Packaging structure of pressure sensor

Abstract

The utility model relates to the technical field of pressure sensors, and provides a packaging structure of a pressure sensor, which comprises a detection part, a first connection part and a second connection part, the first connection part is provided with a base part connected with the second connection part and an extension part connected with the detection part, and the extension part and the base part form a stepped shaft structure; the detection part comprises a fixed cover and a pressure chip arranged in the fixed cover, the open end of the fixed cover is arranged on the first connecting part, and a plurality of through holes are formed in the sealed end of the fixed cover; a circuit board of the pressure chip is arranged in the first connecting part; a shielding wire penetrating through the second connecting part is arranged on the second connecting part, the shielding wire comprises at least one power supply sub-wire for supplying power to the pressure chip and a signal sub-wire for outputting a signal of the pressure chip, and the power supply sub-wire and the signal sub-wire are electrically connected and arranged on the circuit board. Therefore, the detected airflow can quickly and directly reach the pressure chip through the through hole, and the dynamic performance and accuracy of pressure detection are effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to pressure sensor technical field, concretely relates to a kind of packaging structure of pressure sensor. BACKGROUND

[0002] Pressure sensor is often used to detect the performance and parameters of equipment and products in modern industrial production process, and is widely used in various industries such as industrial production, aerospace, etc.

[0003] The packaging structure of pressure sensor is the core technology to realize the application of pressure sensor. In the prior art, the common MEMS piezoresistive pressure sensor usually adopts oil-filled packaging structure to achieve medium isolation. For example, the patent with application number CN201510564315.3 discloses a MEMS pressure sensor oil-filled core, which comprises a base, a cavity in the base, a pressure sensor packaging module exposed in the cavity and a medium filling the cavity. The base has a top and a bottom opposite to the top. The medium isolation type pressure sensor packaging structure further comprises a substrate cooperating with the bottom to seal the cavity. The substrate comprises a front surface, a back surface opposite to the front surface, and a lead wire penetrating through the front surface and the back surface. After the pressure sensor packaging module is fixed on the front surface, the substrate and the bottom are buckled and welded together. The pressure sensor packaging module is connected with the lead wire through wire bonding. The patent adopts oil-filled packaging method to set the pressure sensor packaging module inside the oil-filled cavity. The medium filling the oil-filled cavity is silicon oil, olive oil or other suitable medium. However, on the one hand, due to the filling of silicon oil, the dynamic performance will decrease, and the resonance frequency will decrease from hundreds of K to K. At the same time, too much internal silicon oil filling volume will also increase the output temperature drift of the pressure sensor, which will reduce the precision of the pressure sensor and is not suitable for high-frequency dynamic pressure measurement. On the other hand, the oil-filled packaging structure will increase the volume of the pressure sensor, making it difficult to realize miniaturization. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a kind of packaging structure of pressure sensor, to improve the problems of low measurement precision and poor dynamic performance of existing pressure sensor.

[0005] To achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

[0006] A packaging structure of pressure sensor, comprising a detection part, a first connecting part and a second connecting part, the first connecting part is provided with a base part connected with the second connecting part, and an extension part connected with the detection part, the extension part and the base part form a stepped shaft structure;

[0007] The detecting part comprises a fixed cover and a pressure chip arranged in the fixed cover, an open end of the fixed cover is arranged on the first connecting part, and a plurality of through holes are arranged on a closed end of the fixed cover;

[0008] The circuit board of the pressure chip is arranged in the first connecting part;

[0009] The second connecting part is provided with a shielding wire penetrating through the second connecting part, the shielding wire comprises at least one power supply sub-wire for supplying power to the pressure chip and a signal sub-wire for outputting a signal of the pressure chip, and the power supply sub-wire and the signal sub-wire are electrically connected to the circuit board.

[0010] Preferably, the detecting part is in a cylindrical structure, and a diameter of a cross section of the detecting part is 3.6-4 mm.

[0011] Preferably, the shielding wire further comprises a metal shielding net layer covering the signal sub-wire and the power supply sub-wire and a rubber layer covering the metal shielding net layer.

[0012] Preferably, the detecting part further comprises a fixing seat, the fixing seat is connected to the open end of the fixed cover, the pressure chip is arranged on the fixing seat, and a plurality of lead pins penetrating through the fixing seat are arranged on the fixing seat, and the pressure chip is electrically connected to the circuit board through the lead pins.

[0013] Preferably, the fixed cover comprises a cover shell and a separation plate, one end of the cover shell is connected to the fixing seat and arranged on the first connecting part, the separation plate is arranged on the other end of the cover shell to form the closed end, and the plurality of through holes are arranged on the separation plate.

[0014] Preferably, the through holes are 8-12 in number, and a diameter of the through holes is 0.1-0.3 mm.

[0015] Preferably, the detecting part, the first connecting part and the second connecting part are arranged in a welded manner.

[0016] Preferably, the pressure chip is arranged on the fixing seat in a glued manner.

[0017] Preferably, a threaded structure is arranged on an outer surface of the extending part.

[0018] Compared with the background art, the technical scheme has the following advantages:

[0019] 1. The utility model discloses a through hole is provided on the sealing end, can realize the isolation of foreign matter to outside on the basis of guaranteeing that the measured airflow passes, avoid the damage of foreign matter to pressure chip, make pressure sensor can use in different scenes, avoid the detection effect of complex environment influence pressure sensor, promote the accuracy of pressure sensor detection.

[0020] 2. The utility model discloses measured airflow can pass through the through hole directly to reach pressure chip, improve the dynamic performance of detection, can effectively avoid the pipe cavity effect caused by oil filling medium, and further improve the resonance, more suitable in the scene of high frequency pressure monitoring application.

[0021] 3. The utility model discloses the diameter of the cross section of detection part is 3.6mm~4mm, realize the miniaturization design of pressure sensor's probe, can reduce the influence to the measured airflow, and expand the applicable scene of pressure sensor. DRAWINGS

[0022] Figure 1 It is the sectional view of the packaging structure of pressure sensor of the utility model;

[0023] Figure 2 It is the sectional view of the detection part of the packaging structure of pressure sensor of the utility model;

[0024] Figure 3 It is the end face structure schematic drawing of the packaging structure of pressure sensor of the utility model.

[0025] Mark explanation:

[0026] 10, detection part, 101, fixed cover, 1011, cover shell, 1012, isolation plate, 10121, through hole;

[0027] 102, pressure chip, 103, fixed seat, 1031, lead pin;

[0028] 11, first connecting part, 111, base part, 112, extension, 1121, screw structure;

[0029] 113, circuit board;

[0030] 12, second connecting part, 121, shielded wire. Specific implementation

[0031] In order to make the utility model's purpose, technical scheme and advantage more clear and clear, the following is combined with the utility model and embodiment to carry out further detailed explanation. It should be understood that the specific embodiment described here is only used to explain the utility model, and is not used to limit the utility model.

[0032] In addition, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like are based on the orientation or positional relationship shown in the drawings, and are merely for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element of the present application must have a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0033] When an element is referred to as being "fixed to" or "set to" or "provided on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0034] Unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] Embodiment

[0036] Please refer to Figure 1 , Figure 2 and Figure 3As shown, the present embodiment provides a packaging structure of a pressure sensor, which comprises a detection part 10, a first connecting part 11 and a second connecting part 12, the first connecting part 11 is provided with a base part 111 connected with the second connecting part 12, and an extension part 112 connected with the detection part 10, the extension part 112 and the base part 111 form a stepped shaft structure, that is, the cross-sectional area of the base part 111 is larger than that of the extension part 112, the base part 111 is used for mounting a circuit board 113, and the extension part 112 is used for connecting with the detection part 10, the cross-sectional area of the extension part 112 is reduced to facilitate the installation of a miniature detection part 10, and the probe of the pressure sensor can be inserted into or connected with the measured pipeline for detection, which can be applied in smaller space for detection and has wide application scenarios. The detection part 10 comprises a fixed cover 101 and a pressure chip 102 arranged in the fixed cover 101, the open end of the fixed cover 101 is arranged on the first connecting part 11, and a plurality of through holes 10121 are arranged on the closed end of the fixed cover 101; the circuit board 113 of the pressure chip 102 is arranged in the first connecting part 11, the material of the circuit board 113 is an alumina ceramic substrate, which has good high temperature resistance; the second connecting part 12 is provided with a shielding wire 121 penetrating through itself, the shielding wire 121 comprises at least one power supply wire (not shown in the figure) for supplying power to the pressure chip 102 and a signal sub-wire (not shown in the figure) for outputting the signal of the pressure chip 102, and the power supply wire and the signal sub-wire are electrically connected and arranged on the circuit board 113.

[0037] Specifically, the measured gas flow can pass through the through holes 10121 on the fixed cover 101 and act on the pressure chip 102, the pressure chip 102 converts the pressure signal into an outputtable electrical signal after sensing the gas flow pressure, and transmits the electrical signal through the shielding wire 121, thereby realizing the detection of the pressure value of the measured gas flow.

[0038] Further, on the one hand, the through holes 10121 arranged on the closed end can realize the isolation of foreign matters from the outside on the basis of ensuring the passage of the measured gas flow, avoid the damage of the foreign matters to the pressure chip 102, so that the pressure sensor can be used in different scenarios, avoid the influence of complex environment on the detection effect of the pressure sensor, and improve the accuracy of the detection of the pressure sensor; on the other hand, compared with the traditional oil-filled packaging structure, the measured gas flow in the present embodiment can quickly pass through the through holes 10121 and directly reach the pressure chip 102, which improves the dynamic performance of the detection, effectively avoids the lumen effect caused by the oil-filled medium, and further improves the resonance, and is more suitable for application in the scene of high-frequency pressure monitoring.

[0039] As Figure 1 , Figure 2 and Figure 3As shown in the drawings, the detection part 10 in the embodiment is in a cylindrical structure, and the diameter of the cross section of the detection part 10 is 3.6mm-4mm. Preferably, the cross-sectional area of the detection part 10 is 3.8mm, so as to realize the design of miniaturization of the probe of the pressure sensor, reduce the influence on the measured air flow, and expand the application scenarios of the pressure sensor.

[0040] As shown in the drawings, Figure 1 As shown in the drawings, the shielding wire 121 in the embodiment further comprises a metal shielding mesh layer (not shown in the drawings) wrapping the signal sub-wire and the power supply sub-wire, and a rubber layer (not shown in the drawings) wrapping the metal shielding mesh layer. The shielding wire 121 is wrapped by the metal shielding mesh layer, so as to reduce the influence of external electromagnetic field on the wire, ensure the accuracy of signal transmission of the pressure sensor, and protect the shielding wire 121 by the rubber layer to avoid damage of the shielding wire 121.

[0041] As shown in the drawings, Figure 1 and Figure 2 As shown in the drawings, the detection part 10 in the embodiment further comprises a fixing seat 103 connected with the opening end of the fixing cover 101, and the pressure chip 102 is arranged on the fixing seat 103, so as to ensure the stability of the pressure chip 102. The fixing seat 103 is provided with a plurality of lead pins 1031 penetrating through the fixing seat 103, and the pressure chip 102 is electrically connected with the circuit board 113 through the lead pins 1031. The surface of the lead pins 1031 is plated with gold, and has good conductivity. The lead pins 1031 penetrate through the circuit board 113 and are soldered on the circuit board 113, so as to be electrically connected through the circuit board 113, and / or the shielding wire 121 is directly electrically connected with the lead pins 1031, so as to form power supply or signal transmission for the circuit board 113.

[0042] As shown in the drawings, Figure 2 As shown in the drawings, the fixing cover 101 in the embodiment comprises a cover shell 1011 and a separation plate 1012. One end of the cover shell 1011 is connected with the fixing seat 103 and arranged on the first connecting part 11, and the separation plate 1012 is arranged on the other end of the cover shell 1011 to form a sealing end, so as to isolate foreign matters from the outside, and avoid damage of the foreign matters to the pressure chip 102. A plurality of through holes 10121 are arranged on the separation plate 1012, so that the measured air flow passes through the separation plate 1012 to reach the pressure chip 102. The separation plate 1012, the cover shell 1011 and the fixing seat 103 can be connected by laser welding, so as to ensure the connection strength.

[0043] As shown in the drawings, Figure 3 As shown in the drawings, the number of the through holes 10121 is 8-12, and the diameter of the through holes 10121 is 0.1-0.3mm. Preferably, the number of the through holes 10121 is 8, and the diameter is 0.3mm. The 8 through holes 10121 are circumferentially distributed on the separation plate 1012, so as to facilitate the measured air flow to quickly pass through the through holes 10121 to reach the pressure chip 102.

[0044] As Figure 1 shown in the embodiment, the detection part 10, the first connecting part 11 and the second connecting part 12 are welded and connected. The material of the fixed cover 101 and the fixed seat 103 of the detection part 10, the first connecting part 11 and the second connecting part 12 is stainless steel material, which has good appearance gloss, strong corrosion resistance and good high temperature strength, can protect the internal components from damage during use, and can be connected by laser welding, which can ensure the connection strength and meet the air tightness requirement.

[0045] As Figure 1 and Figure 2 shown in the embodiment, the pressure chip 102 is glued on the fixed seat 103. For example, the solid crystal glue such as silica gel and epoxy resin can be used for gluing connection. The cured silica gel has good elasticity, small residual stress generated during installation of the pressure chip 102, and can ensure the stability of the pressure sensor.

[0046] As Figure 1 shown in the embodiment, the outer surface of the extension part 112 is provided with a threaded structure 1121. Since the measured pipeline usually has a connecting thread, the threaded structure 1121 is arranged on the extension part 112 to facilitate the stable connection of the pressure sensor and the measured pipeline, and further ensure the stability of the pressure sensor when detecting the airflow pressure.

[0047] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A package structure of a pressure sensor, characterized by, The probe part, the first connecting part and the second connecting part, the first connecting part is provided with a base part connected with the second connecting part, and an extension part connected with the probe part, the extension part and the base part form a stepped shaft structure; The probe part includes a fixed cover and a pressure chip arranged in the fixed cover, an open end of the fixed cover is arranged on the first connecting part, and a plurality of through holes are arranged on a closed end of the fixed cover; The circuit board of the pressure chip is arranged in the first connecting part; The second connecting part is provided with a shielding line penetrating through itself, the shielding line includes at least one power supply sub-line for supplying power to the pressure chip and a signal sub-line for outputting a signal of the pressure chip, and the power supply sub-line and the signal sub-line are electrically connected and arranged on the circuit board.

2. The package structure of a pressure sensor according to claim 1, characterized by: The probe part is in a cylindrical structure, and a diameter of a cross section of the probe part is 3.6mm-4mm.

3. The package structure of a pressure sensor according to claim 1, characterized by: The shielding line further includes a metal shielding mesh layer covering the signal sub-line and the power supply sub-line, and a rubber layer covering the metal shielding mesh layer.

4. The package structure of a pressure sensor according to claim 1, characterized by: The probe part further includes a fixed seat connected with the open end of the fixed cover, the pressure chip is arranged on the fixed seat, and a plurality of lead pins penetrating through the fixed seat are arranged on the fixed seat, the pressure chip is electrically connected with the circuit board through the lead pins.

5. The package structure of a pressure sensor according to claim 4, characterized by: The fixed cover includes a cover shell and a separation plate, one end of the cover shell is connected with the fixed seat and arranged on the first connecting part, the separation plate is arranged on the other end of the cover shell to form the closed end, and a plurality of through holes are arranged on the separation plate.

6. The package structure of a pressure sensor according to claim 5, wherein: The through holes are arranged in 8-12, and a diameter of the through holes is 0.1-0.3mm.

7. The package structure of a pressure sensor according to claim 1, wherein: The probe part, the first connecting part and the second connecting part are arranged in a welding connection mode.

8. The package structure of a pressure sensor according to claim 4, wherein: The pressure chip is arranged on the fixed seat in a gluing mode.

9. The package structure of a pressure sensor according to claim 1, wherein: A threaded structure is arranged on an outer surface of the extension part.

Images