Manufacturing method of conductive damper, conductive damper and loudspeaker

Abstract

The invention relates to a manufacturing method of a conductive damper, the conductive damper and a loudspeaker. The manufacturing method comprises the following steps: applying conductive slurry with the viscosity of 100-1000mPas to the damper to form a conductive wet film layer; curing the formed conductive wet film layer; repeating the steps at least once; wherein when the steps are not executed for the last time, the conductive wet film layer is subjected to low-temperature curing, the curing temperature is 60-80 DEG C, and the curing time is 5-10 min; when the steps are not executed for the first time, the conductive slurry is applied to the surface of the existing conductive wet film layer after low-temperature curing; when the steps are executed for the last time, high-temperature curing is conducted on the conductive wet film layer, the curing temperature ranges from 100 DEG C to 120 DEG C, the curing time ranges from 30 min to 60 min, and the conductive damper is obtained. According to the invention, the thickness uniformity of the covering of the conductive slurry on the damper is improved, and the resistance uniformity of the conductive layer of the damper is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of loudspeakers, in particular to a method for manufacturing a conductive suspension, a conductive suspension and a loudspeaker. BACKGROUND

[0002] A large-size loudspeaker is usually composed of a voice coil, a suspension, a basket, a cone, a magnet, etc., wherein the voice coil and external circuit are connected by a flexible silk thread, and the silk thread is prone to breakage due to continuous up-and-down displacement during the operation of the loudspeaker. In order to avoid the breakage of the silk thread, the length of the silk thread needs to be increased and fixed at a proper position, which is a complicated process and not suitable for automatic production, and the silk thread may have resonance, affecting the sound quality, and may also cause unbalanced vibration of the suspension, resulting in eccentric vibration, which also affects the sound quality and product reliability.

[0003] In order to solve the above technical problems, the conductive adhesive is applied to the suspension in the prior art to replace the silk thread for connecting with the external circuit. Due to the existence of wave peaks and wave troughs on the suspension, the conventional conductive adhesive is difficult to uniformly cover during the coating process, and is prone to accumulate in the wave troughs, resulting in inconsistent thickness, low resistance uniformity, increased local stiffness, asymmetric vibration mode of the suspension, and high-frequency harmonic distortion. In addition, the conductive filler network may be discontinuous due to the too thin adhesive layer on the wave peaks, which increases the local resistance and affects the impedance curve of the loudspeaker. How to uniformly cover the conductive adhesive on the suspension is a technical problem to be solved in the field. SUMMARY

[0004] Therefore, the present application provides a method for manufacturing a conductive suspension, a conductive suspension and a loudspeaker, which improves the thickness uniformity of the conductive paste on the suspension and the resistance uniformity of the conductive layer of the suspension.

[0005] To solve the above technical problems, the present application provides a method for manufacturing a conductive suspension, comprising the following steps: applying a conductive paste with a viscosity of 100-1000 mPas to the suspension to form a conductive wet film layer; curing the formed conductive wet film layer; repeating the above steps at least once; wherein, when the above steps are not performed for the last time, the conductive wet film layer is cured at a low temperature, the curing temperature is 60-80℃, and the curing time is 5-10min; when the above steps are not performed for the first time, the conductive paste is applied to the surface of the existing conductive wet film layer after low-temperature curing; when the above steps are performed for the last time, the conductive wet film layer is cured at a high temperature, the curing temperature is 100-120℃, the curing time is 30-60min, and a conductive suspension is obtained.

[0006] Further, the conductive paste comprises the following components by weight percentage: polyurethane resin 3%-10%, nano silver wire 5%-10%, thickening agent 0.2%-1%, dispersing agent 0.1%-3%, leveling agent 0.1%-0.5%, and solvent 70%-85%.

[0007] Further, the nano silver wire has a wire diameter of 10-40 nm, a wire length of 10-50 um, and a silver content of 5%-15%.

[0008] Further, the conductive paste is sprayed on the spring plate by air pressure spraying, the air pressure of the spray gun is controlled at 0.1-0.2 MPa, and the thickness of the conductive wet film obtained by each application is 10-100 um.

[0009] Further, the thickness of the conductive wet film obtained by each application of the conductive paste is 15-20 um.

[0010] Further, the total thickness of the multi-layer conductive wet film layer after high-temperature curing obtained by multiple applications of the conductive paste is not more than 50 um.

[0011] Further, when applying the conductive paste, a mask is covered on the surface of the spring plate; the mask has a hollow pattern matched with the shape of the conductive wet film layer, and the conductive paste is applied to the hollow pattern of the mask.

[0012] Further, when curing the conductive wet film layer, the spring plate with the conductive wet film layer is sent into an oven for baking and curing.

[0013] The application also provides a conductive spring plate made by the manufacturing method.

[0014] The application also provides a loudspeaker comprising the conductive spring plate.

[0015] The above technical solutions of the application have the following advantages compared with the prior art: The manufacturing method of the conductive spring plate, the conductive spring plate and the loudspeaker have the following advantages: on the one hand, the viscosity of the conductive paste is controlled to be 100-1000 mPas, so that the conductive paste is easy to apply and spread, and the viscosity of the conductive paste is not too low, so that the conductive paste is not prone to excessive liquid penetration and liquid accumulation; on the other hand, the conductive paste is applied in layers, low-temperature curing is performed in layers, and finally high-temperature curing is performed, so that the thickness of the paste applied in each layer is thin, the adhesion is increased, the problem of uneven thickness caused by surface paste flow is not prone to occur, and the bonding force of the conductive wet film layers of different layers is strong; thus, the thickness uniformity of the conductive paste on the surface of the spring plate can be ensured, and the uniformity of the resistance of the conductive layer is improved. 2) The method for manufacturing the conductive dome of the present application, through the cooperation of multiple air pressure spraying and water-based solvent system, the conductive paste is easy to apply and spread, and the conductive coating can have good uniformity in the face of the irregular structure of the dome surface, so that the resistance difference rate between the repeated irregular structure areas and the average value of the resistance is within 10%, and the electrical performance consistency is excellent, and the resistance difference rate of the conductive wet film layer at different positions of the dome surface and the target resistance is low. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the drawings.

[0017] Figure 1 is a top view of the conductive dome in the present application; Figure 2 is a longitudinal sectional view of the conductive dome in the present application.

[0018] Description of the drawings: 1, dome; 2, conductive layer. DETAILED DESCRIPTION

[0019] The present application will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present application and implement it, but the embodiments are not limiting to the present application.

[0020] Referring to Figure 1 and Figure 2 , a structure of the conductive dome manufactured by the present application.

[0021] The conductive dome includes a dome 1 and two conductive layers 2, the dome 1 is used to be sleeved on the outside of the voice coil, the surface of the dome 1 has multiple wave crests and wave troughs, the two conductive layers 2 are independently formed on the surface of the dome 1, the conductive layers 2 are arranged on the surface of the dome 1, one end of each of the conductive layers 2 extends to the inner edge of the dome 1 and is used to be electrically connected with the voice coil, the other end of each of the conductive layers 2 extends to the outer edge of the dome 1 and is used to be electrically connected with the external circuit, the conductive layers 2 include multiple wave crest conductive parts located at the wave crests of the dome 1 and multiple wave trough conductive parts located at the wave troughs of the dome 1.

[0022] The method for manufacturing the conductive dome includes the following steps: The conductive paste with a viscosity of 100-1000 mPas is applied to the dome to form a conductive wet film layer; The formed conductive wet film layer is cured; The above steps are repeatedly executed at least once; Among them, when the above steps are not executed for the last time, the conductive wet film layer is cured at low temperature, the curing temperature is 60-80℃, and the curing time is 5-10min. The conductive paste is applied on the surface of the existing low-temperature cured conductive wet film layer when the above steps are not performed for the first time; The conductive wet film layer is high-temperature cured when the above steps are performed for the last time, the curing temperature is 100-120℃, and the curing time is 30-60min, to obtain a conductive spring wave.

[0023] In the above, the viscosity of the conductive paste is the resistance to flow exhibited by the conductive paste, and the viscosity of the conductive paste affects its flow performance. Specifically, because the spring wave not only has pores on the surface, but also has a wavy shape in cross-section. Too low viscosity leads to glue sagging, and too high viscosity leads to serious orange peel, poor leveling, and poor spraying atomization effect. Specifically, the viscosity of the conductive paste can be set to 100mPas, 150mPas, 200mPas, 250mPas, 300mPas, 350mPas, 400mPas, 450mPas, 500mPas, 550mPas, 600mPas, 650mPas, 700mPas, 750mPas, 800mPas, 850mPas, 900mPas, 950mPas or 1000mPas.

[0024] The number of repetitions of the above steps is calculated according to the relationship between the total thickness of the multi-layer conductive wet film layer obtained by high-temperature curing after multiple applications of the conductive paste and the thickness of the conductive wet film layer obtained by single application of the conductive paste. The above steps are not performed for the last time, which means other times before the last time (excluding the last time). The above steps are not performed for the first time, which means other times after the first time (excluding the first time).

[0025] The low-temperature curing temperature is the temperature for drying the surface of the conductive paste, and the low-temperature curing time is the time for drying the surface of the conductive paste. The low-temperature curing temperature and the low-temperature curing time of the conductive paste are set according to the viscosity of the conductive paste. Specifically, the low-temperature curing temperature can be set to 60℃, 65℃, 70℃, 75℃ or 80℃. The low-temperature curing time is 5-10min, specifically, the low-temperature curing time can be 5min, 6min, 7min, 8min, 9min or 10min. The temperature and time of the non-final curing of the conductive paste are controlled within a certain range, which can ensure that the conductive paste is only surface dried. After low-temperature curing, a semi-cured film is formed on the surface of the paste, but the inside still maintains a state that can be superimposedly coated; The high-temperature curing temperature is a temperature for guiding the internal curing of the conductive paste. The high-temperature curing time of the conductive paste is a time for guiding the internal curing of the conductive paste. The high-temperature curing temperature and the high-temperature curing time of the conductive paste are set according to the thickness and the viscosity of the conductive paste. Specifically, the high-temperature curing temperature can be set to 100°C, 105°C, 110°C, 115°C, or 120°C. The curing time is 30-60 min, and specifically, the curing time can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, or 60 min. The temperature and the time of the last baking of the conductive paste are controlled within a certain range, which can ensure the internal curing of the conductive paste. After high-temperature curing, the conductive paste as a whole is in a solidified state. After high-temperature curing, the multi-layer conductive wet film layer formed by at least two times of applying the conductive paste is the conductive layer 2 described above.

[0026] Specifically, the conductive paste is layered and applied on the spring 1, and the thickness of each layer of the wet film is controlled within the flowable range to avoid the accumulation of the valleys caused by the single over-thickness. After each application of the conductive paste, the conductive paste is dried. The non-last drying forms a tack-free layer, which serves as an intermediate support layer to prevent the secondary flow of the underlying paste during subsequent coating and ensure the uniform distribution of the thickness of each layer. The last drying makes the multi-layer conductive paste form an overall conductive layer structure.

[0027] Through the above technical solution, on the one hand, by controlling the viscosity of the conductive paste within a certain range, the viscosity of the conductive paste is not too high, so that the conductive paste is easy to apply and spread, and the viscosity of the conductive paste is not too low, so that the conductive paste is not prone to seepage transition and liquid accumulation; on the other hand, by the way of layered application of the conductive paste, layered low-temperature curing, and finally high-temperature curing, the thickness of the paste applied in each layer is thin, which increases the adhesion and prevents the problem of uneven thickness caused by surface flow of the paste, and the bonding force of the conductive wet film layers of different layers is strong. Thus, the thickness uniformity of the conductive paste on the surface of the spring can be ensured, and the uniformity of the resistance of the conductive layer is improved.

[0028] In some embodiments, the conductive paste described above comprises the following components in the following weight percentages: polyurethane resin 3%-10%, nano-silver wire 5%-10%, thickening agent 0.2%-1%, dispersing agent 0.1%-3%, leveling agent 0.1%-0.5%, and solvent 70%-85%.

[0029] In the above, the polyurethane resin is a high molecular material formed by polycondensation reaction of polyol and polyisocyanate, which has excellent mechanical properties and strong plasticity. The main chain of the polyurethane resin contains urethane groups, which makes it have high tensile strength, good impact resistance, superior aging resistance, drug resistance, small volume, light weight and other characteristics. The above polyurethane resin contains one or more of polyester, polyether and polycarbon polyurethane. The nanosilver wire is a nanomaterial with specific geometric shape and physical and chemical properties. The nanosilver wire is a one-dimensional structure with a transverse size below 100 nanometers and no longitudinal limit, and its aspect ratio is usually greater than 100. This structure makes the nanosilver wire have high specific surface area, excellent electrical conductivity, good flexibility and transparency, etc. The thickening agent is a substance that can increase the viscosity of latex and liquid, also known as a gelling agent or paste. It can keep the system uniform and stable in suspension or emulsion state, or form a gel by increasing the viscosity of the system. The above thickening agent includes one or more of cellulose thickening agent, polyurethane thickening agent, polyacrylic acid thickening agent and polyoxyethylene thickening agent. The above leveling agent includes one or more of BYK-3565, BYK-333, BYK-307, BYK-377, BYK-378, BYK-352, BYK-354 and BYK-358. The dispersant is used to disperse particles uniformly, avoid particle aggregation and improve the stability of the mixture. The leveling agent is used to reduce the surface tension of the liquid and improve the surface properties. The solvent is used to dissolve solids, liquids or gaseous solutes to form a solution. The above dispersant includes one or more of BYK-110, BYK-142, BYK-160, BYK-161, BYK-162, BYK-180 and BYK-182; the above solvent includes one or more of water, isopropyl alcohol, ethanol and propylene glycol methyl ether. The solvent includes water, isopropyl alcohol, ethanol, propylene glycol methyl ether, etc. Specifically, the preparation process of the conductive paste includes the following sub-steps: S1.1, prepare each component of the conductive paste described above; S1.2, add the polyurethane resin into the solvent to dissolve the polyurethane resin in the solvent to obtain a first mixed solution; S1.3, add the thickening agent, leveling agent and dispersant into the first mixed solution, stir uniformly to obtain a second mixed solution; S1.4, add the dispersion liquid of nanosilver wire into the second mixed solution, stir uniformly to obtain a third mixed solution; S1.5, grind the third mixed solution, then disperse and deaerate to obtain the conductive paste.

[0030] The nanosilver wire dispersion liquid includes nanosilver wires, in addition, includes a solvent and a dispersant, and is generally used in the state of the nanosilver wire dispersion liquid.

[0031] By the above technical solution, the high-elasticity polyurethane resin has a high soft segment ratio in the molecular structure, which provides a breaking elongation rate of more than 100%. By adjusting the proportions of the thickening agent, the dispersant, the leveling agent, and the solvent, the polyurethane resin has a viscosity of 100-1000 mPas and suitable wettability. The contents of the polyurethane resin, the nanosilver wires, the thickening agent, the dispersant, the leveling agent, and the solvent are set within a certain range, so that the viscosity, the resistivity, and the breaking elongation rate of the conductive paste are maintained within the required range.

[0032] In some embodiments, the nanosilver wires have a wire diameter of 10-40 nm, a wire length of 10-50 um, and a silver content of 5%-15%.

[0033] In the above, the wire diameter of the nanosilver wires refers to the diameter of a single silver wire. The size range ensures that the silver wires have a sufficient specific surface area to form a conductive joint while avoiding an abnormal increase in the viscosity of the paste caused by an excessively large wire diameter. The wire length refers to the extension length of a single silver wire. The length range ensures that the silver wires remain stably dispersed in the solvent while forming a three-dimensional conductive network through staggered arrangement. The silver content refers to the mass ratio of the nanosilver wires in the conductive paste, which can be achieved by adjusting the ratio of the amount of silver wires to the resin matrix. The content range maintains the flexibility and adhesion strength of the paste system while ensuring the conductive performance. Specifically, the wire diameter of the nanosilver wires is, for example, 10 nm, 20 nm, 30 nm, or 40 nm. The wire length of the nanosilver wires is, for example, 10 um, 20 um, 30 um, 40 um, 50 um, 60 um, 70 um, 80 um, 90 um, or 100 um.

[0034] By the above technical solution, the wire diameter, the wire length, and the silver content of the nanosilver wires are set within a certain range, so that the nanosilver wires have a large aspect ratio, and the wire diameter of the nanosilver wires is small. The larger the aspect ratio (the ratio of the wire length to the wire diameter) of the nanosilver wires, the better the conductivity of the nanosilver wires, and the smaller the wire diameter of the nanosilver wires, the better the bending performance and flexibility of the nanosilver wires. In particular, the wire diameter is 10-40 nm, the wire length is 10-50 um, and the silver content is 5%-15%. The large aspect ratio ensures a resistivity of less than 1*10-6Ωm.

[0035] In some embodiments, the conductive paste is sprayed on the elastic wave by air pressure spraying, the air pressure of the spray gun is controlled to be 0.1-0.2 MPa, and the thickness of the conductive wet film layer formed by each application of the conductive paste is 10 um-100 um.

[0036] The thickness uniformity of the conductive paste needs to be controlled not only by the solid content and viscosity of the conductive paste, but also by the spraying speed, spraying pressure, spraying times, and nozzle size. The spraying speed should be set within a reasonable range. If the spraying speed is too slow, ink overflow is likely to occur, the appearance is not good, and bubbles are likely to occur during drying. If the spraying speed is too fast, the coating is thin and the resistance is high. In the present application, preferably, the spraying speed is in the range of 10 mm / s to 50 mm / s, for example, 10 mm / s, 15 mm / s, 20 mm / s, 25 mm / s, 30 mm / s, 35 mm / s, 40 mm / s, 45 mm / s, or 50 mm / s. The spraying pressure is determined according to the liquid output and the appearance of the spraying. If the liquid output is low, the spraying efficiency is low, and if the liquid output is high, the appearance is not good. In the present embodiment, the spraying pressure is in the range of 0.1 MPa to 0.2 MPa, for example, 0.1 MPa or 0.2 MPa. The nozzle size should be set within a suitable range, for example, the diameter of the nozzle is between 0.25 and 0.35 mm, and the surface state is good without bubbles.

[0037] The thickness of the conductive wet film refers to the thickness range of the uncured paste layer of a single coating. The thickness of the conductive paste is controlled by controlling the single spraying amount of the conductive paste. Specifically, if the single spraying thickness is thin, the resistance is low, multiple spraying is required, and the efficiency is low. If the single spraying thickness is thick, the film is likely to overflow, the appearance is not good, and bubbles are likely to occur during drying. Controlling the single spraying thickness of the conductive paste within a certain range can improve the appearance of the conductive layer while ensuring the resistance and spraying efficiency. Specifically, the thickness of the conductive paste applied at a time is 10 um, 15 um, 20 um, 25 um, 30 um, 35 um, 40 um, 45 um, 50 um, 55 um, 60 um, 65 um, 70 um, 75 um, 80 um, 85 um, 90 um, 95 um, or 100 um.

[0038] By the above technical solution, air pressure spraying is adopted, the spraying air pressure is set within a certain range, and the thickness of the single spraying conductive wet film is set within a certain range, which can ensure the thickness uniformity of the conductive paste after spraying of the water-based solvent system.

[0039] In some embodiments, the conductive paste can also be applied to the surface of the elastic wave in the form of ultrasonic spraying, electrostatic spraying, dispensing, or printing. Details are not described here.

[0040] In some embodiments, the total thickness of the multiple layers of conductive wet film formed by multiple applications of the conductive paste after high-temperature curing is not greater than 50 um.

[0041] The plurality of conductive wet film layers formed by applying the conductive paste multiple times is cured at high temperature to form the conductive layer 2. The thickness of the conductive layer 2 can be controlled by controlling the total amount of the conductive paste applied. Specifically, the thickness of the conductive layer 2 can be 20 μm, 30 μm, 40 μm, or 50 μm.

[0042] By limiting the total thickness of the conductive layer after curing within a certain range, the stress concentration caused by the excessive thickness of the adhesive layer can be avoided.

[0043] In some embodiments, a mask is applied to the surface of the elastic wave 1 when the conductive paste is applied. The mask has a hollow pattern that matches the shape of the conductive layer 2, and the conductive paste is applied to the hollow pattern of the mask.

[0044] In the above, the mask refers to a physical shielding structure applied to the surface of the elastic wave 1, and the hollow pattern refers to the opening area designed on the mask. The shape of the hollow area completely matches the distribution of the target conductive layer 2. This structure limits the flow range of the conductive paste through physical confinement to prevent the conductive paste from spreading outside the predetermined range.

[0045] Specifically, after the mask is applied to the surface of the elastic wave 1, the conductive paste is deposited in the hollow area. When the conductive paste is applied, the conductive paste can only be attached to the surface of the elastic wave 1 through the hollow part, and the paste coverage area of the wave peak and wave valley area is evenly distributed through the size design of the hollow pattern.

[0046] By the above technical solution, the mask is set to ensure that the conductive layer formed has a good topography.

[0047] In some embodiments, when the conductive wet film layer is cured, the entire elastic wave with the conductive wet film layer is sent into an oven for baking and curing.

[0048] In the above, the oven is a device that controls the heating environment to dry, cure, heat treat, sterilize, and other processing or experimental operations of materials. Its core function is to generate heat using electric energy, gas, and other energy sources, and to form a controllable high-temperature environment in a closed or semi-closed cavity, thereby changing the physical or chemical properties of the material.

[0049] By the above technical solution, the oven is used to cure the conductive wet film layer, which has the advantages of controllable temperature, uniform heating, high efficiency, and good safety.

[0050] After the upper conductive elastic wave is made, the resistance of the conductive elastic wave is tested by the following method.

[0051] The test method of the conductive elastic wave includes the following steps: S21, measuring the resistance of the conductive layer, the resistance between each adjacent peak conductive part of the conductive layer, and the resistance between each adjacent valley conductive part of the conductive layer; S22, calculating the difference rate of the resistance of the conductive layer and the target resistance, the difference rate of the resistance between each adjacent peak conductive part of the conductive layer and the average resistance of all adjacent peak conductive parts, and the difference rate of the resistance between each adjacent valley conductive part of the conductive layer and the average resistance of all adjacent valley conductive parts; S23, determining whether all the following conditions are met: the difference rate of the resistance of the conductive layer and the target resistance is less than a first set value, the difference rate of the resistance between each group of adjacent peak conductive parts of the conductive layer and the average resistance of all adjacent peak conductive parts is less than a second set value, and the difference rate of the resistance between each group of adjacent valley conductive parts of the conductive layer and the average resistance of all adjacent valley conductive parts is less than a second set value. If so, the conductive spring is qualified, and if not, the conductive spring is unqualified.

[0052] In the above, by detecting the resistance and resistance uniformity of the conductive layer, it can be determined whether the conductive spring is qualified, which can reflect the true conductive performance of the conductive spring.

[0053] A loudspeaker is introduced below, which includes the above-mentioned conductive spring. The loudspeaker, commonly known as "loudspeaker", is an electroacoustic transducer that converts electrical signals into acoustic signals. It is widely used in sound-producing electronic and electrical equipment, such as public address systems, radio or television receivers, and record players. The working principle of the loudspeaker is similar to that of the telephone receiver. Through electromagnetic, piezoelectric or electrostatic effect, the cone or diaphragm vibrates the surrounding air, thereby producing sound. Specifically, when an electric current passes through the loudspeaker, a magnetic field is generated, which interacts with the fixed permanent magnet, causing the vibrating diaphragm to produce mechanical vibration, which in turn causes the air to vibrate and emit sound. The loudspeaker is an important component in sound equipment, although it is the weakest device in electronic equipment, but it is crucial to the sound quality. There are many types of loudspeakers, with great price differences, from built-in loudspeakers to external sound boxes, widely used in various electronic devices such as MP4 players, televisions, computers, etc.

[0054] Embodiment 1: The manufacturing method of the conductive spring includes the following steps: First, prepare the following raw materials by weight: Polyether polyurethane resin 2 parts Nano silver wire dispersion liquid (silver content 12%) 10 parts Hydroxypropyl methylcellulose 0.03 parts Leveling agent BYK-333 0.01 parts Dispersant DISPERBYK-110 0.01 parts Water 6 parts Second step, in 6 parts of water, add 2 parts of polyether polyurethane resin, high speed stirring dissolving; Then add 0.01 parts of leveling agent BYK-333, 0.01 parts of dispersant DISPERBYK-110, 0.03 parts of hydroxypropyl methyl cellulose, fully stirred uniform; Then add 10 parts of silver content of 12% of nanosilver line dispersion liquid (wire diameter 25-30nm, wire length 24-28um), stirring uniform; The mixed slurry is stirred with double planetary mixer, ground by three roll mill, and then high speed dispersion and defoaming, the final conductive silver glue is obtained, the viscosity of the conductive silver paste is 230mPas-250mPas, the elongation rate is greater than 20%, the resistivity is 2*10 -6 Ωm; Third step, the mask prepared according to the spraying shape is placed on the elastic wave, and the conductive silver glue is sprayed on the elastic wave substrate by air pressure spraying, the spraying speed is 20mm / s, the spraying pressure is 0.2MPa, the wet film thickness of single spraying is 70um, the spraying times is 4 times, the nozzle diameter is 0.3mm, and the elastic wave is put into the oven after each spraying, the first three times are low temperature curing, the temperature of low temperature curing is 80℃, and the time is 5min, the last time is post curing, the temperature of post curing is 120℃, and the time is 30min, the width of the conductive layer is 3mm, the length is 15mm, and the amplitude is 1.7mm (the vertical distance between the wave crest and the wave trough is 1.2-2.0mm).

[0055] Fourth step, the resistance parameter test of the obtained conductive elastic wave is carried out.

[0056] The resistance and resistance average value between each wave crest conductive part A1, A2, A3 and A4, and the resistance and resistance average value between each wave trough conductive part B1, B2 and B3 are listed in the following table. Figure 2

[0057] The resistance average value RA between all adjacent wave crest conductive parts of the conductive layer AV = (RA1+RA2+RA3) / 3; The resistance average value RB of all adjacent wave trough conductive parts of the conductive layer AV = (RB1+RB2) / 2; From the table, it can be calculated that the resistance of the conductive layer is within 0.1 ohm, which can ensure that the conductive layer has good conductivity, the difference rate between the test resistance of the conductive layer and the target resistance is 1.79%, the difference rate between the resistance and the resistance average value of adjacent wave crest and wave crest is within 10%, and the difference rate between the resistance and the resistance average value of adjacent wave trough and wave trough is within 10%, which can ensure that the conductive layers have good thickness uniformity and resistance uniformity.

[0058] ​Obviously, the above embodiments are merely example for clearly illustrating, and are not limitation to the embodiments. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments need not and can not be exhausted. The obvious changes or variations derived therefrom are still within the scope of the present invention.

Claims

1. A method for manufacturing a conductive spool, characterized in that, Includes the following steps: A conductive slurry with a viscosity of 100-1000 mPas is applied to the spar to form a conductive wet film layer. The formed conductive wet film layer is cured; Repeat the above steps at least once; When performing the above steps for the first time or later, the conductive wet film layer is cured at a low temperature of 60-80℃ for 5-10 minutes. When performing the above steps for the first time, apply the conductive paste to the surface of the existing low-temperature cured conductive wet film layer; When performing the above steps for the last time, the conductive wet film layer is cured at a high temperature of 100-120℃ for 30-60 minutes to obtain a conductive elastic wave.

2. The method for manufacturing a conductive spindle according to claim 1, characterized in that, The conductive paste comprises the following components in weight percentage: 3%-10% polyurethane resin, 5%-10% silver nanowires, 0.2%-1% thickener, 0.1%-3% dispersant, 0.1%-0.5% leveling agent, and 70%-85% solvent.

3. The method for manufacturing a conductive spindle according to claim 2, characterized in that, The diameter of the silver nanowires is between 10-40 nm, the length is between 10-50 μm, and the silver content is between 5%-15%.

4. The method for manufacturing a conductive spool according to claim 2, characterized in that, The conductive paste is sprayed onto the spinneret using air pressure spraying. The air pressure of the spray gun is controlled at 0.1-0.2MPa, and the thickness of the conductive wet film applied each time ranges from 10μm to 100μm.

5. The method for manufacturing a conductive spool according to claim 4, characterized in that, The thickness of the conductive wet film obtained by each application of conductive slurry ranges from 15 to 20 μm.

6. The method for manufacturing a conductive spindle according to claim 1, characterized in that, The total thickness of the multilayer conductive wet film obtained by applying conductive slurry multiple times after high-temperature curing is no more than 50 μm.

7. The method for manufacturing a conductive spool according to claim 1, characterized in that, When applying the conductive paste, a mask is placed over the surface of the elastic wave; the mask has a perforated pattern adapted to the shape of the conductive wet film layer, and the conductive paste is applied to the perforated pattern of the mask.

8. The method for manufacturing a conductive spindle according to claim 1, characterized in that, When curing the conductive wet film layer, the entire slab bearing the conductive wet film layer is placed into an oven for baking and curing.

9. A conductive elastic wave, characterized in that, It is manufactured using the manufacturing method described in any one of claims 1 to 8.

10. A loudspeaker comprising the conductive spring wave of claim 9.

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