Plane horn of flexible circuit board and assembling method thereof

Abstract

The invention discloses a planar loudspeaker of a flexible circuit board and an assembling method thereof, and belongs to the technical field of loudspeakers, the planar loudspeaker comprises a shell, a washer is arranged at the bottom of the shell, an outer magnet and an inner magnet are arranged above the washer, a flexible board is arranged above the outer magnet and the inner magnet, an upper coil is arranged on the upper surface of the flexible board, and a lower coil is arranged on the lower surface of the flexible board. The upper coil, the flexible plate and the lower coil are pasted on the membrane, and the membrane is located at the upper end of the inner side of the shell. The problems that an existing diaphragm is not provided with a folding ring, the elasticity of the diaphragm becomes poor, the vibration amplitude becomes small, and the low-frequency performance of a loudspeaker becomes poor are solved. The flexible circuit board is adopted to replace a coil, the diaphragm is of a plane or an arc-shaped structure with a folding ring, only the attaching position of the diaphragm and the flexible circuit board is the plane, two bonding pads are directly led out of the flexible circuit board, the step of welding electronic wires of the horn is omitted, assembly is simpler, cost is lower, the consistency of the flexible circuit board is better, and the thickness is better; and the overall thickness and mass of the loudspeaker can be reduced.

Description

Technical Field

[0001] This invention relates to the field of loudspeaker technology, and in particular to a planar loudspeaker with a flexible circuit board and its assembly method. Background Technology

[0002] For loudspeakers, the voice coil, when energized with alternating current, is subjected to a magnetic field, causing the diaphragm to vibrate up and down. Therefore, the voice coil is a crucial component of the loudspeaker. Traditional loudspeaker voice coils are made by winding layers of wire together, bonding them to the diaphragm, and then soldering two voice coil wires to the circuit board. On one hand, the winding method, wire tightness, and temperature all affect the number of turns and diameter of the voice coil, and these variations significantly impact loudspeaker performance, resulting in poor consistency. On the other hand, after the voice coil is bonded to the diaphragm, the two voice coil wires must be aligned to prevent them from touching the diaphragm before soldering them to the circuit board. This alignment and soldering process is complex and carries the risk of wire breakage, leading to high costs and poor consistency.

[0003] Currently available speaker coil screen printing methods involve directly etching or screen printing the coil onto a diaphragm. However, this method only works with flat diaphragms, as curved diaphragms cannot be printed. For speakers, the diaphragm directly affects low-frequency performance. If the diaphragm lacks surrounds, its elasticity decreases, its vibration amplitude reduces, and the speaker's low-frequency performance deteriorates. Summary of the Invention

[0004] The purpose of this invention is to provide a planar speaker with a flexible circuit board and its assembly method, which is simpler to assemble, lower in cost, and has better consistency and thickness of flexible circuit board, making it easier to reduce the overall thickness and weight of the speaker and improve the low-frequency performance of the speaker, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A planar speaker with a flexible circuit board includes a housing, a washer at the bottom of the housing, an outer magnet and an inner magnet above the washer, wherein the inner magnet is located inside the outer magnet, a flexible plate above the outer magnet and the inner magnet, an upper coil on the upper surface of the flexible plate, a lower coil on the lower surface of the flexible plate, the upper coil, the flexible plate and the lower coil are attached to a diaphragm, and the diaphragm is located at the upper end of the inner side of the housing.

[0007] Specifically, a flexible circuit board is used to replace the coil. The outer dimensions of the flexible circuit board are similar to the outer diameter of the voice coil, so it can be directly attached to the diaphragm. The shape of the diaphragm can be flat or have an arc-shaped structure with folds, as long as the attachment point with the flexible circuit board is flat. The flexible circuit board can directly lead out two solder pads, eliminating the step of soldering electronic wires to the speaker. Therefore, the assembly is simpler and the cost is lower. In addition, the flexible circuit board has better consistency and thickness, which makes it easier to reduce the overall thickness and weight of the speaker.

[0008] Preferably, the washer has a central hole.

[0009] Preferably, the external magnet and the internal magnet form a magnetic circuit system. The magnetic circuit system consists of an external magnet and an internal magnet below the diaphragm, or an external magnet and an internal magnet on both the upper and lower surfaces of the diaphragm. The external magnet and the internal magnet are either circular or square, and the material of the external magnet and the internal magnet is neodymium iron boron permanent magnet.

[0010] Preferably, the external magnet and the internal magnet have opposite magnetic properties, and both the external magnet and the internal magnet are magnetic in the Y-axis direction.

[0011] Specifically, the washer directs the magnetic field from the bottom of the outer and inner magnets to the top of the outer and inner magnets, increasing the efficiency of the voice coil in the magnetic field. The washer is embedded in the outer shell and does not occupy any height space.

[0012] Preferably, the washer is made of SPCC or SPCE magnetic material with a thickness of 0.1-0.4mm, and the washer is used to guide the magnetic field at the bottom of the outer and inner magnets to the top of the outer and inner magnets.

[0013] Preferably, the upper and lower coils are made of copper wire, copper-clad aluminum, or aluminum wire, the flexible board substrate is one or more composite materials selected from PI, PET, PEN, and Peek, the upper and lower coils are thin spiral conductive layers, the upper and lower coils are hollow structures, and the shape is circular, square, or elliptical. The thickness of the upper and lower coils is 1µm-50µm.

[0014] Preferably, the diaphragm is circular or square, with a flat surface in the middle for attaching to the flexible plate, and the folds of the diaphragm are arc-shaped or flat.

[0015] Preferably, the upper coil and the lower coil on the flexible plate are connected through through holes and the connection directions are opposite, that is, the outlet of the upper coil is connected to the inlet of the lower coil, and the ends of the upper coil and the lower coil have solder pads, which are used to connect the circuit of the whole machine.

[0016] According to another aspect of the present invention, a method for assembling a planar speaker on a flexible circuit board is provided, for assembling a planar speaker on a flexible circuit board as described above, comprising the following steps:

[0017] S1: Place an outer magnet and an inner magnet on the upper surface of the washer, and place the inner magnet inside the outer magnet;

[0018] S2: An upper coil is placed on the upper surface of the flexible board, and a lower coil is placed on the lower surface of the flexible board to form a flexible circuit board;

[0019] S3: Attach the flexible circuit board to the diaphragm and install the diaphragm on the upper part of the inner side of the housing 1. Assemble the housing onto the washer so that the washer is embedded in the inner side of the bottom of the housing, thus completing the assembly of the planar speaker.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] This invention uses a flexible circuit board to replace the voice coil. The flexible circuit board is constructed by etching circuitry onto a very thin PI substrate. The circuitry can be on one or both sides, and multiple layers of the coil can be used. The outer dimensions of the flexible circuit board are similar to the outer diameter of the voice coil, allowing it to be directly bonded to the diaphragm. The diaphragm can be flat or have an arc-shaped structure with folds, as long as the bonding position with the flexible circuit board is flat. The flexible circuit board can directly lead out two solder pads, eliminating the step of soldering electronic wires to the speaker. Therefore, assembly is simpler and the cost is lower. Furthermore, the flexible circuit board has better consistency and thickness, which helps to reduce the overall thickness and weight of the speaker. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the planar loudspeaker according to Embodiment 1 of the present invention;

[0023] Figure 2 This is an exploded view of a planar loudspeaker according to Embodiment 1 of the present invention;

[0024] Figure 3 This is a cross-sectional schematic diagram of a planar loudspeaker according to Embodiment 1 of the present invention;

[0025] Figure 4 This is a cross-sectional schematic diagram of a planar horn according to Embodiment 2 of the present invention;

[0026] Figure 5 This is a cross-sectional schematic diagram of the planar horn according to Embodiment 3 of the present invention;

[0027] Figure 6 This is a cross-sectional schematic diagram of the planar horn according to Embodiment 4 of the present invention;

[0028] Figure 7 This is a schematic diagram of the flexible circuit board according to Embodiment 1 of the present invention;

[0029] Figure 8 This is a schematic diagram of the flexible circuit board according to Embodiment 5 of the present invention;

[0030] Figure 9 For the present invention Figure 7 Enlarged view of point A in the image.

[0031] In the diagram: 1. Outer shell; 2. Diaphragm; 3. Upper coil; 4. Flexible board; 41. Through hole; 5. Lower coil; 6. External magnet; 7. Internal magnet; 8. Washer; 9. Middle hole; 10. Front cover; 11. Solder pad. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] To address the problem that existing diaphragms lack pleats, resulting in decreased elasticity, reduced vibration amplitude, and consequently, poorer low-frequency performance of the speaker, this embodiment provides the following technical solution:

[0034] Example 1

[0035] Please see Figures 1-3 A planar speaker with a flexible circuit board includes a housing 1, a washer 8 at the bottom of the housing 1, an outer magnet 6 and an inner magnet 7 above the washer 8, wherein the inner magnet 7 is located inside the outer magnet 6.

[0036] In this embodiment, the outer magnet 6 and the inner magnet 7 form a magnetic circuit system. The magnetic circuit system consists of the outer magnet 6 and the inner magnet 7 below the diaphragm 2, or the outer magnet 6 and the inner magnet 7 are located above and below the diaphragm 2. The outer magnet 6 and the inner magnet 7 are either circular or square, and the material of the outer magnet 6 and the inner magnet 7 is neodymium iron boron permanent magnet.

[0037] In this embodiment, the outer magnet 6 and the inner magnet 7 have opposite magnetic properties, and both the outer magnet 6 and the inner magnet 7 are magnetic in the Y-axis direction. There may or may not be a gap between the outer magnet 6 and the inner magnet 7.

[0038] Please see Figure 7 and Figure 9 A flexible plate 4 is provided above the outer magnet 6 and the inner magnet 7. An upper coil 3 is provided on the upper surface of the flexible plate 4, and a lower coil 5 is provided on the lower surface of the flexible plate 4. The upper coil 3, the flexible plate 4 and the lower coil 5 are attached to the diaphragm 2. The diaphragm 2 is located at the upper end of the inner side of the outer shell 1. The upper coil 3 and the lower coil 5 are led out from the bottom.

[0039] In this embodiment, the washer 8 is made of SPCC or SPCE magnetic conductive material with a thickness of 0.1-0.4mm. The washer 8 is used to guide the magnetic field at the bottom of the outer magnet 6 and the inner magnet 7 to the top of the outer magnet 6 and the inner magnet 7, thereby increasing the efficiency of the voice coil in the magnetic field. The washer 8 is embedded in the outer shell 1 and does not occupy any height space.

[0040] In this embodiment, the upper coil 3 and the lower coil 5 are made of copper wire, copper-clad aluminum or aluminum wire, and the substrate of the flexible plate 4 is one or more composite materials selected from PI, PET, PEN and Peek.

[0041] The diaphragm 2 is circular or square, with a flat surface in the middle for attaching to the flexible plate 4. The folds of the diaphragm 2 are arc-shaped or flat.

[0042] In this embodiment, the upper coil 3 and the lower coil 5 are thin spiral conductive layers. The upper coil 3 and the lower coil 5 have hollow structures and are circular, square or elliptical in shape. The thickness of the upper coil 3 and the lower coil 5 is 1um-50um.

[0043] It should be noted that the upper coil 3 and the lower coil 5 are thin spiral conductive layers, such as copper, aluminum, silver, etc., with a thickness of 1um-50um. The upper coil 3 and the lower coil 5 are hollow structures, and their shapes can be circular, square, or elliptical. The upper coil 3 and the lower coil 5 can be a single layer or multiple layers, and the upper coil 3 and the lower coil 5 are led out from the bottom.

[0044] It should be noted that the shape of the flexible board 4 is determined by the shape of the upper coil 3 and the lower coil 5. It can be round, square or oval, etc. The material can be an insulating film such as PI, PET or PEN with a thickness of 2um-30um. The center of the flexible board 4 can be cut out or it can be solid. When the flexible circuit board is finished, two solder pads 11 are brought out to connect the circuit of the whole machine.

[0045] The flexible circuit board has an arc-shaped lead-out section that will not break during vibration. The upper and lower multi-layer coils are connected through through holes 41, and the connection directions are opposite, that is, the outlet of the upper coil 3 is connected to the inlet of the lower coil 5.

[0046] In this embodiment, the upper coil 3 and the lower coil 5 provided on the flexible plate 4 are connected through the through hole 41, and the connection direction is opposite, that is, the outlet of the upper coil 3 is connected to the inlet of the lower coil 5, and the ends of the upper coil 3 and the lower coil 5 are led out to the solder pads 11, which are used to connect the whole circuit.

[0047] It should be noted that the voice coil is replaced by a flexible circuit board. Because it is very thin, it is lighter and the high-frequency performance of the speaker is better. The upper coil 3 and the lower coil 5 are made of materials with good conductivity such as copper wire, copper-clad aluminum, or aluminum wire. The substrate of the flexible board 4 is one or more composite materials such as PI, PET, PEN, and Peek. The extrusion shape can be round or square. The flexible board 4 can also have coils on both the top and bottom, presenting a dual-coil structure. This doubles the number of turns of the speaker coil and can improve the sensitivity by 3dB.

[0048] Specifically, after the upper coil 3 and lower coil 5 on the flexible circuit board are energized, they vibrate up and down under the influence of the magnetic field, thereby causing the diaphragm 2 to vibrate up and down as well.

[0049] To better illustrate the assembly process of a planar speaker made of a flexible circuit board, this embodiment provides a method for assembling a planar speaker made of a flexible circuit board as described above, comprising the following steps:

[0050] S1: Place an outer magnet 6 and an inner magnet 7 on the upper surface of the washer 8, and place the inner magnet 7 inside the outer magnet 6;

[0051] S2: An upper coil 3 is provided on the upper surface of the flexible board 4, and a lower coil 5 is provided on the lower surface of the flexible board 4 to form a flexible circuit board;

[0052] S3: Attach the flexible circuit board to the diaphragm 2 and install the diaphragm 2 on the upper part of the inner side of the housing 1. Assemble the housing 1 onto the washer 8 so that the washer 8 is embedded in the inner side of the bottom of the housing 1, thus completing the assembly of the planar speaker.

[0053] Example 2

[0054] Please see Figure 4 The difference from Example 1 is that the structure of Wasi 8 is different.

[0055] In this embodiment, the washer 8 is provided with a central hole 9.

[0056] To better illustrate the assembly process of a planar speaker made of a flexible circuit board, this embodiment provides a method for assembling a planar speaker made of a flexible circuit board as described above, comprising the following steps:

[0057] S1: Place an outer magnet 6 and an inner magnet 7 on the upper surface of the washer 8, and place the inner magnet 7 inside the outer magnet 6;

[0058] S2: An upper coil 3 is provided on the upper surface of the flexible board 4, and a lower coil 5 is provided on the lower surface of the flexible board 4 to form a flexible circuit board;

[0059] S3: Attach the flexible circuit board to the diaphragm 2 and install the diaphragm 2 on the upper part of the inner side of the housing 1. Assemble the housing 1 onto the washer 8 so that the washer 8 is embedded in the inner side of the bottom of the housing 1, thus completing the assembly of the planar speaker.

[0060] Example 3

[0061] Please see Figure 5 The difference from Embodiment 1 lies in the different structures of the washer 8 and the outer shell 1.

[0062] In this embodiment, the top of the outer shell 1 is provided with a front cover 10, and the outer shell 1 is provided with an outer magnet 6 and an inner magnet 7. The inner magnet 7 is located inside the outer magnet 6. A flexible plate 4 is provided above the outer magnet 6 and the inner magnet 7. An upper coil 3 is provided on the upper surface of the flexible plate 4, and a lower coil 5 is provided on the lower surface of the flexible plate 4. The upper coil 3, the flexible plate 4 and the lower coil 5 are attached to the diaphragm 2. The diaphragm 2 is located at the upper end of the inner side of the outer shell 1.

[0063] To better illustrate the assembly process of a planar speaker made of a flexible circuit board, this embodiment provides a method for assembling a planar speaker made of a flexible circuit board as described above, comprising the following steps:

[0064] S1: Place an outer magnet 6 and an inner magnet 7 inside the outer casing 1, and place the inner magnet 7 inside the outer magnet 6;

[0065] S2: An upper coil 3 is provided on the upper surface of the flexible board 4, and a lower coil 5 is provided on the lower surface of the flexible board 4 to form a flexible circuit board;

[0066] S3: Attach the flexible circuit board to the diaphragm 2, install the diaphragm 2 on the upper part of the inner side of the housing 1, and install the front cover 10 on the top of the housing 1 to complete the assembly of the planar speaker.

[0067] Example 4

[0068] Please see Figure 6 The difference from Embodiment 3 is that the structure of the outer shell 1 is different.

[0069] In this embodiment, the outer shell 1 is provided with a central hole 9.

[0070] To better illustrate the assembly process of a planar speaker made of a flexible circuit board, this embodiment provides a method for assembling a planar speaker made of a flexible circuit board as described above, comprising the following steps:

[0071] S1: Place an outer magnet 6 and an inner magnet 7 inside the outer casing 1, and place the inner magnet 7 inside the outer magnet 6;

[0072] S2: An upper coil 3 is provided on the upper surface of the flexible board 4, and a lower coil 5 is provided on the lower surface of the flexible board 4 to form a flexible circuit board;

[0073] S3: Attach the flexible circuit board to the diaphragm 2, install the diaphragm 2 on the upper part of the inner side of the housing 1, and install the front cover 10 on the top of the housing 1 to complete the assembly of the planar speaker.

[0074] Example 5

[0075] Please see Figure 8 The difference from Embodiment 1 is that the upper coil 3 and the lower coil 5 have different structures.

[0076] In this embodiment, the upper coil 3 and the lower coil 5 are led out from the side.

[0077] It should be noted that the upper coil 3 and the lower coil 5 are thin spiral conductive layers, such as copper, aluminum, silver, etc., with a thickness of 1um-50um. The upper coil 3 and the lower coil 5 are hollow structures, and their shapes can be circular, square, or elliptical. The upper coil 3 and the lower coil 5 can be a single layer or multiple layers, and the upper coil 3 and the lower coil 5 are led out from the side.

[0078] It should be noted that the shape of the flexible board 4 is determined by the shape of the upper coil 3 and the lower coil 5. It can be round, square or oval, etc. The material can be an insulating film such as PI, PET or PEN with a thickness of 2um-30um. The center of the flexible board 4 can be cut out or it can be solid. When the flexible circuit board is finished, two solder pads 11 are brought out to connect the circuit of the whole machine.

[0079] The flexible circuit board extends from the side and will not break even when the vibration amplitude is greater. The upper and lower multi-layer coils are connected through through holes 41, and the connection directions are opposite, that is, the outlet of the upper coil 3 is connected to the inlet of the lower coil 5.

[0080] Working principle: A flexible circuit board is used to replace the voice coil. The structure of the flexible circuit board is: the circuit is etched on a very thin PI substrate, which can be one side or two sides of the circuit, with multiple layers of coil. The outer dimensions of the flexible circuit board are similar to the outer diameter of the voice coil, so it can be directly attached to the diaphragm. The shape of the diaphragm can be flat or have an arc structure with folds, as long as the attachment point with the flexible circuit board is flat. The flexible circuit board can directly lead out two pads, eliminating the step of soldering electronic wires to the speaker. Therefore, the assembly is simpler and the cost is lower. In addition, the flexible circuit board has better consistency and thickness, which makes it easier to reduce the overall thickness and weight of the speaker.

[0081] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A planar speaker made of a flexible circuit board, comprising a housing (1), characterized in that, The bottom of the outer shell (1) is provided with a washer (8), and an outer magnet (6) and an inner magnet (7) are provided above the washer (8). The inner magnet (7) is located inside the outer magnet (6). A flexible plate (4) is provided above the outer magnet (6) and the inner magnet (7). An upper coil (3) is provided on the upper surface of the flexible plate (4), and a lower coil (5) is provided on the lower surface of the flexible plate (4). The upper coil (3), the flexible plate (4) and the lower coil (5) are attached to a diaphragm (2). The diaphragm (2) is located at the upper end of the inner side of the outer shell (1).

2. The planar speaker of a flexible circuit board according to claim 1, characterized in that, The washer (8) is provided with a central hole (9).

3. A planar speaker on a flexible circuit board according to claim 2, characterized in that, The external magnet (6) and the internal magnet (7) form a magnetic circuit system. The magnetic circuit system consists of an external magnet (6) and an internal magnet (7) below the diaphragm (2), or an external magnet (6) and an internal magnet (7) above and below the diaphragm (2).

4. A planar speaker on a flexible circuit board according to claim 3, characterized in that, The outer magnet (6) and the inner magnet (7) are either circular or square, and the outer magnet (6) and the inner magnet (7) are made of neodymium iron boron permanent magnets.

5. A planar speaker on a flexible circuit board according to claim 4, characterized in that, The outer magnet (6) and the inner magnet (7) have opposite magnetic properties, and both the outer magnet (6) and the inner magnet (7) are magnetic in the Y-axis direction.

6. A planar speaker on a flexible circuit board according to claim 5, characterized in that, The washer (8) is made of SPCC or SPCE magnetic material with a thickness of 0.1-0.4mm. The washer (8) is used to guide the magnetic field at the bottom of the outer magnet (6) and the inner magnet (7) to the top of the outer magnet (6) and the inner magnet (7).

7. A planar speaker on a flexible circuit board according to claim 6, characterized in that, The upper coil (3) and lower coil (5) are made of copper wire, copper-clad aluminum or aluminum wire, and the substrate of the flexible plate (4) is one or more composite materials of PI, PET, PEN or Peek.

8. A planar speaker on a flexible circuit board according to claim 7, characterized in that, The diaphragm (2) is circular or square, and the diaphragm (2) has a flat surface in the middle for attaching to the flexible plate (4). The folds of the diaphragm (2) are arc-shaped or flat.

9. A planar speaker on a flexible circuit board according to claim 8, characterized in that, The upper coil (3) and the lower coil (5) are thin spiral conductive layers. The upper coil (3) and the lower coil (5) are hollow structures with a circular, square or elliptical shape. The thickness of the upper coil (3) and the lower coil (5) is 1um-50um. The upper coil (3) and the lower coil (5) provided on the flexible plate (4) are connected through through holes (41) and the connection directions are opposite, that is, the outlet of the upper coil (3) is connected to the inlet of the lower coil (5). The ends of the upper coil (3) and the lower coil (5) have solder pads (11) for connecting the whole machine circuit.

10. A method for assembling a planar speaker on a flexible circuit board, used for assembling a planar speaker on a flexible circuit board as described in claim 9, characterized in that, Includes the following steps: S1: Place an outer magnet (6) and an inner magnet (7) on the upper surface of the washer (8), and place the inner magnet (7) inside the outer magnet (6); S2: An upper coil (3) is provided on the upper surface of the flexible board (4), and a lower coil (5) is provided on the lower surface of the flexible board (4) to form a flexible circuit board; S3: Attach the flexible circuit board to the diaphragm (2) and install the diaphragm (2) on the upper part of the inner side of the outer shell (1). Assemble the outer shell (1) on the washer (8) so that the washer (8) is embedded in the inner side of the bottom of the outer shell (1) to complete the assembly of the planar speaker.

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