Probe and manufacturing method of ultrasonic transduction unit

Abstract

The invention provides a probe. The probe comprises a shell, an ultrasonic transduction unit and at least one circuit board, the ultrasonic transduction unit is arranged in the shell and comprises a substrate, a vibrating film and an anti-resonance structure. The vibratable film is disposed on the substrate and forms a cavity with the substrate. The anti-resonance structure is arranged on one side, opposite to the vibratable film, of the substrate and comprises a hard layer and an adhesive layer which are connected with each other. And the density of the adhesive layer is different from that of the hard layer. The at least one circuit board is electrically coupled to the ultrasonic transduction unit. The invention also provides a manufacturing method of the ultrasonic transduction unit.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic detection, and in particular to a method for manufacturing a probe and an ultrasonic transducer unit. Background Art

[0002] Ultrasonic transducers are transducers that can realize the mutual conversion between sound energy and electrical energy within the ultrasonic frequency range. Ultrasonic transducers can be mainly divided into three categories: 1. Transmitter; 2. Receiver; and 3. Transceiver. The transducer used to transmit ultrasonic waves is called a transmitter. When the transducer is in the transmitting state, it converts electrical energy into mechanical energy and then into sound energy. The transducer used to receive sound waves is called a receiver. When the transducer is in the receiving state, it converts sound energy into mechanical energy and then into electrical energy. In some cases, the transducer can be used as both a transmitter and a receiver, which is called a transceiver. Transceiver is the core content and one of the key technologies of ultrasonic technology. It is widely used in non-destructive testing, medical imaging, ultrasonic microscopy, fingerprint recognition and the Internet of Things.

[0003] In order to obtain clearer ultrasonic images, the signal-to-noise ratio of the ultrasonic transducer must reach a certain level within the usable spectrum. However, in current ultrasonic transducers, the substrate is prone to resonate at a specific film vibration frequency, resulting in a decrease in the signal-to-noise ratio of some frequencies in the film vibration spectrum, making it impossible to produce clear ultrasonic images. Summary of the invention

[0004] The invention provides a probe and a method for manufacturing an ultrasonic transducer unit thereof, which have better resolution of ultrasonic imaging and better process flexibility.

[0005] Based on the above-mentioned purpose, the present invention proposes a probe, which includes: a shell; an ultrasonic transducer unit, which is arranged in the shell, and the ultrasonic transducer unit includes: a substrate; a vibrating film, which is arranged on the substrate and forms a cavity with the substrate; and an anti-resonance structure, which is arranged on the side of the substrate facing away from the vibrating film, and the anti-resonance structure includes: a hard layer; and an adhesive layer, which is connected to the hard layer, and the density of the adhesive layer is different from the density of the hard layer; and at least one circuit board, which is electrically coupled to the ultrasonic transducer unit.

[0006] In a preferred embodiment, the hard layer is a glass plate, the adhesive layer is an epoxy resin layer, and the epoxy resin layer connects the substrate and the glass plate.

[0007] In a preferred embodiment, the hard layer includes a plurality of surface microstructures, and the plurality of surface microstructures are arranged on the side of the hard layer facing away from the substrate; the adhesive layer is arranged on the side of the plurality of surface microstructures facing away from the substrate and fills the plurality of surface microstructures.

[0008] In a preferred embodiment, the plurality of surface microstructures are arranged at equal intervals along at least one direction.

[0009] In a preferred embodiment, the multiple surface microstructures are multiple microgrooves, which are recessed from a surface of the hard layer facing away from the substrate and each has a groove bottom surface. There is a first distance between the surface of the hard layer and the groove bottom surface, and there is a second distance between the surface of the hard layer and a surface of the substrate facing the vibrating film. The percentage value of the first distance to the second distance is between 5% and 95%.

[0010] In a preferred embodiment, the hard layer further includes a central portion, and the plurality of surface microstructures are Fresnel acoustic lens layers disposed around the central portion.

[0011] In a preferred embodiment, the central portion has a plane facing away from the substrate, and the multiple surface microstructures are further wedge-shaped structures, each of the multiple wedge-shaped structures has an inclined surface facing away from the central portion, and the angle between the inclined surface of each wedge-shaped structure and the plane decreases as it moves away from the central portion.

[0012] In a preferred embodiment, the hard layer has a surface facing away from the substrate, the adhesive layer is connected to the surface of the hard layer, and the material of the adhesive layer includes a silver adhesive layer, or a mixture of epoxy resin and metal powder, glass powder, ceramic powder or silicon powder.

[0013] In a preferred embodiment, the hard layer has a surface facing away from the substrate and a recess recessed from the surface, and the orthographic projection of the cavity on the substrate is located within the orthographic projection of the recess on the substrate.

[0014] In a preferred embodiment, the hard layer also has a recess bottom surface defining the recess, a first distance between the recess bottom surface and the surface, a second distance between the surface of the hard layer and a surface of the substrate facing the vibrating film, and a percentage value of the first distance to the second distance is in the range of 5% to 95%.

[0015] In a preferred embodiment, the hard layer and the substrate are integrated.

[0016] Based on the above purpose, the present invention also proposes a method for manufacturing an ultrasonic transducer unit, which includes: forming a vibrating film on one side of a substrate; forming a cavity between the substrate and the vibrating film; forming an anti-resonance structure on the other side of the substrate facing away from the vibrating film, wherein the step of forming the anti-resonance structure includes forming a hard layer and a glue layer that are connected and have different densities.

[0017] Based on the above, in the probe of the embodiment of the present invention, the ultrasonic transducer unit is provided with an anti-resonance structure on the side of the substrate facing away from the vibrating film. The density of the hard layer of the anti-resonance structure is different from the density of the adhesive layer, which can effectively suppress the resonance phenomenon of the substrate, thereby improving the integrity of the vibration spectrum of the vibrating film. In other words, the ultrasonic transducer unit of this embodiment has a better signal-to-noise ratio within the vibration frequency range, which helps to improve the resolution of the ultrasonic image generated by the probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic side view of a probe according to a first embodiment of the present invention.

[0019] Figure 2 yes Figure 1 A schematic cross-sectional view of an ultrasonic transducer unit.

[0020] FIG. 3A to FIG. 3C yes Figure 2 A cross-sectional schematic diagram of the manufacturing process of an ultrasonic transducer unit.

[0021] Figure 4 is a schematic cross-sectional view of an ultrasonic transducer unit according to a second embodiment of the present invention.

[0022] Figure 5 yes Figure 4 Schematic diagram of the rear view of the ultrasonic transducer unit.

[0023] FIG. 6A to FIG. 6C yes Figure 4 A cross-sectional schematic diagram of the manufacturing process of an ultrasonic transducer unit.

[0024] Figure 7 is a schematic cross-sectional view of an ultrasonic transducer unit according to a third embodiment of the present invention.

[0025] Figure 8 is a schematic cross-sectional view of an ultrasonic transducer unit according to a fourth embodiment of the present invention.

[0026] Fig. 9 is a schematic cross-sectional view of an ultrasonic transducer unit according to a fifth embodiment of the present invention.

[0027] Fig.10 is a schematic cross-sectional view of an ultrasonic transducer unit according to a sixth embodiment of the present invention.

[0028] Fig.11 FIG. 4 is a schematic diagram showing the distribution of the signal-to-noise ratio versus frequency of ultrasonic transducer units according to multiple embodiments of the present invention and a comparative example. DETAILED DESCRIPTION

[0029] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0030] As used herein, "about", "approximately", "essentially", or "substantially" include the stated value and the average value within an acceptable deviation range of the particular value determined by one of ordinary skill in the art, taking into account the measurement in question and the particular amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within, for example, ±30%, ±20%, ±15%, ±10%, ±5%. Furthermore, as used herein, "about", "approximately", "essentially", or "substantially" can select a more acceptable deviation range or standard deviation depending on the measured property, cutting property or other property, and can apply to all properties without one standard deviation.

[0031] In the accompanying drawings, the thickness of layers, films, panels, regions, etc., is exaggerated for clarity. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it may be directly on or connected to another element, or an intermediate element may also exist. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there is no intermediate element. As used herein, "connection" may refer to physical and / or electrical connection. Furthermore, "electrical connection" may be the presence of other elements between two elements.

[0032] In addition, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element, as shown in the figures. It should be understood that relative terms are intended to include different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one figure is turned over, the elements described as being on the "lower" side of the other elements will be oriented on the "upper" side of the other elements. Therefore, the exemplary term "lower" can include both "lower" and "upper" orientations, depending on the particular orientation of the figure. Similarly, if the device in one figure is turned over, the elements described as being "below" or "below" other elements will be oriented as being "above" the other elements. Therefore, the exemplary terms "above" or "below" can include both above and below orientations.

[0033] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and description to refer to the same or like parts.

[0034] Figure 1 is a schematic side view of a probe according to a first embodiment of the present invention. Figure 2 yes Figure 1 A schematic cross-sectional view of an ultrasonic transducer unit. FIG. 3A to FIG. 3C yes Figure 2 A cross-sectional schematic diagram of the manufacturing process of an ultrasonic transducer unit. Figure 2 Omitted Figure 1 An illustration of the acoustic lens 270.

[0035] Please refer to Figure 1 The probe 10 includes a housing 100, an ultrasonic transducer unit 200 and a circuit board CB. The ultrasonic transducer unit 200 is disposed in the housing 100 and electrically coupled to the circuit board CB. In the present embodiment, the circuit board CB is, for example, a printed circuit board assembly (PCBA) or a flexible printed circuit (FPC), and the number thereof is, for example, two. The two circuit boards CB may be located at opposite sides of the ultrasonic transducer unit 200, and each is electrically coupled to the ultrasonic transducer unit 200 via the flexible printed circuit FPC.

[0036] However, the present invention is not limited thereto. In another embodiment, the number of the circuit board CB and the flexible circuit board FPC can be one, and they are electrically coupled to one side of the ultrasonic transducer unit 200. In another embodiment, the number of the circuit board CB can be two, and the number of the flexible circuit board FPC can be one, and the two circuit boards CB can be electrically coupled to the ultrasonic transducer unit 200 via the same flexible circuit board FPC. In another embodiment, the circuit board CB and the flexible circuit board FPC can also be replaced by an integrated flexible circuit board.

[0037] It should be noted that although Figure 1 The probe 10 only shows one ultrasonic transducer unit 200, but the present invention is not limited thereto. In practical applications, such as an ultrasonic imaging device, the probe may be provided with a plurality of ultrasonic transducer units 200 arranged in an array, and these ultrasonic transducer units 200 may correspond to one pixel in the ultrasonic image, respectively, but the present invention is not limited thereto.

[0038] The ultrasonic transducer unit 200 includes a substrate 210 and a vibrating film 230 disposed on the substrate 210. The vibrating film 230 and the substrate 210 may form a cavity CAV. For example, in the present embodiment, the ultrasonic transducer unit 200 further includes a first electrode E1 and a second electrode E2 disposed on opposite sides of the cavity CAV. The first electrode E1 is disposed on the substrate 210 at a position overlapping the cavity CAV and is covered by an insulating layer 221. Two opposite surfaces of the second electrode E2 are covered with insulating layers 222 and 223.

[0039] It is particularly noted that the second electrode E2, the insulating layer 222, and the portion of the insulating layer 223 above the cavity CAV constitute a vibrating film 230 of the ultrasonic transducer unit 200. More specifically, in the present embodiment, the ultrasonic transducer unit 200 is, for example, a capacitive micromachined ultrasonic transducer (CMUT). However, the present invention is not limited thereto. In another embodiment, the ultrasonic transducer unit may also be a piezoelectric micromachined ultrasonic transducer (PMUT). In the piezoelectric micromachined ultrasonic transducer, the aforementioned first electrode E1 and the second electrode E2 are both located above the cavity CAV and form a portion of the vibrating film.

[0040] For example, the first electrode E1 can be electrically coupled to a reference power source (e.g., ground). The second electrode E2 on the vibrating film 230 can be electrically coupled to a DC power source, and use the output voltage of the DC power source as a reference bias. In addition, the second electrode E2 is also electrically coupled to an AC power source. After receiving the DC bias voltage from the DC power source and the AC voltage from the AC power source, the second electrode E2 drives the vibrating film 230 to vibrate to generate an ultrasonic signal.

[0041] In order to suppress the resonance phenomenon of the substrate 210, such as the ringing effect generated by the substrate 210, the ultrasonic transducer unit 200 further includes an anti-resonance structure 250 disposed on the side of the substrate 210 facing away from the vibrating film 230. The anti-resonance structure 250 includes a hard layer 251 and a glue layer 252 having different densities. In the present embodiment, the glue layer 252 is connected between the substrate 210 and the hard layer 251. More specifically, the hard layer 251 is attached to the surface of the side of the substrate 210 facing away from the vibrating film 230 via the glue layer 252. In the present embodiment, the hard layer 251 is, for example, a glass plate, and the glue layer 252 is, for example, an epoxy layer, but is not limited thereto.

[0042] Fig.11 Curve A in FIG. 1 shows the distribution of the signal-to-noise ratio (SNR) of the ultrasonic transducer unit of the comparative example versus the frequency. Fig.11 The curve C2 in FIG. 1 shows the distribution of the signal-to-noise ratio of the ultrasonic transducer unit 200 of the present embodiment to the frequency. Fig.11 It can be seen that since the ultrasonic transducer unit of the comparative example is not provided with the anti-resonance structure 250 of the present embodiment, its signal-to-noise ratio near the frequency of 6 MHz and its multiples will be significantly reduced due to the vibration of the substrate, resulting in a decrease in imaging resolution.

[0043] That is to say, the anti-resonance structure 250 can ensure the integrity of the signal-to-noise ratio of the ultrasonic transducer unit 200 in the vibration spectrum of this embodiment. Therefore, compared with the ultrasonic transducer unit of the comparative example, the resolution of the ultrasonic image of the probe 10 can be significantly improved. In other words, the resolution of the ultrasonic image generated by the probe 10 can be significantly improved.

[0044] Furthermore, in this embodiment, the ultrasonic transducer unit 200 may also selectively include an acoustic lens 270. The acoustic lens 270 is disposed on the ultrasonic wave emitting side of the vibrating film 230 facing away from the substrate 210 (i.e. Figure 2 The acoustic lens 270 is adapted to focus the ultrasonic waves generated by the vibrating film 230 in space and transmit them to the target object, or transmit the ultrasonic waves reflected by the target object to the vibrating film 230, thereby enhancing the signal of the ultrasonic image.

[0045] The following is an exemplary description of the manufacturing process of the ultrasonic transducer unit 200. Figure 3A First, a vibrating film 230 is formed on one side of a substrate 210. The substrate 210 is, for example, a glass substrate or a wafer substrate, but is not limited thereto.

[0046] For example, the step of forming the vibrating film 230 may include sequentially forming a sacrificial layer SCL, an insulating layer 222 , a second electrode E2 , and an insulating layer 223 on the insulating layer 221 , wherein the sacrificial layer SCL overlaps the first electrode E1 on the substrate 210 .

[0047] The insulating layer 221, the insulating layer 222 and the insulating layer 223 are, for example, passivation layers, and may be, but are not limited to, a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, an aluminum oxide layer or a dielectric layer formed of other suitable dielectric materials. The material of the sacrificial layer SCL includes, for example, aluminum, copper, silver, or silicon oxide. Next, an etching step of the sacrificial layer SCL is performed to form a cavity CAV between the vibrating film 230 and the insulating layer 221 (or the substrate 210). Figure 3B shown.

[0048] Please refer to Figure 3C The manufacturing method of the ultrasonic transducer unit 200 further includes: forming an anti-resonance structure 250 on the other side of the substrate 210 facing away from the vibrating film 230. The step of forming the anti-resonance structure 250 includes forming a hard layer 251 and a glue layer 252 connected to each other and having different densities. For example, in this embodiment, the glue layer 252 is formed before the hard layer 251 is formed, but the present invention is not limited thereto.

[0049] In this embodiment, the method for manufacturing the ultrasonic transducer unit 200 may further selectively include: forming an acoustic lens 270 on a side of the vibrating film 230 that faces away from the substrate 210. The material of the acoustic lens 270 includes, for example, silicone, rubber or polybutadiene rubber.

[0050] At this point, the ultrasonic transducer unit 200 of this embodiment is manufactured. Figure 2 As shown, the ultrasonic transducer unit 200 includes a substrate 210, a vibrating film 230 and an anti-resonance structure 250. The vibrating film 230 is disposed on the substrate 210 and forms a cavity CAV with the substrate 210. The anti-resonance structure 250 is disposed on the side of the substrate 210 facing away from the vibrating film 230, and includes a hard layer 251 and a glue layer 252 connected to each other. Since the density of the hard layer 251 of the anti-resonance structure 250 is different from the density of the glue layer 252, the resonance phenomenon of the substrate 210 can be effectively suppressed, thereby improving the integrity of the vibration spectrum of the vibrating film 230.

[0051] Some other embodiments will be listed below to explain the present invention in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted. For the omitted parts, please refer to the aforementioned embodiments and will not be repeated below.

[0052] Figure 4 is a schematic cross-sectional view of an ultrasonic transducer unit according to a second embodiment of the present invention. Figure 5 yes Figure 4 Schematic diagram of the rear view of the ultrasonic transducer unit. FIG. 6A to FIG. 6C yes Figure 4 A cross-sectional schematic diagram of the manufacturing process of an ultrasonic transducer unit.

[0053] Please refer to Figure 4 and Figure 5 The ultrasonic transducer unit 200A of this embodiment is Figure 2 The difference between the ultrasonic transducer unit 200 and the ultrasonic transducer unit 200 is that the structure and composition of the anti-resonance structure are different. For example, in this embodiment, the hard layer 251A of the anti-resonance structure 250A may include a plurality of surface microstructures SMS disposed on the side of the hard layer 251A facing away from the substrate 210. It is particularly noted that, unlike Figure 2 The adhesive layer 252 is disposed between the hard layer 251 and the substrate 210. The adhesive layer 252A of this embodiment is disposed on the side of the surface microstructures SMS facing away from the substrate 210 and fills the surface microstructures SMS on the hard layer 251A.

[0054] In the present embodiment, the plurality of surface microstructures SMS are, for example, a plurality of microgrooves, and are arranged at equal intervals along at least one direction. For example, in the present embodiment, the surface microstructures SMS may be arranged at intervals along the first direction DR1 at a first pitch P1, and may be arranged at intervals along the first direction DR1 at a second pitch P2 (e.g., Figure 5 The first direction DR1 may be selectively perpendicular to the first direction DR2, but is not limited thereto.

[0055] The hard layer 251A further includes a plurality of protrusion structures defining a plurality of micro grooves. Each protrusion structure has a first width W1 and a second width W2 along the first direction DR1 and the second direction DR2, respectively. Preferably, the percentage value of the first width W1 to the first pitch P1 is in the range of 30% to 70%, and the percentage value of the second width W2 to the second pitch P2 is in the range of 30% to 70%.

[0056] From another point of view, the portion of the plurality of micro grooves (i.e., surface micro structures SMS) arranged along the first direction DR1 and between two adjacent convex structures has a first spacing S1 along the first direction DR1, and the other portion of the plurality of micro grooves arranged along the second direction DR2 and between two adjacent convex structures has a second spacing S2 along the second direction DR2. The percentage value of the first spacing S1 to the first pitch P1 is in the range of 30% to 70%, and the percentage value of the second spacing S2 to the second pitch P2 is in the range of 30% to 70%. For example, the micro grooves of the present embodiment can be formed by tool cutting, so the percentage value of the tool width to the cutting pitch is also in the range of 30% to 70%.

[0057] It is particularly noted that in this embodiment, the plurality of surface microstructures SMS may be interconnected. More specifically, the orthographic projection of the areas occupied by the surface microstructures SMS on the substrate 210 may be in a grid shape.

[0058] On the other hand, the surface microstructure SMS (i.e., micro groove) may be recessed from the surface 251s of the hard layer 251A facing away from the substrate 210, and may have a groove bottom surface BS. A first distance d1 is provided between the groove bottom surface BS and the back surface 251bs of the hard layer 251A facing away from the surface 251s. A second distance d2 is provided between the surface 251s and the back surface 251bs of the hard layer 251A. Preferably, the percentage value of the first distance d1 to the second distance d2 may be within a range of 5% to 95%.

[0059] The following is an exemplary description of the manufacturing process of the ultrasonic transducer unit 200A. Fig. 6A First, a vibrating film 230 is formed on one side of a substrate 210. The substrate 210 is, for example, a glass substrate or a wafer substrate, but is not limited thereto.

[0060] For example, the step of forming the vibrating film 230 may include sequentially forming a sacrificial layer SCL, an insulating layer 222 , a second electrode E2 , and an insulating layer 223 on the insulating layer 221 , wherein the sacrificial layer SCL overlaps the first electrode E1 on the substrate 210 .

[0061] The insulating layer 221, the insulating layer 222 and the insulating layer 223 are, for example, passivation layers, and may be, but are not limited to, a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer or a dielectric layer formed of other suitable dielectric materials. The material of the sacrificial layer SCL includes, for example, aluminum, copper, silver or silicon oxide. Next, an etching step of the sacrificial layer SCL is performed to form a cavity CAV between the vibrating film 230 and the insulating layer 221 (or the substrate 210). Figure 6B shown.

[0062] The manufacturing method of the ultrasonic transducer unit 200A further includes: forming an anti-resonance structure 250A on the other side of the substrate 210 facing away from the vibrating film 230. The step of forming the anti-resonance structure 250A includes forming a hard layer 251A and a glue layer 252A connected to each other and having different densities. For example, in this embodiment, the hard layer 251A is formed before the glue layer 252A is formed, but the present invention is not limited thereto.

[0063] It is particularly noted that, in this embodiment, the step of forming the hard layer 251A includes, for example, using a tool (not shown) to cut along the Figure 5 The surface 251s of the hard layer 251A facing away from the substrate 210 is cut in the first direction DR1 and the first direction DR2 to form a plurality of micro grooves (i.e., a plurality of surface micro structures SMS) recessed from the surface 251s. After the step of forming the plurality of surface micro structures SMS, a glue layer 252A is formed on one side of the surface 251s of the hard layer 251A, such as Figure 6C The adhesive layer 252A is, for example, a silver adhesive layer, or a mixture of epoxy resin and metal powder (such as tungsten or aluminum oxide), glass powder, ceramic powder, or silicon powder.

[0064] The manufacturing method of the ultrasonic transducer unit 200A may further selectively include: forming an acoustic lens 270 on a side of the vibrating film 230 that faces away from the substrate 210. The material of the acoustic lens 270 includes, for example, silicone, rubber, or polybutadiene rubber.

[0065] At this point, the ultrasonic transducer unit 200A of this embodiment is completed. Figure 4As shown, the ultrasonic transducer unit 200A includes a substrate 210, a vibrating film 230 and an anti-resonance structure 250A. The vibrating film 230 is disposed on the substrate 210 and forms a cavity CAV with the substrate 210. The anti-resonance structure 250A is disposed on the side of the substrate 210 that is opposite to the vibrating film 230, and includes a hard layer 251A and an adhesive layer 252A that are connected to each other. In addition to the density of the hard layer 251A of the anti-resonance structure 250A being different from the density of the adhesive layer 252A, the hard layer 251A is also provided with a plurality of surface microstructures SMS on a side surface 251s that is opposite to the substrate 210. Therefore, compared to Figure 2 The ultrasonic transducer unit 200A of the present embodiment can not only suppress the resonance phenomenon of the substrate 210, but also further improve the signal-to-noise ratio of the ultrasonic transducer unit 200A in the vibration spectrum (e.g. Fig.11 As shown in curve C2 and curve D, where curve D illustrates the distribution of the signal-to-noise ratio versus frequency of the ultrasonic transducer unit 200A of this embodiment).

[0066] Figure 7 FIG. 2 is a cross-sectional schematic diagram of an ultrasonic transducer unit according to a third embodiment of the present invention. Figure 7 The ultrasonic transducer unit 200B of this embodiment is Figure 4 The difference between the ultrasonic transducer unit 200A and the ultrasonic transducer unit 200A is that the configuration and arrangement of the surface microstructures are different. For example, in this embodiment, the hard layer 251B of the anti-resonance structure 250B has a central portion 251cp, and a plurality of surface microstructures SMS-B are arranged around the central portion 251cp.

[0067] It is particularly noted that these surface microstructures SMS-B can be a plurality of wedge-shaped structures, and each has an inclined surface IS facing away from the central portion 251cp. The angle θ between the inclined surface IS of each wedge-shaped structure and the plane FL of the central portion 251cp facing away from the substrate 210 decreases as it moves away from the central portion 251cp. More specifically, in this embodiment, these wedge-shaped structures can form a Fresnel acoustic lens with defocusing capability. In other words, these microstructures are a Fresnel acoustic lens layer, which has a plurality of Fresnel microstructures arranged concentrically relative to the central portion 251cp. In this embodiment, the glue layer 252B filling these wedge-shaped structures is, for example, a silver glue layer, or a mixture of epoxy resin and metal powder (such as tungsten or aluminum oxide), glass powder, ceramic powder, or silicon powder.

[0068] Fig.11 The curve E in FIG. 1 shows the distribution of the signal-to-noise ratio of the ultrasonic transducer unit 200B of this embodiment over the frequency. Fig.11 From the curve E and curve C2, we can see that compared with Figure 4Compared with the ultrasonic transducer unit 200A of the present embodiment, the signal-to-noise ratio of the ultrasonic transducer unit 200B in the vibration spectrum is further improved.

[0069] Figure 8 FIG. 4 is a cross-sectional view of an ultrasonic transducer unit according to a fourth embodiment of the present invention. Figure 8 The ultrasonic transducer unit 200C of this embodiment is Figure 2 The difference between the ultrasonic transducer unit 200 and the ultrasonic transducer unit 200 is that the composition and stacking method of the anti-resonance structure are different.

[0070] For example, in this embodiment, the hard layer 251C of the anti-resonance structure 250C has a plane FL facing away from the substrate 210, and the adhesive layer 252C is connected to the plane FL of the hard layer 251C. In this embodiment, the hard layer 251C is, for example, a glass layer. The material of the adhesive layer 252C includes, for example, a mixture of epoxy and tungsten.

[0071] Fig.11 The curve F in FIG. 1 shows the distribution of the signal-to-noise ratio of the ultrasonic transducer unit 200C of this embodiment over the frequency. Fig.11 From the curve F and curve C2, we can see that compared with Figure 2 The ultrasonic transducer unit 200 of this embodiment has a further improved signal-to-noise ratio in the vibration spectrum of the ultrasonic transducer unit 200C.

[0072] Fig. 9 FIG. 5 is a cross-sectional schematic diagram of an ultrasonic transducer unit according to a fifth embodiment of the present invention. Fig. 9 The ultrasonic transducer unit 200D of this embodiment is Figure 8 The difference between the ultrasonic transducer unit 200C and the anti-resonance structure 250D is that the configuration of the hard layer is different. For example, in this embodiment, the hard layer 251D of the anti-resonance structure 250D is further provided with a recess RS sunken from the surface 251s on the surface 251s facing away from the substrate 210, and the glue layer 252D covers the surface 251s of the hard layer 251D and fills the recess RS.

[0073] It is particularly noted that the orthographic projection of the cavity CAV on the substrate 210 is within the orthographic projection of the recess RS of the hard layer 251D on the substrate 210. That is, the cavity CAV is completely overlapped within the setting range of the recess RS. From another point of view, the setting of the recess RS allows the thickness of the portion of the hard layer 251D that overlaps the cavity CAV (or the vibrating film 230) to be significantly smaller than the other portion that does not overlap the cavity CAV. Since the hard layer 251D has a thicker thickness in the portion that does not overlap the cavity CAV, the handling requirements of the ultrasonic transducer unit 200D during the manufacturing process can be met.

[0074] For example, the hard layer 251D has a recess bottom surface BS" defining the recess RS, and a first distance d1" is provided between the recess bottom surface BS" and the back side 251bs of the hard layer 251D. A second distance d2" is provided between the surface 251s and the back side 251bs of the hard layer 251D. Preferably, the percentage value of the first distance d1" to the second distance d2" may be in the range of 5% to 95%.

[0075] Fig.11 The curve G in FIG. 1 shows the distribution of the signal-to-noise ratio of the ultrasonic transducer unit 200D of the present embodiment over the frequency. Fig.11 From the curve G and curve F, we can see that compared with Figure 8 The ultrasonic transducer unit 200C of this embodiment further improves the signal-to-noise ratio of the vibration spectrum of the ultrasonic transducer unit 200D of this embodiment.

[0076] Fig.10 FIG. 6 is a cross-sectional view of an ultrasonic transducer unit according to a sixth embodiment of the present invention. Fig.10 The ultrasonic transducer unit 200E of this embodiment is Fig. 9 The difference between the ultrasonic transducer unit 200D is that the material of the hard layer is different.

[0077] For example, in Fig. 9 In the ultrasonic transducer unit 200D of the embodiment, the substrate 210 is, for example, a wafer substrate, and the material of the hard layer 251D is, for example, glass. However, in the ultrasonic transducer unit 200E of the present embodiment, the substrate 210 and the hard layer 251E may be integrated, and may be, for example, formed of the same glass plate, wherein the notch RS is formed on the surface of the glass plate on the side facing away from the vibratable film 230.

[0078] Similarly, in Figure 4 , Figure 7 and Figure 8 In some other variant embodiments, Figure 4 Hard layer 251A, Figure 7 The hard layer 251B and Figure 8 The hard layers 251C and the substrate 210 may also be integrally formed, for example, by the same glass plate or wafer, but the present invention is not limited thereto.

[0079] It should be noted that Figure 4 Ultrasonic transducer unit 200A, Figure 7 The ultrasonic transducer unit 200B, Figure 8 Ultrasonic transducer unit 200C, Fig. 9 Ultrasonic transducer unit 200D and Fig.10 The ultrasonic transducer unit 200E can be used to replace Figure 1The ultrasonic transducer unit 200 in the probe 10 .

[0080] In summary, in the probe of the embodiment of the present invention, the ultrasonic transducer unit is provided with an anti-resonance structure on the side of the substrate facing away from the vibrating film. The density of the hard layer of the anti-resonance structure is different from the density of the adhesive layer, which can effectively suppress the resonance phenomenon of the substrate, thereby improving the integrity of the vibration spectrum of the vibrating film. In other words, the ultrasonic transducer unit of this embodiment has a better signal-to-noise ratio within the vibration frequency range, which helps to improve the resolution of the ultrasonic image generated by the probe.

[0081] The present invention has been described by the above-mentioned relevant embodiments, however, the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. A probe, characterized in that: include: shell; An ultrasonic transducer unit is disposed in the housing, and the ultrasonic transducer unit comprises: substrate; a vibratable film disposed on the substrate and forming a cavity with the substrate; and The anti-resonance structure is arranged on a side of the substrate facing away from the vibrating film, and the anti-resonance structure includes: a hard layer; and a glue layer connected to the hard layer, and the density of the glue layer is different from the density of the hard layer; and At least one circuit board is electrically coupled to the ultrasonic transducer unit.

2. The probe according to claim 1, characterized in that The hard layer is a glass plate, the adhesive layer is an epoxy resin layer, and the epoxy resin layer connects the substrate and the glass plate.

3. The probe according to claim 1, characterized in that The hard layer comprises a plurality of surface microstructures, and the plurality of surface microstructures are arranged on the side of the hard layer facing away from the substrate; the adhesive layer is arranged on the side of the plurality of surface microstructures facing away from the substrate and fills the plurality of surface microstructures.

4. The probe according to claim 3, characterized in that The plurality of surface microstructures are arranged at equal intervals along at least one direction.

5. The probe according to claim 4, characterized in that The multiple surface microstructures are multiple microgrooves, which are recessed from a surface of the hard layer facing away from the substrate and each has a groove bottom surface. There is a first distance between the surface of the hard layer and the groove bottom surface, and there is a second distance between the surface of the hard layer and a surface of the substrate facing the vibrating film. The percentage value of the first distance to the second distance is between 5% and 95%.

6. The probe according to claim 3, characterized in that The hard layer further comprises a central portion, and the plurality of surface microstructures are Fresnel acoustic lens layers arranged around the central portion.

7. The probe according to claim 6, characterized in that The central portion has a plane facing away from the substrate. The multiple surface microstructures are further wedge-shaped structures. Each of the multiple wedge-shaped structures has an inclined surface facing away from the central portion. The angle between the inclined surface of each wedge-shaped structure and the plane decreases as it moves away from the central portion.

8. The probe according to claim 1, characterized in that The hard layer has a surface facing away from the substrate. The adhesive layer is connected to the surface of the hard layer. The material of the adhesive layer includes a silver adhesive layer, or a mixture of epoxy resin and metal powder, glass powder, ceramic powder or silicon powder.

9. The probe according to claim 1, characterized in that: The hard layer has a surface facing away from the substrate and a recess recessed from the surface, and the orthographic projection of the cavity on the substrate is located within the orthographic projection of the recess on the substrate.

10. The probe according to claim 9, characterized in that The hard layer also has a recess bottom surface defining the recess, a first distance between the recess bottom surface and the surface, a second distance between the surface of the hard layer and a surface of the substrate facing the vibrating film, and a percentage value of the first distance to the second distance is in the range of 5% to 95%.

11. The probe according to claim 1, characterized in that The hard layer is integrated with the substrate.

12. A method for manufacturing an ultrasonic transducer unit, characterized in that: include: forming a vibrating thin film on one side of a substrate; forming a cavity between the substrate and the vibratable film; An anti-resonance structure is formed on the other side of the substrate facing away from the vibrating film, wherein the step of forming the anti-resonance structure includes forming a hard layer and a glue layer connected with each other and having different densities.

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