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JP2007036642

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DESCRIPTION JP2007036642
In an ultrasonic probe having a plurality of transducer elements, ground lines can be connected
to each of the transducer elements without providing a common ground electrode to the plurality
of transducer elements. A 2D array transducer 14 is constituted by a plurality of transducer
elements 15. The backing 16 has a signal lead array and a ground lead array. A ground
connection structure is constructed between the adjacent vibrating elements 15 in the X
direction. The ground connection structure has a pair of side electrodes 34 facing each other.
The ground lead 26 is connected to the top electrode 30 through the side electrode 34. In the Y
direction, a ground connection structure can be provided for every other one of the plurality of
separation grooves 22, or a ground connection structure can be provided for each of the
separation grooves 22. Each vibration element can also be a laminated type. [Selected figure]
Figure 1
Ultrasonic probe and method of manufacturing the same
[0001]
The present invention relates to an ultrasonic probe which transmits and receives ultrasonic
waves by a plurality of vibration elements, and a method of manufacturing the same.
[0002]
Recently, an ultrasound probe equipped with a 2D array transducer has been put to practical use.
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In general, a 2D array transducer is composed of hundreds to thousands of transducer elements
arranged in a two-dimensional manner. There is also known a sparse array type transducer in
which a plurality of effective transducer elements are set in a distributed manner as a type of 2D
array transducer. Generally, a backing that scatters and absorbs ultrasonic waves emitted
backward is provided on the lower surface side (rear surface side) of the 2D array transducer. A
matching layer composed of one or more layers is provided on the top surface side of the 2D
array transducer. Various methods have been proposed to connect signal lines and ground lines
to the respective transducer elements constituting the 2D array transducer.
[0003]
Typically, the signal lead array is embedded in the backing. Each signal lead which constitutes it
passes through the backing and is connected to the lower electrode (signal electrode) of the
vibrating element. On the other hand, on the upper surface side of the plurality of transducer
elements, a common ground electrode made of a single copper foil or the like is provided so as to
cover the entire upper surface electrode (ground electrode). In this configuration, after forming
the common ground electrode on the plurality of transducer elements, the matching layer is
provided on the common ground electrode. Therefore, it is necessary to separately perform the
cutting of the vibrating member and the cutting of the matching layer. In the latter cutting, if the
whole of the matching layer is cut, the common ground electrode may be damaged, so that the
lower part of the matching layer is partially left. In this configuration, the acoustic characteristics
may be adversely affected due to partial coupling between adjacent matching elements. For
example, it is not possible to obtain a sufficiently spread sound pressure distribution for each
transducer (a decrease in directivity characteristics), and therefore a sufficient sound pressure
can not be obtained when the deflection angle of the ultrasonic beam is increased in electronic
sector scanning. And problems arise. In addition, acoustic crosstalk between the transducer
elements is also a problem.
[0004]
From the above background, there is a demand for connecting a ground line for each of the
plurality of transducer elements without providing a common ground electrode. Alternatively, a
structure for realizing individual connection of signal lines and ground lines to each transducer is
required.
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2
[0005]
In the ultrasonic probe shown in Patent Document 1, vertical electrodes shorting the upper
surface electrode and the lower surface electrode of each transducer element are shown. In the
ultrasonic probe, the common ground electrode is provided on the upper surface side of the
plurality of transducer elements, and the matching layer is not cut. In the ultrasonic probe shown
in Patent Document 2, a common ground electrode is provided, and a partial connection occurs
between a plurality of matching elements. In the ultrasonic probe shown in Patent Document 3,
the holding of each transducer and the electrical connection to each electrode are made using a
printed circuit board. In this configuration, the printed circuit board may restrain the vibration of
each vibrating element, and the production of the ultrasonic probe may be complicated. In the
ultrasonic probe shown in Patent Document 4, a plurality of signal lines and a plurality of ground
lines are provided in the backing. In addition, vertical electrodes are provided on the side
surfaces of the respective transducer elements. The lower end portion of the vertical electrode
does not enter into the backing but is bent in the horizontal direction, that is, it is wound around
the lower surface side of the vibrating element. A ground lead is connected to the wraparound
portion. In the manufacturing process of the ultrasonic probe, a plurality of blocks
(corresponding to the vibration element array) are positioned on the backing. Therefore, there is
a concern about the adverse effect on the electric field by the wraparound portion and the
complexity of the positioning of the plurality of blocks. Patent Documents 5 and 6 disclose
laminated or composited ultrasonic probes.
[0006]
JP 2001-309497 JP JP 2004-140761 JP JP 2001-309493 JP JP 2002-02759 JP JP 2004097791 JP JP 2004-097792 JP
[0007]
An object of the present invention is to improve the characteristics of an ultrasound probe.
[0008]
Another object of the present invention is to reduce acoustic crosstalk, improve directivity
characteristics, or enable formation of a good electric field in an ultrasound probe.
[0009]
Another object of the present invention is to reduce the manufacturing cost of an ultrasound
probe.
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[0010]
Another object of the present invention is to enable simultaneous fabrication of multiple
matching elements and multiple oscillating elements.
[0011]
(1) According to the present invention, a vibration unit having a plurality of vibration elements,
and a first lead array and a second lead array provided on the lower surface side of the vibration
unit and provided corresponding to the arrangement of the plurality of vibration elements And a
matching portion provided on the upper surface side of the vibrating portion and having a
plurality of matching elements provided corresponding to the arrangement of the plurality of
vibrating elements, each of the vibrating elements being a bottom electrode An upper surface
electrode and a side surface electrode, wherein in each of the vibration elements, a first lead
corresponding to the vibration element is electrically connected to the lower surface electrode,
and the upper surface electrode is interposed via the side electrode The second leads
corresponding to the vibrating elements are electrically connected, and the lower end portions of
the side electrodes of the vibrating elements enter the upper layer portion of the backing, and the
upper electrodes of the backing form the side electrodes of the vibrating elements. End is
electrically connected to the second lead corresponding to the vibrating element, characterized in
that.
[0012]
According to the above configuration, the first lead array and the second lead array are provided
in the backing, and using them, the signal line and the ground line are connected to each of the
transducer elements.
Preferably, the first lead array is a signal lead array and the second lead array is a ground lead
array, but the opposite correspondence may be considered.
Each vibrating element is provided with an upper surface electrode, a lower surface electrode,
and a side surface electrode.
When each vibration element is a laminated type, one or more internal electrodes are further
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provided.
A first lead is connected to the lower surface electrode in each of the transducer elements.
The second lead is connected to the top electrode through the side electrode.
Typically, each transducer element has four sides, of which one or more sides are provided with
side electrodes. The side electrode is preferably a planar electrode from the viewpoint of easiness
of manufacture, but it may be a form other than that, for example, a linear electrode. In order to
improve the electrical insulation and prevent the side electrode from adversely affecting the
electric field, it is desirable to form a side insulating layer between the vibrating element body
and the side electrode.
[0013]
In the above configuration, the lower end of the side electrode extends into the upper layer
portion of the backing, assuming that the stacking direction of the backing, the vibrating portion
and the alignment portion is the vertical direction (up and down direction). Electrical connection
between (the lower end portion) and (the upper end portion) of the second lead is achieved.
Therefore, the side electrode does not need to be in a special form, and the form can be
simplified, which facilitates the manufacture of the side electrode. For example, the side electrode
can be easily formed by pouring of the conductive material and cutting of the hardened
conductive material. Further, if the side electrodes are formed in a straight form in the vertical
direction, the influence on the electric field (disturbance of the electric field) formed in the
vibrator main body can be reduced. Since (the upper end of) the second lead can be positioned
substantially directly below the side electrode, the second lead is separated from the central
position (preferably, the first lead position) of the vibrating element. The second lead may be
configured as a linear conductive member, but is preferably configured as a plate-shaped
conductive member. If the thickness of the side electrode is reduced, the adverse effect on the
vibration in the vibrating element can be virtually ignored. Furthermore, an aspect in which the
periphery of the first lead is surrounded by the second lead can be adopted, in which case the
electrical shielding action can be enhanced.
[0014]
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Further, according to the above configuration, since it is possible to make an electrical
connection to the second lead individually for each vibration element, it is not necessary to
provide a common ground electrode widely spread in the horizontal direction. Therefore, it is
possible to cut the vibration part and the alignment part at once. That is, by forming the plurality
of separation grooves, separation of the plurality of transducer elements and separation of the
plurality of matching elements can be achieved simultaneously. However, the separation grooves
may be individually formed for each of the plurality of members, instead of collectively. Various
configurations can be adopted as the configuration of the matching unit. A plurality of matching
layers may be provided on the vibrating portion. Conventionally, when the common ground
electrode is provided, there is a problem that the ground distance of the ground line is increased
to easily pick up noise. However, according to the above configuration, such a problem can be
solved or improved. In the matching section, if the matching elements are completely separated
from each other, the acoustic crosstalk between the vibrating elements can be improved, and the
directivity angle of each vibrating element can be broadened. Therefore, sufficient sensitivity can
be obtained even when the deflection angle of the ultrasonic beam is increased.
[0015]
(2) Desirably, at least one side electrode pair is connected to each of the second leads, and the
side electrode pair is constituted by two side electrodes facing each other between two adjacent
transducer elements. A separation groove exists between two side electrodes constituting a side
electrode pair, and the separation groove is generally filled with a filling material which does not
adversely affect ultrasonic vibration, but it is used as an air layer It is also good. Preferably, each
of the second leads has a flat plate shape, and a side electrode pair row composed of a plurality
of side electrode pairs is connected to each of the second leads. If a plurality of side electrode
pairs can be connected to one second lead, the number of parts can be reduced.
[0016]
Preferably, each of the separation grooves is a groove formed by separating the plurality of
vibration elements by a plurality of separation grooves and penetrating from the alignment
portion to the upper layer portion of the backing. The bottom level of each separation groove
may be below or above the lowest level of each side electrode. In any case, it is desirable to
ensure that each side electrode is connected to the second lead. It is possible to have the bottom
level of each separation groove above the top of the backing, but in that case the separation
between the transducer elements is incomplete and acoustic crosstalk is likely to occur, so the
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bottom of the separation groove is The level is preferably set below the upper surface of the
backing (ie, in the upper portion of the backing).
[0017]
Desirably, an insulating means is provided to electrically insulate the side electrode and the lower
electrode in each of the vibration elements. Desirably, the lower end of the insulating means is in
the upper layer of the backing. According to this configuration, the insulation becomes more
reliable. The insulation means is preferably configured as an insulation gap or a side insulation
layer.
[0018]
Preferably, the first read array is composed of a plurality of first leads having the same
arrangement as the arrangement of the plurality of transducer elements. An electrode pad may
be provided on the upper end surface of each first lead that appears on the upper surface of the
backing.
[0019]
Preferably, the plurality of transducer elements are separated from each other by a plurality of
separation grooves aligned in the X direction and the Y direction, and side electrodes are formed
on at least one of two side surfaces facing the X direction in each transducer element. The second
lead array is composed of a plurality of second leads arranged at a predetermined pitch in the X
direction. Desirably, side electrodes are formed on one of two side surfaces facing in the X
direction in each of the vibration elements, and a plurality of side electrode pairs are aligned at a
predetermined pitch in the X direction in the vibrator portion, and each of the side electrode
pairs Is constituted by two side electrodes facing each other between the two transducer
elements adjacent in the X direction, and the predetermined pitch corresponds to twice the
separation groove pitch in the X direction. Desirably, side electrodes are formed on both of the
two side surfaces facing in the X direction in each of the vibrating elements, and a plurality of
side electrode pairs are aligned at a predetermined pitch in the X direction in the vibrator
portion, and each of the side electrode pairs Is constituted by two side electrodes facing each
other between the two transducer elements adjacent in the X direction, and the predetermined
pitch corresponds to the separation groove pitch in the X direction.
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[0020]
When side electrodes are formed on only one side of each vibrating element, a pair of side
electrodes can be made to face each other between two adjacent vibrating elements, and the pair
of side electrodes is used as a common second lead. It can connect. That is, the number of second
leads in the backing can be reduced. In the case where side electrodes are formed on both sides
of each vibrating element, symmetry of the electric field can be obtained in each vibrating
element.
[0021]
(3) The present invention is provided on a vibrating portion having a plurality of two-dimensional
array type vibrating elements mutually separated by a plurality of separation grooves, and
provided on the lower surface side of the vibrating portion, corresponding to the array of the
plurality of vibrating elements A signal lead array and a backing having a ground lead array, and
a matching section provided on the upper surface side of the vibrating section and having a
plurality of matching elements provided corresponding to the arrangement of the plurality of
vibrating elements. And each of the vibrating elements has a lower surface electrode, an upper
surface electrode, and a side electrode, and in each of the vibrating elements, a signal lead
corresponding to the vibrating element is electrically connected to the lower surface electrode; A
ground lead corresponding to the vibrating element is electrically connected to the upper surface
electrode through the side electrode, and a plurality of ground connection structures are
constructed in the vibrating portion, and the respective ground connections are provided.
Concrete has a side surface electrode pairs that face each other with a separation groove, said
side electrode pair is electrically connected to a common ground lead to them, characterized in
that.
[0022]
The ground connection structure has side electrode pairs and desirably has a symmetrical
structure with respect to the vertical center line of the separation groove.
Since connection to a common ground lead can be made in units of side electrode pairs, the
structure and manufacturing process can be streamlined and simplified. In addition, since the
side electrode pairs have the same polarity, electrical wraparound can be prevented and noise
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can be reduced.
[0023]
Desirably, upper ends of a plurality of signal leads are provided immediately below a plurality of
lower surface electrodes in the vibrator portion, and upper ends of a plurality of ground leads are
provided immediately below a plurality of ground connection structures in the vibrator portion.
Be Desirably, the lower end of the side electrode pair in each of the ground connection structures
is vertically embedded in the upper layer of the backing.
[0024]
Preferably, an insulation gap is formed between the side electrode and the lower electrode in
each of the vibrating elements. Preferably, a side insulating layer is formed between the side
electrode and the vibrating element main body in each of the vibrating elements. The electrical
insulation can be improved by the side insulating layer, and the dielectric constant can be
appropriately set to effectively prevent or reduce the distortion of the electric field in the
vibrating element body caused by the presence of the side electrode. .
[0025]
(4) The present invention is provided on a vibrating portion having a plurality of two-dimensional
array type vibrating elements mutually separated by a plurality of separation grooves, and
provided on the lower surface side of the vibrating portion, corresponding to the array of the
plurality of vibrating elements A signal lead array and a backing having a ground lead array, and
a matching section provided on the upper surface side of the vibrating section and having a
plurality of matching elements provided corresponding to the arrangement of the plurality of
vibrating elements. And each of the vibration elements includes a signal lower surface electrode,
a ground upper surface electrode, a signal internal electrode, a ground internal electrode, a signal
side electrode and a ground side electrode, and in each of the vibration elements, the signal lower
surface electrode is A signal lead corresponding to the vibrating element is electrically connected,
and the signal inner electrode is connected to the signal lower electrode and the signal side
electrode. A signal lead corresponding to the vibration element is electrically connected, and a
ground lead corresponding to the vibration element is electrically connected to the ground upper
surface electrode and the ground internal electrode via the ground side surface electrode. A
plurality of signal connection structures are constructed in the vibration unit, each signal
connection structure includes a signal side electrode pair facing each other via a separation
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groove, and a plurality of ground connection structures are constructed in the vibration unit.
Each of the ground connection structures has a pair of ground side electrode facing each other
through a separation groove.
[0026]
According to the above configuration, each vibration element can function as a stacked vibration
element.
The signal connection structure and the ground connection structure desirably have a
symmetrical structure with respect to the vertical center line of the separation groove. Generally,
by repeating the steps of groove formation and groove filling, it is possible to form a horizontal
multilayer structure having left-right symmetry.
[0027]
(5) The present invention comprises the steps of: laminating a diaphragm on a backing on which
a signal lead array and a ground lead array are embedded, thereby manufacturing a laminate;
Forming a plurality of base grooves penetrating into the upper layer portion and introducing a
conductive member into them; and after introducing the conductive member, a plurality of
members penetrating the upper layer portion of the backing from above with respect to the
laminate Forming a plurality of vibration elements having side electrodes as residual conductive
members, thereby forming a separation groove of the lower surface electrode of each of the
vibration elements to a signal lead corresponding to the vibration elements. It is electrically
connected, and the upper surface electrode of each of the vibrating elements is electrically
connected to the ground lead corresponding to the vibrating element through the side electrode.
That.
[0028]
The present invention comprises the steps of laminating a diaphragm on a backing on which a
signal lead array and a ground lead array are embedded, thereby manufacturing a first laminate,
and the backing from above with respect to the first laminate. Forming a plurality of base
grooves penetrating into the upper layer of the upper layer, introducing a conductive member
into them, and laminating a matching plate on the first laminate into which the conductive
member is introduced; Forming a body, forming a plurality of separation grooves penetrating
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from above the second laminate to the upper layer portion of the backing, thereby forming a
plurality of vibrations having side electrodes as a residual conductive member Manufacturing the
element, the lower surface electrode of each of the vibration elements is electrically connected to
the signal lead corresponding to the vibration element, and the upper surface electrode of each
of the vibration elements is through the side electrode Electrically connected to the ground lead
corresponding to the vibrating elements Te, characterized in that.
Desirably, the groove width of each separation groove is narrower than the groove width of each
base groove.
[0029]
The present invention comprises the steps of laminating a diaphragm on a backing on which a
signal lead array and a ground lead array are embedded, thereby manufacturing a laminate, and
from the upper to the upper layer portion of the backing with respect to the laminate. Forming a
plurality of penetrating first base grooves, introducing an insulating member into them, and
introducing the insulating member, and penetrating the laminate from above to the upper layer
portion of the backing after introducing the insulating member; Forming a second base groove,
thereby leaving a side insulating layer on the inner surface of each second base groove, and
further introducing a conductive member into the plurality of second base grooves; After the
introduction of the member, a plurality of separation grooves are formed in the laminate to
penetrate into the upper layer portion of the backing from above, thereby forming a side surface
electrode as a side surface insulating layer and a residual conductive member Manufacturing the
plurality of vibration elements, wherein the lower surface electrode of each vibration element is
electrically connected to the signal lead corresponding to the vibration element, and the upper
surface electrode of each vibration element is connected via the side electrode And electrically
connected to the ground lead corresponding to the vibration element.
[0030]
Desirably, the groove width of each second foundation groove is narrower than the groove width
of each first foundation groove, and the groove width of each separation groove is narrower than
the groove width of each second foundation groove. .
[0031]
As described above, according to the present invention, it is possible to appropriately connect the
signal line and the ground line to each of the transducer elements, and to provide an ultrasonic
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probe having good characteristics.
Further, according to the present invention, the manufacturing cost of the ultrasonic probe can
be reduced.
[0032]
Hereinafter, preferred embodiments of the present invention will be described based on the
drawings.
[0033]
A perspective view of a transducer assembly (internal unit) 10 is shown in FIG.
The transducer assembly 10 is disposed in an ultrasound probe case not shown.
The ultrasound probe according to the present embodiment is connected to the ultrasound
diagnostic apparatus main body (not shown) via a cable. An ultrasonic diagnostic apparatus is an
apparatus used in the medical field to form an ultrasonic image based on echo data obtained by
transmission and reception of ultrasonic waves to a living body. The transducer assembly 10
according to this embodiment has a 2D array transducer 14 as described in detail later. By
applying a two-dimensional electronic scan to the 2D array transducer 14, an ultrasonic beam
can be two-dimensionally scanned, whereby a three-dimensional echo data acquisition space can
be formed in the living body. . The present invention is also applicable to an ultrasound probe or
the like provided with a 1.5D array transducer having a plurality of two-dimensionally arranged
transducer elements, in addition to the ultrasound probe having a 2D array transducer. it can. As
the electronic scanning method, electronic sector scanning, electronic linear scanning, and the
like are known.
[0034]
In FIG. 1, the transducer assembly 10 includes a 2D array transducer 14, a backing 16 and a
matching layer 18. As described above, the 2D array transducer 14 functions as a vibration unit
that transmits and receives ultrasonic waves to form an ultrasonic beam. A backing 16 for
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absorbing and attenuating ultrasonic waves is provided on the lower side or back side of the 2D
array transducer 14, and a matching layer for matching acoustic impedance on the upper side or
radiation side of the 2D array transducer 14. 18 are provided. The matching layer 18 functions
as a matching unit. The matching unit may be constituted by a plurality of matching layers.
[0035]
In FIG. 1, when the radiation direction of ultrasonic waves is defined as the Z direction (vertical
direction), the X direction and the Y direction are each defined as the horizontal direction.
[0036]
The above-described 2D array transducer 14 is constituted by, for example, hundreds or
thousands of transducer elements 15 aligned in the X direction and the Y direction.
The vibrating element 15 has side electrodes 34 formed on the side surfaces of the vibrating
element body as described below. Specifically, the vibrating element 15 is formed of PZT or a
piezoelectric material 29 made of a composite material, an upper surface electrode (ground
electrode) 30 formed on the upper surface of the piezoelectric material 29, and a lower surface
formed on the lower surface of the piezoelectric material 29. An electrode (signal electrode) 32
and a side electrode 34 formed on the side surface of the piezoelectric material 29 are provided.
Each of the electrodes 30, 32, 34 constitutes a thin film electrode layer.
[0037]
In the embodiment shown in FIG. 1, the side electrode 34 is formed on only one side surface of
the two side surfaces facing the X direction in the vibration element main body. The side
electrode 34 is a planar electrode that extends over the entire side as shown, and the lower end
thereof is in the backing 16 as described in detail later. Among the four side surfaces of the
vibrating element 15, for example, side electrodes may be formed on each of the two side
surfaces facing in the X direction as described later, or all of the four side surfaces are side
electrodes. It is also possible to form. An insulating gap is formed between the lower end of the
side electrode 34 and the lower electrode 32, which will be described later.
[0038]
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13
The backing 16 is constituted by a backing material 28 and signal lead arrays and ground lead
arrays embedded therein. They are connected to an FPC (flexible printed circuit) substrate
provided on the lower surface side of the backing 16. The backing material is composed of an
epoxy resin as a base material, to which a filler such as boron nitride or tungsten is added. Of
course, various materials are known as the backing material 28. The signal lead array is
constituted by a plurality of signal leads 24 two-dimensionally arranged as shown. The
arrangement of the plurality of signal leads 24 is the same as the arrangement of the plurality of
transducer elements 15, and one signal lead 24 is provided for each transducer element. The
upper end portion of the signal lead 24 is connected to the central portion of the lower surface
electrode 32 in the corresponding vibrating element 15. In FIG. 1, the upper end surface of the
signal lead that appears on the upper surface of the backing 16 is represented by reference
numeral 24A. An electrode pad or the like may be provided on the upper end surface 24A. The
backing 16 and the 2D array transducer 14 are positioned relative to each other so that the
upper end of each signal lead 24 coincides with the center of the lower surface electrode 32 in
each transducer element. In the present embodiment, each signal lead 24 is constituted by a
linear conductive member.
[0039]
The above ground lead array is constituted by a plurality of ground leads 26 in the present
embodiment. The plurality of ground leads 26 are arranged at predetermined intervals in the X
direction as illustrated. The interval is twice the inter-vibrator pitch (i.e. twice the separation
groove pitch described later) as described later. Each ground lead 26 is configured as a plate-like
conductive member extended in the Y direction in the configuration example shown in FIG. That
is, each ground lead 26 is configured as a member that spreads in the YZ plane. As illustrated, in
the X direction, a plurality of vibration elements (a plurality of separation grooves) exist, but a
ground lead 26 is provided immediately below every other separation groove. The side electrode
34 of each vibrating element 15 is electrically connected to the ground lead 24 corresponding to
the vibrating element 15. Specifically, the lower end of the side electrode 34 is physically
coupled to the upper end of the ground lead 24.
[0040]
As will be described later, the ground connection structure is constructed for every other
separation groove 22 in the X direction, that is, the side electrode pair is constructed, and each
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14
side electrode pair is connected to the common ground lead 26 . Focusing on the Y direction, a
plurality of ground connection structures are aligned, that is, a side electrode pair row consisting
of a plurality of side electrode pairs is connected to the common ground lead 26. Such a
configuration has an advantage that the structure of the backing 16 can be simplified by
reducing the number of parts.
[0041]
The matching layer 18 is formed of a plurality of matching elements 19 having the same
arrangement as the plurality of vibrating elements 15. By forming the plurality of separation
grooves 20, 22 aligned in the X direction and the Y direction in a matrix on the laminated portion
including the alignment portion and the vibration portion, the alignment portion and the
vibration portion can be subdivided. . As a result, there is an advantage that the plurality of
matching elements 19 constituting the matching layer 18 and the plurality of transducer
elements 15 constituting the 2D array transducer 14 can be separately formed separately. That
is, the common ground electrode is not provided between the 2D array vibrator 14 and the
matching layer 18 as in the prior art, and the matching part and the vibrating part are formed by
cutting and forming the plurality of separation grooves 20 and 22 in the Z direction. There is an
advantage that it can be manufactured collectively. Since it is possible to completely separate the
plurality of matching elements from each other, it is possible to significantly reduce the acoustic
crosstalk between the vibrating elements and to narrow the directivity angle by partially
connecting the adjacent matching elements. It becomes possible to eliminate the problem of the
problem and to widen the directivity angle for each transducer. This makes it possible to obtain
sufficient sensitivity even when, for example, the deflection angle of the ultrasonic beam is
increased in electronic sector scanning. In addition, since no acoustically heavy member is placed
on the upper surface side of the 2D array transducer 14, there is also an advantage that vibration
of each transducer in the 2D array transducer 14 can be favorably performed. Furthermore,
when the common ground electrode as in the prior art is provided, the path length of the ground
line for each transducer is necessarily long, and as a result, the possibility of noise mixing is
increased. There is an advantage that ground lines can be individually formed for each of the
vibration elements to effectively reduce the problem of noise mixing. In addition, ground lines
can be formed for each vibration element 15, which is also advantageous in terms of electrical
crosstalk.
[0042]
Next, the structure of the 2D array transducer will be further described in detail with reference to
FIG.
04-05-2019
15
[0043]
Two vibrating elements 15A and 15B are shown in FIG. 2 as enlarged views.
FIG. 2 shows an X-Z cross section. As described above, each of the vibration elements 15A and
15B includes the piezoelectric material 29, the upper surface electrode 30, the lower surface
electrode 32, the side surface electrode 34, and the like. In the embodiment shown in FIGS. 1 and
2, the side electrodes 34 are formed on only one side of each of the transducer elements, and the
surfaces on which the side electrodes are formed in the X direction are alternately set. As a
result, in the X direction, a plurality of vibrating elements exist, but a ground connection
structure 40 is constructed between every other vibrating element among the plurality of
vibrating elements.
[0044]
That is, when focusing on the two adjacent vibrating elements 15A and 15B, the side electrode
34 is formed on the side surface of the vibrating element 15A on the vibrating element 15B side,
and similarly, the side surface of the vibrating element 15B on the vibrating element 15A side A
side electrode 34 is formed on the side wall. The two side electrodes 34 face each other via the
separation groove 22, and the two form a side electrode pair. Thus, the ground connection
structure 40 has a side electrode pair. Incidentally, reference numeral 42 indicates an interelement structure in which the side surfaces on which the side electrodes are not formed are
opposed to each other between the adjacent vibration elements. As described above, such a
ground connection structure 40 and the normal structure 42 are alternately set in the X
direction. The ground leads 26 are disposed only at the positions where the ground connection
structures 40 exist. In each of the vibrating elements 15A and 15B, the upper end 34a of the side
electrode 34 is coupled to the end of the upper surface electrode 30. Further, the lower end
portion of the side electrode 34 is electrically insulated from the lower surface electrode 32 by
the insulating gap 36, and the lower end 34 b is connected to the upper end portion of the
ground lead 26. Specifically, as shown in FIG. 2, the lower end portions of the pair of side
electrodes and the lower end portion of the separation groove 22 enter the upper end portion of
the ground lead 26.
[0045]
04-05-2019
16
That is, the lower end of each side electrode 34 is in the upper layer of the backing, and the
lower end of the separation groove 22 is in the upper layer of the backing. Furthermore, the
lower part of the insulation gap 36 also extends into the backing. In the example shown in FIG. 2,
the bottom level of the separation groove 22 is set lower than the level of the lower end 34b of
each side electrode 34, but it is possible to reverse their positional relationship. In any case, it is
desirable that the side electrodes 34 be reliably connected to the ground lead 26. Since the
insulating gap 36 partially penetrates into the backing, that is, the insulating gap 36 exists with a
constant width in the vertical direction with respect to the lower surface electrode 32, the
electricity between the side electrode 34 and the lower surface electrode 32 It has the advantage
of being able to ensure a certain degree of insulation. The insulating gap 36 is formed by filling
an insulating adhesive or the like as described later.
[0046]
As described above, in the X direction, the ground connection structure 40 is constructed around
every other separation groove 22 in the plurality of separation grooves 22. The ground
connection structure 40 has a left-right symmetrical structure in the X direction with reference
to the vertical center line in the separation groove 22. Due to this symmetry, there is an
advantage that the ground connection structure 40 can be easily formed by repeating the
process of groove formation and groove filling as described later. The lower ends of the two side
electrodes in the side electrode pair in an adjacent relationship are separated from each other in
the configuration example shown in FIG. 2, but they may be connected to each other. It is
possible to construct a desired ground connection structure by appropriately setting the depth of
each side electrode 34 and the depth of each separation groove 22.
[0047]
According to the embodiment shown in FIGS. 1 and 2, the lower end of the side electrode 34 in
each vibrating element 15 is inserted into the upper layer of the backing 16, and the lower end
of the side electrode 34 and the ground lead in the upper layer thereof. The electrical connection
with the upper end of 26 is advantageous in that a reliable connection of the ground can be
achieved. In addition, since the side electrodes 34 can be formed as a simple planar thin film
layer, there is an advantage that a pair of side electrodes can be collectively formed by a simple
manufacturing process as described later. In addition, since each side electrode has a straight
form extending in the vertical direction, it is not necessary to form a bend as in the prior art, so
that the manufacturing process can be simplified in that sense, and a special side electrode
04-05-2019
17
structure There is an advantage that it is possible to effectively prevent the problem such as the
disturbance of the electric field inside the vibrating element, which occurs when adopting. In the
present embodiment, since the pair of side electrodes facing each other is connected to the
common ground lead, there is an advantage that the number of parts can be reduced. As
described above, since the ground line can be formed by a short path for each of the vibration
elements 15, the problem of noise mixing can be effectively reduced. In addition, since the side
electrode 34 is configured as a conductor with good thermal conductivity, the heat generated
inside the vibrating element 15 can be effectively diffused to reduce the problem of thermal
concentration, which causes a clinical problem. There is an advantage that the ultrasonic probe
surface temperature can be reduced.
[0048]
In the embodiment shown in FIGS. 1 and 2, each separation groove 20, 22 is filled with a filling
material that is less likely to cause acoustic crosstalk. The stuffing also partially penetrates into
the upper layer of the backing 16. As shown in detail of the ground connection structure 40 in
FIG. 2, when focusing on the relationship between the 2D array transducer 14 and the backing
16, a plurality of anchor members project downward from the 2D array transducer 14 Is tightly
inserted in the upper layer portion of the backing 16 so that the mechanical connection between
the 2D array transducer 14 and the backing 16 can be made tight. This has the advantage that
the vibration characteristics can be improved.
[0049]
In the embodiment described above, the side electrode 34 is configured as a planar electrode, but
in some cases, it may be configured as a linear electrode. In addition, as will be described later, if
side electrodes are formed on each of the two side surfaces facing in the X direction in each
vibration element, there is also an advantage that the symmetry in the X direction can be
improved and the vibration characteristics can be improved.
[0050]
In this embodiment, since a plurality of plate-like ground leads are arranged at a predetermined
interval in the backing 16, there is also an advantage that the shielding performance in the
backing 16 can be improved.
04-05-2019
18
[0051]
Next, a method of manufacturing the vibrator assembly 10 according to the embodiment shown
in FIGS. 1 and 2 will be described using FIGS. 3 to 8. First, as shown in FIG. 3, the piezoelectric
plate 50 and the backing 16 Prepared.
The piezoelectric plate 50 is formed by subjecting a flat plate-like piezoelectric material 51 to
predetermined processing.
[0052]
Specifically, the upper and lower surfaces of the piezoelectric material 51 are polished, and on
the lower surface, a plurality of grooves 56 are formed with a pitch twice the pitch between the
transducer elements. Each groove 56 is a groove extending in the Y direction. After the formation
of the plurality of grooves 56, gold or the like is vapor-deposited on the lower surface of the
piezoelectric material 51. The deposited layer is indicated by reference numeral 54. Gold or the
like is vapor-deposited on the top surface of the piezoelectric material 51 at a necessary timing.
The deposited layer is represented by reference numeral 52. The formation of the vapor
deposition layer 52 on the upper surface can also be performed at a later stage.
[0053]
On the other hand, the upper surface of the backing 16 is polished, and thereafter a plurality of
grooves 62 are also formed on the backing 16 with a pitch twice the pitch between the
transducer elements. Each groove 62 is a groove extending in the Y direction. And gold etc. are
vapor-deposited with respect to the upper surface of the backing 16, and the vapor deposition
layer 60 is formed of this.
[0054]
The plurality of grooves 56 formed in the piezoelectric plate 50 and the plurality of grooves 62
formed in the upper surface of the backing 16 are for forming a plurality of insulating gaps. Due
to the deposition process on the lower surface of the piezoelectric plate 50 and the upper surface
04-05-2019
19
of the backing 16, deposition portions 58 and 66 are also generated inside the respective
grooves 56 and 62. Although the deposited portions 58 and 66 are essentially unnecessary, if
the deposited portions 58 and 56 are not electrically connected to the deposited layers 54 and
60, respectively, such deposited portions 58 and 66 are present. There is no problem even if
However, by forming the grooves 56 and 62 after forming the vapor deposited layers 54 and 60,
it is possible to prevent such vapor deposited portions 58 and 66 from being produced.
[0055]
Next, as shown in FIG. 4, the piezoelectric plate 50 and the backing 16 are bonded using an
insulating adhesive. The insulating adhesive is filled in the groove space 72 formed by the
grooves 56 and 62 described above. The reference numeral 74 indicates the insulating material
filled in each groove space 72. Incidentally, in FIG. 4, the two vapor deposition layers 54 and 60
described above are combined and shown as one electrode layer. If the two deposited layers are
completely in close contact with each other, the problem of electrical connection failure does not
occur. If necessary, an insulating adhesive may be applied between the two members to enhance
the electrical contact, and then the contact portion of each deposited layer 54, 60 may be
exposed. D1 in FIG. 4 represents the pitch between the transducer elements, and for example, D1
is 0.3 mm. D2 indicates the pitch between the lead frames 26, and the pitch is twice the abovementioned D1.
[0056]
Next, as shown in FIG. 5, a plurality of base grooves 80 are formed with an element-to-element
pitch or pitch D2 twice as high from the top of the bonded laminate. Each base groove 80 is a
groove extending in the Y direction. The depth of each base groove 80 defines the depth range of
the side electrode layer to be formed later. The formation of each base groove 80 cuts the central
portion of each insulating material 74 and also cuts the piezoelectric plate. Furthermore, the
upper end of the ground lead is also partially cut away. The vapor deposition layer 52 shown in
FIG. 3 is divided into a plurality of electrode layers 52A by the formation of a plurality of base
grooves 80. Incidentally, the flat portion of the deposition layer on the lower surface side of the
piezoelectric plate and the flat portion (reference numeral 54A) of the deposition layer on the
upper surface of the backing are preserved as they are at this stage. The formation of each base
groove 80 results in the insulating material 74 being split into two resulting in a pair of
insulation gaps 36 for each base groove 80. Incidentally, reference numerals 58 a and 66 a
indicate fragment elements in the vapor deposition layer portion divided by the formation of the
base groove 80. They are essentially nonfunctional.
04-05-2019
20
[0057]
Next, as shown in FIG. 6, the conductive members (conductive resin) are filled into the plurality
of base grooves 80 formed as described above, and the base members are cured. Then, as shown
in FIG. 7, the aligning plate 86 is adhered to the upper surface side of the laminate 84 composed
of the piezoelectric plate and the backing.
[0058]
Next, as shown in FIG. 8, a plurality of separation grooves 22 are formed between the respective
transducer elements. Specifically, a plurality of separation grooves 22 extending from the upper
side to the upper layer portion of the backing 16 are formed on the entire laminate including the
alignment plate 86. Also around that, a plurality of separation grooves extending in the Y
direction are also formed. As a result, the plurality of matching elements 19 are separately
formed in the matching layer 18, and the plurality of vibrating elements 15 are separately
formed also in the vibrating portion, whereby the 2D array vibrator 14 is configured.
[0059]
Each separation groove 22 reaches a position deeper than each base groove 80 described with
reference to FIG. 5 (the center position of both is the same, but the width of each separation
groove 22 is smaller), As a result, the conductive member 82 described with reference to FIG. 6 is
divided into two parts by the separation groove 22 penetrating the central part thereof, and each
constitutes the side electrode 34. That is, the side electrodes 34 remain on both sides of the
above-described base groove. Therefore, the formation of the separation groove 22 corresponds
to the formation of the matching element division, the vibration element division, and the side
electrode pair. Further, the formation of each separation groove 22 constitutes an upper surface
electrode 30 and a lower surface electrode 32 for each vibration element. A stuffing material is
filled in each separation groove 22 (20).
[0060]
04-05-2019
21
In the above-described embodiment, only by forming one separation groove 22, a plurality of
ground electrode structures 40 aligned in the Y direction can be constructed. That is, a plurality
of side electrode pairs arranged in the Y direction can be formed at one time. The side electrode
pairs form a side electrode pair row, and the side electrode pair row is collectively connected to
the common ground lead 26. Ground leads 26 are respectively positioned immediately below
each side electrode pair, and each side electrode pair and the ground lead 26 are in a
substantially linear relationship in the vertical direction. On the other hand, the signal lead 24 is
provided directly below the central portion of each transducer, that is, the upper end of each
signal lead 24 is connected to the central portion of the lower electrode 32 of each transducer.
[0061]
Next, a second embodiment of a vibrator assembly will be described with reference to FIGS. The
same components as those in the first embodiment shown in FIGS. 1 to 8 are denoted by the
same reference numerals, and the description thereof will be omitted.
[0062]
In FIG. 9, the transducer assembly 100 includes a 2D array transducer 102, a backing 16
provided on the lower surface side of the 2D array transducer 102, and a matching layer 18
provided on the upper surface side of the 2D array transducer 102. have. The 2D array
transducer 102 is composed of a plurality of stacked vibration elements 104 aligned in the X
direction and the Y direction. The laminated vibration element 104 will be described in detail
below.
[0063]
The laminated vibration element 104 has a plurality of vibration layers 106. The vibration layers
106 are stacked in the Z direction. An upper surface electrode 108 is provided on the upper
surface of the vibrating element 104, and a lower surface electrode 110 is provided on the lower
surface of the vibrating element 104. Further, internal electrodes 112 and 113 are provided
between the adjacent vibration layers 106. The upper surface electrode 108 and the internal
electrode 113 function as a ground electrode, and the lower surface electrode 110 and the
internal electrode 112 function as a signal electrode. In the vibrating element 104, the side
electrode 116 is formed on the side surface on one side in the X direction, and the side electrode
04-05-2019
22
120 is formed on the side surface on the other side. A side insulating layer 114 is formed
between the vibrating element body and the side electrode 116 in the vibrating element 104, and
a side insulating layer 120 is formed between the vibrating element body and the side electrode
122. The side insulating layer 114 is for securing the insulation between the side electrode 116
and the internal electrode 112. The upper end of the side electrode 116 is connected to one end
of the top electrode 108, and the lower end of the side electrode 116 is connected to one end of
the internal electrode 113. The side insulating layer 120 is for securing the insulation between
the side electrode 122 and the internal electrode 113. The upper end portion of the side
electrode 122 is connected to one end of the internal electrode 112, and the lower end of the
side electrode 122 is connected to the lower surface electrode 110.
[0064]
The side electrode 116 is an electrode for internal connection with respect to the ground, and the
side electrode 122 is an electrode for internal connection with respect to a signal. Further, side
electrodes 118 are formed facing the separation grooves 22 and adjacent to the side electrodes
116. The side electrode 118 is an electrode for external connection with respect to the ground.
The upper end of the side electrode 118 is connected to the upper electrode 108 together with
the side electrode 116, and the lower end of the side electrode 118 is inserted into the upper
layer of the backing 116 and connected to the upper end of the ground lead 26. An upper end
portion of the signal lead 24 is connected to the lower surface electrode 110.
[0065]
The signal lead 24 is connected to the lower surface electrode 110 and is further connected to
the internal electrode 112 through the side electrode 122 according to the connection
relationship as described above. The insulating property between the side electrode 122 and the
internal electrode 113 is secured by the side insulating layer 120. The ground lead 26 is
connected to the internal electrode 113 and the top electrode 108 via the side electrode 118 and
the side electrode 116. In this case, insulation between the side electrodes 116 and 118 and the
internal electrode 112 is ensured by the side electrode layer 114.
[0066]
Similarly to the embodiment shown in FIG. 1 and the like, also in the embodiment shown in FIG.
04-05-2019
23
9, the directions of the respective transducer elements are set alternately when focusing on the X
direction. That is, although a plurality of separation grooves 22 are formed in the X direction, the
ground connection structure 124 and the signal connection structure 126 are alternately set for
each separation groove. The ground connection structure 124 has a symmetrical structure with
respect to the vertical central axis of the separation groove 22, and the same applies to the signal
connection structure. However, in the signal connection structure, the second side electrode is
not provided. On the other hand, in the ground connection structure 124, the second side
electrode is used to electrically connect to the ground lead 26 beyond the side electrode 116. An
electrode 118 is provided.
[0067]
With such a configuration, it is possible to stack the respective transducer elements 104, and in
particular, it is possible to alternately connect the ground or the signal to the respective
electrodes 108, 112, 113, and 110 arranged in the vertical direction. Further, with regard to the
ground, it is possible to reliably make an electrical connection to the ground lead 26 by the side
electrode 118 penetrating in the vertical direction. Furthermore, since the side insulating layers
114 and 120 are provided for each vibration element, and they are configured as an insulating
layer that spreads like a plane on the side surface of the vibration element, it is possible to
sufficiently ensure the insulation required for the vibration element. It is possible to effectively
suppress the disturbance of the electric field generated inside the vibrating element due to the
formation of the side electrodes 116, 118, 122 in the direction perpendicular to the both side
surfaces. In addition, it is desirable that each side insulating layer 114, 120 be made of an
appropriate material so that such an effect can be achieved. Also in the embodiment shown in
FIG. 9, an insulation gap is provided. The insulating gap and the side insulating layer may be
integrally formed.
[0068]
Next, a method of manufacturing the transducer assembly 100 shown in FIG. 9 will be described
with reference to FIGS.
[0069]
First, as shown in FIG. 10, the laminated piezoelectric plate 130 and the backing 16 are prepared.
04-05-2019
24
Here, for the method of manufacturing the laminated piezoelectric plate 130, for example, the
contents described in Patent Documents 5 and 6 or the like serve as a reference. The stacked
piezoelectric plate 130 has three layers 132 made of a backing material stacked vertically, and
an internal electrode layer 134 is provided between each layer. In the laminated piezoelectric
plate 130, a plurality of groove structures are constructed in an alternating relationship from
above and below. After forming the first base groove with a large groove width, each groove
structure is filled with an insulating material and hardened therein, and then a second base
groove having a narrower width is formed, and a conductive member is formed therein. It can be
constructed by filling and curing.
[0070]
In FIG. 10, in each groove structure constructed from the upper side, a conductive member is
shown by reference numeral 142, and a side insulating layer made of an insulating material is
shown by reference numeral 114. The side insulating layer 114 has a plate-like form extending
in the Y direction. The same applies to the conductive material 142. Also in each groove
structure formed from the lower side in the laminated piezoelectric plate 130, the conductive
material is indicated by the reference numeral 146, and the side insulating layers formed on both
sides thereof are indicated by the reference numeral 120, as described above. There is.
[0071]
Further, a plurality of grooves 150 are formed on the lower surface side of the laminated
piezoelectric plate 130 with a pitch twice the pitch between the transducer elements, and a
plurality of grooves 154 are also formed on the upper surface of the backing 16. FIG. 10 shows a
state in which the upper surface side of the backing 16 has been subjected to the vapor
deposition process, and the vapor deposition process forms a vapor deposited layer 152 on the
upper surface of the backing 16 and a vapor deposited portion is formed inside each groove. Is
occurring.
[0072]
Next, as shown in FIG. 11, the lower surface and the upper surface of the laminated piezoelectric
plate 130 are subjected to a vapor deposition process. For example, a material such as gold is
04-05-2019
25
deposited. Thereby, the vapor deposition layer 158 is formed on the lower surface side, and the
vapor deposition layer 156 is formed on the upper surface side. They constitute an electrode
layer. Incidentally, a vapor deposition layer portion is generated in each groove 150 shown in
FIG. As described above, it is possible to exclude such a deposited layer portion generated in each
groove by appropriately changing the manufacturing process.
[0073]
Next, as shown in FIG. 12, the laminated piezoelectric plate 130 and the backing 16 are bonded
to each other using an insulating adhesive. Thus, the insulating material is filled in the groove
space formed by bonding of the upper and lower two grooves. It is represented by reference
numeral 158.
[0074]
Next, as shown in FIG. 13, an intermediate base groove 160 is formed at a fixed distance from
the upper side in the laminated body including the laminated piezoelectric plate 130 and the
backing 16. The fixed interval is twice the inter-vibrator pitch, and a base groove 160 is formed
for each ground lead. By the formation of each base groove 160, the insulating material is
divided into two from the middle thereof, thereby forming a pair of insulating gaps 162. At the
same time, the conductive member is also divided from the center to the left and right, and as a
result, side electrodes 164 for internal connection are formed.
[0075]
Then, as shown in FIG. 14, the conductive members 166 are filled in the respective base grooves
160. Incidentally, it is also possible to collectively form the side electrode 116 for internal
connection and the side electrode 118 for external connection (see FIG. 16) shown in FIG. 9 as
one side electrode by appropriately modifying the manufacturing process. is there.
[0076]
Next, as shown in FIG. 15, the alignment plate 170 is bonded to the upper surface side of the
04-05-2019
26
laminate 168 composed of the laminate type piezoelectric plate 130 and the backing 16. Then,
as shown in FIG. 16, a plurality of separation grooves 22 are formed with a pitch between the
transducer elements. The width of the plurality of grooves formed in a stepwise manner is set
smaller gradually. Each separation groove 22 is a groove extending in the Y direction. A plurality
of separation grooves orthogonal to it are formed before or after the formation of the plurality of
separation grooves 22. By forming the plurality of separation grooves 22, every other ground
connection structure 124 is constructed in the X direction, and the signal electrode structure
126 is constructed therebetween. In the ground connection structure 124, the formation of the
separation groove 22 causes the conductive member 166 described with reference to FIG. 14 to
be divided into two left and right from the center, and a pair of side electrodes 118 are formed as
remaining portions. It will be At the same time, the alignment plate 170 is divided into a plurality
of alignment elements 19 to form an alignment layer 18. Further, in the laminated piezoelectric
plate, the plurality of vibration elements are separated and formed by the formation of the
plurality of separation grooves, whereby the 2D array vibrator 102 is configured.
[0077]
In the signal electrode structure 126, the formation of the separation groove 22 divides the
conductive member 146 shown in FIG. 10 from the central portion into two, and as a result, a
pair of side electrodes 122 is formed as a remaining portion. .
[0078]
Therefore, the formation of the separation grooves 22 allows the pair of side electrodes 118 to
be collectively formed in the ground electrode 124 and the signal electrode structure 126 allows
the pair of side electrodes 122 to be collectively formed.
As described above, each separation groove 22 extends in the Y direction, and in fact, the
formation of the separation grooves 22 collectively forms a plurality of ground electrode
structures 124 or a plurality of signal electrode structures 126 aligned in the Y direction. It will
be Here, the plurality of side electrode pairs of the plurality of ground connection structures 124
aligned in the Y direction are electrically connected to the common ground lead.
[0079]
Next, a third embodiment of a transducer assembly will be described using FIGS. 17 to 25. FIG.
04-05-2019
27
The same components as those in the first embodiment shown in FIG. 1 and the second
embodiment shown in FIG. 9 will be assigned the same reference numerals and descriptions
thereof will be omitted.
[0080]
In FIG. 17, the transducer assembly 130 has a 2D array transducer 132, a backing 133 provided
on the lower surface side thereof, and a matching layer 18 provided on the upper surface side of
the 2D array transducer 132. .
[0081]
The 2D array transducer 132 is configured of a plurality of transducer elements 134 aligned in
the X direction and the Y direction.
Each vibrating element 134 has a vibrating element body 140 made of a piezoelectric material,
two side electrodes 144 formed on both side surfaces in the X direction, an upper surface
electrode 146 and a lower surface electrode 148. . A planar side insulating layer 142 is provided
between the vibrating element body 140 and the two side electrodes 144 so as to extend in the
vertical direction. The side insulating layers 142 can effectively suppress the problem of the
disturbance of the electric field generated by the side electrodes 144, and can significantly
improve the electrical insulation.
[0082]
As shown in FIG. 17, in the X direction, ground connection structures 135 are formed between
the respective transducer elements. Each ground connection structure 135 has a pair of side
electrodes 144 opposed to each other. The lower end portions of the side electrodes 144 enter
the upper layer portion of the backing 133 as in the above-described embodiments. However, in
this embodiment, the lower ends of the pair of side electrodes are connected to each other, and
the communication unit 150 is configured as illustrated. The connecting portion 150 is coupled
to the upper end of the ground lead 138. Incidentally, each signal lead 136 is connected to the
lower surface electrode 148 in the corresponding vibration element 134.
[0083]
04-05-2019
28
According to the embodiment shown in FIG. 17, since the side electrodes 144 are formed on each
of the two side surfaces facing in the X direction in each vibrating element 134, it is possible to
obtain symmetry of the electric field in the X direction, There is also an advantage that thermal
diffusion can be achieved by utilizing two aspects. In addition, since both ends in the X direction
are inserted into the backing 133 for each vibrating element to achieve a role as an anchor, it is
possible to make the mechanical coupling of each vibrating element to the backing 133 better. It
becomes. Of course, it is also possible to adopt a modified example in which the side electrodes
are formed on all of the four side surfaces of each vibration element 134.
[0084]
A method of manufacturing the transducer assembly 130 shown in FIG. 17 will be described with
reference to FIGS.
[0085]
First, as shown in FIG. 18, the piezoelectric plate 152 and the backing 133 are prepared.
Deposited layers 160 and 162 are formed on the upper and lower surfaces of the piezoelectric
plate 152 by deposition of gold or the like. In addition, a vapor deposition layer 164 is formed on
the top surface of the backing 133 by vapor deposition of gold or the like. Incidentally, the
polishing process is performed prior to the deposition process on each surface. This is similar to
the other embodiments.
[0086]
As shown in FIG. 19, the piezoelectric plate 152 and the backing 133 are adhered to each other
using a conductive adhesive or the like. In FIG. 19, the vapor deposition layers 162 and 164
shown in FIG. 18 are represented as one conductive layer.
[0087]
04-05-2019
29
Next, as shown in FIG. 20, a plurality of base grooves 166 are formed with a constant depth from
the upper side of the piezoelectric plate with a pitch between the transducer elements. Each base
groove 166 reaches the upper portion of the backing. The bottom surface of each base groove
166 is formed in such a manner that the upper end portion of the ground lead 138 is cut out.
[0088]
Next, as shown in FIG. 21, the insulating material 168 is filled in each of the base grooves 166
and hardened. Then, as shown in FIG. 22, a plurality of second base grooves 170 are formed to
penetrate the central portion of each of the insulating materials 168 filled in FIG. As a result, side
insulating layers 142 remain on both sides of each groove.
[0089]
Next, as shown in FIG. 23, the conductive members are filled in the respective second base
grooves 170, and the conductive members 174 are also provided on the top surface of the
laminate. Then, as shown in FIG. 24, after the conductive materials are cured, the alignment plate
176 is adhered to the upper surface side of the laminate 178. A layer of conductive adhesive may
be formed without providing the conductive member 174.
[0090]
Then, as shown in FIG. 25, a plurality of separation grooves 22 are formed with a pitch between
the transducer elements. A plurality of separation grooves extending in the X direction are also
formed along with it. The formation of the plurality of separation grooves 22 creates a pair of
side electrode layers 144 as a remaining portion where the conductive member filled in each
second base groove 170 is split into two from the central portion thereof. At the same time, the
matching plate is divided into a plurality of pieces, whereby a matching layer composed of a
plurality of matching elements is constructed. Similarly, a plurality of transducer elements are
formed, whereby a 2D array transducer 132 is constructed.
[0091]
04-05-2019
30
As shown in FIG. 25, the depths of the plurality of separation grooves 22 are set slightly
shallower than the depths of the plurality of second foundation grooves 170 described above,
whereby the lower side of each separation groove 22 is set. The connecting portion 150
connecting the pair of side electrodes 142 remains. The connecting portion 150 is joined to the
upper end of the corresponding ground lead 138.
[0092]
As described above, also in this embodiment, it is possible to collectively form the plurality of
ground connection structures 135 by repeating the groove formation and the groove filling.
Further, side electrodes are formed on both sides of each vibrating element in the X direction,
that is, ground connection structures 135 can be formed on both sides of each vibrating element
in the X direction. There is an advantage that vibration characteristics can be realized.
[0093]
Next, some configuration examples of the backing will be described with reference to FIGS. First,
a first example of the backing will be described with reference to FIGS.
[0094]
As shown in FIG. 26, a backing plate 190, a lead frame 186 and a backing plate 182 are used to
form a bonded body. The backing plate 190 is formed of a flat backing material, and the backing
plate 182 has the same form as the above backing plate 190, but a plurality of grooves 184 are
formed on the top surface thereof. The lead frame 186 has a plurality of leads 188, each lead
188 being embedded in each groove 184.
[0095]
By bonding the backing plate 190 and the backing plate 182 while inserting the leads 188 into
the grooves 184, a bonded body 192 shown in FIG. 27 can be formed. By alternately bonding the
plurality of bonding members 192 and the plurality of conductive plates 194, the backing 196
can be configured as shown in FIG. Here, each lead 188 shown in FIG. 26 constitutes a signal
04-05-2019
31
lead, and each conductive plate 194 as a spacer shown in FIG. 27 constitutes a ground lead.
[0096]
Next, a second example of the backing will be described with reference to FIGS.
[0097]
FIG. 29 shows one corresponding to the bonded body 192 shown in FIG.
A plurality of grooves 198 are formed in the bonding body 192 from the upper surface side.
Although the bonded body 192 is composed of the upper backing plate 192B and the lower
backing plate 192A, the lower backing plate 192A is slightly thicker than the upper backing
plate 192B. In forming the plurality of grooves 198, the grooves 198 are formed to such a depth
that the lower backing plate 192A is not completely cut.
[0098]
Next, as shown in FIG. 30, a conductive material is filled in the respective grooves 198 shown in
FIG. 29, and a conductive layer 200A is formed on the upper surface side of the bonded body
with a certain thickness. Moreover, the lower surface side in the bonding body 190 is chamfered
and removed with a fixed thickness. Then, a backing 202 as shown in FIG. 31 can be constructed
by arranging and stacking a plurality of elements shown in FIG. As shown, a conductive material
is provided around each lead, ie, each lead is encased by the conductive material. According to
such a backing, it is possible to enhance the shielding performance for each vibrating element.
[0099]
32 to 36 show a third example of the backing.
[0100]
As shown in FIG. 32, electrode layers 214 and 216 are formed on the upper and lower surfaces
of the backing plate 212.
04-05-2019
32
As shown in FIG. 33, the electrode layer on the top surface side is etched to form a plurality of
leads 218 on the top surface.
[0101]
Then, as shown in FIG. 34, the backing plate 220 is bonded to the upper surface of the backing
plate 210 after the plurality of leads are formed. A plurality of grooves 222 are formed on the
lower surface side of the backing plate 220, and each lead enters into each groove 222. Then, a
bonded body 224 as shown in FIG. 35 is formed. The lower surface side of the bonded body 224
has an electrode layer 216 with a certain thickness. Then, a plurality of the elements 208 shown
in FIG. 35 can be arranged side by side to form a backing 210 as shown in FIG.
[0102]
As described above, various methods can be employed as a method of manufacturing the
backing, and in any case, it is desirable that the signal lead array and the ground lead array can
be configured according to the vibration element pattern. In the above embodiment, a plurality of
vibration elements may partially include a vibration element that does not function by
transmission and reception. For example, the 2D array transducer described above may be a
sparse 2D array transducer. The present invention can also be applied to, for example, a 1.5D
array transducer by expanding the above-described method. According to the ultrasonic probe
shown in each of the above embodiments, the acoustic characteristics and the electric
characteristics of the respective transducer elements constituting the 2D array transducer can be
made excellent. There is an advantage that the sensitivity can be increased, and as a result, an
ultrasound image with good image quality can be constructed.
[0103]
FIG. 1 is a perspective view of a first embodiment of a transducer assembly. FIG. 2 is an enlarged
cross-sectional view of the transducer assembly shown in FIG. It is a figure for demonstrating the
process of a piezoelectric plate and a backing. It is a figure which shows the bonded state of a
piezoelectric plate and a backing. It is a figure which shows the state which formed the several
base groove. It is a figure which shows the state which filled the electroconductive member with
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respect to several base groove. It is a figure which shows the state which joined the alignment
plate with respect to the laminated body. It is a figure which shows the state in which several
ground electrode structure is formed by formation of several isolation groove. FIG. 7 is a
perspective view of a second embodiment of a transducer assembly. It is a figure for
demonstrating the process of a lamination type piezoelectric plate and a backing. It is a figure for
demonstrating the vapor deposition process with respect to a laminated piezoelectric plate. It is a
figure which shows the bonding state of a laminated piezoelectric plate and a backing. It is a
figure for demonstrating formation of several 1st foundation grooves. It is a figure for
demonstrating the filling of the electroconductive member with respect to several 1st base
groove. It is a figure which shows the state which joined the alignment plate with respect to the
laminated body. It is a figure which shows the state in which several ground connection
structures and several signal connection structures are formed by formation of several isolation
groove. FIG. 7 is a perspective view of a third embodiment of a transducer assembly. It is a figure
for demonstrating the process of a piezoelectric plate and a backing. It is a figure which shows
the bonded state of a piezoelectric plate and a backing. It is a figure for demonstrating formation
of several 1st foundation grooves. It is a figure for demonstrating the filling of the insulating
member with respect to several 1st base groove. It is a figure for demonstrating formation of
several 2nd foundation grooves. It is a figure for demonstrating the filling of the
electroconductive member with respect to several 2nd base groove. It is a figure for
demonstrating joining of the alignment plate with respect to a laminated body. It is a figure for
demonstrating formation of the several ground connection structure by formation of several
isolation groove. It is a figure for demonstrating the manufacturing method of the components in
the 1st example of a backing. It is a figure for demonstrating lamination of a plurality of parts in
the 1st example of backing. It is a perspective view which shows the 1st example of a backing. It
is a figure for demonstrating the components in the 2nd example of a backing. It is a figure for
demonstrating formation of the electroconductive material with respect to components. It is a
perspective view which shows the 2nd example of a backing. It is a figure for demonstrating the
plate used for the 3rd example of a backing. It is a figure which shows the state after the etching
with respect to the plate shown in FIG. It is a figure for demonstrating the components in the 3rd
example of a backing.
It is a figure which shows the bonding state of the components in the 3rd example of a backing.
It is a perspective view which shows the 3rd example of a backing.
Explanation of sign
[0104]
DESCRIPTION OF REFERENCE NUMERALS 10 vibrator assembly, 14 2D array vibrator, 15
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vibrator element, 16 backing, 18 matching layer, 20, 22 separation groove, 24 signal lead, 26
ground lead, 30 upper surface electrode, 32 lower surface electrode, 34 side electrode, 40
ground Connection structure.
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