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DESCRIPTION JPWO2017042997

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DESCRIPTION JPWO2017042997
Abstract: The present invention provides an ultrasonic array transducer having a high impedance
matching effect and excellent productivity, a method of manufacturing an ultrasonic array
transducer, an ultrasonic probe, and an ultrasonic diagnostic apparatus. An ultrasonic array
transducer according to the present technology includes an ultrasonic transducer (130) and a
semiconductor chip (140). The ultrasound transducers (130) constitute an array. The
semiconductor chip (140) is bonded to each of the ultrasonic transducers (130) to form an
impedance matching circuit.
Ultrasonic array transducer, method of manufacturing ultrasonic array transducer, ultrasonic
probe and ultrasonic diagnostic apparatus
[0001]
The present technology relates to an ultrasonic array transducer that can be used for ultrasonic
imaging, a method of manufacturing an ultrasonic array transducer, an ultrasonic probe, and an
ultrasonic diagnostic apparatus.
[0002]
An ultrasonic diagnostic apparatus, which is increasingly used in the medical field, generates an
ultrasonic image of an object to be diagnosed by irradiating an ultrasonic wave to an object to be
diagnosed from an ultrasonic probe and detecting a reflected wave by the ultrasonic probe. Do.
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The ultrasound probe includes an array transducer in which a plurality of ultrasound transducers
are arrayed, and adjusts delay times of drive signals input to the ultrasound transducers and
detection signals output from the ultrasound transducers. Thus, it is possible to control the
focusing point of ultrasonic waves.
[0003]
Array transducers include 1D arrays in which ultrasonic transducers are linearly arrayed and 2D
arrays in which transducers are arrayed in a planar array, but they are mounted on one array
transducer to improve resolution and imaging speed. The number of ultrasonic transducers tends
to increase. In addition, the spread of ultrasonic catheters and the like inserted into blood vessels
and the like has progressed, and miniaturization of ultrasonic probes has been required. For this
reason, high-density mounting of ultrasonic transducers is required, and the mounting area of
individual ultrasonic transducers tends to be small.
[0004]
On the other hand, if the mounting area of the ultrasonic transducer is reduced, the impedance
may be mismatched and the detection sensitivity of the ultrasonic wave may be degraded. As a
measure against this, impedance matching is performed using an amplifier, and generally an
ASIC (application specific integrated circuit) is used (see, for example, Patent Document 1).
[0005]
Unexamined-Japanese-Patent No. 2006-166985
[0006]
However, ASICs need to have a certain size, and it is difficult to secure an installation place when
installed on individual transducers.
Although it is possible to separate the ASIC from the vibrator and install it, the longer the wire
connecting the ASIC and the vibrator, the smaller the effect of impedance matching. Furthermore,
the ASIC needs to be designed according to the structure of the array transducer, which makes it
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difficult to reduce the manufacturing cost.
[0007]
In view of the above circumstances, the object of the present technology is to provide an
ultrasonic array transducer having a high impedance matching effect and excellent productivity,
a method of manufacturing an ultrasonic array transducer, an ultrasonic probe and an ultrasonic
diagnostic apparatus. It is to do.
[0008]
In order to achieve the above object, an ultrasonic array transducer according to an embodiment
of the present technology includes an ultrasonic transducer and a semiconductor chip.
The ultrasonic transducers constitute an array. The semiconductor chip is bonded to each of the
ultrasonic transducers to form an impedance matching circuit.
[0009]
According to this configuration, since the ultrasonic transducer and the impedance matching
circuit are integrated, and the wiring connecting the two may be short, a high impedance
matching effect is obtained, and the SNR (signal-noise ratio) is improved. As a result, the contrast
improvement of the ultrasound image can be realized. In addition, when mounting a module
(hereinafter referred to as a transducer module) in which an ultrasonic transducer and an
impedance matching circuit are integrated on a substrate, there is a high degree of freedom in
arrangement and array formation or placement of ultrasonic transducers having different
frequencies. Optimization is easy. Furthermore, by arranging transducer modules of a specific
structure in an arbitrary shape, it is possible to correspond to various devices, and it is possible
to reuse the transducer modules between devices. In addition, if the footprint of the
semiconductor chip is exceeded, the same semiconductor chip can be used for ultrasonic
transducers of any size.
[0010]
The impedance matching circuit may include an amplifier and a TR (transmit-receive) switch.
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[0011]
Although a drive signal for generating an ultrasonic wave and a detection signal generated by
detection of the ultrasonic wave flow in the ultrasonic transducer, the signal intensity is largely
different between the drive signal and the detection signal.
According to the above configuration, only the detection signal can be amplified by the amplifier
by switching the signal path by the TR switch, and the impedance matching circuit can be
formed.
[0012]
The semiconductor chip may include a first semiconductor chip provided with the amplifier and a
second semiconductor chip provided with the TR switch.
[0013]
By forming the impedance matching circuit with a plurality of semiconductor chips, the size of
each semiconductor chip can be reduced, and the impedance matching circuit can be mounted
even on a small ultrasonic transducer.
[0014]
The semiconductor chip may be an SOI (Silicon on Insulator) chip.
[0015]
The SOI chip has advantages such as small size and small leakage current, and is suitable as a
semiconductor chip to be bonded to an ultrasonic transducer.
[0016]
The ultrasonic transducer has a first ultrasonic transducer having a first frequency as a center
frequency of vibration, and a second ultrasonic transducer having a second frequency different
from the first frequency as a center frequency of vibration. And an acoustic transducer may be
included.
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[0017]
Although the vibration frequency of the ultrasonic transducer differs depending on the thickness
of the piezoelectric layer, by integrating the ultrasonic transducer and the impedance matching
circuit, the ultrasonic transducers with largely different vibration frequencies are also arranged
with high degree of freedom It is possible to
[0018]
The ultrasonic array transducer may further include a micro electro mechanical system (MEMS)
that constitutes an array together with the ultrasonic transducer.
[0019]
By arraying the ultrasonic transducers and the MEMS, the generation of ultrasonic waves can be
performed by the ultrasonic transducers with high ultrasonic intensity, the detection of the
reflected waves can be performed by the high sensitivity MEMS, and the detection sensitivity is
improved It becomes possible to realize.
[0020]
The ultrasonic array transducer may further include an optical element forming an array
together with the ultrasonic transducer.
[0021]
By arraying the ultrasonic transducer and the optical element, it is possible to realize optical
ultrasonic imaging in which ultrasonic waves generated by light irradiated from the optical
element are detected by the ultrasonic transducer with one array.
[0022]
In order to achieve the above object, in a method of manufacturing an ultrasonic array
transducer according to an embodiment of the present technology, an ultrasonic transducer to
which a semiconductor chip forming an impedance matching circuit is bonded is mounted by a
pick and place method.
[0023]
The ultrasonic transducer has a first ultrasonic transducer having a first frequency as a center
frequency of vibration, and a second ultrasonic transducer having a second frequency different
from the first frequency as a center frequency of vibration. And an acoustic transducer may be
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included.
[0024]
In the method of manufacturing the ultrasonic array transducer, the MEMS may be mounted
together with the ultrasonic transducer by a pick and place method.
[0025]
In the method of manufacturing an ultrasonic array transducer, an optical element may be
mounted together with the ultrasonic transducer by a pick and place method.
[0026]
In order to achieve the above object, an ultrasound probe according to one form of the present
technology includes ultrasound array vibration.
The ultrasonic array transducer includes an ultrasonic transducer forming an array, and a
semiconductor chip forming an impedance matching circuit bonded to each of the ultrasonic
transducers.
[0027]
In order to achieve the above object, an ultrasonic diagnostic apparatus according to an
embodiment of the present technology includes an ultrasonic probe and a main body.
The ultrasonic probe comprises an ultrasonic array transducer having an ultrasonic transducer
forming an array, and a semiconductor chip forming an impedance matching circuit bonded to
each of the ultrasonic transducers.
The main body is connected to the ultrasonic probe, supplies a drive signal to the ultrasonic
array transducer, and generates an ultrasonic image based on a detection signal output from the
ultrasonic array transducer.
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[0028]
As described above, according to the present technology, it is possible to provide an ultrasonic
array transducer having a high impedance matching effect and excellent productivity, a method
of manufacturing an ultrasonic array transducer, an ultrasonic probe, and an ultrasonic
diagnostic apparatus. It is possible.
In addition, the effect described here is not necessarily limited, and may be any effect described
in the present disclosure.
[0029]
FIG. 3 is a schematic view of an ultrasonic diagnostic apparatus according to an embodiment of
the present technology. FIG. 6 is a cross-sectional view of an ultrasonic array transducer provided
in the ultrasonic diagnostic apparatus.
It is a perspective view of a transducer module with which the ultrasonic array transducer is
provided.
It is a schematic diagram which shows the circuit structure of the vibrator | oscillator module
with which the ultrasonic array vibrator | oscillator is provided.
It is a schematic diagram which shows the manufacturing method of the ultrasonic array vibrator
| oscillator.
It is a schematic diagram which shows the manufacturing method of the ultrasonic array vibrator
| oscillator.
It is a schematic diagram which shows the manufacturing method of the ultrasonic array vibrator
| oscillator.
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It is a schematic diagram which shows the manufacturing method of the ultrasonic array vibrator
| oscillator.
It is a schematic diagram which shows the manufacturing method of the ultrasonic array vibrator
| oscillator.
It is a schematic diagram which shows the arrangement | sequence of the vibrator | oscillator
module with which the ultrasonic array vibrator | oscillator is equipped.
It is a schematic diagram which shows the arrangement | sequence in the convex type | mold
ultrasonic probe of the transducer | module which the same ultrasound array transducer |
vibrator comprises.
It is a schematic diagram which shows the arrangement | sequence in the Hanafee-lens type |
mold ultrasonic probe of the vibrator | oscillator module with which the same ultrasonic array
vibrator | oscillator is provided. It is a perspective view which shows the 1D array array of the
vibrator | oscillator module with which the ultrasonic array vibrator | oscillator is equipped. It is
a schematic diagram which shows the circuit structure of the vibrator | oscillator module with
which the ultrasonic array vibrator | oscillator is provided. It is a schematic diagram of IVUS
provided with the ultrasonic array transducer which concerns on a comparative example. It is a
schematic diagram of IVUS provided with the ultrasonic array transducer which concerns on
embodiment of this technique. FIG. 6A is a cross-sectional view of an ultrasound array transducer
comprising a transducer module and a MEMS module according to an embodiment of the present
technology. It is a schematic diagram which shows the arrangement | sequence of the ultrasonic
array vibrator | oscillator same. It is a schematic diagram which shows the manufacturing
method of the ultrasonic array vibrator | oscillator. 1 is a cross-sectional view of an ultrasound
array transducer including a transducer module and an optical element module according to an
embodiment of the present technology. It is a schematic diagram which shows the arrangement |
sequence of the ultrasonic array vibrator | oscillator same. It is a schematic diagram which shows
the manufacturing method of the ultrasonic array vibrator | oscillator.
[0030]
[Configuration of Ultrasonic Diagnostic Apparatus] FIG. 1 is a schematic view showing a
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configuration of an ultrasonic diagnostic apparatus 1 according to the present embodiment. As
shown in the figure, the ultrasonic diagnostic apparatus 1 includes a main body 11, an ultrasonic
probe 12 and a cable 15. The main body 11 and the ultrasonic probe 12 are connected by a
cable 15.
[0031]
The main body 11 supplies a drive signal to the ultrasonic probe 12 via the cable 15, and
generates an ultrasonic image from the detection signal of the ultrasonic wave output from the
ultrasonic probe 12 and causes the display to display the ultrasonic image.
[0032]
The ultrasonic probe 12 includes an array transducer 121, contacts an object to be diagnosed,
emits an ultrasonic wave, and detects a reflected wave.
The ultrasonic probe 12 receives supply of a drive signal from the main body 11 via the cable 15
and outputs a detection signal to the main body 11.
[0033]
The type of ultrasonic probe 12 is not particularly limited, and may be any of various linear,
sector, convex, etc. or radial type ultrasonic probes, and may be a two-dimensional array. The
ultrasound probe 12 may be an ultrasound catheter that can be inserted into a blood vessel or
the like.
[0034]
[Configuration of Array Vibrator] FIG. 2 is a cross-sectional view showing a structure of the array
vibrator 121. As shown in FIG. As shown in the figure, the array transducer 121 includes a
substrate 122, a transducer layer 123, an upper electrode layer 124, an acoustic matching layer
125, and an acoustic lens 126. These are laminated in the order of the substrate 122, the
transducer layer 123, the upper electrode layer 124, the acoustic matching layer 125 and the
acoustic lens 126.
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[0035]
The substrate 122 is a substrate such as a rigid printed circuit board or an FPC (flexible printed
circuits) board, and the wiring H and the bumps B are formed on the mounting surface. The
wiring H is connected to the main body 11 via the cable 15.
[0036]
The transducer layer 123 is composed of a plurality of transducer modules 120 and a filler 127.
The plurality of transducer modules 120 are each mounted on the substrate 122 by the bumps B,
and the filler material 127 is filled between the transducer modules 120. The filler 127 can be an
acrylic resin, a polyurethane resin, or an acoustic absorber. Details of the transducer module 120
will be described later.
[0037]
Although only three transducer modules 120 are shown in FIG. 2, actually, the array transducer
121 is provided with a larger number (about several hundreds to several thousands) of
transducer modules 120.
[0038]
The upper electrode layer 124 functions as an electrode of a piezoelectric layer 131 described
later.
The upper electrode layer 124 is made of a conductive material, for example, metal plating. Note
that the upper electrode layer 124 may be formed across a plurality of transducer modules 120
as shown in FIG. 2, or may be separated for each transducer module 120.
[0039]
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The acoustic matching layer 125 reduces the difference in acoustic impedance between the
object to be diagnosed and the ultrasonic transducer 130 and prevents the reflection of
ultrasound on the object to be diagnosed. The acoustic matching layer 125 is made of synthetic
resin or ceramic material. The acoustic matching layer 125 may have two layers as shown in FIG.
2, or one or more layers.
[0040]
The acoustic lens 126 focuses the ultrasonic waves generated in the transducer layer 123. The
acoustic lens 126 is located at the tip of the ultrasonic probe 12 as shown in FIG. 1 and contacts
an object to be diagnosed. The acoustic lens 126 is made of silicone rubber or the like, and its
size and shape are not particularly limited.
[0041]
[Configuration of Transducer Module] FIG. 3 is a schematic view of the transducer module 120.
As shown in FIG. As shown in the figure, the transducer module 120 includes an ultrasonic
transducer 130 and a circuit chip 140. The power supply wiring 151, the signal wiring 152, and
the ground wiring 153 are connected to each transducer module 120.
[0042]
The ultrasonic transducers 130 each include a piezoelectric layer 131, a lower electrode layer
132, and a backing layer 133. These are laminated in the order of the backing layer 133, the
lower electrode layer 132 and the piezoelectric layer 131.
[0043]
The piezoelectric layer 131 is made of a piezoelectric material such as PZT (lead zirconate
titanate). When a voltage is applied between the lower electrode layer 132 and the upper
electrode layer 124 (see FIG. 2), the piezoelectric layer 131 generates a vibration due to the
inverse piezoelectric effect to generate an ultrasonic wave. In addition, when a reflected wave
from an object to be diagnosed enters the piezoelectric layer 131, polarization occurs due to the
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piezoelectric effect. The size of the piezoelectric layer 131 is not particularly limited, but can be,
for example, 250 μm square.
[0044]
The lower electrode layer 132 functions as an electrode of the piezoelectric layer 131. The lower
electrode layer 132 is made of a conductive material, for example, metal plating.
[0045]
The backing layer 133 is stacked on the circuit chip 140 and absorbs unnecessary vibration of
the ultrasonic transducer 130. The backing layer 133 is made of a material in which a filler and a
synthetic resin are mixed.
[0046]
The circuit chip 140 is bonded to each of the ultrasonic transducers 130 to constitute an
impedance matching circuit of the ultrasonic transducers 130. The circuit chip 140 is a
semiconductor chip made of a semiconductor material. Specifically, the circuit chip 140 can be
an SOI chip formed by an SOI (Silicon on Insulator) process. More specifically, the circuit chip
140 can be a BGD-SOI chip fabricated by a BCD-SOI (bipolar-CMOS-DMOS) process.
[0047]
The circuit chips 140 only need to be bonded to the ultrasonic transducer 130, and may not
necessarily be disposed between the backing layer 133 and the substrate 122. In addition, the
circuit chip 140 may not be bonded to all the ultrasonic transducers 130, and may be bonded to
only some of the ultrasonic transducers 130. The size of the circuit chip 140 can be equal to or
smaller than the bottom surface of the ultrasonic transducer 130.
[0048]
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FIG. 4 is a schematic view showing a circuit configuration of the circuit chip 140. As shown in
FIG. As shown in the figure, the circuit chip 140 includes a first TR (transmit-receive) switch 141,
an amplifier 142 and a second TR switch 143.
[0049]
The power supply wiring 151 is connected to the amplifier 142. The signal wiring 152 is
connected to the upper electrode layer 124, and is divided into a signal wiring 152A not passing
through the amplifier 142 and a signal wiring 152B passing through the amplifier 142. The
ground wiring 153 is connected to the lower electrode layer 132.
[0050]
The first TR switch 141 is connected to the signal wiring 152, and switches the signal path
between the signal wiring 152A and the signal wiring 152B. The first TR switch 141 can be a
transistor or a diode.
[0051]
The amplifier 142 is connected to the signal wiring 152 B, and uses the power supplied from the
power supply wiring 151 to amplify a signal flowing through the signal wiring 152 B. アンプ
142は、ダイオードとすることができる。
[0052]
The second TR switch 143 is connected to the signal wiring 152, and switches the signal path
between the signal wiring 152A and the signal wiring 152B. Switch the signal path. The second
TR switch 143 can be a transistor or a diode.
[0053]
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The transducer module 120 has the above configuration. As described above, since the
transducer module 120 is provided with the circuit chip 140 which configures the impedance
matching circuit, the wiring length between the ultrasonic transducer and the impedance
matching circuit is short, and the effect of the impedance matching is high. As a result, it is
possible to realize an improvement in signal-noise ratio (SNR) and, in turn, an improvement in the
contrast of ultrasound images.
[0054]
[Operation of Ultrasonic Diagnostic Apparatus] The operation of the ultrasonic diagnostic
apparatus 1 will be described. When the ultrasonic diagnostic apparatus 1 is powered on, power
is supplied from the main body 11 to the ultrasonic probe 12 via the cable 15 (see FIG. 1). The
power flows to the power supply wiring 151 through the substrate 122 and is supplied to the
amplifier 142 (see FIG. 4).
[0055]
When the ultrasonic probe 12 abuts on the object to be diagnosed and a diagnostic start
instruction is input, the main body 11 generates a drive signal. The drive signal is supplied to the
ultrasonic probe 12 through the cable 15 and flows to the signal wiring 152 through the
substrate 122. At this time, the first TR switch 141 and the second TR switch 143 are switched to
the signal wiring 152 A side, and the drive signal is supplied to the upper electrode layer 124 via
the second TR switch 143 and the first TR switch 141.
[0056]
Due to the potential difference between the upper electrode layer 124 and the lower electrode
layer 132, vibration due to the reverse piezoelectric effect is generated in the piezoelectric layer
131, and an ultrasonic wave is generated. The generated ultrasonic waves are incident on the
object to be diagnosed through the acoustic matching layer 125 and the acoustic lens 126.
[0057]
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The reflected wave generated in the object to be diagnosed enters the piezoelectric layer 131 via
the acoustic lens 126 and the acoustic matching layer 125. Polarization occurs in the
piezoelectric layer 131 due to the piezoelectric effect, and a current (hereinafter, a detection
signal) flows in the signal wiring 152. At this time, the first TR switch 141 and the second TR
switch 143 are switched to the signal wiring 152 B side, and the detection signal is amplified by
the amplifier 142. The amplified detection signal flows from the first TR switch 141 to the signal
wiring 152, and is transmitted to the main body 11 via the substrate 122 and the cable 15.
[0058]
The main body 11 generates an ultrasonic image based on the detection signal. As described
above, the drive signal is transmitted to the upper electrode layer 124 without passing through
the amplifier 142, but the detection signal is amplified by the amplifier 142 and transmitted to
the main body 11. The switching of the paths of the drive signal and the detection signal is
performed by the first TR switch 141 and the second TR switch 143. Thereby, matching of the
impedance of the drive signal with large signal strength and the detection signal with small
signal strength is realized.
[0059]
[Method of Manufacturing Array Vibrator] FIGS. 5 to 8 are schematic views showing a method of
manufacturing the array vibrator 121. FIG. As shown in FIG. 5A, the circuit chip 140 is disposed
on the sacrificial substrate K. The circuit chip 140 can be bonded to the sacrificial substrate K by
an adhesive that peels off by UV (ultraviolet) radiation.
[0060]
Subsequently, as shown in FIG. 5B, a backing layer 133 is stacked on the sacrificial substrate K
and the circuit chip 140. Subsequently, as shown in FIG. 5C, a part of the backing layer 133 is
removed to expose the circuit chip 140. An opening formed by removal is referred to as an
opening 133a.
[0061]
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15
Subsequently, as shown in FIG. 6A, the conductor D1 is disposed in the opening 133a and on the
backing layer 133. The conductor D1 is made of, for example, a metal such as copper.
Subsequently, as shown in FIG. 6B, the conductor D2 is disposed on the conductor D1. The
conductor D2 can be a conductive adhesive. The conductor D1 and the conductor D2 constitute
the lower electrode layer 132.
[0062]
Subsequently, as shown in FIG. 6C, the piezoelectric layer 131 is disposed on the conductor D2
and adhered by the conductor D2. Subsequently, as shown in FIG. 7A, the piezoelectric layer 131
and the backing layer 133 are cut by dicing and separated into individual transducer modules
120.
[0063]
Subsequently, the transducer module 120 is separated from the sacrificial substrate K. The
adhesion between the circuit chip 140 and the sacrificial substrate K can be peeled off by
ultraviolet irradiation. FIG. 7B is a schematic view showing the transducer module 120 separated
from the sacrificial substrate K.
[0064]
Subsequently, as shown in FIG. 7C, the transducer module 120 is mounted on the substrate 122.
As shown in the figure, the wiring H and the bump B are formed on the substrate 122. The
wiring H is the power supply wiring 151, the signal wiring 152, and the ground wiring 153. The
vibrator module 120 can be mounted on the substrate 122 by connecting the circuit chip 140 to
the wiring H by the bumps B.
[0065]
Subsequently, as shown in FIG. 8A, the other transducer modules 120 are mounted on the
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substrate 122, respectively. Note that a method for individually mounting mounting objects in
this manner is called a pick & place method.
[0066]
Subsequently, as shown in FIG. 8B, the filler material 127 is filled between the transducer
modules 120 to form the transducer layer 123. Subsequently, as shown in FIG. 8C, the upper
electrode layer 124 and the acoustic matching layer 125 are stacked on the transducer layer
123.
[0067]
Subsequently, the acoustic lens 126 is laminated on the acoustic matching layer 125 (see FIG. 2).
The array vibrator 121 can be manufactured as described above. As described above, the array
transducer 121 according to the present embodiment can be mounted by the pick and place
method because the ultrasonic transducer 130 and the circuit chip 140 are integrally configured.
[0068]
Here, the array transducers used in the ultrasound diagnostic apparatus have about several
thousand ultrasound transducers, and in the case of medical ultrasound probes, in particular, the
configuration of the ultrasound probe differs depending on each diagnostic subject. The pick and
place method does not cost much.
[0069]
In addition, conventionally, it has been necessary to individually manufacture array transducers
for various types of ultrasonic probes having different shapes of array transducers.
On the other hand, in the present embodiment, since the transducer module 120 can be freely
disposed by the pick and place method, the transducer module 120 having the same structure
can be used for various ultrasonic probes.
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[0070]
The method of manufacturing the array vibrator 121 is not limited to the above. FIG. 9 is a
schematic view showing another method of manufacturing the array vibrator 121. As shown in
FIG. After disposing the circuit chip 140 on the sacrificial substrate K as shown in FIG. 5A, the
backing layer 133 is formed with a thickness equal to the thickness of the circuit chip 140 as
shown in FIG. 9A.
[0071]
Further, as shown in FIG. 9B, a structure in which the backing layer 133, the conductor D1 and
the conductor D2 are stacked is manufactured. It is possible to produce the structure shown in
FIG. 6 (b) by laminating the laminate on the structure shown in FIG. 9 (a). Thereafter, the array
vibrator 121 can be manufactured by the same manufacturing method as that described above.
[0072]
[Regarding Arrangement of Transducer Modules] As described above, in the ultrasound probe 12
according to the present embodiment, the ultrasound transducers 130 each include the
transducer module 120 in which the circuit chip 140 is provided, and for each transducer
module It can be mounted on the substrate 122. Therefore, the degree of freedom in the
arrangement of the transducer modules 120 is high.
[0073]
FIG. 10 is a schematic view showing the arrangement of the transducer modules 120, and is a
view of the transducer modules 120 from the direction perpendicular to the substrate 122 (see
FIG. 2). As shown to the same figure, the vibrator | oscillator module 120 can be made into a
honeycomb 2D arrangement. The honeycomb 2D arrangement is an arrangement in which a line
connecting center points of the transducer modules 120 viewed from a direction perpendicular
to the substrate 122 is a regular hexagon.
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[0074]
In general, the problem with ultrasonic probes is the reduction of side lobes (ultrasonic waves
emitted in the direction away from the central direction to which ultrasonic waves are directed).
In the honeycomb 2D arrangement, since the distance between the adjacent ultrasonic
transducers 130 can be increased, side lobes can be suppressed.
[0075]
In particular, the dice-and-fill (Dice & Fill) method conventionally used in the manufacture of
array vibrators arranges electrodes of a large honeycomb 2D array on small and diced
piezoelectric elements in a lattice, but this method is a substantial element The pitch is reduced.
On the other hand, in the array transducer 121 according to the present embodiment, it is
possible to arrange the ultrasonic transducers 130 at the minimum pitch of element processing
by the pick and place method.
[0076]
FIG. 11 is a schematic view of a convex ultrasonic probe configured by the transducer module
120 according to the present embodiment. As shown in the figure, in the convex ultrasonic
probe, the transducer modules 120 need to be arranged in a curved surface. However, in the
conventional structure in which the impedance matching circuit is realized by the ASIC, it is
difficult to arrange the ASIC on the curved surface.
[0077]
On the other hand, since the array transducer 121 according to the present embodiment is
constituted by the transducer module 120 in which the circuit chip 140 is integrated with the
ultrasonic transducer 130, as shown in FIG. 120 can be mounted at high density. Thereby, it is
possible to improve the contrast of the ultrasound image and to improve the slice resolution
(resolution in the depth direction of the object to be diagnosed).
[0078]
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FIG. 12 is a schematic view showing a Hanafee lens type ultrasonic probe configured by the
transducer module 120 according to the present embodiment. The Hanafee lens is an array of
two or more ultrasonic transducers different in the frequency of the generated ultrasonic wave in
order to improve the slice resolution.
[0079]
As shown in the figure, the array transducer 121 has a transducer module 120L including an
ultrasonic transducer 130L having a low central frequency of vibration (a large aperture
diameter) and a high central frequency of vibration (a small aperture diameter) It comprises the
transducer module 120H provided with the ultrasonic transducer 130H. Since the frequency of
the ultrasonic transducer 130 is determined by the thickness of the piezoelectric layer 131, the
piezoelectric layer 131 included in the ultrasonic transducer 130L and the piezoelectric layer
131 included in the ultrasonic transducer 130 have different thicknesses.
[0080]
The Hanafee lens can make the ultrasonic beam diameter uniform in the depth direction by
changing the focal position of the ultrasonic wave on the inner and outer peripheral sides. As
described above, since the frequency of the ultrasonic transducer is determined by the thickness
of the piezoelectric layer, conventionally, the array transducer is manufactured by dicing for
processing the piezoelectric layer into a curved surface and dicing for separating the
piezoelectric layer. It was On the other hand, in the present embodiment, the ultrasonic
transducers 130 having different thicknesses of the piezoelectric layer 131 can be manufactured
in advance and can be individually mounted by the pick and place method.
[0081]
As a result, it is possible to manufacture the array transducer 121 in which the difference in
frequency between the ultrasonic transducer 130L and the ultrasonic transducer 130H is large
as compared to the case where carving is used. In addition, the arrangement of the ultrasonic
transducer 130L and the ultrasonic transducer 130H can be freely determined. Furthermore,
even in the case of the Hanafee lens, the above-mentioned honeycomb 2D arrangement can be
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made, and the side lobe can be reduced.
[0082]
[Regarding Arrangement and Number of Circuit Chips] As described above, the transducer
module 120 configuring the array transducer 121 is configured of the ultrasonic transducer 130
and the circuit chip 140. Here, the circuit chip 140 may be not a single chip but a plurality of
chips.
[0083]
FIG. 13 is a schematic view showing an array vibrator 121 configured of a vibrator module 120
including a plurality of circuit chips. As shown in the figure, the array transducer 121 can also be
a narrow pitch 1D array in which ultrasonic transducers 130 having a narrow width are arrayed
in one direction. The circuit chip 140 can include three circuit chips: a circuit chip 140A, a circuit
chip 140B, and a circuit chip 140C.
[0084]
FIG. 14 is a schematic view showing a circuit configuration of the circuit chips 140A to 140C. As
shown in the figure, the circuit chip 140A may include the second TR switch 143, the circuit chip
140B may include the amplifier 142, and the circuit chip 140C may include the first TR switch
141. The operations of the first TR switch 141, the amplifier 142 and the second TR switch 143
are the same as those described above. The circuit chips 140A to 140C may be produced by
dicing the circuit chip 140 or may be produced individually.
[0085]
By dividing the circuit chip 140 into elements constituting the impedance matching circuit, the
size of the circuit chip 140 can be reduced, and ultrasonic waves can be generated even if the
width of the ultrasonic transducer 130 is narrow as in a narrow pitch 1D array. Bonding to the
vibrator 130 is possible. The circuit chip 140 may include two circuit chips. For example, the
circuit chip 140 may include a circuit chip including the amplifier 142 and a circuit chip
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including the first TR switch 141 and the second TR switch 143.
[0086]
[Application to IVUS] IVUS (intravascular ultrasound) is a type of ultrasound probe and is used to
observe the vascular wall of coronary coronary vessels. The IVUS includes an array transducer in
which a plurality of ultrasonic transducers are circumferentially arranged, and an amplifier for
amplifying a detection signal output from each ultrasonic transducer.
[0087]
FIG. 15 is a schematic view of an IVUS 300 having a conventional structure. As shown in the
figure, the IVUS 300 includes a catheter 301, an array transducer 302, a signal processing chip
303, and a wire 304. The ultrasonic wave generated in the array transducer 302 is irradiated to
the blood vessel wall through the catheter 301 inserted into the blood vessel, and the reflected
wave is incident on the array transducer 302 through the catheter 301 and detected. The
detection signal is amplified in the signal processing chip 303 and transmitted to the main body
via the wiring 304.
[0088]
As described above, in the IVUS 300, the signal processing chip 303 needs to be provided
separately from the array transducer 302, and the refraction of the IVUS 300 is prevented by the
signal processing chip 303, making it difficult to operate the catheter 301.
[0089]
FIG. 16 is a schematic view of an IVUS 400 using the array transducer 121 according to the
present embodiment.
As shown in the figure, the IVUS 400 includes a catheter 401, an array transducer 121, and a
wire 402. The ultrasonic wave generated in the array transducer 121 is irradiated to the blood
vessel wall through the catheter 401 inserted into the blood vessel, and the reflected wave is
incident on the array transducer 121 through the catheter 401 and detected. The detection
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signal is amplified in the circuit chip 140 included in the array vibrator 121 and transmitted to
the main body through the wiring 402.
[0090]
Since the array vibrator 121 includes the circuit chip 140, the IVUS 400 does not need to have a
signal processing chip separately from the array vibrator 121. Thus, the refraction of the IVUS
400 is not impeded by the signal processing tip, which facilitates the operation of the catheter
401. Although the IVUS 400 may be provided with a signal processing chip different from the
impedance matching circuit in some cases, the impedance matching circuit is unnecessary even
in such a case, so that the size of the signal processing chip can be reduced.
[0091]
[Mixed Loading of Ultrasonic Transducer and MEMS] The transducer module 120 according to
the present embodiment can be loaded together with a MEMS module provided with MEMS
(Micro Electro Mechanical Systems).
[0092]
FIG. 17 is a schematic view showing an array vibrator 160 in which a vibrator module and a
MEMS module are mixedly mounted.
As shown in the figure, the array vibrator 160 includes a vibrator module 120 and a MEMS
module 161. The other configuration of the array transducer 160 is the same as that of the array
transducer 121.
[0093]
The MEMS module 161 includes the MEMS 162, the lower electrode layer 163, the backing layer
164, and the circuit chip 165. The MEMS 162 is an ultrasonic sensor formed by the MEMS, and a
specific MEMS structure is not particularly limited. The configurations of the lower electrode
layer 163, the backing layer 164 and the circuit chip 165 are the same as the configurations of
the transducer module 120. The MEMS module 161 is not limited to this configuration, as long
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as at least the MEMS 162 is provided.
[0094]
FIG. 18 is a schematic view showing the arrangement of the transducer modules 120 and the
MEMS module 161 in the array transducer 160, as viewed from the direction perpendicular to
the substrate 122. As shown in FIG. As shown in the figure, the transducer module 120 and the
MEMS module 161 are mixedly mounted on a substrate 122 to form an array. The arrangement
of the transducer module 120 and the MEMS module 161 is not limited to that shown in FIG.
[0095]
With this configuration, it is possible to use the transducer module 120 with high ultrasonic
intensity for generating ultrasonic waves and to use the MEMS module 161 with high sensitivity
for detecting reflected waves. This makes it possible to improve the ultrasonic detection
sensitivity.
[0096]
FIG. 19 is a schematic view showing a method of manufacturing the array vibrator 160. As
shown in FIG. As shown in the figure, both the transducer module 120 and the MEMS module
161 can be mounted on the substrate 122 by the pick and place method. After both modules are
mounted on the substrate 122, the filling material 127, the upper electrode layer 124, the
acoustic matching layer 125, and the acoustic lens 126 are formed in the same manner as the
array vibrator 121, and the array vibrator 160 shown in FIG. It is possible.
[0097]
[Mixed Loading of Ultrasonic Transducer and Optical Element] The transducer module 120
according to the present embodiment can also be loaded together with an optical element
module including an optical element.
[0098]
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FIG. 20 is a schematic view showing an array vibrator 170 in which a vibrator module and an
optical element module are mixedly mounted.
As shown in the figure, the array vibrator 170 includes a vibrator module 120 and an optical
element module 171. The other configuration of the array transducer 170 is the same as that of
the array transducer 121.
[0099]
The optical element module 171 includes an optical element 172, a lower electrode layer 173, a
backing layer 174, and a circuit chip 175. The optical element 172 is an element that emits light,
and is, for example, a laser diode. The configurations of the lower electrode layer 173, the
backing layer 174, and the circuit chip 175 are the same as the configurations of the transducer
module 120. The optical element module 171 is not limited to this configuration as long as it
includes at least the optical element 172.
[0100]
FIG. 21 is a schematic view showing the arrangement of the transducer module 120 and the
optical element module 171 in the array transducer 170, as viewed from the direction
perpendicular to the substrate 122. As shown in the figure, the transducer module 120 and the
optical element module 171 are mixed and mounted on the substrate 122 to form an array. The
arrangement of the transducer module 120 and the optical element module 171 is not limited to
that shown in FIG.
[0101]
With this configuration, it is possible to perform optical ultrasound imaging in which light
generated from the optical element module 171 is irradiated to a diagnosis target, and heat
generated is detected by the transducer module 120 to form an image.
[0102]
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Heretofore, it has been necessary to facilitate separate light emitting devices with optical
elements and acoustic devices with acoustic elements for optical ultrasound imaging.
According to the present technology, as described above, the ultrasonic transducers 130 and the
optical element 172 can be configured as one array, and optical ultrasonic imaging can be
realized by a single ultrasonic probe. .
[0103]
FIG. 22 is a schematic view showing a method of manufacturing the array vibrator 170. As
shown in FIG. As shown in the figure, both the transducer module 120 and the optical element
module 171 can be mounted on the substrate 122 by the pick and place method. After mounting
both modules on the substrate 122, the filling material 127, the upper electrode layer 124, the
acoustic matching layer 125, and the acoustic lens 126 are formed in the same manner as the
array vibrator 121, and the array vibrator 170 shown in FIG. It is possible.
[0104]
The array vibrator 170 may include the above-described MEMS module 161 instead of the
vibrator module 120. The array vibrator 170 can also be configured as one array of three types
of modules: the vibrator module 120, the MEMS module 161, and the optical element module
171.
[0105]
In addition to the array vibrator 160 and the array vibrator 170, any element that can be
mounted by the pick and place method can be mounted together with the vibrator module 120
and arrayed together with the vibrator module 120.
[0106]
The present technology can also be configured as follows.
[0107]
(1) An ultrasonic array vibrator comprising: an ultrasonic transducer forming an array; and a
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semiconductor chip bonded to each of the ultrasonic transducers to form an impedance matching
circuit.
[0108]
(2) The ultrasonic array vibrator according to (1), wherein the impedance matching circuit
includes an amplifier and a TR (transmit-receive) switch.
[0109]
(3) The ultrasonic array vibrator according to (1), wherein the semiconductor chip is a first
semiconductor chip provided with the amplifier, and a second semiconductor chip provided with
the TR switch. Includes ultrasonic array transducer.
[0110]
(4) The ultrasonic array vibrator according to any one of (1) to (3), wherein the semiconductor
chip is an SOI (Silicon on Insulator) chip.
[0111]
(5) The ultrasonic array vibrator according to any one of (1) to (4), wherein the ultrasonic
vibrator has a first frequency as a center frequency of vibration. An ultrasonic array transducer
comprising: an ultrasonic transducer; and a second ultrasonic transducer whose second
frequency different from the first frequency is a central frequency of vibration.
[0112]
(6) The ultrasonic array vibrator according to any one of (1) to (5), further comprising: MEMS
(Micro Electro Mechanical Systems) that constitutes an array together with the ultrasonic
vibrator. Ultrasonic array transducer.
[0113]
(7) The ultrasonic array transducer according to any one of (1) to (6), further including an optical
element forming an array with the ultrasonic transducer. .
[0114]
(8) A method of manufacturing an ultrasonic array transducer, wherein the ultrasonic transducer
to which the semiconductor chip forming the impedance matching circuit is bonded is mounted
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by a pick and place method.
[0115]
(9) In the method of manufacturing an ultrasonic array transducer according to (8), the
ultrasonic transducer is a first ultrasonic transducer whose first frequency is a central frequency
of vibration; A method of manufacturing an ultrasonic array transducer, comprising: a second
ultrasonic transducer whose center frequency of vibration is a second frequency different from
the first frequency.
[0116]
(10) The method of manufacturing an ultrasonic array transducer according to (8) or (9),
wherein the MEMS is mounted together with the ultrasonic transducer by a pick and place
method. .
[0117]
(11) The method of manufacturing an ultrasonic array transducer according to any one of (8) to
(10) above, comprising: mounting an optical element together with the ultrasonic transducer by a
pick and place method. Method of manufacturing an array transducer.
[0118]
(12) An ultrasonic probe comprising: an ultrasonic transducer constituting an array; and a
semiconductor chip joined to each of the ultrasonic vibrators to form an impedance matching
circuit.
[0119]
(13) An ultrasonic probe comprising an ultrasonic array transducer having an ultrasonic
transducer constituting an array, and a semiconductor chip joined to each of the ultrasonic
transducers and forming an impedance matching circuit, An ultrasonic diagnostic apparatus
comprising: a main body connected to a sound wave probe, supplying a drive signal to the
ultrasonic wave array transducer, and generating an ultrasonic image based on a detection signal
output from the ultrasonic wave array transducer.
[0120]
DESCRIPTION OF SYMBOLS 1 ... Ultrasonic diagnostic apparatus 11 ... Main body 12 ... Ultrasonic
probe 120 ... Transducer module 121 ... Array transducer 122 ... Substrate 123 ... Transducer
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layer 124 ... Upper electrode layer 125 ... Acoustic matching layer 126 ... Acoustic lens 127 ...
Filling material 130 ... ultrasonic transducer 131 ... piezoelectric layer 132 ... lower electrode
layer 133 ... backing layer 160 ... array transducer 161 ... MEMS module 170 ... array transducer
171 ... optical element module
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