CN217323376U

CN217323376U - Packaging structure of MEMS chip

Info

Publication number: CN217323376U
Application number: CN202121361408.3U
Authority: CN
Inventors: 唐行明; 梅嘉欣
Original assignee: Memsensing Microsystems Suzhou China Co Ltd
Current assignee: Memsensing Microsystems Suzhou China Co Ltd
Priority date: 2021-06-18
Filing date: 2021-06-18
Publication date: 2022-08-30
Anticipated expiration: 2031-06-18

Abstract

Disclosed is a packaging structure of a MEMS chip, comprising: a substrate having at least one first groove formed in a first surface thereof; the MEMS chip is positioned above the substrate; the MEMS chip is provided with at least one first supporting structure and a second supporting structure on a second surface facing the substrate; the position of the first supporting structure corresponds to the position of the first groove and is positioned in the first groove, wherein the second supporting structure is used for adjusting the position and the distance relation between the MEMS chip and the substrate. The application discloses packaging structure of MEMS chip forms a plurality of first bearing structure through the second surface at the MEMS chip to be connected through first bearing structure and base plate, make the area of contact of MEMS chip and base plate less, reduced the transmission of stress, improved MEMS chip's sensitivity.

Description

Packaging structure of MEMS chip

Technical Field

The utility model relates to a sensor technical field, in particular to packaging structure of MEMS chip.

Background

MEMS (micro electro Mechanical Systems) pressure sensors can be produced in large scale with high precision and low cost by using a design technology and a manufacturing process similar to Integrated Circuits (ICs), so that a door is opened for using a large amount of MEMS sensors with low cost for consumer electronics and industrial process control products, and pressure control becomes simple, easy to use and intelligent.

At present, a commonly used MEMS sensor in the industry is a bottom plane, and is bonded with a substrate by adopting silica gel, and when stress is generated on the substrate, the stress is transmitted to an MEMS chip through the silica gel, so that the stress is generated on the MEMS chip, and the sensitivity of a product is influenced.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, an object of the present invention is to provide a package structure of a MEMS chip, which reduces the transmission of stress by reducing the contact area of the glue between the MEMS chip and the substrate.

According to an aspect of the utility model, a packaging structure of MEMS chip is provided, include: a substrate having at least one first groove formed in a first surface thereof; the MEMS chip is positioned above the substrate; the MEMS chip is provided with at least one first supporting structure and a second supporting structure on a second surface facing the substrate; the position of the first supporting structure corresponds to the position of the first groove and is positioned in the first groove, and the second supporting structure is used for adjusting the position and the distance relation between the MEMS chip and the substrate.

Optionally, the height of the second support structure is less than the height of the first support structure.

Optionally, the number of the first grooves is one, and the bottom of the at least one first support structure is located in the first groove.

Optionally, the method further comprises: and the second surface of the limiting block is bonded in the first groove, and the first supporting structure is separated by the limiting block.

Optionally, a second groove is formed in the first surface of the stopper, the second groove is used for accommodating the second support structure, and the first surface of the stopper is opposite to the second surface.

Optionally, the bottom of the second support structure contacts the bottom of the second groove in the stopper.

Optionally, the depth of the second groove is less than or equal to the height of the second support structure.

Optionally, the first grooves are multiple, the positions of the first grooves correspond to the first support structures one to one, and the shape of each first groove is matched with the shape of the corresponding first support structure.

Optionally, a bottom of the second support structure is in contact with the first surface of the substrate.

Optionally, the height of the first support structure and the second support structure is greater than zero, and the height of the first support structure is greater than the depth of the first groove.

Optionally, a plurality of the first support structures have at least one height.

Optionally, the bottom of the first support structure has a concave-convex structure, and the bottom of the first groove has a shape matching the concave-convex structure.

Optionally, a cross-sectional shape of the first support structure and the second support structure along the second surface of the MEMS chip is any one of a rectangle, a circle, a triangle, or a quadrangle.

Optionally, the MEMS chip further includes a pressure sensitive membrane and a second cavity, and the pressure sensitive membrane is located above the second cavity.

Optionally, the method further comprises: the packaging shell is fixed on the first surface of the substrate, a first cavity is formed between the packaging shell and the substrate, and the MEMS chip is located in the first cavity; and the ASIC chip is arranged on the first surface of the substrate in the first cavity and is electrically connected with the MEMS chip.

The utility model provides a MEMS chip forms a plurality of first bearing structure of column on the second surface, is connected through between first bearing structure and the base plate to area of contact between MEMS chip and the base plate has been reduced, and then makes when the base plate warp and produces stress, has reduced the transmission of stress from the base plate to MEMS chip.

In a preferred embodiment, a second supporting structure is further formed on the second surface of the MEMS chip, and the second supporting structure is used for limiting the position of the MEMS chip on the surface of the substrate and the distance between the MEMS chip and the substrate, so that the position of the MEMS chip does not change too much.

The utility model provides an among the packaging structure of MEMS chip, in the first surface of base plate, be formed with first recess, the shape of first recess and the shape phase-match of the first bearing structure of MEMS chip to after fixing MEMS chip and base plate, the MEMS chip can not lead to unstable with being connected of base plate because of the area of contact with glue reduces.

In a preferred embodiment, a limiting block is further arranged in the first groove on the first surface of the substrate, the limiting block is connected with the bottom of the first groove of the substrate, a second groove is formed in the surface of one side, facing the MEMS chip, of the limiting block, and the second groove is matched with the second support structure of the MEMS chip in shape and used for accommodating the second support structure and limiting the position of the MEMS chip.

In a preferred embodiment, the height, width, cross-sectional shape, and the like of the plurality of first supporting structures of the MEMS chip are two or more in at least one aspect, which can further improve the connection stability between the MEMS chip and the substrate.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

fig. 1 shows a schematic diagram of a packaging structure of a MEMS chip according to an embodiment of the present invention;

fig. 2 shows a partial schematic view in a dashed-line frame M in a package structure of a MEMS chip according to a first embodiment of the present invention;

fig. 3a shows a perspective view of a MEMS chip according to a first embodiment of the present invention;

figure 3b shows a top view of the base plate according to the first embodiment of the present invention;

fig. 4a shows a partial schematic view in a dashed box M in a package structure of a MEMS chip according to a second embodiment of the present invention;

figure 4b shows a top view of the base plate according to a second embodiment of the invention;

fig. 5 shows a partial schematic view in a dashed-line frame M in a package structure of a MEMS chip according to a third embodiment of the present invention;

fig. 6 is a partial schematic view of a package structure of a MEMS chip according to a fourth embodiment of the present invention.

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by like reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale. In addition, certain well known components may not be shown. For simplicity, the semiconductor structure obtained after several steps can be described in one figure.

It will be understood that when a layer or region is referred to as being "on" or "over" another layer or region, it can be directly on the other layer or region or intervening layers or regions may also be present in the structure of the device. And, if the device is turned over, that layer, region, or regions would be "under" or "beneath" another layer, region, or regions.

If for the purpose of describing the situation directly above another layer, another area, the expression "directly above … …" or "above and adjacent to … …" will be used herein.

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples.

Fig. 1 shows a schematic diagram of a packaging structure of a MEMS chip according to an embodiment of the present invention; fig. 2 shows a partial schematic view in a dashed-line frame M in a package structure of a MEMS chip according to a first embodiment of the present invention; fig. 3a shows a perspective view of a MEMS chip according to a first embodiment of the present invention; fig. 3b shows a top view of the base plate according to the first embodiment of the present invention, wherein fig. 2 shows an enlarged view of the dashed box M in fig. 1.

Referring to fig. 1 and 2, the package structure of the MEMS chip of the present application includes a substrate 20, a first groove 21 formed in a first surface of the substrate 20; the package housing 50 is fixed on the first surface of the substrate 20, and a first cavity 51 is formed between the package housing 50 and the substrate 20; the MEMS chip 10 is arranged in the first cavity 51, and the MEMS chip 10 comprises a second cavity 11, a pressure sensitive film positioned above the second cavity 11 and a support structure positioned below the second cavity 11; and an ASIC chip 60 disposed on the first surface of the substrate 20 in the first cavity 51, wherein the ASIC chip 60 is an application specific integrated circuit chip and is connected to the MEMS chip 10 by a wire.

In this embodiment, the substrate 20 may be made of a conventional substrate material such as RF-4, BT or ceramic substrate. A sealing ring surrounding along the edge of the first surface of the substrate 20 is further formed on the first surface of the substrate 20, and the package housing 50 is fixedly connected with the first surface of the substrate 20 through the sealing ring to form a first cavity 51. Pads are formed on the second surface of the substrate 20 for providing electrical connection points. The substrate 20 may be a single-layer or multi-layer circuit board, and the first surface of the substrate 20 may also be formed with circuit structures, or electrical contacts, such as pads, etc. The substrate 20 may further have an electrical connection structure formed therein for connecting electrical contacts of the first surface and the second surface of the substrate 20.

The package housing 50 serves as a package housing of the vibration sensor package structure, and is used for protecting the internal electronic components, and a first cavity 51 is formed between the package housing and the substrate 20. The packaging shell 50 can be made of metal, is high temperature resistant, is simple in production process, and can be produced in large scale, and the metal shell packaging shell 50 also has the characteristics of corrosion resistance, electromagnetic shielding effect, high mechanical property and the like, so that the product is protected well. In other embodiments, the package housing 50 may also be made of other hard materials such as plastic, which is not limited herein. The edge of the package housing 50 is fixed to the sealing ring on the first surface of the substrate 20 by welding or gluing, so that a first cavity 51 is formed between the package housing 50 and the substrate 20.

The MEMS chip 10 acts as a sensing element for acoustic signals, with its pressure sensitive membrane located over the second cavity. Since the substrate 20 is deformed when the second surface of the MEMS chip 10 is directly adhered to the first surface of the substrate 20, the stress reaches the MEMS chip 10 through the adhesive, and the sensitivity of the MEMS chip 10 is affected, so that the present application improves this part.

Referring to the structure diagram 100 of the first embodiment shown in fig. 2, the MEMS chip 10 of the present application includes a pressure sensitive film located above the second cavity 11 and a supporting structure located below the second cavity 11, wherein the pressure sensitive film is located on a first surface of the MEMS chip 10, the supporting structure is located on a second surface of the MEMS chip 10, and the pressure sensitive film is used for sensing pressure and generating deformation.

Further, on the second surface of the MEMS chip 10, the support structure includes a first support structure 13 and a second support structure 12. The height of the first support structure 13 and the second support structure 12 is greater than zero and the height of the first support structure 13 is not less than the height of the second support structure 12, and the width of the first support structure 13 and the second support structure 12 is less than the width of the MEMS chip 10, as shown in fig. 3 a. Importantly, in the embodiment of the present invention, the MEMS chip 10 and the substrate 20 are not directly attached to each other, but are in contact with the first surface of the substrate 20 through the first supporting structure 13 and the second supporting structure 12 on the second surface of the MEMS chip 10, so that the contact area between the sensor chip and the substrate is reduced, and then the process of transmitting the stress generated by the deformation of the substrate 20 to the MEMS chip 10 by the substrate 20 is weakened, the influence on the MEMS chip 10 is reduced, and the sensitivity of the MEMS chip 10 is improved.

The material of the first support structure 13 and the second support structure 12 is, for example, Si or a Si-containing compound or other supportable materials.

In this embodiment, the MEMS chip 10 is formed with four first supporting structures 13 and one second supporting structure 12, wherein the first supporting structures 13 are uniformly distributed on the second surface of the MEMS chip 10 near the edge, and the second supporting structure 12 is located in the middle area of the second surface of the MEMS chip 10. The cross-sectional shapes of the first support structure 13 and the second support structure 12 along the second surface of the MEMS chip 10 are any one of a rectangle, a circle, a triangle, or a quadrangle. In the embodiment shown in fig. 3a, the cross-sectional shape of the four first support structures 13 is the same, and the height of the four first support structures 13 is the same, while the height of the second support structure 12 is smaller than the height of the first support structure 13.

Further, referring to fig. 2, and the top view of the substrate 20 shown in fig. 3b, four first grooves 21 are formed at corresponding positions of the substrate 20. The positions and shapes of the four first grooves 21 are correspondingly matched with the positions and shapes of the first support structures 13 on the second surface of the MEMS chip 10, that is, when the MEMS chip 10 is mounted, the four first grooves 21 in the first surface of the substrate 20 can correspondingly accommodate the bottoms of the four first support structures 13 on the second surface of the MEMS chip 10, and the first support structures 13 are fixedly connected with the substrate 20 through the glue 30. Glue 30 coats the bottom of the first support structure 13 and the sides near the bottom.

Further, the height of the first supporting structure 13 in the MEMS chip 10 is not less than the depth of the first groove 21 in the substrate 20, i.e. after the first supporting structure 13 is fixed in the first groove 21, there is a certain height between the second surface of the MEMS chip 10 and the first surface of the substrate 10. Furthermore, the bottom of the second support structure 12 is in contact with the first surface of the substrate 20, and it can be understood that by changing the height of the second support structure 12, the distance between the second surface of the MEMS chip 10 and the first surface of the substrate 10 can be adjusted.

In the embodiment shown in fig. 2, in order to make the connection manner between the MEMS chip 10 and the substrate 20 easier to understand, the width of the first groove 21 is greater than the width of the first support structure 13, that is, there is a gap between the first support structure 13 and the sidewall and the bottom of the first groove 21 of the substrate 20. In other embodiments, however, the width of the first groove 21 may be decreased or the width of the first support structure 13 may be increased accordingly, so as to decrease the gap between the sidewalls and the bottom of the first groove 21 of the first support structure 13 and the substrate 20, thereby increasing the stability of the connection between the MEMS chip 10 and the substrate 20.

In other embodiments, the number of the first supporting structures 13 of the MEMS chip 10 may also be any number greater than one, and a plurality of the first supporting structures 13 may be disposed at any position of the second surface of the MEMS chip 10 as needed.

Fig. 4a shows a partial schematic view in a dashed box M of a package structure of a MEMS chip according to a second embodiment of the present invention; fig. 4b shows a top view of the base plate in a second embodiment according to the invention. Compared with the first embodiment, the difference of the package structure of the MEMS chip of the second embodiment is that the first groove of the substrate is different, and the same parts are not described herein again, and only the difference is described.

Referring to fig. 4a, in the second embodiment, one first recess 21 is formed in the first surface of the substrate 20, and the first recess 21 can accommodate a plurality of first supporting structures 13 of the MEMS chip 10. However, a limiting block 40 is further bonded in the first groove 21, and a second surface of the limiting block 40 is bonded with the bottom of the first groove 21 through a glue body 41.

Further, referring to the top view of the substrate 20 shown in fig. 4b, at the position where the first groove 21 corresponds to the first supporting structure 13 of the MEMS chip 10, a corresponding space is formed between the stopper 40 and the first groove 21 for accommodating the plurality of first supporting structures 13 of the MEMS chip 10. In this embodiment, the space formed between the stopper 10 and the first groove 21 matches the shape, size and position of the first support structure 13.

Further, in the first surface of the stopper 40, a second groove 42 is formed, and the shape, size and position of the second groove 42 are all matched with the second supporting structure 12 of the MEMS chip 10, that is, after the MEMS chip 10 is connected to the substrate 20, the first supporting structure 13 of the MEMS chip 10 is located in the first groove 21, and the second supporting structure 12 is located in the second groove. The limiting block 40 is made of metal or nonmetal, and the colloid 41 adhering the second surface of the bottom of the limiting block 40 and the first groove 21 is solder paste or other adhesives.

Preferably, the height of the second support structure 12 is consistent with the depth of the second groove 42, and when the bottom of the second support structure 12 contacts the bottom of the second groove 42, the first surface of the stopper 40 contacts the second surface of the MEMS chip 10.

In other embodiments, the height of the second support structure 12 and the depth of the second groove 42 may not be the same, for example, the height of the second support structure 12 is greater than the depth of the second groove 42, at this time, the second support structure 12 may contact the bottom of the second groove 42, but the first surface of the stopper 40 cannot contact the second surface of the MEMS chip 10, at this time, the stopper 40 only serves to limit the position of the MEMS chip 10, and cannot adjust the height between the second surface of the MEMS chip 10 and the first surface of the substrate 20.

In this embodiment, the position of the MEMS chip 10 is limited by the limiting block 40, and the stability of the connection between the MEMS chip 10 and the substrate 20 is improved together with the first groove 21 and the glue 30, so that the MEMS chip 10 can be stably connected even if the contact area with the substrate 20 is reduced, and the sensitivity is improved due to the reduction of the contact area. Further, the distance between the MEMS chip 10 and the substrate 20 can be adjusted by the height of the stopper 40.

Fig. 5 is a partial schematic view of a package structure of a MEMS chip according to a third embodiment of the present invention. Compared with the first embodiment, the third embodiment is different in that the plurality of first supporting structures 13 in the MEMS chip 10 are different, and the same parts are not described herein, and only the different parts are described.

Referring to fig. 5, in a third embodiment, a plurality of first support structures 13 are formed on the second surface of the MEMS chip 10, and the second support structures may be absent or present. Wherein the plurality of first support structures 13 have at least two heights and correspondingly, the plurality of first recesses 21 formed in corresponding locations of the substrate 20 also have at least two depths for accommodating the first support structures 13 of the corresponding heights, thereby ensuring that the first surface of the finally mounted MEMS chip 10 is level with the first surface of the substrate 20.

Further, in this embodiment, the widths of the plurality of first supporting structures 13 may also be at least two. Further, the cross-sectional shapes of the plurality of first supporting structures 13 along the first surface direction of the MEMS chip 20 may also be at least two. In the case where the plurality of first support structures 13 have two or more kinds of height, width, cross-sectional shape, and the like, the connection stability of the MEMS chip 10 and the substrate 20 may be increased.

Fig. 6 is a partial schematic view of a package structure of a MEMS chip according to a fourth embodiment of the present invention. Compared with the first embodiment or the third embodiment, the bottom of the first supporting structure 13 in the fourth embodiment is different, and the same parts are not described again, and only the differences are described.

Referring to fig. 6, in the fourth embodiment, a plurality of first supporting structures 13 are formed on the second surface of the MEMS chip 10, and the second supporting structures may be absent or present. Wherein, the concave-convex structure 14 is formed at the bottom of the first supporting structure 13, correspondingly, the bottom of the plurality of first grooves 21 formed in the corresponding position of the substrate 20 is also formed with a matched concave-convex structure, so that the first grooves 21 can better accommodate the first supporting structure 13. The concave-convex structure 14 is, for example, a step structure, a sawtooth structure, or the like.

Further, at least one aspect of the height, width, cross-sectional shape, and the like of the plurality of first supporting structures 13 may also have two or more kinds, so as to increase the connection stability between the MEMS chip 10 and the substrate 20.

In accordance with the embodiments of the present invention as set forth above, these embodiments are not exhaustive and do not limit the invention to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and its various embodiments with various modifications as are suited to the particular use contemplated. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A packaging structure of a MEMS chip is characterized by comprising:

a substrate having at least one first groove formed in a first surface thereof;

the MEMS chip is positioned above the substrate;

the MEMS chip is provided with at least one first supporting structure and a second supporting structure on a second surface facing the substrate;

the position of the first support structure corresponds to the position of the first groove and is positioned in the first groove,

the second support structure is used for adjusting the position and the distance relation between the MEMS chip and the substrate.

2. The package structure of claim 1, wherein a height of the second support structure is less than a height of the first support structure.

3. The package structure of claim 2, wherein the first recess is one, and the bottom of the at least one first support structure is located in the first recess.

4. The package structure of claim 3, further comprising: and the second surface of the limiting block is bonded in the first groove, and the first supporting structure is separated by the limiting block.

5. The packaging structure of claim 4, wherein the first surface of the stop has a second recess formed therein for receiving the second support structure, the first surface of the stop being opposite the second surface.

6. The package structure of claim 5, wherein a bottom of the second support structure contacts a bottom of the second recess in the stopper.

7. The package structure of claim 5, wherein a depth of the second recess is less than or equal to a height of the second support structure.

8. The package structure of claim 2, wherein the first recesses are plural and located in a one-to-one correspondence with the first support structures, and each of the first recesses has a shape matching a shape of the corresponding first support structure.

9. The package structure of claim 8, wherein a bottom of the second support structure is in contact with the first surface of the substrate.

10. The package structure of claim 2, wherein the height of the first and second support structures is greater than zero, and the height of the first support structure is greater than the depth of the first recess.

11. The package structure of claim 1, wherein the plurality of first support structures have at least one height.

12. The package structure according to claim 1, wherein the bottom of the first support structure has a concave-convex structure, and the bottom of the first groove has a shape matching the concave-convex structure.

13. The package structure of claim 1, wherein a cross-sectional shape of the first and second support structures along the second surface of the MEMS chip is any one of a rectangle, a circle, a triangle, or a quadrilateral.

14. The package structure of claim 1, wherein the MEMS chip further comprises a pressure sensitive membrane and a second cavity, the pressure sensitive membrane being located over the second cavity.

15. The package structure of claim 1, further comprising:

the packaging shell is fixed on the first surface of the substrate, a first cavity is formed between the packaging shell and the substrate, and the MEMS chip is located in the first cavity;

and the ASIC chip is arranged on the first surface of the substrate in the first cavity and is electrically connected with the MEMS chip.