JP2589541B2 - Array type ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention is applied to an array type ultrasonic probe using a flexible substrate (hereinafter, referred to as an array type probe), and has particularly good workability. The present invention relates to an array-type probe in which a malfunction is prevented.

(Background of the Invention) An array-type probe is formed by arranging a plurality of piezoelectric pieces, and is useful as a transmitting / receiving source of ultrasonic waves in, for example, a diagnostic device for medical use, mining and industrial use, and a flaw detector. For example, a so-called sector scan is performed by sequentially applying a delay pulse to a plurality of piezoelectric pieces to transmit and receive ultrasonic waves in a fan shape, thereby diagnosing a diseased part. In recent years, due to miniaturization, subdivision, and the like, the electrodes of the piezoelectric pieces are led out using a flexible substrate.

(Prior Art) FIG. 3 is a diagram illustrating this type of array-type probe.

In the array type probe, first, a piezoelectric plate 1 made of, for example, lead zirconate titanate (hereinafter, referred to as PZT) is attached to a flexible substrate 2. Excitation electrodes 3a and 3b that excite vibration in the thickness direction are formed on both main surfaces of the piezoelectric plate 1.
The flexible substrate 2 has a conductive path 5 formed on a resin base 4 made of, for example, polyimide, and further has a resin cover 6 formed thereon.
Are laminated. The conductive path 5 includes a common line section 7 and a plurality of line sections 8 extending at equal intervals from the common line section 7. The width of the common line portion 7 is w, and a surface thereof is exposed at a constant width w ′ from an end of the resin base 4 to form a bonding surface 9. In addition, the common line section 7
Is made of copper foil or the like.

Then, one end in the short direction of the piezoelectric plate 1 is attached to the joining surface 9 of the flexible substrate 2 by, for example, soldering or the like, as shown in FIG. 3 (a). In addition, what bonded the piezoelectric plate 1 and the flexible substrate 2 is referred to as a substrate bonded body 10.

Next, the flexible substrate side of the substrate assembly 10 is attached onto the backing material 11. The backing material 11 is made of, for example, insulating rubber. The flexible substrate 2 is bent to the side surface of the backing material 11, and the portions between the line portions 8 are sequentially cut from above the piezoelectric plate 1. Then, the individual piezoelectric pieces 12 electrically and independently connected to the respective line portions 8 are obtained and used as an array-type probe.
Figure (b) ". Normally, an acoustic matching layer (not shown) is formed on the free surface side of the piezoelectric plate 1 (voltage piece 12) before and after the cutting of the substrate assembly 10, and this surface is used as an ultrasonic wave transmitting / receiving surface.

(Problems of the Related Art) However, such an ultrasonic probe uses a conductive bonding material such as solder when forming the substrate bonded body 10. Then, the bonding material must be applied uniformly between the electrode 3b of the piezoelectric plate 1 and the bonding surface 9, and the two must be reliably connected electrically and mechanically. That is, after the substrate bonded body 10 is formed, it is finely divided into the thin line-shaped piezoelectric pieces 12, and if there is a blank portion, electrical and mechanical connection is impaired. For this reason, the bonding material is usually applied slightly larger. As a result, as shown in FIG. 4, the bonding material 13 protrudes from between the piezoelectric plate 1 and the bonding portion, and the surplus 14 becomes granular and protrudes onto the resin cover 6. In such a case, it is necessary to manually detect and remove the surplus 14. When the surplus part 14 which is particularly easy to separate is notified, the surplus part 14 is separated by an impact or the like, and short-circuits between the electrodes 3 of each piezoelectric piece 12 and between the common line portions 7 after cutting.

Further, when the substrate joined body 10 is integrally cut, burrs and the like are generated at a portion of the common line portion 7 protruding from one end of the piezoelectric plate 1. The burrs and the like have an adverse effect directly or indirectly, and deteriorate the insulation between the common line portions 7. In addition, there is also a problem that it becomes a generation source of metal dust and short-circuits between the electrodes 3 and between the cut common line portions 7 to cause an operation failure as described above.

(Object of the Invention) An object of the present invention is to provide an ultrasonic probe that operates reliably with good workability.

(Solution) According to the present invention, a common line portion of a flexible substrate is positioned inside one end of a rectangular piezoelectric plate, and a gap is provided between one end of the rectangular piezoelectric plate and the flexible substrate to connect them. Later, the divided formation is a solution. Hereinafter, an embodiment of the present invention will be described.

(Embodiment) FIG. 1 is a diagram of an ultrasonic probe for explaining an embodiment of the present invention. The same parts as those in the previous embodiment are denoted by the same reference numerals and described.

As described above, the array-type probe firstly attaches a piezoelectric plate 1 made of PZT having electrodes 3 formed on both main surfaces to a flexible substrate 2.
Attach to On the resin substrate 4 of the flexible substrate 2, a common line portion 7 and a plurality of line portions 8 extending at equal intervals from the common line portion 7 extend to form a conductive path 5. The common line section 7 has a width d
Is smaller than the width w described above. Then, the surface within the width d ′ larger than the width d is exposed from the end of the resin base 4,
The resin cover 6 is laminated on the other surface. That is, the common line portion 7 and the extending start end 15 of each line portion 8 are used as the joining surface 16, and a part of the resin base 4 is exposed as the empty space 17.
Then, one end of one main surface of the piezoelectric plate 1 is aligned with the bonding surface 16 and attached by a bonding material. That is, the common line section 7
Is located inside the end of the piezoelectric plate 1, and the void 17 is
1A is formed as a gap between one end of the flexible substrate 2 and the flexible substrate 2. FIG.

Next, in the same manner as described above, the substrate assembly 10 is attached to the backing material 11, the flexible substrate 2 is bent to the side of the backing material 11, and the conductive paths of the flexible substrate are sequentially cut from above the piezoelectric plate. Then, individual piezoelectric pieces electrically independently connected to the conductive paths are obtained to form an arrayed wave probe (FIG. 1B).

In the acoustic probe having such a configuration, when the piezoelectric plate 1 is attached to the bonding surface 16, the surplus portion 14 of the bonding material 13 flows into the gap 17 having a step as shown in FIG. Easier to do. Then, the amount of protrusion from the end of the piezoelectric plate 1 onto the resin cover 6 is reduced. Therefore, such a structure simplifies the work of removing the surplus 14 and enhances the workability. The surplus portion 14 is sometimes fixed in the gap portion 17 to prevent separation due to impact or the like.

Further, since the common line portion 7 is positioned and fixed inside the piezoelectric plate 1, even if the substrate joined body 10 is integrally cut, the generation of burrs and the like is suppressed to a small extent.

Therefore, short-circuiting between the electrodes of the piezoelectric piece and between the common line portions after cutting, etc. can be prevented, the insulation properties can be improved, and a reliable operation can be performed.

(Other Matters) In the prior art of the present invention, as shown in FIG. 5, for example, as shown in FIG. There is one in which the piezoelectric plate 1 is exposed and one end side is attached. In this case, a surplus portion of the bonding material (not shown) flows out into the gap between the lines. Also,
Since the common line portion is not provided, no burrs are generated, and the same effect as in the present invention can be expected. However, the line portion 18 divided in advance has problems in positioning, cutting accuracy, and the like when forming the substrate joined body or dividing and cutting. Therefore, it is fundamentally different from the present invention.

Also, in the present invention, a description has been given of the case where the flexible substrate is attached only to one end of the piezoelectric plate, but for example, the flexible substrate is attached to both ends of the piezoelectric plate as in the case where the electrodes are led out in a staggered manner. Needless to say, this can also be applied.

(Effects of the Invention) According to the present invention, the common line portion of the flexible substrate is positioned inside one end of the rectangular piezoelectric plate, and a gap is provided between the one end of the rectangular piezoelectric plate and the flexible substrate to connect them. After that, it is possible to provide an ultrasonic probe that operates reliably with good workability.

[Brief description of the drawings]

1 (a) and 1 (b) are views for explaining an ultrasonic probe according to the present invention, wherein FIG. 1 (a) is an assembly partial view of a piezoelectric plate and a flexible substrate, and FIG. FIG. Second
The figure is a sectional view taken along the line AA 'of the bonded substrate shown in FIG. 1 (a). FIGS. 3 (a) and 3 (b) are views of an ultrasonic probe for explaining a conventional example, wherein FIG. 3 (a) is an assembly partial view of a piezoelectric plate and a flexible substrate, and FIG. FIG. 4th
The figure is a cross-sectional view of the bonded substrate shown in FIG. FIG. 5 is an ultrasonic probe diagram for explaining another conventional example. 1 ... Piezoelectric plate, 2 ... Flexible board, 3 ... Electrode,
4 ... resin base, 5 ... conductive path, 6 ... resin cover, 7
... common line section, 8, 18 ... line section, 9, 16 ... joining surface, 10 ... substrate joined body, 11 ... backing material, 12 ... piezoelectric piece, 13 ... joining material, 14 ... Excess, 15 ... Extending start end, 17 ... Vacancy.

Claims (1)

(57) [Claims] A common conductive path portion of a flexible substrate is attached to one end of one side main surface of a rectangular piezoelectric plate having electrodes formed on both main surfaces by a bonding material, and then extends from the common conductive path portion. In the array type ultrasonic probe formed by integrally cutting the rectangular piezoelectric plate and the common conductive path portion in a portion between the respective lines, the common line portion is located at one end of the rectangular piezoelectric plate. An array type ultrasonic probe which is attached inside and is formed with a gap provided between one end of a piezoelectric plate and a flexible substrate.