CN210491199U

CN210491199U - Intelligent MEMS microphone started when illumination intensity becomes bright

Info

Publication number: CN210491199U
Application number: CN201921798382.1U
Authority: CN
Inventors: 杨国庆; 仪保发; 郭智华
Original assignee: Chaoyang Jushengtai Xinfeng Technology Co Ltd
Current assignee: Chaoyang Jushengtai Xinfeng Technology Co Ltd
Priority date: 2019-10-24
Filing date: 2019-10-24
Publication date: 2020-05-08
Anticipated expiration: 2029-10-24

Abstract

The utility model relates to a microphone field especially relates to an intelligent MEMS microphone that starts when illumination intensity becomes bright, contains packaging substrate and photo resistance, the last Sensor chip that is fixed with of packaging substrate, the Sensor chip passes through the bonding wire and links to each other with ASIC chip electrical property, ASIC links to each other with aforementioned packaging substrate electrical property, photo resistance links to each other with the positive pole of power after establishing ties with a fixed resistance, ASIC chip supply end passes through the triode and is connected with aforementioned photo resistance, be fixed with the cavity board on the packaging substrate, put the photosensitive type base plate that is fixed with aforementioned photo resistance on the cavity board. The function of opening the microphone intelligently according to the illumination intensity can be realized through the device.

Description

Intelligent MEMS microphone started when illumination intensity becomes bright

[ technical field ] A method for producing a semiconductor device

The invention relates to the field of microphones, in particular to an intelligent MEMS microphone which is started when the illumination intensity becomes bright.

[ background of the invention ]

MEMS is a Micro-Electro mechanical System (Micro-Electro mechanical System), which refers to a sensor device with a size of several millimeters or less, and the internal structure of the sensor device is generally in the micrometer or nanometer level, and the sensor device is an independent intelligent System. Briefly, the MEMS is a silicon-based sensor formed by miniaturizing mechanical components of a conventional sensor, fixing a device on a silicon wafer (wafer) by a three-dimensional stacking technique, for example, a three-dimensional through-silicon via (TSV) technique, and finally cutting and assembling the device in a specially-customized packaging form according to different application occasions. The MEMS has the advantages of miniaturization and high integration degree which cannot be achieved by the common sensor;

the existing MEMS microphone enters a working state under the condition of providing proper voltage, the working mode is not intelligent enough, and the MEMS microphone is started intelligently when the illumination intensity becomes bright.

The invention is developed and proposed aiming at the defects of the prior art.

[ summary of the invention ]

It is an object of the present invention to overcome the above-mentioned disadvantages of the prior art and to provide an intelligent MEMS microphone that is activated when the intensity of illumination becomes bright.

The invention can be realized by the following technical scheme:

the invention discloses an intelligent MEMS microphone started when illumination intensity becomes bright, which comprises a packaging substrate and a photoresistor, a Sensor chip is fixed on the packaging substrate and electrically connected with the ASIC chip through a bonding wire, the ASIC is electrically connected with the packaging substrate, the photoresistor is connected with a fixed resistor in series and then is connected with the positive electrode of a power supply, the power supply end of the ASIC chip is connected with the photoresistor through a triode, a cavity plate is fixed on the packaging substrate, a photosensitive substrate fixed with the photoresistor is arranged on the cavity plate, a BIAS end and a VOUT end are arranged on the Sensor chip, the BIAS terminal on the Sensor chip is electrically connected with the BIAS terminal of the ASIC chip, the VOUT end of the Sensor chip is electrically connected with the VOUT end of the ASIC chip, the power supply end of the ASIC chip is connected in parallel with the fixed resistor through the triode and then is connected with one end of the photosensitive resistor in series, and the other end of the photosensitive resistor is grounded. After the ASIC chip is connected with the fixed resistor in parallel, the fixed resistor is connected with the photosensitive resistor in series, when light becomes bright, the resistance value of the photosensitive resistor is reduced, the voltage on the fixed resistor is increased, and when the voltage on the ASIC chip is increased to a certain value, the triode is conducted, so that the ASIC chip is started, and the MEMS microphone starts to work. The MEMS microphone has the working principle that the ASIC chip is powered by an external power supply to enable the ASIC chip to enter a working state, the ASIC chip provides bias voltage for the vibrating diaphragm and the back electrode through a charge pump in the ASIC chip to enable potential difference to exist between the vibrating diaphragm and the back electrode of the Sensor chip, so that under the action of external sound pressure, a sound signal is converted into mechanical energy of the vibrating diaphragm, and meanwhile, the Sensor chip outputs an electric signal from a VOUT end of the Sensor chip under the condition that the distance between the vibrating diaphragm and the back electrode is changed by analogy of the working principle of a parallel plate capacitor, the signal is an initial signal of detected sound, and the signal is processed by the signal ASIC chip and then is output from an OUT end; by utilizing the inner photoelectric effect of the photoresistor with different conductivities under different illumination intensities, current carriers generated by illumination participate in conduction and do drift motion under the action of an external electric field, electrons rush to the anode of a power supply, and holes rush to the cathode of the power supply, so that the resistance value of the photoresistor is rapidly reduced, and the resistance value of the photoresistor is reduced when the photoresistor is irradiated by strong light, thereby playing a role in adjusting the resistance value; the working state of an ASIC chip is controlled in a mode that a photoresistor and a constant value resistor are connected in series for voltage division; after the fixed resistor and the photosensitive resistor are connected in series, the fixed resistor and the photosensitive resistor are connected in parallel with a microphone circuit, and after the ASIC chip is connected in parallel with any resistor, the voltage division value of the ASIC chip can be changed due to the change of the external illumination condition; the divided voltage value becomes small, and the ASIC chip can not work normally.

Preferably, the package substrate is provided with a sound hole.

Preferably, the bonding wire is made of metal materials such as gold, aluminum, copper and the like.

Compared with the prior art, the invention has the following advantages:

the microphone working mode intelligence of this design can select to open or close under the condition that illumination intensity changes, and working mode intelligence, especially some monitor function can select to open automatically daytime or when illumination intensity becomes bright, and other times microphone can get into the sleep mode.

[ description of the drawings ]

The following detailed description of embodiments of the invention is provided in conjunction with the appended drawings, in which:

FIG. 1 is an exploded view of the present invention;

FIG. 2 is a circuit diagram of the present invention;

FIG. 3 is a diagram of a Sensor chip according to the present invention;

FIG. 4 is a diagram of the working state of the Sensor chip;

in the figure: 1. a photoresistor; 2. a cavity plate; 3. an ASIC chip; 4. a Sensor chip; 401. a back electrode; 402. silicon-based; 403. vibrating diaphragm; 5. a package substrate; 51. a sound hole; 6. a triode; 7. a bonding wire; 8. fixing a resistor;

[ detailed description ] embodiments

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings:

as shown in fig. 1 to 4, the invention discloses an intelligent MEMS microphone started when illumination intensity becomes bright, which comprises a package substrate 5 and a photoresistor 1, wherein a Sensor chip 4 is fixed on the package substrate 5, the Sensor chip 4 is electrically connected with an ASIC chip 3 through a bonding wire 7, the ASIC is electrically connected with the package substrate 5, the photoresistor 1 is connected with a fixed resistor 8 in series and then connected with a positive electrode of a power supply, a power supply end of the ASIC chip 3 is connected with the photoresistor 1 through a triode 6, a cavity plate 2 is fixed on the package substrate 5, a photosensitive substrate fixed with the photoresistor 1 is placed on the cavity plate 2, the Sensor chip 4 is provided with a BIAS end and a VOUT end, the BIAS end on the Sensor chip 4 is electrically connected with the BIAS end of the ASIC chip 3, and the VOUT end on the Sensor chip 4 is electrically connected with the VOUT end of the ASIC chip 3. The MEMS microphone has the working principle that the ASIC chip 3 is supplied with power through an external power supply, so that the ASIC chip 3 enters a working state, the ASIC chip 3 provides bias voltage for the vibrating diaphragm 403 and the back electrode 401 through a charge pump in the ASIC to enable potential difference to exist between the vibrating diaphragm 403 and the back electrode 401 of the Sensor chip 4, so that under the action of external sound pressure, a sound signal is converted into mechanical energy of the vibrating diaphragm 403, and meanwhile, by analogy of the working principle of a parallel plate capacitor, under the condition that the distance between the vibrating diaphragm 403 and the back electrode 401 is changed, the Sensor chip 4 outputs an electric signal from a VOUT end of the Sensor chip 4, the signal is an initial signal of detected sound, and the signal is processed by the signal ASIC chip 3 and then is output from an OUT end; by utilizing the internal photoelectric effect of the photosensitive resistor 1 with different conductivities under different illumination intensities, carriers generated by illumination participate in conduction, and do drift motion under the action of an external electric field, electrons rush to the anode of a power supply, and holes rush to the cathode of the power supply, so that the resistance value of the photosensitive resistor 1 is rapidly reduced, and when the photosensitive resistor 1 is irradiated by strong light, the resistance value of the photosensitive resistor 1 is reduced, thereby playing a role in regulating the resistance value; the working state of an ASIC chip 3 is controlled in a mode of serially connecting a photosensitive resistor 1 and a fixed value resistor for voltage division; after the fixed resistor 8 is connected with the photoresistor 1 in series, the fixed resistor is connected with a microphone circuit in parallel, and after the ASIC chip 3 is connected with any resistor in parallel, the voltage division value of the resistor can be changed due to the change of the external illumination condition; the divided voltage value becomes small, the ASIC chip 3 can not obtain a proper voltage after passing through the triode 6, and the ASIC chip 3 can not work normally.

The structure of the Sensor chip 4 is shown in fig. 3, the Sensor chip 4 is composed of a vibrating diaphragm 403, a back electrode 401 and a silicon substrate 402, the vibrating diaphragm 403 and the back electrode 401 are fixed inside a silicon substrate 402 cavity through a semiconductor processing technology (etching, polishing, evaporation and the like), the working principle of the structure can be equivalent to a parallel plate capacitor, the vibrating diaphragm 403 and the back electrode 401 form an upper substrate and a lower substrate of the capacitor, charges directionally move under the action of voltage, a stable voltage difference is formed between the upper substrate and the lower substrate, when external sound pressure acts on the vibrating diaphragm 403, the distance between the vibrating diaphragm 403 and the back electrode 401 changes, the formula C ∈ S/4 π kd shows that the capacitance of the capacitor changes accordingly when the distance changes (C: capacitance ∈: dielectric constant, S: area d between the vibrating diaphragm 403 and the back electrode 401: distance between the two plates, k: Q/C), when the distance changes, the output voltage value changes, Q: constant charge value of the capacitor, Q: constant charge value, Q: constant voltage of the vibrating diaphragm 403, U-3632, and U-U3632, the voltage of the chip can be converted into a voltage after the external sound pressure of the chip is changed, and the sound pressure of the chip is changed into U-1.

Wherein, the package substrate 5 is provided with a sound hole 6.

The bonding wire 7 is made of metal material such as copper.

The power supply end of the ASIC chip 3 is connected in parallel with the fixed resistor 8 through a triode and then is connected with one end of the photosensitive resistor 1 in series, and the other end of the photosensitive resistor 1 is grounded. Through ASIC chip 3 and fixed resistor 8 parallelly connected back and establish ties with photo resistor 1, when light brightened, photo resistor 1 resistance reduces, and voltage increase on the fixed resistor 8 increases to a definite value on the ASIC chip 3, and triode 6 switches on to start ASIC chip 3, the MEMS microphone begins work.

The above description is only a preferred embodiment of the present invention, and it should be noted that a person skilled in the art can make various changes, modifications, substitutions and alterations to the embodiments without departing from the technical principles of the present invention, and such changes, modifications, substitutions and alterations should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides an intelligent MEMS microphone that starts when illumination intensity becomes bright which characterized in that: contain packaging substrate and photo resistance, the last Sensor chip that is fixed with of packaging substrate, the Sensor chip passes through the bonding wire and links to each other with ASIC chip electrical property, ASIC links to each other with aforementioned packaging substrate electrical property, photo resistance links to each other with the positive pole of power after establishing ties with a fixed resistance, ASIC chip supply end establishes ties with aforementioned photo resistance one end after passing through triode and the parallelly connected of fixed resistance, photo resistance other end ground connection, the last cavity board that is fixed with of packaging substrate, put the photosensitive type base plate that is fixed with aforementioned photo resistance on the cavity board.

2. The smart MEMS microphone that is activated when the illumination intensity becomes bright according to claim 1, wherein: and the packaging substrate is provided with a sound hole.

3. The smart MEMS microphone that is activated when the illumination intensity becomes bright according to claim 1, wherein: the bonding wire is made of metal materials such as gold, aluminum and copper.