CN209845303U - Novel sound packaging structure advances at bottom of microacoustic chip - Google Patents

Abstract

The utility model discloses a novel sound packaging structure is advanced at bottom of microacoustic chip, including PCB packaging substrate, PCB packaging substrate's top is provided with metal casing, PCB packaging substrate's top and the inside that is located metal casing are provided with into the sound hole, PCB packaging substrate's top and the both sides that are located into the sound hole are provided with ASIC chip and MEMS chip respectively, and the ASIC chip outside covers there is the flexible glue protective layer, all be connected through the bonding gold wire between ASIC chip and the MEMS chip and between ASIC chip and the PCB packaging substrate respectively, just be located into the sound hole between PCB packaging substrate and the inside top of metal casing and keep away from one side of MEMS chip and be provided with the arc guide plate, the inside top edges and corners department of metal casing and concave surface one side that is located the arc guide plate are provided with the. The beneficial effects are that: strong anti-interference capability, high reliability and small product volume.

Description

Novel sound packaging structure advances at bottom of microacoustic chip

Technical Field

The utility model relates to a micro-electromechanical technology field particularly, relates to a novel sound packaging structure is advanced at bottom of microacoustic chip.

Background

Micro-electro-mechanical system (MEMS) microphones, or silicon microphones, are widely used for sound collection of flat panel electronic devices due to their advantages of small size and suitability for surface mounting. The silicon microphone is typically electrically connected to an integrated circuit chip that provides the bias voltages required for proper operation of the silicon microphone and receives and processes the electrical signals output by the silicon microphone after acoustic-to-electrical conversion.

With the progress of high technology, smart phones, unmanned planes, anti-theft monitoring, computer computers, bluetooth headsets, wearable products, smart home sound control products, and the like are being updated. The requirements of sound control electronic products are higher and higher, the appearance volume is smaller and smaller, the internal assembly space of a host is continuously reduced, and the miniaturization of the structures of internal and external devices of the sound control products is required. At present, the existing silicon microphone usually adopts an upper-voice-in mode to receive external voice signals, which is not beneficial to the miniaturization production of the silicon microphone and further influences the miniaturization of electronic equipment.

An effective solution to the problems in the related art has not been proposed yet.

SUMMERY OF THE UTILITY MODEL

To the problem in the correlation technique, the utility model provides a sound packaging structure is advanced at bottom of novel little acoustics chip to overcome the above-mentioned technical problem that current correlation technique exists.

Therefore, the utility model discloses a specific technical scheme as follows:

a novel bottom sound-feeding packaging structure of micro-acoustic chip comprises a PCB (printed circuit board) packaging substrate, the top end of the PCB packaging substrate is provided with a metal shell, the top end of the PCB packaging substrate and the metal shell are internally provided with sound inlet holes, an ASIC (integrated circuit) chip and an MEMS (micro electro mechanical system) chip are respectively arranged at the top end of the PCB packaging substrate and at the two sides of the sound inlet hole, and the outer side of the ASIC chip is covered with a soft rubber protective layer, the ASIC chip and the MEMS chip and the ASIC chip and the PCB packaging substrate are respectively connected through bonding gold wires, an arc-shaped guide plate is arranged between the PCB packaging substrate and the top end inside the metal shell and on one side of the sound inlet hole far away from the MEMS chip, the metal casing is inside top edges and corners department and is located concave surface one side of arc guide plate is provided with the reflecting plate.

Further, in order to ensure the absorption of the microacoustic chip on sound and further improve the sound-electricity conversion effect of the microacoustic chip, the PCB package substrate is provided with a positive interface VDD, a negative interface GND and an output interface OUT, the ASIC chip is provided with a first port, a second port, a third port, a fourth port, a fifth port and a sixth port, and the MEMS chip is provided with a BIAS interface BIAS and a communication interface SIGNAL;

the positive interface VDD is connected to the sixth port, the negative interface GND is connected to the second port, and the output interface OUT is connected to the first port; the BIAS interface BIAS is connected to the fifth port, and the communication interface SIGNAL is connected to the fourth port.

Furthermore, in order to ensure the micro-acoustic chip to absorb sound and further improve the sound-electricity conversion effect of the micro-acoustic chip, the MEMS chip includes a set of substrates symmetrically disposed on the top of the PCB packaging substrate, a vibrating diaphragm is disposed on the top of the substrates, a back electrode is disposed on the top of the vibrating diaphragm, a cavity is formed between the set of substrates and the vibrating diaphragm, and an air vent is disposed in the middle of the vibrating diaphragm.

Furthermore, in order to prevent the sound waves entering the cavity from reflecting, the influence of the reflected sound waves on the vibrating diaphragm in the cavity is eliminated, and the sensitivity and the signal-to-noise ratio of the micro-acoustic chip are improved, and the bottom end of the cavity is provided with a sound absorption film.

Furthermore, in order to prevent the sound waves entering the cavity from reflecting, so that the influence of the reflected sound waves in the cavity on the diaphragm is eliminated, and the sensitivity and the signal-to-noise ratio of the micro-acoustic chip are improved, the sound absorption film is made of polyimide materials.

The utility model has the advantages that:

(1) the sound inlet hole is formed in the PCB packaging substrate, so that the micro-acoustic chip is changed from the traditional upper sound inlet mode into the lower sound inlet mode, the micro-acoustic chip has the advantages of being high in anti-interference capacity, high in reliability and small in product size, good in effect, and meanwhile cost is greatly saved, and miniaturization of electronic equipment is facilitated.

(2) Through setting up arc guide plate and reflecting plate to along the direction propagation of arc guide plate when making sound get into metal casing inside from advancing the sound hole, reflect to the MEMS chip through the reflecting plate simultaneously, thereby slow down the loss of sound, improve the absorptivity of MEMS chip to sound, and then improve the sound-electricity conversion effect of little acoustics chip.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a novel microacoustic chip bottom sound-entering packaging structure according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a PCB package substrate of a novel microacoustic chip bottom sound-feeding package structure according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a MEMS chip of a novel microacoustic chip bottom sound-feeding packaging structure according to an embodiment of the present invention.

In the figure:

1. a PCB package substrate; 2. a metal housing; 3. a sound inlet hole; 4. an ASIC chip; 5. an MEMS chip; 501. a substrate; 502. vibrating diaphragm; 503. a back electrode; 504. a chamber; 505. an air vent; 506. a sound absorbing film; 6. a soft rubber protective layer; 7. a bonding alloy wire; 8. an arc-shaped guide plate; 9. a reflective plate.

Detailed Description

For further explanation of the embodiments, the drawings are provided as part of the disclosure and serve primarily to illustrate the embodiments and, together with the description, to explain the principles of operation of the embodiments, and to provide further explanation of the invention and advantages thereof, it will be understood by those skilled in the art that various other embodiments and advantages of the invention are possible, and that elements in the drawings are not to scale and that like reference numerals are generally used to designate like elements.

According to the utility model discloses an embodiment provides a sound packaging structure is advanced at bottom of novel little acoustics chip.

Referring now to the drawings and the detailed description, as shown in fig. 1-3, a novel micro-acoustic chip bottom sound-entering package structure according to an embodiment of the present invention includes a PCB package substrate 1, a metal housing 2 is disposed on a top end of the PCB package substrate 1, a sound-entering hole 3 is disposed on a top end of the PCB package substrate 1 and inside the metal housing 2, an ASIC chip 4 and an MEMS chip 5 are respectively disposed on a top end of the PCB package substrate 1 and on both sides of the sound-entering hole 3, and a soft rubber protective layer 6 covers an outer side of the ASIC chip 4, an arc-shaped guide plate 8 is disposed between the ASIC chip 4 and the MEMS chip 5 and between the ASIC chip 4 and the PCB package substrate 1 respectively through a bonding alloy wire 7, and an arc-shaped guide plate 8 is disposed between the PCB package substrate 1 and the top end inside the metal housing 2 and on a side of the sound-entering hole 3 away from the MEMS chip 5, the top edge of the metal shell 2 is provided with a reflecting plate 9 on one side of the concave surface of the arc-shaped guide plate 8.

By means of the technical scheme, the sound inlet hole 3 is formed in the PCB packaging substrate 1, so that the micro-acoustic chip is changed from a traditional upper sound inlet mode to a lower sound inlet mode, and the micro-acoustic chip has the advantages of being high in anti-interference capacity, high in reliability, small in product size and good in effect, greatly saves cost, and is beneficial to miniaturization of electronic equipment; through setting up arc guide plate 8 and reflecting plate 9 to along the direction propagation of arc guide plate 8 when making sound get into metal casing 2 inside from advancing sound hole 3, reflect to MEMS chip 5 through reflecting plate 9 simultaneously, thereby slow down the loss of sound, improve MEMS chip 5 to the absorptivity of sound, and then improve the sound-electricity conversion effect of little acoustics chip.

In one embodiment, for the PCB package substrate 1, a positive interface VDD, a negative interface GND and an output interface OUT are disposed on the PCB package substrate 1, a first port, a second port, a third port, a fourth port, a fifth port and a sixth port are disposed on the ASIC chip 4, and a BIAS interface BIAS and a communication interface SIGNAL are disposed on the MEMS chip 5; the positive interface VDD is connected to the sixth port, the negative interface GND is connected to the second port, and the output interface OUT is connected to the first port; the BIAS interface BIAS is connected with the fifth port, and the communication interface SIGNAL is connected with the fourth port, so that the sound absorption of the micro-acoustic chip is ensured, and the sound-electricity conversion effect of the micro-acoustic chip is improved.

In an embodiment, for the MEMS chip 5, the MEMS chip 5 includes a set of substrates 501 symmetrically disposed on the top of the PCB package substrate 1, a diaphragm 502 is disposed on the top of the substrate 501, a back electrode 503 is disposed on the top of the diaphragm 502, a cavity 504 is formed between the set of substrates 501 and the diaphragm 502, and an air vent 505 is disposed in the middle of the diaphragm 502, so as to ensure the micro-acoustic chip to absorb sound, and further improve the sound-electricity conversion effect of the micro-acoustic chip.

In one embodiment, for the cavity 504, the bottom end of the cavity 504 is provided with a sound absorption film 506, so that the sound waves entering the cavity 504 are not reflected any more, thereby eliminating the influence of the reflected sound waves in the cavity 504 on the diaphragm 502, and further improving the sensitivity and the signal-to-noise ratio of the micro-acoustic chip.

In one embodiment, for the sound-absorbing film 506, the sound-absorbing film 506 is made of polyimide, so that the sound waves entering the cavity 504 are not reflected, the influence of the reflected sound waves in the cavity 504 on the diaphragm 502 is eliminated, and the sensitivity and the signal-to-noise ratio of the micro-acoustic chip are improved.

The working principle is as follows: when the novel micro-acoustic chip bottom sound inlet packaging structure is applied specifically, the MEMS chip 5 and the ASIC chip 4 are respectively fixed on a chip mounting area of the PCB packaging substrate 1 by using special high-soft silver paste and then integrated in a package, and different chips can be manufactured by using different materials and process technologies; the bonding alloy wire 7 is welded on the electrode of the ASIC chip 4 and communicated with the circuit of the PCB packaging substrate 1, and the soft glue protective layer 6 protects the bonding welding point on the circuit of the ASIC chip 4 and the PCB packaging substrate 1; the lead-free metal shell 2 enables the SMT to be fixed on the PCB packaging substrate 1 through solder paste in a reflow soldering mode to protect the ASIC chip 4, the MEMS chip 5 and the bonding gold wire 7, and therefore the sensitivity of the sound transmitted by the micro-acoustic chip to sound wave signals is enhanced.

In summary, with the aid of the technical solution of the present invention, the sound inlet hole 3 is disposed on the PCB package substrate 1, so that the micro-acoustic chip is changed from the traditional upper sound inlet mode to the lower sound inlet mode, and the micro-acoustic chip has the advantages of strong anti-interference capability, high reliability, small product volume, and good effect, thereby greatly saving cost and being beneficial to miniaturization of electronic equipment; through setting up arc guide plate 8 and reflecting plate 9 to along the direction propagation of arc guide plate 8 when making sound get into metal casing 2 inside from advancing sound hole 3, reflect to MEMS chip 5 through reflecting plate 9 simultaneously, thereby slow down the loss of sound, improve MEMS chip 5 to the absorptivity of sound, and then improve the sound-electricity conversion effect of little acoustics chip.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "disposed," "connected," "fixed," "screwed" and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through an intermediate medium, and may be connected through the inside of two elements or in an interaction relationship between two elements, unless otherwise specifically defined, and the specific meaning of the above terms in the present invention will be understood by those skilled in the art according to specific situations.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (5)

1. A novel micro-acoustic chip bottom sound inlet packaging structure is characterized by comprising a PCB packaging substrate (1), wherein a metal shell (2) is arranged at the top end of the PCB packaging substrate (1), a sound inlet hole (3) is formed in the top end of the PCB packaging substrate (1) and positioned in the metal shell (2), an ASIC chip (4) and an MEMS chip (5) are respectively arranged at the top end of the PCB packaging substrate (1) and positioned at two sides of the sound inlet hole (3), a soft rubber protective layer (6) covers the outer side of the ASIC chip (4), an arc-shaped guide plate (8) is respectively arranged between the ASIC chip (4) and the MEMS chip (5) and between the ASIC chip (4) and the PCB packaging substrate (1) and is connected through a bonding alloy wire (7), and an arc-shaped guide plate (8) is arranged between the PCB packaging substrate (1) and the top end in the metal shell (2) and positioned at one side of the sound inlet hole (3) far away from the MEMS chip (5), the metal shell (2) is internally provided with a reflecting plate (9) at the edge of the top and positioned on one side of the concave surface of the arc-shaped guide plate (8).

2. The novel microacoustic chip bottom-entry package structure according to claim 1, wherein a positive interface VDD, a negative interface GND and an output interface OUT are disposed on the PCB package substrate (1), a first port, a second port, a third port, a fourth port, a fifth port and a sixth port are disposed on the ASIC chip (4), a BIAS interface BIAS and a communication interface SIGNAL are disposed on the MEMS chip (5);

the positive interface VDD is connected to the sixth port, the negative interface GND is connected to the second port, and the output interface OUT is connected to the first port; the BIAS interface BIAS is connected to the fifth port, and the communication interface SIGNAL is connected to the fourth port.

3. The novel micro-acoustic chip substrate sound-entering packaging structure is characterized in that the MEMS chip (5) comprises a group of substrates (501) symmetrically arranged at the top end of the PCB packaging substrate (1), a vibrating diaphragm (502) is arranged at the top end of each substrate (501), a back electrode (503) is arranged at the top end of each vibrating diaphragm (502), a cavity (504) is formed between each group of substrates (501) and the corresponding vibrating diaphragm (502), and an air guide hole (505) is formed in the middle position of each vibrating diaphragm (502).

4. A novel micro-acoustic chip bottom-entry packaging structure as claimed in claim 3, wherein the bottom end of the cavity (504) is provided with an acoustic film (506).

5. The novel bottom entry package structure of micro acoustic chip as claimed in claim 4, wherein said sound absorbing film (506) is polyimide material.