JPH05253224A - Manufacture of ultrasonic wave transducer - Google Patents

Abstract

PURPOSE:To manufacture a high performance ultrasonic transducer by forming an acoustic matching layer and back face load material easily and accurately, and generating electric connection easily and certainly by the use of a conductive resin. CONSTITUTION:Among the whole surface of a piezoelectric element 13, the other surface portion of either of the acoustic matching layer, back face load material, and electrode terminal than where a resin layer is formed, is covered with a protection resin 3. This is followed by application of a resin (unhardened, liquid state) 2 as object, which is left hardening. That portion 1 of the hardened resin which has extruded to outside the piezoelectric element, is removed by cutting, machining, etc. After or at the same time as the removing process of the resin layer is finished, the protection resin 3 is removed by melting or exfoliation, and the resin layer as object is formed on the acoustic matching layer, back face load material, and electrode terminal.

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 medical ultrasonic endoscopes,
Specifically, the present invention relates to a method of manufacturing an acoustic matching layer / back load material and a method of electrically connecting a transducer.

[0002]

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

The above-mentioned ultrasonic transducer is generally constructed by using piezoelectric ceramics, and an electrode formed on the surface thereof is used to apply a high frequency voltage pulse to the piezoelectric ceramics to rapidly deform the piezoelectric ceramics. , Oscillate an ultrasonic pulse. Since this piezoelectric ceramic has a large difference from the acoustic impedance of the living body,
Ultrasonic waves are reflected at the interface between the two, resulting in 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 radiation surface side of the piezoelectric ceramic.

22 and 23 show the structure of a general ultrasonic transducer. 22 shows the case where the acoustic matching layer 51 is one layer, and FIG. 23 shows the case where the acoustic matching layer 51 is multi-layered. The acoustic matching layer 51 is generally made of a resin plate or a plate-shaped product obtained by mixing a resin with powder such as ceramics, and is formed by adhering the plate to the piezoelectric ceramics 52. For example, JP-A-60-112399
In the invention described in the publication, the piezoelectric ceramics 5 is formed after the plate-shaped acoustic matching layer 51 is formed, as in the above method.
It is glued to 2.

A back load material 53 is provided on the opposite side of the acoustic radiation surface of the piezoelectric ceramics 52 to prevent oscillated ultrasonic waves from leaking from the back surface of the ultrasonic transducer and from the back surface of the ultrasonic transducer. This prevents the noise from mixing in. This back load material 53 is generally made of a resin plate or a plate-shaped product obtained by mixing resin with powder of ceramics, metal or the like, and is bonded to the piezoelectric ceramics 52 in the same manner as the acoustic matching layer 51. I am creating it.

[0006]

However, in the above-mentioned prior art, when the step of joining the piezoelectric element to the acoustic matching layer and the back load material is performed, the adhesive is a surface other than the joining surface, for example, a surface for making an electrical connection. There is a problem of adhesion on the electrodes. In order to prevent the adhesion, generally, the amount of the adhesive is controlled or the adhered adhesive is wiped before being cured.

When the amount of the adhesive is controlled, it is important to control the adhesive in a small amount. That is, if the amount of the adhesive is too small, the adhesive will adhere to unnecessary portions. Further, if the amount is very small, the adhesive strength will be lowered.

Further, since the oscillation frequency of an ultrasonic transducer for an ultrasonic endoscope is on the order of several MHz to several tens of MHz, it is one of the wavelengths of ultrasonic waves that are generally used.
The acoustic matching layer having a thickness of about / 4 is a thin plate having a thickness of several tens of μm class because the sound velocity of 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 drawback in that the position of the bonded component is displaced during the work.

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

[0010]

According to the present invention, in an ultrasonic transducer in which an acoustic matching layer, a piezoelectric element and a back load material are joined, a protective resin is provided on the piezoelectric element except for the surface on which the acoustic matching layer is formed. After coating, a resin material for the acoustic matching layer is applied and cured, and a portion of the cured resin outside the piezoelectric element and the protective resin are removed to form the acoustic matching layer.

Further, in an ultrasonic transducer in which an acoustic matching layer, a piezoelectric element and a backside load material are joined together, a resin material for the backside load material is formed after coating the surface of the piezoelectric element other than the backside load material forming surface with a protective resin. Is applied and cured, and a portion of the cured resin outside the piezoelectric element and the protective resin are removed to form a back load material.

Furthermore, an ultrasonic transducer in which an acoustic matching layer, a piezoelectric element, and a back load material are matched,
In an ultrasonic transducer having an electrode terminal of a surface electrode drawn out other than the bonding surface between the acoustic matching layer of the piezoelectric element and the back load material, after coating the surface other than the surface where the electrode terminal is formed with a protective resin, In this method, an electrode terminal is formed by applying and curing a conductive material and removing an unnecessary portion of the cured conductive material and the protective resin.

The protective resin is preferably a resin soluble in water or an organic solvent, or silicone rubber.

1 to 5 are conceptual views 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 of the acoustic matching layer, the back load material, and the electrode terminal on which the resin layer is formed is covered with the protective resin 3. After that, the target resin (uncured and liquid) 2 is applied and cured. Cut the part 1 of the hardened resin that is outside the piezoelectric element.
Remove by cutting, etc. After the resin layer removal processing is completed, or at the same time, the protective resin 3 is removed by melting or peeling to form the desired resin layer 8 such as the acoustic matching layer, the back load material, and the electrode terminals.

Through the above steps, it is possible to effectively protect any part of the acoustic matching layer, the back load material and the electrode terminal other than the surface on which the resin layer is formed. Therefore, it is possible to prevent the adhesive from adhering to unnecessary portions and the decrease in adhesive strength.

[0016]

Embodiment 1 FIGS. 6 to 11 show the present 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 to this, an acrylic UV-curable water-soluble resin that is a protective resin, an ultraviolet irradiation device for curing the protective resin, a liquid epoxy resin that is a material for the acoustic matching layer, and an epoxy resin coating device (all shown No) is used.

The acoustic matching layer forming step will be described below. After covering a part 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 UV-curable water-soluble resin, UV rays are irradiated from a UV irradiation device (not shown). By hardening, the piezoelectric element 13
A water-soluble resin is coated as the protective resin layer 3.

After that, a liquid resin which is 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 the coating method. With respect to the flat piezoelectric element plate, when a resin of several thousands cps class is used by dipping, a smooth resin layer having a thickness of several tens μm can be easily formed. The thickness of the resin layer can be controlled strictly and easily by controlling the pulling speed of the piezoelectric element plate. The portion of the hardened resin that extends outside the piezoelectric element is removed by cutting or cutting. After or simultaneously with the removal process of the resin layer, the protective resin is dissolved and removed by water cleaning or alcohol cleaning to form the acoustic matching layer 5.

In the present embodiment, by taking the above steps, the acoustic matching layer is formed while effectively protecting the surface other than the surface on which the acoustic matching layer is formed.

According to the present embodiment, since the piezoelectric element and the surface electrode are exposed in the portion protected by the protective resin after the protective resin is removed, post-processing such as bonding and wiring can be directly performed.

By using the same process as in this embodiment, changing the liquid resin which is the material of the acoustic matching layer, performing the dipping process a plurality of times and then removing the surplus resin and the protective resin, 11. A multi-layered acoustic matching layer 5 as shown in FIG.
Can also be formed. Other methods of applying the resin layer to be the acoustic matching layer include spraying and printing. Similarly, as the liquid resin which is the material of the acoustic matching layer, urethane series can also be used. Further, although the resin layer is formed by the coating method in the present embodiment, it is obvious that the method can also be applied to the method of joining the resin layer having 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, and the same components are designated 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. Of the entire surface of the piezoelectric element 13, a portion other than the surface 9 on which the acoustic matching layer is formed is covered with liquid silicone rubber, and then left at room temperature or heated in a high temperature tank to cure the silicone rubber. 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 tank is formed only on the forming surface 9. Silicone rubber is removed by dissolving the silicone rubber by ultrasonic cleaning in a silicone dissolving agent, or by mechanically peeling using a silicone rubber having a high releasability.

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 / cutting the surplus resin tank that is outside the piezoelectric element is omitted. it can.

[0025]

Third Embodiment FIGS. 16 to 18 are process drawings showing this embodiment. The basic configuration is the same as that of the first embodiment, and the same components are designated 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 liquid epoxy resin in which metal powder is dispersed is used as a material for the back load material. Other than this, urethane series can be used as the resin, and metal oxides and ceramics can be used as the powder.
As the protective resin, both the acrylic UV-curable water-soluble resin described in Examples 1 and 2 and the silicone rubber can be used.

In this embodiment, of the entire surface of the piezoelectric element 13, the portion other than the surface 9 forming the back load material is covered with the protective resin layer 3. After that, 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 hardened resin that extends outside the piezoelectric element is removed by cutting or cutting. After the removal processing of the resin layer 6 is completed or at the same time, the protective resin is removed to form the back load material 7.

According to the present embodiment, by taking the above steps, it is possible to protect the surface other than the surface on which the back load material is formed when the back load material is formed, so that the surface other than the formation surface is effective. Can be protected.

[0028]

Fourth Embodiment FIGS. 19 to 21 are process diagrams showing this embodiment. The basic configuration is the same as that of the first embodiment, and the same components are designated 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 for the electrode terminals, is used as the resin material. As the protective resin, both the acrylic UV-curable water-soluble resin described in Examples 1 and 2 and the silicone rubber can be used.

In this embodiment, of the entire surface of the piezoelectric element 13, the portion other than the surface 9 forming the electrode terminals is covered with the protective resin layer 3
Cover with. After that, a liquid conductive resin which is a material for the electrode terminals is applied and cured to form the conductive resin layer 10. 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 by taking the above steps while protecting the surface other than the surface on which the electrode terminals are formed, so that the surface other than the surface on which the electrode terminals are formed can be effectively protected.

[0031]

As described above, according to the ultrasonic transducer manufacturing method of the present invention, the acoustic matching layer / back load material using resin can be easily and highly accurately formed, and the electrical connection can be made conductive. A high performance ultrasonic transducer can be manufactured by using a resin easily and reliably.

[Brief description of 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 diagram showing Example 1.

FIG. 7 is a process diagram showing Example 1.

FIG. 8 is a process drawing showing the first embodiment.

FIG. 9 is a process drawing showing Example 1.

FIG. 10 is a process chart showing Example 1.

FIG. 11 is a cross-sectional view showing a modified example of the first embodiment.

FIG. 12 is a process diagram showing a second embodiment.

FIG. 13 is a process diagram showing a second embodiment.

FIG. 14 is a process diagram showing a second embodiment.

FIG. 15 is a process drawing showing Example 2;

FIG. 16 is a process drawing showing Example 3;

FIG. 17 is a process diagram showing a third embodiment.

FIG. 18 is a process drawing showing Example 3;

FIG. 19 is a process drawing showing Example 4;

FIG. 20 is a process drawing showing Example 4;

FIG. 21 is a process drawing 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]

 1 Outer portion 2 Resin 3 Protective resin 8 Resin layer 13 Piezoelectric element 14 Surface electrode

Claims (5)

[Claims] 1. An ultrasonic transducer comprising an acoustic matching layer, a piezoelectric element, and a backside load member joined together, after covering the surface of the piezoelectric element other than the acoustic matching layer forming surface with a protective resin,
A method for manufacturing an ultrasonic transducer, characterized in that the acoustic matching layer is formed by applying and curing a resin material for the acoustic matching layer, and removing a portion of the cured resin outside the piezoelectric element and the protective resin. .. 2. An ultrasonic transducer comprising an acoustic matching layer, a piezoelectric element, and a backside load material joined together, after coating the surface of the piezoelectric element other than the backside load material forming surface with a protective resin,
A method of manufacturing an ultrasonic transducer, characterized in that a back load material is formed by applying and curing a resin material of a back load material and removing a portion of the hardened resin outside the piezoelectric element and the protective resin. .. 3. An ultrasonic transducer in which an acoustic matching layer, a piezoelectric element and a backside load material are matched with each other, and a surface electrode which is drawn out other than a joint surface between the acoustic matching layer of the piezoelectric element and the backside load material. In the ultrasonic transducer having the electrode terminal, the surface other than the surface on which the electrode terminal is formed is covered with a protective resin, and then the conductive material of the electrode terminal is applied and cured, and the unnecessary portion of the cured conductive material and the protective resin. An ultrasonic transducer manufacturing method, characterized in that the electrode terminals are formed by removing the. 4. The ultrasonic transducer manufacturing method according to claim 1, wherein the protective resin is a resin that is soluble in water or an organic solvent. 5. The ultrasonic transducer manufacturing method according to claim 1, wherein the protective resin is silicone rubber.