JP2969162B2 - Ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe, and more particularly, to the propagation of heat generated during driving of a piezoelectric vibrator for generating ultrasonic waves and the dissipation of heat, thereby increasing the temperature of the surface of the vibrator. The present invention relates to an ultrasonic probe with reduced noise.

[0002]

BACKGROUND OF THE INVENTION As is well known, when a predetermined voltage is applied to a piezoelectric vibrator of an ultrasonic probe, its electric energy is converted into mechanical vibration energy, and an ultrasonic wave having a predetermined frequency is generated to propagate and radiate. Is done. In recent years, there has been a problem that heat from the piezoelectric vibrator generated during energy conversion causes various inconveniences. For example, safety issues such as a decrease in reliability due to insufficient strength due to thermal degradation of materials, a decrease in quality due to characteristic fluctuations due to a rise in temperature of each material, and a low-temperature burn to the skin of a living body during medical diagnosis. It is. For these reasons, there is a need for an ultrasonic probe that reduces these inconveniences. For example, one of them is an ultrasonic probe employing a heat radiation structure by the present applicant (see Japanese Patent Application Laid-Open No. 3-203290, H
1.12.28 application).

[0003]

2. Description of the Related Art FIG. 4 is an exploded view of an ultrasonic probe for explaining a conventional example of this type. The ultrasonic probe uses the piezoelectric vibrators 1 that are divided into a plurality and arranged in rows as a source of ultrasonic waves. The piezoelectric vibrator 1 has electrodes 2 (ab) on both main surfaces,
The other electrode 2b (referred to as signal electrode 2b) is alternately led out from the both ends by the flexible printed circuit board 3. Note that one electrode 2a (referred to as a common electrode 2a) is commonly connected and led out by a conductor (not shown). Then, the acoustic matching layer 4 is formed on one main surface side, and the other main surface side is attached to the backing material 5. On the lower surface side of the backing material 5, a heat radiation base 6 made of Al metal is used for heat radiation.
Is provided. Then, a metal thin film 7 (abc) connected to the heat radiating base 6 and the common electrode 2a of the piezoelectric vibrator 1 and surrounding the peripheral surface of the heat radiating base 6 is provided. The configuration up to this point is referred to as a probe main body 8 having a heat dissipation structure. Then, as shown in FIG. 5, the acoustic lens 9 is put on the surface of the probe main body 8 and housed in a case 11 made of a resin from which the cable 10 is led out.

[0004]

However, it has been difficult for the ultrasonic probe having such a configuration to continuously and effectively suppress the temperature rise on the surface of the transducer. That is, since the probe body 8 is housed in the case 10 and hermetically closed,
The amount of heat dissipated inside easily reaches its limit. Therefore, especially in the case of continuous driving for a long time, the amount of heat generated is large, and even if the heat from the vibrator surface is transmitted to the radiating base 6, the heat is not sufficiently released from the radiating base 6. . Further, since the heat radiating base 6 and the metal thin film 7b are connected by an adhesive (adhesive) (not shown), heat from the surface of the vibrator is blocked by the adhesive, and the heat is transmitted to the heat radiating base 6. In some cases, efficiency was reduced. From such a thing,
In particular, the bonded surface between the transducer surface and the acoustic matching layer is violated by heat,
There has been a problem that the acoustic characteristics are degraded due to destruction or peeling of the acoustic matching layer, thereby deteriorating reliability and quality, and impairing safety such as low-temperature burns.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to continuously and effectively suppress a temperature rise on a surface of a piezoelectric vibrator by transmitting and radiating heat of a piezoelectric vibrator generated by driving, thereby improving reliability, quality and safety. It is an object of the present invention to provide an ultrasonic probe that prevents a drop.

[0006]

According to the present invention, a heat conductive material is connected to the heat radiating base, and the heat conductive material is led out of a case in which the probe main body is housed. Less than,
An embodiment of the present invention will be described together with the operation.

[0007]

FIG. 1 is an exploded view of an ultrasonic 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. The ultrasonic probe is configured by housing the probe main body 12 in a case, similarly to the conventional example. The probe main body 12 forms the acoustic matching layer 4 on one main surface side and the backing material 5 on the other main surface side of the piezoelectric vibrator on which the common electrode 2a and the signal electrode 2b are formed. The signal electrodes 2 b and the like are led out from one end of the child 1 by the flexible printed circuit board 3. In this embodiment, the heat dissipation structure is as follows. That is,
A heat radiation base 6 made of Al is provided on the lower surface side of the backing material 5. Then, a metal thin film 7a made of Ag is joined to one end of the common electrode 2a of the piezoelectric vibrator 1 by soldering. For example, the metal thin film 7 a is joined to one end side of the piezoelectric vibrator 1 before division, and is cut and divided integrally with the acoustic matching layer 4. In addition, an insulating material 13 such as an adhesive is provided on one side surface of the piezoelectric vibrator 1 so that the metal thin film 7a and the signal electrode 2b are not short-circuited. It should be noted that reference numeral 2 in FIG.
Reference numeral 4 denotes an adhesive provided in the gap between the steps. And
A metal thin film 7b made of Cu is connected to the metal thin film 7a by solder, and is adhered so as to surround the peripheral side surface and the bottom surface of the heat radiating base 6. An adhesive is applied to the metal thin film 7b in advance. Further, on the bottom surface of the heat radiating base 6, a heat conductive material 14 such as an eccentric wire or a flat plate is provided with a fixing plate 15 for holding the metal thin film 7 b.
At the same time, it is pressed and fastened by the screw 16. The heat conductive material 14 is connected to the heat transfer wire 17 inside the case 11 and is led out of the case 11. Heat transfer wire 17
Is made of a conductor Cu or the like and is embedded in the cable 18.
FIG. 2 is a sectional view of the cable 18 provided with the heat transfer wire 17. The cable 18 is a coaxial multi-core type,
Is composed of a plurality of cables so as not to impair the flexibility of the cable 18. Then, the cable 18 is buried in the center of the cable 18 while being internally shielded by a mesh wire 19 or the like. In the drawings, reference numeral 20 denotes an insulator, reference numeral 21 denotes a mesh wire of an external shield, reference numeral 22 denotes a coating, and reference numeral 23 denotes an electrode lead wire in which a line connected to the signal electrode 2b and the common electrode 2a of each piezoelectric vibrator 1 is incorporated. is there.

With such a configuration, the heat generated from the piezoelectric vibrator 1 propagates through the metal thin film 7 (ab) and is stored in the base 6 made of a metal body. Then, the heat is radiated in the case 13. Further, the heat conduction wire 17 in the cable 14 propagates directly or indirectly through the heat conductor 14 and escapes from the probe main body 12 to the outside. In this embodiment, since the metal thin film 7b is more closely bonded to the heat conductive member 14 by the fixing plate 15, the propagation efficiency from the surface of the vibrator is improved without the interposition of an adhesive. Further, since the heat radiation base 6 is also tightly coupled, the shielding of heat by the adhesive is alleviated, and the propagation efficiency to the heat radiation base 6 is increased. FIG. 3 is a characteristic diagram showing the surface temperature of the acoustic matching layer 4 in comparison with that of the conventional example. The curve (a) is the present embodiment, and the curve (b) is the conventional example. The horizontal axis is the elapsed time (minutes) from the start, and the vertical axis is the surface temperature (° C.). In this experiment, the acoustic lens 9 was removed for the sake of convenience, and the surface temperature of the acoustic matching layer 4 was used instead of the oscillator surface temperature. From this experimental result, it can be seen that in the case of the present embodiment, at the time of starting (25
60 ° C.), the surface temperature is about 45 ° C., which is about 10 ° C. lower than the conventional example of 55 ° C., and it is understood that the heat radiation effect is good. For this reason, the temperature rise particularly at the bonding surface between the vibrator surface and the acoustic matching layer 4 is suppressed to prevent the acoustic matching layer 4 from deteriorating due to destruction or peeling of the acoustic matching layer 4. And the safety of low-temperature burns and the like can be maintained.

[0009]

[Other Matters] In the above embodiment, the flexible printed circuit board 3 is derived only from one side of the piezoelectric vibrator 1, but it may be derived alternately from both sides, for example. The metal thin film 7
May be coated with a resin or the like to maintain its strength, or a flexible printed circuit board may be used. Furthermore, although the metal thin film 7 uses Ag and Cu in combination from the viewpoint of thermal conductivity in consideration of economy, for example, the metal thin film 7 may be formed integrally from Ag or may be further divided into a plurality of pieces and soldered. Further, the heat radiating base 6 and the heat transfer wire 17 are thermally coupled using the heat conductive material 14, but the heat transfer wire 17 may be directly connected to the heat radiating base 6 and the fixing plate 15, In this sense, the heat conductive material described in the claims includes a heat transfer wire. Further, the heat transfer wire 17 is provided at the center of the cable 18 separately from the shielding mesh wire, but may be used as a shielding mesh wire or the like as needed. In short, in the present invention, as is apparent from the description of the claims, the limit of the heat capacity inside the case is intended to be eliminated by transferring heat to the outside of the case. Can be changed as appropriate.

[0010]

According to the present invention, a heat conductive material is connected to the heat radiating base, and the heat conductive material is led out of the case in which the probe main body is housed. It is possible to provide an ultrasonic probe that suppresses continuously and effectively and prevents a decrease in reliability, quality, and safety.

[Brief description of the drawings]

FIG. 1 is an exploded view of an ultrasonic probe for explaining an embodiment of the present invention.

FIG. 2 is a sectional view of a cable for explaining an embodiment of the present invention.

FIG. 3 is a temperature characteristic diagram for explaining the operation and effect of one embodiment of the present invention.

FIG. 4 is an exploded view of an ultrasonic probe for explaining a conventional example.

FIG. 5 is an external view of an ultrasonic probe.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 piezoelectric vibrator, 2 electrodes, 3 flexible printed circuit board, 4 acoustic matching layer, 5 backing material, 6 radiating base, 7 metal thin film, 8 and 12 probe body, 15 fixing base, 16 screws, 17 transmission Heat rays, 19 acoustic lenses,
10, 18 cable, 19, 21 mesh wire, 20 insulator, 22 coating, 23 electrode lead wire, 24 adhesive.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuo Shimizu 2275-12, Kamihirose, Oaza, Sayama-shi, Saitama Japan Radio Industry Co., Ltd. Sayama Office Examiner Matsuzawa Fukusaburo (56) References Hirai 3-122807 (JP , U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04R 17/00 330

Claims (1)

(57) [Claims] 1. A piezoelectric vibrator for generating ultrasonic waves having electrodes formed on both main surfaces, an acoustic matching layer formed on one main surface of the piezoelectric vibrator, and the other of the piezoelectric vibrators. A backing material attached to the main surface side, a metallic heat dissipation base holding the backing material, and heat conduction connecting the heat dissipation base and an electrode on one main surface of the piezoelectric vibrator. In an ultrasonic probe having a probe main body made of a thin film, a heat conductive material is connected to the heat radiating base, and the heat conductive material is led out of a case in which the probe main body is stored. An ultrasonic probe characterized in that: