CN218847489U

CN218847489U - Barometer

Info

Publication number: CN218847489U
Application number: CN202222582312.0U
Authority: CN
Inventors: 于文秀; 闫文明; 王新江
Original assignee: Rongcheng Gol Microelectronics Co ltd
Current assignee: Rongcheng Gol Microelectronics Co ltd
Priority date: 2022-09-28
Filing date: 2022-09-28
Publication date: 2023-04-11
Anticipated expiration: 2032-09-28

Abstract

The utility model provides a barometer, which comprises a substrate and a shell arranged on the substrate, wherein an encapsulation structure is formed between the substrate and the shell; the shell is provided with an air guide groove, the air guide groove extends downwards into the packaging structure, and the side wall of the air guide groove is provided with an air channel gap communicated with the packaging structure. The utility model provides a problem that the foreign matter was introduced easily to the gas pocket on the shell that barometer can solve current barometer.

Description

Barometer

Technical Field

The utility model relates to a barometer designs technical field, more specifically relates to a barometer.

Background

A barometer (barometer) is an instrument for measuring the absolute pressure of a gas, and is mainly suitable for physical experiments related to the pressure of the gas, such as the gas law.

The principle of the barometer in testing the air pressure is as follows: the change of the external air pressure is sensed by a sensitive film of a MEMS (Micro-Electro-Mechanical System) chip. Therefore, the MEMS chip requires a gas channel (e.g., a vent) with the test environment.

The packaging design of the existing small-size barometer is shown in fig. 1 and 2: the substrate 1 'and the shell 2' of the product form a packaging structure, the MEMS chip 3 'is arranged in the packaging structure, the MEMS chip 3' is electrically connected with the substrate through a gold wire 5', a large circular air hole 4' is designed right above the shell, and the size of the product is limited (the size of the air hole on the shell is usually set to be about phi 0.3mm (300 mu m), even larger, and too small to be easily blocked), and the air hole on the shell is difficult to completely avoid right above the MEMS chip (namely, a sensitive film of the MEMS chip has a part corresponding to the up-and-down position of the air hole on the shell); however, the sensitive size of the sensitive membrane of the MEMS chip is in the order of tens of μm to the foreign substance, so when the customer uses the product, if the cleanliness of the packaging environment is not guaranteed, the risk of the foreign substance entering the product will be increased due to the large air hole designed on the housing, which leads to the following technical problems:

1. foreign matters enter the air holes to the MEMS sensitive film, so that product failure or performance drift occurs on site;

2. the conductive foreign matter falls onto the gold wire connecting the chip and the substrate, resulting in a short circuit of the product.

3. The hole is too large and is over against the gold thread, and the sudden change of the air pressure of the external environment can cause the deformation or the fracture of the gold thread, thereby causing the abnormal connection or the abnormal performance of the product.

In view of the above technical problems, a structure capable of effectively preventing foreign matters from being easily introduced into the air hole of the housing of the barometer is needed.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, an object of the present invention is to provide a barometer to solve the problem that foreign matter is easily introduced into the air hole on the housing of the conventional barometer.

The utility model provides a barometer, which comprises a substrate and a shell arranged on the substrate, wherein an encapsulation structure is formed between the substrate and the shell; it is characterized in that the preparation method is characterized in that,

the shell is provided with an air guide groove, the air guide groove extends downwards into the packaging structure, and the side wall of the air guide groove is provided with an air channel gap communicated with the packaging structure.

Further, it is preferable that the height of the gas passage slit is in the order of μm.

In addition, it is preferable that the length of the gas passage slit is between 1/3 and 2/3 of the width of the housing.

In addition, the preferable structure is that a MEMS chip on the substrate is provided in the package structure; and the outlet end of the gas channel gap and the MEMS chip are arranged in a staggered mode in the vertical direction.

In addition, the preferred structure is that the MEMS chip is electrically connected to the substrate by gold wires; and the number of the first and second electrodes,

the outlet end of the gas channel gap and the gold wire are arranged in a staggered mode in the vertical direction.

In addition, the preferable structure is that the horizontal cross section of the air guide groove is in a polygonal structure; and the number of the first and second electrodes,

and at least one side wall of the air guide groove is provided with the air channel gap communicated with the packaging structure.

In addition, the preferable structure is that the horizontal cross section of the air guide groove is in a circular structure.

Further, it is preferable that the height of the gas passage slit is smaller than the height of the side wall of the gas guide groove.

In addition, it is preferable that the side wall of the air guide groove is formed integrally with the casing.

In addition, the substrate is preferably a pcb.

Compared with the prior art, the aforesaid is according to the utility model discloses a barometer has following beneficial effect:

the utility model provides a barometer sets up corresponding recess through the position of gas pocket on original shell to set up the gas channel gap that is used for the air guide on the lateral wall of recess, can enough balance the inside and external atmospheric pressure of packaging structure, can make the foreign matter (mainly non-mobile foreign matter) of recess top whereabouts again, keep in earlier in the recess and locate, can not get into the product through the gas channel gap inside, play the effect that blocks, keep apart the foreign matter, reduce the risk that the foreign matter got into.

Drawings

Other objects and results of the present invention will become more apparent and more readily appreciated as the same becomes better understood by reference to the following description and appended claims, taken in conjunction with the accompanying drawings.

In the drawings:

FIG. 1 is a front sectional view of a conventional barometer;

FIG. 2 is a top view of a prior art barometer;

fig. 3 is a front sectional view of the barometer provided by the present invention;

fig. 4 is a top view of the barometer provided by the present invention;

reference numerals: the MEMS chip comprises a substrate 1', a shell 2', an MEMS chip 3', air holes 4', gold wires 5', a substrate 1, a shell 2, an MEMS chip 3, air guide grooves 4, gold wires 5, a groove bottom wall 6 and gas channel gaps 7.

The same reference numbers in all figures indicate similar or corresponding features or functions.

Detailed Description

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that such embodiment(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.

Fig. 3 shows the utility model provides a section structure is looked to the owner of barometer, fig. 4 shows the utility model provides a barometer overlook the structure, combine fig. 3 and fig. 4 to know, the utility model provides a barometer forms packaging structure including being used for base plate 1 (like the pcb Board, printed Circuit Board) as basic Circuit Board and fixing shell 2 on base plate 1 between base plate 1 and the shell 2, and packaging structure's inside is used for setting up the functional device (like functional chip) of barometer, and shell 2 plays the guard action to functional device.

Specifically, for balancing the air pressure between the inside of the packaging structure and the outside and ensuring the measurement accuracy of the barometer, a groove (air guide groove 4) is arranged on the housing 2, a groove bottom wall 6 of the air guide groove 4 extends downwards to the inside of the packaging structure, and an air passage gap 7 which is transversely arranged (corresponding to the horizontal direction in the figure) and communicated with the packaging structure is arranged on a side wall (not marked in the figure) of the air guide groove 4, and the air pressure inside the packaging structure is balanced with the outside atmospheric pressure through the air passage gap 7.

The utility model provides a barometer is through setting up the air guide recess 4 that extends to packaging structure's inside on shell 2 to transversely set up the gas passage gap 7 that is linked together with packaging structure's inside on the lateral wall of air guide recess 4, can reach the inside and external atmospheric pressure of balanced packaging structure, can make the foreign matter of recess top whereabouts again, keep in earlier in the recess department, can not get into inside the product through gas passage gap 7, play and block, keep apart the effect of foreign matter, reduce the risk that the foreign matter got into.

It should be noted that the utility model provides a set up the height of gas passage gap 7 on the lateral wall of air guide groove 4 and set up to the mu m rank usually, and the size of the common foreign matter in the environment that this kind of mu m rank highly is less than the barometer, consequently, the foreign matter that drops to in the air guide groove 4 can not pass through the inside of the entering packaging structure of passage gap usually to play the effect of keeping apart the foreign matter, reduce the influence of foreign matter to the barometer performance.

It should be noted that, in general, the length of the gas passage slit 7 needs to be set between 1/3 and 2/3 of the width of the housing 2 (the overall length of the gas passage slit 7 is determined by the degree of influence of the foreign matters on the product, and is not further described here), so as to reduce the risk of the whole gas passage slit 7 being blocked by the foreign matters over a large area.

In a specific embodiment of the present invention, the MEMS chip 3 on the substrate 1 is disposed in the package structure, the MEMS chip 3 is a functional chip of the barometer, the sensing film is disposed on the MEMS chip 3, and the sensing film senses the external air pressure to measure the air pressure. Of course, in order to prevent the outlet end of the gas channel gap 7 from accidentally leaking a very small amount of foreign matter onto the MEMS chip 3 (or even onto the sensing film) and thereby affecting the performance of the entire barometer, the outlet end of the gas channel gap 7 needs to be disposed at a position displaced from the MEMS chip 3 up and down, that is, the outlet end of the gas channel gap 7 does not correspond to the MEMS chip 3 up and down (i.e., is disposed at a position displaced from the MEMS chip 3 up and down).

More specifically, in order to realize signal transmission between the MEMS chip 3 and the substrate 1, the MEMS chip 3 needs to be electrically connected to the substrate 1 through a gold wire 5. Of course, the exit end of gas channel gap 7 also need set up in the position that does not correspond from top to bottom with gold thread 5 (promptly with the dislocation set of position about gold thread 5), not only can prevent through this kind of setting that the few foreign matter that the exit end of gas channel gap 7 leaked carelessly from dropping to gold thread 5 on, influence the signal transmission between MEMS chip 3 and the base plate 1, can also avoid the gas flue of gas channel gap 7 just blowing the top of gold thread 5, the blowing power of buffering step grow atmospheric pressure to gold thread 5, reduce the cracked risk of gold thread 5.

In an alternative embodiment of the present invention, the horizontal cross section of the air guide groove 4 may be arranged in a polygonal structure, such as a triangle, a rectangle, a square, a pentagon, etc., and different numbers of side walls exist in the air guide grooves 4 with different structures, such as three side walls in the air guide grooves 4 with a triangular structure. Of course, in order to ensure that the air passage gap 7 can balance the air pressure inside the package structure with the outside, the air passage gap 7 communicated with the package structure may be provided on a plurality of side walls (at least one side wall) of the air guide groove 4, and the air pressure inside the package structure with the outside may be balanced by the plurality of air passage gaps 7.

Of course, in another alternative embodiment of the present invention, the horizontal cross section of the air guide groove 4 may also be configured as a circular structure, and for the air guide groove 4 with a circular structure, in order to ensure that the air passage gap 7 can balance the air pressure inside the package structure with the air pressure outside, the length of the air passage gap 7 may be increased or the number of the air passage gaps 7 may be increased appropriately.

It should be noted that, in general, the height of the gas passage slit 7 needs to be smaller than the height of the side wall of the gas guide groove 4, and by this arrangement, a certain height difference (not shown) can exist between the bottom wall of the gas guide groove 4 and the gas passage slit 7, thereby further improving the foreign matter isolation effect.

Of course, in the actual manufacturing process, the casing 2 can be made of metal materials or other hard materials commonly used, and in order to improve the direct connection performance between the air guide groove 4 and the casing 2, the side wall of the air guide groove 4 can be integrally formed with the casing 2.

A barometer according to the invention is described by way of example above with reference to fig. 3 and 4. However, it will be appreciated by those skilled in the art that various modifications may be made to the barometer proposed by the invention without departing from the scope of the invention. Therefore, the scope of the present invention should be determined by the content of the appended claims.

Claims

1. A barometer comprises a substrate and a shell arranged on the substrate, wherein an encapsulation structure is formed between the substrate and the shell; it is characterized in that the preparation method is characterized in that,

2. The barometer of claim 1,

the height of the gas channel gap is in the order of μm.

3. The barometer of claim 1,

the length of the gas passage slit is between 1/3 and 2/3 of the width of the housing.

4. The barometer of claim 1,

an MEMS chip on the substrate is arranged in the packaging structure; and also,

and the outlet end of the gas channel gap and the MEMS chip are arranged in a staggered manner in the vertical direction.

5. The barometer of claim 4,

the MEMS chip is electrically connected with the substrate through a gold wire; and also,

6. The barometer of claim 1,

the horizontal cross section of the air guide groove is of a polygonal structure; and the number of the first and second electrodes,

the gas channel gap is arranged on at least one side wall of the gas guide groove

7. The barometer of claim 1,

the horizontal cross section of the air guide groove is of a circular structure.

8. The barometer of claim 1,

the height of the gas channel gap is smaller than that of the side wall of the gas guide groove.

9. Barometer according to any of claims 1 to 8,

the side wall of the air guide groove and the shell are integrally formed.

10. The barometer of claim 1,

the base plate is the pcb board.