JPH10282074A - Backing material for probe and manufacture for ultrasonic probe and ultrasonic probe using the material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backing material for probes which fully absorbs ultrasonic waves emitted from a rear face of a piezoelectric element, thereby preventing reflection, serves also to take out an electrode, achieves sure electric connection and enhances workability and, an ultrasonic probe using the material. SOLUTION: A plurality of bamboo blind-like metallic thin plates having many unit conduction electrodes 8 extended from a coupling part 7 are disposed in parallel in a backing material 3. The coupling part of the bamboo blind-like metallic thin plates is exposed to a surface of the backing material. Extended end parts of the unit conduction electrodes are exposed or projected to an outer surface except for the surface of the backing material. The backing material 3 for probes is constituted in this manner. A piezoelectric plate is fixed onto the surface of the backing material, which is divided in a first dimensional and a second-dimensional directions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backing material for a probe, a method of manufacturing an ultrasonic probe using the same, and a field of application of the ultrasonic probe. The present invention relates to a 1.5D-type ultrasonic probe (short-axis variable probe) in which an opening area in the same direction can be varied by also dividing an element length direction.

[0002]

[Prior art]

(Background of the Invention) An ultrasonic probe is useful as an ultrasonic transmitting and receiving unit of an ultrasonic diagnostic apparatus for medical use or the like. For example, an array type in which strip-shaped piezoelectric elements are arranged in the width direction is electronically scanned by linear or sector drive or the like. Array direction (long axis direction)
To obtain a decomposed image of And, in such a thing, the short axis variable probe divides the length direction of the piezoelectric element into a plurality of piezoelectric elements, and connects the piezoelectric elements to change the opening area thereof as necessary for diagnosis, The focus in the depth direction of the object to be detected is switched to improve the resolution in the same direction (refer to Japanese Patent Laid-Open No. 62-2799).
And JP-A-4-119800).

(Example of Prior Art) FIG. 11 is a plan view of a short-axis variable probe showing an example of the prior art. The short axis variable probe is configured by arranging a plurality of strip-shaped piezoelectric elements 1 made of, for example, PZT (lead zirconate titanate) in the long axis direction (the width direction of the piezoelectric element 1), and further, for example, by connecting the piezoelectric elements 1 to each other. In the short axis direction (the length direction of the piezoelectric element 1), the central portion and the three
It is divided into two piezoelectric elements (abc). The piezoelectric element 1 has electrodes on both main surfaces, a back surface is fixed on a backing material, and an acoustic matching layer and an acoustic lens having a curvature in the short axis direction are laminated on the front surface side (not shown). The electrodes on the front side are commonly connected, and signal lines are led out from the back side for each piezoelectric element.

In such a device, as described above, the piezoelectric element 1 is driven, for example, in the long axis direction by, for example, a sector. And
In the short axis direction, for example, when performing diagnosis near the surface of the detection target, only the piezoelectric element 1a at the center is driven, thereby reducing the aperture area (D1) and shortening the focal length (f1). Then, "FIG. 12 (a)" improves the resolution in the same area. Further, when performing a diagnosis in a deep part of the body, the piezoelectric elements 1 (abc) at the central part and both ends are commonly connected and driven simultaneously, thereby opening area (D2)
Is increased to increase the focal length (f2) (FIG. 12 (b)) to improve the resolution in the same area. Note that P in the drawing is an electric pulse applied to the piezoelectric elements 1 (a) and 1 (abc).

[0005]

[Problem to be Solved by the Invention]

(Problems of the prior art) However, in the short axis variable probe as described above, since the piezoelectric elements 1 (abc) are two-dimensionally arranged, it is difficult to derive the drive electrodes on the back side. Was. That is, after the piezoelectric plate is fixed on the backing material, when dividing the piezoelectric plate, the drive electrodes at both ends of the piezoelectric element 1 (abc) can be easily led out using, for example, a flexible printed circuit board, but the drive at the center portion is performed. There was a problem that the electrode could not be easily derived.

For this reason, as described in, for example, the above-mentioned Japanese Patent Application Laid-Open No. 62-2799, the connection electrode 5 is provided on the upper end surface of the substrate 2a, and the conductive path 5a extends on the main surface. A backing material 3 is provided between the plurality of printed wiring boards 2. Then, the piezoelectric plate 4 is fixed to the upper end surface (front surface) of the piezoelectric element 1 (abc) on the rear surface side of each piezoelectric element 1 (abc) by fixing the piezoelectric plate 4 with a conductive adhesive. (Not shown) derived from the connection electrode 5 and the conductive path 5a (FIGS. 13 and 14). FIG. 13 is an assembly view, and FIG. 14 is a side view in the short axis direction.

However, in such a case, the piezoelectric element 1
On the back side of (abc), a printed wiring board 2 is disposed in addition to the backing material 3 for preventing reflected waves due to scattering and absorption. For this reason, the reflected wave of the ultrasonic wave radiated from the back surface side of the piezoelectric plate element 1 is generated by the printed wiring board 2. Further, there is a problem that the area ratio of the printed wiring board 2 to the backing material 3 is large, the reflected wave cannot be attenuated by the backing material 3, and the reflected wave reaches the piezoelectric element 1 (abc) and adversely affects the ultrasonic characteristics. there were.

Further, the surfaces of the printed wiring board 2 and the backing material 3 are not always the same (flat surface), and the thickness of the conductive adhesive becomes uneven when the piezoelectric plate 4 is fixed. Therefore, in the portion where the thickness of the conductive adhesive is large, there is a problem that a reflected wave or a variation occurs as described above, which adversely affects the ultrasonic characteristics.

In the above-mentioned Japanese Patent Application Laid-Open No. 4-119800, a large number of wires (metal wires) 16 are arranged in a jig box 17 so that the backing material 3 flows in and is solidified, and the tip of the wire 16 is exposed on the surface. I do. Then, a piezoelectric plate (not shown) is fixed with, for example, a conductive adhesive and then cut in one-dimensional and two-dimensional directions to obtain each piezoelectric element (FIG. 15 (ab)). However, in such a device, there is a problem in that the electrical conductivity is impaired because the electrode of each piezoelectric element and the wire are in point contact.
Furthermore, since the disjointed wires are arranged one by one in the jig box, there is a problem that the workability is difficult.

(Object of the Invention) The present invention is to improve the workability by sufficiently absorbing the ultrasonic wave radiated from the back side of the piezoelectric element to prevent reflection, and also to lead out the electrodes and to ensure the electrical conduction. An object of the present invention is to provide a favorable backing material for a probe and an ultrasonic probe using the same.

[0011]

SUMMARY OF THE INVENTION According to the present invention, there is provided a probe backing material in which a number of unit conducting electrodes are extended in parallel from a connecting portion and interdigitated metal thin plates are interposed in the backing material. The basic solution is to form an ultrasonic probe using the probe backing material.

[0012]

According to the present invention, since the interdigital metal sheets are interposed in the backing material in parallel, the area ratio of the row-shaped metal sheets to the backing material is reduced. Further, even if the piezoelectric plate is divided into individual piezoelectric elements, the piezoelectric elements and the unit conductive electrodes are in line contact. Further, since the unit conductive electrodes are integrated by the connecting portion, the handling is facilitated. Hereinafter, the present invention will be described in detail with reference to an example.

[0013]

1 and 2 show an embodiment of the present invention (FIG. 1).
FIG. 1 is a perspective view of a backing material for a probe, FIG. 2 (a) is a view from the front side, and FIG. 2 (b) is a view from the back side. .

The probe backing material 6 is formed of the backing material 3 and a plurality of (three) interdigital metal sheets 5. The backing material is made of a rubber-based resin mixed with metal particles and the like as in the related art, and has a function of scattering and absorbing ultrasonic waves to prevent reflected waves. The interdigital metal sheet 5 is provided in the backing material 3 with its plate surfaces facing each other in parallel, and includes a connecting portion 7 and a plurality of unit conducting electrodes 8 extending in an interdigital manner from the connecting portion 7. These are formed integrally by, for example, etching or pressing. Then, the connecting portion 7 is placed on the surface of the backing material 3 and the unit conducting electrode 8
Is exposed on the back surface of the backing material 3.

In this example, the molten backing material 3 flows into a jig box (not shown) in which the interdigital metal sheets 5 are arranged in parallel and solidifies, and the interdigital metal sheets 5 are placed in the backing material 3. Is embedded and integrated (FIG. 3). Alternatively, an individual unit backing material 3 (not shown) is formed and bonded to the interdigital metal sheet 5 by bonding. However, here, the extending ends of the unit conductive electrodes 8 of the interdigitated metal sheet 5 are connected by a lower end connecting portion 9 to increase the strength.
In any case, a plurality of interdigital metal sheets 6 are embedded in the backing material 3 in parallel.

Next, the surface side of the backing material 3 is scraped by polishing or the like to make it flat, and the upper end connecting portion 7 of the interdigital metal sheet 5 is exposed on the surface. In addition, the lower end connecting portion 9 is also scraped off on the back side by the same polishing, and the extended end portion of the unit lead-out electrode 8 is exposed to form (see FIG. 2).

FIGS. 4 to 6 show a method of manufacturing a short axis variable probe using such a backing material for a probe (see FIG. 2).
FIG. The ultrasonic probe is formed by attaching a piezoelectric plate 4 having electrodes (not shown) on both main surfaces to a conductive adhesive 10 on the surface of the above-described probe backing material 6.
(Fig. 4).

Then, the upper end connecting portion 7 is cut together with the piezoelectric plate 4 from the top of the piezoelectric plate 4 by, for example, a dicing saw to form a cut to the backing material 3.
Divided into That is, FIG. 5A divides the piezoelectric plate 4 in a one-dimensional direction (long axis direction). Then, the cutting direction is changed by 90 degrees to cut the interdigital metal sheet 5 from above the piezoelectric plate 4 to form a cut reaching the backing material 3 and divide the piezoelectric element 1 (abc). That is, the piezoelectric plate 4
Is also divided into two-dimensional directions (shorter axis directions) (FIG. 5B). After cutting in the short axis direction first, the long axis direction may be cut.

In this way, a short axis variable probe is obtained which is divided in the major axis and the minor axis directions and has the end of the interdigital electrode 8 exposed on the back surface (FIG. 6). FIG. 6A is a view from the front side, and FIG. 6B is a view from the back side. On the back surface of the short axis variable probe (probe backing material 6), for example, a flexible substrate 13 having a terminal portion 12 extending from the conductive path 11 exposed on the surface is connected by soldering or the like. The electrode on the back side of the element 1 (abc) is led out (the seventh electrode).
Figure). The electrodes on the front side are connected to the same potential by a lead wire, a conductive adhesive, or the like, and an acoustic matching layer and an acoustic lens are laminated (not shown). After the piezoelectric plate 4 is cut, the piezoelectric plate 4 may be formed into a curved surface such as a convex (convex) or a concave (concave).

With such a configuration, the probe backing material 10 is connected to the unit conductive electrode 8 with respect to the backing material 3.
, The backing effect can be enhanced as a whole. Further, the surface is ground by polishing or the like to expose the upper end connecting portion 7 of the electrode lead-out metal plate 5, so that the surface is flattened, and the thickness of the conductive adhesive 10 is made uniform when the piezoelectric plate 4 is fixed. Therefore, it is possible to sufficiently scatter and absorb the ultrasonic waves radiated from the back surface side of the piezoelectric element 1, suppress the reflected waves, and prevent the influence.

Even when the piezoelectric plate 4 is divided into individual piezoelectric elements, the piezoelectric elements 1 (abc) and the unit conductive electrodes 8 are in line contact. Therefore, the piezoelectric element 1
The electrical connection between the drive electrode (abc) and the unit conductive electrode 8 is ensured as compared with the above-mentioned point contact.

Further, since each unit conductive electrode 8 is integrated by the connecting portion 7, its handling is facilitated. Therefore, when aligning each unit conducting electrode 8 in the jig box, or when interposing each unit bucking material,
Increase its workability.

[0023]

[Other Embodiments] In the above embodiment, the connecting portion 7 of the interdigitated metal sheet 5 was exposed to form the backing material 6 for the probe.
For example, when the surface of the backing material 3 is polished, the upper end connecting portion 7 may be removed to provide the probe backing material 6. In short, in a state where the connecting portion 7 of the interdigital metal plate 5 is removed,
A large number of unit conducting electrodes 8 are arranged in a row in the form of a thin metal plate, and they are interposed in parallel in the backing material 3. It may be exposed or protruded (corresponding to the invention of claim 3).

Also, an ultrasonic probe may be manufactured using such a backing material for a probe.
Of the invention). That is, the piezoelectric plate 4 electrically connected to one end of the unit conductive electrode 8 is fixed on the surface of the probe backing material 6, and the unit conductive electrode 8 and the row-shaped metal sheet are cut from above. Thus, the piezoelectric plate 4 may be divided in one-dimensional and two-dimensional directions (not shown).

Further, as the ultrasonic probe, regardless of the manufacturing method of the above-described embodiment, as a result, a plurality of row-shaped metal thin plates composed of a large number of unit conducting electrodes 8 are interposed in parallel in the backing material. One end of the unit conductive electrode 8 is exposed on the surface of the backing material, and the individual piezoelectric element 1 (abc) is fixed on the surface of the backing material in electrical line contact with the one end of the unit conductive electrode 8. And the other end of the unit conductive electrode 8 is exposed or protruded from the outer surface excluding the surface of the backing material 3 (claim 5).
Has the same effect as the embodiment, and belongs to the technical scope of the present invention.

[0026]

[Other matters] In the above embodiment, the backing material 6 for the probe is used.
The flexible substrate 13 is connected to the back of
For example, a connector consisting of a printed board 15 or the like provided with the terminal portion 12 and the lead terminal 14 may be connected (FIG. 9), and the connection form can be arbitrarily set.

The extended end (the other end) of the unit conductive electrode 8 is exposed on the back side of the probe backing material 6, but the extended end is projected from the back side (FIG. 9). , Terminals with holes in flexible or printed circuit boards (not shown)
May be connected, and the connection form can be arbitrarily determined as described above.

Although the extended end of the unit conductive electrode 8 is exposed or protruded from the back side of the probe backing material 6, any outer peripheral surface excluding the surface of the backing material 3 may be used. Further, the back surface side of the probe backing material 6 is not necessarily a flat surface, but may be, for example, a step-like shape.

In the short axis direction, three piezoelectric elements 1 are provided.
Although it is divided into (abc), it is needless to say that it may be divided into any number larger than this. Although the short axis variable probe has been described, it is needless to say that the present invention can be applied to a matrix probe. And the piezoelectric element electrically connected by line contact basically belong to the technical scope of the present invention.

[0030]

According to the present invention, a backing material for a probe is formed by interposing a plurality of interdigital metal thin plates having a large number of unit conducting electrodes extending from a connecting portion in parallel in the backing material. Since the acoustic probe is configured, it is possible to sufficiently absorb the ultrasonic wave radiated from the back surface side of the piezoelectric element to prevent the reflection, and to ensure the electrical conduction to improve the workability.

[Brief description of the drawings]

FIG. 1 is a perspective view of a probe backing material for explaining an embodiment of the present invention.

FIGS. 2A and 2B are diagrams of a backing material for a probe for explaining an embodiment of the present invention, wherein FIG. 2A is a diagram viewed from the front side, and FIG. is there.

FIG. 3 is a perspective view of a probe backing material for explaining an embodiment of the present invention.

FIG. 4 is a view illustrating a short-axis variable probe using the probe backing material according to the present invention, and is an assembly diagram in which a piezoelectric plate is fixed on the probe backing material.

5A and 5B are diagrams illustrating a short-axis variable probe using the backing material for a probe according to the present invention, wherein FIG. 5A is a cross-sectional view in the short-axis direction, and FIG. FIG.

6A and 6B are diagrams illustrating a short-axis variable probe using the probe backing material according to the present invention, wherein FIG. 6A is a diagram viewed from the front side, and FIG. FIG.

FIG. 7 is a view for explaining a short-axis variable probe using the probe backing material according to the present invention, and is an assembly drawing for connecting to a flexible printed circuit board.

FIG. 8 is a cross-sectional view illustrating a short axis variable probe using the probe backing material according to the present invention.

FIG. 9 is a diagram illustrating a short-axis variable probe using the probe backing material according to the present invention, and is a diagram of a printed circuit board.

FIG. 10 is a sectional view showing another example of the probe backing material according to the present invention.

FIG. 11 is a plan view of a short-axis variable probe explaining a conventional example.

FIG. 12 (ab) is a cross-sectional view of a short-axis variable probe for explaining the operation of the conventional example.

FIG. 13 is an exploded view of a short axis variable probe for explaining a conventional example.

FIG. 14 is a cross-sectional view of a short-axis variable probe explaining a conventional example.

15A and 15B are diagrams illustrating a conventional example. FIG. 15A is a diagram of a jig box for producing a probe backing material, and FIG. 15B is a diagram of a probe backing material. is there.

[Brief description of reference numerals]

1 piezoelectric element, 2 printed wiring board, 3 backing material, 4 piezoelectric plate, 5 connection electrode, 6 piezoelectric plate for probe,
7 connection part, 8 unit conduction electrode, 9 lower end connection part, 10
Conductive adhesive, 11 conductive path, 12 terminal, 13
Flexible board, 14 terminals, 15 printed circuit board,
16 wires, 17 jig box.

Claims (5)

[Claims] A plurality of interdigitated metal thin plates having a plurality of unit conducting electrodes extending from a connecting portion are interposed in parallel in a backing material to expose a connecting portion of the interdigital metal plates on the surface of the backing material. A backing material for a probe, wherein an extended end portion of the unit conductive electrode is exposed or protrudes from an outer surface excluding a surface of the backing material. 2. A piezoelectric plate which is electrically connected to a connection portion of said interdigital metal plate is fixed on a surface of said probe backing material according to claim 1, and said piezoelectric plate and said piezoelectric plate are joined together from above said piezoelectric plate. The piezoelectric plate is divided in a one-dimensional direction by cutting a connecting portion of a metal sheet, and the piezoelectric plate is divided in a two-dimensional direction by cutting between the interdigital metal sheets from above the piezoelectric plate. Method of manufacturing an ultrasonic probe. 3. A plurality of united conducting electrodes extending from a connecting portion with a plurality of interdigital metal plates interposed in parallel in a backing material, and grinding the surface of the backing material to connect the interdigital metal plates. The end portion of the unit conductive electrode is exposed while the row-shaped thin metal plate is removed, and the extended end portion of the unit conductive electrode is exposed or protruded on the outer surface excluding the surface of the backing material. Backing material for the probe. 4. A piezoelectric plate electrically connected to one end of said unit conductive electrode is fixed on a surface of said probe backing material according to claim 3, and between said unit conductive electrodes and from above said piezoelectric plate. A method of manufacturing an ultrasonic probe, comprising cutting a row of thin metal plates and dividing the piezoelectric plate in one-dimensional and two-dimensional directions. 5. A plurality of row-shaped thin metal plates comprising a plurality of unit conductive electrodes are interposed in parallel in a backing material, and one end of the unit conductive electrode is exposed on a surface of the backing material. Individual piezoelectric elements that are in electrical line contact with one end of the unit conductive electrode are fixed on the surface and arranged in one-dimensional and two-dimensional directions, and the unit conductive electrode on the outer surface except for the surface of the backing material is fixed. An ultrasonic probe characterized in that the other end is exposed or protruded.