KR102249526B1 - Method for manufacturing ultrasonic probe and ultrasonic probe - Google Patents

Abstract

It provides a method of manufacturing an ultrasonic probe. The method of manufacturing the ultrasonic probe includes: forming a sacrificial layer on a substrate, forming a plurality of openings spaced apart from each other in the sacrificial layer, forming a piezoelectric part by growing a piezoelectric element in each of the plurality of openings, and sacrificial And removing the layer.

Description

TECHNICAL FIELD The manufacturing method of an ultrasonic probe and its apparatus TECHNICAL FIELD

The present disclosure relates to a method and apparatus for manufacturing an ultrasonic probe.

In general, an ultrasound diagnosis apparatus irradiates ultrasound into an object such as a person or an animal, detects an echo signal reflected from the object, displays a tomographic image of a tissue, etc. on a monitor, and provides information necessary for diagnosis of the object. In this case, the ultrasound diagnosis apparatus includes an ultrasound probe for transmitting ultrasound into an object and receiving an echo signal from within the object.

In addition, the ultrasonic probe is mounted therein and includes a transducer that converts an ultrasonic signal and an electrical signal to each other. In general, the transducer includes an assembly of a plurality of piezoelectric elements. Accordingly, the ultrasound diagnosis apparatus having these configurations generates an ultrasound image through an electrical signal by radiating ultrasound waves to an object to be examined, and converting the echo signal of the reflected ultrasound into an electrical signal.

The ultrasound diagnosis apparatus using such an ultrasound probe is usefully used for medical purposes such as detection of foreign substances in living organisms, measurement of injury degree, observation of tumors, and observation of fetuses through the above process.

In general, piezoelectric elements can be formed by physically separating the piezoelectric layer using a dicing equipment. More piezoelectric elements are needed to get a better image. However, it is practically difficult to manufacture a thin dicing blade. In addition, although a thin piezoelectric element is required for high frequency ultrasonic waves, it is difficult to manufacture a thin piezoelectric element, and there is a problem of high risk of damage during handling.

An embodiment provides a method of manufacturing an ultrasonic probe and an apparatus for forming a piezoelectric element in a growth manner.

A method of manufacturing an ultrasonic ultrasonic probe according to one type may include forming a sacrificial layer on a substrate; Forming a plurality of openings to be spaced apart from each other in the sacrificial layer; Forming a piezoelectric part by growing a piezoelectric element in each of the plurality of openings; And removing the sacrificial layer.

And, prior to forming the sacrificial layer, forming a first electrode unit by forming a plurality of first electrode elements to be spaced apart from each other; further comprising, the plurality of openings and the plurality of first electrode elements are one-to-one correspondence Can be.

In addition, the first electrode element may be a seed of the piezoelectric element.

In addition, the first electrode element may be a transparent conductive material.

In addition, the thickness of the sacrificial layer may be greater than the thickness of the piezoelectric part.

In addition, the sacrificial layer may be formed of a photosensitive material.

In addition, the photosensitive material may be of a positive type.

In addition, the method may further include forming a first electrode part by forming a first electrode element in the plurality of openings before growing the plurality of piezoelectric elements.

And, after growing the plurality of piezoelectric elements, forming a second electrode part by forming a second electrode element in each of the plurality of openings; may further include.

Further, it may further include forming a matching part on the second electrode part.

In addition, the forming of the matching unit may include forming each matching element on each second electrode element in the plurality of openings, and flattening the matching element.

In addition, the substrate may be a chip module substrate.

In addition, the substrate may include a sound absorbing material.

In addition, a spacing between neighboring piezoelectric elements among the plurality of piezoelectric elements may be 20 μm or less.

In addition, the thickness of at least one of the plurality of piezoelectric elements may be 200 μm or less.

In addition, the plurality of piezoelectric elements may be grown by a hydrothermal synthesis technique.

In addition, the plurality of piezoelectric elements may be grown at 200° C. or lower.

In addition, the plurality of openings may be arranged in one dimension or two dimensions.

On the other hand, the ultrasonic probe according to an embodiment, a substrate; an electrode unit including a plurality of electrode elements spaced apart in one or two dimensions on the substrate; And a piezoelectric unit including a plurality of piezoelectric elements disposed on each of the plurality of electrode elements, wherein each of the plurality of piezoelectric elements directly contacts each of the plurality of electrode elements.

In addition, a crystal structure of a region adjacent to the electrode element among the plurality of piezoelectric elements may be the same as the crystal structure of the electrode element.

Since the piezoelectric element is formed by a growth method, it is easy to adjust the thickness of the piezoelectric element.

In addition, since the size of the piezoelectric element is controlled using a photosensitive material, it is easy to adjust the size of the piezoelectric element.

Thus, an image with high resolution can be obtained, and an ultrasonic probe can be manufactured.

1 is a block diagram illustrating an ultrasound diagnosis apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating the ultrasonic probe shown in FIG. 1.
3 is a diagram schematically showing a physical configuration of the ultrasonic probe shown in FIG. 2.
4A and 4B are views showing an arrangement of piezoelectric elements in a piezoelectric unit according to an exemplary embodiment of the present invention.
5 to 11 are reference views illustrating a method of manufacturing an ultrasonic probe according to an embodiment of the present invention.
12 is an HR-TEM (High Resolution-Transmittion Electron Microscope) photograph when a piezoelectric material is grown on a seed layer according to an exemplary embodiment.
13 is a picture of a high resolution-transmittion electron microscope (HR-TEM) when a piezoelectric material and a substrate are bonded with an adhesive.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numbers, and redundant descriptions thereof are omitted. I will do it.

In the present specification, the "subject" may include a human or an animal, or a part of a human or animal. For example, the subject may include organs such as liver, heart, uterus, brain, breast, abdomen, or blood vessels. In addition, in the present specification, the "user" may be a medical expert, such as a doctor, a nurse, a clinical pathologist, a medical imaging expert, and the like, and may be a technician who repairs a medical device, but is not limited thereto.

1 is a block diagram illustrating an ultrasound diagnosis apparatus according to an exemplary embodiment of the present invention. Referring to FIG. 1, the ultrasound diagnosis apparatus 100 is applied by an ultrasound probe 110 and an ultrasound probe 110 that transmits and receives ultrasound. A signal processing unit 120 that processes the generated signal to generate an image, a display unit 130 that displays an image, a user input unit 140 that receives a user command, a storage unit 150 in which various information is stored, and an ultrasound diagnosis apparatus 100 ) And a control unit 160 that controls the overall operation.

The ultrasonic probe 110 is a device that transmits ultrasonic waves to an object and receives an echo signal of ultrasonic waves reflected from the object, and a detailed description will be described later.

The signal processing unit 120 generates an ultrasound image by processing ultrasound data generated by the ultrasound probe 110. The ultrasound image is a B mode image representing the magnitude of an ultrasound echo signal reflected from an object in brightness, and a Doppler mode image representing an image of an object moving using the Doppler effect in a spectral form. , An M mode image representing the motion of an object over time at a certain position, an elastic mode image representing the difference in response between when compression is applied to the object and not applied, and a Doppler effect. effect) to express the speed of the moving object in color. Since the ultrasound image generation method applies the currently available ultrasound image generation method, a detailed description thereof will be omitted. Accordingly, the ultrasound image according to an embodiment of the present invention may include an image of a mode dimension such as 1D, 2D, 3D, 4D.

The display unit 130 displays information processed by the ultrasound diagnosis apparatus 100. For example, the display unit 130 may display an ultrasound image generated by the signal processing unit 120 and may display a GUI for requesting a user's input.

The display unit 130 includes a liquid crystal display, a thin film transistor-liquid crystal display, an organic light-emitting diode, a flexible display, and a 3D display. display) and an electrophoretic display, and the ultrasound diagnosis apparatus 100 may include two or more display units 130 according to implementation types.

The user input unit 140 refers to a means for a user to input data for controlling the ultrasound diagnosis apparatus 100. The user input unit 140 may include a keypad, a mouse, a touch panel, and a trackball. The user input unit 140 is not limited to the illustrated configuration, and may further include various input means such as a jog wheel and a jog switch.

Meanwhile, the touch panel can detect not only a real touch of a pointer to the screen, but also a proximity touch of the pointer within a predetermined distance from the screen. In the present specification, a pointer refers to a tool for touching a specific part of the touch panel or touching a specific part of the touch panel, and examples thereof include a stylus pen or a part of a body such as a finger.

In addition, the touch panel may be implemented as a touch screen that forms a layer structure with the display unit 130 described above, and the touch screen is a contact type capacitive type, a pressure type resistive layer type, and infrared detection. It can be implemented in various ways, such as a method, a surface ultrasonic conduction method, an integral tension measurement method, and a piezo effect method. Since the touch screen performs the functions of the user input unit 140 as well as the display unit 130, its utilization is high.

Although not shown in the drawings, the touch panel may include various sensors inside or near the touch panel to sense a touch. As an example of a sensor for the touch panel to sense a touch, there is a tactile sensor. The tactile sensor refers to a sensor that detects contact with a specific object to a level that a person feels it or more. The tactile sensor can detect various information such as roughness of a contact surface, hardness of a contact object, and temperature of a contact point.

Also, as an example of a sensor for the touch panel to sense a touch, there is a proximity sensor. The proximity sensor refers to a sensor that detects the presence or absence of an object approaching a predetermined detection surface or an object existing in the vicinity using the force of an electromagnetic field or infrared rays without mechanical contact. Examples of the proximity sensor include a transmission type photoelectric sensor, a diffuse reflection type photoelectric sensor, a mirror reflection type photoelectric sensor, a high frequency oscillation type proximity sensor, a capacitive type proximity sensor, a magnetic type proximity sensor, an infrared proximity sensor, and the like.

The storage unit 150 stores various types of information processed by the ultrasound diagnosis apparatus 100. For example, the storage unit 150 may store medical data related to diagnosis of an object such as an image, and may store an algorithm or program performed in the ultrasound diagnosis apparatus 100.

The storage unit 150 includes a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (SD, XD memory, etc.), and RAM (RAM). , Random Access Memory) Among SRAM (Static Random Access Memory), ROM (ROM, Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read-Only Memory) magnetic memory, magnetic disk, optical disk It may include at least one type of storage medium. In addition, the ultrasound diagnosis apparatus 100 may operate a web storage or a cloud server that performs a storage function of the storage unit 150 on the web.

The controller 160 overall controls the operation of the ultrasound diagnosis apparatus 100. That is, the control unit 160 may control operations of the ultrasonic probe 110, the signal processing unit 120, and the display unit 130 shown in FIG. 1. For example, the controller 160 may control the signal processing unit 120 to generate an image using a user command input through the user input unit 140 or a program stored in the storage unit 150. In addition, the control unit 160 may control the image generated by the signal processing unit 120 to be displayed on the display unit 130.

2 is a block diagram illustrating the ultrasound probe 110 shown in FIG. 1. Referring to FIG. 2, an ultrasonic probe 110 is a device capable of generating ultrasonic data by transmitting ultrasonic waves to an object 10 and receiving an echo signal reflected from the object 10. It may include 220 and a receiver 230.

The transmission unit 210 supplies a driving signal to the piezoelectric unit 220. The transmission unit 210 may include a pulse generator 212, a transmission delay unit 214, and a pulser 216.

The pulse generator 212 generates a rate pulse for forming a transmission ultrasonic wave according to a predetermined pulse repetition frequency (PRF). The transmission delay unit 214 applies a delay time for determining transmission directionality to a rate pulse generated by the pulse generation unit 212. Each of the rate pulses to which the delay time is applied corresponds to the plurality of piezoelectric elements 222 included in the piezoelectric unit 220, respectively. The pulser 216 applies a driving signal (or driving pulse) to the piezoelectric unit 220 at a timing corresponding to each rate pulse to which a delay time is applied.

The piezoelectric unit 220 transmits ultrasonic waves to the object 10 according to the driving signal supplied from the transmitter 210 and receives an echo signal of the ultrasonic waves reflected from the object 10. The piezoelectric unit 220 may include a plurality of piezoelectric elements 222 that convert electrical signals into (or vice versa) acoustic energy.

The receiving unit 230 processes a signal received from the piezoelectric unit 220 to generate ultrasonic data, and the receiving unit 230 is an amplifier 232, an ADC 234 (analog digital converter, analog digital converter), a reception delay unit 236, and a summing unit 238 may be included.

The amplifier 232 amplifies the signal received from the piezoelectric unit 220, and the ADC 234 converts the amplified signal to analog-digital. The reception delay unit 236 applies a delay time for determining reception directionality to the digitally converted signal. The summing unit 238 generates ultrasound data by summing the signals processed by the reception delay unit 236. The reflection component from the direction determined by the reception directivity may be emphasized by the summing process of the summing unit 238.

Among the ultrasonic probes 110, the transmitter 210 and the receiver 230 may be formed of at least one chip on one substrate 240. Here, the substrate 240 may be made of a Si, ceramic, or polymer-based material. Alternatively, the substrate 240 may be formed of a sound-absorbing material that absorbs ultrasonic waves. Each of the blocks in the transmitter 210 and the receiver 230 may be formed as one chip, two or more blocks may be formed as one chip, and one chip corresponds to one piezoelectric element 222. Can be formed. Thus, the substrate 240 including at least one of the transmitter 210 and the receiver 230 is referred to as a chip module substrate 240. The chip module substrate 240 refers not only to the substrate 240 including all the chips included in the ultrasonic probe 110, but also the substrate 240 including some chips included in the ultrasonic probe.

Meanwhile, the ultrasonic probe 110 may further include a part of the signal processing unit 120, a part of the display unit 130, and a part of the user input unit 140 in addition to the transmitting unit 210 and the receiving unit 230. Of course.

3 is a diagram schematically showing the physical configuration of the ultrasonic probe 110 shown in FIG. 2. As shown in FIG. 3, the ultrasonic probe 110 includes a chip module substrate 240, a piezoelectric part 220 that converts ultrasonic waves and electrical signals to each other while vibrating, and between the piezoelectric part 220 and the chip module substrate 240. The first electrode unit 250 and the piezoelectric unit 220 that electrically connect the piezoelectric unit 220 and the chip module substrate 240 are disposed to face the first electrode unit 250 and disposed therebetween. The second electrode unit 260 may be included. As described above, the chip module substrate 240 refers to a substrate 240 including at least one chip that processes an electrical signal. For example, at least one chip for performing operations of the receiving unit 230 and the transmitting unit 210 is formed on the chip module substrate 240. The chip module substrate 240 may be an application specific integrated circuit (ASIC), but is not limited thereto.

The piezoelectric unit 220 includes a plurality of piezoelectric elements 222 that convert electrical signals and ultrasonic waves to each other while vibrating. The plurality of piezoelectric elements 222 may be arranged to be spaced apart from each other. The plurality of piezoelectric elements 222 according to an embodiment may be formed using a growth technique. A method of manufacturing the piezoelectric element 222 will be described later. The piezoelectric element 222 may be formed of a material that causes a piezoelectric phenomenon. The above materials include at least one of ZnO, AlN, PZT (PbZrTiO3), PLZT (PbLaZrTiO3), BT (BaTiO3), PT (PbTiO3), PMN-PT (Pb(Mg1/3Nb2/3)O3-PbTiO3), etc. can do. The spacing d between the piezoelectric elements 222 adjacent among the plurality of piezoelectric elements 222 may be 20 μm or less, and the thickness t of at least one of the plurality of piezoelectric elements 222 may be 200 μm or less.

The first electrode unit 250 electrically connects the piezoelectric unit 220 and the chip module substrate 240. The first electrode unit 250 may include a plurality of first electrode elements 252 arranged to be spaced apart from each other while connecting each of the piezoelectric elements 222 to the chip module substrate 240. Each of the first electrode elements 252 may electrically connect each of the piezoelectric elements 222 to the chip module substrate 240. In addition, the first electrode element 252 may be formed of a conductive material. In particular, the first electrode element 252 may be formed of a metal and may be a seed layer of the piezoelectric element 222.

The second electrode part 260 may be disposed to face the first electrode part 250 with the piezoelectric part 220 interposed therebetween. The second electrode unit 260 may also include a plurality of second electrode elements 262 arranged to be spaced apart from each other. The second electrode part 260 forms an electric field in the piezoelectric part 220 together with the first electrode part 250. For example, a voltage of a predetermined size may be applied to the first electrode unit 250, and the second electrode unit 260 may be grounded. The second electrode part 260 may also be formed of a conductive material, and in addition to metal materials, carbon nanostructures such as CNT (carbone nanotube) and graphene, polypyrrole, polyaniline, and polyacetylene ), polythiophene, polyphnylene vinylene, polyphenylene sulfide, poly p-phenylene, polyheterocycle vinylene. Dispersion of many conductive polymers, metal oxides such as ITO (indium tin oxide), AZO (Aluminium Zinc Oxide), IZO (Indium Zinc Oxide), SnO2 (Tin oxide) or In2O3, and metal nanoparticles such as Al, Cu, Au, Ag It may be formed as a thin film or the like.

In addition, the ultrasound probe 110 includes a sound absorbing unit 280 that absorbs ultrasound transmitted in a direction opposite to the object. The sound absorbing unit 280 supports the chip module substrate 240 from the rear surface of the chip module substrate 240 and is transmitted to the rear of the piezoelectric unit 220 to absorb ultrasonic waves that are not directly used for inspection or diagnosis. In FIG. 3, the sound-absorbing part 280 is formed as a separate device from the chip module substrate 240, but this is for convenience of description and is not limited thereto. The substrate 240 of the chip module substrate 240 may be formed of a sound absorbing material. Thus, the chip module substrate 240 may perform the function of the sound absorbing unit 280.

In addition, the ultrasonic probe 110 may further include a matching unit 270 that matches the acoustic impedance of the ultrasonic wave generated by the piezoelectric unit 220 with the acoustic impedance of the object. The matching unit 270 is disposed on the front surface of the piezoelectric unit 220 and gradually changes the acoustic impedance of the ultrasonic waves generated by the piezoelectric unit 220 to make the acoustic impedance of the ultrasonic waves close to the acoustic impedance of the object. Here, the front surface of the piezoelectric unit 220 may mean a surface closest to the object among the surfaces of the piezoelectric unit 220 while ultrasonic waves are emitted to the object, and the rear surface may mean a surface opposite to the front surface.

The matching unit 270 may also include a plurality of matching elements 272 disposed on each of the piezoelectric elements 222. However, it is not limited thereto. In the matching unit 270, a plurality of piezoelectric elements 222 may be grouped to form one matching element 272. The matching part 270 may be formed of a single layer, but may have a multilayer structure.

In addition, the ultrasonic probe 110 may further include an acoustic lens (not shown) that focuses the ultrasonic waves. The acoustic lens is disposed on the front surface of the piezoelectric unit 220 and serves to focus ultrasonic waves generated by the piezoelectric unit 220. The acoustic lens may be formed of a material such as silicone rubber having an acoustic impedance close to the object. In addition, the shape of the acoustic lens may be convex in the center or may be flat. The acoustic lens may have various shapes according to the designer's design.

4A and 4B are views showing an arrangement of piezoelectric elements in a piezoelectric unit according to an exemplary embodiment of the present invention. As shown in FIG. 4A, the piezoelectric elements 222 may be one-dimensionally arranged in the longitudinal direction L of the piezoelectric part 220 on the front surface of the electrode element. This can be referred to as a one-dimensional piezoelectric part. The one-dimensional piezoelectric part may be a linear array or a curved array. The arrangement type can be set in various ways according to the intention of the designer. The one-dimensional piezoelectric part is easy to manufacture and thus has the advantage of low manufacturing cost. However, the 1D piezoelectric part has difficulty in realizing a 3D stereoscopic image.

As shown in FIG. 4B, the piezoelectric elements 222 may be two-dimensionally arranged in a direction perpendicular to the longitudinal direction L as well as the longitudinal direction L of the piezoelectric unit 220. This can be referred to as a two-dimensional piezoelectric part. The 2D piezoelectric part may be a linear array or a curved array. The arrangement type can be set in various ways according to the intention of the designer. Here, the 2D piezoelectric unit appropriately delays the input time of signals input to each piezoelectric element 222 to transmit the ultrasonic wave to the object along an external scan line. Accordingly, a 3D image is obtained by using a plurality of the echo signals. Meanwhile, as the number of piezoelectric elements 222 increases, a clearer ultrasound image may be obtained.

5 to 11 are reference views illustrating a method of manufacturing an ultrasonic probe according to an embodiment of the present invention. (i) is a perspective view illustrating a method of manufacturing an ultrasonic probe, and (ii) is a cross-sectional view illustrating a method of manufacturing an ultrasonic probe.

First, as shown in FIG. 5, the first electrode part 250 is formed on the substrate 240. The substrate 240 may be a chip module substrate 240. The first electrode unit 250 may be formed on a region of the substrate 240 in which electrical connection is required. The first electrode part 250 may be formed of a plurality of first electrode elements 252 spaced apart from each other. For example, the first electrode unit 250 may be formed by coating a conductive material (ie, the first electrode element 252) on a region requiring electrical connection among the substrate 240 using a mask. The first electrode part 250 may be formed by coating a conductive material on 240 and then etching a region other than a region requiring electrical connection using a mask. The plurality of first electrode elements 252 may be arranged in one dimension or two dimensions, or may be arranged in a matrix type. In the drawing, a plurality of first electrode elements 252 arranged in two dimensions are illustrated, but the present invention is not limited thereto.

In addition, as shown in FIG. 6, a sacrificial layer 280 may be formed on the substrate 240 on which the first electrode part 250 is formed. The sacrificial layer 280 may be formed of a photosensitive material. As the photosensitive material, an organic material having a positive type characteristic in which a portion receiving light is removed, for example, a positive type photoresist may be used. For example, the photosensitive material may be formed of a solid powder having a property of chemically reacting with light and a volatilized solvent. The viscosity of the photosensitive material can be adjusted by adjusting the ratio of solid and solvent. In addition, a surfactant may be included in the photosensitive material. The above-described surfactant allows the photosensitive material to have a uniform thickness. The thickness of the sacrificial layer 280 may be equal to the sum of the thicknesses of the first electrode part 250, the piezoelectric part 220, the second electrode part 260, and the matching part 270.

In addition, as shown in FIG. 7, a plurality of openings h may be formed in the sacrificial layer 280 to be spaced apart from each other. For example, when the photosensitive material is of a positive type, an exposure mask exposing a region of the sacrificial layer 280 in which the first electrode unit 250 is disposed is positioned on the sacrificial layer 280. Then, exposure is performed through an exposure mask. Ultraviolet light is generally, but is not limited thereto, and an electron beam, an ion beam, or an X-ray may be used. The exposure amount may be an amount in which the entire thickness of the photosensitive material can be removed by reacting with the irradiated light. When the sacrificial layer 280 is removed by performing exposure, the sacrificial layer 280 having a plurality of openings h disposed to be spaced apart from each other as illustrated in FIG. 7 may be formed. When the first electrode part 250 is transparent, the light passing through the sacrificial layer 280 and incident on the first electrode part 250 is again incident on the sacrificial layer 280, so that the exposure amount and exposure time can be shortened. .

Although the photosensitive material has been described as a positive type, it is not limited thereto. The photosensitive material may be a negative type, or when the photosensitive material is a negative type, the sacrificial layer 280 that does not overlap with the first electrode unit 250 is exposed to form a sacrificial layer 280 having an opening h. I can.

In addition, in an exemplary embodiment, it has been described that the sacrificial layer 280 having a plurality of openings h is formed after the first electrode part 250 is formed, but the present invention is not limited thereto. After forming the sacrificial layer 280 having a plurality of openings h, the first electrode part 250 may be formed. That is, after forming the sacrificial layer 280 having a plurality of openings h using an exposure mask and light, the first electrode part 250 may be deposited in the opening h. Since the spacing between the openings h can be adjusted using light, it is easy to adjust the spacing between the openings h. Since the gap between the openings h means the spacing between the piezoelectric elements 222, it is easy to adjust the spacing of the piezoelectric elements 222.

Then, as shown in FIG. 8, a plurality of piezoelectric elements 222 are grown in the opening h. The plurality of piezoelectric elements 222 may be grown using a hydrothermal synthesis technique. For example, the substrate 240 of FIG. 7 is immersed in a chamber containing an aqueous solution containing a piezoelectric material. Then, the piezoelectric element 222 may be grown in the opening h by a hydrothermal synthesis technique. In this case, the temperature in the chamber may be 200°C or less. When the first electrode unit 250 is formed of a metal material, the metal material may become a seed layer of the piezoelectric element 222, so that the piezoelectric element 222 can be easily grown on the first electrode unit 250. have. When the electrode portion is not formed of a metal material, the piezoelectric element 222 may be grown after forming a metal material as a seed layer in the opening h.

In addition, as shown in FIG. 9, the second electrode part 260 and the matching part 270 may be sequentially formed on the piezoelectric part 220. The second electrode part 260 may be formed by forming one conductive material layer on the plurality of piezoelectric elements 222, and the matching part 270 is formed by forming the matching elements 272 one by one on the plurality of conductive material layers. Can be formed. It goes without saying that the second electrode part 260 on the second electrode part 260 may also be formed of the same material as the first electrode part 250.

Then, as illustrated in FIG. 10, the matching unit 270 may be flattened, and as illustrated in FIG. 11, the sacrificial layer 280 may be removed. The sacrificial layer 280 may be removed by exposing the sacrificial layer 280 to a developer.

Although not shown in the drawing, an acoustic lens may be stacked on the matching unit 270.

Since the spacing between the piezoelectric elements 222 can be adjusted using light, the spacing of the piezoelectric elements 222 can be more finely adjusted, and the thickness of the piezoelectric elements 222 can be easily reduced by growing the piezoelectric elements 222 Can be adjusted.

As described above, since the piezoelectric material is directly grown on the electrode portion or the seed layer (hereinafter referred to as “seed layer”), the piezoelectric material according to the exemplary embodiment may have a crystal structure. For example, a region of the piezoelectric material adjacent to the seed layer may have the same crystal structure as the seed layer. Thus, there may be no interface between the piezoelectric material and the seed layer. Alternatively, the piezoelectric material may have a crystal structure similar to that of the seed layer even though dislocation occurs between the piezoelectric material and the seed layer due to different particles of the piezoelectric material and the grain of the seed layer.

However, when bonding a piezoelectric material and another layer, for example, a chip module substrate, with an adhesive to create an ultrasonic probe, an adhesive layer exists between the piezoelectric material and the chip module substrate, and the piezoelectric material and the chip module substrate are determined. The structures are not related to each other.

In order to confirm the crystal structure according to the direct growth of the piezoelectric material, SRO was used as the seed layer, and PZT (PbZrTiO3) was used as the piezoelectric material. Then, a piezoelectric material was grown on the sheath layer. 12 is an HR-TEM (High Resolution-Transmittion Electron Microscope) photograph when a piezoelectric material is grown on a seed layer according to an exemplary embodiment. As shown in FIG. 12, the crystal structure of the piezoelectric element was almost similar to that of the seed layer so that the interface between the seed layer and the piezoelectric element hardly appeared.

13 is a picture of a high resolution-transmittion electron microscope (HR-TEM) when a piezoelectric material and a substrate are adhered with an adhesive. As shown in FIG. 13, it can be seen that there is an adhesive between the piezoelectric material and the substrate, and the crystal structure of the piezoelectric element and the crystal structure of the substrate are irrelevant. Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention. Since the present invention can apply various transformations and have various embodiments, specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all conversions, equivalents, and substitutes included in the spirit and scope of the present invention.

100: ultrasonic diagnostic device 110: ultrasonic probe
210: transmitting unit 220: piezoelectric unit
222: piezoelectric element 230: receiving unit
240: chip module substrate 250: first electrode unit
252: first electrode element 260: second electrode unit
262: second electrode element 270: matching unit
272: matching element 280: sound absorption unit
290: sacrificial layer

Claims (20)

Forming a sacrificial layer on the substrate;
Forming a plurality of openings to be spaced apart from each other in the sacrificial layer;
Forming a piezoelectric part by growing each of a plurality of piezoelectric elements in each of the plurality of openings;
Forming a second electrode portion by forming each of a plurality of second electrode elements on each of the piezoelectric elements in the plurality of openings;
Forming a matching portion by forming each of a plurality of matching elements on each of the second electrode elements in the plurality of openings; And
Removing the sacrificial layer; Method of manufacturing an ultrasonic probe comprising a. The method of claim 1,
Before forming the sacrificial layer, forming a first electrode part by forming a plurality of first electrode elements to be spaced apart from each other; further comprising,
The method of manufacturing an ultrasonic probe in which the plurality of openings and the plurality of first electrode elements correspond one-to-one. The method of claim 2,
The method of manufacturing an ultrasonic probe in which the first electrode element becomes a seed of the piezoelectric element. The method of claim 2,
The first electrode element is a method of manufacturing an ultrasonic probe of a transparent conductive material. The method of claim 1,
The thickness of the sacrificial layer is a method of manufacturing an ultrasonic probe larger than the thickness of the piezoelectric part. The method of claim 1,
The sacrificial layer is a method of manufacturing an ultrasonic probe formed of a photosensitive material. The method of claim 6,
The photosensitive material is a method of manufacturing an ultrasonic probe of a positive type. The method of claim 1,
Forming a first electrode portion by forming a first electrode element in the plurality of openings before growing the plurality of piezoelectric elements. delete delete The method of claim 1,
The step of forming the matching part,
The method of manufacturing an ultrasonic probe further comprising a step of flattening the plurality of matching elements. The method of claim 1,
The substrate is a method of manufacturing an ultrasonic probe that is a chip module substrate. The method of claim 1,
The substrate,
A method of manufacturing an ultrasonic probe containing a sound absorbing material. The method of claim 1,
The spacing between neighboring piezoelectric elements among the plurality of piezoelectric elements,
A method of manufacturing an ultrasonic probe of 20 μm or less. The method of claim 1,
A method of manufacturing an ultrasonic probe having a thickness of at least one of the plurality of piezoelectric elements is 200 μm or less. The method of claim 1,
The plurality of piezoelectric elements,
A method of manufacturing an ultrasonic probe grown by a hydrothermal synthesis technique. The method of claim 1,
The plurality of piezoelectric elements,
A method of manufacturing an ultrasonic probe grown below 200°C. The method of claim 1,
The plurality of openings,
A method of manufacturing an ultrasonic probe arranged in one or two dimensions. delete delete

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