JPH01278200A - Arranging type ultrasonic probe - Google Patents

Abstract

PURPOSE:To improve workability and to surely perform an operation by positioning the common line part of a flexible substrate inside the one end side of a rectangular piezoelectric plate, and dividing and forming it after providing a space between the one end part of the rectangular piezoelectric plate and the flexible substrate and connecting them. CONSTITUTION:The common line part 16 provided at the confronting piece part of a hollow part 4 of the flexible substrate 2 is positioned inside the one end side of the rectangular piezoelectric plate 1, and the space 10 consisting of the thickness of a conductive path 17 is provided between the one end part of the rectangular piezoelectric plate 1 and the flexible substrate 2, then, they are connected. After that, the flexible substrate 2 is bent to both side planes of a packing material 11, and the conductive path from the piezoelectric plate 1 to the flexible substrate 2 is cut sequentially, thereby, an individual piezoelectric piece 12 set independently electrically and connected to the conductive path can be obtained. In such a way, it is possible to obtain an arranging type probe with superior workability and capable of performing the operation surely.

Description

[Detailed description of the invention] (Industrial field of application) The field of the present invention is an array-type ultrasonic probe (hereinafter referred to as an array-type probe) using a flexible substrate. This invention relates to an array type probe that prevents malfunctions.

(Background of the Invention) An array type probe is formed by arranging a plurality of piezoelectric pieces, and is useful as an ultrasonic transmission/reception wave source in, for example, medical, mining and industrial diagnostic equipment and flaw detection equipment. For example, delayed pulses are sequentially applied to a plurality of piezoelectric pieces to perform so-called sector scanning, transmitting and receiving ultrasonic waves in a fan shape, and diagnosing a diseased area. In recent years, due to miniaturization and segmentation, the electrodes of piezoelectric pieces are led out using flexible substrates.

(Conventional technology) FIG. 3 is a diagram illustrating this type of array type probe.

Array type probes are first made of lead zirconate titanate (
A rectangular piezoelectric plate 1 made of PZT (hereinafter referred to as PZT) is attached to a flexible substrate 2. Note that excitation electrodes 3n and 3b are formed on both main surfaces of the piezoelectric plate 1 to excite vibration in the thickness direction. The flexible substrate 2 is formed by forming a conductive path 6 on a resin base 5 made of, for example, polyimide and having a hollow portion 4, and further laminating a resin cover (not shown) thereon.

The conductive paths 6 extend from opposite sides of the hollow portion 4 in a staggered manner at equal intervals j7. The surface of the conductive path 6 is exposed at a constant width W from the end of the wood base 5 to form a bonding surface 9.

Then, both ends of the piezoelectric plate 1 in the transverse direction are bonded and attached to the bonding surface 9 of the flexible substrate 2 (signal line) by, for example, soldering, as shown in FIG. 3(a).

Note that the piezoelectric plate 1 and the flexible substrate 2 are bonded together to form a substrate assembly 10.

Next, as shown in FIG. 3(b), 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 onto both sides of the backing material 11, and the conductive paths 6 are sequentially cut from the top of the piezoelectric plate 1. Then, as shown in FIG. 3(C), individual piezoelectric pieces 12 are electrically independently connected to each conductive path 6 to form an array type probe. Note that normally, before and after cutting the substrate assembly 10, an acoustic matching layer (not shown) is formed 17 on the free surface side of the piezoelectric plate 1 (piezoelectric piece 12), and this surface is used as a wave surface for transmitting and receiving ultrasonic waves.

(Problems with the Prior Art) However, in the above ultrasonic probe, the hollow portion 4 of the flexible substrate 2 is usually formed by pressing, for example, a flexible substrate formed by making the exposed end portion of each conductive path 6 longer. It is formed by simultaneously cutting a part of the tip side of each conductive path by punching, etc.

For this reason, an external force is applied to the cut surface of the exposed portion of each Ti guiding path 6, and the cut surface does not necessarily become straight as before cutting, but is bent in a predetermined direction as shown in FIG. 4.

Therefore, in such a device, when the piezoelectric plates 1 and 7 flexible substrate 2 are attached and then cut between the 6 ri-way paths to obtain individual piezoelectric pieces 12, each conductor 1 is cut off between the 6 ri-way paths. IS path 6 and piezoelectric piece 1
It does not match the joint surface of No. 2, and an unjoined portion (misalignment) occurs.

As a result, there was a problem of weakening electrical and mechanical bonding strength and deteriorating impact resistance.

In order to solve this problem, for example, a common line 13 of 11151w is provided on the opposite side of the hollow part 4, and this common line 1
A flexible board 2 with a signal line extended from 3 is used (
There is one formed by 7. That is, the hollow portion 4 is formed by cutting a flexible substrate on which a common line (not shown) having a width larger than the width W is formed in advance together with a part of the common line. Therefore, when forming the hollow portion 4, no external force is directly applied to the conductive path 6, so that its straight shape is maintained. As a result, in such a device, even if both ends of the piezoelectric plate 1 and the end of the common line 13 are aligned and joined, and then both are cut integrally between the conductive paths 6, the piezoelectric piece and the conductive The electrical and mechanical bonding strength with the path 6 can be maintained reliably.

However, in this case, when forming the substrate assembly 10, a conductive bonding material such as solder is uniformly applied between the electrode 3b of the piezoelectric plate 1 and the bonding surface 9, and both are electrically connected.
The connection must be mechanically secure. That is, even if the substrate assembly 10 is divided finely into thin wire-shaped piezoelectric pieces 12, the electrical and mechanical bond between the two is maintained.

Normally, this is achieved by applying a slightly larger amount of bonding material 17. Therefore, as shown in FIG. 6, the bonding material 14 protrudes from between the piezoelectric plate 1 and the bonding surface in the form of granular excess, and this protrudes onto the t'WIIFJ cover 15. In such a case, the operator is forced to manually detect and remove the surplus 14', which reduces productivity. If a part of this surplus 14' that is particularly likely to come loose is left unattended, it will be scattered by impact or the like, causing a short circuit between the electrodes 3 of each piezoelectric piece 12, for example.

Furthermore, if the substrate assembly 10 is cut into one piece, a crack or the like will be generated in the portion of the common line 13 that protrudes from one end of the piezoelectric plate 1. 17. This Paris etc. have a direct or indirect adverse effect and deteriorate the insulation between the conductive paths 6. In addition, it also becomes a source of metal debris, and as described above, there is a problem in that short-circuiting occurs between the electrodes 3, etc., resulting in malfunction.

(Objective of the Invention) The present invention provides an array type probe that has good workability, maintains the electrical and mechanical bonding strength between the flexible substrate and the piezoelectric piece, increases #4 impact resistance, and can operate reliably. The purpose is to provide

(Solution Means) In the present invention, the common line provided in the opposing piece of the hollow part of the flexible substrate is located inside one end of the rectangular piezoelectric plate, and between the one end of the rectangular piezoelectric plate and the flexible substrate. The solution is to connect the two with a gap and then form them separately. An embodiment of the present invention will be described below.

(Embodiment) FIG. 1 is a diagram of an ultrasonic probe illustrating an embodiment of the present invention. Note that the same parts as those in the previous embodiment drawings are given the same numbers for explanation.

First, the array type probe has electric i3n,
A piezoelectric plate 1 made of PZT having a structure 3b formed thereon is placed in a hollow part 4.
It is attached to the flexible substrate 2 formed with . On the fM resin base 5 of the flexible substrate 2, a common line 16 extending along opposite sides of the hollow portion and a plurality of conductive paths 17 extending from the common line 16 in a staggered manner at equal intervals are formed. common track 1
6 is made so that its width [I is smaller than the above-mentioned width W. Then, the surfaces of the common line 1G and the extending start end of the conductive path 17 are exposed to form a joint surface with a width [1' indicated by double diagonal lines. 18.

There are four 11M not shown on the resin base 5 other than the joint surface 18.
Make M layers of cover. That is, between the common line 16 and the starting end of each conductive path 17, a void 19 should be created due to the thickness of the conductive path 17. Then, both ends of one main surface of the piezoelectric plate 1 are aligned with the bonding surface 18 and attached using a bonding material. That is, the common line 16 is located inside the end of the piezoelectric plate 1, and connects both end sides of the piezoelectric plate 1 and the substrate resin body 5 in the empty space.
The substrate assembly 20 is formed with a gap between them [FIG. 1 (all).

Next, as described above, the substrate assembly 20 is attached to the backing material 11.
The flexible substrate 2 is bent onto both sides of the backing material 11, and the conductive paths of the flexible substrate 2 are sequentially cut from the top of the piezoelectric plate 1.

Then, each piezoelectric piece 12 is electrically independently connected to a conductive path to form an array type probe.
.

In the array type probe having such a configuration, when the piezoelectric plate 1 is attached to the bonding surface 18, the excess portion 14' of the bonding material 14 is inserted into the stepped cavity 19 as shown in FIG. It becomes easier to leak out. Then, the amount of protrusion from the end of the piezoelectric plate 1 onto the cell cover 21 is reduced.

Therefore, in such a case, the work of removing the surplus portion 14 should be simplified to improve work efficiency. The surplus portion 14' may be fixed within the cavity 19, thereby preventing it from becoming separated due to impact or the like. Further, since the common line 17 is located and fixed inside the piezoelectric plate, generation of particles (metal chips) etc. can be suppressed to a minimum even if the substrate assembly 10 is cut integrally. Therefore,
It is possible to prevent short circuits between the electrodes 3 and the conductive path 17 including the cut common n-line due to excess solder or metal scraps, improve insulation, and ensure reliable operation.

(Other Matters) In the above embodiment, the conductive paths are extended in a staggered manner from the common line 16 provided on the opposite side of the hollow part, but the present invention can extend from only one common line, for example. The conductor WsFpI as a signal line can be extended and the other common line can be used for a long distance as a ground potential line. In short, the present invention can be applied to the case where common lines are provided on opposite sides of a hollow portion, piezoelectric plates are attached, and the latter piezoelectric plates are divided to form an array type probe.

(Effects of the Invention) The present invention positions the common line portion of the flexible substrate inside one end of the rectangular piezoelectric plate, and connects the two by providing a gap between the one end of the rectangular piezoelectric plate and the flexible substrate. Since the probe is divided and formed after the process, it is possible to provide an array type probe that has good workability and operates reliably.

[Brief explanation of the drawing]

FIGS. 1(fl) and 1(b) are process diagrams for explaining the array type probe of the present invention, and FIG. 1(a) is an assembly diagram of the substrate assembly, and FIG.
1)) is a partial diagram of an array type probe. FIG. 2 is a sectional view taken along line AA' of the substrate assembly shown in FIG. 1(a). FIGS. 3(a), 3(b), and 3(c) are process diagrams of an ultrasonic probe explaining a conventional example, and FIG. 3(a) is an assembly diagram of a substrate assembly;
Figure (b) is a diagram with the board assembly attached to the backing material.
FIG. 3(c) is a partial diagram of the array type probe. FIG. 4 is a plan view of a flexible substrate illustrating the drawbacks of the conventional example (FIG. 3). FIG. 5 is an assembly diagram of a substrate assembly explaining another conventional example, and FIG. 6 is a T'(-B' sectional view) of the same substrate assembly. 1 Piezoelectric plate, 2 Flexible substrate, 3 Electrode, 4 Hollow part, 5-m4n; 3 base, 6,17-conducting M llr
,,9.18 Bonding surface, 10 Substrate bonded body, 1 Dopa, Socking material, 13.16・Common line, 14・Joining 4.1
5. Tree vesicle cover, 19. Vacant part.

Claims (2)

[Claims] (1) Common conductive path portions provided on opposite sides of the hollow portion of the flexible substrate are connected to both ends of one main surface of a rectangular piezoelectric plate with electrodes formed on both main surfaces using a bonding material,
In the array type ultrasonic probe formed by integrally cutting the rectangular piezoelectric plate and the common conductive path portion between the signal lines extending from the common path portion, 1. An array-type ultrasonic probe characterized in that a rectangular piezoelectric plate is attached inside one end of the piezoelectric plate, and a gap is provided between both end sides of the piezoelectric plate and a flexible substrate. (2) The array type ultrasonic probe according to claim 1, wherein signal lines extend in a staggered manner from the opposing common line portions.