JP3494578B2 - Ultrasonic probe and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an application field of an ultrasonic probe in which piezoelectric elements are two-dimensionally arranged, and in particular, an array type short axis direction (length direction of piezoelectric element) is also divided. 1.5D (Dimention) with variable opening area in the same direction
The ultrasonic probe of the type (1.5D probe).

[0002]

(Background of the Invention) An ultrasonic probe is useful as an ultrasonic wave transmitting / receiving section of an ultrasonic diagnostic apparatus for medical purposes. For example, an array type in which strip-shaped piezoelectric elements are arranged side by side in the width direction is electronically scanned by linear or sector drive, etc., so that the ultrasonic diagnostic apparatus can decompose an image in the array direction (long axis direction) in a diseased part or the like. To get The 1.5D 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 to change the opening area according to the need of diagnosis. The focus of the direction is switched to improve the diagnostic efficiency. One of these is the 1.5D probe by the present applicant (see Japanese Patent Application No. 9-98312).

(One Example of Prior Art) FIG. 10 is a plan view of a 1.5D probe for explaining one conventional example of this type.
The 1.5D probe is formed by arranging the piezoelectric elements 1 composed of three piezoelectric elements 1 (abc) divided in the short axis direction in the long axis direction. In such a structure, since the piezoelectric element 1 is divided into three in the short axis direction, for example, if only the central piezoelectric element 1a is driven, the depth of focus can be reduced and the vicinity of the surface of the living body can be diagnosed. When the piezoelectric elements 1 (abc) on the center and both sides are electrically connected in common and driven, the depth of focus can be increased and the deep part of the living body can be diagnosed.

11 to 13 are referred to as 1.
It is a figure explaining a 5D probe. In this proposed example, a plurality of thin metal plates 4 as signal derivation bodies, which are composed of a large number of signal lines 3 in the backing material 2, are embedded in the backing material with their plate surfaces parallel to each other (Fig. 11, signal. Track 3
Are commonly connected by the connecting portion 5. Next, the surface of the backing material 2 is exposed by polishing or the like. Then, the piezoelectric plate 7 having the electrodes 6 (ab) on both main surfaces is fixed to the surface of the backing material 2 by a conductive adhesive 8 not shown here (FIG. 12). Next, the space between the signal lines 3 is cut from above the piezoelectric plate 7 and divided into a large number of piezoelectric elements 1 together with the connecting portion 5 (FIG. 13 (a)). Further, the space between the metal thin plates 4 is cut from above the piezoelectric plate 7 to divide the piezoelectric element 9 into three piezoelectric elements 1 (abc) (FIG. 13 (b)).
In short, the piezoelectric plate 7 is divided into two-dimensional directions to obtain piezoelectric elements arranged in a matrix. Then, a method of individually deriving electrodes from each piezoelectric element is proposed.

[0005]

Problems to be Solved by the Invention (Problems of Prior Art)
However, in such a structure, since the backing material 2 and each piezoelectric element 1 are fixed by the conductive adhesive 8, there is a problem that the bonding strength between the two is small and the piezoelectric element 1 is peeled off. That is, the conductive adhesive 8 has a weak adhesive strength because particles of silver or the like are mixed in the adhesive matrix, and the backing material 2 generally contains a rubber-based resin as a main component. The degree of adhesion is poor. Then, the backing material 2 is mechanically deformed due to a pressing force (shock) during use, a thermal shock during disinfection, or the like, so that the state between the interface with the conductive adhesive 8 is changed, causing peeling. There was a problem. However, the conductive adhesive 8 can simultaneously fix and electrically connect the backing material 2 exposing the thin metal plate 4 and the piezoelectric plate 7, which is very convenient in terms of work.

(Object of the Invention) An object of the present invention is to provide an ultrasonic probe which maintains the bonding strength between a backing material and a piezoelectric element while maintaining the convenience of a conductive adhesive, and a method for manufacturing the ultrasonic probe. And

[0007]

DISCLOSURE OF THE INVENTION According to the present invention, a backing material with an auxiliary plate formed by fixing unit hard auxiliary plates arranged two-dimensionally to the surface of a backing material, and a tip penetrating the backing material with the auxiliary plate. A plurality of signal lines whose surfaces are exposed on the surface of the unit hard auxiliary plate and each of which is electrically independent, and the plate surfaces are parallel to each other, and a plurality of plate-shaped signal derivation bodies, and the surface of the hard auxiliary plate The basic solution means is that the piezoelectric element is fixed to the signal line with a conductive adhesive and electrically connected to the signal line.

According to the present invention, the unit hard auxiliary plate is fixed to the surface of the backing material, and the signal lead-out body and the piezoelectric element exposed on the surface of the hard auxiliary plate are fixed. Therefore, the piezoelectric element and the backing material are directly conductive. It is not joined by a conductive adhesive.

[0009]

1 to 3 are views of a 1.5D probe for explaining an embodiment of the present invention. FIG. 1 is a perspective view of an ultrasonic probe, FIG. 2 is a partially cutaway front sectional view, and FIG. 3 is a side sectional view. It should be noted that the same parts as those of the previous conventional example are given the same numbers to simplify the description.

The 1.5D probe is a backing material 9 with an auxiliary plate.
And a plurality of signal derivation bodies 10 and the piezoelectric elements 1 arranged in the long axis direction. The backing material 9 with an auxiliary plate is formed by fixing an insulating unit hard auxiliary plate 11 in a two-dimensional direction on the surface of the backing material 2 with an adhesive agent (not shown). Each of the plurality of signal derivation bodies 10 is formed of a flat printed circuit board 14 having a large number of electrically independent signal lines 12 on a board 13. One end side of each printed circuit board 14 is embedded in the backing material 9 with an auxiliary plate with their plate surfaces parallel to each other. Then, the tip surface on one end side is provided with the unit hard auxiliary plate 11
Exposed on the surface of.

The piezoelectric element 1 is composed of three piezoelectric elements divided in the short axis direction and has electrodes on both main surfaces. Then, it is fixed on the unit hard auxiliary plate 11 by a conductive adhesive and electrically connected to the signal line 13 of the printed board 14. Then, in this embodiment, one main surface of each piezoelectric element 1 (abc) fixed to the unit hard auxiliary plate 11 is
A linear electrodeless portion 15 is provided. In addition, each piezoelectric element 1, the piezoelectric element 1 (abc), and the unit hard auxiliary plate 1
The space 1 is divided by a cut 16 that reaches the backing material 2.

With this structure, each piezoelectric element 1 (abc) has a unitary hard auxiliary plate 11 and a conductive adhesive 8
The adhesive strength is improved, and the adhesive strength is increased as compared with the case where the rubber-based backing material 2 is directly fixed without mechanical deformation due to impact. In this embodiment, the electrodeless portion 15 is provided on one electrode of each piezoelectric element 1 (abc) and fixed to the conductive adhesive 8. Therefore, the bonding strength can be further increased.

FIG. 4 to FIG. 9 are process drawings for explaining a method for manufacturing a 1.5D probe. The ultrasonic probe includes a piezoelectric plate 7, a backing material 9 with an auxiliary plate, and a plurality of signal derivation bodies 10 (see FIG. 1 above). The piezoelectric plate 7 has electrodes 6 (ab) on both main surfaces, and in this example, linear electrodeless portions 15 are formed vertically and horizontally on one main surface 6b (FIG. 4). As shown in FIGS. 5 and 6, the backing material 9 with an auxiliary plate is formed by fixing the backing material 2 and the hard auxiliary plate 11A with an insulative adhesive agent not shown.

The plurality of signal derivation bodies 10 are the above-mentioned printed boards 14 having signal lines on the boards. Then, one end side is embedded in the vertical direction with respect to the backing material 9 with the auxiliary plate. The tip portion on the one end side penetrates the backing material 2 and is inserted into the groove 17 of the hard auxiliary plate 11A to be covered in this example. The groove 7 is wider than the thickness of the printed board 14, and the gap is filled with, for example, an adhesive at the time of fixing.

In such a device, first, the front surface of the printed board 14 is exposed by polishing the surface of the backing material 9 with an auxiliary plate (hard auxiliary plate 11). Then, one main surface 6 of the piezoelectric plate 7 having the electrodes 6 (ab) on both main surfaces
b is fixed to the surface of the hard auxiliary plate 11 by the conductive adhesive 8 (FIG. 7).

Next, cut lines 16 are formed between the piezoelectric plate 7 and the backing material 2 between the plurality of signal lines 13 of the printed circuit board 14 to cut the piezoelectric plate 7 and the hard auxiliary plate 11 in the longitudinal direction. , Each piezoelectric element 1 is divided. FIG. 8 is a plan view in which the piezoelectric plate 7 is omitted, and a section between arrows AA ′ in FIG. 8 is cut. Then, similarly, the printed circuit boards 14 are cut in the minor axis direction so that each piezoelectric element 1 is separated into three piezoelectric elements 1.
It is divided into (abc) (between BB 'in FIG. 8).

According to such a manufacturing method, the electrode-free portion 1 having the unit hard auxiliary plate 11A on the backing material 2 and fixed to the unit hard auxiliary plate 11A with the conductive adhesive 8 is used.
Piezoelectric elements 1 composed of three piezoelectric elements 1 (abc) having 5 are arranged in the longitudinal direction to obtain a 1.5D probe (Fig. 1 before) in which electrodes are individually led out from each piezoelectric element. .

[0018]

[Other Matters] In the above embodiment, the electrodeless portion 15 is provided to further increase the bonding strength between the piezoelectric plate 7 and the conductive adhesive 8. However, basically, the hard auxiliary plate 11 increases the bonding strength. Therefore, in the present invention, the electrodeless portion 1 is not always required.
You don't need 5. In addition, the electrodeless portion 1 in the embodiment
5 has a width of 1/100 or less with respect to the size (length × width) (about 3 × 0.6 mm or more) of the piezoelectric element 1 (ac), so that the influence on the piezoelectric action is extremely small and substantially. Can be ignored.

Further, the piezoelectric element 1 is divided into three piezoelectric elements, but each piezoelectric element 1 (abc) is further provided with a groove 18 of 70% or more to be divided into a plurality of, for example, four, which are the width w. The ratio w / t of the thickness t is about 0.4 to 0.6
Good vibration characteristics may be obtained as
Figure). In this case, if the electrodeless portion 15 is set to the position of the groove 18, the piezoelectric effect of the electrodeless portion 15 is completely eliminated.

Further, the backing material 9 with the auxiliary plate is formed from the backing material 2 and the hard auxiliary plate 11 provided with the groove 17 into which the tip side of the signal lead-out body 10 (printed circuit board 14) is inserted. For example, an epoxy resin or the like may be applied and cured on the surface of the backing material 2 from which the tip of the printed board protrudes.

Further, the piezoelectric elements 1 arranged in the long axis direction are
The 1.5D probe which is divided into two piezoelectric elements and switches the opening area in the minor axis direction has been described as an example. However, the minor axis direction may be divided into three or more pieces. Can be basically applied to an ultrasonic probe in which two are arranged in a two-dimensional direction. Therefore, it is needless to say that it can be applied to a so-called matrix probe that electronically operates in the major axis and minor axis directions to obtain an image.

The electrode lead-out body 10 is a printed circuit board 14
However, as in the conventional example, it may be formed only from a signal line made of a thin metal plate, or may be formed from a flexible printed board (not shown). And the substrate 12
The signal line 13 may be subjected to, for example, solder plating to increase its thickness to enhance the electrical connection strength with the tip surface. Further, although the signal lines 13 are individually independent, a connecting portion may be provided and commonly connected as in the conventional example, and the connecting portion may be cut at the same time when the piezoelectric plate 7 is cut.

The present invention can be variously modified as described above, and in short, the backing material 2 and the piezoelectric element 1 (ab) are essential.
In the technical scope of the present invention, the hard auxiliary plate 11 is interposed and the piezoelectric element 1 (abc) is fixed to the piezoelectric element 1 (abc) by the conductive adhesive 8 without directly joining with c). Basically belongs to.

[0024]

According to the present invention, a backing material with an auxiliary plate formed by fixing unit hard auxiliary plates arranged in a two-dimensional direction to the surface of a backing material, and a tip surface penetrating the backing material with the auxiliary plate is the unit described above. A plurality of signal conductors, which are exposed on the surface of the hard auxiliary plate and each of which is electrically independent of each other, and the plate surfaces of which are parallel to each other, and a plurality of signal derivation members in a flat plate shape, and conductive adhesion to the surface of the hard auxiliary plate. Since it is composed of a piezoelectric element that is fixed by an agent and electrically connected to the signal line, an ultrasonic probe that maintains the bonding strength between the backing material and the piezoelectric element while maintaining the convenience of the conductive adhesive and The manufacturing method can be provided.

[Brief description of drawings]

FIG. 1 is a diagram of a 1.5D probe for explaining an embodiment of the present invention.

FIG. 2 is a front sectional view in which a part of a 1.5D probe for explaining the embodiment of the present invention is cut away.

FIG. 3 is a side sectional view of a 1.5D probe for explaining an embodiment of the present invention.

FIG. 4 is a plan view of a piezoelectric plate illustrating an embodiment of the present invention.

FIG. 5 is an exploded perspective view of a backing material with an auxiliary plate for explaining the manufacturing method of the present invention.

FIG. 6 is a cross-sectional view of a backing material with an auxiliary plate for explaining the manufacturing method of the present invention.

FIG. 7 is a cross-sectional view of a backing material with an auxiliary plate for explaining the manufacturing method of the present invention.

FIG. 8 is a plan view showing a cutting direction of the piezoelectric plate for explaining the manufacturing method of the present invention.

FIG. 9 is a partial view of a 1.5D probe for explaining another embodiment of the present invention.

FIG. 10 is a plan view of a 1.5D probe for explaining a conventional example.

FIG. 11 is a diagram of a backing material of a 1.5D probe for explaining a conventional example.

FIG. 12 is an exploded view of a 1.5D probe in a manufacturing process for explaining a conventional example.

13A and 13B are diagrams of a 1.5D probe for explaining a conventional example, where FIG. 13A is a front view and FIG. 13A is a side sectional view.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 piezoelectric element, 2 backing material, 3 and 13 signal lines, 4 thin metal plates, 5 connecting parts, 6 electrodes, 7 piezoelectric plates,
8 conductive adhesive, 9 backing material with auxiliary plate, 10
Signal derivation body, 11 unit hard auxiliary plate, 12 substrate, 14
Printed circuit board, 15 electrodeless part, 16 cut lines, 1
7, 18 grooves,

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Claims (3)

(57) [Claims] 1. Piezoelectric elements having electrodes on both main surfaces are two-dimensionally arranged on a backing material, and the electrodes are individually led out from electrodes on one main surface of the piezoelectric element facing the backing material. In the ultrasonic probe, a backing material with an auxiliary plate in which unit hard auxiliary plates are arranged and fixed to the surface of the backing material in a two-dimensional direction, and a tip surface penetrating the backing material with the auxiliary plate has a front surface of the unit hard auxiliary plate. A plurality of signal lead-out bodies which are exposed to the surface and each of which has a plurality of electrically independent signal lines and whose plate surfaces are parallel to each other and are formed into a flat plate, and which are fixed to the surface of the hard auxiliary plate with a conductive adhesive An ultrasonic probe comprising a piezoelectric element electrically connected to a signal line. 2. The piezoelectric plate according to claim 1, wherein a plurality of linear electrodeless portions are formed on at least one of two-dimensional directions on one main surface to which the piezoelectric plate is fixed to expose the substrate of the piezoelectric plate. An ultrasonic probe characterized by that. 3. A piezoelectric plate having electrodes on both main surfaces is provided on a backing material, and a cut reaching from the piezoelectric plate to the backing material is provided to cut the piezoelectric plate vertically and horizontally. In a method for manufacturing an ultrasonic probe, which is divided into a number of piezoelectric elements arranged in a dimensional direction, each electrode is individually derived from an electrode on one main surface of the piezoelectric element facing the backing material, A backing material with an auxiliary plate having a hard auxiliary plate fixed to the surface of the backing material,
A plurality of signal derivation members which are embedded in the backing material with the auxiliary plate and have one end side covered with the hard auxiliary plate and each of which has a plurality of electrically independent signal lines and whose plate surfaces are parallel to each other and which are plate-shaped. And polishing the surface of the hard auxiliary plate to expose the tip surface of the signal lead-out body, fixing the piezoelectric plate with a conductive adhesive on the hard auxiliary plate, and connecting the plurality of signal lines. And a cut that reaches the backing material from above the piezoelectric plate is provided between the plurality of signal derivation bodies to vertically and horizontally cut the piezoelectric plate and the hard auxiliary plate, and the piezoelectric plates are arranged in a two-dimensional direction. A method for manufacturing an ultrasonic probe, which is divided into a large number of piezoelectric elements, and the electrodes are individually led out from the electrodes on one main surface of the piezoelectric element facing the backing material by the signal lead-out body.