Piezoelectric ultrasonic transducer and method of manufacturing the same

Abstract

The application discloses a piezoelectric ultrasonic transducer and a manufacturing method thereof, and relates to the technical field of piezoelectric ultrasonic transducers, which comprises a flexible electronic circuit structure, a piezoelectric structure and an outer electrode structure arranged in sequence from inside to outside, a channel for drugs or guide wires to pass through is formed on the inner side of the flexible electronic circuit structure, the piezoelectric structure comprises a piezoelectric base body and a plurality of piezoelectric columns, the plurality of piezoelectric columns are embedded on the piezoelectric base body, a plurality of electrode points are arranged on the flexible electronic circuit structure, the electrode points correspond to and contact the piezoelectric columns one by one, each electrode point is connected to a first electrode lead wire one by one, the outer electrode structure contacts each piezoelectric column, and the outer electrode structure is connected to a second electrode lead wire. The application can play a role of intravascular ultrasonic imaging in an interventional operation, can assist doctors in precise intervention in the operation process, and improves the success rate of the operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of piezoelectric ultrasonic transducer, in particular to a piezoelectric ultrasonic transducer and a manufacturing method thereof. BACKGROUND

[0002] Interventional therapy is a new type of high-tech minimally invasive treatment technology, which has the characteristics of small trauma, multiple indications, definite curative effect, rapid postoperative recovery and the like, and is an important development trend of future medicine. Among the interventional therapy technologies, vascular interventional therapy is the highest technical requirement and access barrier in the subdivided field. At present, the vascular intervention is mainly through the operation of the guide wire catheter into the blood vessel, and is assisted by the ultrasonic imaging technology. Since the operation of the guide wire for vascular intervention is a remote control technology, that is, the body of the guide wire is indirectly driven to operate the head of the guide wire, therefore, the success rate of the operation intervention requires the doctor to have very rich clinical experience, and when passing through some narrow structures, the difficulty will be greatly increased. These narrow structures of the blood vessels are various, and the microstructure may be very complex, central, eccentric, zigzag, septal and the like. Therefore, in such a case, it is very difficult to directly aim at the narrow structure of the blood vessel for the guide wire, and the narrow micro three-dimensional structure cannot be completely displayed in real time under the DSA (digital subtraction angiography) or ultrasonic imaging. SUMMARY

[0003] The purpose of the present application is to provide a piezoelectric ultrasonic transducer and a manufacturing method thereof, which can play a role of intravascular ultrasonic imaging in interventional surgery, and can assist the doctor in precise intervention during the operation process, thereby improving the success rate of the operation.

[0004] To achieve the above-mentioned purpose, the present application provides the following scheme:

[0005] The present application provides a piezoelectric ultrasonic transducer, which comprises a flexible electronic circuit structure, a piezoelectric structure and an outer electrode structure which are sequentially arranged from inside to outside, a channel for passing through a drug or a guide wire is formed on the inner side of the flexible electronic circuit structure, the piezoelectric structure comprises a piezoelectric base body and a plurality of piezoelectric columns, the plurality of piezoelectric columns are embedded on the piezoelectric base body, a plurality of electrode points are arranged on the flexible electronic circuit structure, the electrode points correspond to and contact the piezoelectric columns one by one, each electrode point is connected to a first electrode lead wire one by one, the outer electrode structure contacts each piezoelectric column, and the outer electrode structure is connected to a second electrode lead wire.

[0006] Preferably, a transparent matching structure is further included, the transparent matching structure is located on the outer side of the outer electrode structure, and the thickness of the transparent matching structure is set according to one quarter of the wavelength corresponding to the frequency set by the piezoelectric ultrasonic transducer.

[0007] Preferably, a backing structure is further included, which is located on the inner side of the flexible electronic circuit structure, and is made of polyurethane foam.

[0008] Preferably, the piezoelectric base is made of silicone rubber, and includes a first cylindrical portion and a first bottom portion, the first cylindrical portion is embedded with a plurality of piezoelectric columns, the first bottom portion is embedded with a plurality of piezoelectric columns, the first bottom portion is arranged at one end of the first cylindrical portion, the other end of the first cylindrical portion is open, and the first bottom portion is provided with a first through hole.

[0009] Preferably, the flexible electronic circuit structure includes a second cylindrical portion and a second bottom portion, the second bottom portion is arranged at one end of the second cylindrical portion, the second bottom portion corresponds to the first bottom portion, the other end of the second cylindrical portion is open, and the second bottom portion is provided with a second through hole.

[0010] Preferably, the outer electrode structure includes a third cylindrical portion and a third bottom portion, the third bottom portion is arranged at one end of the third cylindrical portion, the third bottom portion corresponds to the first bottom portion, the other end of the third cylindrical portion is open, and the third bottom portion is provided with a third through hole.

[0011] Preferably, the transparent matching structure includes a fourth cylindrical portion and a fourth bottom portion, the fourth bottom portion is arranged at one end of the fourth cylindrical portion, the fourth bottom portion corresponds to the first bottom portion, the other end of the fourth cylindrical portion is open, and the fourth bottom portion is provided with a fourth through hole.

[0012] Preferably, the backing structure is in a cylindrical shape, both ends of the backing structure are provided with openings, and an internal passage in the backing structure is used for passing drugs or guide wires.

[0013] Preferably, the piezoelectric column is made of piezoelectric ceramic or piezoelectric quartz crystal, the polarization direction of the piezoelectric column is the thickness direction, the polarization direction of the piezoelectric column is consistent with the direction of the electric field, and the thickness of the piezoelectric column corresponds to the wavelength set according to the thickness resonance frequency of 5-10 MHz set by the piezoelectric ultrasonic transducer.

[0014] The application further provides a manufacturing method of the piezoelectric ultrasonic transducer, including the following steps:

[0015] Step one, according to the thickness resonance frequency of the piezoelectric ultrasonic transducer, a piezoelectric sheet with a corresponding thickness is selected, and the piezoelectric sheet is cut along the X direction and the Y direction in a proportional manner, the cutting surface is a positive electrode surface, after cutting, silicone rubber is filled between the piezoelectric columns and the outside of the outermost piezoelectric column, to form a planar structure of the first cylindrical portion with piezoelectric columns and the first bottom portion with piezoelectric columns;

[0016] Step two, according to the arrangement position of the piezoelectric column, a planar structure of the second cylindrical part with adhesive capacity and a second bottom are printed by using a flexible electronic printing process:

[0017] Step three, the planar structure of the second cylindrical part is pasted with the planar structure of the first cylindrical part with piezoelectric columns, the second bottom is pasted with the first bottom with piezoelectric columns, and each electrode point in the flexible electronic circuit corresponds to each piezoelectric column position in the flexible piezoelectric composite structure and is electrically connected;

[0018] Step four, the planar structure of the first cylindrical part and the planar structure of the second cylindrical part after being adhered are rolled into a cylindrical shape, and the second bottom after being adhered is arranged at one end of the first cylindrical part with the first bottom with piezoelectric columns;

[0019] Step five, an outer electrode structure is covered on the outer side of the piezoelectric structure, and one end of the second lead wire is connected with the outer electrode structure;

[0020] Step six, a backing structure is arranged on the inner side of the flexible electronic circuit structure;

[0021] Step seven, a transparent matching structure is arranged on the outer side of the outer electrode structure.

[0022] The present application has the following technical effects compared with the prior art:

[0023] The piezoelectric ultrasonic transducer of the present application is installed at the front end of a guide wire catheter and is suitable for intravascular ultrasound imaging, integrates piezoelectric column array elements, and can perform omnidirectional ultrasound imaging on the blood vessel wall and the front end of the catheter. Compared with the conventional transducer, the present application combines the flexible electronic printing technology, greatly facilitates the lead-out of the electrode line of the piezoelectric column, and provides a brand-new idea for complex array type piezoelectric ultrasonic transducers. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0025] Figure 1 It is an exploded view of the piezoelectric ultrasonic transducer of the present application;

[0026] Figure 2 It is an external view of the piezoelectric ultrasonic transducer of the present application;

[0027] Figure 3 It is a schematic view of the piezoelectric sheet of the present application;

[0028] Figure 4A schematic diagram of a piezoelectric sheet after cutting according to the present application;

[0029] Figure 5 A schematic diagram of a piezoelectric column after cutting according to the present application;

[0030] Figure 6 A schematic diagram of a piezoelectric structure in a planar form after filling with silicone rubber for a piezoelectric column according to the present application;

[0031] Figure 7 A schematic diagram of a flexible electronic circuit structure in a planar form according to the present application;

[0032] Figure 8 A schematic diagram of a flexible electronic circuit structure in a planar form connected with a piezoelectric structure in a planar form according to the present application;

[0033] Figure 9 A schematic diagram of a flexible electronic circuit structure connected with a piezoelectric structure according to the present application;

[0034] Figure 10 A schematic diagram of a piezoelectric column of a piezoelectric structure corresponding to an electrode point of a flexible electronic circuit structure according to the present application;

[0035] Figure 11 A schematic diagram of an external electrode structure according to the present application;

[0036] Figure 12 A schematic diagram of a through-bonding matching structure according to the present application;

[0037] Figure 13 A schematic diagram of a backing structure according to the present application;

[0038] Wherein: 1-backing structure, 2-flexible electronic circuit structure, 3-piezoelectric structure, 4-external electrode structure, 5-through-bonding matching structure, 6-piezoelectric base, 7-piezoelectric column, 8-electrode point, 9-first electrode lead, 10-first cylindrical part, 11-first bottom part, 12-first through-hole, 13-third cylindrical part, 14-third bottom part, 15-third through-hole, 16-internal passage, 17-piezoelectric sheet, 18-fourth cylindrical part, 19-fourth bottom part, 20-fourth through-hole. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0040] The purpose of this invention is to provide a piezoelectric ultrasonic transducer and its manufacturing method, which can play a role in intravascular ultrasound imaging during interventional surgery, assist doctors in making precise interventions during the operation, and improve the success rate of the operation.

[0041] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Example 1

[0043] like Figures 1 to 13 As shown: This embodiment provides a piezoelectric ultrasonic transducer for use in vascular interventional ultrasound imaging. It is installed at the tip of a guidewire catheter. The outer diameter of the piezoelectric ultrasonic transducer is between 1 and 2 mm. It includes a flexible electronic circuit structure 2, a piezoelectric structure 3, and an external electrode structure 4 arranged sequentially from the inside out. The flexible electronic circuit structure 2 has a channel formed on its inner side for drug or guidewire passage. The piezoelectric structure 3 includes a piezoelectric substrate 6 and several piezoelectric pillars 7 arranged in an array. The piezoelectric pillars 7 are embedded in the piezoelectric substrate 6. The flexible electronic circuit structure... The structure 2 is provided with a number of electrode points 8, which correspond one-to-one with and are in contact with the piezoelectric pillars 7. Each electrode point 8 is connected to a first electrode lead 9. The other end of each first electrode lead 9 is connected to the external signal line, that is, connected to the positive electrode line. The external electrode structure 4 is in contact with each piezoelectric pillar 7, so that each piezoelectric pillar 7 has a common electrode and forms a common electrode surface. The external electrode structure 4 is connected to one end of the second electrode lead, and the other end of the second electrode lead is connected to the common signal line on the guide wire guide tube, that is, connected to the negative electrode line of the entire system.

[0044] Specifically, since the piezoelectric ultrasonic transducer ultimately operates in the blood, this embodiment also includes a permeation matching structure 5 for impedance matching. Polyurethane potting compound is used as the permeation matching structure 5. The permeation matching structure 5 is located outside the external electrode structure 4. The thickness of the permeation matching structure 5 is set according to one-quarter of the wavelength corresponding to the frequency set by the piezoelectric ultrasonic transducer.

[0045] This embodiment also includes a backing structure 1, which is located inside the flexible electronic circuit structure 2. The backing structure 1 is made of polyurethane foam and is cylindrical in shape. Openings are provided at both ends of the backing structure 1, and internal channels 16 in the backing structure 1 are used for drugs or guide wires to pass through. The polyurethane foam is lightweight and has a certain degree of rigidity, which is used to support the flexible electronic circuit structure 2, the piezoelectric structure 3, and the external electrode structure 4. Furthermore, the polyurethane foam has a fine and porous structure, which can absorb the reverse sound waves when the piezoelectric column 7 vibrates.

[0046] In the embodiment, the piezoelectric substrate 6 is made of silicone rubber, and the piezoelectric substrate 6 comprises a first cylindrical portion 10 and a first bottom portion 11, the first cylindrical portion 10 is embedded with a plurality of piezoelectric columns 7, the first bottom portion 11 is embedded with a plurality of piezoelectric columns 7, the first bottom portion 11 is arranged at one end of the first cylindrical portion 10, the other end of the first cylindrical portion 10 is open, and the first bottom portion 11 is provided with a first through hole 12.

[0047] In the embodiment, the piezoelectric column 7 is made of piezoelectric ceramic or piezoelectric quartz crystal, the polarization direction of the piezoelectric column 7 is the thickness direction, the polarization direction of the piezoelectric column 7 is consistent with the electric field direction, and the thickness of the piezoelectric column 7 is set according to the wavelength corresponding to the thickness resonance frequency of 5MHz to 10MHz set by the piezoelectric ultrasonic transducer. The thickness resonance frequency refers to that when the electric field direction of the piezoelectric column 7 is consistent with the polarization direction of the piezoelectric column 7, when an alternating voltage is applied to the two electrodes of the piezoelectric column 7, the piezoelectric column 7 vibrates in thickness due to the inverse piezoelectric effect, that is, the frequency of the applied alternating electric field is the thickness vibration frequency of the piezoelectric column 7.

[0048] In the embodiment, the flexible electronic circuit structure 2 comprises a second cylindrical portion and a second bottom portion, the second bottom portion is arranged at one end of the second cylindrical portion, the second bottom portion corresponds to the first bottom portion 11, the other end of the second cylindrical portion is open, and the second bottom portion is provided with a second through hole.

[0049] In the embodiment, the outer electrode structure 4 comprises a third cylindrical portion 13 and a third bottom portion 14, the third bottom portion 14 is arranged at one end of the third cylindrical portion 13, the third bottom portion 14 corresponds to the first bottom portion 11, the other end of the third cylindrical portion 13 is open, and the third bottom portion 14 is provided with a third through hole 15.

[0050] In the embodiment, the transparent matching structure 5 comprises a fourth cylindrical portion 18 and a fourth bottom portion 19, the fourth bottom portion 19 is arranged at one end of the fourth cylindrical portion 18, the fourth bottom portion 19 corresponds to the first bottom portion 11, the other end of the fourth cylindrical portion 18 is open, the fourth bottom portion 19 is provided with a fourth through hole 20, and the diameters of the first through hole 12, the second through hole, the third through hole 15 and the fourth through hole 20 are all the same as the size of the internal passage 16 in the backing structure 1.

[0051] The piezoelectric ultrasonic transducer of the embodiment is installed at the front end of the guide wire catheter, and is suitable for intravascular ultrasound imaging, and can perform omnidirectional ultrasound imaging on the blood vessel wall and the front end of the catheter. Compared with the conventional transducer, the present application combines the flexible electronic printing technology, greatly facilitates the leading out of the electrode wires of the piezoelectric column 7, and provides a new idea for complex array type piezoelectric ultrasonic transducers.

[0052] Embodiment two

[0053] The embodiment provides a manufacturing method of the piezoelectric ultrasonic transducer of the embodiment one, and comprises the following steps:

[0054] Step one, the piezoelectric sheet 17 is PZT piezoelectric ceramic sheet, the polarization direction is the thickness direction, and the polarization direction is consistent with the electric field direction, according to the actual application requirement of ultrasonic imaging in blood, the thickness resonance frequency range of the piezoelectric ultrasonic transducer is 5MHz to 10MHz, the piezoelectric sheet 17 with corresponding thickness is selected according to the thickness resonance frequency of the piezoelectric ultrasonic transducer, the piezoelectric sheet 17 is cut along the X direction and the Y direction in equal proportion, the cutting surface is the positive electrode surface, after cutting, the piezoelectric column 7 and the outer side of the outermost piezoelectric column 7 are filled with silicone rubber, forming the planar structure of the first cylindrical part 10 with the piezoelectric column 7 and the first bottom part 11 with the piezoelectric column 7;

[0055] Step two, according to the arrangement position of the piezoelectric column 7, the planar structure of the second cylindrical part and the second bottom part with adhesive capacity are printed by using a flexible electronic printing process:

[0056] Step three, the planar structure of the second cylindrical part is attached to the planar structure of the first cylindrical part 10 with the piezoelectric column 7, the second bottom part is attached to the first bottom part 11 with the piezoelectric column 7, each electrode point 8 in the flexible electronic circuit corresponds to each piezoelectric column 7 in the flexible piezoelectric composite structure in position and is electrically conductive, each electrode point 8 respectively leads out a first electrode lead 9, and each first electrode lead 9 is adhered to the flexible electronic circuit structure 2 through silicone rubber;

[0057] Step four, the planar structure of the first cylindrical part 10 and the planar structure of the second cylindrical part after being adhered are rolled into a cylindrical shape, and the second bottom part after being adhered is arranged at one end of the first cylindrical part 10 with the piezoelectric column 7;

[0058] Step five, the outer electrode structure 4 is covered outside the piezoelectric structure 3, one end of the second lead is connected with the outer electrode structure 4, and signal conduction can be completed through the second lead;

[0059] Step six, the backing structure 1 is arranged inside the flexible electronic circuit structure 2;

[0060] Step seven, the acoustic matching structure 5 is arranged outside the outer electrode structure 4.

[0061] In the specification, specific examples are applied to the principles and implementation modes of the application, and the above embodiment is only used to help understand the method and core idea of the application; meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation mode and application range can be changed. In view of the above, the content of the specification should not be understood as a limitation of the application.

Claims

1. A piezoelectric ultrasonic transducer, characterized in that: The device includes a flexible electronic circuit structure, a piezoelectric structure, and an external electrode structure arranged sequentially from the inside out. The flexible electronic circuit structure has a channel formed on its inner side for drugs or guide wires to pass through. The piezoelectric structure includes a piezoelectric substrate and a plurality of piezoelectric pillars. The plurality of piezoelectric pillars are embedded in the piezoelectric substrate. The flexible electronic circuit structure is provided with a plurality of electrode points, each of which corresponds to and contacts one of the piezoelectric pillars. Each of the electrode points is connected to a first electrode lead. The external electrode structure is in contact with each of the piezoelectric pillars and is connected to a second electrode lead. The piezoelectric substrate includes a first cylindrical portion and a first bottom portion. A plurality of piezoelectric posts are embedded in the first cylindrical portion and a plurality of piezoelectric posts are embedded in the first bottom portion. The first bottom portion is located at one end of the first cylindrical portion and the other end of the first cylindrical portion is open. The first bottom portion is provided with a first through hole. The flexible electronic circuit structure includes a second cylindrical part and a second bottom. The second bottom is disposed at one end of the second cylindrical part and corresponds to the first bottom. The other end of the second cylindrical part is open and the second bottom is provided with a second through hole. The external electrode structure includes a third cylindrical part and a third bottom. The third bottom is disposed at one end of the third cylindrical part and corresponds to the first bottom. The other end of the third cylindrical part is open, and the third bottom is provided with a third through hole. The polarization direction of the piezoelectric column is along its thickness direction, and the polarization direction of the piezoelectric column is consistent with the direction of the electric field.

2. The piezoelectric ultrasonic transducer according to claim 1, characterized in that: It also includes a transmissive matching structure, which is located outside the external electrode structure, and the thickness of the transmissive matching structure is set according to one-quarter of the wavelength corresponding to the frequency set by the piezoelectric ultrasonic transducer.

3. The piezoelectric ultrasonic transducer according to claim 2, characterized in that: It also includes a backing structure located inside the flexible electronic circuit structure, the backing structure being made of polyurethane foam.

4. The piezoelectric ultrasonic transducer according to claim 3, characterized in that: The piezoelectric substrate is made of silicone rubber.

5. The piezoelectric ultrasonic transducer according to claim 2, characterized in that: The permeable matching structure includes a fourth cylindrical part and a fourth bottom. The fourth bottom is disposed at one end of the fourth cylindrical part and corresponds to the first bottom. The other end of the fourth cylindrical part is open, and the fourth bottom is provided with a fourth through hole.

6. The piezoelectric ultrasonic transducer according to claim 3, characterized in that: The backing structure is cylindrical, with openings at both ends, and internal channels within the backing structure are used for the passage of drugs or guide wires.

7. The piezoelectric ultrasonic transducer according to claim 1, characterized in that: The piezoelectric column is made of piezoelectric ceramic or piezoelectric quartz crystal, and the thickness of the piezoelectric column is set according to the wavelength corresponding to the thickness resonance frequency of the piezoelectric ultrasonic transducer, which is set to 5MHz to 10MHz.

8. A method for manufacturing a piezoelectric ultrasonic transducer as described in any one of claims 1-7, characterized in that: Includes the following steps: Step 1: Select a piezoelectric sheet of appropriate thickness according to the thickness resonant frequency of the piezoelectric ultrasonic transducer. Cut the piezoelectric sheet proportionally along the X and Y directions, with the cutting surface being the positive electrode surface. After cutting, encapsulate silicone rubber between the piezoelectric pillars and on the outermost piezoelectric pillar to form a planar structure with a first cylindrical part containing piezoelectric pillars and a first bottom containing piezoelectric pillars. Step two: Based on the arrangement of the piezoelectric pillars, flexible electronic printing technology is used to print the planar structure of the second cylindrical section and the second bottom with adhesive capabilities. Step 3: Fit the planar structure of the second cylindrical part with the planar structure of the first cylindrical part with piezoelectric pillars, and fit the second bottom with the first bottom with piezoelectric pillars. Each electrode point in the flexible electronic circuit corresponds to the position of each piezoelectric pillar in the flexible piezoelectric composite structure and the electrical signal is conducted. Step 4: Roll the planar structures of the first cylindrical part and the second cylindrical part, which have been bonded together, into a cylindrical shape. The bonded second bottom and the first bottom with the piezoelectric post are set at one end of the first cylindrical part. Step 5: Cover the outside of the piezoelectric structure with the external electrode structure, and connect one end of the second lead to the external electrode structure. Step 6: Set a backing structure on the inside of the flexible electronic circuit structure; Step 7: Set a permeable matching structure on the outside of the external electrode structure.

Images