JP3206959B2 - Ultrasonic transducer manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic transducer used for an ultrasonic endoscope for medical use and the like.
More specifically, the present invention relates to a method for manufacturing an acoustic matching layer / back load material and a method for electrically connecting transducers.

[0002]

2. Description of the Related Art An ultrasonic endoscope / flaw detector scans an ultrasonic beam oscillated from an ultrasonic transducer and re-evaluates ultrasonic waves reflected by a built-in inner wall / lesion or a structural defect in a material. The information is received by the ultrasonic transducer and processed to obtain information on a defect in the object and an ultrasonic tomographic image.

[0003] The above-mentioned ultrasonic transducer is generally constituted by using piezoelectric ceramics, and a high-frequency voltage pulse is applied to the piezoelectric ceramics using electrodes formed on the surface thereof to rapidly deform the piezoelectric ceramics. And oscillate an ultrasonic pulse. This piezoelectric ceramic has a large difference with the acoustic impedance of the living body,
Ultrasonic waves are reflected at the interface between the two, causing loss. In order to absorb this difference and reduce acoustic loss, an acoustic matching layer made of a resin material or the like is provided on the acoustic emission surface side of the piezoelectric ceramic.

FIGS. 22 and 23 show the structure of a general ultrasonic transducer. FIG. 22 shows a case in which the acoustic matching layer 51 is a single layer, and FIG. 23 shows a case in which the acoustic matching layer 51 is a multilayer. The acoustic matching layer 51 is generally made of a resin plate or a material obtained by mixing a powder of a ceramic or the like into a resin and processed into a plate shape. For example, JP-A-60-112399
In the invention described in Japanese Patent Application Laid-Open Publication No. H11-260, the plate-shaped acoustic matching layer 51 is formed, and then the piezoelectric ceramics 5 are formed.
2

[0005] A back load member 53 is provided on the opposite side of the acoustic emission surface of the piezoelectric ceramics 52 to prevent the oscillated ultrasonic wave from leaking from the back of the ultrasonic transducer and to prevent the oscillated ultrasonic wave from leaking from the back of the ultrasonic transducer. Noise is prevented. The back load material 53 is generally made of a resin plate or a material obtained by mixing a resin or a powder of ceramic or metal into a plate, and is bonded to the piezoelectric ceramic 52 in the same manner as the acoustic matching layer 51. And make it.

[0006]

However, in the above-mentioned prior art, when the bonding step of the piezoelectric element, the acoustic matching layer, and the back load material is performed, the adhesive is applied to the surface other than the bonding surface, for example, the surface for electrical connection. There is a problem that it adheres to the electrode or the like. In order to prevent the adhesion, generally, the amount of the adhesive is controlled, or the adhered adhesive is wiped before curing.

[0007] When controlling the amount of the adhesive, it is important to control the amount of the adhesive in a very small amount. That is, if the amount of the adhesive is very small, the adhesive will adhere to unnecessary portions. Further, if the amount is extremely small, there is a disadvantage that the adhesive strength is reduced.

Further, since the oscillation frequency of the ultrasonic transducer for an ultrasonic endoscope is on the order of several MHz to several tens of MHz, one of the wavelengths of generally used ultrasonic waves is used.
The acoustic matching layer having a thickness of about ４ is a thin plate having a thickness of several tens of μm because the acoustic velocity of the resin is usually 2500 to 3000 m / s. For this reason, when the step of wiping the adhesive is adopted, the piezoelectric element and the acoustic matching layer are both thin plates, so that there is a disadvantage that the displacement of the joined parts occurs during the operation.

Accordingly, the present invention has been developed in view of the above-mentioned drawbacks in the prior art, and has a high performance ultrasonic transducer capable of easily forming an acoustic matching layer and a back load material using resin. The purpose of the present invention is to provide a manufacturing method.

[0010]

SUMMARY OF THE INVENTION The present invention relates to an ultrasonic transducer manufacturing method for manufacturing an ultrasonic transducer in which an acoustic matching layer, a piezoelectric element and a back load material are joined, and an acoustic matching layer for the piezoelectric element. A coating step of coating the surface other than the formation surface with a protective resin, a coating and curing step of applying and curing a resin material to be an acoustic matching layer to the outside of the formation region, and removing an unnecessary portion and the protective resin from the cured resin. And a removing step of removing.

Further, in the method for manufacturing an ultrasonic transducer for manufacturing an ultrasonic transducer in which an acoustic matching layer, a piezoelectric element, and a back load material are joined, the surface of the piezoelectric element other than the surface on which the back load material is formed is covered with a protective resin. A coating step, a coating / curing step of applying and curing a resin material to be a back load material to an area outside the formation area, and a removing step of removing an unnecessary portion and a protective resin from the cured resin material. An ultrasonic transducer manufacturing method.

[0012] Further, the acoustic matching layer, the piezoelectric element, and the back load member are formed by joining the acoustic matching layer, and an electrode terminal of a front surface electrode is provided other than the joint surface between the acoustic matching layer of the piezoelectric element and the back load material. In an ultrasonic transducer manufacturing method for manufacturing an ultrasonic transducer, a coating step of coating a surface other than the surface on which the electrode terminal is formed with a protective resin, and a coating / curing method in which the conductive material of the electrode terminal is applied to the outside of the formation region and cured. A method for manufacturing an ultrasonic transducer, comprising: a step of removing an unnecessary portion and a protective resin from the cured conductive material.

According to a fourth aspect of the present invention, in the method for manufacturing an ultrasonic transducer according to the first aspect, the covering step is a step of covering all parts other than a surface on which an acoustic matching layer is formed. This is a method for manufacturing an acoustic transducer. Furthermore, the invention described in claim 5 is the same as the claim 2
In the ultrasonic transducer manufacturing method described above, the coating step is a step of coating all parts other than the surface on which the back load material is formed.

FIGS. 1 to 5 are conceptual diagrams showing the manufacturing process of the present invention. A surface electrode 14 is formed on the piezoelectric element 13. Of the entire surface of the piezoelectric element 13, a portion other than the surface on which any of the resin layers of the acoustic matching layer, the back load material, and the electrode terminal is formed is covered with the protective resin 3. Thereafter, a target resin (uncured / liquid) 2 is applied and cured. Cut out the part 1 of the cured resin that comes out of the piezoelectric element.
Removed by cutting or the like. After or simultaneously with the removal of the resin layer, the protective resin 3 is removed by dissolving or peeling, thereby forming a target resin layer 8 such as an acoustic matching layer, a back load material, and an electrode terminal.

Through the above steps, any portion of the acoustic matching layer, the back load material, and the electrode terminal other than the surface on which the resin layer is formed can be effectively protected. Therefore, it is possible to prevent the adhesive from adhering to unnecessary parts and to prevent the adhesive strength from decreasing.

[0016]

Embodiment 1 FIGS. 6 to 11 show this embodiment, FIGS. 6 to 10 are process drawings, and FIG. 11 is a sectional view showing a modification. A surface electrode 14 is formed on the piezoelectric element 13. The surface electrode 14 extends to the side surface of the piezoelectric element 13. In addition, an acrylic UV-curable water-soluble resin as a protective resin, an ultraviolet irradiation device for curing the protective resin, a liquid epoxy-based resin as a material for the acoustic matching layer, and an epoxy resin coating device (all shown) No).

The step of forming the acoustic matching layer will be described below. After covering the portion of the entire surface of the piezoelectric element 13 other than the surface 9 on which the acoustic matching layer is formed with a liquid acrylic ultraviolet-curable water-soluble resin, ultraviolet light is irradiated from an ultraviolet irradiation device (not shown). By curing, the piezoelectric element 13
The protective resin layer 3 is coated with a water-soluble resin.

After that, a liquid resin as a material of the acoustic matching layer is applied to the piezoelectric element 13 and cured to form the resin layer 4. Dipping was used as a coating method. With respect to a flat piezoelectric element plate, when a resin of several thousands cps class is used according to dipping, a smooth resin layer having a thickness of several tens of μm can be easily formed. The thickness of the resin layer can be strictly and easily controlled by controlling the pulling speed of the piezoelectric element plate. The portion of the cured resin that has come out of the piezoelectric element is removed by cutting or cutting. After or simultaneously with the completion of the resin layer removal processing, the protective resin is dissolved and removed by washing with water or alcohol to form the acoustic matching layer 5.

In this embodiment, by performing the above steps, the acoustic matching layer is formed in a state where the surface other than the surface on which the acoustic matching layer is formed is effectively protected.

According to this embodiment, since the piezoelectric element and the surface electrode are exposed in the portion protected by the protective resin after the removal of the protective resin, post-processing such as joining and wiring can be directly performed.

By using the same process as in the present embodiment, changing the liquid resin that is the material of the acoustic matching layer and performing the dipping process a plurality of times, the surplus resin and the protective resin are removed. Multilayer acoustic matching layer 5 as shown in FIG.
It is also possible to form As a method of applying the resin layer serving as the acoustic matching layer, other methods such as spraying and printing can be used. Similarly, as the liquid resin that is the material of the acoustic matching layer, a urethane-based resin can be used. In this embodiment, the resin layer is formed by the coating method. However, it is apparent that the present invention can be applied to a method of bonding the resin layer formed to a predetermined thickness with an adhesive.

[0022]

Embodiment 2 FIGS. 12 to 15 are process diagrams showing this embodiment. The basic configuration is the same as that of the first embodiment. The same components are denoted by the same reference numerals and the description thereof will be omitted, and only the differences will be described. In this embodiment, silicone rubber is used as the protective resin. After covering the portion of the entire surface of the piezoelectric element 13 other than the surface 9 on which the acoustic matching layer is formed with liquid silicone rubber, the silicone rubber is cured by being left at room temperature or heated in a high-temperature bath. 13 is coated with silicone rubber as the protective resin tank 3.

The applied resin does not adhere to the surface of the silicone rubber because the wettability of the silicone rubber is low, and the resin bath is formed only on the forming surface 9. The silicone rubber is removed by dissolving the silicone rubber by ultrasonic cleaning in a silicone dissolving agent, or by mechanically peeling off using a silicone rubber having a high mold release property.

According to this embodiment, as compared with the first embodiment, since the resin does not adhere to the surface of the silicone rubber, the step of cutting and cutting the excess resin tank which has come out of the piezoelectric element is omitted. it can.

[0025]

Embodiment 3 FIGS. 16 to 18 are process diagrams showing this embodiment. The basic configuration is the same as that of the first embodiment. The same components are denoted by the same reference numerals and the description thereof will be omitted, and only the differences will be described. In this embodiment, as the resin material, a material in which a metal powder is dispersed in a liquid epoxy resin, which is a material of the back load material, is used. In addition, urethane-based resins can be used as the resin, and metal oxides and ceramics can be used as the powder.
Further, as the protective resin, both the acrylic UV-curable water-soluble resin and the silicone rubber described in Examples 1 and 2 can be used.

In this embodiment, of the entire surface of the piezoelectric element 13, the portion other than the surface 9 on which the back load material is formed is covered with the protective resin layer 3. Thereafter, a liquid resin, which is a material of the back load material, is applied to the piezoelectric element 13 and cured to form the resin layer 6. The portion of the cured resin that has come out of the piezoelectric element is removed by cutting or cutting. After or simultaneously with the removal of the resin layer 6, the protective resin is removed to form the back surface load member 7.

According to the present embodiment, by performing the above steps, it is possible to protect the surface other than the surface on which the back load material is formed when forming the back load material. Can be protected.

[0028]

Embodiment 4 FIGS. 19 to 21 are process diagrams showing this embodiment. The basic configuration is the same as that of the first embodiment. The same components are denoted by the same reference numerals and the description thereof will be omitted, and only the differences will be described. In this embodiment, a conductive resin, which is a material of the electrode terminal, was used as the resin material. As the protective resin, both the acrylic ultraviolet-curable water-soluble resin and the silicone rubber described in Examples 1 and 2 can be used.

In this embodiment, of the entire surface of the piezoelectric element 13 except for the surface 9 on which the electrode terminals are formed, the protective resin layer 3 is formed.
Cover with. Thereafter, a liquid conductive resin as a material of the electrode terminal is applied and cured to form the conductive resin layer 10. The electrode terminals 11 are formed by removing unnecessary portions of the cured conductive resin layer 10 by cutting or the like.

According to this embodiment, since the electrode terminals are formed, the wiring is easy. In addition, this formation can be performed in a state where the surface other than the formation surface of the electrode terminal is protected by performing the above-described steps, so that the surface other than the formation surface can be effectively protected.

[0031]

As described above, according to the method for manufacturing an ultrasonic transducer according to the present invention, the acoustic matching layer and the back load material using resin are formed easily and with high precision, and the electrical connection is made conductive. A high-performance ultrasonic transducer can be manufactured easily and reliably by using a resin.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a manufacturing process of the present invention.

FIG. 2 is a conceptual diagram showing a manufacturing process of the present invention.

FIG. 3 is a conceptual diagram showing a manufacturing process of the present invention.

FIG. 4 is a conceptual diagram showing a manufacturing process of the present invention.

FIG. 5 is a conceptual diagram showing a manufacturing process of the present invention.

FIG. 6 is a process chart showing Example 1.

FIG. 7 is a process chart showing Example 1.

FIG. 8 is a process chart showing Example 1.

FIG. 9 is a process chart showing Example 1.

FIG. 10 is a process chart showing Example 1.

FIG. 11 is a cross-sectional view illustrating a modification of the first embodiment.

FIG. 12 is a process chart showing Example 2.

FIG. 13 is a process chart showing Example 2.

FIG. 14 is a process chart showing Example 2.

FIG. 15 is a process chart showing Example 2.

FIG. 16 is a process chart showing Example 3.

FIG. 17 is a process chart showing Example 3.

FIG. 18 is a process chart showing Example 3.

FIG. 19 is a process chart showing Example 4.

FIG. 20 is a process chart showing Example 4.

FIG. 21 is a process chart showing Example 4.

FIG. 22 is a perspective view showing a conventional example.

FIG. 23 is a perspective view showing a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 outside portion 2 resin 3 protective resin 8 resin layer 13 piezoelectric element 14 surface electrode

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-48900 (JP, A) JP-A-60-191600 (JP, A) JP-A-58-206732 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) A61B 8/00-8/15

Claims (5)

(57) [Claims] 1. An ultrasonic transducer manufacturing method for manufacturing an ultrasonic transducer formed by bonding an acoustic matching layer, a piezoelectric element, and a back load material, wherein a surface of the piezoelectric element other than the acoustic matching layer is covered with a protective resin. A coating step, a coating / curing step of applying and curing a resin material to be an acoustic matching layer to the outside of a formation region thereof, and a removing step of removing an unnecessary portion and a protective resin from the cured resin. An ultrasonic transducer manufacturing method characterized by the above-mentioned. 2. An ultrasonic transducer manufacturing method for manufacturing an ultrasonic transducer in which an acoustic matching layer, a piezoelectric element, and a back load material are joined, wherein a surface of the piezoelectric element other than the surface on which the back load material is formed is covered with a protective resin. A coating step, a coating / curing step of applying and curing a resin material to be a back load material to an area outside the formation area thereof, and a removing step of removing an unnecessary portion and a protective resin from the cured resin material. An ultrasonic transducer manufacturing method characterized by the above-mentioned. 3. An acoustic matching layer, a piezoelectric element, and a back load member are formed by joining the acoustic matching layer, and an electrode terminal of a front surface electrode is drawn out of a portion other than a joint surface between the acoustic matching layer of the piezoelectric element and the back load material. In an ultrasonic transducer manufacturing method for manufacturing an ultrasonic transducer, a coating step of coating a portion other than a surface on which the electrode terminal is formed with a protective resin, and a coating and hardening process in which a conductive material of the electrode terminal is applied and hardened outside the formation region. A method for manufacturing an ultrasonic transducer, comprising: a step of removing an unnecessary portion and a protective resin from the cured conductive material. 4. The method of manufacturing an ultrasonic transducer according to claim 1, wherein said covering step is a step of covering all parts other than a surface on which an acoustic matching layer is formed. 5. The method of manufacturing an ultrasonic transducer according to claim 2, wherein said coating step is a step of coating all parts other than the surface on which the back load material is formed.