KR20070089429A - Micro speaker - Google Patents

Abstract

A micro speaker is provided to output a sound without distortion due to interference and to increase an output by securing maximum vibrating amplitude of a diaphragm. A micro speaker includes a magnetic circuit and a case(11). The magnetic circuit includes a diaphragm. The diaphragm includes a yoke, a magnet, a top plate, and a voice coil on one side. The case(11) accommodates the magnetic circuit and includes a terminal for connecting the voice coil to the outside and is blocked by a grill at one side. An interference prevention part prevents the voice coil and the diaphragm from being interfered when the diaphragm vibrates. A supporting unit(11b) forms a gap on a bottom surface to guide an air flow smoothly.

Description

Micro speaker {Micro speaker}

1 is a cross-sectional view showing a conventional package form.

Figure 2a, b) is a cross-sectional view showing a portion interfered with the conventional vibration plate vibration.

Figure 3 is a plan view showing a conventional grill form.

Figure 4 is a perspective view showing the configuration of the present invention.

5 is a perspective view showing a bottom configuration of the present invention.

Figure 6 is an exploded perspective view showing the configuration of the present invention.

Figure 7 is a cross-sectional view showing the package form of the present invention.

8 is a sectional view showing a vibration state of the present invention.

9 is a plan view showing a state in which the terminal of the present invention is impregnated in the case and injection molded.

10 is a schematic diagram illustrating a grill mounting state of the present invention.

      <Description of Signs of Major Parts of Drawings>

10: micro speaker 11: case

11a: interference prevention part 11b: support part

11c: central protrusion 11d: outer support

11e: projection 12: magnetic circuit

13: York 14: magnet

15: top plate 16: voice coil

17: diaphragm 18: terminal

18a: External connection terminal 18b: Terminal connection terminal

19: Grill 1: PCB

2: PCB terminal 3: Mold protrusion

The present invention relates to a micro speaker, and more particularly, to a micro speaker that is embedded in an electronic device and outputs sound according to an input electric signal.

Generally, a speaker is a device that converts an input frequency signal into a sound and outputs the sound. The loudspeaker converts electrical energy into mechanical energy by a voice coil existing between voids by Fleming's left-hand law that a current-carrying conductor is subjected to a force when it is in a magnetic field. That is, when a current signal including several frequencies is applied to the voice coil, the voice coil generates mechanical energy according to the strength of the current and the magnitude of the frequency. Then, the diaphragm attached to the voice coil is vibrated, and ultimately, a sound pressure of a predetermined magnitude that the human ear can recognize is generated.

Among these sound pressures, relatively low sound pressures are used to closely adhere to the human ear and are commonly referred to as receivers. In contrast, those with relatively high sound pressure and a certain distance from the human ear are used as speakers. It is called. The magnetic circuit of such a speaker uses magnetic magnets and top plates in a metal yoke to cross magnetic flux at right angles to the voice coils present in the air gap. It is designed to be. At this time, the voice coil is bonded to the diaphragm, and generates an up and down excitation force by the input signal, and vibrates the diaphragm adhesively bound to the frame to generate a sound pressure. The diaphragm has various shapes of waves in order to remove the buckling phenomenon and excellent response during the up and down oscillation, and the shape of the diaphragm serves as a design variable that has the greatest influence on the frequency characteristics. Such a speaker has not changed much in its structure for a long time, but in recent years, in response to the commercialization of high-energy permanent magnets, the development of molding technology for microstructures, and the miniaturization and light weight in the information and communication field, continuous reduction in size and performance In this technology development, the miniaturization of the speaker and electronic devices including the same has been an obstacle to the improvement of the output characteristics of the speaker. In other words, in the miniaturization and slimming, the magnetic circuit provided inside the speaker is also miniaturized, and it is difficult to expect an improvement in output characteristics without development and improvement of the structure of the device constituting the magnetic circuit.

Recently, as shown in Figure 1 of the accompanying drawings, in order to improve the workability, a structure in which the magnet is impregnated injection molding has been introduced, but such a conventional micro speaker is to connect the terminal of the voice coil to the outside In addition to adhesively install a PCB formed with a separate pattern, and solder connection between the terminal of the voice coil and the external connection wiring, there is a problem in the cumbersome and workability of the manufacturing process, such as the connection is not made correctly in the process.

In addition, in the conventional micro speaker, as shown in (a) and b) of the accompanying drawings, when the vibration plate vibrates, the terminal drawn out of the diaphragm or voice coil is interfered with the inner step of the case, so that the output characteristics are distorted or degraded. There was a problem.

In addition, in the conventional micro-speaker as shown in Figures a) and b) of the accompanying drawings, a plurality of through-holes formed in the grill was formed in the center or the center and the center around the center, but this is an automatic using a mounting device Impossible assembly was an obstacle to the automation of the manufacturing process.

The present invention for solving the above problems, while aiming at a light and small short, while increasing the magnetic force of the magnetic circuit, and improving the diaphragm seating structure, so as not to interfere with the vibration, while improving the output characteristics, the grill By securing a pick-up area on the surface, the mounting can be mechanically carried out during the assembly process, and the shape of the thin plastic sheet is formed above the reflow temperature, thereby preventing the appearance of the diaphragm from being deformed during the reflow process. The present invention aims to provide a micro speaker that allows the manufacturing process to be carried out by a mechanical automatic process.

The present invention for achieving the object is composed of a magnetic circuit consisting of a diaphragm provided on one side of the yoke, magnet, top plate, boy coil and a case containing the terminal for connecting the terminal of the voice coil to the outside In the micro-speaker, the case impregnated to accommodate the magnet and the terminal in the form of a package through the injection molding, the interference preventing unit for preventing the vibration plate and the voice coil from interfering with the inner surface during the vibration of the diaphragm; and the exposed to the outside The external connection terminal of the terminal and the terminal of the PCB to be in close contact, but support portion for forming a clearance on the lower surface to induce a smooth air flow; characterized in that it comprises a further configuration.

In the present invention, the magnet and terminal, that is, the terminal connection terminal to which the terminal of the voice coil is connected and the external connection terminal connected to the external PCB terminal are impregnated and molded integrally during the case injection molding. The step of assembling the terminals can be omitted, which greatly reduces the manufacturing process.

In addition, according to the present invention, the diaphragm seating step of the inside of the case is lowered by slimming the case. At this time, the interference preventing part, for example, a notch groove is formed on the path where the voice coil is guided, and the voice coil is vertically vibrated. Since interference with the inner surface of the case is prevented, the amplitude of the diaphragm can be secured to the maximum, and the sound can be output without distortion due to the interference.

In addition, when mounting on the PCB, the support unit supports the external connection terminal exposed on the lower surface of the case and the terminal of the PCB to maintain the same state, and at the same time, the parts other than the supported portion to be spaced apart from the surface of the PCB. When the diaphragm vibrates, the air flowing in and out flows smoothly through the hole formed in the clearance part.

As described in the accompanying drawings, which is a reference for explaining the present invention before explaining the present invention in detail, Figure 4 is a perspective view showing the configuration of the present invention, Figure 5 is a separate perspective view showing the configuration of the present invention, Figure 6 is a cross-sectional view showing the package form of the present invention, Figure 7 is a plan view showing the position of the interference prevention portion of the present invention, Figure 8 is a cross-sectional view showing the vibration state of the present invention, Figure 9 of the present invention 10 is a plan view showing a state in which the terminal is impregnated in the case and injection molded, and FIG. 10 is a schematic view showing the mounting state of the grill according to the present invention. The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are defined in the technical spirit of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term in order to explain his invention in the best way. It must be interpreted to mean meanings and concepts.

First, the present invention, as shown in the accompanying drawings, Figures 4 to 6, the yoke 13, the magnet 14, the top plate 15, the magnetic coil consisting of a diaphragm 17 provided on one side A micro speaker comprising a circuit 12 and a terminal 18 for accommodating the same, and a terminal 18 for connecting the terminal of the voice coil 16 to the outside, and one side of the open surface is blocked by the grill 19. In (10), the case 11 is impregnated to accommodate the magnet 14 and the terminal 18 in the form of a package through injection molding, the vibration plate 17 and the voice coil 16 during the vibration of the diaphragm 17 Interference prevention unit (11a) to prevent the interference on the inner surface; and the external connection terminal (18a) and the terminal 2 of the PCB (1) of the terminals 18 exposed to the outside to support close, but smooth It is configured to further include; a support portion (11b) for forming a clearance on the lower surface to induce air flow.

Here, the case 11 of the present invention may further include, for example, further impregnated with the top plate 15 and the yoke 13 stacked on both sides of the magnet 14, respectively. In this way, the assembly manufacturing process can be further simplified. That is, when the diaphragm 17 is seated on the case 11, the grille is covered, and the terminal of the voice coil 16 is soldered and connected to the terminal, the micro speaker 10 is assembled. For reference, a conventional micro speaker manufacturing process includes mounting a yoke on a case, a magnet on a yoke, a top plate on a magnet, attaching a diaphragm to a case, covering a grill, and covering a terminal of a voice coil to a terminal. It was a multi-step process for soldering connections. Therefore, it can be seen that the present invention greatly reduced the manufacturing process of the micro speaker.

In addition, the interference preventing portion 11a of the case 11 is, for example, as shown in FIG. 7, for example, a part of the inner surface of the case 11 on which the diaphragm 17 is seated, that is, the voice coil 16. It may be a home made by cutting off a part of a path from which the terminal is drawn out. In this case, as shown in FIG. 8, the amplitude of the diaphragm 17 and the voice coil 16 is secured to the depth of the groove, and even if a large amplitude occurs, the inner surface of the case 11 is not interfered with. The sound can be output while vibrating.

In addition, the support 11b of the case 11 may include, for example, a central protrusion 11c protruding from the center of the lower surface of the case 11 and an outer edge protruding outward while protruding higher than the central protrusion 11c. It may be composed of a branch (11d). In this case, the outer support part 11d may be formed at four corners or at four sides. Here, any one of the outer support part 11d may be formed at the same height as the center protrusion part 11c, and a protrusion 11e may be formed on the lower surface to have the same height as the other outer support part 11d. At this time, on the lower surface of the outer support portion 11d except for the outer support portion on which the protrusion 11e is formed, an external connection terminal 18a of the terminal 18 is drawn out and bent outward to form a connection surface. It is bent to extend to the side height of the case (11). As described above, the terminal 18 is connected to one of the terminal connection terminal 18b and one of the external connection terminals 18a impregnated in the case, as shown in FIG. The other terminal of the terminal connection terminal 18b and the other of the external connection terminal 18a are connected in a state of being impregnated in the case, thereby becoming an electrically conductive state. In this case, the micro speaker 10 of the present invention is not connected to the terminal of the PCB through manual soldering, but is soldered through a reflower, thereby shortening the manufacturing process and improving workability and productivity.

In addition, the outer support portion 11d uniformly supports only the area to be soldered without occupying a large area of the lower surface of the case 11, thereby preventing flow during reflow, and lower surface of the case 11 Protruding from the through-hole formed in the, to allow the air flow smoothly through the through and out of the case.

In addition, as shown in FIG. 9, even when the terminal 18 is fixed during the case 11 injection, the peripheral edge of the terminal cell is inserted into the mold protrusion 3 that forms the through hole of the case 11. By maintaining the position, accurate injection molding is achieved.

Meanwhile, in the present invention, the yoke 13 may be a flat plate or a cap shape with a protruding center. Here, when the yoke 13 is a flat plate, a separate magnet 14a and a top plate 15a may be laminated at intervals with the magnet 14 at the center thereof. In this case, the magnetic force of the magnetic circuit 12 is increased to improve the amplitude.

On the other hand, the magnet 14 of the present invention, for example, the material is Nd (neodymium) and Fe (iron) as a main component, Co (cobalt) is a metal material added. Magnat 14 of the present invention having such a material has the advantage of excellent heat resistance and low cost. Conventionally, although Nd and Fe are the main components, B (boron) was added, but this had a problem of extremely low heat resistance.

Further, in the present invention, the material of the yoke 13 and the top plate 15 is, for example, an alloy containing Ni (nickel) and Fe (iron) as its main component, that is, permalloy. In this way, the yoke 13 and the top plate 15 of the present invention having a material can reduce the thickness of the magnet. In other words, the alloy of nickel and iron (PERMALLOY) has a higher magnetic permeability than iron, and can transmit the magnetic force of the magnet well to increase the magnetic force in the gap of the coil of the vibrating unit to move up and down. If the force (electromagnetic force) received by the conductor (COIL) through which current flows in the magnetic field (GAP) increases, the sound pressure (SPL) of the speaker may increase.

For reference, the speaker follows Fleming's left-hand law, and when F = BIL, the electric force is increased by the magnetic force when the current and the conductor are the same length.

In addition, the ratio of nickel varies from 35 to 90% depending on the use, but the alloy used in the present invention is an alloy containing 42-45% of nickel. Experimental data (magnetic field comparison) comparing the present invention and the conventional SPC (pure iron) is shown as shown below.

1) If the thickness of permoloy is 0.2T,

2) If the thickness of SPC (pure iron) is 0.2T,

3) If the thickness of permolloy is 0.6 and 0.3T,

4) If the thicknesses of SPC are 0.6 and 0.3T,

On the other hand, in the present invention, the diaphragm 17 is, for example, PI (Poly Imide; Polyamide), the molding temperature range is preferably 260 ~ 310 ℃. Since the reflow temperature range is about 240 to 260 ° C, when the diaphragm is formed at the temperature below or within the range, the original shape is lost during the reflow process, causing a big problem in the output characteristics. Because it becomes. For reference, the molding temperature range of the conventional diaphragm was 170 to 220 ° C.

On the other hand, in the present invention, the grill 19, for example, it is preferable that the through-hole is formed only in the portion except the center so that the mounting apparatus can pick up. At this time, the shape and the number of the through holes can be deformed or reduced as necessary. In this case, as shown in the accompanying drawings, Figure 10, the automatic assembly is made using the mounting device to the grill 19 rather than manual.

In the present invention, the magnet 14 and the terminal 18, ie, the terminal connection terminal 18b to which the terminal of the voice coil 16 is connected, and the external connection terminal 18a to be connected to the external PCB terminal 2 are provided. Since the case is impregnated and integrally molded at the time of injection molding, the process of assembling the magnet 14 and the terminal 18 in a separate manufacturing process can be omitted.

In addition, according to the present invention, the mounting step of the diaphragm 17 inside the case 11 is lowered through the slimming of the case 11. In this case, the interference prevention part 11a is formed on the path where the voice coil 16 is guided. For example, the notch groove is formed, and when the vertical vibration, the terminal of the voice coil 16 can be prevented from interfering with the inner surface of the case (11).

In addition, when mounting on the PCB, while supporting the external connection terminal exposed to the lower surface of the case and the terminal of the PCB to maintain the same state, and at the same time, the parts other than the supported portion to be spaced apart from the surface of the PCB In addition, through the opening formed in the clearance part, the inflow and outflow air during the vibration of the diaphragm can flow smoothly.

In addition, a through hole is formed only in a portion except the center of the grill 19, and the grill 19 can be fitted and fixed to the case 11 by using a mounting apparatus rather than a manual operation.

In this way, the present invention is simply and automatically made to mount the diaphragm 17 and the grille 19 seated in the case 11 through the mounting device, the connection with the terminal 2 of the PCB (1) of the electronic device It can also be done automatically by reflow.

As described above, the micro speaker of the present invention is capable of various modifications in addition to those shown and described, and the embodiments to be modified should be interpreted as being included in the scope of the present invention without departing from the scope of the present invention.

According to the present invention, the magnet 14 and the terminal 18, that is, the terminal connection terminal 18b to which the terminals of the voice coil 16 are connected, and the external connection terminal 18a to be connected to the external PCB terminal 2 are provided. ) Is impregnated and molded integrally during the case injection molding, so the process of assembling the magnet 14 and the terminal 18 can be omitted in a separate manufacturing process, greatly reducing the manufacturing process, Get the effect of making it happen.

In addition, according to the present invention, the mounting step of the diaphragm 17 inside the case 11 is lowered through the slimming of the case 11. In this case, the interference prevention part 11a is formed on the path where the voice coil 16 is guided. For example, a notch groove is formed, and thus the terminal of the voice coil 16 is prevented from interfering with the inner surface of the case 11 during vertical vibration, thereby ensuring the maximum amplitude of the vibration 17 plate. The output power can be increased, and the sound can be output without distortion due to interference.

In addition, when the PCB is mounted on the PCB, the support part supports the external contact terminal exposed on the bottom surface of the case and the terminal of the PCB to be kept in a coincidence state, and at the same time, the parts other than the supported part are spaced apart from the surface of the PCB. Thus, the air flowing in and out of the vibration plate vibrates through the through hole formed in the clearance part, so as to smoothly flow.

In addition, by forming a through hole only in the portion except the center of the grill 19, the grill 19 can be fitted to the case 11 by using a mounting device rather than a manual operation, the automatic assembly is made, The productivity improvement effect is obtained.

Claims (11)

A magnetic circuit 12 composed of a diaphragm 17 having a yoke 13, a magnet 14, a top plate 15, and a voice coil 16 provided on one side thereof, and containing the terminal, of the voice coil 16 Terminal 18 is connected to the outside, and one side of the open surface of the micro speaker 10 consisting of a case 11 is blocked by the grill 19, the case 11 through the injection molding package Impregnating and accommodating the magnet 14 and the terminal 18 in the form, but the interference preventing portion (11a) to prevent the vibration plate 17 and the voice coil 16 from interfering with the inner surface when the diaphragm 17 vibrates; and A support part (11b) supporting the external connection terminal (18a) and the terminal (2) of the PCB (1) to be in close contact with each other exposed to the outside, to form a gap on the lower surface to induce a smooth air flow; Micro speaker further comprises a. The micro speaker according to claim 1, wherein the case (11) further comprises an impregnation with a top plate (15) and a yoke (13) laminated on both sides of the magnet (14), respectively. The method of claim 1, wherein the interference preventing portion (11a) of the case 11 is composed of a groove made by cutting a part of the path that the voice coil 16 terminal of the case 11 is drawn out on which the diaphragm 17 is seated. Micro speaker characterized in that. According to claim 1, wherein the support portion (11b) of the case 11 is a central projection (11c) protruding in the center of the lower surface of the case 11; and protrudes higher than the central projection (11c) to extend outwardly Outer support portion (11d); Micro speaker characterized in that consisting of. 5. The micro speaker according to claim 4, wherein the outer support part (11d) is formed at a corner in four directions. 5. The protrusion 11e of claim 4, wherein any one of the outer support parts 11d is formed at the same height as the center protrusion part 11c, and the protrusions 11e are formed on the lower surface of the outer support part 11d to have the same height as the other outer support parts 11d. Micro speaker characterized in that the configuration. The micro speaker of claim 1, wherein the magnet (14) is composed of Nd and Fe as main components, and is made of an alloy to which Co is added. The micro speaker according to claim 1, wherein the yoke (13) and the top plate (15) are made of permolloy, which is an alloy containing Ni and Fe as main components. 9. The micro speaker of claim 8, wherein the proportion of Ni (nickel) is 42-45% in the alloy. The micro speaker according to claim 1, wherein the diaphragm is made of PI and molded at a molding temperature of 260 to 310 ° C. The micro speaker according to claim 1, wherein the grill (19) is formed so that a hole is formed only in a portion except the center so that the mounting apparatus can pick up.

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