JPS6234197A - Sound wave absorbing body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] By dispersing an inorganic powder coated with an elastic material into a member formed of a thermosetting resin or a thermoplastic resin, a member formed of a thermosetting resin or a thermoplastic resin can be made to have a predetermined hardness and easy to process. It is designed to have a predetermined characteristic of absorbing ultrasonic waves.

[Industrial application field]

The present invention relates to a sound wave absorber fixed to a surface opposite to the sound wave emitting surface of a transducer element, and particularly relates to a sound wave absorber formed by dispersing inorganic powder coated with an elastic material in a synthetic resin. .

Ultrasonic probes used in ultrasound diagnostic equipment generally have a sound matching layer formed on the sound wave emission side of the transducer element for matching with the medium of the object, and a sound matching layer on the opposite side. A banking layer made of a sound wave absorber is formed to absorb unnecessary sound waves.

Furthermore, a soft material is used as such a backing layer in order to increase the attenuation of sound waves.

On the other hand, in such ultrasonic ultrasonic probes, the transducer element is sometimes used as an array type, and in this case, the transducer element is divided into predetermined pinches by dicing etc., and multiple transducer elements are A user element may be formed.

Therefore, such a backing layer is desired to be made of a material that has a hardness that allows easy processing such as dicing and has a high attenuation rate of ultrasonic waves.

[Conventional technology]

Conventionally, the structure was as shown in the sectional view of FIG.

A transducer element 12 provided with a matching layer 11 on the sound wave emission side is fixed to a backing layer 10 by adhesive or the like, and is configured so that unnecessary sound waves are absorbed by the backing layer 10.

This backing layer 10 is designed to increase the attenuation of sound waves.
It is formed by dispersing inorganic powder 2 such as tungsten powder in a member 1 made of relatively soft epoxy resin.

Further, when such a transducer element 12 is used as an array type, it is divided into predetermined pitches P by dicing or the like.

[Problems to be Solved by the Invention] In such a configuration, when the transducer element 12 is divided by dicing, the banking layer 10 is soft and deformed, resulting in poor workability.For example, the precision of the pitch P may be reduced. Furthermore, damage to the transducer element 12, cutting of the electrode, peeling of the matching layer 11, etc. may occur.

Therefore, it is possible to increase the hardness of the material of member l, but in this case, the attenuation of the sound waves will decrease, and in order to obtain good response characteristics, the thickness t will have to be increased. There was a problem in that the outer shape of the probe binding became large.

[Means for solving problems]

FIG. 1 is an explanation of the principle of the present invention.

As shown in FIG. 1, a member 11'/' made of thermosetting resin or thermoplastic resin and a coating/
3. Inorganic powder/2g having a true density of 2g/cr1 or more is formed on the surface, and a predetermined amount of 12g of the inorganic powder is dispersed in the member Fl/.

[For production]

In other words, it is constructed by dispersing inorganic powder with an elastic coating on its surface into a synthetic resin material, so that even if the synthetic resin material is hard, the elastic material of the coating can absorb sound waves. It can be formed to provide an absorption effect.

Therefore, it is possible to obtain a hardness with good workability and a predetermined attenuation of sound waves.

〔Example〕

The same reference numerals indicate the same objects throughout the figures.

As shown in FIG. 2, the structure is such that a predetermined amount of inorganic powder 2, on which a relatively soft elastic coating 3 is formed, is dispersed in a hard member 1.

This inorganic powder 2 has a true density of 2 g/co! Any of the above particles can basically be used, but the particle size is preferably 100 μm or less in order to reduce scattering of sound waves.

The coating 3 is made of an organic polymer that is elastic at room temperature, such as silicone rubber or urethane rubber.

It is made of nitrile rubber, styrene rubber, etc.

Further, the member 1 may be a thermosetting resin or a thermoplastic resin such as an epoxy resin, a phenol resin, or a cyatulphthalate resin that hardens at room temperature.

Such a configuration can be manufactured as follows.

Iron oxide (Fe203) powder with a particle size of 5 to 40 μm is immersed in a solution of thermosetting silicone rubber diluted with toluene, stirred well, excess solution removed, and dried at room temperature to evaporate the toluene. . Then heated to 150℃ using an electric furnace.
Heat and harden the silicone rubber.

The iron oxide powder thus treated was mixed with Ciba Geigy's epoxy resins XN1019 and XN1113 at a weight ratio of 2:3.
After mixing and dispersing the mixture at a volume mixing ratio of 1:1, the mixture is vacuum degassed and heated and cured at 120°C in an electric furnace.

When manufactured in this way, the attenuation rate of the sound wave is 6dB
/van, and the attenuation rate is 2 to 3 times that of the conventional one without the elastic coating 3, and the hardness is approximately 83 on the Shore D scale of the Shore hardness tester, which is sufficient for practical use. I got f-9.

In this way, when a soft rubber-like resin is coated on the surface of an inorganic powder such as a metal, a totally bent oxide, or an organic powder, and this powder is mixed and dispersed in a hard resin and cured, it becomes hard as a whole. However, it is possible to form a solid substance covered with a soft rubber-like resin only around the dispersed powder.

When sound waves propagate through such a solid object, the powder is surrounded by a soft resin, which makes it easy to vibrate, and the energy of the received sound waves is converted into frictional heat due to the vibrations.

Therefore, although the hardness is high as a whole, the attenuation of sound waves can be increased.

〔Effect of the invention〕

As explained above, according to the present invention, the matching layer can be made of a hard material with high hardness, so that damage to the transducer element, cutting of the electrode, peeling of the matching layer, etc. that conventionally occur can be prevented. At the same time, deformation during processing for dividing the transducer element into strips does not occur, improving workability and improving processing accuracy.

Furthermore, since the attenuation of the sound waves is increased, even if the thickness L of the backing layer is reduced, good response characteristics can be obtained and the ultrasonic probe can be made smaller, which has great practical effects.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a sectional view of an embodiment according to the present invention. FIG. 3 shows a conventional sectional view. In the figure, 1 is the component, 2 is the inorganic powder. 3 indicates a coating.

Claims (1)

[Claims] A member (1) that is a sound absorber that is fixed to a predetermined location of a transducer element that transmits or receives ultrasonic waves and absorbs the ultrasonic waves, and is made of thermosetting resin or thermoplastic resin. And, the true density of the elastic material coating (3) formed on the surface is 2 g/
cm^3 or more inorganic powder (2), the inorganic powder (
A sound wave absorber characterized in that a predetermined amount of (2) is dispersed in the member (1).