JPS6323060Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ultrasonic probe used in an ultrasonic diagnostic apparatus using a pulse echo method.

The performance of an ultrasound probe (hereinafter simply referred to as a probe) is one of the factors that greatly influences the image quality of tomographic images obtained by ultrasound diagnostic equipment. The following points can be considered as specific points for obtaining clear images.

(b) To sharpen the directivity of the ultrasonic beam.

(b) Responsiveness of the transducer, that is, each transducer vibrates like a piston and transmits ultrasonic waves within a short period of time.

(c) Ultrasonic beam with small side ropes.

(d) The configuration must be such that the ultrasound transmitted from the transducer reaches the subject's body without being attenuated or subjected to unnecessary reflections along the route.

The present invention provides a probe that can satisfy the above (a) to (d).

FIG. 1 is a perspective view mainly showing the transducer array section of the probe of the present invention. In FIG. 1, 1a is a piezoelectric element made of, for example, lead zirconate titanate. 1b and 1c are electrode surfaces provided on both sides of the piezoelectric element 1a, and a vibrator 11 is constituted by the piezoelectric element 1a and the electrode surfaces 1b and 1c. Reference numeral 2 denotes an ultrasonic absorber, which is a backing material made of, for example, rubber mixed with metal powder. Vibrator 11
and the ultrasonic absorber 2 are bonded together as shown in FIG.
3 and 6 are printed boards, 3a and 6a are insulating boards,
3b and 6b are conductive patterns. Note that the printed board 3 is used to introduce a signal to excite each vibrator, and the printed board 6 is used to constitute a common electrode for each vibrator. 4 and 5 are conductive adhesives that have the effect of connecting the electrode surface of the vibrator 11 and the patterns of the printed boards 3 and 6. Note that in this specification, the term "conductive adhesive" also includes conductive paint.

The transducer 11 of the probe configured and arranged in this way
As shown in FIG. 1, the wafer is cut into strips to form a vibrator array. In this specification, each vibrator cut into small pieces in the shape of a tanzag is referred to as a vibrating fine element.
That is, a vibrator array is one in which vibrating microelements are arranged in an array.

FIG. 2 is a perspective view showing an example of a probe according to the present invention. In FIG. 2, first and second matching layers indicated by 7 and 8 are arranged in front of the transducer array of the probe shown in FIG. 1, and an acoustic lens 9 is further placed in front of the second matching layer. It has been established. The first matching layer 7 is made of glass, the second matching layer 8 is made of polymer film, and the acoustic lens 9 is made of silicone rubber.

The operation and features of the probe constructed in this manner as shown in FIG. 2 will be explained below. As shown in FIGS. 1 and 2, the vibrator 11 is cut into thin pieces into a vibrator array, and the depth of the cut portion is such that the conductive adhesive 4 is placed between every few pieces, as shown in section 4a, as shown in the figure. Also cut the . Therefore, a plurality of vibrators (five in the example of FIGS. 1 and 2) are excited simultaneously by one signal. In other words, conductive adhesive 4
The cut portions 4a are formed with a pitch larger than the arrangement pitch of the vibrating fine elements so that several adjacent vibrating fine elements are electrically connected to the electrode lead patterns 3b of the printed board 3 as one group. have. A plurality of such transducers in one group (5 pieces) are further arranged to constitute the probe shown in Figs. 1 and 2. However, when transmitting ultrasonic waves from the probe, multiple Ultrasonic waves that spread in the scanning direction (X-axis direction in FIG. 2) can be focused using a phased array method in which groups of 3 are excited in a certain time relationship. Further, the ultrasonic waves spreading in the thickness direction (Y-axis direction in FIG. 2) can be focused at the focal point of the acoustic lens 9 by the action of the acoustic lens 9. The ultrasonic beam obtained as a result has sharp directivity in both the X-axis and the Y-axis, and can satisfy the above-mentioned condition (a).

Next, it is known that in order to satisfy the characteristic (b) described above, the following structure may be used. That is, if the thickness of the vibrator is t, and the width of the vibrator cut into a tanzag shape is W, then W/t≦0.8. Generally, the thickness t of the transducer that transmits ultrasonic waves
is very thin, so in order to satisfy the above conditions, the width W for cutting into the tanzag shape must also be very narrow. Conventionally, signal electrode leads were attached to the electrode surface of the vibrator by bonding or the like, which required a space for bonding. Therefore, the width W of the vibrator needs to be a certain value or more, and it is difficult to satisfy the above-mentioned W/t≦0.8. Furthermore, since bonding was performed in a narrow space, the defective rate was extremely high. On the other hand, in the present invention, the electrode surface of the vibrator and the pattern on the printed circuit board are connected in advance by conductive adhesives 4 and 5 without bonding, and therefore does not have the drawbacks of the conventional means described above. The width W of the vibrator can be cut very narrowly. Therefore, the characteristic (b) described above can be satisfied.

Furthermore, as the width W of the vibrator is narrowed, the side ropes also become smaller in proportion to the width W, so that characteristics (b) and (c) can be satisfied at the same time.

In an ultrasonic diagnostic apparatus, it is necessary to efficiently transmit ultrasonic waves transmitted from a probe into the human body. That is, it is not preferable that the ultrasonic waves transmitted from the transducer are absorbed or reflected along the way. In the present invention, acoustic matching between the vibrator 11 and the human body is achieved by providing the first and second matching layers, thereby preventing absorption and reflection of the ultrasonic waves described above. That is, by using glass for the first matching layer 7, using a polymer film for the second matching layer 8, and using silicone rubber for the acoustic lens 9, the acoustic impedance is gradually brought closer to that of the human body. Prevents reflection.

As described above, the probe according to the present invention can satisfy the characteristics (a) to (d) described above, and as a result, a clear tomographic image can be obtained, which is extremely effective.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of a transducer array section of a probe according to the present invention, and FIG. 2 is a perspective view showing an example of a probe according to the present invention. 1a...piezoelectric element, 1b, 1c...electrode surface, 1
1... Vibrator, 2... Ultrasonic absorber, 3a, 6a
...Insulating substrate, 3b, 6b...Pattern, 3,6
...Printed board, 4,5...Conductive adhesive, 7...
...first matching layer, 8...second matching layer, 9...acoustic lens.

Claims (1)

[Claims for Utility Model Registration] (1) A bucking material, vibrating micro elements having two electrode surfaces and arranged in an array on one surface of the bucking material, a side surface of the bucking material that vibrates the vibration A printed board having a plurality of electrode lead patterns attached to face the vicinity of one end of the micro-element, several of the vibrating micro-elements adjacent to each other as one group electrically connected to the electrode lead pattern; A conductive adhesive is provided at a portion where one electrode surface of the vibrating micro-element and the printed board face each other, and has a cut portion formed with a pitch larger than the arrangement pitch of the vibrating micro-element so as to connect them to each other. layer and
An ultrasonic probe characterized in that first and second matching layers and an acoustic lens are provided in front of the array of vibrating microelements. (2) Glass as the material of the first matching layer;
The ultrasonic probe according to claim 1, characterized in that a polymer film is used as the matching layer of the ultrasonic probe. (3) The ultrasonic probe according to claim 1 or 2, characterized in that silicone rubber is used as the acoustic lens.