Ultrasonic sensor device and manufacturing method thereof

Abstract

An ultrasonic sensing device includes an outer shell, a piezoelectric component, a plate, and a plurality of fixing members. The outer shell includes a top wall, a bottom wall, and a surrounding side wall connected between the bottom wall and the top wall, and the top wall has an opening relative to the bottom wall at the connection with the surrounding side wall. The piezoelectric component includes a packaging body and a piezoelectric sheet at least partially covered by the packaging body, the packaging body is arranged on the bottom wall and surrounded by the surrounding side wall, and the piezoelectric sheet has a sensing surface exposed to the packaging body and facing the bottom wall. The plate is arranged on the top wall of the outer shell and has a pressing surface facing the packaging body and the top wall. A plurality of fixing members are used to fix the plate to the top wall of the outer shell so that the plate applies pressure to the packaging body of the piezoelectric component, thereby pressing the sensing surface of the piezoelectric sheet down to the bottom wall. The present invention also discloses a method for manufacturing an ultrasonic sensing device.

Description

Technical Field

[0001] The present invention relates to a sensing device, in particular to an ultrasonic sensing device with a piezoelectric component and a manufacturing method thereof. Background Art

[0002] Diesel engines require a selective catalytic reduction (SCR) system to reduce toxic nitrogen hydride (NOx) emissions. SCR uses urea added to diesel fuel to neutralize the toxic NOx, converting it into water and nitrogen. If the urea concentration in the diesel fuel is insufficient, the diesel engine may emit excessive NOx.

[0003] Urea used in diesel engines is mixed with water and stored in a storage tank adjacent to the diesel engine. Typically, multiple ultrasonic sensing devices are installed next to the storage tank to sense the urea concentration or liquid level of the fluid in the storage tank.

[0004] Conventional ultrasonic sensor devices mainly include a housing and a piezoelectric chip placed in the housing. To make the piezoelectric chip adhere to the sensing surface of the housing, a packaging colloid must be poured into the housing after the piezoelectric chip is placed in the housing.

[0005] However, the adhesive force of the encapsulant is sometimes insufficient to allow the piezoelectric piece to adhere tightly to the sensing surface, causing reliability issues in conventional ultrasonic sensor devices.

[0006] Furthermore, the process of pouring the encapsulating colloid into the outer shell often fails to precisely control the amount of colloid material used, resulting in material waste. Furthermore, it is difficult to perform quality control or rework on the piezoelectric chip and colloid within the outer shell. Summary of the Invention

[0007] The present invention provides an ultrasonic sensor device with high reliability.

[0008] The present invention provides a method for manufacturing an ultrasonic sensor device, which facilitates quality control and rework of a piezoelectric component and can reduce material costs in the manufacturing process.

[0009] The ultrasonic sensing device provided by the present invention includes an outer shell, a piezoelectric component, a plate and a plurality of fixing parts. The outer shell includes a top wall, a bottom wall and a surrounding side wall connected between the bottom wall and the top wall, and the top wall has an opening relative to the bottom wall at the connection with the surrounding side wall. The piezoelectric component includes a packaging body and a piezoelectric sheet at least partially covered by the packaging body, the packaging body is arranged on the bottom wall and surrounded by the surrounding side wall, and the piezoelectric sheet has a sensing surface exposed to the packaging body and facing the bottom wall. The plate is arranged on the top wall of the outer shell and has a pressing surface facing the packaging body and the top wall. A plurality of fixing parts are used to fix the plate to the top wall of the outer shell so that the plate applies pressure to the packaging body of the piezoelectric component, thereby pressing the sensing surface of the piezoelectric sheet down to the bottom wall.

[0010] A method for manufacturing an ultrasonic sensor device provided in one embodiment of the present invention includes the following steps:

[0011] a. Provide the aforementioned housing cover.

[0012] b. Provide a piezoelectric sheet and place it on the bottom wall through the opening in the top wall.

[0013] c. Pour liquid colloid into the opening.

[0014] d. Cover the plate on the top wall of the aforementioned outer shell.

[0015] e. Fix the plate to the top wall through multiple fixing parts, so that the plate applies pressure to the colloid, thereby pressing the piezoelectric piece down to the bottom wall.

[0016] Another embodiment of the present invention provides a method for manufacturing an ultrasonic sensor device, comprising the following steps:

[0017] a. Provide the aforementioned housing cover.

[0018] b. Provide the aforementioned piezoelectric component.

[0019] c. Place the piezoelectric component on the bottom wall through the opening with the sensing surface facing the bottom wall.

[0020] d. Cover the plate on the top wall of the aforementioned outer shell.

[0021] e. Fix the plate to the top wall through multiple fixing parts, so that the plate applies pressure to the package of the piezoelectric component, thereby pressing the sensing surface of the piezoelectric piece downward to the bottom wall.

[0022] In one embodiment of the present invention, the plate is in a bent shape or a flat plate shape.

[0023] In one embodiment of the present invention, the board is a circuit board.

[0024] In one embodiment of the present invention, the plate includes a plate having a single material or a plate having a composite material.

[0025] In one embodiment of the present invention, the piezoelectric component further includes a positive guide pin having one end connected to the piezoelectric sheet and a negative guide pin having one end connected to the piezoelectric sheet. The positive guide pin and the negative guide pin pass through the packaging body, and the plate body has two openings for the positive guide pin and the negative guide pin to pass through.

[0026] In one embodiment of the present invention, the package body is adhered to the surrounding sidewalls.

[0027] In one embodiment of the present invention, the package body has a surrounding shape that conforms to the surrounding sidewalls.

[0028] In one embodiment of the present invention, the piezoelectric component further includes a matching layer or a conductive layer disposed on the sensing surface of the piezoelectric piece and corresponding to the vibration energy of the piezoelectric piece.

[0029] In one embodiment of the present invention, each fixing member is a screw, the plate has a plurality of through holes, and the top wall has a plurality of screw holes.

[0030] In one embodiment of the present invention, the outer frame further includes an outer frame and a cover. The outer frame surrounds and connects the top wall and surrounding side walls of the outer cover and extends away from the bottom wall. An end away from the bottom wall has an opening, and the cover closes the opening.

[0031] In one embodiment of the present invention, the device further includes a reflective plate and a plurality of connecting rods. The reflective plate is disposed opposite to the outer cover and the outer frame, and each connecting rod is connected between the reflective plate and the outer frame.

[0032] In one embodiment of the present invention, the package includes a matching layer and / or an absorption layer corresponding to the vibration energy of the piezoelectric piece.

[0033] In the ultrasonic sensing device of the embodiment of the present invention, a plate is used to apply pressure to the package body, thereby pressing the piezoelectric plate downward against the bottom wall of the outer shell. Compared with the conventional technology in which the piezoelectric plate is connected to the outer shell only by a colloid, the piezoelectric plate in the embodiment of the present invention can be more tightly arranged on the bottom wall of the outer shell, thereby having higher reliability.

[0034] In the method for manufacturing an ultrasonic sensor device according to an embodiment of the present invention, the package and the piezoelectric chip are integrated into a module before being placed in the housing. The raw materials for the package can be poured into a dedicated mold to facilitate quality control and rework, and the amount of material required for pouring can be precisely controlled to avoid unnecessary material waste.

[0035] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, which can be implemented in accordance with the contents of the specification, and to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites preferred embodiments and describes them in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1A FIG. 1 is a schematic diagram of an explosion of an ultrasonic sensor device according to an embodiment of the present invention.

[0037] Figure 1B FIG. 4 is a cross-sectional schematic diagram of an ultrasonic sensor device according to an embodiment of the present invention.

[0038] Figure 1C FIG. 4 is a schematic diagram of a plate according to another embodiment of the present invention.

[0039] Figures 2A to 2D FIG. 4 is a schematic diagram of a manufacturing method of an ultrasonic sensor device according to another embodiment of the present invention.

[0040] Figure 3 FIG. 4 is a cross-sectional schematic diagram of an ultrasonic sensor device according to another embodiment of the present invention.

[0041] Figure 4 FIG. 4 is a schematic diagram of an ultrasonic sensing device according to another embodiment of the present invention. DETAILED DESCRIPTION

[0042] Figure 1A This is a schematic diagram of an explosion of an ultrasonic sensor device according to an embodiment of the present invention. Figure 1B This is a cross-sectional diagram of an ultrasonic sensor device according to an embodiment of the present invention. Figure 1A and Figure 1B The ultrasonic sensing device 100 of this embodiment includes a housing 110, a piezoelectric assembly 120, a plate 130, and a plurality of fixing members 140. The housing 110 includes a top wall 111, a bottom wall 112, and a surrounding sidewall 113 connected between the bottom wall 112 and the top wall 111. The top wall 111 has an opening 1110 facing the bottom wall 112 at the location where the surrounding sidewall 113 connects. The piezoelectric assembly 120 includes a package body 121 and a piezoelectric chip 122 at least partially encapsulated by the package body 121. The package body 121 is disposed on the bottom wall 112 and surrounded by the surrounding sidewall 113. The piezoelectric chip 122 has a sensing surface 1221 exposed from the package body 121 and facing the bottom wall 112. The plate 130 is disposed on the top wall 111 of the housing 110 and has a pressing surface 131 facing the package body 121 and the top wall 111. The plurality of fixing members 140 are used to fix the plate 130 to the top wall 111 of the outer shell 110 , and to press the plate 130 against the package 121 of the piezoelectric component 120 , thereby pressing the sensing surface 1221 of the piezoelectric piece 122 downward against the bottom wall 112 .

[0043] In this embodiment, the board 130 may include a board made of a single material or a composite material. In this embodiment, the board 130 may be a circuit board. For example, the board 130 may further include a mounting surface 132 opposite the pressing surface 131. The board 130 may be provided with a connector 133 on the mounting surface 132 for electrical connection to an external device (not shown).

[0044] In this embodiment, the plate 130 is in the shape of a flat plate, but is not limited thereto. Figure 1C A curved plate 130a is shown. One side of the plate 130a has a recess 134, and the other side has a corresponding protrusion 135. When the package body 121 protrudes from the opening 1110 of the top wall 111, it abuts against the recess 134. However, when the package body 121 is recessed into the opening 1110 of the top wall 111, it abuts against the protrusion 135.

[0045] In this embodiment, the package body 121 and the piezoelectric sheet 122 of the piezoelectric component 120 may be pre-assembled in a mold. Therefore, the manufacturing method of the ultrasonic sensor device 100 of this embodiment may include the following steps:

[0046] a. Provide a housing 110. b. Provide a piezoelectric assembly 120. c. Place the piezoelectric assembly 120 on the bottom wall 111 of the housing 110. d. Place the plate 130 on the top wall 111. e. Secure the plate 130 to the top wall 111 using the fasteners 140.

[0047] In this embodiment, the package body 121 of the piezoelectric component 120 has a surrounding shape conforming to the surrounding sidewall 113, for example Figure 1A The package body 121 and the surrounding sidewall 113 may also have other conformal shapes, such as polygons. The package body 121 may include a matching layer and / or an absorption layer corresponding to the vibration energy of the piezoelectric element. The material may include epoxy, silicon oxide (SiOx), or other colloids.

[0048] In this embodiment, the piezoelectric component 120 further includes an adhesive layer 125 disposed on the sensing surface 1221 of the piezoelectric sheet 122 and corresponding to the piezoelectric sheet 122 . The adhesive layer 125 may be a matching layer or a conductive layer corresponding to the vibration energy of the piezoelectric sheet 122 .

[0049] In this embodiment, the piezoelectric assembly 120 further includes a positive guide pin 123 connected at one end to the piezoelectric sheet 122 and a negative guide pin 124 connected at one end to the piezoelectric sheet 122. The positive guide pin 123 and the negative guide pin 124 extend through the package 121. The plate 130 has an opening 137 and an opening 138, respectively, through which the positive guide pin 123 and the negative guide pin 124 pass. The positive guide pin 123 and the negative guide pin 124 can be connected to an external power supply (not shown).

[0050] In this embodiment, each fixing member 140 is a screw. The plate 130 has a plurality of through-holes 136, and the top wall 111 of the outer cover 110 has a plurality of screw holes 1111. By locking these fixing members 140 into the screw holes 1111, the plate 130 is fixed to the top wall 111 and applies pressure to the package body 121. The number of fixing members 140 is at least three to balance the downward pressure on the plate 130.

[0051] In this embodiment, the outer shell 110 may be made of metal such as stainless steel, aluminum alloy or other alloys, but is not limited thereto. The outer shell 110 may also be made of insulating material such as polyamide (PA), polyethylene (PE) or polypropylene (PP).

[0052] The ultrasonic sensor device 100 of this embodiment can be placed in liquid, for example, and can be used in conjunction with a waveguide (not shown) to sense the height of the liquid, or can be placed opposite a reflector to sense the concentration of the liquid.

[0053] In the ultrasonic sensing device 100 of this embodiment, the plate 130 applies pressure to the package body 121, thereby allowing the piezoelectric chip 122 to abut against the bottom wall 111 of the outer shell 110. Compared to the conventional technology in which the piezoelectric chip is only connected to the outer shell by colloid, the piezoelectric chip 122 in the embodiment of the present invention can be more tightly attached to the bottom wall 111 of the outer shell 110, thereby having better reliability.

[0054] The ultrasonic sensor device 100 of this embodiment is manufactured by integrating the package 121 and the piezoelectric chip 122 into a module before being placed in the outer housing 110. The raw materials of the package 121 can be poured into a dedicated mold to facilitate quality control and rework, and the amount of material required for pouring can be precisely controlled to avoid unnecessary material waste.

[0055] Figures 2A to 2D FIG2 is a schematic diagram of a method for manufacturing an ultrasonic sensor device according to another embodiment of the present invention. The method for manufacturing the ultrasonic sensor device 100a of this embodiment is as follows.

[0056] First, please refer to Figure 2A , provide Figure 1A The outer shell 110 is then covered with a glue layer 125 on the bottom wall 112 of the outer shell 110. The piezoelectric piece 122 is then placed into the outer shell 110 through the opening 1110 of the top wall 111 and placed on the bottom wall 111. The glue layer 125 can provide preliminary positioning for the piezoelectric piece 122.

[0057] Please refer to Figure 2B , pouring liquid colloid 121a into the opening 1110 to cover the piezoelectric piece 122, the colloid 121a can be Figure 1AThe state of the package body 121 before curing.

[0058] Please refer to Figure 2C , provide Figure 1A The plate 130 is formed and covered on the top wall 111 of the outer shell 110. The plate 130 can be installed before or after the adhesive 121a is cured as required.

[0059] Please refer to Figure 2D The plate 130 is fixed to the top wall 111 by the fixing member 140, so that the plate 130 applies pressure to the colloid 121a, thereby pressing the sensing surface 1221 of the piezoelectric piece 122 downward to the bottom wall 112. When the colloid 121a solidifies as Figure 1A After the package body 121 is formed, the ultrasonic sensor device 100a of this embodiment is completed.

[0060] The ultrasonic sensor device 100a of this embodiment is Figure 1A The ultrasonic sensor device 100 is substantially the same as that of the embodiment, except that the package body 121 of this embodiment is cured in the outer shell 110 , so that the package body 121 adheres to the side wall 113 of the outer shell 110 .

[0061] Figure 3 This is a cross-sectional diagram of an ultrasonic sensor device according to another embodiment of the present invention. Figure 3 The ultrasonic sensor device 100b of this embodiment is Figure 1A The ultrasonic sensor device 100b of this embodiment is substantially similar to the ultrasonic sensor device 100 of FIG. The difference is that the ultrasonic sensor device 100b of this embodiment further includes an outer frame 150 and a cover 160. The outer frame 150 surrounds and connects the top wall 111 and surrounding side walls 113 of the outer housing 110, extending away from the bottom wall 112. It has an opening 1500 at one end away from the bottom wall 112. The cover 160 closes the opening 1500. The cover 160 and the outer frame 150 can be joined in various ways, such as adhesive bonding, snap fastening, or screw fastening, depending on the needs.

[0062] Figure 4 This is an exploded diagram of an ultrasonic sensor device according to another embodiment of the present invention. Figure 4 The ultrasonic sensor device 100c of this embodiment is Figure 3 The ultrasonic sensing device 100c of this embodiment is substantially similar to the ultrasonic sensing device 100b, except that it further includes a reflector 170 and a plurality of connecting rods 180. The reflector 170 is disposed opposite the outer cover 110 and the outer frame 150, while the connecting rods 180 are connected between the reflector 170 and the outer frame 150. The reflector 170 is used to reflect the vibration signal of the piezoelectric element 120 to sense the concentration of the liquid.

[0063] In the ultrasonic sensing device of the embodiment of the present invention, a plate is used to apply pressure to the package body, thereby pressing the piezoelectric plate downward against the bottom wall of the outer shell. Compared with the conventional technology in which the piezoelectric plate is connected to the outer shell only by a colloid, the piezoelectric plate in the embodiment of the present invention can be more tightly arranged on the bottom wall of the outer shell, thereby having higher reliability.

[0064] The ultrasonic sensor device of an embodiment of the present invention is manufactured by integrating the package and the piezoelectric chip into a module before being placed in the housing. The raw materials of the package can be poured into a dedicated mold to facilitate quality control and rework, and the amount of material required for pouring can be precisely controlled to avoid unnecessary material waste.

[0065] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the present profession can make slight changes or modifications to equivalent embodiments of equivalent changes using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An ultrasonic sensor device, characterized in that: include: An outer shell, comprising a top wall, a bottom wall, and a surrounding side wall connected between the bottom wall and the top wall, wherein the top wall has an opening facing the bottom wall at a location where the surrounding side wall is connected; A piezoelectric component comprising a package body and a piezoelectric sheet at least partially encapsulated by the package body, the package body being disposed on the bottom wall and surrounded by the surrounding sidewall, the piezoelectric sheet having a sensing surface exposed from the package body and facing the bottom wall, the package body and the piezoelectric sheet being cast into a mold to form a module before being placed in the outer cover; a plate body, disposed on the top wall of the outer shell and having a pressing surface facing the packaging body and the top wall; A plurality of fixing members are used to fix the plate to the top wall of the outer shell, so that the plate applies pressure to the package of the piezoelectric component, thereby pressing the sensing surface of the piezoelectric piece downwardly against the bottom wall; The pressing surface of the plate is arranged to correspond to the upper surface of the packaging body so that the pressing surface cooperates with and presses against the upper surface of the packaging body.

2. The ultrasonic sensor device according to claim 1, wherein The plate body is in a bent shape or a flat plate shape.

3. The ultrasonic sensor device according to claim 1, wherein The board body is a circuit board.

4. The ultrasonic sensor device according to claim 1, wherein The plate body includes a plate body having a single material or a plate body having a composite material.

5. The ultrasonic sensor device according to claim 1, wherein: The piezoelectric component further includes a positive guide pin connected to the piezoelectric sheet at one end and a negative guide pin connected to the piezoelectric sheet at one end. The positive guide pin and the negative guide pin pass through the package body, and the plate body has two openings for the positive guide pin and the negative guide pin to pass through.

6. The ultrasonic sensor device according to claim 1, wherein: The package body is adhered to the surrounding side wall.

7. The ultrasonic sensor device according to claim 1, wherein: The package body has a surrounding shape that conforms to the surrounding sidewall.

8. The ultrasonic sensor device according to claim 1, wherein: The piezoelectric component further includes a matching layer or a conductive layer disposed on the sensing surface of the piezoelectric piece and corresponding to the vibration energy of the piezoelectric piece.

9. The ultrasonic sensor device according to claim 1, wherein: Each of the fixing members is a screw, the plate body has a plurality of through holes, and the top wall has a plurality of screw holes.

10. The ultrasonic sensor device according to claim 1, wherein The ultrasonic sensor device further includes an outer frame and a cover. The outer frame surrounds and connects the top wall and the surrounding side wall of the outer cover and extends away from the bottom wall. An end away from the bottom wall has an opening, and the cover closes the opening.

11. The ultrasonic sensor device according to claim 10, wherein: The ultrasonic sensor device further includes a reflective plate and a plurality of connecting rods. The reflective plate is disposed opposite to the outer cover and the outer frame, and each of the connecting rods is connected between the reflective plate and the outer frame.

12. The ultrasonic sensor device according to claim 1, wherein The package includes a matching layer and / or an absorption layer corresponding to the vibration energy of the piezoelectric piece.

13. A method for manufacturing an ultrasonic sensor device, characterized in that: The following steps are involved: A housing cover is provided, the housing cover comprising a top wall, a bottom wall, and a surrounding side wall connected between the top wall and the bottom wall, wherein the top wall has an opening facing the bottom wall at a location where the top wall is connected to the surrounding side wall; A piezoelectric component is provided, comprising a package body and a piezoelectric sheet at least partially covered by the package body, the piezoelectric sheet having a sensing surface exposed from the package body, the package body and the piezoelectric sheet being cast in a mold to form a module; placing the piezoelectric component on the bottom wall through the opening with the sensing surface facing the bottom wall; Covering the top wall of the outer shell with a plate, wherein the plate has a pressing surface facing the packaging body and the top wall; as well as The plate is fixed to the top wall by a plurality of fixing members, so that the plate applies pressure to the package of the piezoelectric component, thereby pressing the sensing surface of the piezoelectric sheet downwards to the bottom wall; The pressing surface of the plate is arranged to correspond to the upper surface of the packaging body so that the pressing surface cooperates with and presses against the upper surface of the packaging body.

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