WO2010051707A1

WO2010051707A1 - Silicon microphone

Info

Publication number: WO2010051707A1
Application number: PCT/CN2009/073215
Authority: WO
Inventors: 宋青林; 庞胜利; 谷芳辉; 宋锐锋
Original assignee: 歌尔声学股份有限公司
Priority date: 2008-11-07
Filing date: 2009-08-12
Publication date: 2010-05-14
Also published as: CN101426166A

Abstract

A silicon microphone includes: a casing; a circuit board set on the bottom of the casing; a first sound hole provided on the circuit board; a piece body fixed on the upper surface of the circuit board; a second sound hole on the piece body together with the first sound hole staggered by a certain distance; a silicon microphone chip mounted on the piece body in a position covering the second sound hole; and a first thin sound channel provided between the first sound hole and the second sound hole for communicating both of them. The present invention reduces the probability of a sound hole jam or silicon microphone chip damage, and to a great extent decreases the probability of generation of bad sound effect by providing the thin sound channel; meanwhile, reduces manufacturing costs due to the circuit board composed of single-layer or double-layer base board.

Description

Instruction manual

Technical field

[1] The present invention relates to a silicon microphone, and more particularly to a silicon microphone structure which reduces the possibility of clogging a sound hole or a silicon microphone chip being damaged, and reducing the production cost.

Background technique

[2] In recent years, as the volume of electronic products such as mobile phones and notebook computers has been decreasing, the performance requirements for them have become higher and higher, and the volume of electronic components required has been continuously reduced. The performance and consistency of electronic components. keep improving. In this context, microphone products, one of the important components, have also introduced a number of new products, and silicon microphones that are mass-produced using semiconductor manufacturing processing technology are representative products. In order to meet the installation requirements of electronic products, some silicon microphone products need to open sound holes on the circuit board with electrodes to achieve the "zero height" on the circuit board installed on the electronic equipment (the main body of the silicon microphone is installed in the electronic Below the product circuit board, the height above the electronic product circuit board is not increased, and the general industry refers to the "Bottom" type of product or meets the acoustic properties such as directivity.

[3] Recently, many techniques for opening sound holes on a circuit board with electrodes of a silicon microphone have been disclosed. For example, the specification of Chinese Patent Application No. 200720022592.2 discloses an invention titled "Silicon Microphone with Dustproof Sound Holes" Technical content. The specific structure is as shown in FIG. 1. The silicon microphone 100 includes a square outer casing 101 and a square circuit board 103. The circuit board 103 is composed of a first circuit board 103a, a second circuit board 103b and a spacer layer 103c on the first circuit board 103a. A sound hole 102a is provided, a sound hole 102b is formed in the second circuit board 103b, a hollow 102c is provided on the spacer layer 103c, and a MEMS acoustic chip 104 is mounted above the sound hole 102a. In the above structure, by stacking a plurality of circuit boards provided with openings, an elongated sound passage is formed, which can achieve the dustproof effect of the silicon microphone and can help the silicon microphone resist the solder generated during the solder mounting process. Slag and high temperature suppress the occurrence of problems such as blocking sound holes and damaging MEMS acoustic chips.

[4] However, electronic products such as mobile phones now require silicon microphone parts to have smaller height dimensions, and the technique in the above-mentioned patent application 200720022592.2 requires superimposing a three-layer circuit board substrate if the thickness of the substrate is relatively high. Large, it is bound to cause an increase in the overall height of the silicon microphone; if the thickness of the substrate is too small, the manufacturing process is complicated, resulting in an increase in production costs.

Summary of the invention

[5] The present invention has been made to solve the above problems in the prior art, and an object thereof is to provide a silicon microphone which reduces the possibility of clogging a sound hole or a silicon microphone chip being damaged, and which reduces production cost.

[6] In order to achieve the above object, a silicon microphone provided by the present invention includes: a casing; a circuit board

Mounted on the bottom of the outer casing, the first sound hole is opened on the circuit board; the chip body is disposed on the upper surface of the circuit board, and is provided with a first distance from the first sound hole a sound hole; and a silicon microphone chip disposed above the sheet body and covering the second sound hole; and connecting between the first sound hole and the second sound hole An elongated first sound channel of a sound hole and a second sound hole.

[7] According to the silicon microphone using the above structure, since the elongated first sound passage connecting the first sound hole and the second sound hole is provided, solder slag, dust, moisture, and the like can be prevented from reaching the set position of the silicon microphone chip. Therefore, the possibility that the blocked sound hole or the silicon microphone chip is damaged is reduced, and the generation of bad sound effects is suppressed.

[8] In addition, a preferred structure is that the circuit board includes a first substrate and a second substrate stacked on top of each other, and an elongated long hole is formed in the first substrate of the upper layer as the first sound channel. The first sound hole smaller than the long hole is opened in the second substrate of the lower layer, and the first sound hole, the first sound channel and the second sound hole communicate with each other.

[9] In addition, a preferred structure is that the circuit board is composed of a single-layer substrate on which the first sound hole is opened, and the sheet body has a plane on which the second sound hole is opened. And a curved portion bent vertically downward from the flat portion, and an inner space surrounded by the sheet and the wiring board constitutes the first sound passage.

[10] According to the above configuration, since the wiring board of the silicon microphone is composed of a single layer or a double layer substrate, the production cost of the silicon microphone is lowered.

[11] Further, it is preferable that the first sound hole provided on the sheet body is composed of a plurality of fine holes.

[12] This structure can further improve the dustproof effect, and it is also very easy to make a plurality of fine sound holes on a metal sheet by a process such as punching and etching. [13] Further, preferably, the sheet body further has a horizontal extending portion extending outward from the curved portion in the horizontal direction, and the horizontal extending portion is for coupling with the wiring board.

[14] This structure increases the contact area between the sheet and the board, and the bonding effect and sealing effect are better.

[15] Further, preferably, the circuit board is composed of a single-layer substrate on which the first sound hole is opened; and the sheet body is disposed toward the side of the circuit board There is a horizontal groove as the first sound passage.

[16] According to the above structure, the horizontal groove on the sheet body can be formed by a process such as punching, and the contact area between the circumference of the horizontal groove and the surface of the board is increased, thereby improving the reliability of the joint.

[17] Further, a preferred structure is that a third sound hole is provided on the outer casing. Further, it is preferable that a sound damper is further provided at the third sound hole provided on the outer casing.

[18] With the above structure, a single-point silicon microphone can be realized to further improve the sound effect of the microphone.

Further, it is preferable that a sealing member is provided around the first sound hole on the lower surface of the wiring board.

[20] This structure allows the Bottom-type silicon microphone to be mounted on other boards of electronic equipment.

The airtightness between the circuit board of the silicon microphone and the other circuit boards of the electronic device is better to prevent air leakage.

DRAWINGS

The above features and technical advantages of the present invention will become more apparent and understood from the <RTIgt;

1 is a cross-sectional view showing a specific structure of a silicon microphone according to a related art.

2 is a cross-sectional view showing a specific configuration of a silicon microphone according to the first embodiment of the present invention.

[ Fig. 3] Fig. 3 is an exploded perspective view showing a specific configuration of each of the substrates 23 and 24 and the sheet body 3 in the silicon microphone according to the first embodiment of the present invention.

4 is a cross-sectional view showing a specific configuration of a silicon microphone according to a second embodiment of the present invention.

[ Fig. 5] Fig. 5 is a bottom plan view showing a specific configuration of a sheet body 3 in a silicon microphone according to a second embodiment of the present invention.

6 is a cross-sectional view showing another modified structure of the silicon microphone according to the second embodiment of the present invention. 7 is a bottom view showing a specific structure of a sheet body 3 in another modified structure of the silicon microphone according to the second embodiment of the present invention.

8 is a cross-sectional view showing still another modified structure of the silicon microphone according to the second embodiment of the present invention. [30] FIG. 9 is a view showing still another modified structure of the silicon microphone according to the second embodiment of the present invention. Sectional view

Fig. 10 is a bottom view showing a specific structure of a sheet body 3 in still another modified structure of the silicon microphone according to the second embodiment of the present invention.

11 is a cross-sectional view showing a specific configuration of a silicon microphone according to a third embodiment of the present invention.

FIG. 12 is a bottom view showing a wiring board in a silicon microphone according to a third embodiment of the present invention.

[ Fig. 13] Fig. 13 is a cross-sectional view showing a specific configuration of a silicon microphone according to a fourth embodiment of the present invention.

detailed description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment of a silicon microphone according to the present invention will be described in detail with reference to the accompanying drawings.

[36] (First Embodiment)

2 is a cross-sectional view showing a specific configuration of a silicon microphone according to a first embodiment of the present invention. FIG. 3 is a view showing each of the substrates 23, 24 and the sheet 3 in the silicon microphone according to the first embodiment of the present invention. An exploded view of the specific structure. As shown in FIG. 2 and FIG. 3, the silicon microphone comprises: a casing 1 having a rectangular parallelepiped shape with a bottom; and a circuit board 2 composed of two first substrates 23 and a second substrate 24 of the same size, the two substrates 23 The length and width of the cover 24 are the same as the length and width of the bottom of the outer casing 1. Generally, a resin material is used as the base material of the substrates 23 and 24, and an elongated first long hole 231 is opened in the first substrate 23. a first sound hole 241 having a square shape and smaller than the first long hole 231 is formed in the second substrate 24; a plurality of external electrodes 21 are disposed on the lower surface of the second substrate 24 for using the silicon microphone with the electron The other circuit board of the device is soldered, and the electrical signal of the silicon microphone is transmitted; and the rectangular body 3 is disposed on the upper surface of the first substrate 24, and the small hole of the second sound hole 31 is opened on the sheet body. A silicon microphone chip 4 mounted on the sheet 3 and covering the second sound hole 31; and an IC chip 5 mounted on the upper surface of the first substrate 23.

[38] Here, the outer casing 1 and the wiring board 2 are bonded together to form a square cavity, which becomes a protective structure of the silicon microphone. The first substrate 23 and the second substrate 24 are bonded together, and the first long hole 231 becomes the sound of the silicon microphone The intermediate channel 241 and the second aperture 31 are offset by a certain distance. Thereby, the external sound can be transmitted to the silicon microphone chip 4 through the first sound hole 241, the first long hole 231 as the sound intermediate passage, and the second sound hole 31.

[39] Due to the above structure, when the silicon microphone is soldered on other circuit boards of the electronic device or after the use of the silicon microphone, solder slag, dust, moisture, etc. which are easily generated on the circuit board may affect the performance of the silicon microphone. It is necessary to pass through the elongated first long hole 231 to reach the second sound hole 31 and the silicon microphone chip 4, thereby reducing the possibility that the blocked sound hole or the silicon microphone chip is damaged, and the defect is largely reduced. The possibility of sound effects. Furthermore, the silicon microphone of the present embodiment has only two layers of substrates, and the height of the product is lowered as compared with the silicon microphone structure fabricated using a plurality of layers of wiring boards, so that the processing procedure is further simpler and the production cost is lowered.

[40] (Second embodiment)

In the silicon microphone according to the present embodiment, the structure of the outer casing 1, the external electrode 21, the silicon microphone chip 4, and the ICS sheet _{5 is} the same as that of the first embodiment described above, except that the wiring board 2 and the sheet body are different. The structure of 3. Therefore, the description of the same configuration is omitted here, and the configuration different from the first embodiment will be mainly described.

4 is a cross-sectional view showing a specific configuration of a silicon microphone according to a second embodiment of the present invention. As shown in Fig. 4, the wiring board 2 of the silicon microphone of the present embodiment has a single-layer structure, and only one square and small-area first acoustic hole 22 is opened on the wiring board 2. A plurality of external electrodes 21 are provided on the lower surface of the circuit board 2 for soldering the silicon microphones to other circuit boards of the electronic device and transmitting electrical signals of the silicon microphones.

[5] FIG. 5 is a bottom view showing a specific configuration of the sheet body 3 in the silicon microphone according to the second embodiment of the present invention. As shown in FIG. 4 and FIG. 5, the cross section of the sheet body 3 used in the silicon microphone of the present embodiment has a U-shaped structure, that is, a bent portion that is bent vertically downward from the peripheral edge of the rectangular flat portion, and A second sound hole 31 is opened in a plane portion of the sheet body ₃ . The sheet body 3 is disposed on the upper surface of the circuit board 2 and covers the first sound hole 22 opened in the circuit board 2. A very thin internal space 32 is formed between the circuit board 2 and the body 3, which constitutes a sound intermediate passage of the silicon microphone. Furthermore, the first sound hole 22 on the circuit board 2 and the first sound hole 31 on the sheet body 3 are staggered by a certain distance. Thereby, external sound can be transmitted to the silicon microphone chip 4 through the first sound hole 22, the inner space 32 as the sound intermediate passage, and the second sound hole 31.

[44] The silicon microphone having the above structure can achieve the same effects as the silicon microphone of the first embodiment. Furthermore, since the circuit board 2 has a single layer structure, the structure of the circuit board is further simplified, and the cost is reduced.

[ Fig. 6] Fig. 6 is a cross-sectional view showing another modified structure of a silicon microphone according to a second embodiment of the present invention; and Fig. 7 is a view showing another modified structure of the silicon microphone according to the second embodiment of the present invention. A bottom view of the specific structure of the sheet ₃ .

[46] Compared with the above-described structure of the silicon microphone of the second embodiment, the improved structure is different in that the second sound hole 31 opened in the plane portion of the sheet body 3 is not constituted by one square hole but by A plurality of tiny pores are gathered together to form. This structure can further improve the dustproof effect, and it is also very easy to form a plurality of fine holes on the metal sheet by a process such as pressing and etching.

Further, Fig. 8 is a cross-sectional view showing still another modified structure of the silicon microphone according to the second embodiment of the present invention. In still another modified construction, the sheet body 3 further has a horizontal extension portion 33 extending horizontally outward from the curved portion, the horizontal extension portion 33 being used for bonding with the wiring board 2. According to the silicon microphone of this structure, the contact area between the sheet 3 and the wiring board 2 is increased, so that the bonding effect and the sealing effect are further enhanced.

[ Fig. 9] Fig. 9 is a cross-sectional view showing still another modified structure of the silicon microphone according to the second embodiment of the present invention. Fig. 10 is a view showing still another modified structure of the silicon microphone according to the second embodiment of the present invention. A bottom view of the specific structure of the sheet 3. In this modification, an elongated groove having a predetermined depth is processed by machining or the like along the longitudinal direction of the sheet 3 on the side of the sheet 3 having a predetermined thickness toward the wiring board 2 side. A second sound hole 31 penetrating the sheet body 3 is opened in the groove, and the second sound hole 31 on the sheet body 3 and the first sound hole 22 on the circuit board 2 are disposed at a certain distance. After the sheet 3 is mounted on the wiring board 2, the groove portion forms a very thin internal space 32, which constitutes a sound intermediate passage of the silicon microphone. Thereby, external sound can be transmitted to the silicon microphone chip ₄ through the first sound hole 22, the inner space ₃₂ as the sound intermediate passage, and the second sound hole ₃₁ . By using the sheet body 3 provided with the groove, the contact area of the sheet body 3 with the wiring board 2 is increased, and the reliability of bonding is improved.

[Third embodiment]

[50] In the silicon microphone according to the present embodiment, the structures of the casing 1, the sheet 3, the external electrodes 21, the silicon microphone chip 4, and the IC chip 5 are the same as those of the second embodiment described above, and the difference lies in the line. Increase on board 2 A sealing member is provided. Therefore, the description of the same configuration will be omitted here, and the configuration different from the above embodiment will be emphasized.

[ Fig. 11] Fig. 11 is a cross-sectional view showing a specific configuration of a silicon microphone according to a third embodiment of the present invention. Fig. 12 is a bottom view showing a wiring board in a silicon microphone according to a third embodiment of the present invention. As shown in FIG. 11 and FIG. 12, the circuit board 2 used in the silicon microphone according to the present embodiment is provided with, for example, a circular first acoustic hole 22, and on the lower surface of the circuit board 2, around the first The sound hole 22 is provided with an annular sealing member 6. Here, the sealing member 6 is made of, for example, a rubber or resin type sealing yoke, and may be composed of a ring-shaped welding pad or a bismuth adhesive, and its height is equivalent to the height of the external electrode 6.

[52] In the present embodiment, the structure of the silicon microphone is illustrated by taking a circular first sound hole and a circular sealing member as an example, but those skilled in the art should understand that the first sound hole and the sealing member The shape is not limited to a circle or a ring, and may be, for example, a square, a polygon, an ellipse or the like.

[53] According to the silicon microphone according to the third embodiment as described above, since the sealing member 6 is provided, the Bottom type silicon microphone can be mounted to other circuit boards of the electronic device, and the circuit board 2 of the silicon microphone is ensured. Air tightness between other boards of electronic equipment to prevent air leakage.

[Fourth Embodiment]

[55] In the silicon microphone according to the present embodiment, the structures of the casing 1, the sheet 3, the external electrodes 21, the silicon microphone chip 4, and the IC chip 5 are the same as those of the second embodiment described above, with the difference that A third sound hole 11 is also formed in the outer casing 1. The description of the same configuration will be omitted here, and the configuration different from the above embodiment will be emphasized.

FIG. 13 is a cross-sectional view showing a specific configuration of a silicon microphone according to a fourth embodiment of the present invention. As shown in FIG. 13, the outer casing 1 of the silicon microphone according to the fourth embodiment is constituted by a cover 12 and a square frame 13, on which a third sound hole 11 is opened, and on the lower surface of the cover 12. An acoustic damper device 7 covering the third sound hole 11 is attached, and the sound damper device 7 can be made of a material such as a sponge.

According to the configuration as described above, a single-directional silicon microphone can be realized by providing the third sound hole 11 and the sound damping device 7 on the cover 12 of the silicon microphone.

In the present embodiment, although the outer casing 1 has been described as being constituted by the cover 12 and the square frame 13, it is needless to say that the outer casing 1 may have the same integral structure as the first to third embodiments. [59] In summary, in the silicon microphone according to the present invention, since an elongated sound intermediate passage is provided, it is difficult to cause solder slag, dust, moisture, and the like which may easily affect the performance of the silicon microphone on the circuit board. The position of the second sound hole or the silicon microphone chip is reached, thus reducing the possibility of clogging the sound hole or the silicon microphone chip being damaged. Furthermore, the circuit board 2 is composed of a single-layer or double-layer substrate, which reduces the height dimension and reduces the cost as compared with the silicon microphone structure of the conventional three-layer circuit board.

[60] In the above embodiments of the present invention, both the outer casing and the wiring board are square, but it is needless to say that the outer casing and the wiring board may be of other shapes such as a circular shape or an elliptical shape. Further, the material of the outer casing is preferably made of a metal material, but a resin material may also be used. Further, in the above description, the first sound hole, the second sound hole, and the third sound hole have been described as an example, but the shapes of the sound holes may be other shapes such as a polygon, a circle, and a square.

Although the specific embodiments of the present invention have been described above with respect to the specific structure of the silicon microphone, those skilled in the art can make various improvements and modifications based on the above embodiments under the above teachings of the present invention. Improvements or modifications fall within the scope of the invention. It should be understood by those skilled in the art that the foregoing detailed description is only for the purpose of explanation of the invention. The scope of the invention is defined by the claims and their equivalents.

Claims

Claim

[1] 1. A silicon microphone, comprising:

Outer casing

a circuit board, mounted on the bottom of the outer casing, a first sound hole is formed on the circuit board; a chip body is disposed on the upper surface of the circuit board, and is disposed at a distance from the first sound hole Second sound hole;

a silicon microphone chip disposed above the sheet body and covering the second sound hole; between the first sound hole and the second sound hole, a first sound hole and a first sound hole are further provided An elongated first sound channel of the second sound hole.

[2] 2. The silicon microphone according to claim 1, wherein

The circuit board includes a first substrate and a second substrate stacked on top of each other, and an elongated long hole is formed in the first substrate of the upper layer as the first sound channel, and is opened on the second substrate of the lower layer The first sound hole is smaller than the long hole, and the first sound hole, the first sound channel and the second sound hole communicate with each other.

[3] 3. The silicon microphone according to claim 1, wherein

The circuit board is composed of a single-layer substrate on which the first sound hole is opened; the sheet body has a flat portion in which the second sound hole is opened and vertically downward from the flat portion The bent portion, the inner space surrounded by the sheet and the wiring board constitutes the first sound passage.

[4] The silicon microphone according to any one of claims 1 to 3, wherein

The first sound hole provided on the sheet body is composed of a plurality of fine holes.

[5] 5. The silicon microphone of claim 3, wherein

The sheet body further has a horizontal extending portion extending outward from the curved portion in the horizontal direction, and the horizontal extending portion is for coupling with the wiring board.

[6] 6. The silicon microphone according to claim 1, wherein

The circuit board is composed of a single-layer substrate on which the first sound hole is opened, and a level of the first sound channel is disposed on the sheet body toward a side of the circuit board Groove.

[7] The silicon microphone according to any one of claims 1 to 6, wherein a third sound hole is provided on the outer casing.

[8] 8. The silicon microphone according to claim 7, wherein

An acoustic damping device is further disposed at the third sound hole provided on the outer casing.

[9] The silicon microphone according to any one of claims 1 to 8, wherein

On the lower surface of the wiring board, a sealing member is disposed around the first sound hole.