JP2945978B2 - Array type ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an array type ultrasonic probe (hereinafter, referred to as an array type probe), and particularly to an array type probe using a composite piezoelectric plate. About the tentacles.

(Background of the Invention) An array-type probe is useful as a transmitting and receiving unit of an ultrasonic wave in, for example, an ultrasonic diagnostic apparatus for medical use. In recent years, in order to obtain broadband characteristics, use of a composite piezoelectric plate material in which a piezoelectric material is filled with a polymer resin has attracted attention.

(Prior Art) FIG. 3 is a view for explaining an array-type probe using a composite piezoelectric plate of this type.

The composite piezoelectric plate 1 is made of a composite material of a micro piezoelectric piece 2 such as lead zirconate titanate (commonly called PZT) and a polymer resin 3. For example, a flat piezoelectric plate (not shown) is fixed on the base 4 and then cut vertically and horizontally to form grooves, thereby forming a large number of micro piezoelectric pieces 2. Then, each groove and its outer periphery are filled with the polymer resin 3 and the micro piezoelectric pieces 3 are joined together (FIG. 3A).

Next, this is detached from the base 4 to form the rows of opposed electrodes 5 on both main surfaces. Then, such a composite piezoelectric plate 1 is mounted on the backing material 6, and the opposing portions of the electrodes are used as vibrating portions. However, a flexible printed board (hereinafter referred to as a flexible board) 7 is provided on the backing material 6.
Is fixed at one end. Then, the respective conductive paths 8 exposed at one end side and the respective row electrodes are aligned and electrically and mechanically connected as shown in FIG. 3 (b). Alternatively, after removing from the base 4, the electrodes 5 are formed on the entire surfaces of both main surfaces, and attached on the backing 6 material. Then, a cut 9 reaching the backing material 6 from above the electrode is provided to divide the common line to be each conductive path 8 of the flexible substrate 7 together with the composite piezoelectric plate 1 to divide the common line as shown in FIG. Was composed.

Therefore, in such a structure, the composite piezoelectric plate 1 has a wider frequency characteristic due to the presence of the polymer resin than the case where only the piezoelectric plate is used. Further, since the acoustic impedance is reduced, the difference is reduced when the object to be detected is, for example, a living body, and the acoustic matching layer can be formed as a single layer.

(Problems of the prior art) However, in the array-type probe having the above configuration, when the row-shaped electrodes 5 are formed and configured, the flexible substrate 7 is used.
Must be attached to the backing material 6 so as to coincide with the respective conductive paths 8, which makes positioning difficult and reduces workability. Further, when the electrode 5 is formed on the entire surface and divided, there is a problem in that the number of cutting steps including the time of forming the composite piezoelectric plate 1 is large and productivity is poor.

(Object of the Invention) An object of the present invention is to provide an array-type probe using a composite piezoelectric plate while maintaining good productivity and characteristics.

According to the present invention, a composite piezoelectric plate is formed by filling a bonding material between bar-shaped diaphragms arranged in the x direction of coordinates (x, y), and the x direction of the composite piezoelectric plate and a flexible printed circuit board are formed. The composite piezoelectric plate is fixed on a conductive plate connected to one end of the flexible substrate with a conductive adhesive so that the extending direction of the common line provided on one end side of the composite piezoelectric plate is aligned with the conductive line. And a common line is cut in the y direction to form a plurality of rod-shaped composite plates, and a common electrode is provided on a surface of the rod-shaped composite plate. Hereinafter, an embodiment of the present invention will be described with reference to manufacturing steps.

(Embodiment) FIG. 1 is a process drawing of an ultrasonic probe for explaining an embodiment of the present invention. The same parts as those in the prior art are denoted by the same reference numerals, and description thereof will be simplified.

In this embodiment, first, a plate-shaped piezoelectric plate made of PZT is fixed on the base 4 and cut in the x-direction of the x and y coordinates to form the rod-shaped diaphragm 10. Note that electrodes 5 are provided on both main surfaces of the piezoelectric plate in advance.
Is given. Then, a bonding material such as a polymer resin 3 is filled between the rod-shaped vibration plates 10 and the outer periphery thereof to form a composite piezoelectric plate 11 (FIG. 1A).

Next, the composite piezoelectric plate 11 is fixed on the conductive plate 12 using a conductive adhesive 13. The conductive plate 12 is, for example, a copper foil 14 on a resin substrate 13.
Or by plating or the like. Then, this is fixed on the backing material 6 to which one end of the flexible substrate 7 is connected. However, a common line 17 is formed on one end side of the flexible 7, and the extending direction of the common line 17 matches the x direction of the composite piezoelectric plate (FIG. 1 (b)).

Next, a plurality of bar-shaped composite plates 16 are formed in the y direction by providing a cut 9 between the composite piezoelectric plate 11 and the conductive plate 12 to reach the backing material 6 from above the composite piezoelectric plate 11. At this time, the common line 17 of the flexible substrate 7 is divided and individually connected to the electrodes of each bar-shaped composite plate 16 to form each conductive path 8. Then, for example, a conductive adhesive 13 is applied to the surface of the rod-shaped composite plate 16 to commonly connect the electrodes 5 of the respective piezoelectric pieces in the y direction. An acoustic matching layer, an acoustic lens, and the like (not shown) are attached to the ultrasonic wave transmitting / receiving surface side.

In such a structure, since the conductive plate 12 and the common line 17 of the flexible 7 are connected and divided, it is not necessary to align the conductive paths 5 of the flexible substrate 7 and the electrodes of the bar-shaped composite plate 16 in advance. Further, since the composite piezoelectric plate 11 bonded only in the x direction is attached to the backing material 6 and then cut in the y direction, the number of cutting steps can be reduced as compared with the conventional example. Therefore, productivity can be improved after using the composite piezoelectric material. In addition, since the composite piezoelectric plate 11 is fixed to the conductive plate 12 by a conductive adhesive without being directly connected to the common line 17 of the flexible substrate 7 by soldering or the like, the composite piezoelectric plate 11 is heated and pressed during bonding. Characteristic deterioration, breakage, etc. can be prevented. In addition, the rod-shaped composite plate 16 and the backing material 6
Since the conductive material 12 is interposed between the backing material and the backing material 6 when the transmitting / receiving surface is pressed against the living body or the like, for example,
Distortion due to deformation of (usually rubber) or the like is prevented from being transmitted to the rod-shaped composite plate 16 to prevent breakage or the like.

(Other Matters) In the above embodiment, electrodes are formed on both main surfaces of the piezoelectric plate in advance. However, since a conductive adhesive is applied to both main surfaces of the piezoelectric plate, for example, This is not necessary as long as it has been subjected to polarization processing. Further, the conductive plate 12 is obtained by plating the resin substrate 14, for example, but may be any conductive material such as a metal. Further, when the composite piezoelectric plate 11 is cut in the y direction, a cut 9 reaching the backing material 7 is provided to form a rod-shaped composite plate 16 which is composited only in the x direction. For example, as shown in FIG. A groove 18 reaching the conductive material 12 is provided between the gap 9 and the conductive material 12 and the polymer resin 3 is filled.
May also be combined in the y direction. In this case, it goes without saying that a plurality of division grooves 18 may be provided, and the degree of division in the x and y directions is determined by the acoustic impedance and the band characteristics.
The cut 9 may be filled with a polymer resin. Further, the composite piezoelectric plate 11 is formed by cutting the piezoelectric plate in the x and y directions and filling the groove and its outer periphery with a binder, but the outer periphery may be free of the binder. Further, the conductive material 12 is fixed on the backing material, but may be fixed directly on a holding table (not shown).

(Effects of the Invention) The present invention forms a composite piezoelectric plate by filling a bonding material between rod-shaped diaphragms arranged in the x direction of coordinates (x, y), and forms a flexible print with the x direction of the composite piezoelectric plate. The extending direction of the common line provided on one end side of the substrate is matched, and the composite piezoelectric plate is fixed on a conductive plate connected to one end side of the flexible substrate with a conductive adhesive, and the composite piezoelectric plate is electrically conductive with the composite piezoelectric plate. The plate and the common line are cut in the y-direction to form a plurality of rod-shaped composite plates, and a common electrode is provided on the surface of the rod-shaped composite plate, so that a composite piezoelectric plate that maintains good productivity and characteristics can be used. An array type probe can be provided, and its practical effect is great.

[Brief description of the drawings]

1 (a) and 1 (b) are perspective views, and FIG. 1 (c) is a process diagram of an ultrasonic probe for explaining an embodiment of the present invention.
Is a partially broken front view. FIG. 2 is a partially cutaway front view of an ultrasonic probe illustrating another embodiment of the present invention. 3A and 3B are process diagrams of an ultrasonic probe for explaining a conventional example, wherein FIG. 3A is a perspective view, and FIGS. 3B and 3C are partially cutaway front views.

Claims (1)

(57) [Claims] 1. A composite piezoelectric plate is formed by filling a bonding material between bar-shaped diaphragms arranged in the x direction of coordinates (x, y), and the composite piezoelectric plate is formed in the x direction and one end of a flexible printed circuit board. The composite piezoelectric plate is fixed on a conductive plate connected to one end of a flexible substrate with a conductive adhesive, and the composite piezoelectric plate and the conductive plate are connected to the common line. Are cut in the y-direction to form a plurality of rod-shaped composite plates, and a common electrode is provided on the surface of the rod-shaped composite plate, thereby providing an array-type ultrasonic probe.