JP2601503B2 - Array type ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Regarding an array-type ultrasonic probe used as a sensor of an ultrasonic tomographic imaging apparatus, the structure of the array-type ultrasonic probe is reinforced to achieve acoustic matching with an electro-acoustic transducer. In order to prevent the occurrence of separation between layers, etc., it is formed by arranging a large number of micro-strip-shaped ultrasonic transmitting and receiving elements. An array-type ultrasonic wave comprising: an acoustic matching layer provided on the sound emitting side of the electroacoustic transducer via an electrode; and a sound absorber provided on the back side of the electroacoustic transducer via an electrode. In the probe, a foil-like metal net having a fine mesh is used as an earth line means for the earth taken out from one of the electrodes, and is fixed through the mesh of the metal net. The structure of the ultrasonic transmission / reception element is strengthened by using an adhesive means.

[Industrial applications]

The present invention relates to an array-type ultrasonic probe used as a sensor of an ultrasonic tomographic imaging apparatus, and more particularly, to an array-type ultrasonic probe whose structure itself can be strengthened.

In the construction method of the array type ultrasonic probe of the ultrasonic tomographic imaging device used for medical diagnosis, etc., the first step is
An acoustic matching layer and a sound absorber are formed on the upper and lower surfaces of an elongated plate-shaped piezoelectric element, which is an electroacoustic transducer, via electrodes, and a ground wire and a signal wire are extracted from these electrodes. By dividing the piezoelectric elements using a dicing saw or the like in the step (2), a two-stage manufacturing process of forming an array of ultrasonic transmitting / receiving elements is performed. Therefore, in the dividing step, a considerably large unreasonable force is applied to the generally formed ultrasonic probe.

In addition to the method of forming the acoustic matching layer, a method in which an acoustic matching layer previously formed to a thickness of a quarter wavelength is adhered onto the piezoelectric element, or the acoustic matching layer material is directly formed on the piezoelectric element. There is a case where a forming method is adopted in which a mold is formed and then formed by polishing to a thickness of a quarter wavelength. Even in such a method of forming the acoustic matching layer including the polishing step, a considerably large force is applied to the generally formed ultrasonic probe.

From now on, it is necessary to take measures to strengthen the structure of the array type ultrasonic probe.

[Conventional technology]

FIG. 3 shows a prior art structure of an array-type ultrasonic probe 20 formed by arranging a large number of minute ultrasonic transmitting / receiving elements 10 in a strip shape.

As shown in FIG. 1, the ultrasonic transmitting / receiving element 10 includes a piezoelectric element 1a, which is an electroacoustic transducer 1, an acoustic matching layer 4 provided on the sound wave radiation side of the piezoelectric element 1a, and a piezoelectric element 1a.
And a sound wave absorber 5 provided on the back side of the device.
The electrodes 2, 3 formed by silver baking on both sides of the piezoelectric element 1a for electroacoustic conversion are provided with a metal foil 8 for grounding, and a flexible printed board 7a for signals (with lead wires). However, they may be attached by soldering.

Acoustic matching layer 4 provided for acoustic matching
Is generally formed by stacking several layers of a mixture of an epoxy resin or the like and a metal powder, and is attached to the soldered piezoelectric element 1a of the metal foil 8 with an adhesive or directly by molding. Will be formed.

FIG. 4 shows a prior art obtained by improving the prior art shown in FIG. In this improved technique, a space formed between the metal foil 8 and the flexible printed board 7a is filled with an adhesive 9. As a result, the force applied to the soldered portion between the metal foil 8 and the electrode 2 and the soldered portion between the flexible printed board 7a and the electrode 3 can be reduced, and both the soldered portions can be protected. .

In any case, in the prior art, the metal foil 8 is used in order to share the ground of the ultrasonic transmitting / receiving elements 10 arranged in large numbers.

[Problems to be solved by the invention]

Silver foil or the like has been widely used as the metal foil 8, but the adhesive strength of the adhesive to the metal foil 8 is generally low. Particularly, in the method of directly molding the acoustic matching layer 4, a large amount of powder is contained in the epoxy resin. Adhesive strength will be further reduced due to the mixing of the bodies.

From this, in the prior art, the metal foil 8 and the acoustic matching layer 4
In addition, there has been a problem that the adhesive strength between the metal foil 8 and the flexible printed board 7a is not sufficient. FIG. 5 shows that when some force is applied to the metal foil 8 and the acoustic matching layer 4 in the manufacturing process including the dicing saw and the polishing, even if the conventional improved technology shown in FIG. As shown also, the bonding surface of the metal foil 8 and the acoustic matching layer 4 or the flexible printed board 7a of the metal foil 8 is easily peeled off, and as a result, the piezoelectric element 1a and the acoustic matching layer 4 are peeled off. .

If such peeling occurs even in one of the many ultrasonic transmitting / receiving elements 10, the array type ultrasonic probe 20 does not exhibit sufficient performance. Therefore, the conventional array-type ultrasonic probe 20 using the metal foil 8 for grounding has the disadvantages that the production yield is low and the reliability in use is not sufficient.

The present invention has been made in view of such circumstances,
Strengthening the structure of the array-type ultrasonic probe 20 by improving the adhesive strength of the adhesive to the metal foil 8 to prevent the occurrence of peeling or the like between the piezoelectric element 1a and the acoustic matching layer 4 It is intended for.

[Means for solving the problem]

The array-type ultrasonic probe according to the present invention is characterized in that a foil-like metal net having a fine mesh is used as an earth line means attached to the electroacoustic transducer of the ultrasonic transmitting / receiving element forming the array-type ultrasonic probe. It is configured to be used.

[Action]

According to the present invention, an adhesive means such as a molding agent or an adhesive used for forming the ultrasonic transmitting / receiving element is fixed integrally with the metal net through the mesh of the metal net. As a result, the metal net used as the ground line means and the adhesive means for forming the ultrasonic transmitting / receiving element do not peel off, so that the structure of the ultrasonic transmitting / receiving element can be strengthened.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing the internal structure of an array type ultrasonic probe 20 according to one embodiment of the present invention. As shown in this figure, the array type ultrasonic probe 20 of the present invention is also a third type.
The basic structure is the same as that of the conventional array-type ultrasonic probe 20 shown in the figure, and it is formed by arranging a large number of small ultrasonic transmitting and receiving elements 10 in a strip shape. An electroacoustic conversion element 1, for example, a piezoelectric element, an acoustic matching layer 4 provided on the sound emission side of the electroacoustic conversion element 1, and a sound absorption layer provided on the back side of the electroacoustic conversion element 1 And the body 5. Electrodes 2 and 3 are formed on the surface of the electro-acoustic transducer 1 that is in contact with the acoustic matching layer 4 and the surface that is in contact with the sound absorber 5 by baking silver or the like. A voltage for emitting a sound wave is applied, and a voltage excited by the ultrasonic wave returned from the test object is extracted.

Generally, a signal line means 7 such as a flexible printed board 7a is connected to the electrode 3 provided on the acoustic absorber 5 side by soldering, and a ground is provided to the electrode 2 provided on the acoustic matching layer 4 side. The earth line means to be taken is connected by soldering, but in the present invention,
As shown in FIG. 1, a foil-shaped metal net 6 having a fine mesh made of a material such as copper, brass, stainless steel or the like, which can be soldered, is used as the earth line means. It is desired that the mesh interval of the metal net 6 is sufficiently smaller than the arrangement pitch of the ultrasonic transmitting / receiving elements 10. However, it is not always necessary that the mesh has regularity like a normal wire net, and it is not necessary to form random holes. It can also be an array.

Next, how the array type ultrasonic probe 20 of the present invention using such a metal net 6 as an earth line means can strengthen its structure will be described with reference to FIG. The method will be described with reference to the explanatory diagram of the method.

As shown in FIG. 2 (A), first, the signal line means 7 is soldered to the end of the electrode 3 of the electroacoustic transducer 1 which is formed in advance, and thereafter, the sound absorber 5 is bonded or adhered. It is fixed to the electroacoustic transducer 1 via the electrode 3 by molding.

Next, as shown in FIG. 2 (B), a metal net 6 is soldered to the end of the electrode 2 of the electroacoustic transducer 1 which has been formed in advance, and thereafter, the acoustic matching layer material is electroacoustically converted. The lowermost layer 4a of the acoustic matching layer 4 is formed by directly molding on the element 1 and polishing to a thickness of a quarter wavelength. The other end of the metal net 6 is soldered to the signal line means 7 as ground. At this time, as shown in the figure,
Part of the acoustic matching layer material flows into the mesh of the metal net 6,
The metal net 6 is solidified in such a manner as to be sun-touched through this mesh. Therefore, the metal net 6, the acoustic matching layer 4, and the signal line means 7 are firmly fixed without being separated from each other.

Then, as shown in FIG. 2 (C), 2
After the acoustic matching layer 4 is formed by stacking the third and third layers, the array of the ultrasonic transmitting and receiving elements 10 as shown in FIG. Will be formed. Even when cutting with this dicing saw, the problem of peeling as shown in FIG. 5 does not occur because the structure is already reinforced by the metal net 6.

In the manufacturing method illustrated in FIG.
In this embodiment, the acoustic matching layer 4 is formed by directly molding the acoustic matching layer 4. However, a manufacturing method for bonding the previously formed acoustic matching layer 4 onto the electroacoustic transducer 1 is different from this. Also, since the adhesive used flows into the mesh of the metal net 6, the metal net 6, the acoustic matching layer 4 and the signal line means 7 are firmly fixed without being separated from each other.

As described above, according to the present invention, unlike the case where the conventional metal foil is used, the adhesive or the like does not peel off from the earth line means, so that the structure of the ultrasonic transmitting / receiving element 10 can be remarkably strengthened.

Although the illustrated embodiment has been described above, the present invention is not limited only to the above embodiment. For example,
The metal net 6 as the ground line means may be soldered to the electrode 3 on the sound absorber 5 side.
Further, the mesh shape of the metal net 6 is not particularly specified. The present invention can be applied to various array-type ultrasonic probes such as a sector phased array, a convex array, and a concave array.

〔The invention's effect〕

As described above, according to the present invention, the structure of the array type ultrasonic probe can be remarkably strengthened, and the ground line means and the acoustic matching layer which have conventionally occurred during the manufacturing process are separated from the electroacoustic transducer. And the like can be prevented, thereby significantly improving the production yield. The impact given during use after manufacture,
Since it is possible to prevent the earth line means and the acoustic matching layer from being peeled off due to the distortion caused by the temperature change, the reliability of the array type ultrasonic probe can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an array type ultrasonic probe according to one embodiment of the present invention, FIG. 2 is an explanatory view for explaining a method of manufacturing the array type ultrasonic probe shown in FIG. 1, FIG. 3 is a perspective view of a conventional array-type ultrasonic probe, FIG. 4 is a cross-sectional view of a conventional array-type ultrasonic probe obtained by improving the conventional technique of FIG. 3, and FIG. It is an explanatory view for explaining a problem. In the figure, 1 is an electroacoustic transducer, 1a is a piezoelectric element, 2, 3 are electrodes, 4
Is an acoustic matching layer, 5 is a sound absorber, 6 is a metal net, 7 is a signal line means, 7a is a flexible printed board, 8 is a metal foil, 9 is an adhesive, 10 is an ultrasonic transmitting / receiving element, and 20 is an array type super It is a sonic probe.

Claims (1)

(57) [Claims] 1. An ultrasonic transmission / reception element (10) formed by arranging a large number of small rectangular ultrasonic transmission / reception elements (10). An acoustic matching layer (4) provided on the sound wave emission side of (1) via an electrode (2), and the electroacoustic transducer (1)
An array-type ultrasonic probe (20) configured to include a sound absorber (5) provided on the back side of the device via an electrode (3), wherein one of the electrodes (2, 3) is provided. As a ground line means for ground taken out of the metal net, a foil-like metal net (6) having a fine mesh is used, and an adhesive means fixed through the mesh of the metal net (6) is used.
An array-type ultrasonic probe characterized by strengthening the structure of the ultrasonic transmitting / receiving element (10).