Anti-power-frequency microphone

Abstract

The utility model discloses an anti-power-frequency microphone, and the microphone comprises a microphone unit which is provided with a circuit board as a front surface; the metal foil covers the circuit board and is in conformal fit with the circuit board; and the adhesive is arranged between the circuit board and the metal foil. According to the anti-power-frequency microphone provided by the invention, the metal foil covers the circuit board of the microphone unit, and the metal foil and the circuit board are conformally attached, so that the anti-power-frequency interference of the microphone unit can be better realized. The design is suitable for an electret microphone with a small size and a limited circuit space, especially a unidirectional microphone product.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of microphones, in particular to an anti-power-frequency microphone. BACKGROUND

[0002] The working principle of an electret condenser microphone is based on the charging and discharging principle of a capacitor. It uses an electret film as a vibrating diaphragm. When a sound wave acts on the vibrating diaphragm, it will cause the distance between the vibrating diaphragm and the metal plate to change, thereby changing the capacity of the capacitor. Since the amount of charge on the electret remains unchanged, the change in the capacity of the capacitor will cause a change in the voltage across the capacitor, thereby realizing sound-to-electricity conversion.

[0003] The working of an electret condenser microphone can be affected by power frequency interference. Power frequency interference mainly comes from 50Hz or 60Hz alternating current signals in the power system. This interference signal can enter the microphone through electromagnetic induction or conduction, etc., causing the sound pickup quality to decrease. Power frequency interference appears as a continuous, periodic noise in the microphone output signal, seriously affecting the clarity and purity of the sound pickup.

[0004] Therefore, measures against power frequency interference need to be considered in the design of an electret condenser microphone. Since the size of an electret microphone is small, the circuit space is limited, and it is difficult to design against power frequency interference for an electret microphone. CONTENT OF THE INVENTION

[0005] The application mainly solves the technical problem of providing an anti-power-frequency microphone.

[0006] The anti-power-frequency microphone provided by the application comprises: a microphone unit having a circuit board; a metal foil covering the circuit board and conformally attached to the circuit board; and an adhesive disposed between the circuit board and the metal foil.

[0007] In some optional embodiments, the circuit board has a sound inlet hole, and the metal foil is provided with a through hole corresponding to the position of the sound inlet hole.

[0008] In some optional embodiments, the anti-power-frequency microphone further comprises a wire having a metal shielding layer, and the metal shielding layer is electrically connected to the metal foil.

[0009] In some optional embodiments, the wire further comprises two signal lines covered by the metal shielding layer, and the two signal lines are welded to the circuit board by solder.

[0010] In some optional embodiments, the part of the metal foil covering the solder conforms to the solder.

[0011] In some alternative embodiments, a metal shell is further included, an edge of the metal shell forms a bent portion that presses against the circuit board, and a portion of the metal foil that is above the bent portion is conformal with the bent portion.

[0012] In some alternative embodiments, an edge of the metal foil is recessed relative to an edge of the microphone unit.

[0013] In some alternative embodiments, the metal foil and the microphone unit are insulated by the adhesive.

[0014] In some alternative embodiments, a silica gel sleeve that houses the microphone unit is further included, and the silica gel sleeve has an opening that exposes the circuit board.

[0015] In some alternative embodiments, the microphone unit is a single-directional microphone.

[0016] From the above technical solutions, the embodiments of the present application have the following advantages:

[0017] The anti-power-frequency microphone of the present application covers a metal foil above a circuit board of a microphone unit, and the metal foil is conformal with the circuit board, so that the anti-power-frequency interference for the microphone unit can be preferably achieved. This design is suitable for electret microphones with small size and limited circuit space, especially single-directional microphone products. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments and the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0019] Figure 1 is a longitudinal sectional view of an anti-power-frequency microphone according to an embodiment of the present application;

[0020] Figure 2 is a top view of an anti-power-frequency microphone according to an embodiment of the present application;

[0021] Figure 3 is a bottom view of an anti-power-frequency microphone according to an embodiment of the present application;

[0022] Figure 4 is a top view of a metal foil of an anti-power-frequency microphone according to an embodiment of the present application;

[0023] Figure 5 is a top view of a circuit board of an anti-power-frequency microphone according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0025] The terms "first", "second", "third", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish different objects, and are not used to describe a particular order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0026] The following will be described in detail through specific embodiments.

[0027] Reference Figures 1 to 5 One embodiment of the present application provides an anti-power frequency microphone, comprising:

[0028] A microphone unit 10 having a circuit board 11 as a front face;

[0029] A metal foil 20 covering above the circuit board 11 and conformally attached to the circuit board 11;

[0030] An adhesive 30 arranged between the circuit board 11 and the metal foil 20.

[0031] In some optional embodiments, the metal foil 20 can be a conductive copper foil, and the adhesive 30 can be, for example, a 3M adhesive.

[0032] In some optional embodiments, the microphone unit 10 is a single-directional microphone, the circuit board 11 has a sound inlet hole 12, and the metal foil 20 is provided with a through hole 21 corresponding to the position of the sound inlet hole 12 so that sound can pass through. Optionally, the sound inlet hole 12 can have two or more, and the through hole 21 can have two or more correspondingly.

[0033] In some optional embodiments, the anti-power frequency microphone of the present application further comprises a wire 50 with a metal shielding layer 51, and the metal shielding layer 51 is electrically connected to the metal foil 20 by, for example, welding or the like. In this way, the client can be welded to the ground of the mainboard.

[0034] In some alternative embodiments, the wire 50 is a two-core shielded wire, further comprising two signal wires 52 covered by the shield metal layer 51, and the two signal wires 52 are soldered on the circuit board 11 by the solder 13 (soldered on the positive and negative soldering points of the circuit board 11 respectively). The solder 13 can be protruded on the circuit board 11 to be hemispherical or close to hemispherical.

[0035] In some alternative embodiments, the part of the metal foil 20 covering the solder 13 is conformal to the solder 13.

[0036] In some alternative embodiments, the anti-power-frequency microphone of the present application further comprises a metal shell 14, the edge of the metal shell 14 is inwardly formed to be a bent part pressing on the circuit board 11, and the part of the metal foil 20 covering the bent part is conformal to the bent part.

[0037] In some alternative embodiments, the edge of the metal foil 20 is inwardly recessed relative to the edge of the microphone unit 10. In other words, the diameter of the metal foil 20 is not greater than the diameter of the microphone unit 10.

[0038] In some alternative embodiments, the adhesive 30 is an insulating material, and the metal foil 20 and the microphone unit 10 are insulated and separated by the adhesive 30.

[0039] In some alternative embodiments, the anti-power-frequency microphone of the present application further comprises a silica gel sleeve 40 accommodating the microphone unit, and the silica gel sleeve 40 has an opening exposing the circuit board 11. The silica gel sleeve 40 can be a cylindrical shape with one end open, and is sleeved on the microphone unit 10 from the bottom end (the end opposite to the circuit board 11) of the microphone unit 10, so that the circuit board 11 of the microphone unit 10 is exposed.

[0040] As described above, the present application discloses an anti-power-frequency microphone, by covering the metal foil 20 on the circuit board 11 of the microphone unit 10 through the adhesive 30, and the metal foil 20 is conformal to the circuit board 11, so that the anti-power-frequency interference for the microphone unit can be preferably realized. This design is suitable for the electret microphone with small size and limited circuit space, especially the single-directional microphone product. The circuit board 11 of the single-directional microphone generally has a sound hole, resulting in limited circuit space. By using the scheme of the present application, the metal foil is attached on the circuit board 11 by the adhesive 30, so that the electromagnetic shielding can be preferably realized, the power-frequency interference can be avoided, and the falling off can be prevented.

[0041] The technical solutions of the present application are described in detail through specific embodiments. In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0042] It should be understood that the above-described embodiments are merely intended to illustrate the technical solutions of the present application, but not to limit the same. A person skilled in the art can make modifications to the technical solutions described in the above-described embodiments, or make equivalent replacements to some of the technical features; and the modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and protection scope of the technical solutions of the embodiments of the present application.

Claims

1. A power frequency resistant microphone, characterized in that, include: The microphone unit has a circuit board; A metal foil is placed over the circuit board and conformally adhered to the circuit board. An adhesive is disposed between the circuit board and the metal foil; A wire with a metal shielding layer electrically connected to the metal foil.

2. The anti-power frequency microphone according to claim 1, characterized in that, The circuit board has a sound inlet hole, and the metal foil has a through hole corresponding to the position of the sound inlet hole.

3. The anti-power frequency microphone according to claim 1, characterized in that, The conductor also includes two signal lines covered by the metal shielding layer, which are soldered to the circuit board.

4. The anti-power frequency microphone according to claim 3, characterized in that, The portion of the metal foil covering the solder conforms to the solder.

5. The anti-power frequency microphone according to claim 1, characterized in that, It also includes a metal casing, the edge of which forms a bend that presses against the circuit board, and the portion of the metal foil covering the bend that conforms to the bend.

6. The anti-power frequency microphone according to claim 1, characterized in that, The edge of the metal foil is recessed relative to the edge of the microphone unit.

7. The anti-power frequency microphone according to claim 1, characterized in that, The metal foil and the microphone unit are insulated and isolated by the adhesive.

8. The anti-power frequency microphone according to claim 1, characterized in that, Also includes: A silicone sleeve housing the microphone unit, the silicone sleeve having an opening that exposes the circuit board.

9. The anti-power frequency microphone according to claim 1, characterized in that, The microphone unit is a unidirectional microphone.

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