JP2001258880A - Ultrasonic probe manufacturing method - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for manufacturing an arrayed probe in which a tomographic image is improved to maintain the strength, and furthermore, the productivity is improved and the design range is expanded. In a method of manufacturing an ultrasonic probe in which a plurality of piezoelectric elements are arranged in a width direction on a backing material with a gap, and the gap is filled with a resin, the method includes the steps of: The manufacturing method is such that the gap is mechanically widened and the resin is filled. The means for mechanically expanding the gap is a method of pulling the backing material toward both ends. The means for mechanically expanding the gap is a method of bending the backing material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an array type (array type)
The manufacturing method of the ultrasonic probe (hereinafter referred to as an array type probe) is set as an industrial technical field, and particularly relates to an ultrasonic probe with an improved arrangement accuracy of piezoelectric elements.

[0002]

2. Description of the Related Art An ultrasonic probe is widely known as an ultrasonic transmitting / receiving section of a medical ultrasonic diagnostic apparatus. One of such devices is an array-type probe in which piezoelectric elements are arranged in the width direction and driven linearly or in a sector.

FIG. 4 is a cross-sectional view of an array type probe for explaining a conventional example. The array type transducer is
A plurality of strip-shaped piezoelectric elements 1 are arranged on the backing material 2 in the width direction. Excitation electrodes (not shown) are provided on both main surfaces of the piezoelectric element 1. An acoustic matching layer 3 (ab) having a two-layer structure for matching acoustic impedance with a detection target (a living body in this case) is provided on the transmitting / receiving wave surface side. The excitation electrode is led out to the outside by, for example, a flexible substrate (not shown).

In general, a piezoelectric plate (not shown) having electrodes on both main surfaces is fixed on a backing material 2, and a first layer (glass or ceramic) 3a of an acoustic matching layer is adhered. Further, the second layer (resin 4) 3b of the acoustic matching layer is formed by polishing or grinding after applying the resin, or by sticking.
Then, a cut reaching the backing material 2 is provided from above the second layer 3b of the acoustic matching layer with a dicing saw or the like, and divided into a plurality of piezoelectric elements 1. Next, a thermosetting resin 4 that reinforces strength and prevents acoustic coupling is filled in the gaps formed by the cuts between the piezoelectric elements 1.

[0005]

[Problems to be Solved by the Invention]
However, the array type probe having the above configuration has the following problem due to the thermosetting resin 4 filling the gap between the piezoelectric elements 1. That is, the thermosetting resin 4 contracts while being adhered to the piezoelectric element 1 after being cured by heating. The backing material 2 to which the piezoelectric element 1 is fixed is a rubber-based elastic body.

For this reason, for example, when the number of the piezoelectric elements 1 is two, the opening end side is pulled inward and contracts, and is inclined in a “C” shape (FIG. 5). Thereby, the plurality of piezoelectric elements 1
Is inclined toward the center from both ends, and particularly the inclination at both ends becomes large (FIG. 6). In addition, the resin 4 is peeled off to form a blank portion 5 (FIG. 7).

For this reason, after the resin is cured, basically, the width of the gap between the piezoelectric elements at both ends is larger than that at the center. Accordingly, the gap width (corresponding to the pitch) between the piezoelectric elements changes and becomes non-uniform, and the specified design value is not satisfied. In addition, since the piezoelectric elements 1 are inclined, the transmission and reception directions of ultrasonic waves do not match. By these,
For example, there is a problem that a tomographic image is different from an actual one.

Further, when a blank portion 5 of the resin 4 is formed between the piezoelectric elements 1, the gaps between the piezoelectric elements become uneven, the strength is weakened, and the piezoelectric element 1 collapses due to a pressing force at the time of diagnosis or the like. There was a problem.

In the case of the resin 4 having a large curing shrinkage, it may be cured at a low temperature. However, in this case, it takes too much time to deteriorate the productivity. Therefore, the resin 4 having a large curing shrinkage cannot be adopted even if the optimum acoustic condition is satisfied, and there is a problem that the range of options (design) is narrowed.

(Object of the Invention) It is an object of the present invention to provide a method of manufacturing an array-type probe in which a tomographic image is improved to maintain the strength, and the productivity is improved and the design width is expanded. I do.

[0011]

The basic solution of the present invention is to fill the piezoelectric element 1 by mechanically expanding the gap in consideration of the amount of shrinkage of the resin 4 after curing.

[0012]

According to the present invention, the gap between the piezoelectric elements 1 is widened and the resin 4
The gap width is made constant before and after the resin is cured. Hereinafter, an embodiment of the present invention will be described.

FIG. 1 and FIG. 2 are cross-sectional views in a manufacturing process of an array type 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 or omitted. As described above, the array type probes are first divided individually by a dicing saw,
A plurality of piezoelectric elements 1 having an acoustic matching layer 3 (ab) on the wave transmitting / receiving surface are arranged on a backing material 2 (FIG. 1).

In this embodiment, next, as shown in FIG. 2, the backing material 2 is pulled in both directions in the direction of the arrow.
Increase the width of each gap. Then, the resin 4 is filled. In this case, the gap width is set in consideration of shrinkage of the resin 4 due to curing shrinkage. Next, the resin 4 is cured while being pulled in both end directions. Finally, the pulling of the backing material 2 toward both ends is released, and the backing material 2 is returned to the original state.

In such a structure, when the resin 4 cures and contracts, the opening end side shrinks as described above, and the piezoelectric element 1 is inclined from both end sides toward the center (FIG. 6). And
By returning the backing material 2 to its original state, the resin 4 is pressed from both sides and pushed up, and the tilted piezoelectric element 1
Stands almost upright on the backing material 2. The resin 4 fills the gap (FIG. 4).

Thus, the width of the gap between the piezoelectric elements 1 can be formed according to a specified design value. That is, in consideration of the amount of shrinkage after curing, the backing material is pulled to widen the gap, and the resin is filled. Then, after the curing, the backing material is returned to the original state and the resin is pushed up, so that the gap can be widened accordingly. Therefore, even if the resin decreases due to curing shrinkage, the gap width can be formed as designed.

Further, since the resin 4 is reliably filled in the gap between the piezoelectric elements, the piezoelectric element 1 can be prevented from collapsing at the time of diagnosis or the like. Further, since the resin 4 can be cured at a high temperature, productivity can be maintained. Furthermore, since the resin 4 having a large curing shrinkage can be selected, the range of the design satisfying the optimal acoustic condition can be widened.

[0018]

[Second Embodiment] FIG. 3 is a cross-sectional view in a manufacturing process of an array type probe for explaining a second embodiment of the present invention. In addition,
The description of the same parts as those in the previous embodiment is omitted. In the second embodiment, the backing material 2 is curved to the rear side, the group of piezoelectric elements is formed into a fan shape, and the piezoelectric elements are inclined to both ends to widen the gap between the piezoelectric elements. Also in this case, the bending angle is controlled in consideration of the amount of shrinkage during curing shrinkage, and the amount of resin to be injected is determined. Then, in a state where the backing material 2 is curved, the gap between the piezoelectric elements is filled with the resin 4. Then, after curing, the backing material 2 is returned to its original flat state.

Also in this case, by returning the backing material 2 to its original state, the inclined piezoelectric element 1 is almost upright on the backing material 2 by the pushed up resin. Then, the resin 4 fills the gap. Therefore, even if the resin 4 decreases due to curing shrinkage, the gap width can be formed as designed. In addition, the collapse of the piezoelectric element 1 can be prevented, the productivity can be maintained, and the design range can be expanded.

[0020]

[Other matters] In the above embodiment, the second layer 3b of the acoustic matching layer is used.
To a specified thickness (eg, λ /
After step 4), the space between the piezoelectric elements is widened and the resin 4 is filled. That is, in a state where the second layer 3b of the acoustic matching layer is thickly applied, the gap between the piezoelectric elements is widened and the resin 4 is filled, and the backing material 2 is returned to the original state. You may. In this case, the transmitting and receiving wave surface including the filled resin can be flattened,
For example, when mounting an acoustic lens, it can be mounted evenly.

[0021]

According to the present invention, the gap between the piezoelectric elements is mechanically widened and filled in anticipation of the amount of shrinkage of the resin after curing, so that the tomographic image can be improved to maintain the strength and to improve the productivity. Thus, it is possible to provide a method for manufacturing an arrayed probe having a wider design range.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a step of manufacturing an ultrasonic probe illustrating an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a step of manufacturing the ultrasonic probe for explaining one embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a step of manufacturing an ultrasonic probe according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view of an ultrasonic probe illustrating a conventional example.

FIG. 5 is a partially enlarged cross-sectional view in a manufacturing process of an ultrasonic probe for explaining a problem of the conventional example.

FIG. 6 is a cross-sectional view in a manufacturing process of an ultrasonic probe for explaining a problem of the conventional example.

FIG. 7 is a cross-sectional view in a manufacturing process of an ultrasonic probe for explaining a problem of the conventional example.

[Explanation of symbols]

1 piezoelectric element, 2 backing material, 3 acoustic matching layer, 4
Resin, 5 blank space.

Claims (3)

[Claims] 1. A method of manufacturing an ultrasonic probe comprising arranging a plurality of piezoelectric elements in a width direction on a backing material with a gap and filling the gap with a resin, the amount of shrinkage of the resin after curing is estimated. The method according to claim 1, wherein the gap is mechanically widened and the resin is filled. 2. The method of manufacturing an ultrasonic probe according to claim 1, wherein said means for mechanically expanding said gap is a method of pulling said backing material toward both ends. 3. The method of manufacturing an ultrasonic probe according to claim 1, wherein said means for mechanically expanding said gap is a method of bending said backing material.