Conductive glue, voice diaphragm, preparation method of voice diaphragm and loudspeaker

Abstract

The invention relates to the technical field of loudspeakers, and discloses conductive glue, a voice diaphragm, a preparation method of the conductive glue and the voice diaphragm and a loudspeaker. The conductive glue comprises a conductive material, resin and an auxiliary agent, the conductive material includes a silver-containing material. A novel curing mode is provided, the conductive glue is not independently cured by a conventional constant high-temperature baking mode, the conductive glue and the voice diaphragm raw material are integrally formed together by adopting the process of gradual heating, high-temperature keeping and gradual cooling of the voice diaphragm, and the conductive glue can form a conductive layer consistent with the voice diaphragm in shape. And the conductive film and the voice diaphragm form a conductive film together, so that the new curing mode solves the phenomenon that cracks and peeling are easy to occur in the original curing mode.

Description

Technical Field

[0001] The present application relates to the technical field of loudspeakers, and in particular to a conductive glue and a sound membrane and a preparation method thereof, as well as a loudspeaker. Background Art

[0002] The sound membrane of a traditional speaker is directly coupled to the connected air through its surface. When the sound membrane vibrates, it drives the air to vibrate, thereby emitting and transmitting sound. Among them, the preparation methods of the sound membrane generally include the following two methods:

[0003] One is to first apply the conductive glue to the sound film raw material, then bake the conductive glue at a constant high temperature to form a solid conductive layer, and finally form the sound film; but this process is likely to cause obvious cracks on the sound film (see Figure 6 and Figure 7 ), the cracks will affect the vibration mode of the speaker, and the conductive layer will connect to the voice coil of the speaker. This crack will cause the impedance to increase or even break, thus affecting the electrical performance of the speaker;

[0004] The second method is to first form the sound film material, then apply conductive glue to the formed sound film, and finally bake the conductive glue at a constant high temperature to cure it; however, this method is prone to peeling and bulging on the sound film (see Figure 8 ), peeling and bulging phenomena will also affect the mode of the speaker during vibration. At the same time, when the speaker is vibrating, cracks are likely to occur at the peeling and bulging positions of the sound membrane, which will affect the electrical performance of the speaker. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a conductive glue, so that the conductive glue can be integrally formed with the sound film raw material using the sound film forming method, thereby avoiding the cracks and peeling that are easy to occur in the conventional sound film preparation process;

[0006] Another object of the present application is to provide a sound film prepared by using the above-mentioned conductive glue and a preparation method thereof;

[0007] Another object of the present application is to provide a loudspeaker comprising the above-mentioned sound membrane.

[0008] In order to solve the above technical problems / achieve the above purposes or at least partially solve the above technical problems / achieve the above purposes, as a first aspect of the present application, a conductive glue is provided, which comprises 5-15% conductive material, 15-30% resin, and the remainder is an auxiliary agent by mass; wherein the conductive material comprises a silver-containing material.

[0009] Optionally, the silver-containing material includes one or more of silver filaments, silver sheets, silver glue, and silver wires; and the resin includes one of polyurethane, polyimide, and PDMS silicone.

[0010] As a second aspect of the present application, a sound membrane is provided, comprising a sound membrane body and a conductive layer, wherein the conductive layer is formed by curing the conductive glue described in the present application.

[0011] As a third aspect of the present application, a method for preparing the sound membrane is provided, comprising:

[0012] The conductive glue described in the present application is coated on the sound membrane raw material to obtain a diaphragm to be formed, and the diaphragm to be formed is integrally formed.

[0013] Optionally, the sound membrane raw material includes one of thermoplastic polyurethane elastomer, thermoplastic elastomer, polyetheretherketone rubber, rubber and silicone.

[0014] Optionally, the one-piece molding process of the to-be-molded membrane includes:

[0015] S1, placing the diaphragm to be formed in a sound diaphragm forming mold;

[0016] S2, preforming the film to be formed;

[0017] S3, curing the preformed diaphragm to be formed to obtain the sound membrane.

[0018] Optionally, step S2 comprises: gradually heating the film to be formed from 50° C. to 120-190° C. and maintaining the temperature for 2-60 seconds,

[0019] Step S3 includes: gradually cooling the preformed film to be formed to 30-80° C.;

[0020] Further optionally, in step S2, when the temperature of the diaphragm to be formed rises to 70-150°C, air pressure is applied to the cavity of the sound membrane forming mold so that the air pressure in the cavity of the sound membrane forming mold is maintained at 0.2-0.8Mpa, and the diaphragm to be formed is completely cured.

[0021] As a fourth aspect of the present application, a speaker is provided, comprising the sound membrane described in the present application.

[0022] The present application provides a new type of curing method, in which the conductive glue is no longer cured by the conventional constant high-temperature baking method alone, but is integrally formed together with the sound membrane raw material by the process of gradually heating up the sound membrane - maintaining high temperature - gradually cooling the sound membrane. The conductive glue can form a conductive layer consistent with the shape of the sound membrane, and together with the sound membrane form a conductive film. This new curing method solves the problem of cracking and peeling that is prone to occur in the original curing method. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application.

[0024] Figure 1 Shown is a schematic diagram of the microstructure of silver filaments and silver particles;

[0025] Figure 2 Shown is a physical diagram of the preparation process of the example sound film of this application;

[0026] Figure 3 Shown is the molding process curve of the example sound film of this application;

[0027] Figure 4 Shown is a schematic diagram of the process of the example sound film of this application;

[0028] Figure 5 Shown is an enlarged view of the raised portion of the example sound membrane of the present application;

[0029] Figure 6 and Figure 7 Shown is a physical picture of the sound membrane prepared in the first conventional manner;

[0030] Figure 8 Shown is a real picture of the sound membrane prepared in the second conventional way;

[0031] Fig. 9 The figure shows a schematic diagram of the test points for testing the impedance of the sound film of the example of this application;

[0032] Fig.10 Shown are the impedance test results of sound membranes prepared with different silver wire content formulas. DETAILED DESCRIPTION

[0033] The present application discloses a conductive glue and a sound film, a method for preparing the same, and a loudspeaker. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve the same. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all deemed to be included in this application. The products, methods, and applications described in this application have been described through preferred embodiments. Relevant personnel can obviously modify or appropriately change and combine the products, methods, and applications described in this article without departing from the content, spirit, and scope of this application to implement and apply the technology of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0034] It should be noted that, in this article, if relational terms such as "first" and "second", "step 1" and "step 2", and "(1)" and "(2)" appear, they are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements. At the same time, the embodiments in this application and the features in the embodiments may be combined with each other without conflict.

[0035] In the preparation process of the sound film, the conductive glue is generally cured by constant high-temperature baking. However, the present application adjusts the composition of the conductive glue and increases the resin component. In the conductive glue containing the silver material, it mainly ensures the uniform arrangement of the silver-containing material to prevent its accumulation and agglomeration. At the same time, it also ensures that the conductive layer after molding has the characteristics of elasticity and flexibility, and is not prone to cracks, peeling, bubbling and other phenomena. The conductive glue can also be molded on the surface of the sound film involving curved surfaces. Therefore, in the first aspect of the present application, a conductive glue is provided, which includes 5-15% conductive material and 15-30% resin by mass, and the remainder is an auxiliary agent; the conductive material includes a silver-containing material, and the silver-containing material mainly plays a conductive role.

[0036] In certain embodiments of the present application, the resin includes one of polyurethane, polyimide, and PDMS silicone. These materials have certain high temperature resistance and flexibility. The high temperature resistance can ensure that the conductive glue adapts to the molding conditions of the sound membrane, and the flexibility can prevent the conductive layer from cracking during the molding process.

[0037] In certain embodiments of the present application, the silver-containing material includes one or more of silver wire, silver sheet, silver glue, and silver line; silver wire, silver sheet, silver glue, silver wire, and other continuous silver-containing materials are staggered in the conductive glue, and silver wire is used as an example (see Figure 1 ), silver wire is bendable, which is suitable for the sound membrane of the speaker. When the speaker makes sound, the sound membrane will vibrate. The bendability of nano silver wire can ensure that the impedance of the conductive layer of the sound membrane will not change when it vibrates. If silver particles, a discontinuous silver-containing material (see Figure 1), because it is not bendable, when the sound film vibrates and stretches, a distance will be formed between the silver particles, resulting in unstable impedance. In some other embodiments of the present application, the wire diameter of the silver wire is nanometer-level, about 10-30nm, and the length is micrometer-level, about 10-30μm.

[0038] In certain embodiments of the present application, the auxiliary agent includes but is not limited to a promoter, a leveling agent, and a defoaming agent, etc. The auxiliary agent component is a conventional component of conductive glue, which can assist silver wire and other silver-containing materials to draw different shapes in a liquid state by dispensing or spraying, and then solidify into a stable state. The auxiliary agent can be directly purchased by purchasing a commercially available composite auxiliary agent, or a single auxiliary agent can be purchased for preparation. In some other embodiments of the present application, the conductive glue includes different contents of conductive materials, such as 10%, 11%, 12%, etc. The amount of conductive material can be adjusted according to the different application scenarios of the sound membrane product. For example, the sound membrane product has high requirements for bendability, and the bendability can be increased by reducing the silver wire content, but the impedance will increase accordingly.

[0039] In a second aspect of the present application, a sound membrane is provided, comprising a sound membrane body and a conductive layer, wherein the conductive layer is formed by curing the conductive glue described in the present application. The shape of the sound membrane can be set according to the actual needs of the speaker, and is not limited here.

[0040] In certain embodiments of the present application, the sound membrane is a rectangular member having a through hole in the middle, and the rectangular member has a conductive layer extending along the wide side direction. Preferably, the conductive layer is located in the middle of the long side of the rectangular member and is symmetrically arranged on both sides of the through hole; one side of the rectangular member having the conductive layer is protruding with an annular protrusion, and the annular protrusion extends along the circumference of the rectangular member and is connected end to end; see the structural schematic diagram Figure 2 .

[0041] In some other embodiments of the present application, the through hole includes but is not limited to circular, rectangular, square, semicircular, triangular, diamond, etc., or any combination of these shapes, such as a capsule-shaped through hole.

[0042] In a third aspect of the present application, a method for preparing the sound membrane is provided, comprising:

[0043] The conductive glue described in the present application is coated on the sound membrane raw material to obtain a diaphragm to be formed, and the diaphragm to be formed is integrally formed.

[0044] In certain embodiments of the present application, the sound membrane raw material includes one of thermoplastic polyurethane elastomer (TPU), thermoplastic elastomer (TPE), polyetheretherketone rubber (PEEK), rubber and silicone. Among them, different sound membrane raw materials correspond to different molding methods, PEEK / TPU / TPE all adopt air compression molding, rubber adopts solid mold up and down extrusion molding, silicone adopts injection molding and baking molding or dispensing and then upper and lower mold UV lamp curing molding. In some other embodiments of the present application, the sound membrane raw material uses PEEK, TPU or TPE.

[0045] In certain embodiments of the present application, the one-piece molding process of the film to be formed includes:

[0046] S1, placing the diaphragm to be formed in a sound diaphragm forming mold;

[0047] S2, preforming the film to be formed;

[0048] S3, curing the preformed diaphragm to be formed to obtain the sound membrane.

[0049] In certain embodiments of the present application, step 2 comprises:

[0050] The film to be formed is gradually heated from 50°C to 120-190°C and maintained for 2-60s;

[0051] In some other embodiments of the present application, in step S2, when the temperature of the diaphragm to be formed rises to 70-150°C, air pressure is applied to the cavity of the sound membrane forming mold to keep the air pressure in the cavity of the sound membrane forming mold at 0.2-0.8Mpa until the diaphragm to be formed is completely solidified.

[0052] In certain embodiments of the present application, step S3 includes:

[0053] The preformed film to be formed is gradually cooled to 30-80°C.

[0054] The one-piece molding process of the diaphragm to be formed includes a heating zone, a high temperature holding zone and a cooling zone. The heating zone and the high temperature holding zone are the molding zones of the diaphragm to be formed, which ensure that the conductive glue is adhered to the sound membrane raw material according to the shape of the mold in a flowing state and pre-formed into a shape consistent with the sound membrane, while the cooling zone ensures that the conductive glue is completely cured to form a cured sound membrane; wherein, the high temperature holding zone is 120-190°C, and the holding time is 2s-60s. The temperature and holding time of the high temperature holding zone can be adjusted according to different molding requirements.

[0055] During the heating process, the temperature before 50°C has little effect on the sound membrane forming. At this time, the heating can be appropriately accelerated to save time. This application specifies the forming curve from 50°C to 120-190°C as the heating zone. Too fast or too slow heating / cooling rates are not conducive to the sound membrane forming. In some other embodiments of the present application, the heating rate is 1-5°C / s, such as 1°C, 2°C, 3°C, 4°C or 5°C, preferably 1-3°C / s, such as 1.1°C, 1.2°C, 1.3°C, 1.4°C, 1.5°C, 1.6°C, 1.7°C, 1.8°C, 1.9°C, 2.0°C, 2.1°C, 2.2°C, 2.3°C, 2.4°C, 2.5°C, 2.6°C, 2.7°C, 2.8°C, 2.9 ℃, 3.0℃; the cooling rate is 1-5℃ / s, such as 1℃, 2℃, 3℃, 4℃ or 5℃, preferably 1-3℃ / s, such as 1.1℃, 1.2℃, 1.3℃, 1.4℃, 1.5℃, 1.6℃, 1.7℃, 1.8℃, 1.9℃, 2.0℃, 2.1℃, 2.2℃, 2.3℃, 2.4℃, 2.5℃, 2.6℃, 2.7℃, 2.8℃, 2.9℃, 3.0℃;

[0056] In certain embodiments of the present application, the air pressure is 0.2-0.8Mpa, for example, 0.2, 0.4, 0.6 or 0.8Mpa. If the air pressure is lower than this, the molding may be incomplete and the expected molding shape may not be achieved. If the air pressure is higher than this, the sound membrane will be partially accumulated with glue, resulting in changes in the rigidity of the sound membrane and thus affecting the sound quality.

[0057] In a fourth aspect of the present application, a speaker is also provided, comprising the sound membrane described in the present application.

[0058] The following is a further description of a conductive glue and a sound membrane, a preparation method thereof, and a speaker provided in this application.

[0059] Example 1: Preparation of the Example Sound Film of the Application

[0060] Place the PEEK, TPU or TPE raw material on the carrier and fix it with a pressing plate, see Figure 2 first step;

[0061] The conductive silver wire glue is obtained by uniformly mixing the nano silver wire, the polyurethane resin and the auxiliary agent, wherein the silver wire content is 10%, the polyurethane resin content is 25%, and the balance is the auxiliary agent, which is a commercially available commodity and contains conventional accelerators, leveling agents and defoamers; the conductive silver wire glue is applied on the sound film raw material by dispensing, spraying or steel screen printing. Figure 2 In the second step, the sound film is in a flat state before molding, and the conductive silver wire glue is in liquid state;

[0062] Place the sound film raw material coated with conductive silver glue on the sound film forming mold. Figure 2 Step 3;

[0063] Turn on the molding machine to mold the sound film material coated with conductive silver glue. The molding process curve is shown in Figure 3 , the specific process is as follows:

[0064] Heating zone: from 50℃ to 180-185℃ (1-3℃ / s, the impact before 50℃ is small and the heating can be controlled as needed);

[0065] High temperature holding area: 180-185℃ for 2-60s;

[0066] Cooling zone: Cooling to mold opening temperature 50℃ (1-3℃ / s);

[0067] Air pressure control: When the temperature in the heating zone rises to about 135°C, apply 0.4MPa of air pressure until the cooling is completed.

[0068] After the sound film is formed, it is punched and the product is taken out. Figure 2 Step 4: Obtain the finished sound film;

[0069] The raised areas around the finished sound film are enlarged. Figure 4 ,Depend on Figure 4 It can be seen intuitively that the conductive silver wire glue and the sound membrane raw material are formed together, without the phenomenon of cracks, bubbles and bulging that are easily produced by other conventional curing methods.

[0070] Example 2: Preparation of conventional sound film

[0071] (1) Method 1

[0072] First, the conductive glue is applied to the sound film raw material, and then the conductive glue is baked at a constant high temperature of 120° C. to form a solid conductive layer, and finally the sound film is formed; the parameters refer to Example 1;

[0073] The raised positions around the finished sound film are enlarged to see Figure 6 and Figure 7 ,from Figure 6 It can be clearly seen that there are obvious cracks around the bulge. Figure 7 After magnifying the local location 1000 times, it can be seen that the crack width is about 10μm.

[0074] (2) Method 2

[0075] First, the sound film raw material is formed, and then the conductive glue is coated on the formed sound film, and finally the conductive glue is baked and cured at a constant high temperature of 120° C.; the parameters refer to Example 1;

[0076] The raised positions around the finished sound film are enlarged to see Figure 8 ,from Figure 8It can be clearly seen that there is obvious peeling and bulging around the bulge.

[0077] Example 3: Sound film impedance test of this application example

[0078] Conductive silver wire glue formula 1: silver wire content 10%, polyurethane resin content 25%, the rest is auxiliary agent;

[0079] Conductive silver wire glue formula 2: silver wire content 11%, polyurethane resin content 25%, the rest is auxiliary agent;

[0080] Conductive silver wire glue formula 3: silver wire content 12%, polyurethane resin content 25%, the rest is auxiliary agent;

[0081] The above three conductive glue formulas were used to prepare the sound film according to the method of Example 1. Fig. 9 The impedance test points shown are tested and the results are shown in Fig.10 ;Depend on Fig.10 It can be seen that the impedance size can be achieved by adjusting the silver content of the conductive silver glue. The impedance size can be determined according to the product application scenario. For example, some sound membrane products have high requirements for bendability, and the bendability can be increased by reducing the silver content, but the impedance will increase accordingly, which is consistent with the impedance result of formula one.

[0082] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A conductive glue, It is characterized in that The conductive glue comprises 5-15% conductive material, 15-30% resin, and the remainder is auxiliary agent by mass; wherein the conductive material comprises silver-containing material.

2. The conductive glue according to claim 1, It is characterized in that The silver-containing material includes one or more of silver filaments, silver sheets, silver glue, and silver wires.

3. The conductive glue according to claim 1, It is characterized in that The resin includes one of polyurethane, polyimide and PDMS silica gel.

4. A sound film, It is characterized in that It comprises a sound membrane body and a conductive layer, wherein the conductive layer is formed by curing the conductive glue described in any one of claims 1 to 3.

5. The method for preparing the sound membrane according to claim 4, It is characterized in that include: The conductive glue described in any one of claims 1 to 3 is coated on the sound membrane raw material to obtain a diaphragm to be formed, and the diaphragm to be formed is integrally formed.

6. The preparation method according to claim 5, It is characterized in that The sound membrane raw material includes one of thermoplastic polyurethane elastomer, thermoplastic elastomer, polyetheretherketone rubber, rubber and silicone.

7. The preparation method according to claim 5, It is characterized in that The one-piece forming process of the diaphragm to be formed comprises: S1, placing the diaphragm to be formed in a sound diaphragm forming mold; S2, preforming the film to be formed; S3, curing the preformed diaphragm to be formed to obtain the sound membrane.

8. The preparation method according to claim 8, It is characterized in that Step S2 includes: The film to be formed is gradually heated from 50°C to 120-190°C and maintained for 2-60s; Step S3 includes: The preformed film to be formed is gradually cooled to 30-80°C.

9. The preparation method according to claim 8, It is characterized in that In the step S2, when the temperature of the diaphragm to be formed rises to 70-150°C, air pressure is applied to the cavity of the sound membrane forming mold to keep the air pressure in the cavity of the sound membrane forming mold at 0.2-0.8Mpa until the diaphragm to be formed is completely solidified.

10. A loudspeaker, It is characterized in that Includes the sound membrane as described in claim 5.

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