CN209787439U - Silicon microphone - Google Patents

Abstract

The utility model provides a silicon microphone, its bulge that will have sound picking hole and conduction chamber is as the sound inlet hole, can change the circulation direction of the air current that external sound vibration formed, and can weaken the intensity of air current to avoid the air current of high strength directly to get into in the sound chamber, thereby improved the anti ability of blowing of silicon microphone. In addition, compared with the sound inlet hole with larger size of the existing silicon microphone, the sound pick-up hole of the silicon microphone of the utility model can effectively prevent external tiny foreign matters from entering the silicon microphone; meanwhile, because the side wall of the bulge part of the silicon microphone is provided with the sound pickup hole, the effective aperture ratio of the sound inlet hole is increased; the silicon microphone can effectively prevent external foreign matters from entering the silicon microphone, and the performance of picking up sound of the silicon microphone is improved.

Description

Silicon microphone

Technical Field

The utility model relates to an acoustics and encapsulation field especially relate to a silicon microphone.

Background

The MEMS (Micro-Electro-Mechanical System) technology is a high and new technology developed at a high speed in recent years, and it adopts an advanced semiconductor manufacturing process to implement the batch manufacturing of devices such as sensors and drivers, and compared with the corresponding conventional devices, the MEMS device has very obvious advantages in terms of volume, power consumption, weight and price. Major examples of applications of MEMS devices on the market include pressure sensors, accelerometers, and silicon microphones.

Silicon microphones, also known as MEMS microphones, are microphones fabricated based on MEMS technology. Because of its advantages over ECM in terms of miniaturization, performance, reliability, environmental tolerance, cost and mass production, it rapidly dominates the consumer electronics markets such as cell phones, PDAs, MP3 and hearing aids.

The silicon microphone consists of a MEMS sensor, an ASIC chip, a sound cavity and a circuit board with RF suppression circuitry. The MEMS sensor is a micro capacitor formed by a silicon diaphragm and a silicon back plate, and can convert sound pressure change into capacitance change, and then the capacitance change is reduced by an ASIC chip and is converted into an electric signal, so that the sound-electricity conversion is realized.

The existing silicon microphone has the defects that external airflow directly enters the sound cavity without being blocked, and the sensor is easy to be impacted; and external foreign matters easily enter the silicon microphone from the sound inlet, and the distance between the silicon diaphragm and the silicon back plate is small, so that the silicon microphone is very sensitive to tiny foreign matter particles. This is also a major factor that currently restricts the silicon microphone package and causes the silicon microphone to fail.

At present, the general method for preventing foreign matters from entering into the silicon microphone is as follows:

1. The method has the defects that the foreign matter blocking efficiency is not high only by changing the flow direction of airflow, and the structure causes low aperture ratio of the sound inlet hole, thereby influencing the frequency response characteristic.

2. The method has the defects that although the direct entering of environmental foreign matters can be blocked, the blocked foreign matters are easy to accumulate at the grooves, and a larger hidden trouble exists in the using process.

3. The traditional product with the sound entering from the opening of the shell has poor blocking effect on foreign matters because the diameter of the opening is within about 800 mu m in consideration of the hidden troubles of the foreign matters and the anti-blowing capability.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a silicon microphone is provided, it can be effectively blockking that external foreign matter gets into under the inside prerequisite of silicon microphone, improves the performance of silicon microphone.

In order to solve the problem, the utility model provides a silicon microphone, it includes a component and a sensor, the component with the sensor forms a sound chamber, the outer wall of component has an orientation the outside outstanding bulge of component, the bulge has a conduction chamber and a plurality of sound holes of picking up, the conduction chamber with sound chamber intercommunication, it sets up to pick up the sound hole the lateral wall of bulge and with conduction chamber intercommunication, external air current warp get into behind the pickup hole conversion circulation direction the conduction chamber, and the warp the conduction chamber gets into the sound chamber.

In one embodiment, a portion of the outer wall of the member extends toward the exterior of the member to form the projection.

In one embodiment, the protrusion is formed by stamping or machining the outer wall of the member.

In one embodiment, the member is integrally formed with the projection.

In one embodiment, the side walls of the projections have the same thickness as the outer wall of the member.

In one embodiment, the projection is formed above the sound cavity.

In one embodiment, the pick-up hole has a width of less than 50 microns.

In one embodiment, the sound pickup holes are arranged at equal intervals along the circumferential direction of the protruding part.

In one embodiment, the axis of the sound pickup hole is perpendicular to the axis of the conduction cavity.

In one embodiment, the member is a housing of the silicon microphone.

The utility model discloses silicon microphone will have the bulge of picking up sound hole and conduction chamber as the sound inlet, can change the circulation direction of the air current that external sound vibration formed, and can weaken the intensity of air current to avoid the air current of high strength directly to get into in the sound chamber, thereby improved the anti ability of blowing of silicon microphone.

In addition, compared with the sound inlet hole with larger size of the existing silicon microphone, the sound pick-up hole of the silicon microphone of the utility model can effectively prevent external tiny foreign matters from entering the silicon microphone; meanwhile, because the side wall of the bulge part of the silicon microphone is provided with the sound pickup hole, the effective aperture ratio of the sound inlet hole is increased; the silicon microphone can effectively prevent external foreign matters from entering the silicon microphone, and the performance of picking up sound of the silicon microphone is improved.

drawings

Fig. 1 is a schematic external structural view of a silicon microphone according to an embodiment of the present invention;

FIG. 2 is a schematic sectional view taken along the line A-A in FIG. 1;

Fig. 3 is an enlarged schematic view of the position of the projection in fig. 2.

Detailed Description

The following describes in detail a silicon microphone according to the present invention with reference to the accompanying drawings.

Fig. 1 is a schematic external structural view of a silicon microphone according to an embodiment of the present invention, and fig. 2 is a schematic sectional view taken along a direction a-a in fig. 1.

Referring to fig. 1 and 2, the silicon microphone of the present invention includes a member 10 and a sensor 11, wherein the member 10 and the sensor 11 form an acoustic cavity. In this embodiment, the member 10 is a housing of the silicon microphone, and in other embodiments of the present invention, the member 10 may also be other structures of the silicon microphone as long as the technical problem of the present invention can be solved.

Specifically, in this embodiment, the silicon microphone further includes a circuit board 12 and an ASIC chip 13. The sensor 11 is disposed on the circuit board 12, and a first sound cavity 14 is formed between the sensor 11 and the circuit board 12. The ASIC chip 13 is disposed on the circuit board 12. The ASIC chip 13 is electrically connected to the circuit board 12 and the sensor 11 to perform transmission of an acoustic-electric signal. The member 10, i.e. the housing of the silicon microphone, covers the circuit board 12 and forms a receiving cavity between the circuit board 12 and the member 10. The sensor 11 and the ASIC chip 13 are located in the accommodating cavity, and a second sound cavity 15 is formed between the sensor 11 and the component 10. Wherein, the base material of the circuit board 12 includes but is not limited to FR4, ceramic substrate, and the base material of the component 10 includes but is not limited to metal, polymer, FR4 material. The circuit board 12, the sensor 11, the ASIC chip 13 and the component 10 are all conventional structures in the art, and the sound conversion principle of a silicon microphone is also well known by those skilled in the art and will not be described again.

With continued reference to fig. 1 and 2, the outer wall of the member 10 has a protrusion 16 protruding toward the outside of the member 10. In the drawings, the size of the protruding portion 16 is exaggerated for clarity of explanation of the technical solution of the silicon microphone of the present invention. Specifically, in the present embodiment, a part of the outer wall of the member 10 extends toward the outside of the member 10 to form the projection 16. For example, the protrusion 16 may be formed by punching the outer wall of the member 10 such that a portion of the outer wall of the member 10 extends toward the outside of the member 10. Wherein the side walls of the projections 16 have the same thickness as the outer wall of the member 10. Of course, the present invention is not limited to forming the protrusion 16 by stamping, and other methods known to those skilled in the art, such as casting or machining, may be used to form the protrusion 16 in other embodiments of the present invention. Preferably, in an embodiment of the present invention, the protrusion 16 is integrally formed with the member 10.

The protruding portion 16 has a conductive cavity 161 and a plurality of sound pickup holes 162.

The conducting cavity 161 communicates with the second sound cavity 15. Specifically, in the present embodiment, the protrusion 16 is formed by punching the outer wall of the member 10, and the side of the protrusion 16 facing the second sound chamber 15 forms the transmission chamber 161.

The sound pickup hole 162 is provided in a side wall of the boss 16 and communicates with the conductive chamber 161. Specifically, the sound pickup hole 162 penetrates through a side wall of the protruding portion 16 to communicate with the conductive chamber 161. Wherein the sound pickup hole 162 may be formed by punching a side wall of the protrusion 16. In other embodiments of the present invention, the sound pickup hole 162 may be formed by other methods known to those skilled in the art. The number of the pickup holes 162 can be set according to actual requirements.

In the silicon microphone of the present invention, the projection 16 serves as a sound inlet of the silicon microphone. The air flow formed by the external sound vibration enters the second sound cavity 15 through the sound pickup hole 162 and the conduction cavity 161. The air flow changes the flow direction after passing through the sound pickup hole 162, so that the high-intensity air flow is prevented from directly entering the second sound cavity 15, and the blowing resistance of the silicon microphone is improved.

Fig. 3 is an enlarged schematic view of the position of the projection 16 in fig. 2, and the flow direction of the air flow is schematically shown by an arrow in fig. 3. Referring to fig. 3, the airflow generated by the external sound vibration changes the flowing direction after passing through the sound pickup hole 162, enters the conductive cavity 161, and enters the second sound cavity 15 through the conductive cavity 161. Wherein the sound pickup hole 162 is used for changing the flowing direction of the air flow. Specifically, the vertical air flow generated by the external sound vibration forms a transverse air flow after passing through the sound pickup hole 162, and the transverse air flow enters the conductive cavity 161 and is redirected again by the conductive cavity 161, for example, the transverse air flow is changed into the vertical air flow and enters the second sound cavity 15.

The utility model discloses silicon microphone will have sound picking hole 162 and conduct the bulge 16 of chamber 161 as the sound inlet hole, can change the circulation direction of the air current that external sound vibration formed, and can weaken the intensity of air current to avoid the air current of high strength directly to get into in the second sound chamber 15, thereby improved the anti ability of blowing of silicon microphone.

In addition, compared with the sound inlet hole with larger size of the existing silicon microphone, the sound pick-up hole 162 of the silicon microphone of the present invention can effectively prevent external tiny foreign matters from entering the silicon microphone; and simultaneously, because the utility model discloses silicon microphone sets up on the lateral wall of bulge 16 and picks up sound hole 162, has increased the effective aperture ratio in sound inlet hole to can effectively block under the prerequisite of external foreign matter, improve the performance that silicon microphone picked up sound.

preferably, in this embodiment, the axis of the sound pickup hole 162 is perpendicular to the axis of the conductive cavity 161, so as to further change the flowing direction of the air flow formed by the external sound vibration and weaken the intensity of the air flow. In other embodiments of the present invention, the axis of the sound pickup hole 162 and the axis of the conduction cavity 161 may also be an acute angle.

Preferably, the protrusion 16 is formed above the second sound cavity 15 to improve the sound collection capability of the protrusion 16, and thus the performance of the silicon microphone.

Preferably, in the present embodiment, the width of the sound pickup hole 162 is less than 50 μm. Compared with the larger sound inlet hole in the prior art, the protruding part 16 can effectively prevent external foreign matters from entering the silicon microphone through the sound pickup hole 162, and the performance of the silicon microphone is further improved. Of course, in other embodiments of the present invention, the width of the sound pickup hole 162 may also be set according to actual requirements, and the present invention is not limited thereto.

Preferably, the sound pickup holes 162 are arranged at equal intervals along the circumferential direction of the protruding portion 16. Specifically, the distances between the adjacent sound pickup holes 162 are equal along the circumferential direction of the protruding portion 16, so that the silicon microphone can uniformly pick up sound, providing the performance of the silicon microphone.

preferably, in the present embodiment, it is sufficient that the height of the protruding portion 16 is greater than the height of the sound pickup hole 162, that is, the sound pickup hole 162 can be formed in the side wall of the protruding portion 16. The protrusion 16 slightly protrudes from the component 10, so that the protrusion 16 has little influence on the second cavity 15, and thus the bandwidth of the second cavity 15 is not affected. Of course, in other embodiments of the present invention, the height of the protruding portion 16 may also be set according to actual requirements, and the present invention is not limited thereto.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims (10)

1. A silicon microphone comprises a component and a sensor, wherein the component and the sensor form a sound cavity, the silicon microphone is characterized in that a protruding part protruding towards the outside of the component is arranged on the outer wall of the component, the protruding part is provided with a conducting cavity and a plurality of sound picking holes, the conducting cavity is communicated with the sound cavity, the sound picking holes are arranged on the side wall of the protruding part and are communicated with the conducting cavity, and outside air flow enters the conducting cavity after the circulation direction of the outside air flow is changed through the sound picking holes and enters the sound cavity through the conducting cavity.

2. A silicon microphone as claimed in claim 1 wherein a portion of the outer wall of the member extends outwardly of the member to form the projection.

3. A silicon microphone as claimed in claim 1 wherein the projections are formed by stamping or machining of the outer walls of the members.

4. A silicon microphone as claimed in claim 1 wherein the member is integrally formed with the boss.

5. A silicon microphone as claimed in claim 1 wherein the side walls of the projections are of the same thickness as the outer walls of the members.

6. A silicon microphone as claimed in claim 1 wherein the boss is formed above the acoustic cavity.

7. A silicon microphone as claimed in claim 1 wherein the pick-up hole is less than 50 microns wide.

8. A silicon microphone as claimed in claim 1 wherein the pick-up holes are equally spaced around the circumference of the boss.

9. A silicon microphone as claimed in claim 1 wherein the centre of the pick-up hole is perpendicular to the centre of the conductive cavity.

10. A silicon microphone as claimed in claim 1 wherein the member is a housing of the silicon microphone.