A FPCB rolled voice coil and a manufacturing method thereof

Abstract

The present invention discloses an FPCB rolled voice coil and a manufacturing method thereof, wherein the FPCB rolled voice coil comprises: an insulating base layer, which is made of a flexible material and has stretching elasticity; a conductive layer, which is arranged on the insulating base layer and comprises at least one group of conductors distributed along an S-shaped path, and all the conductors are electrically connected; wiring pins, which are arranged at the edge of the insulating base layer, and are electrically connected to at least one group of conductors. A skeleton, which is arranged in a columnar structure; the insulating base layer is wound on the skeleton, and the number of layers of the insulating base layer on the same side of the skeleton after winding is at least two. The technical solution provided by the present invention, by presetting an FPC with a circuit pattern, forms a coil winding of a preset width and thickness according to structural requirements, and has obvious advantages in terms of manufacturing efficiency and adaptation of voice coils of different size requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of transducers, and relates to a wireless microphone, a wired microphone and a loudspeaker, in particular to an FPCB rolled voice coil and a manufacturing method thereof. Background Art

[0002] The working principle of the voice coil is based on the Lorentz force, that is, when a charged conductor is in a magnetic field, it will be acted upon by a force. In a loudspeaker, the voice coil is located in a magnetic field. When the audio current passes through the voice coil, the voice coil will be subjected to a force perpendicular to the direction of the current and the direction of the magnetic field. This force will cause the voice coil to vibrate mechanically. Specifically, when a current I is passed through the voice coil in the magnetic gap of the loudspeaker with a magnetic field strength of B, the voice coil will be subjected to an electromotive force F=BLI (L is the length of the voice coil), and the direction of the force follows the left-hand rule. After the force occurs, when the electromagnetic system including the voice coil cuts the magnetic flux lines at a speed of V, an induced voltage BLV will be generated inside the voice coil, and its direction conforms to the right-hand rule and is opposite to the original current direction. At this time, the voice coil is the initiator of damping and the recipient of damping.

[0003] The voice coil usually consists of a coil wound on a skeleton, which can be made of paper, plastic or other insulating materials. The coil is usually wound with enameled wire, and the outer layer of the enameled wire is coated with insulating varnish to prevent the wires inside the coil from touching each other. The two ends of the voice coil are usually connected to the circuit of the speaker. When current passes through the voice coil, the voice coil will be affected by the force in the magnetic field, resulting in mechanical vibration.

[0004] The production process of a voice coil usually includes the following steps:

[0005] Winding: The enameled wire is wound around the frame to form the coil of the voice coil. The number of turns and wire diameter of the winding are usually determined according to the design requirements of the speaker.

[0006] Insulation: After winding, the voice coil usually needs to be insulated to prevent the wires inside the coil from touching each other.

[0007] Connect the leads: Both ends of the voice coil need to be connected to the speaker's circuit, usually by soldering or other connecting methods to connect the leads to the voice coil.

[0008] Testing and adjustment: The finished voice coil needs to be tested for electrical and mechanical properties to ensure that it meets the design requirements.

[0009] From the above-mentioned traditional voice coil manufacturing process, it can be seen that the enameled copper wire needs to be made first, and then the enameled copper wire is wound on the frame; during the winding process, the enameled wire is prone to position deviation, resulting in a decrease in the uniformity of the entire coil, affecting the performance of the voice coil. Most of the enameled wires in the prior art are single-layer designs, and the performance of single-layer enameled wire voice coils is gradually unable to meet market demand.

[0010] If multiple layers of enameled wire are stacked by single-layer winding, the outer enameled wire will exert force on the inner enameled wire, which will cause the position of the inner enameled wire to shift, reduce the neatness of the overall enameled wire winding, and reduce the performance of the voice coil.

[0011] In the prior art, there are also racetrack-shaped horizontally stacked voice coils. Single-layer horizontal voice coils are mainly used for thin audio devices, such as mobile phone speakers, wireless headphones, etc., and are generally made by thin-film PCB electroplating patterns. However, single-layer horizontal voice coils also have performance defects and cannot meet market demand. At present, multi-layer horizontal stacked winding designs cannot be realized on the market. Summary of the invention

[0012] In order to overcome the shortcomings of the prior art, an FPCB rolled voice coil and a manufacturing method thereof are proposed.

[0013] A FPCB rolled voice coil, comprising:

[0014] An insulating base layer, wherein the insulating base layer is made of a flexible material and has elongation elasticity;

[0015] A conductive layer, the conductive layer is disposed on the insulating base layer and includes at least one group of conductors, all of which are electrically connected;

[0016] A wiring pin is arranged at an edge of the insulating base layer, and the wiring pin is electrically connected to at least one group of the conductors.

[0017] A frame, wherein the frame is arranged in a columnar structure;

[0018] The insulating base layer is wound on the frame, and the number of layers of the insulating base layer on the same side of the frame after winding is at least two.

[0019] The present invention also provides a method for manufacturing a rolled FPCB voice coil:

[0020] A method for manufacturing an FPCB rolled voice coil, the method is used to manufacture the FPCB rolled voice coil as described above, and comprises:

[0021] S100, assuming that the number of insulating base layers having a preset thickness value is at least two groups, preparing a conductive layer for each group of the insulating base layers to obtain an insulating base layer having the conductive layer;

[0022] S200, stacking the groups of insulating base layers with conductive layers parallel to each other, and aligning one end of the insulating base layers of each group to be stacked and fixed as a whole, and arranging the other end along a straight line direction;

[0023] S300, starting from one end of each group of insulating base layers aligned and overlapped, each group of insulating base layers is concentrically wound around the outer wall of the preset frame with the axial direction of the preset frame as the center;

[0024] S400, electrically connecting the connection pin to a preset audio signal transfer circuit;

[0025] Among them, the edge of the insulating base layer with the conductive layer has wiring pins electrically connected to the conductive layer; when concentrically wound and wrapped, the length values ​​of each group of the insulating base layers are in an arithmetic progression, and the length values ​​are determined by the radius of the preset skeleton and the thickness value.

[0026] The present invention also proposes another method for manufacturing a rolled FPCB voice coil:

[0027] A method for manufacturing an FPCB rolled voice coil, the method is used to manufacture the FPCB rolled voice coil as described above, and comprises:

[0028] S100, assuming that the number of insulating base layers is one group, preparing a conductive layer on the insulating base layers to obtain an insulating base layer with the conductive layer;

[0029] S200, gluing or electrostatically treating the insulating base layer with the conductive layer;

[0030] S300, winding and coating the insulating base layer after glue coating on the outer wall of the preset skeleton with at least two layers around the axial direction of the preset skeleton, and the cross section of the insulating base layer after the overall winding and coating is spiral;

[0031] S400, electrically connecting the connection pin to a preset audio signal transfer circuit;

[0032] Wherein, the edge of the insulating base layer with the conductive layer has a connection pin electrically connected to the conductive layer.

[0033] The FPCB rolled voice coil and the manufacturing method thereof provided by the present invention have the following beneficial effects:

[0034] 1. Using an insulating base layer based on flexible materials as the carrier of the voice coil winding can realize the free distribution of the winding in the horizontal and vertical directions, and the winding is convenient; at the same time, the position of the winding fixedly embedded in the flexible substrate is restricted by the flexible substrate, and the degree of deviation is greatly reduced, effectively ensuring the acoustic performance of the voice coil.

[0035] 2. According to the parameter requirements of the winding size corresponding to the voice coil performance, the production personnel can control the size of the winding by controlling the size of the flexible substrate (i.e. the length and thickness of the insulating base layer) before winding, thereby ensuring that the physical properties of each layer of winding are consistent, achieving overall performance consistency of the voice coil and improving the acoustic effect.

[0036] 3. Compared with the traditional voice coil forming method of winding copper wire turn by turn, the integral FPCB winding structure provided by this solution has a greatly reduced number of windings. On the one hand, it effectively improves the efficiency of voice coil manufacturing and forming. On the other hand, the winding is loaded on the FPCB substrate, and the influence of external interference or self-stress factors during the winding process is greatly reduced, which effectively improves the smoothness of voice coil winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of an insulating base layer with a conductive layer in an embodiment of the present invention;

[0038] Figure 2 Schematic diagram of a FPCB rolled voice coil in an embodiment of the present invention;

[0039] Figure 3 Schematic diagram of concentric winding in the method for manufacturing a rolled FPCB voice coil in an embodiment of the present invention;

[0040] Figure 4 It is a schematic diagram of multiple groups of insulating base layers of equal length in the method for manufacturing a rolled FPCB voice coil in an embodiment of the present invention;

[0041] Figure 5 Another schematic diagram of multiple groups of insulating base layers of equal lengths in the method for manufacturing a rolled FPCB voice coil in an embodiment of the present invention;

[0042] Figure 6 It is a schematic diagram of the overall winding and covering of a single set of insulating base layers in the method for manufacturing a rolled FPCB voice coil in an embodiment of the present invention;

[0043] The symbols in the drawings of the specification are as follows:

[0044] 1. Insulation base layer; 2. Conductive layer; 3. Wiring pins; 4. Frame. DETAILED DESCRIPTION

[0045] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0046] Embodiment 1 provides a FPCB rolled voice coil, comprising:

[0047] Insulation base layer 1, the insulation base layer is made of flexible material, so that the insulation base layer has a certain extension elasticity and can be annularly wound. The typical insulation base layer adopts FPCB;

[0048] Conductive layer 2, the conductive layer is arranged on the insulating base layer, and includes at least one group of conductors 3, all of which are electrically connected. Specifically, the conductive layer can be formed inside the insulating base layer or on the end surface of the insulating base layer. Specifically, the conductive layer is formed on the insulating base layer by laser engraving, electroplating, etching molding, etc.; the conductors are distributed along an S-shaped path or in parallel. The conductive layer can have a double-layer structure and a staggered design, which can prevent short circuits and increase the magnetic flux of the conductive layer.

[0049] Wiring pins 3, which are arranged at the edge of the insulating base layer and are electrically connected to at least one group of conductors. The wiring pins are used to be electrically connected to the audio signal transfer circuit;

[0050] The skeleton 4 is a columnar structure, such as a cylinder, but not limited thereto;

[0051] Among them, the single-layer insulation base structure before winding is as follows Figure 1 As shown, the conductive layer is arranged along a straight line structure and is bent in an S shape, and the extension path of the conductive layer is located in the plane where the insulating base winding path is located. Figure 2 As shown, the number of insulating base layers on the same side of the frame is at least two, and the outer diameter of the insulating base layer gradually increases from the center axis of the frame toward the outside, that is, the performance defects of the single-layer voice coil in the prior art are overcome.

[0052] Furthermore, in one implementation, the insulating base layer includes a superimposed portion and a winding portion, the superimposed portion is used for stacking, bonding and fixing, the winding portion is made of a soft material, the winding portion is arranged at one end of the superimposed portion, the conductive layer is formed on the winding portion, the winding portion is an FPCB, and the superimposed portion is a hard metal or a soft material; when the superimposed portion is made of hard metal, it is superimposed and fixed by hot pressing and serves as a wiring pin.

[0053] Embodiment 2 provides a method for manufacturing a rolled voice coil of FPCB, such as Figures 3 to 5 As shown, the main idea for making the above-mentioned FPCB rolled voice coil is as follows: the initial state of the insulating base layer is set in a rectangular flat plate structure, all the insulating base layers are stacked in sequence before winding, and after stacking to a preset number of layers, all the insulating base layers are set in a cubic plate structure as a whole, and then the entire insulating base layer is wound on the frame by a winding device, thereby completing the voice coil production. Specifically including the steps:

[0054] S100, assuming that the number of insulating base layers with a preset thickness value is at least two groups, and preparing a conductive layer for each group of insulating base layers to obtain an insulating base layer with a conductive layer; wherein, when preparing the conductive layer, it can be formed on the insulating base layer by any one of laser engraving, electroplating, and etching. The edge of the insulating base layer with the conductive layer has a wiring pin electrically connected to the conductive layer, which is convenient for connecting to the audio signal switching circuit.

[0055] S200, stacking each group of insulating base layers with a conductive layer parallel to each other, and aligning one end of each group of insulating base layers to be stacked and fixed as a whole, and the other end is arranged in a straight direction; wherein, specifically, one end of each group of insulating base layers can be aligned, stacked and fixed as a whole by means of adhesive or ultrasonic welding.

[0056] S300, starting from one end where each group of insulating base layers are aligned and overlapped, each group of insulating base layers is concentrically wound around the outer wall of the preset skeleton with the axial direction of the preset skeleton as the center; wherein the axial direction of the skeleton is, for example, the height direction of the cylinder, taking the cylindrical skeleton as an example. The concentric winding and wrapping can be fixed by adhesive or ultrasonic welding. During the concentric winding and wrapping, the length values ​​of each group of insulating base layers are in an arithmetic progression, and the length values ​​are determined by the radius and thickness value of the preset skeleton.

[0057] S400, electrically connecting the connection pins to a preset audio signal transfer circuit.

[0058] Specifically, before winding, the length difference between two adjacent stacked insulating base layers is set to D1, D2, and D3. When the thickness of all insulating base layers is the same, D1 = D2 = D3. After winding, each set of insulating base layers forms a ring structure with different radii (or inner diameters if the shape is not a standard circle), for example:

[0059] Assume that there are four groups of insulating base layers, namely the first base layer, the second base layer, the third base layer and the fourth base layer, and their lengths are L1, L2, L3 and L4 respectively. The four are stacked in sequence according to their lengths; then the difference between L1 and L2 is D1, the difference between L2 and L3 is D2, and the difference between L3 and L4 is D3.

[0060] After the first base layer, the second base layer, the third base layer and the fourth base layer are wound, they respectively form annular structures with outer diameters of R1, R2, R3 and R4. Taking the circular structure as an example, since the circumference D=2πR, therefore, D1=2π(R2-R1).

[0061] Therefore, the length of each group of base layers can be determined according to the skeleton radius R and the thickness of the base layer. In theory, after pattern etching, laser engraving or electroplating of an insulating base layer (FPCB) of any size, the FPC with the corresponding circuit coil pattern can be cut to a preset length according to the needs of the target voice coil and wound to obtain a coil winding, which can greatly improve the circuit pattern forming efficiency and the voice coil winding forming efficiency.

[0062] Embodiment 3 provides another method for manufacturing a rolled voice coil of FPCB, such as Figure 6 As shown, it is used to make the above-mentioned FPCB rolled voice coil, and includes the steps of:

[0063] S100, assuming that the number of insulating base layers is a group, a conductive layer is prepared on the insulating base layer to obtain an insulating base layer with a conductive layer; wherein the conductive layer can be formed on the insulating base layer by any one of laser engraving, electroplating, and etching. The edge of the insulating base layer with the conductive layer has a wiring pin electrically connected to the conductive layer, which is convenient for connecting to the audio signal switching circuit.

[0064] S200, the insulating base layer with the conductive layer is entirely coated with glue.

[0065] S300, the insulating base layer coated with glue is wound and coated on the outer wall of the preset skeleton in at least two layers with the axial direction of the preset skeleton as the center, and the cross-section of the insulating base layer after the winding and coating is spiral.

[0066] S400, electrically connecting the connection pins to a preset audio signal transfer circuit.

[0067] The method provided in this embodiment is to wind and coat a group of insulating base layers as a whole so that the cross section of the insulating base layers is arranged in a spiral structure, thereby obtaining a rolled voice coil of at least two layers. Compared with the manufacturing method of Example 2, the method in this embodiment is simpler and has lower cost. It can be understood that in actual production, an appropriate manufacturing method can be flexibly selected according to customer needs.

[0068] In summary, the present invention is equivalent to providing a "prefabricated" winding film, which is cut to a preset size and then wound on a frame to achieve winding formation. Compared with the prior art, by pre-setting an FPC with a circuit pattern, a coil winding with a preset width and thickness is formed according to structural requirements, which has obvious advantages in terms of production efficiency and adaptation of voice coils of different size requirements.

[0069] The above is an explanation of the FPCB rolled voice coil and the manufacturing method thereof of the present invention, which is used to help understand the present invention; however, the implementation mode of the present invention is not limited to the above-mentioned embodiments, and any changes, modifications, substitutions, combinations, and simplifications made without departing from the principles of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims

1. A FPCB rolled voice coil, characterized in that: include: An insulating base layer, wherein the insulating base layer is made of a flexible material and has elongation elasticity; A conductive layer, the conductive layer is disposed on the insulating base layer and includes at least one group of conductors, all of which are electrically connected; A wiring pin is arranged at an edge of the insulating base layer, and the wiring pin is electrically connected to at least one group of the conductors. A frame, wherein the frame is arranged in a columnar structure; The insulating base layer is wound on the frame, and the number of layers of the insulating base layer on the same side of the frame after winding is at least two.

2. The FPCB rolled voice coil according to claim 1, characterized in that: The insulating base layer includes an overlapping portion and a winding portion, the overlapping portion is used for stacking, bonding and fixing, the winding portion is made of a soft material, the winding portion is arranged at one end of the overlapping portion, the conductive layer is formed on the winding portion, the winding portion is an FPCB, and the overlapping portion is a hard metal or a soft material; when the overlapping portion is made of hard metal, it is overlapped and fixed by hot pressing and serves as the wiring pin.

3. The FPCB rolled voice coil according to claim 1, characterized in that: The conductive layer is formed inside the insulating base layer or on the end surface of the insulating base layer; the conductive layer adopts a double-layer structure and is staggered.

4. The FPCB rolled voice coil according to claim 1, characterized in that: The skeleton is cylindrical or prism-shaped.

5. A method for manufacturing a rolled FPCB voice coil, characterized in that: The manufacturing method is used to manufacture the FPCB rolled voice coil as claimed in any one of claims 1 to 4, and comprises: S100, assuming that the number of insulating base layers having a preset thickness value is at least two groups, preparing a conductive layer for each group of the insulating base layers to obtain an insulating base layer having the conductive layer; S200, stacking the groups of insulating base layers with conductive layers parallel to each other, and aligning one end of the insulating base layers of each group to be stacked and fixed as a whole, and arranging the other end along a straight line direction; S300, starting from one end of each group of insulating base layers aligned and overlapped, each group of insulating base layers is concentrically wound around the outer wall of the preset frame with the axial direction of the preset frame as the center; S400, electrically connecting the connection pin to a preset audio signal transfer circuit; Among them, the edge of the insulating base layer with the conductive layer has wiring pins electrically connected to the conductive layer; when concentrically wound and wrapped, the length values ​​of each group of the insulating base layers are in an arithmetic progression, and the length values ​​are determined by the radius of the preset skeleton and the thickness value.

6. A method for manufacturing a rolled FPCB voice coil, characterized in that: The manufacturing method is used to manufacture the FPCB rolled voice coil as claimed in any one of claims 1 to 4, and comprises: S100, assuming that the number of insulating base layers is one group, preparing a conductive layer on the insulating base layers to obtain an insulating base layer with the conductive layer; S200, gluing or electrostatically treating the insulating base layer with the conductive layer; S300, winding and coating the insulating base layer after glue coating on the outer wall of the preset skeleton with at least two layers around the axial direction of the preset skeleton, and the cross section of the insulating base layer after the overall winding and coating is spiral; S400, electrically connecting the connection pin to a preset audio signal transfer circuit; Wherein, the edge of the insulating base layer with the conductive layer has a connection pin electrically connected to the conductive layer.

7. The method for manufacturing a rolled FPCB voice coil according to claim 5, characterized in that: The step of aligning and stacking one end of each group of insulating base layers and fixing them as a whole comprises: One end of each group of insulating base layers is aligned, overlapped and fixed as a whole by means of gluing or ultrasonic welding.

8. The method for manufacturing a rolled FPCB voice coil according to claim 5, characterized in that: The method of concentrically winding each group of insulating base layers around the outer wall of the preset frame with the axial direction of the preset frame as the center comprises: The outer wall of the preset frame is concentrically wound and coated by means of adhesive or ultrasonic welding.

9. The method for manufacturing a rolled FPCB voice coil according to claim 5, characterized in that: The step of aligning and stacking one end of each group of insulating base layers and fixing them as a whole comprises: The overlapping parts of each group of the insulating base layers are stacked and glued to fix, and the winding parts of each group of the insulating base layers are stacked and aligned and then arranged in a straight line direction.

10. The method for manufacturing a rolled FPCB voice coil according to claim 5 or 6, characterized in that: The step of preparing a conductive layer for each group of the insulating base layers comprises: The conductive layer is formed on the insulating base layer by any one of laser engraving, electroplating and etching.

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