JPH0638297A - Manufacture of ultrasonic wave probe - Google Patents

Abstract

PURPOSE:To realize an inverted polarization ultrasonic wave prove and a high density paper-tablet vibrator. CONSTITUTION:A comb-line vibrator 2 is obtained by applying groove-cutting to one side of a piezoelectric body polarized uniformly at an arrangement pitch 2P being twice an arrangement pitch P with a blade whose width is nearly equal to the arrangement pitch P. Other comb-line vibrator 2 obtained by the similar procedure is fitted to the vibrator 2 above with each other, and in order to obtain the part having the arrangement pitch P, the piezoelectric body 1 is cut till the arrangement part having the arrangement pitch P from the upper and the lower part. Electrodes are provided to both sides obtained to form an arrangement vibrator 5. As a result, the arrangement pitch of the vibrator is doubled, a conventional probe, a high density composite piezoelectric body and an inverted polarization arrangement vibrator are easily obtained and a high performance probe is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe of an ultrasonic device for measuring and observing an object with ultrasonic waves.

[0002]

2. Description of the Related Art In a conventional ultrasonic transducer, as shown in FIG. 6, a piezoelectric body 1 is uniformly polarized and cut to form an array transducer. The electrodes 10 are formed on each of the array transducers, the signal line 11 is drawn out from each array transducer, the phase is given and driven, and the phase is added to the received signal and added to scan the ultrasonic wave. Further, in order to create the array vibrator, the flat vibrator was cut with a dicing saw or the like. Furthermore, as a composite piezoelectric body in which a large number of columnar vibrators are embedded in an organic material, piezoelectric composite materials for ultrasonic transducer applications (piezo composite materi
als for ultrasonic transducer applications), IEEE sonics and ultrasonic 32 volumes (IEEEsonics and ultrasonic
s vol.su-32, no.4, July, 1985), Properties of Composite Piezoelectric Materials for Ultrasonic Transducers (
properties of composite piezoelectric materials fo
Ultrasonics Symposium (1984) (Ultrasonics sympo)
1984), and a method for producing a piezoelectric body having this structure is described in JP-A-60-85699.

[0003]

In the above-mentioned prior art, the signal lines are required in the same number as the arrayed vibrators. Further, a large number of transmission / reception circuits are required, and there is a problem in forming a miniaturized probe and miniaturizing the probe device. In addition, the array pitch P of array transducers becomes smaller as the frequency becomes higher, and a very thin cutting blade and a very advanced cutting technique are required. Conventionally, it is very difficult to set the pitch P to 90 μm or less. It has been almost impossible to realize a high frequency probe such as an electronic sector probe of 10 MHz or more. Furthermore, it is difficult to arrange the columnar vibrators at a fine pitch even in the composite piezoelectric body, and the arrangement pitch is still limited to about 90 μm. An object of the present invention is to provide a method for manufacturing an inverted polarization ultrasonic probe and a high-density strip-shaped oscillator, which solves the problems of the conventional techniques.

[0004]

A burst wave is applied between electrodes as a common electrode using an inverted polarization array oscillator, and an ultrasonic beam is scanned by sweeping the frequency of the burst wave. In order to realize an inverted polarization array oscillator, a groove is formed on one side of a uniformly polarized piezoelectric body to form a comb-shaped piezoelectric body having a structure in which a large number of strip-shaped oscillators are connected on one side. A comb-shaped piezoelectric body is formed by similarly forming a groove on one surface of the prepared uniformly polarized piezoelectric body, and the concave and convex portions of both comb-shaped piezoelectric bodies are fitted and adhered to each other to form a monolithic piezoelectric body. And Both sides of this one-piece piezoelectric body are ground to form strip-shaped vibrators. At this time, the surfaces on which the grooves are formed have the same polarization direction as that of the two piezoelectric bodies, uniform electrodes are provided on both surfaces of the arrayed piezoelectric bodies, and they are bonded onto an acoustic support called a backing material. To be achieved.

That is, a step of forming a comb-shaped piezoelectric body having a structure in which a groove is formed on one surface of a piezoelectric body and a large number of strip-shaped vibrators are connected on one side, and two comb-shaped bodies formed by this step are formed. It is characterized by comprising the steps of fitting the concave and convex portions of the piezoelectric body together and adhering them to form an integral structure piezoelectric body, and grinding both sides of this integral structure piezoelectric body to form a strip-shaped vibrator. This is a method for manufacturing a sound wave probe. The surface on which the groove is formed is the surface of the two piezoelectric bodies in the same polarization direction.
An ultrasonic probe that scans an ultrasonic beam by applying a burst wave between the uniform electrodes and sweeping the frequency of the burst wave Get a child Further, the surfaces forming the grooves may be surfaces having different polarization directions in the two piezoelectric bodies.

Further, a step of forming a comb-shaped piezoelectric body having a structure in which a groove is formed on one side of the piezoelectric body and a large number of strip-shaped vibrators are connected on one side, and the groove of the comb-shaped piezoelectric body is filled with an organic substance. And a step of forming a groove in a comb-shaped piezoelectric body filled with an organic material in a direction different from the groove, and by fitting the concave portion and the convex portion of the comb-shaped piezoelectric body having a groove formed in the different direction. A composite comprising a step of adhering to form an integrated structure and a step of grinding both surfaces of the integrated structure piezoelectric body to form a composite piezoelectric body having a structure in which a large number of columnar vibrators are embedded in an organic substance. A method for manufacturing an ultrasonic probe made of a piezoelectric material.

[0007]

Function: A comb-shaped piezoelectric body is formed by forming a groove on one side of a uniformly polarized piezoelectric body, and a groove is similarly formed on one side of a uniformly polarized piezoelectric body prepared separately. A piezoelectric body is formed, and the concave and convex portions of both of these are fitted and bonded together, and the both sides are ground to form an array configuration.
Both piezoelectric bodies can have the same polarization plane,
The polarization directions can be alternated. By applying this manufacturing method, it is possible to double the array pitch of the oscillators,
Higher densities can be achieved than with conventional probes and composite piezoelectric bodies. In the ultrasonic probe using such an inverted polarization array transducer, the ultrasonic beam can be scanned with a small number of signal lines, so that a finer ultrasonic probe can be realized. Further, by applying this method of forming the inverted polarization array oscillator, the limits of the array pitch of the conventional electronic scanning probe and the array pitch of the composite piezoelectric body can be exceeded.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a method of manufacturing an ultrasonic probe which is a first embodiment of the present invention. The arrow indicates the polarization direction. Assuming that the array pitch is P from one surface of the polarized piezoelectric body 1, a comb-shaped vibrator is formed by grooving with a blade having a width of approximately P at an array pitch that is double. The depth of the groove is made deeper than the thickness of the vibrator finally required, and the groove width G is made larger than the width W of the convex portion of the vibrator. As shown in FIG. 1B, the comb-shaped vibrator 2 obtained in exactly the same manner is fitted with the concave portion and the convex portion and bonded. At this time, regarding the groove width, a clearance for fitting, a margin for adhesion, and the like are taken into consideration. Then, as shown in FIG.
The upper and lower parts shown in (b) are cut to the array part. Further, electrodes 9 and 10 are provided on both surfaces, and the electrodes 9 and 10 are bonded to an acoustic support 8 called a backing material to form the inverted polarization array probe shown in FIG. The front surface of the probe (the surface facing the acoustic support 8) is usually covered with the acoustic matching layer and the protective film, but it is omitted in FIG. When a burst wave is applied between the electrodes 9 and 10 as shown in FIG. 3, the emission angle (θ) can be scanned by the transducer pitch P and the driving frequency f. In this way, since the radiation angle (θ) changes depending on the frequency, the ultrasonic beam can be scanned. In addition, after cutting from the upper portion of the state shown in FIG. 1 (b) to expose one convex portion of the comb-shaped vibrator, a plurality of pieces are formed at a predetermined pitch and width in a direction substantially orthogonal to the direction of the comb blade. It is possible to manufacture a domain-inverted array oscillator composed of a composite having flexibility in one direction by inserting the groove of the above, filling the groove with an organic substance such as polyurethane, and then cutting off from the lower side. In the above embodiments, an example in which the piezoelectric body is mechanically processed has been described, but it is also possible to alternate the polarization by the electrode pattern. The piezoelectric body is PZ
A ceramic such as T or an organic piezoelectric material may be used. Further, although the example in which the polarization is alternated has been described, the same applies to the expansion to the irregular array.

FIG. 4 shows a method of manufacturing a high-density strip-shaped vibrator according to a second embodiment of the present invention. The array pitch of the conventional electronic scanning probe is limited to about 90 μm. However, by applying the manufacturing method of FIG. 1, the array pitch of the strip-shaped vibrators can be halved, and a probe with higher density can be realized. For example, an electronic sector probe having a frequency of 10 MHz or more can be realized. Similar to the case of FIG. 1A, in FIG. 4A, the arrangement pitch P of the strip-shaped vibrators to be formed from one surface of the polarized piezoelectric body 1 is 2
Form a groove with a blade of about P width at double pitch,
Form a comb-shaped oscillator. The depth at this time is made deeper than the thickness of the vibrator finally required, and the groove width G is made larger than the width W of the convex portion of the vibrator. Next, the comb-shaped vibrator 2 is formed by grooving so that the polarization direction is opposite to that of the comb-shaped vibrator 1.
As shown in FIG. 4B, the concave and convex portions are fitted to each other, and the clearances 3 and 4 are bonded. At this time, unlike FIG. 1B, the polarization directions are the same. Thereafter, as shown in FIG. 4C, the upper and lower portions shown in FIG. 4B are cut off to obtain the strip-shaped vibrator 5. Next, the electrodes are formed on the upper and lower surfaces, the electrodes on the signal electrode side are formed in an array and adhered to the backing material,
A probe can be realized by forming an acoustic matching layer, a protective film, etc. on the acoustic radiation surface side and further mounting an acoustic lens or the like. In the prior art, a vibrator is bonded to a backing material and a strip-shaped vibrator is formed so that a groove is formed in the whole vibrator. In such a method, for example, a blade of about 20 μm is used and about 90 μm is used. It was the limit to make a groove. It is considered that this is because the groove is formed in two kinds of materials, that is, the piezoelectric material and the backing material, the cutting conditions are bad, and the blade is thin so that the blade cannot be precisely cut due to the vibration of the blade. Further, if the blade width is made thicker, the width of the strip-shaped vibrator also becomes smaller, which causes a problem that the vibrator is chipped at the time of cutting. It is said that the blade width is limited to about 10 μm.
As described above, the conventional method has various restrictions and problems, and it has been impossible to arrange the strip-shaped vibrators at a high density of 90 μm or less. According to the method shown in FIG. 4, the piezoelectric body alone can be grooved, and the pitch and blade width at the time of cutting can be increased, so that the density of the strip-shaped vibrator can be increased. For example, using the method shown in FIG.
When grooving is performed at a pitch of 0 μm, G slightly expands to about 60 μm and W becomes about 40 μm due to the vibration of the blade, and the strip vibrator finally formed has a pitch of 50 μm and the gap between the strip vibrators is about 50 μm. It becomes about 10 μm.
As described above, by the method shown in FIG. 4, it is possible to easily manufacture a strip-shaped vibrator having a fine pitch, which cannot be realized by the conventional technique.

FIG. 5 shows a method of manufacturing a high density composite piezoelectric material according to a third embodiment of the present invention. FIG. 5 (a) is shown in FIG.
4A shows a state in which a comb-shaped piezoelectric body is formed in the same manner as in FIG. 4A and is further filled with the organic substance 6 to fill the cutting groove. In FIG. 5B, the groove 3 is formed in the direction orthogonal to the groove formed first. The state 13 of FIG. 5B will be referred to as a composite comb piezoelectric body. FIG. 5C shows FIG.
FIG. 7B is a view seen from the direction A, showing a state in which the composite comb-shaped piezoelectric bodies 14 and 13 similar to 13 are stuck and adhered. FIG. 5D shows a state in which unnecessary piezoelectric elements on the upper and lower surfaces of FIG. 5C are shaved to form a composite piezoelectric body 7 in which a large number of columnar vibrators 12 are connected by an organic substance 6. As in the case of FIG. 4, the composite piezoelectric body of FIG. 5 can have a finer pitch than conventional. It is flexible because it is connected by organic substances. In the embodiment, a polarized piezoelectric material is used, but it is also possible to finally polarize, and the composite piezoelectric material of FIG. 5 can be manufactured by changing the polarization direction in various ways.

[0011]

According to the present invention, an inverted polarization array oscillator, which has been difficult to achieve in the past, can be easily realized. Further, since the ultrasonic beam can be scanned with a small number of signal lines by using the ultrasonic probe formed by this vibrator, a finer ultrasonic probe can be realized. Furthermore, by developing this method of creating an inverted polarization array transducer, the array pitch of the transducers can be doubled, and it is possible to easily realize the high density of the conventional probe and the composite piezoelectric body. Can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view showing a method of manufacturing an ultrasonic probe according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an ultrasonic probe according to a first embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a drive frequency and a sweep angle in an inverted polarization array oscillator.

FIG. 4 is a perspective view showing a method of manufacturing a high-density strip-shaped vibrator according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a method of manufacturing a high-density composite piezoelectric body according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a conventional ultrasonic probe.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric body, 2 ... Comb-like vibrator, 3 ... Gap, 4 ... Gap, 5 ... Strip-shaped vibrator, 6 ... Organic substance, 7 ... Composite piezoelectric body,
8 ... Acoustic support (backing), 9 ... Electrode, 10 ... Electrode, 11 ... Signal line, 12 ... Columnar vibrator, 13 ... Composite comb-shaped piezoelectric body, 14 ... Composite comb-shaped piezoelectric body.

Front Page Continuation (72) Inventor Narendra Sangbi 1-280, Higashi Koikekubo, Kokubunji City, Tokyo Inside Hitachi Central Research Laboratory

Claims (6)

[Claims] 1. A step of forming a comb-shaped piezoelectric body having a structure in which a groove is formed on one surface of a piezoelectric body and a large number of strip-shaped vibrators are connected on one side, and two comb-shaped bodies formed by this step. It is characterized by comprising the steps of fitting the concave and convex portions of the piezoelectric body together and adhering them to form an integral structure piezoelectric body, and grinding both sides of this integral structure piezoelectric body to form a strip-shaped vibrator. Method for manufacturing acoustic wave probe. 2. The surface forming the groove is a surface of the two piezoelectric bodies in the same polarization direction.
A method for manufacturing the ultrasonic probe described in. 3. The method of manufacturing an ultrasonic probe according to claim 1, wherein uniform electrodes are provided on both surfaces of the strip-shaped vibrator. 4. An ultrasonic probe manufactured by the method for manufacturing an ultrasonic probe according to claim 3, wherein a burst wave is applied between the uniform electrodes. The ultrasonic probe according to claim 3, wherein the ultrasonic beam is scanned by sweeping the frequency of the strike wave. 5. The method of manufacturing an ultrasonic probe according to claim 1, wherein the surface forming the groove is a surface having different polarization directions in the two piezoelectric bodies. 6. A step of forming a comb-shaped piezoelectric body having a structure in which a groove is formed on one side of a piezoelectric body and a large number of strip-shaped vibrators are connected on one side, and the groove of the comb-shaped piezoelectric body is filled with an organic substance. And a step of forming a groove in a comb-shaped piezoelectric body filled with an organic material in a direction different from the groove, and by fitting the concave portion and the convex portion of the comb-shaped piezoelectric body having a groove formed in the different direction. It is characterized by comprising a step of adhering to form an integrated structure and a step of grinding both surfaces of the integrated piezoelectric body to form a composite piezoelectric body having a structure in which a large number of columnar vibrators are embedded in an organic substance. A method for manufacturing an ultrasonic probe made of a composite piezoelectric material.