JPH0448900A - Manufacture of ultrasonic probe - Google Patents

Abstract

PURPOSE:To ensure the continuity between a side electrode and a lead wire by adhering a diaphragm face, an acoustic matching layer, and the diaphragm face and a packing member respectively with a laminator adhesives and removing the resin before electric connection between the side electrode and the lead wire after curing. CONSTITUTION:A piezoelectric ceramic 1 having electrodes 2, 2 and side face electrodes 2a, 2a is inserted between removal films 9a, 9b, and irradiated with ultraviolet ray to cure a protection resin 10. After the removal films 9a, 9b are peeled and the lamination adhesives 5 is used in the normal process to laminate an acoustic matching layer 3 and a packing member with the piezoelectric ceramic 1 and heating and curing are applied while pressing the ceramic. The ceramic is immersed in tepid water of 30-40 deg.C or ultrasonic wave rinsed in water to solve and remove the cured protection resin 10. Thus, the acoustic matching layer 3 and the packing member 4 are adhered while the side electrode 2a of the piezoelectric ceramic 1 is not covered with the insulating lamination adhesives 5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of manufacturing an ultrasonic probe, and particularly to a method of manufacturing an ultrasonic probe that is made of piezoelectric ceramic and has electrodes on its side surface. .

[Prior Art] Medical ultrasound probes are widely used for dynamic observation of soft tissues in the body, such as the abdomen and chest, as images by emitting ultrasound waves from the skin surface into the body. Recently, in order to obtain more accurate diagnostic information, there has been an increasing demand for ultrasound probes to be swallowed through the mouth to clearly depict the appearance of the mucous membranes of the stomach wall. In particular, the demand for image diagnostic methods that use a medical endoscope to observe the affected area and the internal state using ultrasound will increase in the future as it provides more reliable information.

When an ultrasound probe is used in conjunction with a medical endoscope, the ultrasound probe is inserted into the endoscope's processing tool hole, so the ultrasonic probe is quite small. It is required to be small.

FIG. 3 shows an example of the structure of a conventionally used ultrasonic probe.

In FIG. 3, an electrode 2 is provided on the vibrating surface of the piezoelectric ceramic 1 for transmitting and receiving ultrasonic waves.

On the other hand, in order to secure a larger vibration surface and vibration area, the electrodes 2 on both the upper and lower vibration surfaces are placed on the side surface of the piezoelectric ceramic 1 that is different from the vibration surface that transmits and receives ultrasonic waves so as not to short-circuit. The electrodes extending from the electrodes 2.2 on both the upper and lower vibration surfaces are side electrodes 2a.

2a. This electrode 2 and side electrode 2
A is formed by vapor deposition or plating of a metal or conductive metal oxide on the piezoelectric ceramic l, or by coating with a conductive paint. An acoustic matching layer 3 is bonded and fixed to one vibrating surface of the piezoelectric ceramic 1 via a lamination adhesive 5 such as epoxy. Further, a backing material 4 is also bonded and fixed to the vibration surface of the piezoelectric ceramic 1 opposite to the vibration surface of the piezoelectric ceramic 1 to which the acoustic matching layer 3 is fixed via the lamination adhesive 5. Further, this piezoelectric ceramic l having an acoustic matching layer 3 and a backing material 4 is embedded in a mold housing 6 together with a lead wire 8, and a side electrode 2a of the piezoelectric ceramic 1 is connected to the lead wire 8 via a conductive adhesive 7. are electrically coupled.

When manufacturing such an ultrasonic probe by laminating layers, the acoustic matching layer 3 and the backing material 4 are first bonded to the piezoelectric ceramic l via the lamination adhesive 5, and then
After being hardened and embedded in a mold housing 6, the side electrode 2a of the piezoelectric ceramic 1 and the lead wire 8 are electrically coupled using a conductive adhesive 7, solder, or the like.

As for an ultrasonic probe using a piezoelectric ceramic having such a side electrode, the one described in Japanese Patent Application Laid-Open No. 63-242100 and the like has been proposed.

[Problems to be Solved by the Invention] By the way, when the acoustic matching layer 3 and the backing material 4 are respectively bonded to the piezoelectric ceramic l via the lamination adhesive 5 as described above, the amount of the lamination adhesive 5 is If the amount is too low, the piezoelectric ceramic 1 and the acoustic matching layer 3, or the piezoelectric ceramic 1 and the backing material 4 may peel off due to deterioration over time, so a large amount of the lamination adhesive 5 is generally applied.

However, if the amount of the lamination adhesive 5 is too large, the lamination adhesive 5 will protrude outside the bonding surface during bonding and cover the side electrodes 2a, as shown in FIG. After bonding the piezoelectric ceramic 1 having the side electrode 2a covered with the lamination adhesive 5, it is embedded in the mold housing 6, and the side electrode 2a of the piezoelectric ceramic 1 and the lead wire 8 are connected using the conductive adhesive 7. Even if an attempt is made to electrically connect the side electrodes 2a, the lamination adhesive 5 that already covers the side electrodes 2a does not have conductivity, resulting in poor conductivity.

In order to prevent such problems, Japanese Unexamined Patent Publication No. 63-2
Utilization of the invention described in 42100 can be considered. In this method, an auxiliary electrode that serves as a lead wire for the electrode is provided on a part of the electrode for overturning the backing. However, in order to obtain an ultrasonic probe as small as possible, a piezoelectric ceramic as small as possible (for example, 1 x 2 x 0.14 (mm)) should be used, and the vibration surface of this piezoelectric ceramic should be Although it is necessary to use the entire surface, when the auxiliary electrode is provided as described above, there is a problem that the auxiliary electrode generates reflected waves of unnecessary sound waves as noise, deteriorating the acoustic characteristics.

The present invention has been made in view of such conventional problems, and it is possible to easily create a minute ultrasonic probe without causing conductivity defects in the electrode part, and furthermore, as a product, it is possible to It is an object of the present invention to provide a manufacturing method that does not deteriorate the acoustic characteristics of a probe.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an acoustic matching layer and one of the vibrating surfaces of a piezoelectric ceramic having an electrode on a side surface different from the two vibrating surfaces that transmit and receive ultrasonic waves. , and the other of the vibrating surfaces and the backing material are bonded to each other using the lamination adhesive to form a laminate, and a part of the laminate is embedded in a mold housing, and then
In the method for manufacturing an ultrasonic probe in which the side electrode and the lead wire buried in the mold housing are electrically coupled, the side electrode is covered with a resin, and the vibrating surface and the The acoustic matching layer, the vibration surface, and the backing material are each bonded using the lamination adhesive, and after the lamination adhesive is cured and before the side electrode and the lead wire are electrically connected, the I'm trying to remove the resin.

[Operation] According to the above means, the side electrodes are covered with resin in advance before the acoustic matching layer or backing material is laminated and aligned on the vibrating surface of the piezoelectric ceramic using a lamination adhesive. Even if the side surfaces are covered with the lamination adhesive, the side electrodes are protected by the resin, and the side electrodes are exposed as long as the resin is removed. Therefore, conduction between the side electrode and the lead wire can be ensured.

In addition, the electrical connection between the side electrode and the lead wire was
Unlike the invention described in Japanese Patent No. 3-242100, this method is performed without using an auxiliary electrode, so that the acoustic characteristics of the ultrasonic probe as a product are not deteriorated.

[Example 1 (First Example) A first example of the present invention will be described based on FIGS. 1 and 2.

First, a piezoelectric ceramic 1 having electrodes 2, 2 and side electrodes 2a, 2a is sandwiched between release films 9a, 9b.

The release film used at this time is transparent and has good ultraviolet transmittance, such as olefin-based, polyester-based, or fluorine-based films. Next, a dispenser, a syringe, or the like is used to inject the side electrode 2a into the area defined by the release films 9a, 9b and the side electrodes 2a, 2a.
.

The protective resin 10 is evenly injected so that the resin 2a is wetted.

Examples of the protective resin 1o at this time include modified polyacrylamide, modified polyacrylic acid, modified polymethacrylic acid, modified polyitaconic acid, modified polyvinyl alcohol,
Modified polyethylene oxide, modified polyvinyl pyrrolidone, modified polyvinyl methyl ether, etc. have 100 NH in the molecule.

A photopolymerizable water-soluble product made by adding a photopolymerization initiator such as acetophenone or benzophenone and additives such as an adhesion promoter or thickener to a linear polymeric polymer or oligomer having -COOH, -○H groups, etc. A polymer resin is used.

Next, the protective resin 1o is cured by irradiating high-intensity ultraviolet rays through the release films 9a and 9b or by irradiating ultraviolet rays from the side. The state up to this point is shown in FIG.

Next, after peeling off and removing the release films 9a and 9b, the acoustic matching layer 3 and backing material 4 are laminated and bonded to the piezoelectric ceramic 1 using a lamination adhesive 5 in a normal process, and heated and cured while applying pressure. let In this case, if a normal two-component poxy adhesive is used as the lamination adhesive 5, curing will be completed in about 2 hours at 80°C. After the adhesive is cured, the result is as shown in FIG. 2, and the cured protective resin 10 is dissolved and removed by immersing it in lukewarm water at 30 to 40 DEG C. or by performing ultrasonic cleaning in water. Further, the lamination adhesive 5 that has hardened while protruding is easily removed with a knife or the like.

Note that if moisture penetration into the backing material is a problem due to the performance of the ultrasonic probe, use an organic solvent such as acetone or ethanol instead of hot water or water when dissolving the protective resin 10. use In this case as well, it is advisable to perform ultrasonic cleaning. If an epoxy adhesive is used as the lamination adhesive 5, it can sufficiently withstand solvents and ultrasonic cleaning.

According to the above embodiment, the following effects can be obtained.

That is, before the acoustic matching layer 3 and the backing material 4 are laminated and aligned on the vibrating surface of the piezoelectric ceramic 1 using the lamination adhesive 5, the side electrodes are covered with the protective resin 10 in advance. The acoustic matching layer 3 and the backing material 4 can be bonded without the side electrode 2a of the piezoelectric ceramic 1 being covered with the insulating lamination adhesive 5, and as a result, the side surface of the piezoelectric ceramic 1 can be The electrode 2a and the lead wire 8 can be reliably electrically coupled using the conductive adhesive 7, solder, or the like.

Furthermore, since electrical coupling between the side electrode 2a and the lead wire 8 is performed without using an auxiliary electrode, unlike the invention described in JP-A-63-242100, the acoustic characteristics of the ultrasonic probe as a product can be improved. It will not deteriorate.

(Second Example) A second example of the present invention will be described below, but the difference from the first example is that cyanoacrylate was used instead of the photopolymerizable water-soluble polymer resin used as the protective resin 10. The point is that a resin based on this method is used. The manufacturing process is the same as the first example,
First, the protective resin 10 is injected into the area defined by the release films 9a, 9b and the side electrodes 2a, 2a. Protective resin 1
The cyanoacrylate resin used as No. 0 is commonly used as an instant adhesive and has the property of reacting with moisture in the air and curing in a short time. However, when a large amount is injected as in the present invention, the curing speed becomes extremely slow, so after injecting the protective resin 10, an aromatic amine dissolved in ethanol is added as a curing accelerator.

Next, after the protective resin 10 is cured, the hard-to-form film 9a is formed.

After peeling off and removing 9b, apply the laminating adhesive 5 in the normal process.
The acoustic matching layer 3 and the backing material 4 are laminated and bonded to the piezoelectric ceramic 1 using a method, and heated and cured while applying pressure. After curing, the cured protective resin 10 can be dissolved and removed by immersing it in an organic solvent such as acetone, nitromethane, dimethylformamide, etc. and subjecting it to ultrasonic cleaning for several minutes. The lamination adhesive 5 that has hardened while protruding can be easily removed with a knife or the like.

According to the above embodiment, the following effects can be obtained.

That is, the acoustic matching layer 3 and the backing material 4 can be bonded without the side electrode 2a of the piezoelectric ceramic l being covered with the insulating lamination adhesive 5, and as a result, after being embedded in the mold housing 6, the piezoelectric The side electrode 2a of the ceramic 1 and the lead wire 8 can be reliably electrically coupled using the conductive adhesive 7, solder, or the like.

Further, since electrical coupling between the side electrode 2a and the lead wire 8 is performed without using an auxiliary electrode unlike the invention described in JP-A-63-242100, the acoustic characteristics of the ultrasonic probe as a product are It does not cause deterioration.

[Effects of the Invention] In the method for manufacturing an ultrasound probe of the present invention, one of the vibrating surfaces of a piezoelectric ceramic having an electrode on a side surface different from the two vibrating surfaces that transmit and receive ultrasonic waves, and an acoustic matching layer; After forming a laminate by bonding the other of the vibrating surfaces and each of the backing materials using the lamination adhesive, and embedding a part of the laminate in a mold housing,
When electrically coupling the side electrode and the lead wire embedded in the mold housing, the vibration surface and the acoustic matching layer, and the vibration surface and the backing are connected with the side electrode covered with resin. Each of the materials is adhered using the lamination adhesive, and after the lamination adhesive has hardened and before the electrical connection between the side electrode and the lead wire,
Since the resin is removed, even if the side surfaces are covered with the lamination adhesive, the side electrodes are protected by the resin, and the side electrodes can be exposed by removing the resin. Therefore, conduction between the side electrode and the lead wire can be ensured, and quality can be improved.

In addition, the electrical connection between the side electrode and the lead wire was
Unlike the invention described in Japanese Patent Publication No. 3-242100, this method is carried out without using an auxiliary electrode, so that the acoustic characteristics of the ultrasonic probe as a product are not deteriorated.

[Brief explanation of drawings]

1 and 2 are process cross-sectional views in an embodiment of the method for manufacturing an ultrasound probe according to the present invention, FIG. 3 is a cross-sectional view of a normal ultrasound probe, and FIG. 4 is a conventional defect. FIG. 3 is a cross-sectional view of an ultrasonic probe in the process of being manufactured, in which this occurs. ... Piezoelectric ceramic a ... Side electrode ... Acoustic matching layer ... Backing material ... Lamination adhesive ... Protective resin (resin) Patent applicant Olympus Optical Industry Co., Ltd. Takeshi Nara, Company Agent Patent Attorney 6. Amend Figures 3 and 4 as shown in the attachment. September 28, 1990 7, List of attached documents

Claims (1)

[Claims] Using the laminating adhesive, one of the vibrating surfaces of a piezoelectric ceramic having an electrode on a side different from the two vibrating surfaces that transmit and receive ultrasonic waves, an acoustic matching layer, and the other vibrating surface and a backing material, respectively. A laminate is formed by adhering the laminate, a part of the laminate is embedded in a mold housing, and then the side electrode and the lead wire embedded in the mold housing are electrically coupled. In the method for manufacturing an ultrasonic probe, the vibration surface and the acoustic matching layer, with the side electrode covered with resin,
and bonding each of the vibration surface and the backing material using the lamination adhesive, and removing the resin after the lamination adhesive has hardened and before the side electrode and the lead wire are electrically connected. A method for manufacturing an ultrasonic probe, characterized in that: