JP2000115892A - Manufacture of ultrasonic wave vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the manufacture of an ultrasonic wave vibrator which is small-sized and easy to manufacture by providing a backing layer which causes particles to reflect irregularly the ultrasonic wave are uniformly formed with high density. SOLUTION: A molten backing material 7 with alumina powder blended thereto is filled in a back side space 6 and left standing for 1 to 2 hours. Then a high density layer 7a, a particle density changing layer 7b and a supernatant resin layer 7c where power particles hardly exist are formed sequentially from a bottom side of a frame member 5. Then the layers are slowly suctioned in the order of the resin layer 7c, and the particle density changing layer 7b to place the upper face of the particle density changing layer 7b at a position slightly higher than a notch 5b and the frame member 5 is cut of from the notch 5b. Thus, the frame member 5 is set to have a prescribed height, and the particle density changing layer 7b which was pooled at a position higher than the notch 5b overflows to the outside of the frame member 5 to form an ultrasonic wave absorbing layer 7d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ultrasonic vibrator having small and stable ultrasonic characteristics.

[0002]

2. Description of the Related Art In recent years, endoscopes have been widely used not only in the medical field but also in the industrial field. An ultrasonic endoscope in which an ultrasonic transducer for transmitting and receiving ultrasonic waves is provided at the distal end side of such an endoscope so that an ultrasonic image can be obtained has been put to practical use. The ultrasonic endoscope includes an ultrasonic observation device that performs signal processing to obtain an ultrasonic tomographic image, and a monitor that displays an ultrasonic image signal-processed by the ultrasonic observation device. An endoscope system is configured and used.

Further, ultrasonic pulses are repeatedly transmitted from the ultrasonic transducer into the living tissue, and echoes of the ultrasonic pulse reflected from the living tissue are received by the same or separate ultrasonic transducers. Diagnosis of disease by gradually shifting the direction in which ultrasonic pulses are transmitted and received, displaying echo information collected from multiple directions at the test site in the living body as an ultrasonic tomographic image of a two-dimensional visible image Various ultrasonic diagnostic apparatuses that can be used for such purposes have been proposed.

Further, in recent years, various three-dimensional scanning ultrasonic probes capable of obtaining a three-dimensional image so as to grasp the shape of a tumor or the like formed on a subject and measure the volume have been proposed.

In particular, the spread of ultrasonic examinations in the medical field has been remarkable and has become indispensable in obstetrics and gynecology, internal medicine, cardiology, surgery and the like. Therefore, it has been desired to reduce the size and stabilize the characteristics of an ultrasonic transducer used in an ultrasonic endoscope and the like.

For example, Japanese Unexamined Patent Publication No. Hei 7-159386 discloses a method of manufacturing an ultrasonic array probe in order to reduce the height of a pedestal and a backing material and to improve the vibration absorption of an ultrasonic vibrator by the backing material. In some cases, the pedestal is overlapped with the first pedestal and the second pedestal, the first pedestal and the printed circuit board are fixed, the second pedestal is placed via wax, and the first pedestal and the second pedestal are mounted. Is filled with a molten mixture (backing material), then separated into a high-density layer and a low-density layer by a centrifugation step, and the wax is dissolved in a removal step, and then the second pedestal and the low-density layer are removed. An ultrasonic array probe and a method of manufacturing the same are shown.

[0007]

However, in the ultrasonic probe and the method of manufacturing the same disclosed in Japanese Patent Application Laid-Open No. Hei 7-159386, after separating the second pedestal into a high-density layer and a low-density layer. In the step of removing from the first pedestal, the wax was dissolved to remove the second pedestal and the low density layer. In other words, since the second pedestal was removed after the wax was melted, it was difficult to obtain a uniform high-density layer by mixing the molten wax into the high-density layer. There was a problem that the sound wave characteristics varied. In addition, there is a problem that a manufacturing process is complicated and a man-hour is required, for example, a process of overlapping the first pedestal and the second pedestal and a process of removing the second pedestal are required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a method for manufacturing an ultrasonic vibrator which is small in size and easy to manufacture, having a uniform backing layer in which particles for irregularly reflecting ultrasonic waves have a high density. It is intended to be.

[0009]

According to a method of manufacturing an ultrasonic vibrator of the present invention, a step of forming a space into which an ultrasonic absorbing member is poured during a step of manufacturing an ultrasonic vibrator; A step of pouring an ultrasonic absorbing member in which particles that diffusely reflect sound waves are mixed, and sedimenting the particles mixed in the ultrasonic absorbing member, a high-density layer in which particles are sedimented at a high density in the space, A step of forming a particle density change layer in which the density of particles decreases as the distance from the bottom decreases, a resin layer that is a supernatant without particles, and removing a part of the resin layer and the particle density change layer formed in the space portion And cutting the height dimension of the frame member to a predetermined dimension, and further removing a part of the particle density change layer to set the backing material to a desired thickness dimension. .

According to this method of manufacturing an ultrasonic vibrator, a backing layer having a predetermined thickness is formed by a high-density layer in which particles for irregularly reflecting ultrasonic waves are high in a space and a particle-density changing layer. As a result, the ultrasonic characteristics are stabilized, and a part of the ultrasonic absorbing member that has flowed into the space is removed, and the thickness of the ultrasonic absorbing member is set in accordance with the height of the frame member. Can be reduced in size.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 10 show a first embodiment of the present invention.
FIG. 1 is a perspective view showing a piezoelectric element part and a frame member forming an ultrasonic transducer according to the embodiment, and FIG. 2 is a view showing a process of fixing the frame member to an acoustic matching layer to form a back space part. , FIG.
FIG. 4 is a view showing a step of pouring a backing material in a molten state into the back space part, FIG. 4 is a view showing a step of settling particles mixed in the backing material poured into the back space part, and FIG. FIG. 6 is a view showing a step of sucking a resin layer which is a supernatant, FIG. 6 is a view showing a state where suction of a backing material in a back space is completed, FIG. 7 is a view showing a step of cutting a frame member, and FIG. FIG. 9 is a diagram showing a state in which the ultrasonic absorbing member overflows by cutting the member, FIG. 9 is a diagram showing a step of cutting the acoustic matching layer to a predetermined size after curing the ultrasonic absorbing member, and FIG. It is a figure showing an ultrasonic transducer.

First, as shown in FIG. 1, a flat plate-shaped piezoelectric element 1 such as zirconate titanate or titanate is fixed to a metal base material 2 by using, for example, a double-sided tape or an adhesive. A piezoelectric element portion 4 laminated on an acoustic matching layer (hereinafter, also referred to as a matching layer) 3 made of glass, polyimide resin, epoxy resin member or the like, and a square hole 5a larger than the outer peripheral shape of the piezoelectric element 1; Then, as a frame member height setting means, a thin-walled frame member 5 having a substantially V-shaped notch 5b and having good shearability is prepared. The notch 5b is formed at a position separated from the lower end surface 5c of the frame member 5 by a predetermined distance (h). The piezoelectric element 1 is divided into an array, and each element is wired by a wiring member (not shown).

Hereinafter, the manufacturing process of the ultrasonic vibrator will be described. First, as shown in FIG.
Is bonded and fixed to the surface of the matching layer 3 constituting the piezoelectric element section 4 with an adhesive. As a result, the matching layer 3 of the base member 2 and the square hole 5a of the frame member 5 form a back space portion 6, which is a space portion into which an ultrasonic absorbing member to be described later flows, on the back side of the piezoelectric element 1. . At this time, a gap is formed between the outer peripheral surface of the piezoelectric element 1 and the inner peripheral surface of the square hole 5a as shown in the figure.

Next, as shown in FIG.
Then, a backing material 7 in a liquid state in which, for example, alumina powder is mixed as particles that diffusely reflect ultrasonic waves into an epoxy resin having a high ultrasonic attenuation effect is poured. Then, in a state where the backing material 7 is stored in the back space portion 6, the backing material 7 is left at a temperature of 60 ° C. to 70 ° C. where the viscosity is reduced for 1 hour to 2 hours. Then, during this time, the particles of the powder mixed in the epoxy resin stored in the back space 6 gradually settle.

Then, as shown in FIG. 4, the backing material 7 is arranged such that the powder particles settle down in order from the bottom side of the frame member 5 and the density of the high-density layer 7a with a large filling amount increases as the density of the powder particles moves away from the bottom. Therefore, a particle density change layer 7b, which decreases, and a resin layer 7c, which is a supernatant formed only of an epoxy resin having almost no powder particles, are formed.

Here, as shown in FIG. 5, a suction tip 8 constituting a suction tool is gently placed in the back space 6 into which the backing material 7 is poured, and the backing material 7 is formed.
The resin layer 7c and the particle density change layer 7b are gently sucked in this order. Then, further suction is performed, and as shown in FIG. 6, the particle density change layer 7 is located at a position slightly higher than the notch 5b.
When the upper surface of b is located, the suction portion tip 8 is pulled up to stop the suction of the backing material 7.

Next, as shown in FIG. 7, the frame member 5 is cut from the notch 5b. As a result, the frame member 5 is formed at a predetermined height. Then, as shown in FIG. 8, the upper side of the cutout 5b of the frame member 5 is cut, so that the particle density change layer 7 accumulated at a position higher than the cutout 5b.
b overflows to the outside of the frame member 5, and the high-density layer 7a and a part of the particle density change layer 7b remain in the back space 6 to become the ultrasonic absorption layer 7d. When the frame member 5 is cut, the backing material 7 that has overflowed and adhered to the outer surface of the frame member 5 or the surface of the matching layer 3 is removed by, for example, a cleaning tool (not shown) impregnated with alcohol, and then the back space is removed. In order to sufficiently cure the backing material 7 remaining in the portion 6, the backing material 7 is left at a temperature of 70 ° C to 80 ° C. Thereby, a backing layer 7e having a predetermined thickness is obtained.

When the backing material 7 is hardened to form the backing layer 7e as shown in FIG. 9, the base material is separated from the frame member 5 by a dicing saw around the matching layer 3 at a predetermined distance. Cutting groove 3 with depth reaching 2
a, and then, as shown in FIG.
From the matching layer 3. Then, an acoustic lens 9 made of a resin such as silicon or epoxy is fixed with an adhesive on the surface side of the matching layer 3 from which the base material 2 is removed, and the ultrasonic vibrator 1 is fixed.
0 is completed.

The backing material 7 is not limited to a material in which alumina powder is mixed in epoxy resin, but a material in which non-conductive ceramic powder is mixed in epoxy resin, tungsten powder having conductivity, ferrite, or the like. There is one mixed with powder or the like. When the particles have conductivity, the frame member is formed of a non-conductive member, and when the particles are non-conductive, the frame member is formed of a conductive member. When the frame member is formed of a conductive member, a circuit board provided with a copper foil on the front surface or the back surface may be used. In addition, a shielding effect can be obtained by forming the outer surface of the frame member to be conductive.

As described above, the ultrasonic absorbing member mixed with the particles for irregularly reflecting the ultrasonic wave is poured into the back space, and the particles are settled, and the resin layer and a part of the particle density change layer are separated from the back space. On the other hand, by removing the frame member from the cutout portion while removing, an ultrasonic absorbing layer having a predetermined thickness can be formed. This makes it possible to obtain a small-sized ultrasonic vibrator in which the thickness of the backing layer is small and whose characteristics are stable.

As shown in FIG. 11, the height of the frame member 5 is set to, for example, three to four times the dimension from the bottom surface to the notch 5b, so that the frame member 5 is notched.
When cutting from b, it becomes possible to cut easily.

As shown in FIG. 12, when the frame member 5 is cut from the notch 5b, a resin tape such as Teflon is applied to the outer peripheral surface of the frame member 5 and the surface of the matching layer 3 where the backing material 7 overflows. The member 11 is attached in advance as a cover. Thus, when the frame member 5 is cut, the overflowed particle density change layer 7b of the backing material 7 adheres to the surface of the tape member 11 as shown in FIG.
Therefore, by peeling off the tape member 11 from the outer peripheral surface of the frame member 5 and the matching layer 3, the overflowing particle density change layer 7b can be easily removed without wiping.

Incidentally, the tape member 11 is used as the cover.
The present invention is not limited to this, and a film may be formed by curing with a solder mask or the like.

FIG. 14 is a view showing another configuration of the frame member height setting means provided on the frame member according to the second embodiment of the present invention. As shown in the drawing, in the present embodiment, instead of forming the cutout portion 5b as a frame member height setting means in the frame member 5, a plurality of cutting holes 12 are formed in rows on the side surface of the frame member 5. ing. The openings of the through holes 12 are closed with a cover member 13 such as a tape to prevent the liquid backing material 7 flowing into the back space 6 through the through holes 12 from leaking.

Then, the backing material 7 is poured in a state where the through-holes 12 are closed by the cover member 13 and the particles are settled in the same manner as in the first embodiment.
3 is removed to open the through hole 12. Then, a part of the particle density change layer 7b of the backing material 7 and the resin layer 7c flow out through the through holes 12 to the outside. After that, the frame member 5 is cut from the through hole 12. Other configurations, operations and effects are the same as those of the first embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted. FIG.
FIG. 9 is a view showing a process in which a space forming member is arranged on a frame member according to a third embodiment of the present invention, and a space is formed by the space forming member and the frame member.

In this embodiment, the frame member 15 is formed in a predetermined size in advance. For this reason, the space forming member 1 is formed on the upper surface of the frame member 15 to form the back space 16 which is a space having a capacity into which the molten backing material 7 is poured.
7 is engaged.

The frame member 15 and the space forming member 1
The backing material 7 in a molten state is poured into the back space 16 formed by the backing material 7. Then, in a state where the backing material 7 is stored in the back space 6, the molten state is maintained.
The particles of the powder mixed in the epoxy resin are gradually settled by being left at a temperature of 60 ° C. for 1 hour to 2 hours.

Thereafter, if the high-density layer 7a, the particle density change layer 7b, and the resin layer 7c are formed in the back space 16 in order from the bottom side, the resin layer 7c,
After gently sucking in the order of the particle density change layer 7b, the space forming member 17 is gently removed from the frame member 15, and the particle density change layer 7b overflows to the outside of the frame member 15. After removing the overflowing backing material 7, the backing material 7 remaining in the back space 6 is sufficiently cured to form a backing layer 7e having a predetermined thickness. Other configurations and operations are the same as those of the first embodiment.

The frame member 15 and the space forming member 17
The fitting size is set so that the molten backing material 7 does not leak from the engaging portion of the backing material.

As described above, the two members of the frame member and the space forming member are used.
By forming a back space portion with one member and pouring a backing material into the back space portion to form a backing layer, the frame member is cut at an intermediate portion as in the first embodiment and the second embodiment. And a desired height dimension can be obtained. As a result, no cut surface is formed on the upper end surface of the frame member.

The space forming member 17 is connected to the frame member 15.
A tape member 18 wider than a predetermined width is attached to the outer peripheral surface of the frame member 15 to form a back space portion 16 which is a space portion having a capacity for pouring the molten backing material 7 instead of being engaged with the upper surface of the frame member 15. You may make it. Other configurations, operations and effects are the same as those of the third embodiment.

The present invention is not limited to only the above-described embodiments, but can be variously modified without departing from the gist of the invention.

[Appendix] According to the above-described embodiment of the present invention as described in detail above, the following configuration can be obtained.

(1) During the manufacturing process of the ultrasonic transducer, at least a step of forming a space into which the ultrasonic absorbing member is poured, and an ultrasonic absorbing device in which particles for irregularly reflecting ultrasonic waves are mixed. A step of pouring the member, and sedimenting the particles mixed in the ultrasonic absorbing member, a high-density layer in which the particles settled in the space at a high density, a particle density in which the particle density decreases as the distance from the bottom decreases A variable layer, a step of forming a supernatant resin layer free of particles, a step of removing a part of the resin layer and the particle density variable layer formed in the space, and setting a height dimension of the frame member to a predetermined value. And a step of setting a backing material to a desired thickness by further removing a part of the particle density change layer.

(2) The method of manufacturing an ultrasonic transducer according to claim 1, wherein said frame member is provided with frame member height dimension setting means for setting a height dimension of the frame member to a predetermined height.

(3) The method of manufacturing an ultrasonic transducer according to claim 1, wherein the height dimension of the frame member is set to a predetermined dimension in advance.

(4) The method of manufacturing an ultrasonic transducer according to claim 2, wherein said frame member height dimension setting means is a cutout formed in an outer surface of the frame member.

(5) The method of manufacturing an ultrasonic transducer according to claim 2, wherein said frame member height dimension setting means is a plurality of through holes arranged in a row on the frame member.

(6) The method of manufacturing an ultrasonic transducer according to appendix 3, further comprising a step of engaging and disposing a space forming member above the frame member to form a space.

(7) A step of forming a piezoelectric element portion by laminating a plate-shaped piezoelectric element on an acoustic matching layer fixed to a metal base material, and forming a piezoelectric element portion on the surface of the acoustic matching layer of the piezoelectric element portion. A step of fixing one end surface of the frame member to form a space into which the ultrasonic absorbing member is poured, and a step of pouring an ultrasonic absorber mixed with particles that diffusely reflect ultrasonic waves into this space,
A high-density layer in which the particles mixed in the ultrasonic absorbing member are settled, and the particles are settled in the space at a high density,
A step of forming a particle density change layer in which the density of particles decreases as the distance from the bottom decreases, a resin layer that is a supernatant without particles, and removing a part of the resin layer and the particle density change layer formed in the space portion And cutting the height dimension of the frame member to a predetermined dimension, further removing a part of the particle density change layer to set the backing material to a desired thickness dimension, and An ultrasonic vibrator having a step of curing to form a backing layer, a step of cutting the acoustic matching layer to a predetermined size, and a step of removing a base material fixed to the acoustic matching layer and fixing an acoustic lens Manufacturing method.

(8) A step of laminating a plate-shaped piezoelectric element on an acoustic matching layer fixed to a metal base material to form a piezoelectric element portion, and forming a piezoelectric element portion on the surface of the acoustic matching layer of the piezoelectric element portion. A step of fixing one end surface of the frame member, further engaging a space forming member above the frame member to form a space into which the ultrasonic absorbing member is poured, and particles that diffusely reflect ultrasonic waves into the space. Pouring an ultrasonic absorber mixed with
A high-density layer in which the particles mixed in the ultrasonic absorbing member are settled, and the particles are settled in the space at a high density,
A step of forming a particle density change layer in which the density of particles decreases as the distance from the bottom decreases, a resin layer that is a supernatant without particles, and removing a part of the resin layer and the particle density change layer formed in the space portion Removing the space forming member from the frame member, further removing a part of the particle density changing layer to set the backing material to a desired thickness, and curing the backing material to form the backing layer. Forming an acoustic matching layer, cutting the acoustic matching layer to a predetermined size, and removing the base material fixed to the acoustic matching layer and fixing the acoustic lens.

(9) A step of laminating a plate-shaped piezoelectric element on an acoustic matching layer fixed to a metal base material to form a piezoelectric element portion, and forming a piezoelectric element portion on the surface of the acoustic matching layer of the piezoelectric element portion. A step of fixing one end surface of the frame member, further applying a tape member on the upper portion of the frame member to form a space into which the ultrasonic absorbing member is poured, and mixing particles that diffusely reflect ultrasonic waves into the space. A step of pouring the ultrasonic absorber and sedimenting the particles mixed in the ultrasonic absorbing member, a high-density layer in which the particles sedimented in the space densely, the density of the particles decreases as the distance from the bottom increases A step of forming a resin layer that is a supernatant without particles, a step of removing a part of the resin layer and the particle density change layer formed in the space, and forming the tape member into a frame. Peel off from the component Setting a backing material to a desired thickness by further removing a part of the particle density change layer, curing the backing material to form a backing layer, and setting the acoustic matching layer to a predetermined size. A method for manufacturing an ultrasonic transducer, comprising: a cutting step; and a step of removing a base material fixed to the acoustic matching layer and fixing an acoustic lens.

[0043]

As described above, according to the present invention, there is provided a method of manufacturing an ultrasonic vibrator which is small in size and easy to manufacture, having a uniform backing layer in which particles for irregularly reflecting ultrasonic waves have a high density. be able to.

[Brief description of the drawings]

FIG. 1 to FIG. 10 relate to a first embodiment of the present invention, and FIG. 1 is a perspective view showing a piezoelectric element part and a frame member forming an ultrasonic transducer.

FIG. 2 is a view showing a step of fixing a frame member to an acoustic matching layer to form a back space portion.

FIG. 3 is a view showing a process of pouring a backing material in a molten state into a back space portion.

FIG. 4 is a view showing a process of settling particles mixed in a backing material poured into a back space portion.

FIG. 5 is a view showing a step of sucking a resin layer as a supernatant after particles settle.

FIG. 6 is a diagram showing a state in which suction of the backing material in the back space is completed.

FIG. 7 is a view showing a step of cutting the frame member.

FIG. 8 is a diagram showing a state in which the ultrasonic absorbing member overflows due to cutting of the frame member.

FIG. 9 is a view showing a step of cutting the acoustic matching layer to a predetermined size after curing the ultrasonic absorbing member.

FIG. 10 is a diagram showing an ultrasonic transducer.

FIG. 11 is a diagram showing another configuration example of the frame member.

FIG. 12 is a diagram showing a state where a tape member is arranged.

FIG. 13 is a view for explaining the operation of the tape member.

FIG. 14 is a diagram showing another configuration of the frame member height setting means provided on the frame member according to the second embodiment of the present invention.

FIG. 15 is a view showing a step of arranging a space forming member on a frame member according to the third embodiment of the present invention and forming a space with the space forming member and the frame member.

FIG. 16 is a diagram illustrating a process of arranging a tape member on a frame member according to an application example of the third embodiment of the present invention and forming a space with the tape member and the frame member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piezoelectric element 3 ... Acoustic matching layer 5 ... Frame member 5b ... Notch 6 ... Back space 7a ... High density layer 7b ... Particle density change layer

Claims (1)

[Claims] 1. A step of forming a space into which an ultrasonic absorbing member is poured during a manufacturing process of an ultrasonic vibrator, and pouring an ultrasonic absorbing member into which particles that diffusely reflect ultrasonic waves are mixed. A step, by sedimenting the particles mixed in the ultrasonic absorbing member, a high-density layer in which the particles sediment at a high density in the space,
Forming a particle density change layer in which the particle density decreases as the distance from the bottom increases, a resin layer that is a supernatant without particles, and removing a part of the resin layer and the particle density change layer formed in the space. And cutting the height dimension of the frame member to a predetermined dimension, and further removing a part of the particle density change layer to set the backing material to a desired thickness dimension. A method for manufacturing an ultrasonic vibrator characterized by the following.