US20110114303A1 - Ultrasonic probe having heat sink - Google Patents

Abstract

The present invention provides an ultrasonic probe which includes a heat sink (150) provided in a rear layer (140) to dissipate heat. The heat sink is coupled to a rear surface (141) of the rear layer such that contact area there between are increased. The heat sink includes a plurality of heat conductive protrusions (151) on one surface thereof. The heat conductive protrusions are inserted into respective heat conductive depressions (142) formed in the rear layer. Each heat conductive depression has a shape corresponding to the respective heat conductive protrusion. Preferably, each heat conductive protrusion has a bar shape.

Description

TECHNICAL FIELD
• The present invention relates, in general, to ultrasonic probes and, more particularly, to an ultrasonic probe having a heat sink which prevents deterioration of the characteristics of a piezoelectric device, thus preventing deterioration in performance and durability of the ultrasonic probe, and also prevents an acoustic lens from becoming excessively heated, thereby reducing the temperature of the surface of the ultrasonic probe in contact with a patient.
BACKGROUND ART
• Generally, ultrasonic imaging apparatuses mainly include an ultrasonic probe which performs conversion between electric and ultrasonic signals, a signal processing unit which processes transmitted or received signals, and a display which expresses images by using signals received from the ultrasonic probe and signals processing unit.
• The ultrasonic probe performing signal conversions is a very important part determining the quality of ultrasonic images. In detail, the ultrasonic probe performs conversion between electrical energy and acoustic energy. The ultrasonic probe must satisfy basic conditions: which are good electric-acoustic conversion efficiency (electromechanical coupling coefficient), ultrasonic pulse characteristics, and focusability of ultrasonic beams.
• A representative example of conventional medical ultrasonic probes will be explained with reference to the attached drawings.
• FIG. 1 is a cross sectional view illustrating a conventional medical ultrasonic probe. As shown in the drawing, the medicalultrasonic probe10 includes anacoustic lens11, amatching layer12, apiezoelectric device13 and arear layer14, which are arranged in sequence from a front front end contacting with a patient.
• Theacoustic lens11 covers the front surface of thematching layer12 and functions to focus ultrasonic waves.
• Thematching layer12 is provided on an electrode of an ultrasonic wave sending/receiving surface of thepiezoelectric device13 and functions to enhance the reflectivity and efficiency of ultrasonic waves.
• Thepiezoelectric device13 is attached to the front surface of therear layer14 and is connected to a main PCB (printed circuit board) through a FPCB (flexible printed circuit board;15). Thepiezoelectric device130 converts electrical signals into ultrasonic waves which are acoustic signals and emits the ultrasonic waves into air. As well, thepiezoelectric device130 converts ultrasonic reflection signals, which are returned from air by reflection, into electrical signals and transmits the electrical signals to a main apparatus.
• Therear layer14 is fastened to acasing16 in such a way as to apply silicon to therear layer14 and thecasing16 after they are closed together. Therear layer14 functions to absorb ultrasonic waves which are undesirably emitted backwards.
• According to the intended purpose, the conventional medicalultrasonic probes10 having the above-mentioned construction are classified into two kinds of probes, i.e., an image sensing probe of image diagnostic apparatuses and, a medical treatment probe used in HIFU (high intensity focused ultrasound) treatment systems for cancer treatment or fat burning.
• With regard to the ultrasonic probes used for imaging, recently, the number of devices mounted to a small area of the ultrasonic probes has gradually increased to enhance the resolution. Here, small devices increase the difference in electrical impedance between the image diagnostic apparatuses and the probes, so that electrical energy which is not converted into ultrasonic waves is converted into thermal energy and is lost.
• The ultrasonic probe used for medical treatment requires relatively high output, unlike the ultrasonic probe for imaging. Thus, the amount of heat generated from devices used in the probe is higher.
• Heat generation in such a mediCal ultrasonic probe must be restrained due to the two following reasons.
• First, the piezoelectric device used in the ultrasonic probe has the characteristic that it cannot stand much heat. Therefore, if the ultrasonic probe is continuously maintained at a high temperature, the characteristics of the piezoelectric device deteriorate, resulting in deterioration of performance and durability of the probe.
• Second, the ultrasonic probe is typically brought into contact with a patient when it is in operation, so that the temperature of the contact surface of the ultrasonic probe with the patient must be limited. In the case of ultrasonic probes which generate a lot of heat, a comparatively low voltage is applied to the ultrasonic probe when it is operated, because the temperature of the contact surface of the ultrasonic probe with the patient must not exceed the limiting temperature owing to heat generation of the ultrasonic probe itself. However, this decreases the output of the ultrasonic probe, thus deteriorating the performance thereof.
DISCLOSURE OF INVENTIONTechnical Problem
• In an effort to overcome the above-mentioned problems experienced with the conventional medical ultrasonic probes, as methods of restraining heat generation to prevent deterioration of the performance and durability of the ultrasonic probes, a piezoelectric device having a high dielectric constant may be used, and heat dissipation efficiency of the ultrasonic probe may be increased.
• In the case where the piezoelectric device having a high dielectric constant is used, because a difference in electrical impedance between the piezoelectric device and the system is reduced, heat generation of the ultrasonic probe can be restrained. Though, a stack type piezoelectric device or a piezoelectric device having a high dielectric constant may be used to achieve the above purposes, there is a limitation owing to limited availability of such piezoelectric device or difficulty in manufacturing the stack type piezoelectric device.
• Furthermore, even if a rear layer is made of material having high heat conductivity to increase heat diffusion, there is a limitation in the use of material having high heat conductivity in that the rear layer must satisfy a damping characteristic of an ultrasonic wave. In particular, in the case of the structure for increasing the heat dissipation efficiency of the ultrasonic probe, there is a restriction in that heat generation in a contact surface of the probe with a patient must be minimized and such heat dissipation structure must not affect the performance of the ultrasonic probe.
• Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an ultrasonic probe which is constructed such that heat is dissipated through a rear layer to prevent heat from being emitted through a contact surface contacting with a patient and such heat dissipation structure does not deteriorate the performance of the ultrasonic probe.
Solution to Problem
• In order to accomplish the above object, the present invention provides an ultrasonic probe which includes a heat sink provided in a rear layer to dissipate heat.
Advantageous Effects of Invention
• In the present invention, heat generated from a piezoelectric device is rapidly conducted to a heat sink via a rear layer and dissipated. Therefore, deterioration in characteristics of the piezoelectric device can be prevented, so that deterioration in performance and durability of the ultrasonic probe can be prevented. As well, a temperature of the contact surface of the ultrasonic probe with the patient can be reduced by preventing heat generation in an acoustic lens. Furthermore, ultrasonic waves absorbed into the rear layer are prevented from being re-reflected towards the front surface of the rear layer, so that the performance of the ultrasonic probe can be maintained.
BRIEF DESCRIPTION OF DRAWINGS
• FIG. 1 is a cross sectional view illustrating a conventional medical ultrasonic probe;
• FIG. 2 is a perspective view illustrating an ultrasonic probe having a heat sink in accordance with a first embodiment of the present invention;
• FIG. 3 is a cross sectional view of the ultrasonic probe having the heat sink in accordance with the first embodiment of the present invention;
• FIG. 4 is a perspective view showing the heat sink of the ultrasonic probe in accordance with the first embodiment of the present invention;
• FIG. 5 is a perspective view illustrating an ultrasonic probe having a heat sink, in accordance with a second embodiment of the present invention;
• FIG. 6 is a cross sectional view of the ultrasonic probe having the heat sink in accordance with the second embodiment of the present invention;
• FIG. 7 is a perspective view showing the heat sink of the ultrasonic probe in accordance with the second embodiment of the present invention;
• FIG. 8 is a cross sectional view of an ultrasonic probe having a heat sink in accordance with a third embodiment of the present invention;
• FIG. 9 is a perspective view showing the heat sink of the ultrasonic probe in accordance with the third embodiment of the present invention;
• FIG. 10 is a cross sectional view of an ultrasonic probe having a heat sink in accordance with a fourth embodiment of the present invention;
• FIG. 11 is a perspective view showing the heat sink of the ultrasonic probe in accordance with the fourth embodiment of the present invention;
• FIG. 12 is a cross sectional view of an ultrasonic probe having a heat sink in accordance with a fifth embodiment of the present invention; and
• FIG. 13 is a perspective view showing the heat sink of the ultrasonic probe in accordance with the fifth embodiment of the present invention.
MODE FOR THE INVENTION
• Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the present invention, detailed explanation of well-known functions and constructions will be omitted so that the present invention can be described more clearly.
• FIG. 2 is a perspective view illustrating anultrasonic probe100 having aheat sink150, in accordance with a first embodiment of the present invention.FIG. 3 is a cross sectional view of theultrasonic probe100 having theheat sink150 in accordance with the first embodiment of the present invention.FIG. 4 is a perspective view showing theheat sink150 of theultrasonic probe100 in accordance with the first embodiment of the present invention. As shown in the drawings, theultrasonic probe100 having theheat sink150 in accordance with the first embodiment of the present invention includes, from the front end to be contacted with a patient sequentially, anacoustic lens110, amatching layer120, apiezoelectric device130 and arear layer140. Theheat sink150 is provided in therear layer140.
• Theacoustic lens110 is attached to the matchinglayer120 in a shape which covers the front surface of thematching layer120. Theacoustic lens110 serves to focus ultrasonic waves.
• Thematching layer120 is provided on an electrode of an ultrasonic wave receive/send surface of thepiezoelectric device130 to increase ultrasonic wave transmitting efficiency and reflectivity of ultrasonic waves.
• Thepiezoelectric device130 is adhered to the front surface of therear layer140. First and second electrodes which are connected to a PCB (not shown) through an FPCB160 (flexible printed circuit board) are provided on the respective opposite surfaces of thepiezoelectric device130. Thepiezoelectric device130 converts electrical signals into ultrasonic waves, which are acoustic signals, and emits the ultrasonic waves into air. Thepiezoelectric device130 converts ultrasonic reflection signals, which are returned from the air by reflection, into electrical signals and transmits the electrical signals to a main apparatus.
• Therear layer140 is coupled to theheat sink150 and absorbs unnecessary ultrasonic waves that are emitted backwards. For the coupling with theheat sink150, therear layer140 may be integrally molded with theheat sink150.
• Theheat sink150 is made of high heat conductivity, e.g., metal such as aluminum (Al) and copper (Cu). Theheat sink150 is fastened to arear surface141 of therear layer140, that is, to a surface of therear layer140 which is opposite the surface to which thepiezoelectric device130 is adhered. Theheat sink150 is fastened to acasing170 by applying silicon to theheat sink150 and thecasing170 after they are closed together.
• It is preferable that theheat sink150 is coupled to therear surface141 of therear layer140 such that the contact area therebetween can be large enough to increase heat transfer therebetween. To achieve the above purpose, a plurality ofheat transfer protrusions152 for increasing heat transfer efficiency with therear layer140 is provided on one surface of abase body151 of theheat sink150. Furthermore, a plurality of heatconductive depressions142 which have shapes corresponding to the heatconductive protrusions152 is formed in therear layer140, so that the heatconductive protrusions152 are inserted into the respective heatconductive depressions142. As such, because therear layer140 has the heatconductive depressions142 having shapes corresponding to the heatconductive protrusions152, a closer contact between the heatconductive depressions142 and the heatconductive protrusions152 is provided, thus enhancing heat transfer between therear layer140 and theheat sink150.
• As shown inFIG. 4, each heatconductive protrusion152 preferably has a bar shape, thus maximizing the contact area with therear layer140 which is connected to the heatconductive protrusions152 through the heatconductive depressions142.
• In theultrasonic probe100 having theheat sink150 in accordance with the first embodiment of the present invention having the above-mentioned construction, heat generated from thepiezoelectric device130 is conducted to theheat sink150 via therear layer140 and dissipated, thus increasing a heat transfer rate to therear layer140. In particular, because theultrasonic probe100 is constructed such that the heatconductive protrusions152 of theheat sink150 are inserted into the respective heatconductive depressions142 of therear layer140, the contact surface between therear layer140 and theheat sink150 is increased, so that the heat transfer from therear layer140 to theheat sink150 can be markedly enhanced.
• As such, in the present invention, heat generated from thepiezoelectric device130 can be rapidly dissipated by using theheat sink150. Therefore, thepiezoelectric device130 can be protected from heat, thus preventing deterioration in characteristics of thepiezoelectric device130. In addition, therear layer140 can maintain its ultrasonic attenuation characteristic. Accordingly, deterioration in performance and durability of theultrasonic probe100 can be prevented. Further, since heat conduction to theacoustic lens110 is reduced, the temperature of the contact surface of theultrasonic probe100 to be contacted with the patient can be reduced.
• FIG. 5 is a perspective view illustrating anultrasonic probe200 having aheat sink250 in accordance with a second embodiment of the present invention.FIG. 6 is a cross sectional view of theultrasonic probe200 having theheat sink250 in accordance with the second embodiment of the present invention. As shown in the drawings, theultrasonic probe200 having theheat sink250 in accordance with the second embodiment of the present invention includes, sequentially from the front end to be brought into contact with a patient, anacoustic lens210, amatching layer220, apiezoelectric device230 and arear layer240. Theheat sink250 is provided in therear layer240. The general construction of theultrasonic probe200 in accordance with the second embodiment, except for theheat sink250, remains the same as that of theultrasonic probe100 in accordance with the first embodiment, and therefore further explanation is deemed unnecessary.
• To couple theheat sink250 to therear layer240 such that the contact area therebetween are increased, heatconductive protrusions252 are perpendicularly provided on one surface of abase body251 of theheat sink250 and are inserted into respective heatconductive depressions242 which are formed in therear layer240. As shown inFIG. 7, each heatconductive protrusion252 has a bar shape which has aninclined surface252aon an end thereof to form an acute end.
• Each of the heatconductive depressions242 of therear layer240 has a shape corresponding to that of the corresponding heatconductive protrusion252, so that the entire surfaces of heatconductive protrusions252 can be in close contact with therear layer240.
• In theultrasonic probe200 having theheat sink250 in accordance with the second embodiment of the present invention having the above-mentioned construction, heat generated from thepiezoelectric device230 is rapidly conducted to theheat sink250 via therear layer240 and is dissipated, thus preventing deterioration of characteristics of thepiezoelectric device230. Accordingly, deterioration in performance and durability of theultrasonic probe200 can be prevented. As well, the temperature of the contact surface of theultrasonic probe200 to be contacted with the patient can be reduced by virtue of a reduction in temperature of theacoustic lens210.
• Furthermore, as shown inFIG. 6, ultrasonic waves absorbed into therear layer240 are reflected in transverse directions by theinclined surfaces252athat are formed on the heatconductive protrusions252 of theheat sink250. Thus, ultrasonic waves absorbed into therear layer240 are prevented from being re-reflected towards the front surface of theultrasonic probe200, so that the ultrasonic waves can be reabsorbed in therear layer240 and thus extinguished. Therefore, the intended purpose of therear layer240, that is, the purpose of absorbing back reflection waves, can be achieved, thus preventing deterioration in performance of theultrasonic probe200.
• FIG. 8 is a cross sectional view of anultrasonic probe300 having aheat sink350 in accordance with a third embodiment of the present invention.FIG. 9 is a perspective view showing theheat sink350 of theultrasonic probe300 in accordance with the third embodiment of the present invention. As shown in the drawings, theultrasonic probe300 having theheat sink350 in accordance with the third embodiment of the present invention includes, sequentially from the front end which is to be brought into contact with a patient, anacoustic lens310, amatching layer320, apiezoelectric device330 and arear layer340. Theheat sink350 is provided in therear layer340. The general construction of theultrasonic probe300 in accordance with the third embodiment, except for theheat sink350, remains the same as that of theultrasonic probe100 in accordance with the first embodiment, therefore further explanation is deemed unnecessary.
• To couple theheat sink350 to therear layer340 such that the contact area therebetween is increased, heatconductive protrusions352 are perpendicularly provided on one surface of abase body351 of theheat sink350 and are inserted into respective heatconductive depressions342 which are formed in therear layer340. Each heatconductive protrusion352 is formed in a bar shape and has therein aninsert hole352awhich penetrated from the distal end of the heatconductive protrusion352 towards the proximal end thereof.
• Theinsert hole352ahas a conical shape to prevent ultrasonic waves absorbed into therear layer340 from being re-reflected towards the front surface of theultrasonic probe300 by theheat sink350.
• Each of the heatconductive depressions342 of therear layer340 has a shape corresponding to that of the corresponding heatconductive protrusion352, so that the entire surface of heatconductive protrusions352 can be in close contact with therear layer340. In other words, each heatconductive depression342 has a shape capable of receiving the corresponding heatconductive protrusion352, and aninsert protrusion342ais provided in each heatconductive depression342 and inserted into theinsert hole352aof the corresponding heatconductive protrusion352.
• In theultrasonic probe300 having theheat sink350 in accordance with the third embodiment of the present invention having the above-mentioned construction, heat generated from thepiezoelectric device330 is rapidly conducted to theheat sink350 via therear layer340 and is dissipated, thus preventing deterioration of characteristics of thepiezoelectric device330. Accordingly, deterioration in performance and durability of theultrasonic probe300 can be prevented. As well, the temperature of the contact surface of theultrasonic probe300 to be contacted with the patient can be reduced by virtue of a reduction in temperature of theacoustic lens310.
• Furthermore, ultrasonic waves absorbed into therear layer340 are repeatedly reflected by the inner surfaces of the insert holes352aof theheat sink350 and are eventually cancelled out, thus reducing reflection of the ultrasonic waves towards the front surface of therear layer340, thereby preventing deterioration in performance of theultrasonic probe300.
• FIG. 10 is a cross sectional view of anultrasonic probe400 having aheat sink450 in accordance with a fourth embodiment of the present invention.FIG. 11 is a perspective view showing theheat sink450 of theultrasonic probe400 in accordance with the fourth embodiment of the present invention. As shown in the drawings, theultrasonic probe400 having theheat sink450 in accordance with the fourth embodiment of the present invention includes, sequentially from the front end which is to be brought into contact with a patient, anacoustic lens410, amatching layer420, apiezoelectric device430 and arear layer440. Theheat sink450 is provided in therear layer440. The general construction of theultrasonic probe400 in accordance with the fourth embodiment remains the same as that of theultrasonic probe100 in accordance with the first embodiment except for theheat sink450, and therefore further explanation is deemed unnecessary.
• To couple theheat sink450 to therear layer440 such that the contact area therebetween is increased, heatconductive protrusions452 are perpendicularly provided on one surface of abase body451 of theheat sink450 and are inserted into respective heatconductive depressions442 which are formed in therear layer440. Each heatconductive depression442 has a shape corresponding to that of the corresponding heatconductive protrusion452. Each heatconductive protrusion452 has a conical shape to prevent ultrasonic waves absorbed into therear layer440 from being re-reflected towards the front surface of therear layer440.
• Furthermore, each of the heatconductive depressions442 of therear layer440 has a shape, i.e., a conical shape, corresponding to the corresponding heatconductive protrusion452, so that the entire surface of the heatconductive protrusions452 can be in close contact with therear layer440.
• In the same manner as the prior embodiments, in theultrasonic probe400 having theheat sink450 in accordance with the fourth embodiment of the present invention having the above-mentioned construction, heat generated from thepiezoelectric device430 is rapidly conducted to theheat sink450 via therear layer440 and is dissipated, thus preventing deterioration of characteristics of thepiezoelectric device430. Accordingly, deterioration in performance and durability of theultrasonic probe400 can be prevented. As well, the temperature of the surface of theultrasonic probe400 coming into contact with the patient can be reduced by virtue of a reduction in temperature of theacoustic lens410.
• Furthermore, since ultrasonic waves absorbed into therear layer440 are reflected in transverse directions by the conical heatconductive protrusions452 of theheat sink450, the ultrasonic waves are prevented from being re-reflected towards the front surface of therear layer440 and are reabsorbed into portions of therear layer440 which are disposed around the heatconductive protrusions452. The reabsorbed ultrasonic waves are eventually cancelled out. Therefore, deterioration in performance of theultrasonic probe400 can be prevented.
• FIG. 12 is a cross sectional view of anultrasonic probe500 having aheat sink550 in accordance with a fifth embodiment of the present invention.FIG. 13 is a perspective view showing theheat sink550 of theultrasonic probe500 in accordance with the fifth embodiment of the present invention. As shown in the drawings, theultrasonic probe500 having theheat sink550 in accordance with the fifth embodiment of the present invention includes, sequencially from the front end which is to be brought into contact with a patient, anacoustic lens510, amatching layer520, apiezoelectric device530 and arear layer540. Theheat sink550 is provided in therear layer540. The general construction of theultrasonic probe500 in accordance with the fifth embodiment, except for therear layer540 and theheat sink550, remains the same as that of theultrasonic probe100 in accordance with the first embodiment, and therefore further explanation is deemed unnecessary.
• With regard to the coupling of theheat sink550 to therear layer540, aninsert part552 is provided on one surface of abase body551 of theheat sink550 and is embedded in the rear surface541 of therear layer540.
• It is preferable that theinsert part552 be made of awire552ahaving a coil shape to increase heat conductivity between therear layer540 and theheat sink550.
• Theinsert part552 includes a plurality of coil-shapedwires552awhich are, for example, arranged in parallel with each other on abase body551 of theheat sink550. Each coil-shapedwire552amay be provided in such a way that the opposite ends thereof are integrated with thebase body551 when thebase body551 is formed or, alternatively, in such a way that the opposite ends thereof force-fitted into thebase body551. Furthermore, the coil-shapedwires552ais embedded in therear layer540 when therear layer540 is formed on thebase body551 of theheat sink550 by molding. Accordingly, thebase body551 of theheat sink550 is coupled to therear layer540. Furthermore, interference with ultrasonic waves absorbed into therear layer540 is minimized, thus preventing the ultrasonic waves from being re-reflected towards the front surface of therear layer540.
• In the same manner as the prior embodiments, in theultrasonic probe500 having theheat sink550 in accordance with the fifth embodiment of the present invention having the above-mentioned construction, heat generated from thepiezoelectric device530 is rapidly conducted to theheat sink550 via therear layer540 and is dissipated, thus preventing deterioration of characteristics of thepiezoelectric device430. Accordingly, deterioration in performance and durability of theultrasonic probe400 can be prevented. Further, the temperature of theacoustic lens410 can be reduced. In particular, the coil-shapedwires552awhich are embedded in therear layer540 serve to increase the area of a heat conduction passage between therear layer540 and theheat sink550, thus further enhancing the heat transfer efficiency of theheat sink550.
• As well, in the fifth embodiment, since ultrasonic waves absorbed into therear layer540 pass between the coil-shapedwires552a, the ultrasonic waves are prevented from being re-reflected towards the front surface of therear layer540, thus preventing deterioration in performance of theultrasonic probe500.
• As described above, in accordance with the preferred embodiments of the present invention, heat generated from a piezoelectric device is rapidly conducted to a heat sink via a rear layer and dissipated. Therefore, deterioration in characteristics of the piezoelectric device can be prevented, so that deterioration in performance and durability of the ultrasonic probe can be prevented. Further, the temperature of the surface of the ultrasonic probe which comes into contact with the patient can be reduced by virtue of a reduction in temperature of the acoustic lens.
• Furthermore, ultrasonic waves absorbed into the rear layer are prevented from being re-reflected towards the front surface of the rear layer, so that the performance of the ultrasonic probe can be maintained. In addition, heat conductive protrusions of the heat sink have shapes to prevent absorbed ultrasonic waves from being re-reflected towards the front surface of the rear layer. Hence, the present invention can overcome a disadvantage in which the heat sink cannot be disposed adjacent to the piezoelectric device due to the possibility of re-reflection of ultrasonic waves to the front surface of the rear layer. Accordingly, the efficiency of heat transfer to the rear layer can be markedly enhanced.
• Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (10)

1. An ultrasonic probe, comprising:

a rear layer; and

a heat sink provided in the rear layer to dissipate heat.

2. The ultrasonic probe according toclaim 1, wherein the heat sink is coupled to a rear surface of the rear layer such that contact area therebetween are increased.

3. The ultrasonic probe according toclaim 2, wherein the heat sink includes a plurality of heat conductive protrusions on one surface thereof, the heat conductive protrusions being inserted into respective heat conductive depressions formed in the rear layer, each of the heat conductive depressions having a shape corresponding to the respective heat conductive protrusion.

4. The ultrasonic probe according toclaim 3, wherein each of the heat conductive protrusions has a bar shape.

5. The ultrasonic probe according toclaim 4, wherein each of the heat conductive protrusions has an inclined surface on an end thereof to form an acute end.

6. The ultrasonic probe according toclaim 4, wherein each of the heat conductive protrusions includes an insert hole, the insert hole penetrating from a distal end of the heat conductive protrusion to a proximal end thereof.

7. The ultrasonic probe according toclaim 6, wherein the insert hole has a conical shape.

8. The ultrasonic probe according toclaim 3, wherein each of the heat conductive protrusions has a conical shape.

9. The ultrasonic probe according toclaim 2, wherein the heat sink includes an insert part to be inserted toward a rear surface of the rear layer.

10. The ultrasonic probe according toclaim 9, wherein the insert part includes a coil-shaped wire.

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