings  110   a _ 1 ), a first opening distance S 1  is between a center C 1  of the first base opening  110   a _ 1  and the first side-edge  120   a _ 1  of the first membrane  120   a , a second opening distance S 2  is between the center C 1  of the first base opening  110   a _ 1  and the second side-edge  120   a _ 2  of the first membrane  120   a , and a ratio of the first opening distance S 1  to the second opening distance S 2  may be the well-known golden ratio (substantially be 1.618), but not limited thereto. Moreover, in  FIG. 5 , the first membrane  120   a  has a third side-edge  120   a _ 3  and a fourth side-edge  120   a _ 4  opposite to the third side-edge  120   a _ 3 , wherein the third side-edge  120   a _ 3  and the fourth side-edge  120   a _ 4  are between the first side-edge  120   a _ 1  and the second side-edge  120   a _ 2 . In one of the first base openings  110   a _ 1  (or each of the first base openings  110   a _ 1 ), a third opening distance S 3  is between the center C 1  of the first base opening  110   a _ 1  and the third side-edge  120   a _ 3  of the first membrane  120   a , a fourth opening distance S 4  is between the center C 1  of the first base opening  110   a _ 1  and the fourth side-edge  120   a _ 4  of the first membrane  120   a , and a ratio of the third opening distance S 3  to the fourth opening distance S 4  may be the golden ratio, but not limited thereto. Similarly, the above golden ratio arrangement may be used in the arrangement of other base openings  110   a , but not limited thereto. 
     Referring to  FIG. 6 ,  FIG. 6  is a schematic diagram of a cross sectional view illustrating a sound producing package structure according to a third embodiment of the present invention. Note that, although  FIG. 6  does not show the substrate opening SBa, the substrate opening SBa exists in the third embodiment and is situated at any other suitable position. As shown in  FIG. 6 , a difference between the current embodiment and the first embodiment is that the isolating method of the first chamber CH 1  and the second chamber CH 2 . The sound producing package structure PAS of the current embodiment may include a gasket GK disposed between the sound producing component PC and the outer casing OC, and the gasket GK surrounds the outlet opening(s) OCa and the cap opening(s)  160   a . In this embodiment, owing to the disposition of the gasket GK, the air leaking from the first chamber CH 1  to the second chamber CH 2  through the small gap between the sidewalls of the substrate SB and the outer casing OC may be avoided/reduced. Thus, the first chamber CH 1  and the second chamber CH 2  may be isolated well to decrease the SPL drop of the acoustic wave. 
     In some embodiments, the sound producing package structure PAS may include the gasket GK disposed between the sound producing component PC and the outer casing OC, and the conductive adhesive layer CAL may include the enclosing ring structure(s) ER directly in contact with the substrate SB and the base  110  (the content of the enclosing ring structure(s) ER can be referred to the first embodiment). In this case, the first chamber CH 1  and the second chamber CH 2  may be isolated well to decrease the SPL drop of the acoustic wave. 
     Furthermore, in this embodiment shown in  FIG. 6 , the substrate SB may be a flexible substrate SB (e.g., the flexible circuit board), but not limited thereto. In another embodiment, the substrate SB may be a rigid substrate SB, but not limited thereto. 
     In summary, according to the present invention, the surface mount technology is used to manufacture the sound producing package structure PAS, the highly automatized formation of the sound producing package structure PAS can be achieved, and/or the sound producing package structure PAS can be miniaturized more. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.