Ultrasonic transducer structure
By using an adhesive layer to bond the positive electrode wire and the piezoelectric element in the ultrasonic transducer, the problem of piezoelectric characteristic attenuation caused by high temperature during the welding process is solved, thus improving the measurement accuracy and stability.
Patent Information
- Application Number
- CN202422957765.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-12-02
AI Technical Summary
In existing ultrasonic transducers, the high temperature during the welding of the positive electrode wire causes the piezoelectric properties of the piezoelectric ceramic to decay, affecting the measurement accuracy and stability.
The positive electrode and the piezoelectric element are connected by adhesive bonding to avoid the heat load of welding and improve the connection method to reduce the degradation of piezoelectric performance.
It improves the accuracy and stability of ultrasonic measurement and avoids the impact of welding heat load on piezoelectric materials.
Smart Images
Figure CN223642208U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of ultrasonic technology, and in particular to an ultrasonic transducer structure. Background Technology
[0002] An ultrasonic transducer is a device that converts electrical energy into mechanical vibration energy, commonly used in applications such as ultrasonic cleaning, welding, and flaw detection. In gas meters, ultrasonic transducers can be used to measure gas flow rate by emitting and receiving ultrasonic signals. The time difference of ultrasonic waves propagating through the gas can be used to calculate the gas velocity.
[0003] Generally speaking, the main components of existing ultrasonic transducers are piezoelectric ceramics, metal shells, and acoustic matching layers. The positive electrode is connected to the surface of the piezoelectric ceramics by soldering, and the negative electrode is connected to the metal shell by soldering or resistance welding.
[0004] Understandably, the Curie temperature of piezoelectric ceramics is generally around 300℃. When the ambient temperature exceeds the Curie temperature, the piezoelectric properties of the ceramics will completely disappear. However, even if the ambient temperature does not exceed the Curie temperature, the piezoelectric properties of the ceramics will gradually decrease as the ambient temperature approaches the Curie temperature. Generally, the melting point of lead-free solder wire is 220℃, while the soldering temperature of a conventional soldering iron exceeds 300℃. Thus, when the positive electrode wire is soldered, a momentary high temperature may directly act on the piezoelectric ceramic. This momentary high temperature causes the piezoelectric performance of the ceramic to decrease, which in turn leads to a reduction in the subsequent electrical signal, thereby affecting the accuracy of ultrasonic measurement. Utility Model Content
[0005] This application provides an ultrasonic transducer structure. To address the issue that the high temperatures generated during the welding process between the positive electrode and the piezoelectric element weaken the piezoelectric properties, the connection method between the piezoelectric element and the positive electrode is improved by bonding them with an adhesive layer. This avoids the influence of welding heat load, reduces the attenuation of the piezoelectric properties of the piezoelectric element, and thus improves the accuracy and stability of ultrasonic measurement.
[0006] This application provides an ultrasonic transducer structure, including:
[0007] A piezoelectric material having opposing first and second surfaces in a first direction;
[0008] The terminal block is located on one side of the first surface of the piezoelectric body, and the terminal block and the first surface of the piezoelectric body are connected by a first adhesive layer;
[0009] The metal housing, at least a portion of which is located on one side of the second surface of the piezoelectric element, is connected to the second surface of the piezoelectric element by a second adhesive layer.
[0010] The positive wire is fixedly connected to the terminal block.
[0011] The ultrasonic transducer structure provided in this application includes a piezoelectric element, a terminal block, a metal housing, and a positive electrode wire. The piezoelectric element has a first surface and a second surface facing each other in a first direction. The terminal block is located on one side of the first surface of the piezoelectric element and is connected to the first surface of the piezoelectric element via a first adhesive layer. At least a portion of the metal housing is located on one side of the second surface of the piezoelectric element and is connected to the second surface of the piezoelectric element via a second adhesive layer. The positive electrode wire is fixedly connected to the terminal block. Thus, to address the issue of the high temperature generated during the welding process between the positive electrode wire and the piezoelectric element weakening the piezoelectric properties, the connection method between the piezoelectric element and the positive electrode wire is improved by bonding them through an adhesive layer. This avoids the influence of welding heat load, reduces the attenuation of the piezoelectric properties of the piezoelectric element, and thereby improves the accuracy and stability of ultrasonic measurement.
[0012] In one possible implementation, the first adhesive layer and / or the second adhesive layer are conductive adhesive layers with conductive particles.
[0013] In one possible implementation, at least some of the terminals are flat plate structures, and the flat plate structure is connected to the first surface of the piezoelectric body through a first adhesive layer.
[0014] In one possible implementation, the positive wire and the terminal block are soldered or crimped together.
[0015] In one possible implementation, the area of the flat plate structure is greater than or equal to 8 mm². 2 .
[0016] In one possible implementation, the first adhesive layer and / or the second adhesive layer are non-conductive adhesive layers, and the thickness of the first adhesive layer and / or the second adhesive layer is less than or equal to 10 μm.
[0017] In one possible implementation, the ultrasonic transducer structure further includes a matching layer;
[0018] The matching layer is located on the side of the metal housing that faces away from the piezoelectric element, and the matching layer and the metal housing are connected by a third adhesive layer.
[0019] In one possible implementation, the wavelength of the matching layer is λ, and the thickness of the matching layer is equal to 1 / 4λ.
[0020] In one possible implementation, the ultrasonic transducer structure further includes: a negative electrode wire;
[0021] The negative electrode is located on one side of the metal casing, and the negative electrode is fixedly connected to the metal casing.
[0022] In one possible implementation, the ultrasonic transducer structure further includes a backing portion;
[0023] The metal housing has a receiving cavity for placing the piezoelectric element, with a backing portion located inside the receiving cavity and on one side of the piezoelectric element in the second direction.
[0024] In addition to the technical problems solved by this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions as described above, other technical problems that can be solved by the ultrasonic transducer structure provided by this application, other technical features contained in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific embodiments. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are only a part of the embodiments of this application. These drawings and text descriptions are not intended to limit the scope of the concept of this application in any way, but to illustrate the concept of this application to those skilled in the art by referring to specific embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 This is a top view of the ultrasonic transducer structure provided in an embodiment of this application;
[0027] Figure 2 for Figure 1 A cross-sectional schematic diagram of BB;
[0028] Figure 3 This is a schematic diagram of the ultrasonic transducer structure provided in the embodiment of this application, in which the positive electrode wire and the terminal are welded together.
[0029] Figure 4 This is a schematic diagram of the ultrasonic transducer structure provided in the embodiment of this application, in which the positive electrode wire and the terminal are crimped together.
[0030] Figure 5 This is a schematic diagram of the ultrasonic transducer structure provided in an embodiment of this application from another angle.
[0031] Explanation of reference numerals in the attached figures:
[0032] 100 - Structure of ultrasonic transducer;
[0033] 200 - Piezoelectric element; 210 - First surface; 220 - Second surface;
[0034] 300 - Terminal block; 310 - First adhesive layer;
[0035] 400 - Metal casing; 410 - Second adhesive layer; 420 - Receiving cavity;
[0036] 500 - Positive electrode line;
[0037] 600 - Matching layer; 610 - Third adhesive layer;
[0038] 700-Negative electrode line;
[0039] 800 - Backing section. Detailed Implementation
[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0041] As described in the background section, the Curie temperature of piezoelectric ceramics is generally around 300°C. When the ambient temperature exceeds the Curie temperature, the piezoelectric properties of the ceramics completely disappear. However, even if the ambient temperature does not exceed the Curie temperature, the piezoelectric properties of the ceramics will gradually decrease as the ambient temperature approaches the Curie temperature. Generally, the melting point of lead-free solder wire is 220°C, while the soldering temperature of a conventional soldering iron exceeds 300°C. Thus, when the positive electrode wire is soldered, a momentary high temperature may directly act on the piezoelectric ceramic. This momentary high temperature causes the piezoelectric performance of the ceramic to decrease, which in turn leads to a reduction in the subsequent electrical signal, thereby affecting the accuracy of ultrasonic measurement.
[0042] To address the aforementioned technical problems, this application provides an ultrasonic transducer. The ultrasonic transducer includes a piezoelectric element, a terminal block, a metal housing, and a positive electrode wire. The piezoelectric element has a first surface and a second surface facing each other in a first direction. The terminal block is located on one side of the first surface of the piezoelectric element and is connected to the first surface of the piezoelectric element via a first adhesive layer. At least a portion of the metal housing is located on one side of the second surface of the piezoelectric element and is connected to the second surface of the piezoelectric element via a second adhesive layer. The positive electrode wire is fixedly connected to the terminal block. Thus, to address the issue of the high temperature generated during the welding process between the positive electrode wire and the piezoelectric element weakening the piezoelectric properties, the connection method between the piezoelectric element and the positive electrode wire is improved by using adhesive bonding. This avoids the influence of welding heat load, reduces the attenuation of the piezoelectric properties of the piezoelectric element, and thereby improves the accuracy and stability of ultrasonic measurement.
[0043] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0044] This application provides an ultrasonic transducer structure. To address the issue of weakened piezoelectric properties due to the high temperatures generated during the welding process between the positive electrode and the piezoelectric element, the connection method between the piezoelectric element and the positive electrode is improved by bonding them with an adhesive layer. This avoids the influence of welding heat load, reduces the attenuation of the piezoelectric performance, and thus improves the accuracy and stability of ultrasonic measurement. The specific structure of the ultrasonic transducer provided in this application embodiment will be described below with reference to the accompanying drawings.
[0045] refer to Figure 1 This application provides an ultrasonic transducer structure 100. The ultrasonic transducer structure 100 may include a piezoelectric element 200, a terminal block 300, a metal housing 400, and a positive electrode wire 500. In one possible implementation, such as... Figure 2 As shown, the piezoelectric element 200 may have a first surface 210 and a second surface 220 in a first direction, wherein the first surface 210 and the second surface 220 are disposed opposite to each other. It is understood that the terminal 300 may be located on one side of the first surface 210 of the piezoelectric element 200, and the terminal 300 and the first surface 210 of the piezoelectric element 200 may be bonded together by a first adhesive layer 310. Correspondingly, at least a portion of the metal housing 400 may be located on one side of the second surface 220 of the piezoelectric element 200, and the metal housing 400 and the second surface 220 of the piezoelectric element 200 may be bonded together by a second adhesive layer 410. Additionally, the positive wire 500 may be fixedly connected to the terminal 300. In this way, by setting a terminal 300 between the positive electrode 500 and the piezoelectric body 200, and bonding the terminal 300 and the piezoelectric body 200 together with an adhesive layer, the thermal load caused by the direct contact between the positive electrode 500 and the piezoelectric body 200 is avoided, thereby preventing the attenuation of the piezoelectric performance of the piezoelectric body 200 and improving the accuracy and stability of ultrasonic measurement.
[0046] It is understood that, in one possible implementation, the terminal block 300 may be a terminal block 300 having a flat plane 320 structure. For example, as... Figure 4 As shown, the terminal block 300 can be a flat plate structure. (Referring to...) Figure 2 as well as Figure 3The positive electrode 500 can be first connected to the terminal block 300, thereby forming a single unit with the terminal block 300. This unit, formed by the positive electrode 500 and the terminal block 300, is then bonded to the first surface 210 of the piezoelectric element 200 via a first adhesive layer 310. Furthermore, the metal housing 400 and the second surface 220 of the piezoelectric element 200 are bonded together via a second adhesive layer 410. In this way, the unit formed by the positive electrode 500 and the terminal block 300, the piezoelectric element 200, and the metal housing 400 can be completed in the same process, simplifying the manufacturing process and reducing manufacturing costs.
[0047] Based on the above embodiments, the first adhesive layer 310 can be a conductive adhesive layer with conductive particle filler, and / or, the second adhesive layer 410 can also be a conductive adhesive layer with conductive particle filler. In one possible implementation, the thickness of the adhesive layer can be controlled by controlling the diameter of the conductive particle filler. For example, if 20 μm conductive particle filler is added, the thickness of the first adhesive layer 310 can be less than or equal to 20 μm. And / or, the thickness of the second adhesive layer 410 can also be less than or equal to 20 μm, thereby ensuring production consistency.
[0048] Alternatively, in another possible implementation, the first adhesive layer 310 may also be an adhesive without conductive particle fillers, and / or the second adhesive layer 410 may also be an adhesive without conductive particle fillers. In this way, the thickness of the first adhesive layer 310 and / or the second adhesive layer 410 can be controlled to be sufficiently thin by pressure. For example, the thickness of the first adhesive layer 310 and / or the second adhesive layer 410 may be less than or equal to 10 μm, and the adhesive layer can still achieve the requirement of conductivity; this embodiment of the application is not limited thereto.
[0049] Continue to refer to Figure 4 Based on the above embodiments, in one possible implementation, at least a portion of the terminal block 300 can be a flat plate structure, which can be connected to the first surface 210 of the piezoelectric element 200 via a first adhesive layer 310. In this way, the terminal block 300 can have a sufficiently large area to bond with the piezoelectric element 200.
[0050] Continue to refer to Figure 2 Based on the above embodiments, in one possible implementation, such as Figure 3 As shown, the positive wire 500 and the terminal 300 can be connected by soldering. In this way, the end of the positive wire 500 near the terminal 300 can be soldered to the terminal 300, while one side of the terminal 300 is soldered to the positive wire 500, and the other side of the terminal 300 is bonded to the first surface 210 of the piezoelectric body 200.
[0051] Continue to refer to Figure 2 Based on the above embodiments, in another possible implementation, such as Figure 4 As shown, the positive wire 500 and the terminal 300 can be connected by crimping. In this way, the end of the positive wire 500 near the terminal 300 can be crimped to the terminal 300, while one side of the terminal 300 is crimped to the positive wire 500, and the other side of the terminal 300 is bonded to the first surface 210 of the piezoelectric body 200.
[0052] Based on the above embodiments, considering the connection strength between the terminal block 300 and the piezoelectric element 200, and to facilitate bonding between the terminal block 300 and the piezoelectric element 200, the area of the flat plate structure can be greater than or equal to 8 mm². 2 The embodiments described in this application are not intended to be limiting.
[0053] It is understood that, based on the above embodiments, the terminal block 300 can be made of a metal material with good electrical conductivity. For example, the terminal block 300 can be made of metals such as gold, silver, copper, aluminum, or stainless steel; this application does not impose any limitations on this.
[0054] Continue to refer to Figure 2 Based on the above embodiments, the ultrasonic transducer structure 100 may further include a matching layer 600. The matching layer 600 may be located on the side of the metal housing 400 facing away from the piezoelectric element 200, and the matching layer 600 and the metal housing 400 may be bonded together via a third adhesive layer 610. It is understood that the selection of the third adhesive layer 610 may be the same as that of the first adhesive layer 310 and / or the second adhesive layer 410 described above; this embodiment will not be described in detail here.
[0055] It is understood that, based on the above embodiments, in one possible implementation, the wavelength of the matching layer 600 can be λ. In the embodiments of this application, the thickness of the matching layer 600 can be approximately equal to 1 / 4λ. Exemplarily, the thickness of the matching layer 600 can be 1 / 4λ. Thus, setting the thickness of the matching layer 600 to 1 / 4λ can improve the transmission efficiency of the ultrasonic transducer structure 100.
[0056] Continue to refer to Figure 1 Based on the above embodiments, the ultrasonic transducer structure 100 may further include a negative electrode line 700. The negative electrode line 700 may be disposed on one side of the metal housing 400, and may be fixedly connected to the metal housing 400. In one possible implementation, the negative electrode line 700 may be connected to the metal housing 400 by welding. The welding method may be soldering or resistance welding, and this application embodiment does not impose any limitations.
[0057] In this embodiment, when an alternating current of a certain frequency is applied between the positive wire 500 and the negative wire 700, the first adhesive layer 310 and / or the second adhesive layer 410 are conductive adhesive layers with conductive particle fillers, thereby making the connection between the terminal 300, the piezoelectric element 200, and the metal housing 400 conductive. The piezoelectric element 200 vibrates due to the inverse piezoelectric effect, and transmits the sound waves through the matching layer 600, thereby mounting one or more pairs of transducers on the flow channel and measuring the flow rate by measuring the time difference.
[0058] refer to Figure 5 Based on the above embodiments, the ultrasonic transducer structure 100 may further include a backing portion 800. In one possible implementation, the metal housing 400 may have an open receiving cavity 420. The receiving cavity 420 is for placing the piezoelectric element 200, and the opening of the receiving cavity 420 faces the piezoelectric element 200. In this embodiment, the backing portion 800 may be located within the receiving cavity 420, and the backing portion 800 may be located on one side of the piezoelectric element 200 in the second direction. It is understood that there is a gap between the piezoelectric element 200 and the receiving cavity 420 of the metal housing 400, and the backing portion 800 may be injection molded into a portion of the gap, thereby enabling the backing portion 800 to cover at least a portion of the piezoelectric element 200.
[0059] It is understood that, based on the above embodiments, in one possible implementation, the backing portion 800 may be made of polyester elastomer. In this way, by injection molding a layer of polyester elastomer onto one side of the piezoelectric body 200 in the second direction, noise from the piezoelectric body 200 in both the first and second directions can be suppressed.
[0060] It should be noted that, for ease of description, in the embodiments of this application, the first direction can be the thickness direction of the piezoelectric body 200, i.e. Figure 5 The x-direction. The second direction can be the width direction of the piezoelectric element 200, i.e. Figure 5 The y-direction in the equation. The first direction is perpendicular to the second direction.
[0061] In this embodiment, the manufacturing process of the ultrasonic transducer structure 100 provided is as follows: First, the positive electrode 500 and the terminal block 300 are fixedly connected by welding or crimping, forming a whole. Then, under certain temperature and pressure, the terminal block 300 and the first surface 210 of the piezoelectric element 200 are bonded together by a first adhesive layer 310, and the metal housing 400 and the second surface 220 of the piezoelectric element 200 are bonded together by a second adhesive layer 410, so that the whole formed by the positive electrode 500 and the terminal block 300, the piezoelectric element 200, and the metal housing 400 are completed in the same process. Next, the negative electrode 700 is fixedly connected to the metal housing 400 by soldering or resistance welding. Finally, a backing layer is injection molded into the receiving cavity 420 of the metal housing 400, covering at least a portion of the piezoelectric element 200. Finally, the metal housing 400 and the matching layer 600 are bonded together by the third adhesive layer 610, completing the manufacturing of the ultrasonic transducer structure 100.
[0062] In this embodiment, the connection method between the piezoelectric element 200 and the positive electrode line 500 is improved by bonding with an adhesive layer. This solves the problem in the related technology where the high temperature generated during the welding process of the positive electrode line 500 and the piezoelectric element 200 weakens the piezoelectric characteristics of the piezoelectric element 200, avoids the influence of welding heat load, reduces the attenuation of the piezoelectric performance of the piezoelectric element 200, and thus improves the accuracy and stability of ultrasonic measurement.
[0063] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.
[0064] It should be noted that phrases such as "in specific implementations," "in some embodiments," "in this embodiment," and "exemplarily" in the specification indicate that the described embodiments may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.
[0065] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.
[0066] It should be readily understood that “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest manner, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on something” but also “on something” without an intermediate feature or layer therebetween (i.e., directly on something).
[0067] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.
[0068] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.
Claims
1. An ultrasonic transducer structure, characterized in that, include: A piezoelectric material having opposing first and second surfaces in a first direction; A terminal block is located on one side of the first surface of the piezoelectric body, and the terminal block and the first surface of the piezoelectric body are connected by a first adhesive layer; A metal housing, at least a portion of which is located on one side of the second surface of the piezoelectric element, and the metal housing and the second surface of the piezoelectric element are connected by a second adhesive layer; The positive wire is fixedly connected to the terminal block.
2. The ultrasonic transducer structure according to claim 1, characterized in that, The first adhesive layer and / or the second adhesive layer are conductive adhesive layers with conductive particles.
3. The ultrasonic transducer structure according to claim 1, characterized in that, At least a portion of the terminals are flat plate structures, and the flat plate structure and the first surface of the piezoelectric element are connected by the first adhesive layer.
4. The ultrasonic transducer structure according to claim 3, characterized in that, The positive wire and the terminal are welded or crimped together.
5. The ultrasonic transducer structure according to claim 3, characterized in that, The area of the flat plate structure is greater than or equal to 8mm. 2 .
6. The ultrasonic transducer structure according to claim 1, characterized in that, The first adhesive layer and / or the second adhesive layer are non-conductive adhesive layers, and the thickness of the first adhesive layer and / or the second adhesive layer is less than or equal to 10 μm.
7. The ultrasonic transducer structure according to any one of claims 1-6, characterized in that, The ultrasonic transducer structure further includes: a matching layer; The matching layer is located on the side of the metal housing facing away from the piezoelectric element, and the matching layer and the metal housing are connected by a third adhesive layer.
8. The ultrasonic transducer structure according to claim 7, characterized in that, The wavelength of the matching layer is λ, and the thickness of the matching layer is equal to 1 / 4λ.
9. The ultrasonic transducer structure according to any one of claims 1-6, characterized in that, The ultrasonic transducer structure also includes: a negative electrode wire; The negative electrode line is disposed on one side of the metal housing, and the negative electrode line is fixedly connected to the metal housing.
10. The ultrasonic transducer structure according to any one of claims 1-6, characterized in that, The ultrasonic transducer structure also includes: a backing portion; The metal housing has a receiving cavity for placing the piezoelectric element, the backing portion is located within the receiving cavity, and the backing portion is located on one side of the piezoelectric element in a second direction.