JP3722950B2 - Ultrasonic vibrator and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic vibrator and a manufacturing method thereof, and more particularly to a structure of a laminated ultrasonic vibrator.
[0002]
[Prior art]
In order to make the ultrasonic vibrator have a low impedance, a piezoelectric material is laminated. Such a stacked-type ultrasonic transducer is formed by laminating a plurality of piezoelectric bodies 10 and 12 as schematically shown in FIG. The lower electrode 18 is formed, and an intermediate electrode 26 is formed between the piezoelectric bodies 10 and 12. A positive electrode and a negative electrode are formed by alternately connecting a plurality of electrodes from the upper electrode 14 to the lower electrode 18 every other electrode. Specifically, the upper surface electrode 14 and the lower surface electrode 18 are interconnected by a wraparound electrode 22, and a signal line 24 is further connected to them. A signal line 20 as a lead is connected to the intermediate electrode 16 by soldering 26 or the like. When a voltage is applied between the signal lines 20 and 26, an ultrasonic wave is generated.
[0003]
[Problems to be solved by the invention]
By the way, it has been pointed out that it is difficult to manufacture such a laminated ultrasonic transducer. In particular, as shown in FIG. 7, the lead connection to the end portion of the intermediate electrode 16 requires skill. In this case, it is possible to connect the signal lines using the side surfaces of the laminated body, but it is difficult to connect when the piezoelectric body is thin.
[0004]
The above problem occurs particularly when the laminated body is configured by an even number of piezoelectric elements. In other words, the number of surface electrodes becomes an odd number, and the polarities of the upper surface electrode and the lower surface electrode become the same. As a result, the signal lines must be connected to the side surfaces of the stacked body for the different polarities.
[0005]
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to facilitate manufacture of a laminated ultrasonic transducer, and in particular to facilitate connection of leads.
[0006]
Another object of the present invention is to facilitate the connection of leads by making the polarity of the upper surface electrode and the lower surface electrode of the multilayer body different in the multilayer ultrasonic transducer including an even number of piezoelectric bodies. is there.
[0007]
[Means for Solving the Problems]
(1) In order to achieve the above object, the present invention comprises a plurality of stacked piezoelectric bodies, a dummy body additionally stacked on the plurality of piezoelectric bodies, the plurality of piezoelectric bodies, and the dummy body. A plurality of surface electrodes formed between the upper and lower surfaces of the multilayer body and the members, and one and the other wraparound electrodes that alternately connect the plurality of surface electrodes to each other using one side surface and the other side surface of the multilayer body; , Including.
[0008]
According to the above configuration, a laminated body can be formed by taking a dummy body in the upper stage or the lower stage, and as a result, the number of members constituting the laminated body can be adjusted to freely set the polarity relationship between the upper surface electrode and the lower surface electrode. it can. Therefore, it is easy to make the polarities of the upper surface electrode and the lower surface electrode different from each other, and therefore the problem at the time of lead connection can be solved.
[0009]
In a preferred aspect of the present invention, the multilayer body includes an even number of piezoelectric bodies and one dummy body, and the upper surface electrode and the lower surface electrode of the multilayer body have different polarities. For example, the dummy body is provided at the uppermost stage and functions as an acoustic matching layer, or the dummy body is provided at the lowermost stage and functions as a backing layer or a backing side acoustic matching layer. Here, the backing-side acoustic matching layer is a member that matches the acoustic impedance between the piezoelectric body and the backing layer.
[0010]
(2) In order to achieve the above object, the present invention includes a first electrode forming step of forming a surface electrode between each member of a plurality of piezoelectric bodies and a dummy body, and a plurality of steps after the surface electrode is formed. A step of forming a laminate by laminating the piezoelectric body and the dummy body, a second electrode step of forming an electrode so as to surround the laminate, and a plurality of surfaces from the upper surface electrode to the lower surface electrode of the laminate And a post-processing step of performing an insulating process for alternately distributing the electrodes to the positive electrode and the negative electrode.
[0011]
According to the above configuration, when a piezoelectric body having a surface electrode as an intermediate electrode is laminated including a dummy body to form a laminated body, an electrode is then formed around the laminated body. Thereafter, a laminated ultrasonic transducer is manufactured through necessary insulation treatment. In forming each electrode, a sputtering method, a vapor deposition method, or the like can be employed. In the lamination process, for example, an adhesive is used for joining the members.
[0012]
In a preferred aspect of the present invention, the insulating treatment step includes a pretreatment step of insulating one end portion of the surface electrode between the members before the lamination step, and the lamination step after the second electrode formation step. And a post-processing step of insulating one end of the upper surface electrode and the lower surface electrode of the body.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
[0014]
FIG. 1 shows a method for manufacturing an ultrasonic probe according to the present invention. The manufacturing method of this embodiment is demonstrated based on FIG. 1, referring FIGS.
[0015]
In S101 shown in FIG. 1, electrodes are formed on both surfaces of each piezoelectric body as shown in FIG. That is, electrodes 30 and 32 as surface electrodes are formed on the piezoelectric body 10, and electrodes 34 and 36 as surface electrodes are formed on the piezoelectric body 12. Here, one end portions (left end portions) of the electrodes 32 and 34 located between the piezoelectric bodies 10 and 12 are cut to form insulating portions 32A and 34A. Further, one end portion (right end portion) of the lower electrode 36 of the piezoelectric body 12 is also cut to form an insulating portion 36A. By forming these insulating portions, as described later, each surface electrode can be alternately distributed to the positive electrode and the negative electrode. Accordingly, the insulating portions are alternately formed in the order of lamination. In forming each surface electrode, for example, a known sputtering method can be applied. In forming the insulating portion, it can be removed by etching or the like. In FIG. 2, reference numerals 100 and 102 denote laminated elements.
[0016]
In S102 shown in FIG. 1, each member is bonded to each other including the backing layer 40 as a dummy body in addition to the laminated elements 100 and 102 as shown in FIG. In this case, for example, an adhesive is used. The code | symbol 104 in FIG. 3 has shown the laminated body. In this embodiment, the backing layer 40 has the same thickness as the piezoelectric bodies 10 and 12, but is not necessarily limited to such thickness. The backing layer 40 functions as a dummy body, that is, has a function of adding one surface electrode. Therefore, the thickness can be adjusted as necessary. In the example shown in FIG. 3, the dummy body is provided on the lower side, but it is needless to say that a dummy body can be provided on the upper stage of the laminated body, which will be described later with reference to FIG. 6. As is well known, the backing layer 40 has a role of absorbing ultrasonic waves emitted backward.
[0017]
In S <b> 103 shown in FIG. 1, electrodes are formed around the laminate 104. Also in this case, a sputtering method or the like is used. FIG. 4 shows the peripheral electrode 42 formed as described above. The peripheral electrode 42 includes one sneak electrode 42a, the other sneak electrode 42b, and a surface electrode 42c. Note that since the electrode corresponding to the upper surface of the multilayer body 104 has already been formed, it is not necessary to form the upper surface electrode of the multilayer body 104 at this point in this embodiment. Of course, when the surface electrode corresponding to the upper surface electrode is not formed in the step of S101, such upper surface electrode is formed in S103. Further, when the surface electrode is formed on the lower side of the backing layer 40 in step S101, it is not necessary to form the surface electrode on the lower side of the backing layer 40 in S103.
[0018]
In any case, the electrodes are formed so as to surround the upper surface, the lower surface, and the side peripheral surface of the laminate 104. The stacked body 104 has four side surfaces, and the wrap-around electrodes 42a and 42b are formed by using two of the side surfaces facing each other.
[0019]
Thus, when an electrode is formed around the laminated body 104, the electrodes 32 and 34 existing between the piezoelectric bodies 10 and 12, that is, the intermediate electrode are connected to the wraparound electrode 42b at this end. Since the other end of the intermediate electrode is insulated as described above, connection to the wraparound electrode 42a at the other end is prevented. Similarly, one end of the surface electrode, that is, the intermediate electrode located between the piezoelectric body 12 and the backing layer 40 is connected to the wraparound electrode 42a, and the other end is insulated from the wraparound electrode 42b by the above-described insulation treatment. Is done.
[0020]
In the step of S104, as shown in FIG. 4, the electrodes are cut at two corners of the laminate 104. This is indicated by reference numerals 44A and 44B, and by such processing, each surface electrode can be alternately distributed to the positive electrode and the negative electrode.
[0021]
In S105 shown in FIG. 1, as shown in FIG. 5, a signal FPC (flexible printed circuit board) 58 is connected to the electrode corresponding to the positive electrode, and the ground lead 56 is connected to the electrode corresponding to the negative electrode or the ground. In S106 of FIG. 1, a polarization process is performed on the piezoelectric body, and in S107, an ultrasonic transducer is assembled as shown in FIG. Matching layers 50 and 52 are provided on the upper side of the laminated body 104, and a backing layer 54 is provided on the lower side of the laminated body 104. Both the backing layer 40 and the backing layer 54 cooperate to absorb ultrasonic waves backward.
[0022]
As shown in FIG. 5, the surface electrodes are alternately distributed to two polarities, and the signal lines can be easily connected to the respective polarities. Such connection of the signal lines has an advantage that the operation can be greatly simplified even when the connection is performed by soldering or the like.
[0023]
As described above, according to the above embodiment, the number of elements constituting the multilayer body 104 can be made odd by adding a dummy body. As a result, the polarity of the upper surface electrode and the lower surface electrode of the multilayer body can be made different. Signal lines can be connected more easily than in the past. In the above embodiment, the case where there are two piezoelectric bodies has been described, but the present invention can be applied to the case where three or more piezoelectric bodies are used.
[0024]
FIG. 6 shows an embodiment in which a matching layer 60 as a dummy body is provided on the upper layer of the stacked body 104. A matching layer 62 is provided above the matching layer 60, and a backing layer 64 is provided below the stacked body 104. Even in such an embodiment, the signal lines can be easily connected by changing the polarities of the upper surface electrode and the lower surface electrode of the laminate 104 as a result.
[0025]
【The invention's effect】
As described above, according to the present invention, it is possible to facilitate the manufacture of a laminated ultrasonic probe, and particularly to easily connect leads. Further, according to the present invention, in the laminated ultrasonic probe including an even number of piezoelectric bodies, the polarity of the upper surface electrode and the lower surface electrode of the laminated body can be made different, and as a result, the signal to those electrodes can be changed. The advantage is that the connection to the line can be made easily.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a method for manufacturing an ultrasonic transducer according to the present invention.
FIG. 2 is a diagram showing the formation of electrodes for two piezoelectric bodies.
FIG. 3 is a diagram showing formation of a laminated body.
FIG. 4 is a diagram showing a state in which electrodes are formed around a laminated body.
FIG. 5 is a diagram showing a schematic diagram of an ultrasonic transducer according to the present invention.
FIG. 6 is a schematic diagram showing another embodiment.
FIG. 7 is a schematic diagram of a conventional ultrasonic transducer.
[Explanation of symbols]
10, 12 Piezoelectric body, 30, 32, 34, 36 electrode (surface electrode), 32A, 34A, 36A insulating part, 40 backing layer (dummy body), 42 peripheral electrode, 42a, 42b wraparound electrode, 104 laminate.

Claims (6)

A plurality of laminated piezoelectric bodies;
A dummy body additionally laminated to the plurality of piezoelectric bodies;
A plurality of surface electrodes formed between the upper and lower surfaces of the laminate composed of the plurality of piezoelectric bodies and the dummy body and members;
Using one side and the other side of the laminate, one and the other sneak electrodes alternately connecting a plurality of surface electrodes;
An ultrasonic transducer comprising: The ultrasonic transducer according to claim 1,
The laminate is composed of an even number of piezoelectric bodies and one dummy body,
The ultrasonic transducer according to claim 1, wherein the upper surface electrode and the lower surface electrode of the laminate have different polarities. The ultrasonic transducer according to claim 1,
The ultrasonic transducer according to claim 1, wherein the dummy body is provided at an uppermost stage, and the dummy body functions as an acoustic matching layer. The ultrasonic transducer according to claim 1,
The ultrasonic transducer according to claim 1, wherein the dummy body is provided at a lowermost stage, and the dummy body functions as a backing layer or a backing-side acoustic matching layer. A first electrode forming step of forming a surface electrode between each member of the plurality of piezoelectric bodies and the dummy body;
After the surface electrode is formed, a laminating step of laminating a plurality of piezoelectric bodies and dummy bodies to form a laminated body,
A second electrode forming step of forming an electrode so as to surround the laminate;
An insulation treatment step of performing an insulation treatment for alternately distributing a plurality of surface electrodes from the upper surface electrode to the lower surface electrode of the laminate to the positive electrode and the negative electrode;
The manufacturing method of the ultrasonic transducer | vibrator characterized by the above-mentioned. The apparatus of claim 5.
In the insulation treatment step, a pretreatment step of insulating one end portion of the surface electrode between the members before the lamination step, and a top electrode and a bottom electrode of the laminate after the second electrode formation step And a post-processing step of insulating one end of the ultrasonic transducer.

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