All-metal shell pressure sensor

Abstract

The invention belongs to the technical field of pressure sensors, and particularly relates to an all-metal shell pressure sensor which comprises an upper shell and a lower shell, a plurality of mounting holes are formed in the outer side wall of the upper shell, contact pins are arranged in the mounting holes, and connecting sleeves are fixedly connected between the upper shell and the contact pins. A connecting plate is fixedly connected between the ends, facing the lower shell, of the connecting sleeves, a circuit board is fixedly connected between the upper shell and the lower shell, and the ends, away from the upper shell, of the contact pins penetrate through the connecting plate and the circuit board and extend into the lower shell. The beneficial effects of the invention are that through the arrangement of the mounting hole and the connecting sleeve and the connecting plate which are made of insulating rubber, the functions of fixing, sealing, insulating and the like of the contact pin can be realized when the contact pin is connected with the upper shell, the assembly of the contact pin is facilitated, the processing difficulty is reduced, and the processing cost is effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure sensors, in particular to a full-metal shell pressure sensor. BACKGROUND

[0002] A pressure sensor is a device or apparatus that can sense a pressure signal and convert it into a measurable electrical signal (such as voltage, current, or frequency), and is widely used in many fields such as industry, medicine, consumer electronics, aerospace, etc. MEMS pressure sensors are based on micro-electro-mechanical system technology, which converts physical deformation into electrical signals to measure pressure. It uses the piezoresistive effect of semiconductor materials, where pressure causes the silicon membrane to deform, and the embedded piezoresistive resistor changes in resistance, which is converted into a voltage signal through a Wheatstone bridge.

[0003] For example, CN114348952B discloses a MEMS pressure sensor packaging structure, which comprises a group of oppositely arranged metal plates on the inner side wall of the shell. When a voltage is applied to the metal plates, an electric field is formed. According to the dielectric separation effect, under the action of the electric field, the external dirt that penetrates into the sealed cavity moves and gathers towards the metal plates, and falls into the dirt collection groove at the bottom of the metal plates under the action of gravity. This solves the problem of gradual decline in packaging airtightness with increasing working time of the sensor, which causes external dirt to sink to the surface of the MEMS pressure sensor chip after entering the packaging cavity, thereby causing a decline in sensor performance.

[0004] The above-mentioned pressure sensor adopts a metal shell, and the output pins of the common metal shell pressure sensor are mainly fixed, sealed and insulated by a glass sintering process. However, the glass sintering process has the following problems: the pin material needs to be an iron-nickel alloy with a similar expansion coefficient to the glass glue, which is difficult to process and has a high cost; the metal shell after high-temperature sintering will have a poor appearance of an oxidation layer, which needs to be surface treated by processes such as pickling, electroplating and sandblasting; in order to achieve the best conductivity, the pin material generally needs to be electroplated after sintering, and since the metal shell has been sintered together with the pin material, only a local electroplating process can be used, which is low in efficiency and high in cost. SUMMARY

[0005] The present application aims to solve the problem of the existing metal shell sensor using a glass sintering process, which is not convenient to process and has a high cost.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A full metal shell pressure sensor, comprising an upper shell and a lower shell, a plurality of mounting holes are formed on the outer side wall of the upper shell, a plurality of insertion pins are arranged in the mounting holes, a plurality of connecting sleeves are fixedly connected between the upper shell and the insertion pins, a plurality of connecting sleeves are fixedly connected between the connecting sleeves and the lower shell, a connecting plate is fixedly connected between the upper shell and the lower shell, a circuit board is fixedly connected between the upper shell and the lower shell, and the insertion pins extend to the inside of the lower shell through the connecting plate and the circuit board.

[0008] Further, the connecting sleeve and the connecting plate are made of insulating rubber.

[0009] Further, the upper shell and the lower shell are circularly arranged, and the upper shell and the lower shell are made of metal material.

[0010] Further, a sealed cavity is arranged between the upper shell and the circuit board, and a filler is arranged in the sealed cavity.

[0011] Further, the filler is made of hard epoxy glue.

[0012] Further, a glue injection port and an exhaust port are formed on the edge of the circuit board.

[0013] Further, an ASIC chip is fixedly connected to the side of the circuit board facing the upper shell, and a MEMS chip is fixedly connected to the side of the circuit board facing the lower shell.

[0014] Further, a pressure inlet hole is formed at the axis of the lower shell.

[0015] Further, the ASIC chip and the MEMS chip are arranged along the axis deviating from the pressure inlet hole.

[0016] Further, the upper shell and the lower shell are sealed by laser welding or adhesive bonding.

[0017] Compared with the prior art, the beneficial effects of the present application are as follows:

[0018] 1. The full metal shell pressure sensor of the present application can realize the functions of fixing, sealing and insulating the insertion pin when the insertion pin is connected to the upper shell by arranging the mounting hole, the connecting sleeve made of insulating rubber and the connecting plate, which facilitates the assembly, reduces the processing difficulty and effectively reduces the processing cost.

[0019] 2. The full metal shell pressure sensor of the present application can further seal and fix the insertion pin, and protect the surface of the circuit board by arranging the sealed cavity and the filler, which can avoid the corrosion of the medium to the components on the surface of the circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1It is a whole structure schematic diagram of a full metal shell pressure sensor of the present application.

[0021] Figure 2 It is a side view structure schematic diagram of a full metal shell pressure sensor of the present application.

[0022] Figure 3 It is an explosion structure schematic diagram of a full metal shell pressure sensor of the present application.

[0023] Figure 4 It is a whole structure sectional view schematic diagram of a full metal shell pressure sensor of the present application.

[0024] Figure 5 It is an upper shell and connecting sleeve sectional view structure schematic diagram of a full metal shell pressure sensor of the present application.

[0025] In the figure: 1, upper shell; 2, lower shell; 3, pin; 4, connecting sleeve; 5, mounting hole; 6, circuit board; 7, ASIC chip; 8, connecting plate; 9, filler; 10, MEMS chip; 11, sealed cavity; 12, pressure inlet hole; 13, glue injection port; 14, exhaust port. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] Please refer to Figures 1-5 The full metal shell pressure sensor of the present embodiment comprises an upper shell 1 and a lower shell 2. The outer side wall of the upper shell 1 is provided with a plurality of mounting holes 5. The inside of the mounting hole 5 is provided with a pin 3. The connecting sleeve 4 is fixedly connected between the upper shell 1 and the pin 3, used for connecting the pin 3 and the upper shell 1. The connecting sleeves 4 are fixedly connected between the ends of the lower shell 2. The upper shell 1 and the lower shell 2 are fixedly connected with the circuit board 6. The end of the pin 3 away from the upper shell 1 extends to the inside of the lower shell 2 through the connecting plate 8 and the circuit board 6. The connecting sleeve 4 and the connecting plate 8 are made of insulating rubber. When assembling the pin 3, the connecting sleeve 4 is sleeved on the outside of the pin 3, and then the connecting sleeve 4 is inserted into the corresponding mounting hole 5. The connecting sleeve 4 and the connecting plate 8 are integrally formed. The connecting sleeve 4 can realize the functions of fixing, sealing and insulating the pin 3, and is convenient for assembling, reduces the processing difficulty, and effectively reduces the processing cost.

[0028] The upper shell 1 and the lower shell 2 are circular and are made of metal. The use of all-metal materials ensures the mechanical properties of the sensor, shields the internal circuit, and improves EMC anti-interference capabilities.

[0029] A sealed cavity 11 is formed between the upper housing 1 and the circuit board 6. Filler 9, made of hard epoxy adhesive, is located within this cavity. The presence of this sealed cavity 11 and the hard epoxy adhesive further enhances the securing and sealing of the pins 3 and circuit board 6 after the adhesive cures.

[0030] The edge of the circuit board 6 is provided with a glue injection port 13 and an exhaust port 14. By providing the glue injection port 13, glue can be injected into the sealing cavity 11 during assembly, and the exhaust port 14 is provided on the through hole to discharge the gas inside the sealing cavity 11 during glue injection, thereby improving the sealing performance.

[0031] An ASIC chip 7 is fixedly connected to the side of the circuit board 6 facing the upper shell 1, and a MEMS chip 10 is fixedly connected to the side of the circuit board 6 facing the lower shell 1. A pressure inlet hole 12 is defined at the axis of the lower shell 2. Both the ASIC chip 7 and the MEMS chip 10 are positioned along an axis offset from the pressure inlet hole 12. By positioning the ASIC chip 7 and the MEMS chip 10 along an axis offset from the pressure inlet hole 12, they are positioned away from the pressure inlet hole 12, effectively mitigating damage to the ASIC chip 7 and the MEMS chip 10 from pressure pulses and extending the sensor's service life.

[0032] The upper shell 1 and the lower shell 2 are sealed by laser welding or glue. Sealing the upper shell 1 and the lower shell 2 by welding or gluing can reduce the processing difficulty and eliminate the need for post-processing, thereby reducing production costs.

[0033] Working principle: the pin 3 is assembled, the connecting sleeve 4 is sleeved on the outside of the pin 3, then the connecting sleeve 4 is inserted into the corresponding position of the mounting hole 5, wherein the connecting sleeve 4 and the connecting plate 8 are integrally formed, the connecting sleeve 4 can realize the functions of fixing, sealing and insulating the pin 3, and the assembly is convenient, the processing difficulty is reduced, and the processing cost is effectively reduced; the upper shell 1 and the lower shell 2 are made of full metal material, which guarantees the mechanical properties of the sensor, shields the internal circuit, improves the EMC anti-interference ability; by setting the sealing cavity 11 and the filler 9 made of hard epoxy glue, the fixing and sealing functions of the pin 3 and the circuit board 6 can be further strengthened after the glue is cured; by setting the glue injection port 13, the glue can be injected into the sealing cavity 11 when the assembly is convenient, the through hole is provided with the exhaust port 14, the gas in the sealing cavity 11 can be discharged when the glue is injected, and the sealing property is improved; by setting the ASIC chip 7 and the MEMS chip 10 along the axis deviating from the pressing hole 12, the ASIC chip 7 and the MEMS chip 10 can be away from the pressing hole 12, the damage of the pressure pulse to the ASIC chip 7 and the MEMS chip 10 is effectively relieved, and the service life of the sensor is prolonged; the upper shell 1 and the lower shell 2 are sealed by welding or glue, the processing difficulty can be reduced, and the post-processing is not needed, and the production cost is reduced.

[0034] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A full metal shell pressure sensor, characterized by: The utility model comprises an upper shell (1) and a lower shell (2), wherein the outer wall of the upper shell (1) is provided with a plurality of mounting holes (5), the interior of the mounting holes (5) is provided with plug pins (3), a connecting sleeve (4) is fixedly connected between the upper shell (1) and the plug pins (3), a connecting plate (8) is fixedly connected between the ends of the plurality of connecting sleeves (4) facing the lower shell (2), a circuit board (6) is fixedly connected between the upper shell (1) and the lower shell (2), and the end of the plug pin (3) away from the upper shell (1) passes through the connecting plate (8) and the circuit board (6) and extends to the interior of the lower shell (2).

2. The full metal shell pressure sensor according to claim 1, characterized in that: The connecting sleeve (4) and the connecting plate (8) are both made of insulating rubber.

3. The full metal shell pressure sensor according to claim 1, characterized in that: The upper shell (1) and the lower shell (2) are arranged in a circular shape, and both the upper shell (1) and the lower shell (2) are made of metal material.

4. The full metal shell pressure sensor according to claim 1, characterized in that: A sealed cavity (11) is enclosed between the upper shell (1) and the circuit board (6), and a filler (9) is provided inside the sealed cavity (11).

5. The full metal shell pressure sensor according to claim 4, characterized in that: The filler (9) is made of hard epoxy glue.

6. The full metal shell pressure sensor according to claim 1, characterized in that: A glue injection port (13) and an exhaust port (14) are provided on the edge of the circuit board (6).

7. The full metal shell pressure sensor according to claim 1, characterized in that: An ASIC chip (7) is fixedly connected to the side of the circuit board (6) facing the upper shell (1), and a MEMS chip (10) is fixedly connected to the side of the circuit board (6) facing the lower shell (1).

8. The full metal shell pressure sensor according to claim 7, characterized in that: A pressure inlet hole (12) is provided at the axis center of the lower shell (2).

9. The full metal shell pressure sensor according to claim 8, characterized in that: The ASIC chip (7) and the MEMS chip (10) are both arranged along an axis deviating from the pressure inlet hole (12).

10. The full metal shell pressure sensor according to claim 1, characterized in that: The upper shell (1) and the lower shell (2) are sealed by laser welding or bonding with glue.

Images