JPH029760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the manufacturing method of an ultrasonic probe equipped with a plurality of piezoelectric vibrators, and in particular to eliminating the adverse effects that occur when an acoustic matching layer is bonded to the piezoelectric vibrators. , relates to a method of manufacturing an ultrasonic probe that can improve acoustic characteristics.

Ultrasonic probes are widely used in ultrasonic diagnostic equipment and the like. In order to perform electronic scanning, it is necessary to use an array type ultrasonic probe in which a plurality of piezoelectric vibrators are arranged in one or more rows.

Such an array type ultrasonic probe has conventionally been produced by a process as shown in FIG.

That is, as shown in FIG. 1A, a holding member 1 such as a damper, etc.
A piezoelectric vibrator layer 2 is provided thereon by adhesive or the like.

Next, as shown in FIG. 1B, the acoustic matching layer 3 is bonded to the piezoelectric vibrator layer 2 with an adhesive 4 so as to cover the piezoelectric vibrator layer 2. Furthermore, as shown in FIG. 1C, the acoustic matching layer 3 and the piezoelectric vibrator layer 2 are cut into strips using a cutter or the like from the acoustic matching layer 3 side, and a plurality of piezoelectric vibrators 20 each having the separated acoustic matching layer 30 are formed. Form. If the holding member 1 is a damper, Fig. 1C
An array type ultrasonic probe is constructed in the form of a holding member 1.
If it is not a damper but a simple holder, it is removed from the holder and attached to a separately prepared damper to form an array-type ultrasonic probe.

In such a conventional manufacturing method, when bonding the piezoelectric vibrator layer 2 and the acoustic matching layer 3, since the bonding area between the two is large, there is no place for the adhesive 4 to sag. The layer thickness becomes thicker.

Therefore, acoustic attenuation and reflection to the adhesive layer 4 are likely to occur, and the apparent thickness of the acoustic matching layer 3 becomes large, causing problems in that it is difficult to achieve acoustic matching.

Furthermore, due to the large bonding area mentioned above, the non-uniformity of the thickness of the adhesive layer 4 becomes large, which may impede uniform acoustic characteristics, or make it difficult for air bubbles in the adhesive layer 4 to escape, resulting in adverse acoustic effects. is large.

The present invention has been made in view of the above points, and
Acoustic matching is ensured by the matching layer, and even when the area of the sound wave radiation surface is large, deterioration of acoustic characteristics due to adhesion of the acoustic matching layer is prevented, and
It is an object of the present invention to provide a method for manufacturing an ultrasonic probe that can form acoustic matching layers separated by a predetermined number of arranged piezoelectric vibrators. The present invention provides a method for manufacturing an ultrasonic probe.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 2 is a process explanatory diagram of an embodiment of the present invention,
Components that are the same as those shown in FIG. 1 are designated by the same symbols.

In the present invention, first, a plurality of rectangular piezoelectric vibrators 20 are formed on the holding member 1, as shown in FIG. 2A. For this purpose, as shown in FIG. 1A, a holding member 1
A layered piezoelectric vibrator 2 is formed on top, and an acoustic matching layer 3 is formed.
Before providing the piezoelectric vibrator layer 2, the piezoelectric vibrator layer 2 may be cut into strips to form a plurality of separated piezoelectric vibrators 20 in the strip shape. Such a strip-shaped piezoelectric vibrator 2
As a method of forming 0, there is also a method of arranging pre-cut piezoelectric vibrators 20 on the holding member 1.

Next, as shown in FIG. 2B, an acoustic matching layer 3 is provided so as to straddle the plurality of strip-shaped piezoelectric vibrators 20. The acoustic matching layer 3 is adhered to each separated strip-shaped piezoelectric vibrator 20 by an adhesive 4.

Furthermore, as shown in FIG. 2C, the acoustic matching layer 3 is cut to form separated acoustic matching layers 30.

As a result, an array type ultrasonic probe is formed.

The operation in the step shown in FIG. 2B described above will be explained in detail with reference to FIG. 3. FIG. 3 is a partial sectional view of FIG. 2B, in which the same parts as shown in FIG. 2 are designated by the same symbols.

A cutting groove 2 is formed between the separated piezoelectric vibrators 20.
1 is formed, so that when the acoustic matching layer 3 is bonded with the adhesive 4, the adhesive 4 is attached to the cutting groove 2.
You can escape little by little. For this reason, an effect similar to that of actually reducing the bonding area is created,
Since the thickness of the layer of adhesive 4 can be made very thin, acoustic attenuation and reflection are reduced. Moreover, unevenness of adhesive can be removed by this cutting groove 2.
Since air bubbles in the adhesive 4 can also be easily removed, adverse acoustic effects are reduced.

Furthermore, the cutting groove 2 of the piezoelectric vibrator is as shown in FIG.
Since it is hollow, it has the effect of acoustically shielding adjacent transducers from each other, improving the independence of each transducer, making it suitable for phase control etc. as an array type ultrasonic probe. characteristics can be obtained.

Moreover, when the piezoelectric vibrator 20 and the acoustic matching layer 3 are bonded together at a high temperature, warpage may occur in either one due to the difference in coefficient of expansion between the two, but in the present invention, the cutting groove 21 absorbs the expansion and contraction caused by the difference in expansion coefficients, so it can also be effective in preventing warping.

By the way, as in the acoustic matching layer 30 (FIG. 2C), the plate of the acoustic matching layer 3 is attached to the rectangular piezoelectric vibrator 2.
If the thin acoustic matching layer 3 is cut in accordance with all 0 points, the thin acoustic matching layer 3 is likely to crack during the cutting process, and it is extremely difficult to manufacture an ultrasonic probe having a large radiation surface. Therefore, in the present invention, as shown in FIG. 4, after steps A and B in FIG. 2, the acoustic matching layer 3 is cut so that one acoustic matching layer 31 is assigned to three piezoelectric vibrators 20.

In other words, the acoustic matching layer 31 not only ensures acoustic matching and prevents the acoustic characteristics of the acoustic matching layer 31 from deteriorating due to the adhesive even when the area of the sound wave radiation surface is large, but also prevents the acoustic matching layer 31 from deteriorating its acoustic characteristics due to the adhesive. Piezoelectric vibrator 2 is created by cutting the bonded plate.
They can be formed as separate acoustic matching layers each containing a predetermined number of zeros, which reduces cracking during the cutting process, improves yield, and simplifies the process. Furthermore, if the thickness-to-width dimension ratio of each piezoelectric vibrator 20 is close to 1 and the cross section is close to a square, the problem of generation of multiple vibration modes and deterioration of characteristics is also solved. That is, by cutting the acoustic matching layer 3 to include a predetermined number of piezoelectric vibrators 20,
This is equivalent to substantially increasing the width of the vibrator compared to its thickness, and it is possible to reliably excite in a single vibration mode and improve the characteristics.

As described above, according to the present invention, after forming a plurality of separated piezoelectric vibrators, the acoustic matching layer is bonded to the piezoelectric vibrators with an adhesive, so that the grooves between the separated piezoelectric vibrators are The adhesive layer can therefore be thinned. Moreover, in the process of cutting piezoelectric vibrators into acoustic matching layers each containing a predetermined number, separation between the vibrators is ensured, and cracks in the thin acoustic matching layers are less likely to occur, improving manufacturing yield. Acoustic attenuation and reflection are reduced, reducing the adverse acoustic effects of the adhesive, and since the thickness of the acoustic matching layer is not substantially increased, acoustic matching is not impaired. Further, by providing the above-mentioned escape area, non-uniformity in the thickness of the adhesive layer is eliminated, and air bubbles in the adhesive can be easily removed, so that the acoustic characteristics are further improved.

Furthermore, during high-temperature bonding, the grooves can absorb warpage due to the difference in expansion coefficients between the piezoelectric vibrator and the acoustic matching layer, thereby preventing warpage.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made in accordance with the gist of the present invention, and these are not excluded from the scope of the present invention.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional manufacturing method process, FIG. 2 is a process explanatory diagram of an embodiment of the present invention, FIG. 3 is a partial sectional view of a part of the process of FIG. It is an explanatory diagram of an example. The symbols in the figure indicate the following. 1... Holding member, 2... Piezoelectric vibrator layer, 3...
Acoustic matching layer, 4... Adhesive, 20... Piezoelectric vibrator, 21... Cutting groove, 30, 31... Separated acoustic matching layer.

Claims (1)

[Claims] 1. In a method for manufacturing an ultrasound probe in which an acoustic matching layer for matching the acoustic impedance of an object to be inspected is formed on the sound wave radiation surface side, a plurality of a step of forming a piezoelectric vibrator, a step of adhering a plate of a predetermined thickness that will become the acoustic matching layer so as to cover the entire radiation surface of the piezoelectric vibrator with an adhesive applied to the back surface thereof, 1. A method of manufacturing an ultrasonic probe, comprising the step of forming separate acoustic matching layers each containing a predetermined number of the piezoelectric transducers by cutting the plate.