TWI547180B - Microphone device - Google Patents

Description

Microphone device

The present invention relates to a microphone device, and more particularly to an integrated micro electro mechanical systems (MEMS) microphone device.

Micro electro mechanical systems (MEMS) are integrated into a micro component or device through a semiconductor process through a combination of electronic, electrical, and mechanical functions. The MEMS microphone has dimensions compared to a microphone that uses a conventional assembly method. Small, low power consumption and the advantage of better suppression of environmental disturbances (such as temperature changes, vibration, electromagnetic interference, etc.).

Please refer to FIG. 1 , which is a schematic diagram of a conventional capacitive MEMS microphone 100 . As shown in FIG. 1, the conventional MEMS condenser microphone 100 includes a substrate 20, a cymbal substrate 30, a diaphragm 40, a backplane 50, and a specific application integrated circuit (Application-Specific IC, The ASIC 60, wherein the germanium substrate 30, the diaphragm 40, the backplate 50, and the application-specific integrated circuit 60 constitute a micro electro mechanical systems (MEMS). The diaphragm 40 is an elastic film which generates vibration when subjected to sound pressure, thereby causing a micro-distance change, resulting in dynamic micro-displacement between the diaphragm 40 and the backing plate 50, thereby making the capacitance value of the microelectromechanical condenser microphone 100 Change with it. The 矽 substrate 30 is disposed on the substrate 20 in the same manner as the specific application integrated circuit 60, and the specific application integrated circuit 60 is used to provide a stable bias voltage required for the normal operation of the MEMS, and the signal is amplified and output. .

However, some of the noise may be coupled to the MEMS via the application specific integrated circuit 60, thereby causing severe disruption of the MEMS condenser microphone 100, resulting in reduced performance. Therefore, there is a need to provide a new condenser microphone to improve the above problems.

In view of the above, it is an object of the present invention to provide a condenser microphone having conductive cover and/or differential signal transmission for eliminating the above-mentioned problems caused by noise coupling effects.

An embodiment of the present invention provides a microphone device including a substrate, a MEMS unit, an integrated circuit, and an upper cover. The MEMS unit includes a substrate, a cover, and a condenser microphone. The cover is disposed on the substrate, wherein the cover is made of a conductive material. The condenser microphone is disposed between the cover and the substrate, wherein the condenser microphone forms a resonant cavity with the cover. The integrated circuit is disposed on the substrate for controlling the condenser microphone. The upper cover is connected to the substrate, wherein the MEMS unit and the integrated circuit are located in an accommodating space formed by the substrate and the upper cover.

Embodiments of the present invention use conductive covering, transmission through a differential interface to realize transmission between an integrated circuit and a condenser microphone, or a plurality of integration methods between an integrated circuit and a condenser microphone to greatly reduce noise coupling. The effect, which in turn improves the performance of the condenser microphone.

100‧‧‧Capacitive MEMS microphone

20‧‧‧Substrate

30‧‧‧矽Base

40‧‧‧Densor

50‧‧‧ Backplane

60‧‧‧Special application integrated circuits

200, 400, 500, 600‧‧‧ microphone devices

210, 610‧‧‧ substrate

211‧‧‧ accommodating space

220, 420‧‧‧Micro-Electromechanical System Unit

230, 430, 530‧‧ ‧ integrated circuits

240, 640‧‧‧ Cover

223, 423‧‧‧ base

224‧‧‧ Cover

250‧‧‧ condenser microphone

242, 246, 642‧‧‧ openings

270‧‧‧Differential interface

300‧‧‧Differential architecture

251, 252‧‧‧ capacitor

231, 232‧‧‧ endpoint

280‧‧‧Differential Amplifier

Figure 1 is a schematic diagram of a conventional microelectromechanical condenser microphone.

Fig. 2 is a schematic view of a microphone device according to a first embodiment of the present invention.

Fig. 3 is a schematic view showing a differential structure of the microphone device shown in Fig. 2.

Fig. 4 is a schematic view of a microphone device according to a second embodiment of the present invention.

Fig. 5 is a schematic view of a microphone device according to a third embodiment of the present invention.

Figure 6 is a schematic diagram of a microphone device in accordance with a fourth embodiment of the present invention.

Certain terms are used in the specification and subsequent patent applications to refer to specific Components. It should be understood by those of ordinary skill in the art that hardware manufacturers may refer to the same elements by different nouns. The scope of this specification and the subsequent patent application do not use the difference of the names as the means for distinguishing the elements, but the difference in function of the elements as the criterion for distinguishing. The term "including" as used throughout the specification and subsequent claims is an open term and should be interpreted as "including but not limited to". In addition, the term "coupled" is used herein to include any direct and indirect electrical connection. Therefore, if a first device is coupled to a second device, it means that the first device can be directly electrically connected to the second device or indirectly electrically connected to the second device through other devices or connection means.

Please refer to FIG. 2, which is a schematic diagram of a microphone device 200 according to a first embodiment of the present invention. The microphone device 200 includes, but is not limited to, a carrier board 210, a MEMS unit 220, an integrated circuit 230, and an upper cover 240. The substrate 210 can be, for example, a printed circuit board (PCB), but is not limited thereto. The MEMS unit 220 includes, but is not limited to, a substrate 223, a cap 224, and a condenser microphone 250, which may be, for example, a sputum substrate. The cover 224 is disposed on the base 223 and is made of a conductive material, and the cover 224 has an opening 246. For the condenser microphone 250, the cover 224 in this embodiment can provide dustproof and electromagnetic protection (electromeganietc shielding). . The condenser microphone 250 is disposed between the cover 224 and the substrate 223, wherein the condenser microphone 250 and the cover 224 form a resonant cavity. The integrated circuit 230 is disposed on the substrate 210 for controlling the operation of the condenser microphone 250. The upper cover 240 is connected to the substrate 210, and the connection is airtight. The MEMS unit 220 and the integrated circuit 230 are located in the accommodating space 211 formed by the substrate 210 and the upper cover 240. The upper cover 240 may be made of a conductive material. However, it is not limited to this, and PCB material can also be used. In addition, the upper cover 240 has an opening 242, and the opening 242 can be disposed not to the opening 246 of the cover 224 as shown in FIG. 2 to reduce the probability of dust falling into the condenser microphone 250 to achieve dustproof effect. However, the invention is not limited thereto.

In the present embodiment, the substrate 223 of the MEMS unit 220 is disposed on the substrate 210, and the integrated circuit 230 is electrically connected to the condenser microphone 250 through a differential interface 270. Please refer to FIG. 3, which is a schematic diagram of the differential structure 300 of the microphone device 200 shown in FIG. 2. As shown in FIG. 3, the differential interface 270 is a two-capacitor 251 of a condenser microphone. 252 and 252 are respectively coupled to the two end points 231 and 232 of the integrated circuit 230. Due to the differential setting, the noises outputted by the two end points 231 and 232 are reversed, so that they are offset each other, thereby greatly reducing The external interference with the condenser microphone 250 enhances the performance of the microphone device 200. Capacitors 251, 252 are coupled to a differential amplifier 280 in condenser microphone 250, and differential amplifier 280 receives the differential input and produces a single-ended output. In addition, the differential interface 270 shown in FIG. 3 is only an example of the present invention, and it is within the scope of the present invention to achieve transmission between the integrated circuit and the condenser microphone by any differential means.

Please refer to FIG. 4, which is a schematic diagram of a microphone device 400 according to a second embodiment of the present invention. The second embodiment differs from the first embodiment in that the second embodiment integrates the integrated circuit 430. In the base 423 of the MEMS unit 420. Based on the integrated architecture described above, the integrated circuit 430 does not need to transmit a signal to the condenser microphone 250 through a transmission interface (such as the differential interface 270 described above), so that no noise is coupled to the condenser microphone 250. Similarly, the microphone device 400 can greatly reduce the interference of noise compared to the prior art, so that it has better performance. For the sake of brevity, the rest of the components similar to the microphone device 200 will not be described again.

Please refer to FIG. 5, which is a schematic diagram of a microphone device 500 according to a third embodiment of the present invention. The third embodiment differs from the first embodiment in that, in the third embodiment, The electromechanical system unit 220 is stacked on the integrated circuit 530, that is, the integrated circuit 530 is disposed between the substrate 210 and the MEMS unit 220. Similarly, since the integrated circuit 530 and the MEMS unit 220 form an integrated architecture, the integrated circuit 530 does not need to transmit a signal to the condenser microphone 250 through a transmission interface (such as the aforementioned differential interface 270). Therefore, no noise is coupled to the condenser microphone 250. Therefore, compared with the prior art, the microphone device 500 can greatly reduce the interference of noise, so that it has better performance. For the sake of brevity, the rest of the components similar to the microphone device 200 will not be described again.

The present invention is not limited to the integrated manner between the integrated circuit and the condenser microphone provided by the second embodiment and the third embodiment, and in other variations of the present invention, the integrated circuit and the condenser microphone may also be used. Different integration methods reduce the noise coupled to the condenser microphone.

Please refer to FIG. 6. FIG. 6 is a schematic diagram of a microphone device 600 according to a fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment in that, in the fourth embodiment, the microphone device 600 is The substrate 610 is provided with an opening 642. The base 223 of the MEMS unit 220 is disposed on the substrate 610, and the condenser microphone 250 is opposite to the opening 642 of the substrate 610, and the upper cover 640 has no opening. With this arrangement, since dust does not fall from the upper cover 640 into the microphone device 600, the microphone device 600 can have a better dustproof effect. In addition, the transmission interface 270 can also use the aforementioned differential interface to further reduce noise. For the sake of brevity, the rest of the components similar to the microphone device 200 will not be described again.

In summary, the embodiment of the present invention realizes the transmission between the integrated circuit and the condenser microphone through the differential interface, or through various integration methods between the integrated circuit and the condenser microphone, thereby greatly reducing the miscellaneous The coupling effect is used to improve the performance of the condenser microphone.

The above description is only a preferred embodiment of the present invention, and the scope of the patent application according to the present invention is Equal variations and modifications are intended to be within the scope of the present invention.

200‧‧‧Microphone device

210‧‧‧Substrate

220‧‧‧Micro-Electromechanical System Unit

230‧‧‧ integrated circuit

240‧‧‧Top cover

223‧‧‧Base

224‧‧‧ Cover

250‧‧‧ condenser microphone

242, 246‧‧‧ openings

270‧‧‧Differential interface

Claims (10)

A microphone device comprising: a substrate; a micro electro mechanical systems (MEMS) unit, comprising: a substrate; a cover disposed on the substrate, wherein the cover is made of a conductive material; and a capacitor a microphone disposed between the cover and the substrate, wherein the condenser microphone forms a resonant cavity with the cover; an integrated circuit is disposed on the substrate for controlling the condenser microphone; and an upper cover and a connection In the substrate, the MEMS unit and the integrated circuit are located in an accommodating space formed by the substrate and the upper cover. The microphone device of claim 1, wherein the cover has an opening. The microphone device of claim 2, wherein the upper cover has an opening, and the opening of the upper cover is not for the opening of the cover. The fourth embodiment is the microphone device of claim 1, wherein the substrate has an opening, the substrate of the MEMS unit is disposed on the substrate, and the condenser microphone is directly opposite to the substrate The opening. The first embodiment is the microphone device of claim 1, wherein the substrate of the MEMS unit is disposed on the substrate, and the integrated circuit is electrically connected to the condenser microphone through a differential interface . The second embodiment is the microphone device of claim 1, wherein the integrated circuit is formed in the substrate of the MEMS unit. (Third Embodiment) The microphone device of claim 1, wherein the MEMS unit is stacked on the integrated circuit. The microphone device of claim 1, wherein the upper cover is made of a conductive material. The microphone device of claim 1, wherein the substrate is a printed circuit board (PCB). The microphone device of claim 1, wherein the connection between the upper cover and the substrate is airtight.