CN218465501U

CN218465501U - Integrated MEMS chip and ASIC chip stack packaged ultrasonic sensor

Info

Publication number: CN218465501U
Application number: CN202222493780.0U
Authority: CN
Inventors: 高伟; 马张权
Original assignee: Hefei Pilot Micro System Integration Co ltd
Current assignee: Hefei Pilot Micro System Integration Co ltd
Priority date: 2022-09-20
Filing date: 2022-09-20
Publication date: 2023-02-10
Anticipated expiration: 2032-09-20

Abstract

The utility model provides an integrated MEMS chip and ASIC chip pile up ultrasonic sensor of encapsulation, ultrasonic sensor includes: an ASIC chip package assembly; the MEMS chip packaging assembly is arranged on the ASIC chip packaging assembly, the MEMS chip packaging assembly and the ASIC chip packaging assembly are arranged in a stacked mode, and the MEMS chip packaging assembly is electrically connected with the ASIC chip packaging assembly; and the shell is arranged on the MEMS chip packaging assembly, and the shell is provided with a sound hole. The utility model provides an integrated MEMS chip and ASIC chip pile up ultrasonic sensor of encapsulation, this ultrasonic sensor is small, low power dissipation, easy assembly, can effectively promote ultrasonic sensor's transmission and sensitivity receiving simultaneously.

Description

Integrated MEMS chip and ASIC chip stack packaged ultrasonic sensor

Technical Field

The utility model relates to an ultrasonic sensor technical field especially relates to an integrated MEMS chip and ASIC chip pile up ultrasonic sensor of encapsulation.

Background

With the rapid development of the fields of consumer electronics, intelligent automobiles, intelligent homes and the like, the requirements on the performance, the size, the power consumption, the cost and the like of the ultrasonic sensor are higher and higher, and the optimized iteration speed of the piezoelectric ceramic ultrasonic sensor can not adapt to the iteration speed of the product requirement slowly, so that a bottleneck is reached, and a new breakthrough is difficult to occur; under the background, the MEMS ultrasonic sensor has a wide market in the future as a new generation of technical product.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome the above problem that prior art exists, provide an integrated MEMS chip and ASIC chip pile up ultrasonic sensor of encapsulation, this ultrasonic sensor is small, and low power dissipation, easy assembly can effectively promote ultrasonic sensor's transmission and sensitivity of reception simultaneously.

For realizing above-mentioned technical purpose, reach above-mentioned technological effect, the utility model discloses a following technical scheme realizes:

the utility model provides an integrated MEMS chip and ASIC chip pile up ultrasonic sensor of encapsulation, ultrasonic sensor includes:

an ASIC chip package assembly;

the MEMS chip packaging assembly is arranged on the ASIC chip packaging assembly, the MEMS chip packaging assembly and the ASIC chip packaging assembly are arranged in a stacked mode, and the MEMS chip packaging assembly is electrically connected with the ASIC chip packaging assembly; and

the shell is arranged on the MEMS chip packaging assembly, and the shell is provided with a sound hole.

In one embodiment of the present invention, the ASIC chip package assembly includes a first substrate; a frame disposed on the first substrate; and

and the ASIC chip is arranged on the first substrate and is positioned in the frame.

In an embodiment of the present invention, a first pad is disposed on the first substrate, and the first pad is located on the first substrate and close to one side of the frame.

In an embodiment of the present invention, a second bonding pad is disposed on the frame, and the second bonding pad is located on the frame near the first substrate and two sides of the MEMS chip package assembly.

In an embodiment of the present invention, the MEMS chip package assembly includes:

the second substrate is arranged on the frame and is positioned at one end, far away from the first substrate, of the frame; and

the MEMS chip is provided with a front cavity and a back cavity, the MEMS is arranged on the second substrate, and the MEMS chip is positioned on one side, far away from the frame, of the second substrate.

In an embodiment of the present invention, a third bonding pad is disposed on the second substrate, and the third bonding pad is located on the second substrate and close to one side of the frame.

In an embodiment of the present invention, a first adhesive layer is disposed between the first substrate and the frame, and the first adhesive layer is used to fix the frame on the first substrate.

In an embodiment of the present invention, a second adhesive layer is disposed between the second substrate and the frame, and the second adhesive layer is used to fix the second substrate on the frame.

In an embodiment of the present invention, a third adhesive layer is disposed between the housing and the second substrate, and the third adhesive layer is used to fix the housing on the second substrate.

The utility model discloses an in one embodiment, be provided with conductive adhesive layer between the first pad with the second pad, the second pad with between the third pad.

To sum up, the utility model provides an integrated MEMS chip and ASIC chip pile up ultrasonic sensor of encapsulation, this ultrasonic sensor is with ASCI chip and MEMS chip through the mode of piling up the encapsulation, set up the via hole through-hole technology on the frame, at the via hole, first pad, under the intercommunication effect of second pad and third pad, realize the MEMS chip, the ASIC chip piles up the electric connection between back first substrate and the second substrate, can reduce ultrasonic sensor's plane encapsulation size, and set up the sound hole on the shell, thereby form the structure of Helmholtz resonant cavity on ultrasonic sensor, can effectively promote ultrasonic sensor's transmission and the sensitivity of receiving.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without undue limitation to the invention. In the drawings:

fig. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is an exploded view of the overall structure of the MEMS chip of the present invention at one angle when it is being mounted;

fig. 3 is an exploded view of the overall structure at another angle when the MEMS chip of the present invention is being mounted;

FIG. 4 is a cross-sectional view of the MEMS chip of the present invention in its entirety;

FIG. 5 is an exploded view of the overall structure of the MEMS chip of the present invention at an angle when flipped;

fig. 6 is an exploded view of the MEMS chip of the present invention at another angle;

FIG. 7 is a cross-sectional view of the MEMS chip of the present invention in its inverted configuration;

fig. 8 is a schematic structural view of the frame of the present invention.

The numbering in the figures illustrates: 1-a first substrate, 2-a first adhesive layer, 3-a sound hole, 4-a housing, 5-a third adhesive layer, 6-a second substrate, 7-a second adhesive layer, 8-a frame, 9-a first pad, 10-a conductive adhesive layer, 11-a second pad, 12-a second conductive wire, 13-a MEMS chip, 14-an ASIC chip, 15-a first conductive wire, 16-a third pad, 17-a Helmholtz resonant cavity, 18-a first adhesive layer, 19-a second adhesive layer, 20-a solder ball, 21-a fourth pad, and 22-a via hole.

Detailed Description

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

Please refer to fig. 1 to 8, the utility model provides an integrated MEMS chip and ASIC chip pile up ultrasonic sensor of encapsulation, this ultrasonic sensor passes through via hole 22 lead wire on the frame 8, can realize UNICOM with first base plate 1 and second base plate 6, piles up MEMS chip 13 and ASIC chip 14, can reduce ultrasonic sensor's plane package size, and shell 4 sets up helmholtz resonant cavity 17 structure, can effectively promote ultrasonic sensor's transmission and receive sensitivity. The ultrasonic sensor comprises an ASIC chip packaging assembly, a MEMS chip packaging assembly and a shell 4, wherein the ASIC chip packaging assembly comprises a first substrate 1, a frame 8 and an ASIC chip 14, a first bonding pad 9 is arranged on the first substrate 1, and the first bonding pad 9 is positioned on one side, close to the frame 8, of the first substrate 1. The frame 8 is disposed on the first substrate 1, and the frame 8 is further provided with a second bonding pad 11, and the second bonding pad 11 is located on two sides of the frame 8 connected with the first substrate 1 and the MEMS chip package. A conductive adhesive layer 10 is arranged between the first bonding pad 9 and the second bonding pad 11, so that the first bonding pad 9 and the second bonding pad 11 are electrically conducted. The frame 8 is further provided with a via 22, and the via 22 can electrically connect the first substrate 1 and the MEMS chip package. A first adhesive layer 2 is further arranged between the frame 8 and the first substrate 1, and the frame 8 can be fixed on the first substrate 1 by the first adhesive layer 2. The ASIC chip 14 is disposed on the first substrate 1, and the ASIC chip 14 is located inside the frame 8. The ASIC chip 14 may be attached to the first substrate 1, and the ASIC chip 14 is further provided with a first conductive wire 15, one end of the first conductive wire 5 is connected to the ASIC chip 14, the other end of the first conductive wire 15 is connected to the first substrate 1, and the electrical connection between the ASIC chip 14 and the first substrate 1 is achieved through the first conductive wire 15.

Referring to fig. 1 to 7, in one embodiment of the present invention, the MEMS chip package assembly is disposed on the ASIC chip package assembly, and the MEMS chip package assembly and the ASIC chip package assembly are stacked, and the MEMS chip package assembly and the ASIC chip package assembly are electrically connected. Specifically, the MEMS package assembly includes a second substrate 6 and a MEMS chip 13, the second substrate 6 is disposed on the frame 8, and the second substrate 6 is located at an end of the frame 8 far away from the first substrate 1. The second substrate 6 is provided with third pads 16, and the third pads 16 are located on the second substrate 6 on a side close to the frame 8. The conductive adhesive layer 10 is also arranged between the third bonding pad 16 and the second bonding pad 11, so that the second bonding pad 11 and the third bonding pad 16 are electrically conducted. A second adhesive layer 7 is further arranged between the second substrate 6 and the frame 8, and the second adhesive layer 7 can be used for adhering and fixing the second substrate 6 on the frame 8. The MEMS chip 13 has a front cavity and a back cavity, the MEMS chip 13 is disposed on the second substrate 6, and the MEMS chip 13 is located on a side of the second substrate 6 away from the frame 8. The present application does not limit the mounting method between the MEMS chip 13 and the second substrate 6, and in an embodiment of the present invention, the MEMS chip 13 and the second substrate 6 may be mounted on the front side or the back side.

Referring to fig. 2 to 4, in an embodiment of the present invention, when the MEMS chip 13 and the second substrate 6 are assembled, the MEMS chip 13 can be attached on the second substrate 6, and the MEMS chip 13 is further provided with a second conductive wire 12, one end of the second conductive wire 12 is connected to the MEMS chip 13, the other end of the second conductive wire 12 is connected to the second substrate 6, and the electrical connection between the MEMS chip 13 and the second substrate 6 is realized through the second conductive wire 12. Referring to fig. 5 to 7, in an embodiment of the present invention, when the MEMS chip 13 is flipped over the second substrate 6, the MEMS chip 13 may be connected to the second substrate 6 through solder balls 20. Specifically, the second substrate 6 is further provided with a fourth pad 21, and the fourth pad 21 is located on a side of the second substrate 6 away from the frame 8. The fourth bonding pad 21 may be used for soldering the solder ball 20, so as to electrically connect the MEMS chip 13 and the second substrate 6. The solder balls 20 may be tin solder balls, but are not limited thereto. In an embodiment of the present invention, a conductive adhesive layer or a conductive silver paste layer can be dispensed on the fourth pad 21 by a dispenser, so as to electrically connect the MEMS chip 13 and the second substrate 6, thereby replacing the solder ball 20. A first sealing adhesive layer 28 is arranged at one end of the MEMS chip 13 far away from the second substrate 6, a second sealing adhesive layer 19 is arranged on the side wall of the MEMS chip 13, one end of the second sealing adhesive layer 19 is connected with the second substrate 6, and the other end of the second sealing adhesive layer 19 is connected with the MEMS chip 13.

Referring to fig. 1 to 7, in an embodiment of the present invention, the housing 4 is disposed on the MEMS chip package assembly, and the housing 4 is opened with the acoustic hole 3. The size and shape of the sound hole 3 in the present application can be determined according to the need, for example, it can be a circular hole, and it can also be a square hole, but not limited thereto. Specifically, the housing 4 is disposed on the second substrate 6, and a third adhesive layer 5 is further disposed between the housing 4 and the second substrate 6, where the third adhesive layer 5 can fix the housing 4 on the second substrate 6. The shell 4 can improve the integral rigidity of the ultrasonic sensor, improve the reliability, play a role in protecting the MEMS chip 13 and prevent the external world from causing structural damage to the MEMS chip 13. When the MEMS chip 13 is mounted, the housing 4, the second substrate 6 and the acoustic hole 3 together form a helmholtz resonator 17. When the MEMS chip 13 is flipped, the inner wall of the housing 4 abuts against the first sealant layer 18 to seal the back cavity of the MEMS chip 13 and the housing 4, so that the housing 4, the MEMS chip 13 and the acoustic hole 3 together form a helmholtz resonator 17. The helmholtz resonant cavity 17 can amplify signals of ultrasonic waves emitted by the MEMS chip 13 within a frequency band, and suppress signals outside the frequency band, thereby effectively improving the transmitting and receiving sensitivity of the ultrasonic sensor. The resonant frequency of the Helmholtz resonant cavity is calculated by

Where f is the resonant frequency of the helmholtz resonator 17, c is the speed of sound in air, V is the volume of the helmholtz resonator 17, S is the area of the acoustic hole 3, t is the wall thickness of the acoustic hole 3, a is the radius of the acoustic hole 3, and λ is a correction factor, for example, λ =1.3.

The foregoing shows and describes the basic principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the foregoing embodiments and descriptions are provided only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention.

Claims

1. An integrated MEMS chip and ASIC chip stack packaged ultrasonic sensor, comprising:

an ASIC chip package assembly;

2. The ultrasonic sensor of claim 1, wherein the ASIC chip package assembly comprises a first substrate;

a frame disposed on the first substrate; and

3. The ultrasonic sensor of claim 2, wherein the first substrate has first pads disposed thereon, the first pads being located on a side of the first substrate that is closer to the frame.

4. The ultrasonic sensor of claim 3, wherein the frame has second pads disposed thereon, the second pads being located on both sides of the frame proximate to the first substrate and the MEMS chip package assembly.

5. The ultrasonic sensor of claim 4, wherein the MEMS chip package assembly comprises:

6. The ultrasonic sensor of claim 5, wherein a third pad is disposed on the second substrate, the third pad being located on a side of the second substrate adjacent to the frame.

7. The ultrasonic sensor of claim 2, wherein a first adhesive layer is disposed between the first substrate and the frame, and the first adhesive layer is used to fix the frame on the first substrate.

8. The ultrasonic sensor of claim 5, wherein a second adhesive layer is disposed between the second substrate and the frame, and the second adhesive layer is used to fix the second substrate to the frame.

9. The ultrasonic sensor of claim 5, wherein a third adhesive layer is disposed between the housing and the second substrate, and the third adhesive layer is used to fix the housing to the second substrate.

10. The ultrasonic sensor according to claim 6, wherein a conductive adhesive layer is provided between the first pad and the second pad, and between the second pad and the third pad.