JPH02196600A - Method of forming split electrode in ultrasonic wave probe - Google Patents

Abstract

PURPOSE:To reduce a distance between electrode sections and to easily form a curved face split electrode by making one slot or over to an electrode forming film so as to form two electrode sections or over after the film is formed. CONSTITUTION:An electrode forming film 21 vulcanized initially is formed on a base 11, one slot (9a-9c) or over is made to form 2 electrode sections (22a-22c) and major vulcanization is applied. The electrode forming film 21 may be coated film or printed film or may be a sheet. Moreover, the film 21 is a film subjected to major vulcanization. Thus, the distance between electrode is decreased, the electrode shape accuracy is improved, the adjustment is facilitated, no choking takes place and the curved face split electrode is easily formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method of irradiating ultrasonic waves onto the surface or inside of an object such as a human body, and detecting an object using a received signal of a reflected wave that is reflected back. In an ultrasonic probe with a split electrode used as a transducer for observing the surface state or internal state of The present invention relates to a method for creating a divided electrode.

[Conventional technology]

As a conventional method for creating split electrodes, a method is known in which a dispersion or paste containing a predetermined silver is used, masked, and roll coating or screen coating is performed.

[L that the invention tries to solve! 81 In the above manufacturing method, it is difficult to maintain a distance between electrodes of 1 mm or less in masking, and in screen coating, since the rubber liquid is viscous, the screen is likely to become clogged. Furthermore, it is difficult to create curved electrodes such as concave electrodes suitable for focusing ultrasound beams by curving the piezoelectric layer, or convex electrodes suitable for emitting ultrasound beams omnidirectionally. Met.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and aims to provide a method for creating divided electrodes that can reduce the distance between electrode parts and easily create curved divided electrodes.

[Means to solve the problem]

As described in the above claims, the method for producing a split electrode of the present invention includes forming an initial vulcanized or main vulcanized electrode forming film, and then drilling one or more grooves in the wire film. The method is characterized in that two or more electrode portions are formed, and then, in the case of the above-mentioned film which has undergone initial vulcanization, main vulcanization is performed. This "electrode forming film" may be a coating film, a printed film, or a sheet. Further, this film may be an initially vulcanized film or a main vulcanized film, and in the former case, it is usually integrated later by main vulcanization or additional vulcanization, and in the latter case, it is usually integrated after main vulcanization or additional vulcanization. In some cases, the membranes will be glued and integrated.

Here, "initial vulcanization" broadly means semi-vulcanization, etc., which does not reach full vulcanization. Further, the grooves may be formed by cutting using a cutting edge attached to a grinder or the like, or by using a laser or ultrasonic waves.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 An explanatory diagram of the production method of this embodiment is shown in FIG.

(1) Manufacturing and preparing a semi-vulcanized base First, as shown in the same figure (Δ), a disc-shaped (outer diameter of about 20 mm)
A semi-vulcanized base 11 with a diameter of 0.5 mm and a thickness of 5 to 3 mm is prepared. This base 11 is manufactured, for example, by the following method.

A ceramic powder made of silicon nitride, alumina or lead zirconate titanate, etc., a synthetic rubber such as talolobrene rubber or silicone rubber, and a vulcanizing agent (for example, metal oxide, peroxide, sulfur, etc.) depending on the rubber used, and further is mixed with a vulcanization aid added as necessary, kneaded, and preformed. Next, during this preforming or the subsequent main molding, the semi-vulcanized base 11 is made into a semi-vulcanized state by shortening the processing time or by heating at a low temperature, etc., compared to the original vulcanization conditions.

(2)? After forming a film for forming an It polar bottom, 1 m of a dispersion or paste is formed on the surface by mixing silver powder, the above-mentioned rubber, a vulcanizing agent, and a solvent such as toluene.
This is coated or screen printed on the semi-vulcanized base 11 to form a first coating film. The blending ratio of silver powder to rubber is about 10 to 70% by volume. Thereafter, these were simultaneously subjected to initial vulcanization to form an electrode forming film 21 as shown in FIG. This film thickness is approximately 3 to 50
It is μm.

(3) Formation of divided electrodes After that, as shown in FIG. are brought into contact with each other to form a ring-shaped groove in this membrane 21. In this case, the thickness of the cutting edge 53 is approximately 0.1 to 0.5 mm,
A groove width corresponding to this is drilled, and as shown in FIGS. 3(C) and 3(D), three concentric grooves 9a-9c are finally formed, forming a small circular center electrode! l! B22a and three ring-shaped electrode parts 22 b-22 surrounding this in a concentric manner
A divided electrode 22 consisting of d was created. Note that this electrode 22
is the one before main vulcanization, and is not the same as the divided electrode 2 constituting the probe after main vulcanization, but for convenience, it is given the same name.

Pressure mentioned below? I! The same applies to layers, etc.

(4) Producing the probe Furthermore, if necessary, the probe as a final product is produced by inserting lead wires and main vulcanization.

To manufacture the probe shown in Fig. 6, it is necessary to insert a lead wire 5.6 for leading out to the outside, and if this lead wire is inserted before drilling the groove, Semi-vulcanized base 11
The four first lead wires 5a to 5d and the second lead wire 6 made of gold wire and having a thickness of 0.2 to 1 mm are passed through at predetermined positions. In this case, the first lead wire 5 is appropriately exposed and the second lead wire 6 is protruded to an appropriate height so as to make good contact with each electrode 2.4 after the final main vulcanization.

Thereafter, on this initial vulcanized electrode forming film 21, a piezoelectric material powder such as lead titanate, lead zirconate titanate, etc., the above-mentioned rubber, a vulcanizing agent, and a solvent are mixed to form an unvulcanized piezoelectric layer. (about 1
0 to 200 μm). The blending ratio of the piezoelectric material powder to the rubber is approximately 50 to 80% by volume. Next, a second coating film is formed at a predetermined position on this in the same manner as the first coating film, and further, an unvulcanized or semi-vulcanized rubber plate is placed on this second coating film. (protective layer) was disposed, and additional vulcanization was integrally performed on this laminate under a pressure of 50 Kg/Cm'' or more to produce a probe with the above configuration.

This includes the backing base l, the divided electrode 2 of the lower electrode, the piezoelectric layer 3, the common electrode 4 of the upper and side electrodes, the first lead wire 5, the second lead wire 6, and the protective layer (or 1/4λ matching layer). )7.

Each of the first lead wires 5 5a to 5d is electrically connected by contacting the lower surface of the center electrode portion 2a and the three ring-shaped electrode portions 2b to 2d, and is buried so as to penetrate through the base 1. has been done. The second lead wire 6 is electrically conductive by contacting the lower surface of the common electrode 4, and is further connected to the divided electrode 4.
An insulating layer 8 made of rubber, resin, etc. is formed on the side surface to prevent electrical contact with the base 1 and the divided electrode 2.
and is embedded so as to electrically insulate and penetrate the piezoelectric layer 3. As described above, both lead wires 5.6 are configured not to contact each other. The lower end of this lead wire 5.6 is exposed from the bottom surface of the base 1 and can be connected to an electric wire drawn out from the wave transmitting/receiving circuit side, or can serve as a terminal for mounting on a printed wiring board, and can be connected to the electrode 2.4. It has a structure that can be regulated to ensure good contact.

Furthermore, since the above-mentioned laminate is an integral body that is pressure-vulcanized and both lead wires 5.6 are vulcanized after being penetrated, the lead wires 5.6 are also firmly attached to the laminate. is integrally fixed to. As the protective layer 7, a polyester film or the like may be used instead of the film or plate, and in this case, it is formed by adhering to the surface of the laminate after vulcanization with an adhesive.

According to this manufacturing method, since the cutting edge of the grinder is small, the distance between the electrodes is small, and the accuracy of the electrode shape can be improved, and there is no clogging as in conventional screen coating.

Furthermore, according to this manufacturing method, as shown in FIGS. 3 and 4, the surface of the base 1.1 is made concave or convex, and an electrode forming film is formed thereon, and grooves are similarly formed. Then, the curved divided electrodes 23 and 24 can be easily formed. This is a structure that cannot be created by conventional screen coating or the like.

In particular, the former structure is very useful because it can converge the ultrasonic beam. A probe using this can be manufactured in the same manner as described above, as shown in FIG.

Furthermore, the division method (shape) can be various depending on the purpose and application. For example, a plurality of strip-shaped electrode parts (2e, etc.) as shown in FIG. It is also possible to form a plurality of electrode parts and the like arranged in the same direction.

Alternatively, a fully vulcanized base may be used, and an unvulcanized or fully vulcanized film may be adhered thereon by adhesion or the like, and grooves may be formed thereon.

This probe uses a gold wire as a lead, is placed through the inside of the laminate, and has a weight of 50K g/c.
Since a pressure of 1.5 m'' is applied, there is no damage to the lead, no cracking, and no disconnection between the electrode and the lead wire, and the oxidation resistance is also a concern.

Example 2 FIG. 2 shows a method for creating divided electrodes according to this example. That is,
First, as shown in FIG. 3A, an unvulcanized or semi-vulcanized piezoelectric layer 31 having initially vulcanized electrode films 21 and 41 formed on each surface is placed in the middle.

Thereafter, as shown in FIG. 5(B), this is attached to the lathe 51, and the cutting edge 53 of the grinder 52 is
By drilling a predetermined groove, a predetermined divided electrode 22 is formed, and the other electrode is used as a common electrode 41, as shown in FIG. Also, pressure 1! As PJ31, it is also possible to use one that has been fully vulcanized.

Furthermore, when manufacturing a predetermined probe, a predetermined lead such as a metal wire is arranged in a predetermined process as in the first embodiment. Further, the common electrode 41 is placed on the surface of the base l, a protective layer is further placed on the surface of the divided electrode 21, and the laminate is fully vulcanized as a whole to produce a probe. do. As shown in FIG. 7, this probe consists of (1) the divided electrode 2 as the upper electrode, the common electrode 4 as the lower electrode, and (2)
The four first lead wires 5a to 5d of the present embodiment have the same structure as the second lead wire 6 of the first embodiment, and the second lead wire 6 of the present embodiment has the same structure as the first lead wire 5 of the first embodiment. It is characterized by a structure.

When manufacturing this probe, the divided electrodes 22 on the piezoelectric layer 31 are placed on the surface of the base 11, that is, the piezoelectric layer 31 is placed upside down from the above, and when vulcanized, the divided electrodes 2 are placed on the surface of the base 11. A probe having the same structure as in Example 1 using a side electrode can be manufactured. As described above, according to the present manufacturing method, it is possible to easily manufacture a structure in which the divided electrode is the upper electrode and a structure in which the divided electrode is the lower electrode.

Furthermore, when a conductive base is used, the base itself can be used as a common electrode, so it is sufficient to form a divided electrode only on one surface of the piezoelectric layer, and the common electrode can be omitted. . In this case, the process can be simplified.

〔Effect of the invention〕

Since the method for creating a split electrode of the present invention forms a plurality of electrode parts by drilling one or more grooves, the distance between the electrodes can be reduced, which improves the accuracy of the electrode shape and improves its adjustment. can also be done easily.

Furthermore, there is no clogging as in conventional screen coating, and curved divided electrodes can be easily created. In particular, the probe with segmented electrodes produced by this method has excellent electrode precision and is of high quality.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a method for creating a divided electrode in Example 1, in which (A) is an explanatory diagram showing a state before creating a divided electrode, and (B) is an explanatory diagram showing a state in which a divided electrode is being created. (C) is an explanatory diagram showing the state after creating the divided electrode, (D) is a semi-planar explanatory diagram of the divided electrode, and FIG. 2 is an explanation showing the method for creating the divided electrode in Example 2. (8) is an explanatory diagram showing the state before creating the divided electrodes,
(B) is an explanatory diagram showing the state in which the divided electrodes are being created, (C) is an explanatory diagram showing the state after creating the divided electrodes, and the third
The figure is an explanatory cross-sectional view showing a concave split electrode, Fig. 4 is an explanatory cross-sectional view showing a convex split electrode, Fig. 5 is a plan view showing a strip-shaped split electrode, and Fig. 6 is a probe manufactured in Example ①. FIG. 7 is an explanatory sectional view of a probe with a split electrode as the lower electrode, and FIG. 8 is an explanatory sectional view of a probe with a concave split electrode. 1.11; backing base, 21; membrane for segmented electrodes, 2.
22.23.24; Split electrode, 2a-d21 a-e
; Electrode part, 3.31; Piezoelectric layer, 4.41; Earth electrode,
5: first conductive lead (lead wire), 6; second conductive lead (lead wire), 7; protective layer, 8; insulating layer, 9; groove, 51
; Lathe, 52; Grinder, 53; Cutting edge patent applicant: NGK Spark Plug Co., Ltd. Representative: Kiyomichi Kojima, patent attorney Figure 1 (C) Figure 2 Figure 5 Figure 7

Claims (1)

[Claims] (1) Ultrasound using a backing base made of ceramic powder and rubber or a piezoelectric layer made of piezoelectric powder and rubber with a split electrode made of conductive material powder and rubber and having one or more electrode parts on the surface of the piezoelectric layer made of piezoelectric material powder and rubber. In the above-mentioned method for creating a split electrode in a probe, an initially vulcanized or fully vulcanized electrode forming film is formed, and then one or more grooves are bored in the film to form two or more electrode parts. A method for producing a split electrode in an ultrasonic probe, characterized in that the film is then subjected to main vulcanization in the case of an initial vulcanization film.