Conductive diaphragm, sound emitting unit, and electronic device
By using an embedded connection structure between the conductive adhesive layer and the diaphragm, the stress concentration problem is solved, improving the structural reliability and acoustic performance of the miniature loudspeaker and extending its service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SSI NEW MATERIAL (ZHENJIANG) CO LTD
- Filing Date
- 2025-08-04
- Publication Date
- 2026-07-28
AI Technical Summary
In existing miniature loudspeakers, the connection structure between the conductive adhesive layer and the diaphragm leads to stress concentration, resulting in diaphragm fatigue damage, cracks, and detachment of the conductive adhesive layer, affecting long-term reliability and acoustic performance.
An embedded connection structure between the conductive adhesive layer and the diaphragm is adopted. The lower surface of the middle part and the transition part of the conductive adhesive layer is a continuous curvature arc surface. Through pressing and composite molding, the depth of the conductive adhesive layer embedded in the diaphragm is within a certain proportion range to ensure a smooth transition and reduce stress concentration.
It enhances the structural reliability and durability of the conductive diaphragm under long-term vibration conditions, maintains good acoustic performance, and extends its service life.
Smart Images
Figure CN224571369U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of sound energy conversion technology, and in particular to a conductive diaphragm, a sound generating unit, and an electronic device. Background Technology
[0002] Early miniature loudspeakers used external leads for power supply, but because of the external leads, the vibration amplitude could not be too large, otherwise the leads might break due to the large amplitude.
[0003] As the amplitude increases, the structure of miniature loudspeakers also changes, such as further extending the wires and fixing them with damping adhesive. However, to meet the demand for even larger amplitudes, the drawbacks of directly leading out the wires gradually become apparent. The structure of miniature loudspeakers has been further modified, adding an FPC (flexible printed circuit board) layer to realize the electrical connection of the voice coil. This not only allows for wire conduction but also enables a wave-like effect similar to that in large loudspeakers, suppressing phenomena such as rolling vibration that are detrimental to acoustic performance, thus achieving a larger amplitude.
[0004] However, the FPC itself occupies a certain amount of space, which limits further increases in amplitude. On the other hand, installing the FPC restricts the magnet at the mounting point (usually the short axis) (it is typically shorter than magnets in other locations), which leads to a decrease in magnetic field strength and affects magnetic field uniformity, thus negatively impacting the achievement of larger amplitudes.
[0005] To address the problems caused by FPCs, the use of conductive diaphragms composed of a composite diaphragm and conductive adhesive to replace FPCs for external power supply has become a research trend. Since the diaphragm is constantly vibrating during operation, the adhesion strength and reliability between the diaphragm and the conductive adhesive have become key concerns for the industry.
[0006] In existing technologies, such as Figure 20 As shown, the diaphragm 10 typically has grooves with right angles / edges, and the conductive adhesive layer 20 is embedded in the grooves of the diaphragm 10. This structure allows the conductive adhesive layer and the diaphragm to form a relatively tight integrated structure, thereby improving the bonding strength between the conductive adhesive layer and the diaphragm to a certain extent in the initial stage. However, due to the obvious right angles / edges at the contact interface between the conductive adhesive layer and the diaphragm, the stress of the diaphragm tends to concentrate at the right angles / edges of the conductive adhesive layer and the diaphragm grooves during long-term vibration or operation. Stress concentration makes the diaphragm prone to fatigue damage and cracking at this location, affecting the acoustic performance of the diaphragm, and causing diaphragm breakage and conductive adhesive layer detachment, thus affecting the long-term reliability and service life of the conductive diaphragm. Furthermore, the grooves on the diaphragm reduce the overall uniformity of the diaphragm, thereby reducing the initial acoustic performance of the diaphragm to a certain extent, which also leads to a deterioration in the overall initial acoustic performance of the conductive diaphragm.
[0007] Therefore, it is necessary to develop a more reasonable connection structure between the conductive adhesive and the diaphragm. By reducing stress concentration and ensuring the overall initial acoustic performance of the conductive diaphragm, the bonding strength between the conductive adhesive and the diaphragm can be improved, thereby effectively enhancing the structural reliability and durability of the conductive diaphragm under long-term vibration conditions and maintaining good acoustic performance. Utility Model Content
[0008] The purpose of this invention is to provide a conductive diaphragm, a sound-generating unit, and an electronic device, which achieves external connection of the voice coil through the conductive diaphragm, thereby solving the problem of the influence of the magnetic field and the limitation of the amplitude of the existing external voice coil connection scheme.
[0009] The above-mentioned technical objectives of this utility model are mainly achieved through the following technical solutions.
[0010] In a first aspect, this utility model provides a conductive diaphragm, comprising:
[0011] A diaphragm and a conductive adhesive layer, wherein the conductive adhesive layer is embedded in the diaphragm and bonded to the diaphragm, and along the width direction of the conductive adhesive layer, the conductive adhesive layer includes a middle portion and transition portions located on both sides of the middle portion, the lower surface of the middle portion is a plane or an arc surface with continuous curvature or a combination of the above two surfaces, and the thickness of the transition portion gradually decreases along the direction away from the middle portion, and the lower surface of the transition portion is also an arc surface with continuous curvature.
[0012] In a preferred embodiment of the present invention, the conductive adhesive layer has a smooth transition with continuous curvature at the connection between the middle part and the transition part.
[0013] In a preferred embodiment of the present invention, the conductive adhesive layer protrudes from the surface of the diaphragm along its thickness direction.
[0014] In a preferred embodiment of this invention, the depth to which the conductive adhesive layer is embedded in the diaphragm accounts for 5% to 80% of the thickness of the conductive adhesive layer.
[0015] In a preferred embodiment of this invention, the depth to which the conductive adhesive layer is embedded in the diaphragm accounts for 5% to 50% of the thickness of the conductive adhesive layer.
[0016] In a preferred embodiment of this invention, the conductive adhesive layer and the diaphragm are compositely shaped by pressing.
[0017] In a preferred embodiment of the present invention, the conductive adhesive layer is embedded in the diaphragm to a depth of 5% to 70% of the diaphragm thickness.
[0018] In a preferred embodiment of the present invention, the conductive adhesive layer is embedded in the diaphragm to a depth of 5% to 40% of the diaphragm thickness.
[0019] In a preferred embodiment of the present invention, the thickness of the conductive adhesive layer is 10μm to 60μm, the width of the conductive adhesive layer is 0.1mm to 6mm, and the length of the conductive adhesive layer is 0.1mm to 6mm.
[0020] In a preferred embodiment of this utility model, the thickness of the conductive adhesive layer is 15μm to 40μm, the width of the conductive adhesive layer is 0.2mm to 5mm, and the length of the conductive adhesive layer is 0.2mm to 5mm.
[0021] In a preferred embodiment of this utility model, the thickness of the conductive adhesive layer is 20μm to 30μm, the width of the conductive adhesive layer is 0.5mm to 4mm, and the length of the conductive adhesive layer is 0.5mm to 4mm.
[0022] In a preferred embodiment of this invention, the height of the protrusion on the opposite side of the diaphragm that is attached to the conductive adhesive layer accounts for 0% to 55% of the original thickness of the diaphragm.
[0023] Secondly, this utility model also provides a sound-generating unit, which includes:
[0024] The magnetic gap formed by the magnet;
[0025] A voice coil is placed within the magnetic gap;
[0026] A conductive diaphragm is connected to the voice coil, the conductive diaphragm being the one described above, and the wires inside the voice coil are electrically connected to the conductive adhesive layer on the conductive diaphragm.
[0027] Thirdly, this utility model also provides an electronic device, which includes the sound-generating unit described above.
[0028] Compared with the prior art, the technical solution of this utility model has the following features and advantages:
[0029] The conductive diaphragm of this invention has a conductive adhesive layer embedded in the diaphragm, resulting in strong interaction force. Furthermore, the lower surface of the conductive adhesive layer in the middle and transition sections is a plane, an arc surface with continuous curvature, or a combination of both. The connection between the middle and transition sections has a smooth transition with continuous curvature, which greatly reduces or even eliminates stress concentration between the diaphragm and the conductive adhesive layer. Therefore, it enhances the structural reliability and durability of the conductive diaphragm under long-term vibration conditions.
[0030] The conductive diaphragm of this invention, as verified by experiments, exhibits a specific numerical range for the ratio of the conductive adhesive layer's embedding depth to the diaphragm's thickness and the ratio of the conductive adhesive layer's embedding depth to the diaphragm's thickness. Firstly, to better bond the conductive adhesive layer with the diaphragm, embedding it into the diaphragm enhances the bonding strength, ensuring the adhesive layer does not detach under operating conditions. Secondly, due to the difference in modulus between the conductive adhesive layer and the diaphragm, the embedding depth of the conductive adhesive layer affects the diaphragm's initial acoustic performance to a certain extent, thus influencing the overall acoustic performance of the conductive diaphragm. Therefore, maintaining a certain numerical range for the ratio of the conductive adhesive layer's embedding depth to the diaphragm thickness allows the conductive diaphragm's acoustic and mechanical properties to simultaneously meet usage requirements, thereby extending the diaphragm's lifespan. Thirdly, during the composite molding process of the conductive adhesive layer and the diaphragm, the pressure will cause the ratio of the depth of the conductive adhesive layer embedded in the diaphragm to the thickness of the conductive adhesive layer to change. At the same time, the conductive adhesive layer will undergo a certain degree of compaction and extension. Compaction will lead to a decrease in the resistivity of the conductive adhesive layer, but extension will significantly increase the resistivity of the conductive adhesive layer. Therefore, controlling the pressure to keep the ratio of the depth of the conductive adhesive layer embedded in the diaphragm to the thickness of the conductive adhesive layer within a certain range can keep the resistivity of the conductive adhesive layer unchanged and achieve a good electrical conduction effect.
[0031] The aforementioned embedding depth design can bring better acoustic and mechanical properties to the diaphragm, thereby extending the diaphragm's service life. Attached Figure Description
[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:
[0033] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, under the guidance of this invention, can select various possible shapes and proportions to implement this invention according to specific circumstances.
[0034] Figure 1 This is a schematic diagram of the first embodiment of the conductive adhesive layer distribution on the conductive diaphragm of the present invention;
[0035] Figure 2 This is a schematic diagram of a second embodiment of the distribution of the conductive adhesive layer on the conductive diaphragm of this utility model;
[0036] Figure 3 This is a schematic diagram of the distribution of the conductive adhesive layer on the conductive diaphragm of the present invention in a third embodiment;
[0037] Figure 4 This is a schematic diagram of the first embodiment of the internal structure of the conductive diaphragm of this utility model;
[0038] Figure 5 This is a schematic diagram of the second embodiment of the internal structure of the conductive diaphragm described in this utility model;
[0039] Figure 6 This is a schematic diagram of the third embodiment of the internal structure of the conductive diaphragm of this utility model;
[0040] Figure 7 This is a schematic diagram of the fourth embodiment of the internal structure of the conductive diaphragm of this utility model;
[0041] Figure 8 This is a schematic diagram of the first embodiment of the embedded structure of the diaphragm and conductive adhesive layer described in this utility model;
[0042] Figure 9 This is a schematic diagram of the second embodiment of the embedded structure of the diaphragm and conductive adhesive layer described in this utility model;
[0043] Figure 10 This is a schematic diagram of the third embodiment of the embedded structure of the diaphragm and conductive adhesive layer described in this utility model;
[0044] Figure 11 This is a schematic diagram of the fourth embodiment of the embedded structure of the diaphragm and conductive adhesive layer described in this utility model;
[0045] Figure 12 This is a schematic diagram of the fifth embodiment of the embedded structure of the diaphragm and conductive adhesive layer described in this utility model;
[0046] Figure 13 This is a first measured structural schematic diagram of the embedded structure of the diaphragm and conductive adhesive layer described in this utility model;
[0047] Figure 14 This is a schematic diagram of the second measured structure of the embedded structure of the diaphragm and conductive adhesive layer described in this utility model;
[0048] Figure 15 This is a schematic diagram of the third measured structure of the embedded structure of the diaphragm and conductive adhesive layer described in this utility model;
[0049] Figure 16 This is a schematic diagram of the fourth measured structure of the embedded structure of the diaphragm and conductive adhesive layer described in this utility model;
[0050] Figure 17 for Figures 13 to 16 The diagram shows a comparison of the sound pressure levels of the conductive diaphragm at different vibration frequencies.
[0051] Figure 18 This is a schematic diagram of the test results for the conductive diaphragm described in the utility model.
[0052] Figure 19 This is a schematic diagram of the test results for bonding the diaphragm and conductive adhesive in the prior art;
[0053] Figure 20 This is a schematic diagram of the bonding of the diaphragm and conductive adhesive in the prior art;
[0054] Figure 21 This is a schematic diagram of the third comparative example of the present invention.
[0055] Explanation of reference numerals in the attached figures:
[0056] 10. Diaphragm; 11. Diaphragm body; 12. Dome;
[0057] 20. Conductive adhesive layer; 21. Middle part; 22. Transition part. Detailed Implementation
[0058] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.
[0059] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.
[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0061] Implementation Method 1:
[0062] like Figures 1 to 13 As shown, this utility model provides a conductive diaphragm, which includes a diaphragm 10 and a conductive adhesive layer 20. The conductive adhesive layer 20 is embedded in the diaphragm 10 and is bonded to the diaphragm 10. Along the width direction of the conductive adhesive layer 20, the conductive adhesive layer 20 includes a middle portion 21 and transition portions 22 located on both sides of the middle portion 21. The lower surface of the middle portion 21 is a plane or an arc surface with continuous curvature or a combination of the above two surfaces. Along the direction away from the middle portion 21, the thickness of the transition portion 22 gradually decreases, and the lower surface of the transition portion 22 is also an arc surface with continuous curvature.
[0063] The conductive diaphragm of this invention has a conductive adhesive layer 20 embedded in the diaphragm 10, which is integrated with the diaphragm 10. This results in a stronger interaction force. During the long-term vibration of the diaphragm 10, due to the damping and protection effect of the diaphragm 10 on the conductive adhesive layer 20, there will be no adverse phenomena such as cracking of the conductive adhesive layer 20, and the acoustic performance of the diaphragm 10 will not be affected.
[0064] The conductive diaphragm of this invention has a conductive adhesive layer 20 with a plane or an arc surface with continuous curvature or a combination of the two on the lower surface of the middle part 21 and the transition part 22. This greatly reduces or even eliminates stress concentration between the diaphragm 10 and the conductive adhesive layer 20, thereby enhancing the structural reliability and durability of the conductive diaphragm under long-term vibration conditions.
[0065] The following will provide a detailed description of the specific structure of each part of the conductive diaphragm described in this utility model, as well as the position and connection relationship between each part.
[0066] like Figure 1 As shown, the conductive diaphragm of this utility model has a diaphragm 10, the overall shape of which is adapted to the shape of the miniature loudspeaker. In this embodiment, the diaphragm 10 is rectangular.
[0067] like Figures 4 to 7 As shown, the diaphragm 10 includes a diaphragm body 11 and a dome 12 bonded to the center of the diaphragm body 11; as Figure 5 and Figure 7 As shown, the diaphragm body 11 is a ring structure with a central hollow. The shape of the dome 12 matches the shape of the central hollow of the diaphragm body 11, and the dome 12 is bonded to the inner edge of the diaphragm body 11 by a ring of glue, thus forming a complete diaphragm 10; Figure 4 and Figure 6 As shown, the diaphragm body 11 is a complete structure (without a central cutout), and the diaphragm 10 is directly glued to the center of the diaphragm body 11 with a ring of glue.
[0068] The diaphragm body 11 is usually made of rubber material.
[0069] A conductive adhesive layer 20 is embedded on the surface of the diaphragm 10. After the conductive adhesive layer 20 is embedded in the diaphragm 10, a corresponding groove is formed on the surface of the diaphragm 10. The bottom surface of the groove is consistent with the shape of the lower surface of the conductive adhesive layer 20, which is also an arc surface with continuous curvature.
[0070] Regarding the location of the embedded groove, that is, the location where the conductive adhesive layer 20 is set, such as Figures 4 to 7 As shown, the recessed groove can be formed on the upper or lower side of the diaphragm body 11, and can be set according to actual installation needs or wire connection space, without specific limitations here.
[0071] Regarding the number of recessed grooves, that is, the number of conductive adhesive layers 20, such as... Figures 1 to 3 As shown, the recesses are usually arranged in pairs to correspond to the positive and negative terminals of the power supply, such as... Figure 1 As shown, a recessed groove is formed at each of the four corners of the diaphragm body 11, such as... Figure 2 As shown, an embedded groove is formed on each side of the diaphragm body 11, such as... Figure 3 As shown, two recessed grooves are formed on both sides of the diaphragm body 11.
[0072] Regarding the direction of the recess, that is, the extension direction of the conductive adhesive layer 20, since the recess and the conductive adhesive layer 20 are set to realize the electrical connection between the voice coil and the external circuit, the voice coil is usually installed at the center of the diaphragm 10, while the external circuit is located on the outer periphery of the diaphragm 10. Therefore, the extension direction of the recess is along the center of the diaphragm 10 toward the edge of the diaphragm 10.
[0073] Regarding the molding method of the embedded groove, the embedded groove can be integrally formed during the processing of the diaphragm 10, or it can be formed by embedding the conductive adhesive layer 20 in conjunction with the embedding of the conductive adhesive layer 20 during subsequent embedding.
[0074] According to one embodiment of the present invention, such as Figures 8 to 12 As shown, the conductive adhesive layer 20 has a smooth transition with continuous curvature at the connection between the middle part 21 and the transition part 22. That is, the lower surface of the entire conductive adhesive layer 20 is an arc surface with continuous curvature, and the bottom surface of the embedded groove that fits therewith is also an arc surface with continuous curvature.
[0075] The connection between the middle part 21 and the transition part 22 has a smooth transition with continuous curvature, which further reduces or even eliminates stress concentration between the diaphragm 10 and the conductive adhesive, thereby enhancing the structural reliability and durability of the conductive diaphragm under long-term vibration conditions.
[0076] According to one embodiment of the present invention, such as Figures 8 to 12As shown, a conductive adhesive layer 20 is embedded and fixed in the recessed groove on the diaphragm 10 of this invention. Along the thickness direction of the conductive adhesive layer 20, the conductive adhesive layer 20 protrudes from the recessed groove; that is, part of the conductive adhesive layer 20 is located inside the recessed groove, and part is located outside the recessed groove. The embedding depth of the conductive adhesive layer 20 on the diaphragm 10 is equal to the thickness of the middle portion 21 of the conductive adhesive layer 20 minus the height of the plane of the middle portion 21 of the conductive adhesive layer 20 protruding from the original plane of the diaphragm 10 (i.e., the height of the conductive adhesive layer 20 protruding from the surface of the diaphragm 10).
[0077] Furthermore, such as Figures 8 to 10 As shown, a protrusion is formed on the side of the diaphragm 10 opposite to the side that is attached to the conductive adhesive layer 20. The height of the protrusion on the lower surface of the diaphragm 10 = the overall height of the middle part of the conductive adhesive layer 20 after it is bonded to the diaphragm 10 - the height of the plane of the middle part 21 of the conductive adhesive layer protruding from the original plane of the diaphragm 10 - the original thickness of the diaphragm 10 (100 micrometers, not measured in the figure, 100 micrometers is the original thickness of the diaphragm when it is not bonded).
[0078] Specifically, the conductive adhesive layer 20 is embedded in the diaphragm 10 to a depth of 5% to 80% of its thickness, and the same depth accounts for 5% to 70% of the diaphragm 10's thickness. The height of the protrusion on the opposite side of the diaphragm 10 where it is attached to the conductive adhesive layer 20 is 0% to 55% of the original thickness of the diaphragm 10. Preferably, the conductive adhesive layer 20 is embedded in the diaphragm 10 to a depth of 5% to 50% of its thickness, and the same depth accounts for 5% to 40% of the diaphragm 10's thickness. The height of the protrusion on the opposite side of the diaphragm 10 where it is attached to the conductive adhesive layer 20 is 0% to 30% of the original thickness of the diaphragm 10.
[0079] Experimental results have shown that the above-mentioned embedding depth design can bring better acoustic and mechanical performance to the diaphragm 10, thereby extending the service life of the diaphragm 10. The specific test results and comparative analysis are shown below.
[0080] Specifically, the conductive adhesive layer 20 has a thickness of 10μm to 60μm, a width of 0.1mm to 6mm, and a length of 0.1mm to 6mm. Preferably, the conductive adhesive layer 20 has a thickness of 15μm to 40μm, a width of 0.2mm to 5mm, and a length of 0.2mm to 5mm. More preferably, the conductive adhesive layer 20 has a thickness of 20μm to 30μm, a width of 0.5mm to 4mm, and a length of 0.5mm to 4mm.
[0081] Specifically, such as Figures 8 to 12As shown, the conductive adhesive layer 20 is embedded in and bonded to the diaphragm 10. Along the width direction of the conductive adhesive layer 20, the conductive adhesive layer 20 includes a middle part 21 and transition parts 22 located on both sides of the middle part 21. Along the direction away from the middle part 21, the thickness of the transition parts 22 gradually decreases. The lower surfaces of the middle part 21 and the transition parts 22 of the conductive adhesive layer 20 are either flat or arc surfaces with continuous curvature, or a combination of the two. The connection between the middle part 21 and the transition parts 22 has a smooth transition with continuous curvature, without corresponding right angles or sharp corners. Therefore, there are no stress concentration points between the conductive adhesive layer 20 installed in the recess and the diaphragm 10, thereby improving the embedding and fixing effect of the two, strengthening the damping and protective effect of the rubber inside the diaphragm 10 on the conductive adhesive layer 20, preventing the conductive adhesive layer 20 from cracking or falling off during frequent vibration of the diaphragm 10, and enhancing the structural reliability and durability of the conductive diaphragm under long-term vibration conditions.
[0082] The conductive diaphragm in this invention can be prepared by pressing, spraying, or other methods. The conductive adhesive layer 20 will exhibit different degrees of hardness due to differences in its material and formulation. When the adhesive layer itself is relatively hard, i.e., its modulus is greater than 40 MPa, the diaphragm 10 in the conductive diaphragm will undergo bending deformation relative to the opposite plane of the conductive adhesive layer 20, such as... Figures 8 to 10 As shown; when the adhesive layer is relatively soft, i.e., the modulus is less than 20 MPa, the opposite plane of the diaphragm 10 will tend to form a planar state, such as Figure 11 and Figure 12 As shown, when the bulk modulus of the adhesive layer is appropriate, the state of the side plane will vary depending on the different preparation processes and parameters.
[0083] The two aforementioned manufacturing processes are merely illustrative examples of available manufacturing processes for the conductive diaphragm of this invention and are not intended to limit the manufacturing method used for the conductive diaphragm of this invention. By employing methods such as pressing and spraying, it is not necessary to pre-form adhesive application grooves on the diaphragm 10, thus achieving a good bond between the diaphragm 10 and the conductive adhesive layer 20. This not only ensures that the conductive adhesive layer 20 is less prone to delamination and failure but also guarantees excellent acoustic performance. Furthermore, it further reduces the number of process steps in the manufacturing process, significantly improving the yield rate of the finished conductive diaphragm.
[0084] To further test the effect of the depth of the conductive adhesive layer 20 embedded in the diaphragm 10 on the performance of the diaphragm 10 across the entire frequency range, the following experimental tests were conducted.
[0085] Example 1: As Figure 13As shown, the conductive adhesive layer 20 is embedded in the diaphragm 10 and bonded to it. Along the width direction of the conductive adhesive layer 20, it includes a central portion 21 and transition portions 22 located on both sides of the central portion 21. The lower surface of the central portion 21 is an arc surface with continuous curvature. Along the direction away from the central portion 21, the thickness of the transition portions 22 gradually decreases, and the lower surface of the transition portions 22 is also an arc surface with continuous curvature. The conductive adhesive layer 20 at the central portion 21 and the transition portions 22... The connection point features a smooth transition with continuous curvature. The conductive adhesive layer 20 protrudes from the surface of the diaphragm 10 along its thickness direction, and a protrusion is formed on the opposite side of the diaphragm 10 where it is attached to the conductive adhesive layer 20. Specifically, the conductive adhesive layer 20 is embedded in the diaphragm 10 by approximately 13 μm, accounting for 34.2% of its own thickness and 10.5% of the thickness of the diaphragm 10. The height of the protrusion on the opposite side of the diaphragm 10 where it is attached to the conductive adhesive layer 20 accounts for 10% of the original thickness of the diaphragm 10. The conductive adhesive layer 20 has a width of 4 mm and a length of 2 cm, and its resistance is 81 mΩ after electrical testing.
[0086] Example 2: Figure 14 As shown, the conductive adhesive layer 20 is embedded in the diaphragm 10 and bonded to it. Along the width direction of the conductive adhesive layer 20, it includes a central portion 21 and transition portions 22 located on both sides of the central portion 21. The lower surface of the central portion 21 is an arc surface with continuous curvature. Along the direction away from the central portion 21, the thickness of the transition portions 22 gradually decreases, and the lower surface of the transition portions 22 is also an arc surface with continuous curvature. The conductive adhesive layer 20 at the central portion 21 and the transition portions 22... The connection point features a smooth transition with continuous curvature. The conductive adhesive layer 20 protrudes from the surface of the diaphragm 10 along its thickness direction, and no protrusions are formed on the opposite side of the diaphragm 10 that is attached to the conductive adhesive layer 20. Specifically, the conductive adhesive layer 20 is embedded in the diaphragm 10 by approximately 11 μm, accounting for 18.0% of its own thickness and 10.5% of the thickness of the diaphragm 10. The height of the protrusion on the opposite side of the diaphragm 10 that is attached to the conductive adhesive layer 20 is 0% of the original thickness of the diaphragm 10. The conductive adhesive layer 20 has a width of 3.6 mm and a length of 1.8 cm, and its resistance is 83 mΩ after electrical testing.
[0087] Example 3: As Figure 15As shown, the conductive adhesive layer 20 is embedded in the diaphragm 10 and bonded to it. Along the width direction of the conductive adhesive layer 20, the conductive adhesive layer 20 includes a middle portion 21 and transition portions 22 located on both sides of the middle portion 21. The lower surface of the middle portion 21 is an arc surface with continuous curvature. Along the direction away from the middle portion 21, the thickness of the transition portions 22 gradually decreases, and the lower surface of the transition portions 22 is also an arc surface with continuous curvature. The conductive adhesive layer 20 is located at the connection between the middle portion 21 and the transition portions 22. For a smooth transition with continuous curvature, the conductive adhesive layer 20 protrudes from the surface of the diaphragm 10 along its thickness direction. The diaphragm 10 has a protrusion on the opposite side of the side that is attached to the conductive adhesive layer 20. Specifically, the conductive adhesive layer 20 is embedded in the diaphragm 10 for approximately 64.67 μm, accounting for 77.4% of its own thickness and 61.9% of the thickness of the diaphragm 10. The height of the protrusion on the opposite side of the diaphragm 10 that is attached to the conductive adhesive layer 20 accounts for 52.8% of the original thickness of the diaphragm 10. The conductive adhesive layer 20 has a width of 4.4 mm and a length of 2.2 cm, and its resistance is 74 mΩ after electrical testing.
[0088] Comparative Example 1: Figure 20 As shown, the conductive adhesive layer 20 is typically embedded in the groove of the diaphragm 10 in the form of a right angle or an angular shape. The thickness direction of the conductive adhesive layer 20 protrudes from the surface of the diaphragm 10, and no protrusion is formed on the opposite side of the diaphragm 10 that is attached to the conductive adhesive layer 20. Specifically, the conductive adhesive layer 20 is embedded in the diaphragm 10 for about 11 μm, accounting for 18.0% of the thickness of the conductive adhesive layer 20 itself and 10.5% of the thickness of the diaphragm 10. The height of the protrusion on the opposite side of the diaphragm 10 that is attached to the conductive adhesive layer 20 is 0% of the original thickness of the diaphragm 10.
[0089] Comparative Example 2: Figure 16 As shown, the conductive adhesive layer 20 is embedded in the diaphragm 10 and bonded to it. Along the width direction of the conductive adhesive layer 20, the conductive adhesive layer 20 includes a middle portion 21 and transition portions 22 located on both sides of the middle portion 21. The lower surface of the middle portion 21 is an arc surface with continuous curvature. Along the direction away from the middle portion 21, the thickness of the transition portion 22 gradually decreases, and the lower surface of the transition portion 22 is also an arc surface with continuous curvature. The conductive adhesive layer 20 has a smooth transition with continuous curvature at the connection between the middle portion 21 and the transition portion 22. The conductive adhesive layer 20 protrudes from the surface of the diaphragm 10 along its thickness direction, and the diaphragm 10 has a protrusion on the side opposite to the side covered by the conductive adhesive layer 20. Specifically, the conductive adhesive layer 20 is embedded in the diaphragm 10 for about 75 μm, accounting for 83% of the thickness of the conductive adhesive layer 20 itself and 92.5% of the thickness of the diaphragm 10. The height of the raised surface on the opposite side of the diaphragm 10 that is attached to the conductive adhesive layer 20 accounts for 56.5% of the original thickness of the diaphragm 10.
[0090] Comparative Example 3: Figure 21As shown, the conductive adhesive layer 20 is not embedded within the diaphragm 10, but only adheres to the upper surface of the diaphragm 10 on its lower surface. The conductive adhesive layer 20 has a width of 4 mm and a length of 2 cm, and its resistance was found to be 80 mΩ after an electrical test.
[0091] Examples 1, 2, and 3, as well as Comparative Examples 1 and 2, except for the structural differences between the conductive adhesive layer 20 and the diaphragm 10, all underwent vibration fatigue testing under the same conditions using a life testing instrument. Simultaneously, the sound pressure level of each conductive diaphragm at different frequencies was recorded during the vibration test. The test results are as follows: Figure 17 As shown.
[0092] Vibration fatigue testing was initiated. Comparative Example 1 failed to complete the full vibration fatigue test before fracturing, and Comparative Example 3 also failed to complete the full vibration fatigue test before the conductive adhesive layer 20 separated from the diaphragm 10. After the test, visual inspection revealed no obvious cracks on the surface of the conductive adhesive layer 20 in Examples 1, 2, 3, and Comparative Example 2. Microscopic examination using the light transmission mode also showed no cracks in the conductive adhesive portion (no light-transmitting cracks).
[0093] Therefore, it can be seen that the technical solution provided by this utility model (Examples 1-3 and Comparative Example 2) forms a smooth transition connection by pressing and embedding, which can complete the complete vibration fatigue test. In contrast, the surface bonding (Comparative Example 3) and right-angle groove embedding installation (Comparative Example 1) technical solutions in the prior art cannot complete the complete vibration fatigue test. It can be seen that the improved diaphragm structure of this utility model can significantly improve its fatigue resistance and service life.
[0094] according to Figure 17 The test results show that Examples 1 and 2 performed well across the entire frequency range. Example 3 showed a nearly 1 dB decrease in sound pressure level (SPL) in the low-frequency range (<300 Hz) and mid-to-high-frequency range (1000 Hz–10 kHz). Comparative Example 2 showed a significant performance decline across the entire frequency range, with a SPL decrease of 2–4 dB. A 1 dB decrease in SPL means that the SPL value (P) becomes approximately 89% of its original value; a 2–4 dB decrease means that the SPL value (P) becomes approximately 63%–79% of its original value.
[0095] Therefore, the technical solutions in embodiments 1-3 of this utility model have a relatively small impact on acoustic performance because the depth of the conductive adhesive layer 20 embedded in the diaphragm 10 and its proportion to the thickness of the conductive adhesive layer 20 are both within the reasonable range defined by this utility model. In contrast, the depth of the conductive adhesive layer 20 embedded in the diaphragm 10 and its proportion to the thickness of the conductive adhesive layer 20 in Comparative Example 2 are significantly higher (exceeding the reasonable range defined by this utility model), which has a certain impact on acoustic performance.
[0096] According to the test results of Examples 1-3 and Comparative Example 3, although the conductive diaphragm in this utility model needs to be pressed and composite shaped, by reasonably controlling the pressure, it can be extended to both sides on the one hand, and the depth of the conductive adhesive layer 20 embedded in the diaphragm 10 can be controlled within a certain range to keep the resistivity of the conductive adhesive layer 20 basically unchanged, that is, basically the same as the resistivity of the conductive adhesive layer before pressing and shaping, thus maintaining a good electrical conductivity effect.
[0097] To further illustrate the technical effect of the embedded bonding method in this utility model, the conductive diaphragm in this utility model ( Figure 8 ) and the method of simply attaching conductive adhesive to the surface of diaphragm 10 ( Figure 21 As shown, a reliability vibration test was also performed (observing the state of the conductive adhesive layer 20 without the conductive adhesive peeling off), and the test results are as follows. Figure 18 and Figure 19 As shown, the conductive adhesive layer 20 in this invention has no obvious cracks on its surface, while the existing attached conductive adhesive layer 20 has obvious cracks. Therefore, the embedded bonding method in this invention can effectively protect the conductive adhesive layer 20 and improve the life of the conductive diaphragm.
[0098] Implementation Method Two:
[0099] This utility model also provides a sound generating unit, which includes a magnetic gap formed by a magnet, a voice coil disposed in the magnetic gap, and a conductive diaphragm connected to the voice coil; wherein, the conductive diaphragm is the conductive diaphragm described in Embodiment 1, and the wire in the voice coil is electrically connected to the conductive adhesive layer 20 on the conductive diaphragm; the structure and technical effects of the conductive diaphragm have been described above, and will not be repeated here.
[0100] Implementation Method 3:
[0101] This utility model also provides an electronic device, which includes the sound-generating unit described in Embodiment 2; the structure and technical effects of the conductive diaphragm in the sound-generating unit have been described above and will not be repeated here.
[0102] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above descriptions are merely specific embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.
Claims
1. An electrically conductive diaphragm, characterized by The conductive diaphragm includes a diaphragm (10) and a conductive adhesive layer (20), wherein the conductive adhesive layer (20) is embedded in the diaphragm (10) and is bonded to the diaphragm (10). Along the width direction of the conductive adhesive layer (20), the conductive adhesive layer (20) includes a middle part (21) and transition parts (22) located on both sides of the middle part (21). The lower surface of the middle part (21) is a plane or an arc surface with continuous curvature or a combination of the above two surfaces. Along the direction away from the middle part (21), the thickness of the transition part (22) gradually decreases, and the lower surface of the transition part (22) is also an arc surface with continuous curvature.
2. The conductive diaphragm of claim 1, wherein, The conductive adhesive layer (20) has a smooth transition with continuous curvature at the connection between the middle part (21) and the transition part (22).
3. The conductive diaphragm of claim 1, wherein, The conductive adhesive layer (20) protrudes from the surface of the diaphragm (10) along its thickness direction.
4. The conductive diaphragm according to claim 1, characterized in that, The conductive adhesive layer (20) extends outward from the center of the diaphragm (10), and the conductive adhesive layer (20) is arranged in pairs.
5. The conductive diaphragm according to claim 3, characterized in that, The conductive adhesive layer (20) is embedded in the diaphragm (10) to a depth of 5% to 80% of the thickness of the conductive adhesive layer (20).
6. The conductive diaphragm according to claim 3, characterized in that, The conductive adhesive layer (20) is embedded in the diaphragm (10) to a depth of 5% to 50% of the thickness of the conductive adhesive layer (20).
7. The conductive diaphragm according to claim 5 or 6, characterized in that, The conductive adhesive layer (20) and the diaphragm (10) are compositely shaped by pressing.
8. The conductive diaphragm according to claim 1, characterized in that, The conductive adhesive layer (20) is embedded in the diaphragm (10) to a depth of 5% to 70% of the thickness of the diaphragm (10).
9. The conductive diaphragm according to claim 1, characterized in that, The conductive adhesive layer (20) is embedded in the diaphragm (10) to a depth of 5% to 40% of the thickness of the diaphragm (10).
10. The conductive diaphragm according to claim 1, characterized in that, The thickness of the conductive adhesive layer (20) is 10μm to 60μm, the width of the conductive adhesive layer (20) is 0.1mm to 6mm, and the length of the conductive adhesive layer (20) is 0.1mm to 6mm.
11. The conductive diaphragm according to claim 1, characterized in that, The thickness of the conductive adhesive layer (20) is 15μm to 40μm, the width of the conductive adhesive layer (20) is 0.2mm to 5mm, and the length of the conductive adhesive layer (20) is 0.2mm to 5mm.
12. The conductive diaphragm according to claim 1, characterized in that, The conductive adhesive layer (20) has a thickness of 20μm to 30μm, a width of 0.5mm to 4mm, and a length of 0.5mm to 4mm.
13. The conductive diaphragm according to claim 3, characterized in that, The height of the protrusion on the opposite side of the diaphragm (10) that is attached to the conductive adhesive layer (20) is 0% to 55% of the original thickness of the diaphragm (10).
14. A sound-generating unit, characterized in that, include: The magnetic gap formed by the magnet; A voice coil is placed within the magnetic gap; A conductive diaphragm is connected to the voice coil, wherein the conductive diaphragm is any one of claims 1-13, and the wires in the voice coil are electrically connected to the conductive adhesive layer (20) on the conductive diaphragm.
15. An electronic device, characterized in that, The electronic device includes the sound-generating unit as described in claim 14.