PVDF sound production thin film assembly and preparation method and application thereof

Abstract

The invention belongs to the technical field of acoustic materials and loudspeakers, and provides a PVDF sound production thin film assembly and a preparation method and application thereof, and the PVDF sound production thin film assembly comprises an electrode layer, a protection layer and a grid supporting layer which are sequentially arranged on the two sides of a PVDF layer. By arranging the grid supporting layer, the grid supporting layer can provide appropriate supporting and mechanical buffering effects, when the assembly is used in an attached mode, it can be guaranteed that certain spaces are still reserved on the two sides of the PVDF layer, it is guaranteed that gas in the spaces can vibrate along with the PVDF layer, and therefore sound production is not affected.

Description

Technical Field

[0001] The invention belongs to the technical field of acoustic materials and loudspeakers, and relates to a PVDF sound-generating film component and a preparation method and application thereof. Background Art

[0002] With the rapid development of information technology, people's demands for audio equipment are becoming increasingly diversified, and the performance requirements for audio equipment are also getting higher and higher. Polyvinylidene fluoride (PVDF) is a high-performance polymer material that has been widely used in many fields due to its unique physical and chemical properties. In the field of audio equipment, PVDF film has become an ideal material for the new generation of film speakers due to its excellent piezoelectric properties and inverse piezoelectric effect.

[0003] PVDF is a semi-high molecular polymer material. The film prepared by stretching and polarization will have strong piezoelectricity, that is, when pressure is applied to its surface, the molecular structure of the material will change, causing the position of the charge to shift, so that the macroscopic manifestation is the transformation of mechanical signals into electrical signals. Similarly, it can also show the reverse piezoelectric effect, that is, when electrical signals are applied to both sides of the PVDF film material, the film will have a certain deformation, which is manifested in the macroscopic transformation of electrical signals into mechanical signals.

[0004] The working principle of PVDF film speakers is based on the inverse piezoelectric effect of the material. Specifically, PVDF film speakers convert audio signals into electrical signals, amplify the signals with an amplifier, and then apply the amplified electrical signals to the two sides of the PVDF film. In this case, the film will change accordingly according to the strength and frequency of the electrical signal, thereby causing the film to vibrate and emit sound. Since the PVDF material itself has a high sensitivity, only a small driving voltage is required to achieve a large amplitude output, making the PVDF film speaker have a good response characteristic.

[0005] Compared with traditional speakers, PVDF film speakers have the advantages of simple structure, light weight, wide bandwidth, good transient, large dynamic range, low distortion and directional sound. However, there are also some limitations in practical applications. The main problem is that traditional PVDF film speakers need to reserve enough space on the film or on both sides of the film for the film to vibrate during installation, otherwise it will affect its sound effect. This means that in some application scenarios that require compact design or limited space, such as smart wearable devices, mobile terminals and other devices, it is difficult to provide enough vibration space for PVDF film speakers, or the vibration space is lost due to the need for attachment, so that it cannot effectively and normally sound, limiting its wide application in these fields.

[0006] In view of the above problems, it is particularly necessary to develop a new PVDF sound-generating film technology solution to overcome the limitations of traditional PVDF film speakers in installation and use, so that it can be promoted in more application scenarios. Summary of the invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a PVDF sound-generating film component and its preparation method and application, wherein the PVDF sound-generating film component comprises an electrode layer, a protective layer and a mesh support layer sequentially arranged on both sides of a PVDF layer. The present invention provides a mesh support layer so that the mesh support layer can provide appropriate support and mechanical buffering. When the component is attached and used, it can ensure that a certain space is still reserved on both sides of the PVDF layer, and ensure that the gas in these spaces can vibrate with the PVDF layer, thereby not affecting the sound generation.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a PVDF sound-emitting film assembly, comprising an electrode layer, a protective layer and a grid support layer sequentially arranged on both sides of a PVDF layer.

[0010] The PVDF piezoelectric film (PVDF layer) will vibrate and make sounds when electrified, and different frequencies produce different tones. However, people cannot hear the sound just by the vibration of the film, and air conduction is also required. For this reason, if the film is pressed against the surface of other objects, the film loses its space for vibration and cannot vibrate and make sounds normally. However, the present invention sets a specific grid support layer. Since the grid support layer has a certain thickness and the hollow holes have a certain area, each hollow hole can form a separate space in the thickness direction, thereby vibrating and making sounds independently. Therefore, when this side is used for attachment, it can effectively provide a space (thickness) for free vibration, thereby ensuring the normal vibration and sound-making function and effect of the PVDF layer.

[0011] The following are preferred technical solutions of the present invention, but are not intended to be limitations of the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] As a preferred technical solution of the present invention, the thickness of the grid support layer is 10 to 500 μm, for example, 5 μm, 8 μm, 10 μm, 15 μm, 20 μm, 35 μm, 50 μm, 75 μm, 90 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, 320 μm, 340 μm, 360 μm, 380 μm, 400 μm, 420 μm, 440 μm, 460 μm, 480 μm or 500 μm, etc., but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0013] Preferably, the material of the grid support layer includes at least one of epoxy resin glue, UV glue or PLA material.

[0014] In the present invention, the grid support layer has a certain strength, so it can be screen-printed or pasted in the form of epoxy resin glue, UV glue, etc., and can also be further 3D printed using PLA (polylactic acid) materials, etc.

[0015] Preferably, the hollow holes of the grid support layer are arranged in an array.

[0016] That is, the hollow holes in the grid support layer of the present invention are preferably arranged regularly.

[0017] Preferably, the shapes of the hollow holes of the grid support layer include polygonal and / or circular shapes, and the polygonal shapes include triangles, squares, pentagons or hexagons, etc.

[0018] Preferably, the area occupied by the hollow holes of each grid support layer is 0.01 to 8 mm. 2 , for example 0.01mm 2 , 0.05mm 2 、0.08mm 2 , 0.1mm 2 , 0.2mm 2 , 0.3mm 2 , 0.5mm 2 , 0.8mm 2 , 1mm 2 , 1.5mm 2 , 2mm 2 , 2.5mm 2 , 3mm 2 , 3.5mm 2 , 4mm 2 , 4.5mm 2 , 5mm 2 , 5.5mm 2 、6mm2 、6.5mm 2 , 7mm 2 , 7.5mm 2 or 8mm 2 etc., but are not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0019] As a preferred technical solution of the present invention, the thickness of the PVDF layer is 5 to 500 μm, for example, 5 μm, 8 μm, 10 μm, 15 μm, 20 μm, 35 μm, 50 μm, 75 μm, 90 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, 320 μm, 340 μm, 360 μm, 380 μm, 400 μm, 420 μm, 440 μm, 460 μm, 480 μm or 500 μm, etc., but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0020] As a preferred technical solution of the present invention, the electrode layer includes at least one of PEDOT:PSS, nanosilver wires, indium tin oxide or conductive silver paste.

[0021] Preferably, the thickness of the electrode layer is 0.6-1 μm, for example 0.6 μm, 0.65 μm, 0.7 μm, 0.75 μm, 0.8 μm, 0.85 μm, 0.9 μm, 0.95 μm or 1 μm, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0022] As a preferred technical solution of the present invention, the PVDF sound-emitting film assembly further includes a silver paste layer, and the silver paste layer is arranged between the electrode layer and the protective layer.

[0023] Preferably, the thickness of the silver paste layer is 5 to 15 μm, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm or 15 μm, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0024] Preferably, the silver paste layer is disposed on one side of the electrode layer close to the protective layer and along four sides of the surface to form a frame-shaped silver paste layer.

[0025] In the present invention, the silver paste layer can improve the conductive effect and is used to support external wires to achieve external connection.

[0026] Preferably, the electrode layer is provided with a pin portion, and the silver paste layer covers the pin portion.

[0027] Preferably, a double-sided conductive copper tape is provided on the silver paste layer at the pin position.

[0028] In the present invention, pasting double-sided conductive copper tape on the pin portion of the electrode layer can prevent the silver paste layer from being oxidized and scratched, and can also be used for welding external wires.

[0029] As a preferred technical solution of the present invention, the protective layer includes a PET film.

[0030] Preferably, the thickness of the protective layer is 30 to 80 μm, for example, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm or 80 μm, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0031] In the present invention, the presence of the protective layer can protect the internal stability and play an insulating effect.

[0032] In a second aspect, the present invention provides a method for preparing the PVDF sound-emitting film assembly according to the first aspect, the method comprising:

[0033] (1) providing a first protective layer, and forming a first electrode layer on one side of the first protective layer to obtain a first composite; providing a second protective layer, and forming a second electrode layer on one side of the second protective layer to obtain a second composite;

[0034] (2) forming a PVDF initial film on the first electrode layer of the first composite body, and performing a first baking on the PVDF initial film to make the PVDF initial film sticky, thereby obtaining a third composite body;

[0035] (3) pressing and laminating the second electrode layer in the second composite onto the PVDF initial film of the third composite, and performing a second baking to solidify the PVDF initial film into a PVDF layer, thereby obtaining a fourth composite;

[0036] (4) A first mesh support layer and a second mesh support layer are formed on the first protective layer and the second protective layer in the fourth composite body, respectively.

[0037] In the preparation method of the present invention, the PVDF initial film is first baked to make it sticky, so that the second composite can be pasted to form a third composite, and then the crystallinity is increased and solidified by a second baking to form a PVDF layer.

[0038] As a preferred technical solution of the present invention, step (1) includes providing a first protective layer, and sequentially stacking a first silver paste layer and a first electrode layer on one side of the first protective layer to obtain a first composite; providing a second protective layer, and sequentially stacking a second silver paste layer and a second electrode layer on one side of the second protective layer to obtain a second composite.

[0039] Preferably, in step (1), the method for forming the first silver paste layer and the second silver paste layer includes first performing screen printing with a mesh size of 200 to 300, such as 200 mesh, 210 mesh, 220 mesh, 230 mesh, 240 mesh, 250 mesh, 260 mesh, 270 mesh, 280 mesh, 290 mesh or 300 mesh, and then performing a third baking at 100 to 140°C, such as 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C or 140°C, for 20 to 40 minutes, such as 20 minutes, 23 minutes, 25 minutes, 28 minutes, 30 minutes, 33 minutes, 35 minutes, 38 minutes or 40 minutes, but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0040] Preferably, in step (1), the method for forming the electrode layer comprises first performing screen printing of 280 to 320 meshes, for example, 280 mesh, 290 mesh, 300 mesh, 310 mesh or 320 mesh, or first performing at least one of inkjet printing, mask coating or magnetron sputtering, and then performing a fourth baking at 100 to 140°C, for example, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C or 140°C, for 10 to 20 minutes, for example, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes or 20 minutes, but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0041] Preferably, in step (4), the method of forming the grid support layer includes at least one of glue dispensing, 3D printing or 80-120 mesh screen printing, for example, 80 mesh, 85 mesh, 90 mesh, 95 mesh, 100 mesh, 105 mesh, 110 mesh, 115 mesh or 120 mesh, etc., but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0042] As a preferred technical solution of the present invention, in step (2), the method for forming the PVDF initial membrane includes: mixing a PVDF raw material with a solvent to prepare a PVDF precursor solution, and coating and / or casting the PVDF precursor solution to obtain a PVDF initial membrane.

[0043] In the present invention, a commercially available PVDF film may be directly disposed on the first electrode layer, and bonded to the first electrode layer through a first baking process to obtain a first composite.

[0044] Preferably, the solvent comprises N,N-dimethylformamide.

[0045] Preferably, before use, the PVDF precursor solution is filtered using a mesh of 300 to 500 mesh, such as 300 mesh, 320 mesh, 340 mesh, 360 mesh, 380 mesh, 400 mesh, 420 mesh, 440 mesh, 460 mesh, 480 mesh or 500 mesh, etc., but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0046] Preferably, in the PVDF precursor solution, the mass ratio of the PVDF raw material to the solvent is 1:(5-20), for example 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20, etc., but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0047] Preferably, the preparation temperature of the PVDF precursor solution is 60-80°C, for example, 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0048] Preferably, the first baking temperature is 70-90° C., for example, 70° C., 72° C., 74° C., 76° C., 78° C., 80° C., 82° C., 84° C., 86° C., 88° C. or 90° C., and the baking time is 1-3 h, for example, 1 h, 1.2 h, 1.4 h, 1.6 h, 1.8 h, 2 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h or 3 h,

[0049] Preferably, the second baking temperature is 100-120°C, for example, 100°C, 105°C, 110°C, 115°C or 120°C, and the time is 1-2h, for example, 1h, 1.2h, 1.4h, 1.6h, 1.8h or 2h, but is not limited to the listed values, and other unlisted values ​​within the above numerical range are also applicable.

[0050] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0051] The present invention sets a grid support layer so that the grid support layer can provide appropriate support and mechanical buffering. When the component is attached and used, since the grid support layer has a certain thickness and the hollow holes have a certain area, each hollow hole can form a separate space in the thickness direction, which can ensure that the gas in these spaces can vibrate with the PVDF layer, thereby not affecting the sound. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic structural diagram of the PVDF sound-generating film assembly of Example 1;

[0053] Figure 2 is a schematic diagram of a grid support layer of Example 1;

[0054] Figure 3 is a schematic diagram of a grid support layer of Example 2;

[0055] Figure 4 is a schematic diagram of a grid support layer of Example 3;

[0056] In the figure: 1-PVDF layer, 2-first electrode layer, 3-first silver paste layer, 4-first protective layer, 5-first grid support layer, 6-second electrode layer, 7-second silver paste layer, 8-second protective layer, 9-second grid support layer. DETAILED DESCRIPTION

[0057] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0058] It should be clear to those skilled in the art that the embodiments are only intended to help understand the present invention and should not be considered as specific limitations of the present invention.

[0059] Example 1

[0060] This embodiment provides a PVDF sound-generating film assembly, such as Figure 1 As shown, it includes a PVDF layer 1, and a first electrode layer 2, a first silver paste layer 3, a first protective layer 4 and a first grid support layer 5 stacked in sequence on one side of the PVDF layer 1; and also includes a second electrode layer 6, a second silver paste layer 7, a second protective layer 8 and a second grid support layer 9 stacked in sequence on the other side of the PVDF layer 1;

[0061] The thickness of the PVDF layer 1 is 300 μm;

[0062] The first electrode layer 2 and the second electrode layer 6 are made of PEDOT:PSS, and both have a thickness of 0.8 μm; the first electrode layer 2 and the second electrode layer 6 are both provided with pin portions;

[0063] The first silver paste layer 3 and the second silver paste layer 7 are respectively arranged around the surfaces of the first electrode layer 2 and the second electrode layer 6 to form a frame-shaped silver paste layer; the first silver paste layer 3 and the second silver paste layer 7 both cover the corresponding pin parts; the thickness of the first silver paste layer 3 and the second silver paste layer 7 is 10 μm; the first silver paste layer 3 and the second silver paste layer 7 at the pin parts are both provided with double-sided conductive copper tape;

[0064] The first protective layer 4 and the second protective layer 8 are both PET films with a thickness of 50 μm.

[0065] The first grid support layer 5 and the second grid support layer 9 are both made of UV glue, and the thickness is 50 μm. Figure 2 As shown, the shape of the hollow holes of the grid support layer is a square, and the hollow holes are arranged in an array with a diagonal line of the square parallel to the length side of the grid support layer; the shape of each hollow hole occupies an area of ​​4mm 2 ; and the thickness of the grid support layer is 200μm.

[0066] The preparation method of the PVDF sound-generating film assembly comprises:

[0067] (1) providing a first protective layer 4, and sequentially stacking a first silver paste layer 3 and a first electrode layer 2 on one side of the first protective layer 4 to obtain a first composite; providing a second protective layer 8, and sequentially stacking a second silver paste layer 7 and a second electrode layer 6 on one side of the second protective layer 8 to obtain a second composite;

[0068] The method of forming the first silver paste layer 3 and the second silver paste layer 7 comprises firstly performing 250 mesh screen printing, and then performing a third baking at 120° C. for 30 minutes;

[0069] The method of forming the first electrode layer 2 and the second electrode layer 6 includes first performing 300-mesh screen printing, and then performing a fourth baking at 120° C. for 15 minutes;

[0070] (2) forming a PVDF initial film on the first electrode layer 2 of the first composite, and performing a first baking on the PVDF initial film at 70° C. for 1 h to make the PVDF initial film sticky, thereby obtaining a third composite;

[0071] The method for forming the PVDF initial membrane comprises: mixing a PVDF raw material and a solvent N,N-dimethylformamide at a mass ratio of 1:15, preparing a PVDF precursor solution at 70° C., filtering the PVDF precursor solution with a 400-mesh gauze, and spin coating the PVDF precursor solution to obtain a PVDF initial membrane;

[0072] (3) Pressing and laminating the second electrode layer 6 in the second composite onto the PVDF initial film of the third composite, and performing a second baking at 120° C. for 2 h to solidify the PVDF initial film into a PVDF layer 1, thereby obtaining a fourth composite;

[0073] (4) UV glue with a mesh size of 100 is respectively printed on the first protective layer 4 and the second protective layer 8 in the fourth composite body. After the UV glue is cured by a UV lamp, a first grid support layer 5 and a second grid support layer 9 are formed to obtain the PVDF sound-emitting film assembly.

[0074] Example 2

[0075] This embodiment provides a PVDF sound-emitting film assembly, comprising a PVDF layer 1, and a first electrode layer 2, a first silver paste layer 3, a first protective layer 4, and a first mesh support layer 5 stacked in sequence on one side of the PVDF layer 1; and further comprising a second electrode layer 6, a second silver paste layer 7, a second protective layer 8, and a second mesh support layer 9 stacked in sequence on the other side of the PVDF layer 1;

[0076] The thickness of the PVDF layer 1 is 20 μm;

[0077] The first electrode layer 2 and the second electrode layer 6 are nano silver wires, each with a thickness of 0.6 μm; the first electrode layer 2 and the second electrode layer 6 are both provided with pin portions;

[0078] The first silver paste layer 3 and the second silver paste layer 7 are respectively arranged around the surfaces of the first electrode layer 2 and the second electrode layer 6 to form a frame-shaped silver paste layer; the first silver paste layer 3 and the second silver paste layer 7 both cover the corresponding pin parts; the thickness of the first silver paste layer 3 and the second silver paste layer 7 is 5 μm; the first silver paste layer 3 and the second silver paste layer 7 at the pin parts are both provided with double-sided conductive copper tape;

[0079] The first protective layer 4 and the second protective layer 8 are both PET films with a thickness of 30 μm.

[0080] The first grid support layer 5 and the second grid support layer 9 are both made of epoxy resin glue, and the thickness is 10 μm; Figure 3 As shown, the shape of the hollow holes of the grid support layer is a square, and the hollow holes are arranged in an array with one side of the square parallel to the length side of the grid support layer; the shape of each hollow hole occupies an area of ​​0.08mm 2 ; and the thickness of the grid support layer is 15μm.

[0081] The preparation method of the PVDF sound-generating film assembly comprises:

[0082] (1) providing a first protective layer 4, and sequentially stacking a first silver paste layer 3 and a first electrode layer 2 on one side of the first protective layer 4 to obtain a first composite; providing a second protective layer 8, and sequentially stacking a second silver paste layer 7 and a second electrode layer 6 on one side of the second protective layer 8 to obtain a second composite;

[0083] The method of forming the first silver paste layer 3 and the second silver paste layer 7 includes firstly performing 300 mesh screen printing, and then performing a third baking at 100° C. for 40 minutes;

[0084] The method of forming the first electrode layer 2 and the second electrode layer 6 includes first performing 320-mesh screen printing, and then performing a fourth baking at 100° C. for 20 minutes;

[0085] (2) forming a PVDF initial film on the first electrode layer 2 of the first composite, and performing a first baking on the PVDF initial film at 90° C. for 3 h to make the PVDF initial film sticky, thereby obtaining a third composite;

[0086] The method for forming the PVDF initial membrane comprises: mixing a PVDF raw material and a solvent N,N-dimethylformamide at a mass ratio of 1:5 to prepare a PVDF precursor solution at 60° C., filtering the PVDF precursor solution with a 500-mesh gauze, and spin coating the PVDF precursor solution to obtain a PVDF initial membrane;

[0087] (3) pressing and laminating the second electrode layer 6 in the second composite onto the PVDF initial film of the third composite, and performing a second baking at 100° C. for 2 h to solidify the PVDF initial film into a PVDF layer 1, thereby obtaining a fourth composite;

[0088] (4) UV glue with a mesh size of 100 is respectively printed on the first protective layer 4 and the second protective layer 8 in the fourth composite body. After the UV glue is cured by a UV lamp, a first grid support layer 5 and a second grid support layer 9 are formed to obtain the PVDF sound-emitting film assembly.

[0089] Example 3

[0090] This embodiment provides a PVDF sound-emitting film assembly, comprising a PVDF layer 1, and a first electrode layer 2, a first silver paste layer 3, a first protective layer 4, and a first mesh support layer 5 stacked in sequence on one side of the PVDF layer 1; and further comprising a second electrode layer 6, a second silver paste layer 7, a second protective layer 8, and a second mesh support layer 9 stacked in sequence on the other side of the PVDF layer 1;

[0091] The thickness of the PVDF layer 1 is 420 μm;

[0092] The first electrode layer 2 and the second electrode layer 6 are made of indium tin oxide, and both have a thickness of 1 μm; the first electrode layer 2 and the second electrode layer 6 are both provided with pin portions;

[0093] The first silver paste layer 3 and the second silver paste layer 7 are respectively arranged around the surfaces of the first electrode layer 2 and the second electrode layer 6 to form a frame-shaped silver paste layer; the first silver paste layer 3 and the second silver paste layer 7 both cover the corresponding pin parts; the thickness of the first silver paste layer 3 and the second silver paste layer 7 is 15 μm; the first silver paste layer 3 and the second silver paste layer 7 at the pin parts are both provided with double-sided conductive copper tape;

[0094] The first protective layer 4 and the second protective layer 8 are both PET films with a thickness of 80 μm.

[0095] The first grid support layer 5 and the second grid support layer 9 are both made of PLA material, and the thickness is 450 μm. Figure 4 As shown, the shape of the hollow holes of the grid support layer is an equilateral triangle, and the hollow holes are arranged in an array with one side of the equilateral triangle parallel to the length side of the grid support layer; the shape of each hollow hole occupies an area of ​​8mm 2 ; and the thickness of the grid support layer is 450μm.

[0096] The preparation method of the PVDF sound-generating film assembly comprises:

[0097] (1) providing a first protective layer 4, and sequentially stacking a first silver paste layer 3 and a first electrode layer 2 on one side of the first protective layer 4 to obtain a first composite; providing a second protective layer 8, and sequentially stacking a second silver paste layer 7 and a second electrode layer 6 on one side of the second protective layer 8 to obtain a second composite;

[0098] The method of forming the first silver paste layer 3 and the second silver paste layer 7 includes firstly performing 200 mesh screen printing, and then performing a third baking at 140° C. for 20 minutes;

[0099] The method of forming the first electrode layer 2 and the second electrode layer 6 includes first performing 280 mesh screen printing, and then performing a fourth baking at 140° C. for 10 minutes;

[0100] (2) forming a PVDF initial film on the first electrode layer 2 of the first composite, and performing a first baking on the PVDF initial film at 80° C. for 2 h to make the PVDF initial film sticky, thereby obtaining a third composite;

[0101] The method for forming the PVDF initial membrane comprises: mixing a PVDF raw material and a solvent N,N-dimethylformamide at a mass ratio of 1:20, preparing a PVDF precursor solution at 80° C., filtering the PVDF precursor solution with a 300-mesh gauze, and spin coating the PVDF precursor solution to obtain a PVDF initial membrane;

[0102] (3) Pressing and laminating the second electrode layer 6 in the second composite onto the PVDF initial film of the third composite, and performing a second baking at 110° C. for 2 h to solidify the PVDF initial film into a PVDF layer 1, thereby obtaining a fourth composite;

[0103] (4) Forming a first mesh support layer 5 and a second mesh support layer 9 on the first protective layer 4 and the second protective layer 8 in the fourth composite by 3D printing PLA material, respectively, to obtain the PVDF sound-emitting film assembly.

[0104] Example 4

[0105] This embodiment provides a PVDF sound-emitting film assembly, in which the thickness of the first mesh support layer 5 and the second mesh support layer 9 is adjusted from 200 μm to 5 μm. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0106] Example 5

[0107] This embodiment provides a PVDF sound-emitting film assembly, in which the thickness of the first grid support layer 5 and the second grid support layer 9 is adjusted from 200 μm to 10 μm. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0108] Example 6

[0109] This embodiment provides a PVDF sound-emitting film assembly, in which the thickness of the first grid support layer 5 and the second grid support layer 9 is adjusted from 200 μm to 500 μm. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0110] Example 7

[0111] This embodiment provides a PVDF sound-emitting film assembly, in which the thickness of the first grid support layer 5 and the second grid support layer 9 is adjusted from 200 μm to 550 μm. Except for the above, other conditions are exactly the same as those in Embodiment 1.

[0112] Example 8

[0113] This embodiment provides a PVDF sound-generating film assembly, wherein the area occupied by each hollow hole of the first grid support layer 5 and the second grid support layer 9 is changed from 4 mm 2 Adjust to 0.01mm 2 , except for the above, other conditions are the same as those of Complete Example 1.

[0114] Example 9

[0115] This embodiment provides a PVDF sound-generating film assembly, wherein the area occupied by each hollow hole of the first grid support layer 5 and the second grid support layer 9 is changed from 4 mm 2 Adjust to 1mm 2 , except for the above, other conditions are the same as those of Complete Example 1.

[0116] Example 10

[0117] This embodiment provides a PVDF sound-generating film assembly, wherein the area occupied by each hollow hole of the first grid support layer 5 and the second grid support layer 9 is changed from 4 mm 2 Adjusted to 8mm 2 , except for the above, other conditions are the same as those of Complete Example 1.

[0118] Embodiment 11

[0119] This embodiment provides a PVDF sound-generating film assembly, wherein the area occupied by each hollow hole of the first grid support layer 5 and the second grid support layer 9 is changed from 4 mm 2 Adjusted to 9mm 2 , except for the above, other conditions are the same as those of Complete Example 1.

[0120] Comparative Example 1

[0121] This comparative example provides a PVDF sound-emitting film assembly, in which the first grid support layer 5 and the second grid support layer 9 are not provided. Except for the above, other conditions are exactly the same as those in Example 1.

[0122] Characterization and Testing:

[0123] One side of the PVDF sound-generating film assembly obtained in the embodiment and the comparative example is adhered to the substrate, and the two wires at the output end of the audio amplifier device are respectively connected to the first electrode layer 2 and the second electrode layer 6 through the double-sided conductive copper tape provided on the pin part, and the same audio is played to check the sound effect.

[0124] The comparative example is attached to the substrate. Since there is no space for the film to vibrate, the film makes almost no sound after the audio amplifier device plays audio. The embodiment provides a mesh support layer so that the mesh support layer can provide appropriate support and mechanical buffering. When the component is attached and used, it can ensure that there is still a certain space on both sides of the PVDF layer, ensuring that the gas in these spaces can vibrate with the PVDF layer, thereby not affecting the sound.

[0125] From the above, it can be seen that the present invention provides a grid support layer so that the grid support layer can provide appropriate support and mechanical buffering. When the component is attached and used, it can ensure that a certain space is still retained on both sides of the PVDF layer, ensuring that the gas in these spaces can vibrate with the PVDF layer, thereby not affecting the sound.

[0126] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0127] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0128] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A PVDF sound-generating film assembly, characterized in that: The invention comprises an electrode layer, a protective layer and a grid support layer which are sequentially arranged on both sides of a PVDF layer.

2. The PVDF sound-generating film assembly according to claim 1, characterized in that: The thickness of the grid support layer is 10 to 500 μm; Preferably, the material of the grid support layer includes at least one of epoxy resin glue, UV glue or PLA material; Preferably, the hollow holes of the grid support layer are arranged in an array; Preferably, the shapes of the hollow holes of the grid support layer include polygonal and / or circular; Preferably, the area occupied by the hollow holes of each grid support layer is 0.01 to 8 mm. 2 .

3. The PVDF sound-generating film assembly according to claim 1 or 2, characterized in that: The thickness of the PVDF layer is 5 to 500 μm.

4. The PVDF sound-generating film assembly according to any one of claims 1 to 3, characterized in that: The electrode layer includes at least one of PEDOT:PSS, nanosilver wire, indium tin oxide or conductive silver paste; Preferably, the thickness of the electrode layer is 0.6-1 μm.

5. The PVDF sound-generating film assembly according to any one of claims 1 to 4, characterized in that: The PVDF sound-generating film assembly further includes a silver paste layer, and the silver paste layer is arranged between the electrode layer and the protective layer; Preferably, the thickness of the silver paste layer is 5 to 15 μm; Preferably, the silver paste layer is arranged on one side of the electrode layer close to the protective layer, along the four sides of the surface, to form a frame-shaped silver paste layer; Preferably, the electrode layer is provided with a pin portion, and the silver paste layer covers the pin portion; Preferably, a double-sided conductive copper tape is provided on the silver paste layer at the pin position.

6. The PVDF sound-generating film assembly according to any one of claims 1 to 5, characterized in that: The protective layer comprises a PET film; Preferably, the thickness of the protective layer is 30-80 μm.

7. A method for preparing the PVDF sound-generating film assembly according to any one of claims 1 to 6, characterized in that: The preparation method comprises: (1) providing a first protective layer, and forming a first electrode layer on one side of the first protective layer to obtain a first composite; providing a second protective layer, and forming a second electrode layer on one side of the second protective layer to obtain a second composite; (2) forming a PVDF initial film on the first electrode layer of the first composite body, and performing a first baking on the PVDF initial film to make the PVDF initial film sticky, thereby obtaining a third composite body; (3) pressing and laminating the second electrode layer in the second composite onto the PVDF initial film of the third composite, and performing a second baking to solidify the PVDF initial film into a PVDF layer, thereby obtaining a fourth composite; (4) A first mesh support layer and a second mesh support layer are formed on the first protective layer and the second protective layer in the fourth composite body, respectively.

8. The method for preparing the PVDF sound-generating film assembly according to claim 7, characterized in that: Step (1) comprises providing a first protective layer, and sequentially stacking a first silver paste layer and a first electrode layer on one side of the first protective layer to obtain a first composite body; providing a second protective layer, and sequentially stacking a second silver paste layer and a second electrode layer on one side of the second protective layer to obtain a second composite body; Preferably, in step (1), the method for forming the first silver paste layer and the second silver paste layer comprises firstly performing screen printing of 200-300 mesh, and then performing a third baking at 100-140° C. for 20-40 min; Preferably, in step (1), the method for forming the electrode layer comprises first performing at least one of 280-320 mesh screen printing, inkjet printing, mask coating or magnetron sputtering, and then performing a fourth baking at 100-140° C. for 10-20 min; Preferably, in step (4), the method of forming the grid support layer includes at least one of glue dispensing, 80-120 mesh screen printing or 3D printing.

9. The method for preparing the PVDF sound-generating film assembly according to claim 7 or 8, characterized in that: In step (2), the method for forming the PVDF initial membrane comprises: mixing a PVDF raw material with a solvent to prepare a PVDF precursor solution, and coating and / or casting the PVDF precursor solution to obtain a PVDF initial membrane; Preferably, the solvent comprises N,N-dimethylformamide; Preferably, the PVDF precursor solution is filtered using a 300-500 mesh gauze before use; Preferably, in the PVDF precursor solution, the mass ratio of the PVDF raw material to the solvent is 1:(5-20); Preferably, the preparation temperature of the PVDF precursor solution is 60-80°C; Preferably, the first baking temperature is 70-90° C. and the time is 1-3 hours; Preferably, the second baking is performed at a temperature of 100 to 120° C. for a time of 1 to 2 hours.

10. A loudspeaker, characterized in that: A PVDF sound-emitting film assembly comprising any one of claims 1 to 6.

Images