Abstract:
The present invention provides a diaphragm structure of a sounding apparatus comprising: a thin-film layer; a first circuit thin-film layer fixed on a first side of the thin-film layer by means of a first electrolytic bonding layer; a second circuit thin-film layer fixed on a second side of the thin-film layer by means of a second electrolytic bonding layer; multiple holes passing through the first circuit thin-film layer, the thin-film layer and the second circuit thin-film layer; and multiple conductive layers disposed on inner circumferential walls of the holes and in contact with the first circuit thin-film layer and the second circuit thin-film layer. In the diaphragm structure provided by the present invention, instead of using back adhesives, electrolytic bonding is used to fix the circuit thin-film layers on two sides of a thin-film layer, thereby greatly reducing the thickness of the diaphragm structure.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention generally relates to a diaphragm structure, and particularly relates to a diaphragm structure, of which on the thin-film metal coils are fixed by electrolytic bonding, thereby the thickness of a sounding apparatus monomer is greatly reduced. 
         [0003]    2. The Prior Arts 
         [0004]    According to the differences in structures and principles of sounding, sounding apparatus can be classified into several types such as moving coil type speakers, piezoelectric speakers, piezoelectric ceramic speakers and paper speakers. Amongst the above mentioned speakers, the most common one is the conventional moving coil type speaker. The structure of the moving coil type speaker is formed by the following steps: firstly, winding an enameled coil on the outer circumference of a cylindrical tube to form a voice coil; secondly, adhering one end of the voice coil at one side of a diaphragm; lastly, disposing the diaphragm at one side of a magnet to form a moving coil type speaker monomer. When using this type of monomer for sounding, corresponding audio frequency current is passed through the enameled coil such that the magnetic field of the coil is changed by electromagnetic induction to drive the diaphragm to vibrate, thereby vibrating the air to sound. The moving coil type monomer is advantageous in having good sound quality at low and medium frequency. However, due to its large size, moving coil type speakers are not suitable for apparatuses with small volumes. Besides, since the moving coil type speaker has a greater monomer thickness, it has poorer performance at high frequency. 
         [0005]    In conventional monomer structures, voice coils are fixed onto the thin-film by ways of back adhesive. Since available adhesives in the art possess a certain thickness, such a fixing method would result in a monomer with a greater overall thickness; as a result, the overall size of a sounding apparatus, such as earphones, with such a monomer and the overall size of the earphones cannot be reduced. In addition, as the sensibility of the sounding apparatus is required to be improved, it is common to increase the magnetic flux density by increasing the number of coils. However, since the conventional fixation by back adhesive results in an overly thick thickness of the monomer after the number of the coils is increased, designs of the sounding apparatus and earphones are restricted. 
       SUMMARY OF THE INVENTION 
       [0006]    Based on the above reasons, an objective of the present invention is to provide a diaphragm structure with metal coils fixed on thin-films by ways of electrolytic bonding instead of back adhesive. In such a way, the thickness of the diaphragm is greatly reduced. 
         [0007]    Another objective of the present invention is to provide a diaphragm structure in which a plurality of metal coils and a plurality of thin-films are laminated and fixed alternately by ways of electrolytic bonding, such that the diaphragm structure may have a greater magnetic flux while the thickness remains unchanged. 
         [0008]    In order to achieve the above-mentioned objectives, the present invention provides a diaphragm structure that includes a thin-film layer, a first circuit thin-film layer, a second circuit thin-film layer and at least one conductive structure. The thin-film layer has a first side and a second side. The first circuit thin-film layer is fixed to the first side of the thin-film layer by means of a first electrolytic bonding layer and the first circuit thin-film layer has a first contact terminal at one end. The second circuit thin-film layer is fixed to the second side of the thin-film layer by means of a second electrolytic bonding layer and the second circuit thin-film layer has a second contact terminal at one end. The at least one conductive structure penetrates through the thin-film layer to connect the first circuit thin-film layer and the second circuit thin-film layer. 
         [0009]    According to an embodiment of the present invention, the conductive structure includes a perforation and a conductive layer. The perforation penetrates from an outer surface of the first circuit thin-film layer through the thin-film layer to an outer surface of the second circuit thin-film layer. The conductive layer is disposed on an inner circumferential wall of the perforation and the conductive layer is in contact with the first circuit thin-film layer and the second circuit thin-film layer simultaneously. 
         [0010]    In addition, the present invention provides another diaphragm structure that includes a thin-film layer, a first circuit thin-film layer, at least one laminated layer, a second circuit thin-film layer and a plurality of conductive structures. The thin-film layer has a first side and a second side. The first circuit thin-film layer is fixed to the first side of the thin-film layer by means of a first electrolytic bonding layer and the first circuit thin-film layer has a first contact terminal at one end. Each of the at least one laminated layer includes a third circuit thin-film layer and a laminated thin-film layer. The laminated thin-film layer is fixed to the third circuit thin-film layer by means of a laminated electrolytic bonding layer. The third circuit thin-film layer at an outermost side of the at least one laminated layer is fixed to the second side of the thin-film layer by means of a third electrolytic bonding layer. The second circuit thin-film layer is fixed to the laminated thin-film layer at another outermost side of the at least one laminated layer by means of a second electrolytic bonding layer and the second circuit thin-film layer has a second contact terminal at one end. Herein, every two adjacent circuit thin-film layers among the first circuit thin-film layer, the second circuit thin-film layer and at least one third circuit thin-film layer are connected to each other by means of at least one conductive structure. 
         [0011]    According to an embodiment of the present invention, each of the conductive structures includes a perforation and a conductive layer. The perforation penetrates from a former one of the two adjacent circuit thin-film layers through the laminated thin-film layer or the thin-film layer between the two adjacent circuit thin-film layers to a later one of the two adjacent circuit thin-film layers. The conductive layer is disposed on an inner circumferential wall of the perforation and the conductive layer is in contact with the two adjacent circuit thin-film layers. 
         [0012]    According to an embodiment of the present invention, the diaphragm structure further comprises a plurality of covering parts. The covering parts are disposed on the outer surface of the first circuit thin-film layer and on the outer surface of the second circuit thin-film layer around all of the perforations, and the covering parts are in contact with the conductive layers in the perforations. 
         [0013]    According to an embodiment of the present invention, the diaphragm structure comprises a plurality of laminated layers. Every two laminated layers are fixed with each other by means of laminated electrolytic bonding layer in between. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is an exploded diagram of the diaphragm structure according to a first embodiment of the present invention; 
           [0015]      FIG. 2  is a side sectional view of the diaphragm structure according to the first embodiment of the present invention; 
           [0016]      FIG. 3  is an exploded diagram of the diaphragm structure according to a second embodiment of the present invention; 
           [0017]      FIG. 4  is a side sectional view of the diaphragm structure according to the second embodiment of the present invention; and 
           [0018]      FIG. 5  is an exploded diagram of the diaphragm structure according to the third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    The drawings and reference symbols are incorporated hereafter to further illustrate the embodiments of the present invention so that the present invention can be implemented by a person skilled in the art. 
         [0020]      FIG. 1  is an exploded diagram of the diaphragm structure according to a first embodiment of the present invention; and  FIG. 2  is a side sectional view of the diaphragm structure according to the first embodiment of the present invention. As shown in  FIG. 1  and  FIG. 2 , the diaphragm structure provided according the first embodiment of the present invention mainly comprises a thin-film layer  11 , a first circuit thin-film layer  21 , a second circuit thin-film layer  22  and a conductive structure. 
         [0021]    The thin-film layer  11  includes a first side  111  and a second side  112 . In the present invention, non-adhesive copper is used as the first circuit thin-film layer  21  and the second circuit thin-film layer  22 . The first circuit thin-film layer  21  and the second circuit thin-film layer  22  are respectively fixed to two sides of the thin-film layer  11  by ways of electrolytic bonding to form a diaphragm of a sounding apparatus such as earphones. As shown in  FIG. 2 , the first circuit thin-film layer  21  and the second circuit thin-film layer  22  have a first contact terminal  211  and a second contact terminal  221  respectively. The first circuit thin-film layer  21  is fixed to the first side  111  of the thin-film layer  11  via a first electrolytic bonding layer  41  by ways of electrolytic bonding, and the second circuit thin-film layer  22  is fixed to the second side  112  of the thin-film layer  11  via a second electrolytic bonding layer  42  by ways of electrolytic bonding. Please be advised that, for clarity, the thickness of the electrolytic bonding layers is not depicted in accordance with the actual scale. The actual thickness of the electrolytic bonding layers is thinner than shown in the figures. In addition, the material of the circuit thin-film layer is not limited to non-adhesive copper; any materials that are conductive and can be fixed on the thin-film layer by electrolytic bonding are suitable. 
         [0022]    A plurality of holes  110 ,  210 , and  220  are formed respectively on the thin-film layer  11 , the first circuit thin-film layer  21  and the second circuit thin-film  22 , such that perforations  5  which penetrate the diaphragm can be formed when the first circuit thin-film layer  21  and the second circuit thin-film  22  are fixed to two sides of the thin-film layer  11 . As shown in  FIG. 1 , since four holes are formed on the thin-film layer  11 , the first circuit thin-film layer  21  and the second circuit thin-film  22 , the diaphragm of the present invention has a total of four perforations  5 . When sounding, it is required to conduct current through the first circuit thin-film layer  21  and the second thin-film layer  22  so that the magnetic field is changed and the thin-film layer  11  is driven to vibrate the air for sounding. Thus, the inner circumferential wall of the perforations  5  is plated with a layer of conductive layer  51  by ways of selective plating to electrically connect the first circuit thin-film layer  21  and the second thin-film layer  22  with each other. As shown in  FIG. 2 , a covering part  52  is formed on the outer surface of the first circuit thin-film layer  21  and on the outer surface of the second thin-film layer  22  at the periphery of each of the perforations  5 . The covering parts  52  are in contact with the conductive layers  51  to further ensure the electrical connection between the first circuit thin-film layer  21  and the second thin-film layer  22 . 
         [0023]    The diaphragm structure provided by the first embodiment of the present invention allows the overall thickness of the diaphragm structure to be greatly reduced by fixing the first circuit thin-film layer  21  and the second thin-film layer  22 , which are composed of non-adhesive copper, to two sides of the thin-film layer  11  by electrolytic bonding; in addition, the overall thickness is also reduced by forming the conductive layers  51  in the perforations  5  by selective plating. More precisely, comparing to the conventional diaphragms, of which the metal coils are fixed to the thin-film by means of back adhesive, the diaphragm structure provided by the present invention allows the thickness of the diaphragm to be reduced from 8.75 μm to 4 μm. In this way, the dimension of the monomer of the sounding apparatus and the dimension of the sounding apparatus itself are greatly reduced. As a result, the diaphragm structure provided by the present invention is applicable to sounding apparatuses in small dimension, such as earphones. 
         [0024]    The magnetic flux of the earphones greatly affects their sensibility of the earphones. Earphones with high magnetic flux are capable of producing louder sounds with small power. Under the condition of not increasing the plane area of the diaphragm of the earphones, it is common to increase the magnetic flux by laminating a number of metal coils. Yet, when using conventional back adhesive for ways of fixing, the overall thickness of the diaphragm may become too thick. In order to address the problem, another diaphragm structure is provided by the second and third embodiment of the present invention. 
         [0025]      FIG. 3  is an exploded diagram of the diaphragm structure according to the second embodiment of the present invention; and  FIG. 4  is a side sectional view of the diaphragm structure according to the second embodiment of the present invention. As shown in  FIG. 3  and  FIG. 4 , the diaphragm structure according to the second embodiment of the present invention, similar to that according to the first embodiment, includes a thin-film layer  11 , a first circuit thin-film layer  21  and a second circuit thin-film layer  22 . The diaphragm structure according to the second embodiment and that according to the first embodiment are different in that a laminated layer  23  is further disposed on the diaphragm structure of the second embodiment. 
         [0026]    Similar to the first embodiment, the thin-film layer  11  of the second embodiment has a first side  111  and a second side  112 . The first circuit thin-film layer  21  and the second circuit thin-film layer  22  have a first contact terminal  211  and a second contact terminal  221  respectively, and are comprised of non-adhesive copper. The first circuit thin-film layer  21  is fixed to the first side  111  of the thin-film layer  11  via the first electrolytic bonding layer  41  by ways of electrolytic bonding. The laminated layer  23  of the second embodiment is composed of a third circuit thin-film layer  3  and a laminated thin-film layer  12 . The third circuit thin-film layer  3  is fixed to the laminated layer  12  via a laminated electrolytic bonding layer  44  by ways of electrolytic bonding. As shown in  FIG. 4 , the third circuit thin-film layer  3  of the laminated layer  23  is fixed to the second side  112  of the thin-film layer  11  via the third electrolytic bonding layer  43  by ways of electrolytic bonding, and the second circuit thin-layer film  22  is fixed to the laminated thin-film layer  12  of the laminated layer  23  via the second electrolytic bonding layer  42  by ways of electrolytic bonding. 
         [0027]    In the diaphragm structure provided by the present invention, every two adjacent circuit thin-film layers are connected to each other by means of at least one conductive structure. More specifically, as shown in  FIG. 3 , holes  210 ,  110  and  30   a  are disposed on the first circuit thin-film layer  21 , the thin-film layer  11  and the third circuit thin-film layer  3  respectively, and holes  30   b,    120  and  220  are disposed on the third circuit thin-film layer  3 , the laminated thin-film layer  12  and the second circuit thin-film layer  22  respectively. As shown in  FIG. 4 , after the diaphragm structure is fixed as mentioned above, the holes  210 ,  110 , and  30   a  form perforations  5   a;  and the holes  30   b,    120  and  220  form perforations  5   b.  The perforations  5   a  and the perforations  5   b  are plated with a layer of conductive layer  51  by ways of selective plating. The conductive layer  51  in the perforations  5   a  electrically connects the first circuit thin-film layer  21  and the third circuit thin-film layer  3 , and the conductive layer  51  in the perforations  5   b  electrically connects the third circuit thin-film layer  3  and the second circuit thin-film layer  22 ; as a result, a circuit between the first contact terminal  211  and the second contact terminal  221  is formed. 
         [0028]    Besides, similar to the first embodiment, a covering part  52  is formed on the outer surface of the first circuit thin-film layer  21  at the periphery of each perforation  5   a,  and is also formed on the outer surface of the second circuit thin-film layer  22  at the periphery of each perforation  5   b.  The covering parts are in contact with the conductive layers  51  to further ensure the electrical connection between the first contact terminal  211  and the second contact terminal  221 . 
         [0029]    Via the diaphragm structure provided by the second embodiment, by laminating the metal coils, the magnetic flux of the diaphragm can be increased without greatly increasing the overall thickness of the diaphragm. Thus, the sensibility of the earphones is increased while the earphones monomer and earphones can be maintained in small dimension, so that the designers are provided with more options when designing earphones. 
         [0030]    The number of the laminated layers  23  in the diaphragm structure provided by the present invention is not limited to a single layer as depicted in the second embodiment.  FIG. 5  shows an exploded diagram of the diaphragm structure according to the third embodiment of the present invention. As shown in  FIG. 5 , the diaphragm structure in the third embodiment is nearly the same as that in the second embodiment; they are different only in the number of the laminated layers  23 . 
         [0031]    In the third embodiment, the diaphragm structure has a number of N laminated layers  23 . Between every two adjacent laminated layers  23 , the third circuit thin-film  3  and the laminated thin-film layer  12  adjacent are fixed with each other via the electrolytic bonding layer  44  by ways of electrolytic bonding (not shown in  FIG. 5 ). Besides, among a number of N laminated layers  23  that are laminated with each other, the third circuit thin-layer  3  at the outermost side is fixed to the second side  112  of the thin-film layer  11  via the laminated electrolytic bonding layer  44  by ways of electrolytic bonding, and the laminated thin-layer  12  at the outermost side is fixed to the second circuit thin-film layer  22  via the second electrolytic bonding layer  42  by ways of electrolytic bonding. Among the first circuit thin-film layer  21 , the second circuit thin-film layer  22  and all of the third circuit thin-film layers  3  of the diaphragm structure of the third embodiment, a former one of every two adjacent circuit thin-film layers penetrates through the laminated thin-film layer or thin-film layer between two adjacent circuit thin-film layers via the conductive structure to connect the later one of two adjacent circuit thin-film layers. In such configuration, designers can modify the number of the laminated layers  23  according to the required magnetic flux for earphones. 
         [0032]    From the embodiments above, it is clear that the diaphragm structure provided by the present invention is valuable and usable in industries. However, the description above is provided only for explanting the preferable embodiments of the present invention, but not for limiting or restricting the present invention. Thus, any modifications or alternations to the present invention without departing from the spirit of the present invention are intended to be included within the protection scope of the present invention.