A pressure sensor and a method for manufacturing the same

Abstract

The present invention discloses a pressure sensor, including a base component, a first guide needle, a second guide needle, a diaphragm and a chip, wherein the base component is fixedly connected to the diaphragm, the base component is fixedly connected to the chip, the first guide needle, the second guide needle are fixedly connected to the base component, the first guide needle is electrically connected to the chip, and also includes a cover component, wherein the cover component is at least partially located between the diaphragm and the chip, the cover component includes a cover body and a metal part, the cover body is formed integrally with the metal part by sintering or injection molding of a non-metallic material, and the metal part is welded and fixed to the second guide needle. The cover body of the present application is formed integrally with the metal part by sintering or injection molding, and the metal part is welded and fixed to the guide needle component, which improves the reliability of the installation of the cover body component compared to the background technology.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a pressure sensor and a manufacturing method thereof. Background Art

[0002] The pressure sensor is an important component for collecting pressure signals in the control system. Its working principle is to convert the pressure signal of the measured fluid into an electrical signal, and then process the electrical signal. The processed electrical signal is used as the output signal of the pressure sensor to realize system operation control.

[0003] Figure 4 FIG. 1 is a schematic diagram of the structure of a pressure sensor of the background technology. Figure 4 As shown, the base 01 is fixedly connected to the tube seat 02, the diaphragm 06 is fixedly connected to the base 01, the ceramic cover 03 is bonded to the tube seat 02 by glue, the ceramic cover 03 and the tube seat 02 form a cavity 04, the cavity 04 is filled with silicone oil, the pressure chip 07 is located in the cavity 04, and the pressure chip 07 is connected to the pin 05 by aluminum wire. In the pressure sensor of this structure, the ceramic cover 03 is bonded to the tube seat 02 by glue. After the pressure sensor is used for a period of time, there is a risk of failure of the glue, which will affect the reliability of the installation of the ceramic cover 03.

[0004] In view of this, how to improve the fixing reliability of the ceramic cover is a problem that needs to be solved by those skilled in the art. Summary of the invention

[0005] To achieve the above-mentioned purpose, the present application provides a pressure sensor, including a base component, a first guide needle, a second guide needle, a diaphragm and a chip, the base component is fixedly connected to the diaphragm, the base component is fixedly connected to the chip, the first guide needle, the second guide needle are fixedly connected to the base component, the first guide needle is electrically connected to the chip, and also includes a cover body component, the cover body component is at least partially located between the diaphragm and the chip, the cover body component includes a cover body and a metal part, the cover body is made of non-metallic material and is integrally formed with the metal part by sintering or injection molding, and the metal part is welded and fixed to the second guide needle.

[0006] In the pressure sensor provided by the present application, the second guide pin is fixedly connected to the base component, the cover component includes a cover body and a metal part, the cover body is formed integrally with the metal part by sintering or injection molding of a non-metallic material, and the metal part is fixed to the second guide pin by welding. Compared with the background technology, the reliability of the cover component installation is improved.

[0007] The present application also provides a method for manufacturing a pressure sensor having the above technical effects, comprising:

[0008] Step 10: Prepare a first guide needle, a second guide needle, a diaphragm and a chip, wherein the first guide needle and the second guide needle are fixed to the base component by glass sintering; prepare a cover body component, wherein the cover body component includes a cover body and a metal part, wherein the cover body is formed integrally with the metal part by sintering or injection molding of a non-metallic material; Step 20: Bond the chip to the base component, wherein the chip is electrically connected to the first guide needle, install the cover body component into the accommodating cavity of the base component, and fix the metal part to the second guide needle by welding; Step 30: fix the base component to the diaphragm by welding; Step 40: inject oil into the accommodating cavity to seal the accommodating cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram of a partial structure of a pressure sensor disclosed in an embodiment of the present invention;

[0010] Figure 2 for Figure 1 The enlarged schematic diagram of point I in the middle;

[0011] Figure 3a , Figure 3b for Figure 1 Three-dimensional images of the middle cover body parts in different directions;

[0012] Figure 4 The figure is a schematic structural diagram of a pressure sensor according to the background technology.

[0013] In the figure:

[0014] 1-base component, 10-accommodating chamber;

[0015] 11-base, 110-inner cavity of the base, 111-inner peripheral wall of the base;

[0016] 112- oil filling hole, 12- glass seat, 121- wall surface;

[0017] 2-hood parts;

[0018] 200 - inner cavity of the cover body component, 201 - operation hole, 202 - side hole, 203 - second through hole;

[0019] 21-cover body, 22-metal part, 221-top, 2211-inner surface;

[0020] 23-plate body, 231-first through hole, 232-long hole, 24-outer peripheral wall of the cover body component;

[0021] 31-first guide needle, 32-second guide needle, 321-end;

[0022] 4-diaphragm, 5-chip, 6-pressing part, 7-sealing part, 8-metal wire, 9-solder. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] In this article, terms such as "upper, lower, inside, outside" are established based on the positional relationship shown in the drawings. Depending on the different orientations of the products shown in the drawings, the corresponding directions and positional relationships may also change accordingly. Therefore, they cannot be understood as absolute limitations on the scope of protection.

[0025] Figure 1 A schematic diagram of a partial structure of a pressure sensor disclosed in an embodiment of the present invention; Figure 2 for Figure 1 The enlarged schematic diagram of point I in the middle; Figure 3a , Figure 3b for Figure 1 Three-dimensional images of the middle cover body parts from different directions.

[0026] Please refer to Figure 1 , Figure 2 , Figure 3a , Figure 3b As shown, the pressure sensor provided in this embodiment mainly includes a base component 1, a cover component 2, a first guide needle 31, a second guide needle 32, a diaphragm 4, a chip 5, a pressing member 6 and a blocking member 7. The base component 1 includes a base 11 and a glass seat 12. The glass seat 12 is formed in the inner cavity 110 of the base 11 by glass sintering or injection molding. During the glass sintering or injection molding process, the first guide needle 31 and the second guide needle 32 are embedded in the glass seat 12, that is, after sintering or injection molding cooling, the first guide needle 31 and the second guide needle 32 are inserted into the glass seat 12. The periphery of the diaphragm 4 is fixed at the lower port of the base 11 by the pressing member 6 and welded and sealed. The base component 1, the diaphragm 4 and the sealing component 7 constitute a sealed space, the clamping component 6 is provided with a connecting hole, the sealed space is filled with oil (not shown), the base 11 is provided with an oil filling hole 112, and the sealing component 7 is arranged at the outer port of the oil filling hole 112 so as to seal the oil filling hole 112 after the oil filling is completed. The sealing component 7 can be fixed by welding or the like.

[0027] When in use, the fluid medium enters the space between the diaphragm 4 and the clamping piece 6 through the connecting hole of the clamping piece 6, transmits pressure to the diaphragm 4, and then transmits it to the chip 5 through the diaphragm 4 and the oil. After the chip 5 senses the pressure signal, it converts it into an electrical signal and transmits it to the outside through the metal wire 8 and the guide needle component 3.

[0028] Specifically, the glass seat 12 includes a wall surface 121 facing the diaphragm 4. The chip 5 is bonded and fixed to the wall surface 121 of the glass seat 12. The chip 5 is electrically connected to the first guide pin 31. The base component 1 includes a receiving cavity 10, which is connected to the aforementioned oil filling hole 112. The cover component 2 is located in the receiving cavity 10, and the outer peripheral wall 24 of the cover component 2 is gap-matched with the inner peripheral wall of the base component 1 (i.e., the inner peripheral wall 111 of the base 11) that forms the aforementioned receiving cavity 10. The cover component 2 is at least partially located between the diaphragm 4 and the chip 5, and can fill part of the receiving cavity 10 to reduce the amount of oil filled and ensure the sensitivity of the chip 5. Specifically, the cover body component 2 includes a cover body 21 and a metal part 22. The metal part 22 is made by stamping a metal material. The cover body 21 is formed by sintering a non-metallic material ceramic or glass and the metal part 22 as one piece. Of course, the cover body 21 can also be formed by injection molding a non-metallic material plastic and the metal part 22 as one piece. The metal part 22 is welded and fixed to the second guide needle 32.

[0029] In this embodiment, during the process of manufacturing the cover body 21 by sintering or injection molding, the second guide pin 32 is fixedly connected to the base component 1, the cover body 21 is sintered or injection molded on the metal member 22 to form an integrated structure, and the metal member 22 is welded and fixed to the second guide pin 32. In this way, compared with the background technology in which the ceramic cover is bonded to the tube seat, the reliability of the installation of the cover body component 2 is improved in this embodiment.

[0030] Furthermore, the cover body component 2 further includes a plate body 23, and the cover body 21 and the plate body 23 are integrally formed with the metal part 22 by sintering or injection molding. In this way, the plate body 23 does not need a bonding process, which can simplify the manufacturing process and improve production efficiency.

[0031] The second guide pin 32 is closer to the diaphragm 4 than the first guide pin 31. The first guide pin 31 is electrically connected to the chip 5 through the metal wire 8. Specifically, one end of the metal wire 8 is welded to the chip 5, and the other end of the metal wire 8 is welded to the first guide pin 31. The plate body 23 includes a first through hole 231 and an elongated hole 232 extending radially from the first through hole 231. The chip 5 is at least partially located in the first through hole 231, the first guide pin 31 is partially located in the elongated hole 232, and the metal wire 8 is partially located in the elongated hole 232.

[0032] The cover body part 2 includes an operation hole 201, a side hole 202 and a second through hole 203. The operation hole 201 and the second through hole 203 penetrate the cover body 21 and the metal part 22. For the convenience of welding, the end 321 of the second guide pin 32 close to the diaphragm 4 is aligned with the operation hole 201 in the axial direction of the pressure sensor during assembly. The second guide pin 32 is fixed to the metal part 22 by welding so that the solder 9 is filled between the end 321 of the second guide pin 32 and the operation hole 201. In this embodiment, the second guide pin 32 is an O-point guide pin. Such a setting ensures that the sensor outputs a pressure signal stably. The side hole 202 can connect the gap between the outer peripheral wall of the cover body part 2 and the inner peripheral wall of the base part 1 and the inner cavity 200 of the cover body part 2. The oil can be introduced into the inner cavity 200 of the cover body part 2 through the side hole 202. The second through hole 203 can introduce the oil between the cover body part 2 and the diaphragm 4.

[0033] Furthermore, the above-mentioned metal part 22 is roughly bowl-shaped, including a top 221, and the top 221 is at least partially located between the diaphragm 4 and the chip 5, which can improve the chip 5's ability to resist electrostatic interference; the inner surface 2211 of the top 221 facing the chip 5 is exposed, that is, it is not covered by the above-mentioned cover body 21, and the end 321 of the second guide needle 32 is in contact with the inner surface 2211 of the top 221, so that welding is convenient, and the welding quality can be improved, thereby ensuring the reliability of the electrical connection between the metal part 22 and the second guide needle 32.

[0034] Combine the following Figure 1 , Figure 2 , Figure 3a and Figure 3b A method for manufacturing the pressure sensor in the above-described embodiment will be described.

[0035] The manufacturing method comprises:

[0036] Step 10: Prepare the base component 1: the base component 1 includes a base 11 and a glass seat 12, the glass seat 12 is sealed and fixed to the base 11 by glass sintering, and the first guide needle 31 and the second guide needle 32 are embedded in the glass seat 12 by sintering; prepare the cover body component 2, the cover body component 2 is provided with an operation hole 201 and a side hole 202, the cover body component 2 includes a cover body 21 and a metal part 22, the metal part 22 is stamped by metal material, and the cover body 21 is integrally formed with the metal part 22 by ceramic or glass sintering, or plastic injection molding; prepare the diaphragm 4, the chip 5, the clamping part 6, and the blocking part 7.

[0037] Step 20: Bond the chip 5 to the base component 1, weld one end of the metal wire 8 to the chip 5, and weld the other end of the metal wire 8 to the first guide pin 31, so that the chip 5 is electrically connected to the first guide pin 31, install the cover body component 2 into the accommodating cavity 10 of the base component 1, make the outer peripheral wall 24 of the cover body component 2 and the inner peripheral wall 111 of the base 11 have a clearance fit, and weld the second guide pin 32 to the metal part 22 to fix it, so that the second guide pin 32 is electrically connected to the metal part 22 by welding.

[0038] Step 30: The pressing piece 6 is pressed against the periphery of the diaphragm 4 , and the base 11 , the diaphragm 4 , and the pressing piece 6 are welded and fixed, so that the diaphragm 4 covers the accommodating cavity 10 of the base component 1 and is sealed.

[0039] Step 40: Inject oil (not shown) into the accommodating cavity 10 of the base component 1 through the oil filling hole 112 of the base 11, and weld the sealing member 7 to the outer end of the oil filling hole 112 to seal the oil filling hole 112, that is, to seal the accommodating cavity 10 of the base component 1.

[0040] In this manufacturing method, the cover body part 2 is processed in one go by ceramic or glass sintering or plastic injection molding, and the metal part 22 of the cover body part 2 is welded and fixed to the second guide pin 32 fixed to the base part 1. In this embodiment, the cover body part 2 is fixed by welding, which is more reliable than the adhesive fixation in the background technology; at the same time, the curing time of the glue during the adhesive bonding is saved, and the production efficiency is improved.

[0041] Furthermore, in the above step 10, the cover body component 2 further includes a plate body 23, and the cover body 21 and the plate body 23 are integrally formed with the metal part 22 by ceramic or glass sintering or plastic injection molding. In this way, the plate body 23 does not need to be bonded to the base component 1, which can simplify the manufacturing process and improve production efficiency.

[0042] The above embodiments are only preferred solutions of the present invention, and are not limited thereto. On this basis, the design can be changed to obtain different implementation methods. For example, the chip 5 can also be installed on the glass seat 12 through a chip mounting component. Since there are many possible implementation methods, they will not be described one by one here.

[0043] The pressure sensor provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A pressure sensor, comprising a base component, a first guide needle, a second guide needle, a diaphragm and a chip, wherein the base component is fixedly connected to the diaphragm, the base component is fixedly connected to the chip, the first guide needle, the second guide needle are fixedly connected to the base component, and the first guide needle is electrically connected to the chip, characterized in that: It also includes a cover body component, which is at least partially located between the diaphragm and the chip. The cover body component includes a cover body and a metal part. The cover body is made of non-metallic material and is integrally formed with the metal part by sintering or injection molding. The metal part is welded and fixed to the second guide needle.

2. The pressure sensor according to claim 1, characterized in that: The cover body component also includes a plate body, and the cover body and the plate body are integrally formed with the metal part by sintering or injection molding.

3. The pressure sensor according to claim 2, characterized in that: The first guide needle is electrically connected to the chip through a metal wire, the plate body includes a first through hole and an elongated hole extending radially from the first through hole, the chip is at least partially located in the first through hole, the first guide needle is partially located in the elongated hole, and the metal wire is partially located in the elongated hole.

4. The pressure sensor according to claim 3, characterized in that: The cover member includes an operation hole. The second guide needle is closer to the diaphragm than the first guide needle. The end of the second guide needle close to the diaphragm corresponds to the operation hole in the axial direction of the pressure sensor. Solder is filled between the end and the operation hole.

5. The pressure sensor according to claim 4, characterized in that: The metal piece is substantially bowl-shaped and comprises a top portion, wherein the top portion is at least partially located between the diaphragm and the chip, an inner surface of the top portion facing the chip is exposed, and the end portion of the second guide needle contacts the inner surface of the top portion.

6. The pressure sensor according to any one of claims 1 to 5, characterized in that: The base component includes a base and a glass seat, the glass seat is formed in the inner cavity of the base by sintering glass, the first guide needle and the second guide needle are penetrated through the glass seat, and the chip is bonded to the wall of the glass seat facing the diaphragm.

7. The pressure sensor according to claim 6, characterized in that: The invention also includes a sealing member, wherein the base is provided with an oil filling hole, and the sealing member blocks the oil filling hole. The base member includes a accommodating cavity, and the accommodating cavity is communicated with the oil filling hole. The cover member is located in the accommodating cavity, and the outer peripheral wall of the cover member is gap-matched with the inner peripheral wall of the base member forming the accommodating cavity. The cover member includes a side hole, and the side hole can connect the gap between the outer peripheral wall of the cover member and the inner peripheral wall of the base member and the inner cavity of the cover member.

8. A method for manufacturing a pressure sensor, characterized in that: include: Step 10: preparing a first guide needle, a second guide needle, a membrane and a chip, wherein the first guide needle and the second guide needle are fixed to the base component by glass sintering; Prepare a cover body component, the cover body component includes a cover body and a metal part, the cover body is made of a non-metallic material and is integrally formed with the metal part by sintering or injection molding; Step 20: bonding the chip to the base component, electrically connecting the chip to the first guide pin, placing the cover component into the accommodating cavity of the base component, and fixing the metal part to the second guide pin by welding; Step 30: The base component is welded and fixed to the diaphragm; Step 40: injecting oil into the accommodating cavity to seal the accommodating cavity.

9. The method for manufacturing a pressure sensor according to claim 8, characterized in that: In the step 10, the cover body component also includes a plate body, and the cover body and the plate body are integrally formed with the metal part by sintering or injection molding to prepare a clamping part and a sealing part; in the step 30, the base component, the diaphragm and the clamping part are welded and fixed; in the step 40, the sealing part is used to seal the accommodating cavity.

10. The method for manufacturing a pressure sensor according to claim 8, characterized in that: The step 10 also includes: preparing a metal wire, the base component includes a base and a glass seat, the glass seat is fixed to the base by glass sintering, and the first guide needle and the second guide needle are embedded in the glass seat by glass sintering; in the step 20: welding one end of the metal wire to the chip, and welding the other end of the metal wire to the first guide needle.

11. The method for manufacturing a pressure sensor according to claim 8, characterized in that: In step 20: an operation hole is formed in the cover body component, and after the end of the second guide needle close to the diaphragm corresponds to the operation hole, the second guide needle is fixed to the metal component by welding.

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