Heat conduction backing structure for ultrasonic transducer and ultrasonic transducer
By using a thermally conductive backing structure of an open-cell foam metal layer and a solid matrix in the ultrasonic transducer, the problem of insufficient thermal conductivity of the backing material is solved, achieving efficient heat dissipation and sound attenuation, and improving equipment performance and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2026-03-31
AI Technical Summary
The backing material of existing ultrasonic transducers has limited thermal conductivity, which leads to heat accumulation that affects performance and lifespan, and may also cause patient discomfort.
An open-cell foam metal layer is used as a thermally conductive backing structure. It has high porosity and is filled with a solid matrix. Combined with high acoustic impedance and low acoustic impedance particles, it enhances heat dissipation and sound attenuation performance and simplifies the production process.
It improves the heat dissipation efficiency of ultrasonic transducers, reduces the risk of heat accumulation, weakens ringing interference, and enhances the signal-to-noise ratio and image quality.
Smart Images
Figure CN224056003U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of ultrasonic detection technology, and in particular to a thermally conductive backing structure for an ultrasonic transducer and an ultrasonic transducer. Background Technology
[0002] Ultrasound has been widely used in medical imaging diagnosis due to its significant advantages, such as being radiation-free and providing real-time dynamic imaging. The upgrading of ultrasound transducers is a crucial part of the development of medical ultrasound diagnostic systems.
[0003] Piezoelectric ultrasonic probes are used in various fields such as medical diagnosis, treatment, and ultrasonic flaw detection. With the increasing demand for efficient and accurate diagnosis, higher and higher requirements are being placed on the performance of ultrasonic imaging equipment. Among the various performance aspects of piezoelectric ultrasonic probes, improving probe performance is one of the effective methods to improve the quality of detected images. However, with the development of software and electronic circuit technology, the performance of ultrasonic probes is increasingly becoming one of the bottlenecks in improving the image quality of ultrasonic imaging equipment.
[0004] Ultrasonic transducers utilize the piezoelectric effect of piezoelectric elements to convert the excitation electrical pulse signal of an ultrasonic system into an ultrasonic signal, which is then transmitted to the object being probed. The ultrasonic echo signal reflected from the object is then converted back into an electrical signal, thus enabling the detection of the object. During this conversion, some energy is inevitably converted into heat. As a result, heat accumulates continuously within the ultrasonic transducer during use, causing its internal temperature to rise. This heat accumulation not only affects the transducer's performance, leading to reduced image quality, but also severely shortens its lifespan and limits its application in heat-sensitive environments. Furthermore, the continuous heat buildup within the transducer can cause patient discomfort and even pose a safety hazard during use. Therefore, the transducer's heat dissipation capacity must be fully considered during the design phase.
[0005] The backing material is a crucial component of the ultrasonic transducer structure. Its main function is to absorb the acoustic energy radiated backward by the piezoelectric element, reducing the interference of acoustic wave reflection on the transducer's performance. Simultaneously, because it is tightly connected to the piezoelectric element from the back, it can transfer the heat generated by the piezoelectric element to the rear metal support for heat dissipation. However, currently, the thermal conductivity (heat dissipation) of the backing material is limited.
[0006] Generally, ultrasonic transducer backing materials are composite materials with specific acoustic impedance and high attenuation, formulated by blending epoxy resin, lightweight fillers (low acoustic impedance), and heavyweight fillers (high acoustic impedance) in a certain proportion. In addition, to enhance the thermal conductivity (heat dissipation) of the backing material, thermally conductive fillers are usually added, including metal powders such as silver and aluminum, or inorganic non-metallic powders such as aluminum nitride, boron nitride, and carbon materials. However, adding thermally conductive fillers creates microscopic thermal conduction pathways, and the proportion added is limited, so it cannot efficiently improve the thermal conductivity (heat dissipation) of the backing material. Utility Model Content
[0007] To address the aforementioned problems, this application provides a thermally conductive backing structure and an ultrasonic transducer. The design is ingenious and the structure is simple. The high thermal conductivity of the open-cell foam metal improves the thermal conductivity of the backing material, enabling it to quickly conduct heat away from the piezoelectric element and reducing the risk of heat accumulation within the ultrasonic transducer. The open-cell foam metal has a loose pore structure and high porosity, allowing reverse ultrasonic waves to be efficiently absorbed and attenuated after penetrating the open-cell foam metal layer, ensuring the high acoustic attenuation characteristics of the backing material and reducing ringing interference. By employing open-cell foam metal, this application achieves both good acoustic attenuation characteristics and good thermal conductivity (heat dissipation) performance of the backing material while meeting the thickness requirements of the backing structure. The technical solution adopted in this application is as follows:
[0008] A thermally conductive backing structure for an ultrasonic transducer includes: an open-cell foam metal layer, wherein the pores of the open-cell foam metal layer are filled with a solid matrix.
[0009] The high thermal conductivity of open-cell foam metal improves the thermal conductivity of the backing material, enabling it to quickly conduct heat away from the piezoelectric element and reducing the risk of heat accumulation within the ultrasonic transducer. The open-cell foam metal has a loose pore structure and high porosity, allowing reverse ultrasonic waves to be efficiently absorbed and attenuated after penetrating the open-cell foam metal layer, ensuring high acoustic attenuation characteristics and reducing ringing interference. This application, by using open-cell foam metal, achieves both good acoustic attenuation characteristics and good thermal conductivity (heat dissipation) performance in the backing material while meeting the thickness requirements of the backing structure. The thermally conductive backing structure provided by this application eliminates the need for heat sinks (aluminum sheets, graphite sheets, etc.) on both sides of the backing structure, simplifying the manufacturing process.
[0010] In some embodiments, the pore density of the open-cell foam metal layer is 5ppi-20ppi.
[0011] By selecting a pore density of 5ppi-20ppi for the open-cell foam metal layer, two advantages are achieved: firstly, excessively high pore density, while improving sound attenuation, increases the manufacturing difficulty of the open-cell foam metal; secondly, excessively low pore density, while reducing manufacturing difficulty, results in poor sound attenuation. Selecting a pore density between 5ppi and 20ppi achieves good sound attenuation without increasing the manufacturing difficulty and cost of the open-cell foam metal.
[0012] In some embodiments, the solid matrix contains a mixture of high acoustic impedance particles and low acoustic impedance particles to provide sound scattering.
[0013] By using a mixture of high acoustic impedance particles and low acoustic impedance particles, the scattering effect of the backing structure on reverse ultrasonic waves is improved, thereby enhancing the acoustic attenuation effect of the backing structure.
[0014] In some embodiments, the high acoustic impedance particles are one or a combination of tungsten and tungsten carbide.
[0015] In some embodiments, the low acoustic impedance particles are one or a combination of two of aluminum and aluminum alloys.
[0016] In some embodiments, the solid matrix contains thermally conductive particles. By incorporating these particles, the thermal conductivity (heat dissipation) of the backing structure is further enhanced.
[0017] In some embodiments, the open-cell foam metal layer is made of copper, nickel, or aluminum.
[0018] In some embodiments, the solid matrix is one of epoxy resin, polyurethane or silicone resin.
[0019] In some embodiments, the perforated foam metal layer is grounded. By grounding the perforated foam metal layer, it can produce a shielding effect, which helps to reduce the noise of the ultrasonic transducer, thereby improving the signal-to-noise ratio and enhancing the performance of the ultrasonic transducer.
[0020] On the other hand, this application provides an ultrasonic transducer, including a piezoelectric layer and the aforementioned thermally conductive backing structure, wherein the thermally conductive backing structure is disposed on the back side of the piezoelectric layer.
[0021] The thermally conductive backing structure for an ultrasonic transducer provided in this application has at least one of the following beneficial effects:
[0022] 1. This application provides a thermally conductive backing structure for an ultrasonic transducer. The high thermal conductivity of the open-cell foam metal improves the thermal conductivity of the backing material, enabling it to quickly conduct heat away from the piezoelectric element and reducing the risk of excessive heat accumulation within the ultrasonic transducer. The open-cell foam metal has a loose pore structure and high porosity, allowing reverse ultrasonic waves to be efficiently absorbed and attenuated after penetrating the open-cell foam metal layer, ensuring high acoustic attenuation characteristics and reducing ringing interference. By using open-cell foam metal, this application achieves both good acoustic attenuation characteristics and good thermal conductivity (heat dissipation) performance in the backing material while meeting the thickness requirements of the backing structure. The thermally conductive backing structure provided by this application eliminates the need for heat sinks (aluminum sheets, graphite sheets, etc.) on both sides of the backing structure, simplifying the manufacturing process.
[0023] 2. This application provides a thermally conductive backing structure for an ultrasonic transducer. By selecting the pore density of the open-cell foam metal layer between 5ppi and 20ppi, it avoids two problems: firstly, excessively high pore density, while improving the sound attenuation effect, increases the manufacturing difficulty of the open-cell foam metal; secondly, excessively low pore density, while reducing the manufacturing difficulty, results in poor sound attenuation. Selecting a pore density between 5ppi and 20ppi achieves good sound attenuation without increasing the manufacturing difficulty of the open-cell foam metal, thus reducing its acquisition cost.
[0024] 3. The thermally conductive backing structure for an ultrasonic transducer provided in this application improves the scattering effect of the backing structure on the reverse ultrasonic waves by setting a mixture of high acoustic impedance particles and low acoustic impedance particles, thereby improving the acoustic attenuation effect of the backing structure.
[0025] 4. The thermally conductive backing structure for an ultrasonic transducer provided in this application further enhances the thermal conductivity (heat dissipation) capability of the backing structure by setting thermally conductive particles.
[0026] 5. The thermally conductive backing structure for an ultrasonic transducer provided in this application can generate a shielding effect by grounding the perforated foam metal layer, which helps to reduce the noise of the ultrasonic transducer, thereby improving the signal-to-noise ratio and enhancing the performance of the ultrasonic transducer. Attached Figure Description
[0027] The preferred embodiments will now be described in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further explain the aforementioned characteristics, technical features, advantages, and implementation methods of a thermally conductive backing structure for an ultrasonic transducer and the ultrasonic transducer itself:
[0028] Figure 1 This is a schematic diagram of the fabrication of the backing structure in this application.
[0029] Explanation of icon numbers:
[0030] 1. Filler material, 2. Perforated foam metal, 3. Casting mold, 4. Support component. Detailed Implementation
[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.
[0032] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."
[0033] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.
[0034] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0035] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0036] This application provides a thermally conductive backing structure for an ultrasonic transducer, comprising: an open-cell foam metal layer, wherein the pores of the open-cell foam metal layer are filled with a solid matrix. It is understood that the high thermal conductivity of the open-cell foam metal improves the thermal conductivity of the backing material, enabling the backing material to quickly conduct heat away from the piezoelectric element, reducing the risk of excessive heat accumulation within the ultrasonic transducer. The open-cell foam metal has a loose pore structure and high porosity, allowing reverse ultrasonic waves to be efficiently absorbed and attenuated after penetrating the open-cell foam metal layer, ensuring the high acoustic attenuation characteristics of the backing material and reducing ringing interference. By using open-cell foam metal, this application achieves both good acoustic attenuation characteristics and good thermal conductivity (heat dissipation) performance of the backing material while meeting the thickness requirements of the backing structure. The thermally conductive backing structure provided by this application eliminates the need for heat sinks (aluminum sheets, graphite sheets, etc.) on both sides of the backing structure, simplifying the manufacturing process of the backing structure.
[0037] In this embodiment, the open-cell foam metal layer can be made of copper, nickel, or aluminum. The solid matrix can be epoxy resin, polyurethane, or silicone resin. This application preferably uses commonly used epoxy resin.
[0038] In one embodiment, the pore density of the open-cell foam metal layer is 5ppi-20ppi.
[0039] It is worth noting that by selecting a pore density of 5ppi-20ppi for the open-cell foam metal layer, two advantages are achieved: firstly, excessively high pore density, while improving sound attenuation, increases the manufacturing difficulty of the open-cell foam metal; secondly, excessively low pore density, while reducing manufacturing difficulty, results in poor sound attenuation. Selecting a pore density between 5ppi and 20ppi achieves good sound attenuation without increasing the manufacturing difficulty of the open-cell foam metal, thus reducing its acquisition cost.
[0040] In one embodiment, the solid matrix contains a mixture of high acoustic impedance particles and low acoustic impedance particles to provide sound scattering. It is worth noting that by incorporating a mixture of high and low acoustic impedance particles, the scattering effect of the backing structure on reverse ultrasonic waves is enhanced, thereby improving the sound attenuation effect of the backing structure.
[0041] Specifically, the high acoustic impedance particles can be one or more combinations of tungsten, tungsten carbide, or tungsten-based metal compounds. The low acoustic impedance particles can be one or more combinations of aluminum, aluminum alloys, or other lightweight metals. In other embodiments, the solid matrix contains medium acoustic impedance particles, such as copper or copper alloys.
[0042] In one embodiment, the solid matrix contains thermally conductive particles. These particles can be metallic powders such as silver or aluminum, or inorganic non-metallic powders such as aluminum nitride, boron nitride, or carbon materials. By incorporating these thermally conductive particles, the thermal conductivity (heat dissipation) of the backing structure is further enhanced.
[0043] In one embodiment, the perforated foam metal layer is grounded. It is worth noting that by grounding the perforated foam metal layer, it can generate a shielding effect, which helps reduce the noise of the ultrasonic transducer, thereby improving the signal-to-noise ratio and enhancing the performance of the ultrasonic transducer.
[0044] Implementation plan for thermally conductive backing structure: Reference Figure 1 First, the perforated foam metal 2 is machined to the designed dimensions. The perforated foam metal 2 is then assembled with the support component 4, and finally placed into the casting mold 3 to obtain the casting part. After fully preheating the casting part, the filler material 1 (which becomes a solid matrix after curing) is poured into the casting part, allowing the filler material 1 to flow naturally and fill the pores of the perforated foam metal 2. Alternatively, the mold containing the filler material 1 can be placed in an ultrasonic cleaning tank, and ultrasonic vibration can be activated to ensure the filler material 1 fully fills the pores. After the filler material 1 fills the pores of the perforated foam metal 2, it should be 1-2 mm higher than the perforated foam metal. Finally, after curing and demolding, the casting part is obtained. After surface processing of the casting part, the thermally conductive backing structure is obtained.
[0045] This application also provides an ultrasonic transducer, including a piezoelectric layer and the aforementioned thermally conductive backing structure, wherein the thermally conductive backing structure is disposed on the back side of the piezoelectric layer. The specific structure of the thermally conductive backing structure is as described in the foregoing embodiments. The material of the piezoelectric layer is typically piezoelectric ceramic; however, it is understood that the material of the piezoelectric layer can also be a piezoelectric crystal or a piezoelectric composite material. Since this ultrasonic transducer adopts the technical solutions of the foregoing embodiments, it at least possesses the beneficial effects brought about by the technical solutions of the foregoing embodiments, which will not be elaborated upon here.
[0046] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.
Claims
1. A thermally conductive backing structure for an ultrasonic transducer, characterized by, Comprising: an open cell metal foam layer having a solid matrix filling the pores of the open cell metal foam layer.
2. A thermally conductive backing structure for an ultrasonic transducer according to claim 1, wherein, The open cell metal foam layer has a pore density of 5 ppi to 20 ppi.
3. A thermally conductive backing structure for an ultrasonic transducer according to claim 1, wherein, The solid matrix contains a mixture of high acoustic impedance particles and low acoustic impedance particles to provide acoustic scattering.
4. A thermally conductive backing structure for an ultrasonic transducer according to claim 3, wherein, The high acoustic impedance particles are one or a combination of tungsten, tungsten carbide.
5. A thermally conductive backing structure for an ultrasonic transducer according to claim 3, wherein, The low acoustic impedance particles are one or a combination of aluminum, aluminum alloy.
6. A thermally conductive backing structure for an ultrasonic transducer according to claim 1, wherein, The solid matrix contains thermally conductive particles.
7. A thermally conductive backing structure for an ultrasonic transducer according to claim 1, wherein, The open cell metal foam layer is one of copper, nickel, or aluminum.
8. A thermally conductive backing structure for an ultrasonic transducer according to any one of claims 1-7, characterized in that, The solid matrix is one of epoxy, polyurethane, or silicone.
9. A thermally conductive backing structure for an ultrasonic transducer according to claim 8, wherein, The open cell metal foam layer is grounded.
10. An ultrasonic transducer, characterized by, A piezoelectric layer and a thermally conductive backing structure according to any one of claims 1-9 disposed on a back side of the piezoelectric layer.