close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JP2006174940

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2006174940
PROBLEM TO BE SOLVED: To provide an ultrasonic probe manufacturing method capable of
easily forming electrode wiring of piezoelectric vibrators arranged in large numbers and at
narrow pitches. SOLUTION: The ultrasonic probe of the present invention is a probe used for
ultrasonic diagnosis, comprising a laminated substrate in which a plurality of piezoelectric
vibrators are arranged in an array, and electrode wiring of the piezoelectric vibrators is formed. It
features. The present invention is particularly effective in an ultrasonic probe in which
piezoelectric transducers are arranged in a two-dimensional array. The probe is preferably made
of a composite piezoelectric material. [Selected figure] Figure 1
Ultrasonic probe and method of manufacturing the same
[0001]
The present invention relates to an ultrasonic probe used for an ultrasonic diagnostic apparatus
and the like and a method of manufacturing the same. In particular, the present invention relates
to an ultrasound probe that effectively functions also in ultrasound diagnosis that threedimensionally focuses and scans an ultrasound beam.
[0002]
The ultrasonic diagnostic apparatus transmits a focused ultrasonic pulse, receives a reflected
echo, scans an ultrasonic beam, and displays an image on a monitor based on the information on
13-04-2019
1
the amplitude and phase of the reflected echo. Ultrasound diagnostic devices are widely used
because they have real-time and non-invasiveness that other diagnostic devices such as CT or
MRI do not have, and also have such characteristics that blood flow dynamics can be diagnosed
based on the Doppler effect. ing.
[0003]
The ultrasonic probe used in the ultrasonic diagnostic apparatus has a structure in which
elongated rectangular parallelepiped piezoelectric vibrators are arranged in an array, and a probe
of a one-dimensional array arrangement in which the piezoelectric vibrators are arranged in one
row, in a matrix There is a probe of two dimensional array array side by side. According to the
ultrasonic probe of the two-dimensional array arrangement, a three-dimensional ultrasonic
diagnostic image can be obtained, but the piezoelectric transducers arranged on the ultrasonic
probe of the two-dimensional array arrangement form an m × n matrix form Since m and n are
required 50 or more each, the pitch between the piezoelectric transducers is 0.5 mm or less, and
the wiring drawn from the ultrasonic probe of 20 mm long × 20 mm wide is 2000 channels or
more.
[0004]
Various proposals have been made to provide an ultrasonic probe in which a large number of
piezoelectric transducers need to be arranged at a narrow pitch. For example, a signal line is
formed on one side of a printed circuit board to draw electrical wiring from the signal electrode
of the piezoelectric vibrator, a plurality of piezoelectric vibrators are mounted along one end, and
such printed circuit boards are aligned at a predetermined pitch. There is known an ultrasonic
probe which is formed and formed (see Patent Document 1). JP 2001-309493 A
[0005]
However, since this ultrasonic probe has a structure in which a large number of piezoelectric
vibrators sandwich an interconnect formed flat on a printed circuit board, the distance between
the piezoelectric vibrators is long, and the size of the ultrasonic probe itself is large. growing.
Also, the number of wires is large and crosstalk is likely to occur.
13-04-2019
2
[0006]
An object of the present invention is to provide an ultrasonic probe capable of easily forming
electrode wirings of piezoelectric vibrators arranged in a large number and narrow pitch, and a
method of manufacturing the same.
[0007]
The ultrasonic probe according to the present invention is a probe used for ultrasonic diagnosis,
and is characterized by comprising a laminated substrate in which a plurality of piezoelectric
vibrators are arranged in an array, and electrode wiring of the piezoelectric vibrators is formed.
The present invention is particularly effective in an ultrasonic probe in which piezoelectric
transducers are arranged in a two-dimensional array. The probe is preferably made of a
composite piezoelectric material.
[0008]
The laminated substrate is preferably provided with an anisotropic conductive film, and the
anisotropic conductive film is preferably made of a polytetrafluoroethylene porous film, and is
preferably provided with a through electrode. On the other hand, the anisotropic conductive film
has a columnar fine terminal oriented in the thickness direction of the film, and the fine terminal
includes a contactor at its tip connected to the electrode, and the contactor presses the electrode.
The aspect which has a spring structure which elastically deforms is preferable.
[0009]
The method of manufacturing an ultrasonic probe according to the present invention is a method
of manufacturing a probe which is used for ultrasonic diagnosis and in which a plurality of
piezoelectric transducers are arranged in an array, and by laminating a plurality of substrates. An
electrode wiring is formed.
[0010]
According to the present invention, even in the case of a two-dimensional array ultrasonic probe
in which a large number of piezoelectric vibrators are arranged at a narrow pitch, the electrode
wiring of the piezoelectric vibrators can be easily formed.
13-04-2019
3
[0011]
The ultrasonic probe of the present invention, as shown in FIG. 1A, is provided with a laminated
substrate 1 in which a plurality of piezoelectric vibrators 2a and 3a are arranged in an array and
electrode wiring of the piezoelectric vibrators 2a and 3a is formed. It is characterized by
In the example shown in FIG. 1, the laminated substrate 1 includes printed wiring boards 1 b and
1 d and an anisotropic conductive film 1 c.
The structure of the printed wiring board 1b is shown in FIG. 1 (b). The printed wiring board 1b
has an electrode 2b1 and an electrode wiring 2b2. When the laminated substrate 1 is assembled,
the electrode 2b1 is connected to the piezoelectric vibrator 2a. Therefore, signals can be
transmitted and received through the piezoelectric vibrator 2a, the electrode wiring 2b2, and the
electrode 2b1.
[0012]
The printed wiring board 1b has an electrode 3b, the anisotropic conductive film 1c has an
electrode 3c, and the printed wiring board 1d has an electrode 3d1 and an electrode wiring 3d2.
By using the electrodes 3b and 3c as through electrodes, when the laminated substrate is
assembled, the piezoelectric vibrator 3a, the electrodes 3b, 3c and 3d1 and the electrode wiring
3d2 can be conducted. Therefore, signals can be transmitted and received through the
piezoelectric vibrator 3a, the electrodes 3b, 3c, 3d1 and the electrode wiring 3d2. A solid
electrode or a hollow electrode can be used for the electrodes 3b and 3c which are through
electrodes. Although FIG. 1 shows an example in which the laminated substrate 1 of the
ultrasonic probe 10 is composed of two laminated substrates 1b and 1d and an anisotropic
conductive film 1c, a larger number of the substrates may be selected according to the number of
wires and the like. It can also be stacked.
[0013]
In the conventional method such as connecting lead wires by soldering, when the pitch between
13-04-2019
4
the piezoelectric vibrators is 0.5 mm or less and the wiring drawn from the ultrasonic probe of 2
cm long × 2 cm wide is 2000 channels or more, the wiring portion Size increases, and
productivity and quality tend to be reduced. On the other hand, according to the method of
manufacturing an ultrasonic probe of the present invention, electrode wiring of the piezoelectric
vibrator is formed by laminating a plurality of substrates, and thus electrode wiring of the
piezoelectric vibrator arranged in a large number and narrow pitch. Can be formed easily and
reliably, and compact wiring is possible. In addition, crosstalk between wires can be effectively
reduced. For this reason, it can respond also to electrode wiring of an ultrasonic probe arranged
in a two-dimensional array, and a three-dimensional ultrasonic diagnostic image can be obtained.
[0014]
FIG. 1A shows an example in which the ultrasonic probe is made of a composite piezoelectric
material. The composite piezoelectric material has a structure in which fine columnar
piezoelectric vibrators 2 a and 3 a made of piezoelectric ceramic are embedded in a resin 4. The
piezoelectric vibrators 2a and 3a have a maximum diameter when cut in a plane perpendicular to
the longitudinal direction (in the case where the cross section is circular, the diameter is referred
to). And 20 μm to 50 μm, and the length in the longitudinal direction is 40 μm to 350 μm.
The use of the composite piezoelectric material is advantageous in that the sensitivity to
ultrasonic waves can be increased.
[0015]
It is preferable that the laminated substrate has an anisotropic conductive film having
conductivity in the thickness direction of the film in terms of high cushioning properties and ease
of mounting. Although different depending on the material of the film, in general, the thickness
of the film is preferably 50 μm or more in order to obtain sufficient cushioning properties. As
such an anisotropic conductive film, a film made of a porous film made of
polytetrafluoroethylene is preferable in view of its large heat resistance, chemical stability and
voltage resistance, and low cost. In addition, the film has a through hole in the thickness
direction, and the aspect in which the plated electrode is formed on the inner surface of the
through hole is preferable because it has high cushioning properties and conductivity in the
thickness direction due to the through electrode. is there. Such films include, for example,
Poreflon (registered trademark), etc., and since this film is a flexible fiber structure porous body,
distortion in thickness is small even if contact is repeated 100,000 times or more. It is preferable
from the point that conduction can be obtained with a low load and the warp of the film is also
small.
13-04-2019
5
[0016]
For example, as shown in FIG. 3 (c), the anisotropic conductive film has columnar fine terminals
31 oriented in the thickness direction of the film, and the fine terminals 31 are contactors
connected to the electrodes at the tip. It is preferable that the contactors 31a and 31c have a
spring structure that is elastically deformed by pressing the electrodes. Since the contactor
having a spring structure elastically deforms, a reliable connection can be obtained according to
the shape of the electrode, and a large stroke can be obtained.
[0017]
The cross-sectional shape when the contactor used for an anisotropic conductive film is cut |
disconnected by a plane perpendicular | vertical to a longitudinal direction in FIG. 2 is illustrated.
2 (a) and 2 (b) are examples in which the cross-sectional shape is circular, and FIG. 2 (a) is an
example in which the spiral spring is composed of one arm. FIG. 2 (b) is an example in which the
spiral spring comprises two arms, and an embodiment having three or more arms is also
included in the present invention. In the example of FIG. 2 (b), the tips of the two arms are
connected at the center. When the plurality of arms are connected at the center in this manner,
the spring strength is increased.
[0018]
The springs illustrated in FIG. 2C and FIG. 2D have a structure in which a plurality of meandering
springs are arranged from the outer peripheral portion to the central portion of the contactor
(hereinafter referred to as “gimbal spring structure”). ). In such a spring shape, since the
current flows along the meandering spring, the generated electromagnetic fields cancel each
other, and the high frequency characteristics are good. Further, FIG. 2C shows an aspect in which
the overall shape of the contactor is circular, and three springs are not connected at the central
portion. FIG. 2D shows an aspect in which the overall shape of the contactor is square and four
springs are connected at the center. When the overall shape of the contactor is square, the area
ratio occupied by the spring increases, and the spring efficiency is improved.
[0019]
13-04-2019
6
The contactor can be manufactured by the method illustrated in FIG. まず。 As shown in FIG. 4A,
a resist 42 is formed on the conductive substrate 41. As the conductive substrate, for example, a
metal substrate made of copper, nickel, stainless steel or the like, a silicon substrate sputtered
with a metal material such as titanium, chromium or the like, or the like is used. As the resist, a
resist having a polymethacrylic acid ester such as polymethyl methacrylate (PMMA) as a main
component is used. The thickness of the resist can be arbitrarily set according to the thickness of
the contactor to be formed, and can be, for example, 50 μm to 500 μm.
[0020]
Next, a mask 43 is disposed on the resist 42, and X-rays 44 are irradiated through the mask 43.
In order to obtain a contactor with a high aspect ratio, X-rays (wavelength 0.4 nm), which have a
shorter wavelength than UV (wavelength 200 nm), are used, but because they have high
directivity among X-rays, synchrotron radiation X-rays ( Hereinafter, it is called "SR". The aspect
which uses is preferable. The mask 43 is composed of an X-ray absorbing layer 43a formed
according to the pattern of the contactor, and a translucent base 43b. Silicon nitride, silicon,
diamond, titanium or the like is used for the light-transmissive substrate 43 b. Further, for the Xray absorbing layer 43a, a heavy metal such as gold, tungsten, or tantalum or a compound
thereof is used. Of the resist 42, the resist 42a is exposed and degraded by the irradiation of the
X-ray 44, but the resist 42b is not exposed by the X-ray absorbing layer 43a. For this reason,
only the portion deteriorated by the X-ray 44 is removed by development, and a resist 42b as
shown in FIG. 4B is obtained.
[0021]
Next, electroforming is performed, and as shown in FIG. 4C, a metal material 45a is deposited on
the resist 42b. Electroforming refers to forming a layer made of a metal material on a conductive
substrate using a metal ion solution. By electroforming using the conductive substrate 41 as a
plating electrode, the metal material 45a can be deposited on the resist 42b. As the metal
material, nickel, copper, or alloys thereof are used, and in view of enhancing the wear resistance
of the contactor, nickel or nickel alloy such as nickel manganese is preferable.
[0022]
13-04-2019
7
After electroforming, the resist 42b is removed by wet etching or plasma etching as shown in
FIG. 4 (e) after being equalized to a predetermined thickness by polishing or grinding (FIG. 4 (d)).
Subsequently, wet etching with an acid or alkali, or mechanical processing to remove the
conductive substrate 41, a metal microstructure 45 as shown in FIG. 4 (f) is obtained. Next, a
contactor can be obtained by performing a heat treatment at 150 ° C. to 350 ° C. for 2 hours
to 48 hours to impart spring characteristics. The obtained contactor is provided with a gold coat
of 0.05 μm to 1 μm in thickness as needed in order to enhance the electrical conductivity with
an electrode of an electronic device or the like.
[0023]
Next, a method for producing an anisotropic conductive film from the obtained contactor is
illustrated in FIG. First, as shown in FIG. 3A, through holes are formed in the film 32 at positions
corresponding to the piezoelectric vibrators of the probe to be mounted in accordance with the
outer diameter of the contactor to be accommodated. Subsequently, similarly, the lower lid sheet
33 in which a hole smaller than the outer diameter of the contactor to be accommodated is
formed at a position corresponding to the arrangement of the piezoelectric vibrator is laminated
to the film 32.
[0024]
Thereafter, as shown in FIG. 3B, the contactor 31c, the ring 31b, and the contactor 31a are fitted
in this order in the through holes of the film 32. The ring 31b is added to provide a space in
which the contactors 31a, 31c can stroke without contacting when pressed against the
electrodes. The ring 31b is a metal fine structure similar to the contactors 31a and 31c, and thus
can be manufactured by the same method as the contactor. Thereafter, when the upper lid sheet
34 similar to the lower lid sheet 33 is attached to the film 32, an anisotropic conductive film as
shown in FIG. 3C is obtained. The film 32, the lower lid sheet 33 and the upper lid sheet 34 are
formed of a material having electrical insulation, such as a polyimide resin or a general fiber
reinforced resin (FRP).
[0025]
Example 1 A probe made of a composite piezoelectric material was manufactured by the method
13-04-2019
8
shown in FIG. First, as shown in FIG. 5A, a resist 52 for lithography was formed on a conductive
substrate 51. As a conductive substrate, a silicon substrate sputtered with Ti was used. For the
resist, polymethyl methacrylate was used, and the thickness of the resist was 300 μm. Next, the
mask 53 was placed on the substrate 51, and SR was irradiated to the resist 52 through the mask
53. As the mask 53, a mask obtained by forming an X-ray absorbing layer 53a made of tungsten
on a translucent base made of silicon nitride was used.
[0026]
The exposed resist was developed, and the portion altered by SR was removed to obtain a resist
54 as shown in FIG. 5 (b). Thereafter, as shown in FIG. 5C, a metal mold 55 made of nickel was
formed on the resist 54 by electroforming. Subsequently, the substrate 51 was removed by wet
etching, the resist 54 was removed by plasma etching, and the mold 55 was taken out. Next, as
shown in FIG. 5 (d), a resin mold 56 made of polymethyl methacrylate was prepared by using a
mold 55, and then the resin mold 56 was taken out except for the mold 55.
[0027]
Thereafter, as shown in FIG. 5E, the resin mold 56 was filled with a slurry 57 containing ceramic
particles of lead zirconate titanate (PZT), dried and solidified. Thereafter, the resin mold 56 is
removed, and the dried and solidified product of the ceramic slurry is fired to obtain a
microstructure 58 made of a ceramic sintered body as shown in FIG. 5 (f). Subsequently, as
shown in FIG. 5 (g), an epoxy resin 59 was filled and cured. Finally, the pedestal portion and the
top surface of the fine structure 58 were polished to obtain an ultrasonic probe 50 made of a
composite piezoelectric material.
[0028]
The probe 50 was 20 mm long × 20 mm wide, and each piezoelectric vibrator on the probe was
cylindrical, 35 μm in diameter, and 250 μm in height. This piezoelectric vibrator was formed
400 vertical by 400 horizontal (total 160000), and the electrode pitch was 200 μm in both
vertical and horizontal directions, and it was an ultrasonic probe of a two-dimensional array
arrangement. A conductive resin film was attached to one side of the obtained probe as a
common ground electrode, and a matching layer and a resin acoustic lens were attached to the
common ground electrode. The matching layer was for acoustic matching, and was made of an
13-04-2019
9
epoxy resin filled with W powder.
[0029]
On the other surface of the probe, as shown in FIG. 1, the laminated substrate 1 was formed for
the electrode wiring of the piezoelectric vibrator (in FIG. 1, one of the probe and the laminated
substrate 1 for clarity of the figure. Show only the department). The laminated substrate 1 is
composed of two printed wiring boards 1b and 1d, and includes an anisotropic conductive film
1c between the substrates. Predetermined electrodes 2b1, 3b, 3d1 and electrode wires 2b2, 3d2
are formed on the printed wiring boards 1b, 1d, corresponding to the piezoelectric vibrators in
the probe. The anisotropic conductive film 1c is a porous film made of polytetrafluoroethylene
(Poreflon (registered trademark) made by Sumitomo Electric Industries, Ltd.) having a thickness
of 100 μm, and the through electrode 3c is formed according to the piezoelectric vibrator of the
attached probe did. The through electrode 3 c was formed by forming a through hole with a hole
diameter of 30 μm in the film, and plating the inner wall of the through hole with Au.
[0030]
In this embodiment, since the electrode wiring of the piezoelectric vibrator is formed by
laminating a plurality of substrates without using the conventional solder connection using the
lead wire, the wiring structure can be made compact. In addition, the wiring operation can be
easily performed, the wiring quality of the obtained ultrasonic probe is good, and crosstalk is not
recognized.
[0031]
It should be understood that the embodiments and examples disclosed herein are illustrative and
non-restrictive in every respect. The scope of the present invention is indicated not by the above
description but by the claims, and is intended to include all the modifications within the meaning
and scope equivalent to the claims.
[0032]
A two dimensional array array of ultrasound probes can be easily provided to obtain a three
dimensional ultrasound diagnostic image.
13-04-2019
10
[0033]
It is a perspective view which shows the structure of the ultrasonic probe of this invention.
It is sectional drawing of the contactor used for the laminated substrate of the ultrasonic probe of
this invention. It is process drawing which shows the manufacturing method of the anisotropic
conductive film used for the ultrasonic probe of this invention. It is process drawing which shows
the manufacturing method of the contactor used for the laminated substrate of the ultrasonic
probe of this invention. It is process drawing which shows the manufacturing method of the
probe which consists of composite piezoelectric material in this invention.
Explanation of sign
[0034]
DESCRIPTION OF SYMBOLS 1 Multilayer board | substrate, 1b, 1d printed wiring board, 1c
Anisotropic conductive film, 2a, 3a piezoelectric vibrator, 2b1, 3b, 3c, 3d1 electrode, 2b2, 3d2
electrode wiring, 10 ultrasonic probe.
13-04-2019
11
Документ
Категория
Без категории
Просмотров
0
Размер файла
22 Кб
Теги
description, jp2006174940
1/--страниц
Пожаловаться на содержимое документа