U.S. patent application number 14/137578 was filed with the patent office on 2014-04-17 for ultrasonic transducer and fabricating the same.
This patent application is currently assigned to Kabushiki Kaisha Toshiba. The applicant listed for this patent is Kabushiki Kaisha Toshiba. Invention is credited to Satoru Asagiri, Takeshi Miyagi, Michiko Ooishi, Takashi TOGASAKI.
Application Number | 20140103782 14/137578 |
Document ID | / |
Family ID | 45351857 |
Filed Date | 2014-04-17 |
United States Patent
Application |
20140103782 |
Kind Code |
A1 |
TOGASAKI; Takashi ; et
al. |
April 17, 2014 |
ULTRASONIC TRANSDUCER AND FABRICATING THE SAME
Abstract
An aspect of one embodiment, there is provided an ultrasonic
transducer including a plurality of oscillators, each of the
oscillator having a convex portion, a printed wiring board provided
to be opposed to the convex portion and electrically connected to
the convex portion, a resin provided between the oscillator and the
printed wiring board, the resin covering at least the convex
portion and a portion of the printed wiring board.
Inventors: |
TOGASAKI; Takashi;
(Kanagawa-ken, JP) ; Miyagi; Takeshi;
(Kanagawa-ken, JP) ; Asagiri; Satoru;
(Kanagawa-ken, JP) ; Ooishi; Michiko;
(Kanagawa-ken, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kabushiki Kaisha Toshiba |
Minato-ku |
|
JP |
|
|
Assignee: |
Kabushiki Kaisha Toshiba
Minato-ku
JP
|
Family ID: |
45351857 |
Appl. No.: |
14/137578 |
Filed: |
December 20, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13167276 |
Jun 23, 2011 |
|
|
|
14137578 |
|
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Current U.S.
Class: |
310/334 ;
29/25.35 |
Current CPC
Class: |
H01L 41/22 20130101;
G10K 9/125 20130101; B06B 1/0622 20130101; Y10T 29/49005 20150115;
Y10T 29/42 20150115 |
Class at
Publication: |
310/334 ;
29/25.35 |
International
Class: |
B06B 1/06 20060101
B06B001/06; H01L 41/22 20060101 H01L041/22; G10K 9/125 20060101
G10K009/125 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 23, 2010 |
JP |
2010-143167 |
Jun 21, 2011 |
JP |
2011-137705 |
Claims
1. (canceled)
2. An ultrasonic transducer, comprising: a plurality of
oscillators, each of the oscillator having a convex portion; a
printed wiring board provided to be opposed to the convex portion
and electrically connected to the convex portion; a resin provided
between the oscillator and the printed wiring board, the resin
covering at least the convex portion and a portion of the printed
wiring board.
3. The ultrasonic transducer of claim 2, wherein the oscillator
includes a transducer element including an acoustic matching layer,
a piezoelectric element and a backing member in order as a stacked
body, a first electrode on the packing member and a second
electrode on the acoustic matching layer, and the convex portion
includes the first electrode and the backing member.
4. The ultrasonic transducer of claim 2, wherein the oscillator
includes the transducer element including the acoustic matching
layer, the piezoelectric element and the backing member in order as
the stacked body, the first electrode on the backing member and the
second electrode on the acoustic matching layer, and the convex
portion is provided on the first electrode.
5. The ultrasonic transducer of claim 2, further comprising: an
adhesive material contacted to cover at least a portion of the
convex portion, the adhesive material connecting the oscillator and
the printed wiring board, wherein the resin is provided to cover at
least a portion of the adhesive material.
6. A method of fabricating the ultrasonic transducer according to
claim 2, comprising: providing the plurality of the convex portions
on a oscillation body; aligning to electrically connect each of the
convex portions with the printed wiring board; providing a resin
between the oscillation body and the printed wiring board; and
dividing the oscillation body into the plurality of
oscillators.
7. The method of claim 6, wherein the resin covers at least each of
the convex portions and a portion of the printed wiring board in
the providing of the resin.
8. The method of claim 6, wherein the oscillation body includes an
acoustic matching layer, a piezoelectric element and a backing
member in order as the stacked body, and a first electrode is
provided on the backing member and the second electrode is provided
on the acoustic matching layer, and the backing member is diced in
the providing of the convex portion.
9. The method of claim 6, wherein the oscillation body includes the
acoustic matching layer, the piezoelectric element and the backing
member in order as the stacked body, and the first electrode is
provided on the backing member and the second electrode is provided
on the acoustic matching layer, and a conductive bump is formed on
the first electrode in the providing of the convex portion.
10. The method of claim 6, further comprising: providing an
adhesive material at a position on which the convex portion is
provided on the printed wiring board.
11. The method of claim 6, wherein dicing a portion of the resin
between the oscillation body and the printed wiring board in the
dividing of the oscillation body.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional application of U.S.
application Ser. No. 13/167,276, filed Jun. 23, 2011, which claims
priority from prior Japanese Patent Application No. 2010-143167,
filed on Jun. 23, 2010, and Japanese Patent Application No.
2011-137705, filed on Jun. 21, 2011. The entire contents of the
above-identified applications are incorporated herein by
reference.
FIELD
[0002] Exemplary embodiments described herein generally relate to
an ultrasonic transducer and a method of fabricating the ultrasonic
transducer.
BACKGROUND
[0003] An ultrasonic transducer, for example, has been used as an
ultrasonic probe of an ultrasonograph. The ultrasonic transducer in
the ultrasonograph carries ultrasonic waves to an object under test
and receives reflection waves from the object under test. Recently,
an ultrasonic transducer with higher accuracy inspection has been
utilized. In this ultrasonic transducer, piezoelectric elements are
arranged in a two-dimension array.
[0004] As shown in FIG. 9, in an ultrasonic transducer 101, for
example, a conductive element 111 and an adhesive material 112 are
provided between an oscillator 105 and an IC substrate 108 to
connect the oscillator 105 and the IC substrate 108.
[0005] The oscillator 105 includes a plurality of transducer
elements 102, a first electrode 103 and a second electrode 104. The
transducer elements 102 are arranged in a prescribed matrix. The
first electrode 103 and the second electrode 104 are arranged on
two surfaces opposed each ether of the transducer element 102,
respectively. Further, in the IC substrate 108, an integrated
circuit 107 is provided on a substrate body 106, and a
redistribution layer 110 including a conductive body 109 is
provided on the integrated circuit 107.
[0006] A method of fabricating the ultrasonic transducer 101 is
described below.
[0007] After the conductive element 111 is provided on the
conductor 109 of the IC substrate, the adhesive material 112 is
provided. An oscillation body (not shown) in which the oscillators
105 are serially connected joined on the conductive element 111.
The oscillation body is divided into the oscillators. Dicing is
performed to a surface of the second electrode in dividing, and the
transducer elements 102 and the second electrode 104 are cut by
using laser.
[0008] In the situation mentioned above, an ultrasonic transducer
having higher reliability and a method of fabricating the above
ultrasonic transducer have been desired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view showing an ultrasonic
transducer in a first embodiment.
[0010] FIG. 2 is a cross-sectional view showing the ultrasonic
transducer enlarged along the line A-A of FIG. 1 in the first
embodiment.
[0011] FIGS. 3A-3C are cross-sectional views showing a method of
fabricating the ultrasonic transducer in the first embodiment.
[0012] FIGS. 4A-4C are cross-sectional views showing the method of
fabricating the ultrasonic transducer in the first embodiment.
[0013] FIGS. 5A-5D are cross-sectional views showing the method of
fabricating the ultrasonic transducer in the first embodiment.
[0014] FIG. 6 is a cross-sectional view showing an ultrasonic
transducer in a second embodiment.
[0015] FIGS. 7A-7B are cross-sectional views showing a method of
fabricating the ultrasonic transducer in the second embodiment.
[0016] FIGS. 8A-8D are cross-sectional views showing the method of
fabricating the ultrasonic transducer in the second embodiment.
[0017] FIG. 9 is a cross-sectional view showing an ultrasonic
transducer in conventional technology.
DETAILED DESCRIPTION
[0018] An aspect of one embodiment, there is provided an ultrasonic
transducer including a plurality of oscillators, each of the
oscillator having a convex portion, a printed wiring board provided
to be opposed to the convex portion, an adhesive material including
at least a portion of the convex portion, the adhesive material
joining the oscillator and the printed wiring board, and a resin
provided between the oscillator and the printed wiring board, the
resin covering the convex portion and the adhesive material.
[0019] An aspect of another embodiment, there is provided a method
of fabricating the ultrasonic transducer mentioned above including
providing a plurality of convex portions on a oscillation body,
providing the adhesive material with conductivity on a plurality of
positions on the printed wiring board, each of the convex portions
being provided in each of the positions, joining the convex portion
on the oscillation body and the printed wiring board in a state
with being aligning each other, providing the resin between the
oscillation body and the printed wiring board, and dividing the
oscillation body into a plurality of oscillators.
[0020] Embodiments on an ultrasonic transducer and a method of
fabricating the ultrasonic transducer will be described below in
detail with reference to the attached drawings mentioned above.
Throughout the attached drawings, similar or same reference
numerals show similar, equivalent or same components.
First Embodiment
[0021] An ultrasonic transducer 1 in the first embodiment is
described using FIG. 1 and FIG. 2 as a reference. As shown in FIG.
1, an ultrasonic transducer 1 includes an adhesive material 4 and a
resin 5 between a plurality of oscillators 2 and a printed wiring
board 3.
[0022] As shown in FIG. 2, each of the oscillators 2 is constituted
with a transducer element 7 with a convex portion 6, a first
electrode 8 and a second electrode 9. The oscillators 2 are
provided as a matrix. In this embodiment, for example, the matrix
is arranged with about one hundred in the longitudinal direction
and forty in the other direction crossed to the longitudinal
direction. On the other hand, a number of the oscillator 2, an
arrangement on the oscillators 2 or the like cannot be restricted
to the above case. For simplicity, the matrix in FIG. 1 is
constituted with about thirty-one in the longitudinal direction and
ten in the other direction crossed to the longitudinal direction.
FIG. 2 is a cross-sectional view in which the oscillators 2 are
partially omitted.
[0023] An acoustic matching layer 10, the transducer element 7
includes a piezoelectric element 11 and a backing member in order
as a stacked body. The convex portion 6 is constituted with the
backing member 12
[0024] The acoustic matching layer 10 matches acoustic impedance
between the piezoelectric element 11 and an object under test (not
shown). First, the piezoelectric element 11 translates an
electrical signal into an ultrasonic pulse, and carries the
ultrasonic pulse to the object under test. The object under test
reflects the ultrasonic pulse to return the acoustic matching layer
10. The acoustic matching layer 10 receives the ultrasonic pulse,
and translates into an electrical signal to output.
[0025] The backing member 12 absorbs a portion of the ultrasonic
pulse which is emitted to the opposite side to the irradiation
direction of the ultrasonic pulse when the ultrasonic pulse is
carried by the piezoelectric element 11. Accordingly, the backing
member 12 can control excess vibration of the piezoelectric element
11.
[0026] Each of the convex portions 6 is formed as nearly the same
height and has narrower width than the oscillator 2. In this
embodiment, the convex portion 6 is formed by the backing member
12. The summit of the convex portion 6 includes nearly a flat
surface, and each of four side surfaces of the convex portion 6
includes a step. Further, the summit of the convex portion 6 can be
inserted into the adhesive material 4 and has a narrower region
than that of the adhesive material 4 to strengthen the connection
between the convex portion 6 and the adhesive material 4. On the
other hand, the shape of convex portion 6 is not restricted to the
above case. The shape of convex portion 6 can be provided as a
shape which is be able to insert the summit of the convex portion 6
into adhesive material 4. For example, a shape with a plurality of
steps, a columnar shape without steps such as a pillar, a triangle
pole, a cylinder, a circular cone, a pyramid or the like can be
utilized.
[0027] The first electrode 8 in this embodiment is provided on
nearly flat plane of the summit of the convex portion in transducer
element 7. The second electrode 9 is provided to cover a surface
side opposed to the side in which the convex portion 6 is provided.
The first electrode 8 is provided on the nearly flat plane of the
summit of the convex portion 6 in FIG. 2. On the other hand, the
first electrode 8 is not restricted to the above case. The first
electrode 8 can be formed on surfaces of the convex portion 6 in
the condition of including the summit of the convex portion 6.
[0028] Titanium (Ti) and gold (Au) in order are stacked in the
first electrode 8 in this embodiment. As another case, nickel (Ni)
and Au in order can be stacked in the first electrode 8 in this
embodiment. On the other hand, the stacking order, a layer number
or materials in the stacked layer are not restricted to the above
case. In the second electrode 9, for example, Ti and Au in order
are stacked in the second electrode 9 in this embodiment. On the
other hand, the stacking order, a layer number or materials in the
stacked layer is not restricted to the above case.
[0029] The printed wiring board 3 is provided on a surface side
opposed to the surface of the first electrode 8 in the oscillator
2. The printed wiring board 3 is connected to a conductor 14
stacked on a printed wiring board 13. Each of the pads 15 is
provided at a position corresponding to each of the convex portion
6. A solder resist 16 is provided to surround the pads 15.
[0030] Copper (Cu), nickel (Ni) and gold in order, for example, are
stacked in the pad 15. On the other hand, the stacking order, a
layer number or materials of the stacked layer is not restricted to
the above case. An area of the pad 15 is slightly larger than a
portion connected to the adhesive material 4.
[0031] The adhesive material 4 is provided between the convex
portion 6 of the oscillator 2 and the pad 15 of the printed wiring
board 3. The adhesive material 4 contacts to cover at least a
portion of the convex portion 6, and connects to the oscillator 2
and the printed wiring board 3.
[0032] In this embodiment, a metal filler and a thermosetting
resin, for example, including a silver (Ag) filler and an epoxy
resin, respectively, are utilized as a material for the adhesive
material 4. On the other hand, the material for the adhesive
material 4 is not restricted to the above case. A material
including a solder, both a solder and a thermosetting resin or the
like which can electrically connect between the oscillator 2 and
the printed wiring board 3 can be utilized.
[0033] The resin 5 surrounds the convex portion 6 and the adhesive
material 4, and is filled between the oscillator 2 and the wiring
substrate 3. A thermosetting resin with 50 ppm or below 50 ppm in
thermal expansion coefficient, for example, an epoxy resin is
utilized as the material in this embodiment. On the other hand, the
material is not restricted to the above case. The same material as
the material of resin used as the adhesive material 4 can obtain a
reliable connection due to improvement of adhesiveness.
[0034] A method of fabricating the ultrasonic transducer 1 is
described with reference to FIG. 3, FIG. 4 and FIG. 5.
[0035] The method of fabricating the ultrasonic transducer 1 is
divided into three processes as a large classification. The first
process is providing the convex portion 6 on an oscillation body
20, the second process is providing the adhesive material 4 on the
printed wiring board 3, and the third process is connecting between
the oscillation body 20 and the printed wiring board 3 and dividing
the oscillation body 20. Furthermore, the oscillation body 20 means
a state before dividing into the oscillators 2. Therefore, the
oscillation body 20 has the same constitution with the oscillator
2.
[0036] Processing steps of providing the convex portion 6 on the
oscillation body 20 is explained below using FIG. 3 as the
reference.
[0037] As shown in FIG. 2A, the first electrode 8 and the second
electrode 9 are provided on a side of the backing member and a side
of the acoustic matching layer 10 in the transducer element 7,
respectively.
[0038] Ti, Au and Ti are stacked in order as the first electrode 8
in this embodiment. Ti and Au are stacked in order as the second
electrode 9. As a method of forming the metals, for example,
sputtering, electro-plating or the like can be utilized. The
materials and the orders constituted with the first electrode 8 and
the second electrode 9 is not restricted to the above case. Those
conditions mentioned above can be suitably selected.
[0039] As shown in FIG. 2B, a first dicing step is carried out.
[0040] The first dicing step is performed to the backing member 12.
In the first dicing step, a plurality of blades 21 is utilized.
Each of the blades 21 has a thickness of nearly 50 .mu.m and the
blades 21 are provided with nearly 200 .mu.m pitch. The thickness
and the pitch of each of the blades 21 are not restricted to the
above cases. The blade with desirable thickness and pitch can be
used. Cutting in the first dicing step in this embodiment is
repeated five times with an interval of nearly 25 .mu.m. The
interval is set corresponding to a half of the thickness of the
blade 21. As a result, a depth and a groove width are nearly 90
.mu.m and 150 .mu.m, respectively. The depth and the width and the
shifting distance of the blade 21 and a number of the cutting are
not restricted to the above case, further, can be suitably
selected.
[0041] As shown in FIG. 3C, a second dicing step is carried
out.
[0042] The groove formed in first dicing step is further cut in the
second dicing step. The same blade 21 used in the first dicing step
is also utilized in the second dicing step. The center portion of
the groove is cut to be the depth of nearly 50 .mu.m and the groove
width of nearly 50 .mu.m by one dicing step. The same blade 21 used
in the first dicing step is used in this embodiment. On the other
hand, the blade 21 is not restricted to the above case, but can be
used as a different case. Further, the depth and the width of the
groove can be changed.
[0043] After the processing steps mentioned above, next dicing step
is carried out along the perpendicular direction to the diced
direction as the same method described in FIGS. 2B and 2C. In such
a manner, the convex portion 6 is provided. The convex portion 6
has an area of the summit being 50.times.50 .mu.m.sup.2 and an area
of the bottom portion being 150.times.150 .mu.m.sup.2.
[0044] In this embodiment, the process is a case in which one step
is provided. On the other hand, the process is not restricted to
the above case. In a case that a shape with a plurality of steps is
desirable, further dicing can be performed to form a step or a
plurality of steps. In a case that a shape with a columnar shape
without steps such as a pillar, a triangle pole, a cylinder, a
circular cone, a pyramid or the like can be utilized, the
processing steps can be decreased. In such a manner, as the convex
portion is provided by dicing the backing member 12 of the
oscillation body 20 with a constant thickness, variations in the
height can be suppressed.
[0045] Process steps of providing the adhesive material 4 on the
printed wiring board 3 is explained below using FIG. 4 as the
reference.
[0046] As shown in FIG. 4A, a mask 22 is disposed on the wiring
substrate 3.
[0047] Cu, Ni and Au are stacked in order on the pad 15 in the
printed wiring board 3 in this embodiment. The mask 22 includes
holes 23 which are aligned with the pad 15 in the printed wiring
board 3. An area of each of the holes 23 is slightly smaller than
that of the pad 15.
[0048] As shown in FIG. 4B, the adhesive material 4 is filled into
the hole 23 of the mask 22 by shifting a squeegee 24.
[0049] As shown in FIG. 4C, mask 22 is removed. In such a manner,
the hole 23 is formed as smaller than the pad 15, and the adhesive
material 4 is filled in the hole 23. In joining the printed wiring
board 3 and the oscillation body 20 mentioned after, the adhesive
material 4 overflows to extend to another pad or the like. As a
result, generation of leakage current can be suppressed.
[0050] Process steps of joining between the oscillation body 20 and
the printed wiring board 3 and dividing the oscillation body 20
into oscillators 2 are explained below using FIG. 5 as the
reference.
[0051] As shown in FIG. 5A, the oscillation body 20 is mounted on
the printed wiring board 3. In the step, the convex portion 6 of
the oscillation body 20 is inserted about 90 .mu.m into the
adhesive material 4, so that the convex portion 6 is joined to the
adhesive material 4. On the other hand, the joining is not
restricted to the above case. A portion of the convex portion 6 can
be exposed to be inserted into the adhesive material 4.
[0052] In performing such joining, a distance between the printed
wiring board 3 and the oscillation body 20 can be extended.
Accordingly, dicing into the printed wiring board 3 can be
suppressed when the oscillation body 20 is divided into the
oscillators 2 mentioned after. As the convex portion 6 is inserted
into the adhesive material 4, a contact area can be widened, so
that connection with higher strength can be performed. Variations
in the height of the convex portions 6 can be substantially less
influenced as the insertion, so that electrical connection can be
performed.
[0053] As shown in FIG. 5B, the resin 5 is filled between the
oscillation body 20 and the printed wiring board 3. In the
processing step, the resin 5 is underfill-coated by using a
dispenser 25, so that the resin 5 is filled in a space between the
oscillation body 20 and the wiring substrate 3 by capillary.
[0054] As shown in FIG. 5C, the adhesive material 4 and resin 5 are
heated to cure in heating equipment 26, for example. After about
ten minutes passes from finishing filling the resin 5 for removing
bubbles from the resin 5, the heat treatment is performed at about
150.degree. C. during 4 hours. In the above case, silver filler and
epoxy resin are used as the adhesive material 4 in this embodiment.
When silver filler and epoxy resin including solder is used as the
adhesive material 4, heat treatment is performed at about
240.degree. C. during 30 seconds. Left time after filling the resin
5, heating temperature and time are not restricted to the above
cases, and can be suitably selected.
[0055] As shown in FIG. 5D, the oscillation body 20 is diced by
using the blade 21 with a thickness of about 50 .mu.m. Nearly
central portion of adjacent convex portions 6 is set as the dicing
position and is diced along a direction to form the oscillators 2
as a matrix. Successively, next dicing is carried out along the
perpendicular direction to the diced direction. The resin 5 is also
diced slightly to cut the oscillation body 20 accurately.
[0056] According to the first embodiment, each of the convex
portions 6 is provided in a prescribed interval fashion on the
backing member 12, and a portion of the convex portion 6 is
inserted into the adhesive material 4 on the printed wiring board 3
to join the convex portions 6 with the adhesive material 4.
[0057] In such a manner, as the convex portion 6 is composed of the
backing member 12, the height of the convex portion 6 can be nearly
uniformed by forming the convex portion 6 in the backing member 12.
Furthermore, as the portion of the convex portion 6 is included
with the adhesive material 4 in the mounting process, the distance
between the printed wiring board 3 and the oscillation body 20 can
be extended, and dicing into the printed wiring board 3 can be
suppressed. Consequently, highly reliable transducer can be
obtained. Further, the contact area is widened due to inserting the
convex portion 6 into the adhesive material 4 in connection, so
that high strength connection with retaining electrical connection
can be performed in the dicing process. Therefore, further highly
reliable transducer can be obtained.
[0058] In the embodiment mentioned above, the dicing step is
carried out after the first electrode 8 and the second electrode 9
are provided. On the other hand, the second electrode 9 is provided
in first, and the first electrode 8 can be provided after the
convex portion 6 is provided.
Second Embodiment
[0059] An ultrasonic transducer in the second embodiment is
described below in detail with reference to the attached drawings
FIGS. 6, 7 and 8 mentioned above. It is different from the first
embodiment that each of convex portions 32 is provided on each of
oscillators 31. On the other hand, another component in the second
embodiment other than the different point is the same as that in
the first embodiment. Accordingly, an ultrasonic transducer 30
including the convex portion 32 which is different from the first
embodiment and a method of fabricating the ultrasonic transducer 30
are demonstrated in FIGS. 6, 7 and 8 in this embodiment.
[0060] As shown in FIG. 6, the convex portion 32 in the ultrasonic
transducer 30 is provided on the oscillator 31 in this embodiment.
The oscillator 31 is constituted with a transducer element 33, a
first electrode 8 and a second electrode 9.
[0061] The transducer element 33 includes an acoustic matching
layer 10, a piezoelectric element 11 and a backing member 34 in
order as a stacked body. The first electrode 8 and the second
electrode 9 are provided on both surfaces of the transducer element
33 corresponding to each other in the longitudinal direction of the
transducer element 33.
[0062] A plurality of the convex portions 32 are provided on the
first electrode 8, and each of the convex portions 32 is set in a
prescribed interval. The convex portion 32 is composed of a
conductive bump including gold (Au), solder or the like, for
example.
[0063] The method of fabricating the ultrasonic transducer 30 is
described below with reference to FIG. 7 and FIG. 8.
[0064] The method of fabricating the ultrasonic transducer 30 is
divided into three processes as a large classification. The first
process is providing the convex portion 32 on an oscillation body
35, the second process is providing the adhesive material 4 on the
printed wiring board 3, and the third process is joining between
the oscillation body 35 and the printed wiring board 3 and dividing
the oscillation body 35. Furthermore, the oscillation body 35 means
a state before dividing into the oscillator 31. Therefore, the
oscillation body 35 has the same constitution as the oscillator 31.
The process of providing the adhesive material 4 on the wiring
substrate 3 is the same as the first embodiment, so that the
explanation is omitted.
[0065] Process steps of providing the convex portion 32 on the
oscillation body 35 is explained below using FIG. 3 as the
reference.
[0066] As shown in FIG. 7A, the first electrode 8 and the second
electrode 9 are provided on a side of the backing member and a side
of the acoustic matching layer 10 in the transducer element 33,
respectively.
[0067] Ti, Au and Ti are stacked in order in the first electrode 8,
and Ti and Au are stacked in order in the second electrode 9. As a
method of forming the metals, for example, sputtering,
electro-plating or the like can be utilized.
[0068] As shown in FIG. 7B, a bump material is provided on the
first electrode 8. The bump material is provided by using
wire-bonding. An amount of the bump material to form the convex
portion 32 is provided.
[0069] Process steps of joining between the oscillation body 35 and
the wiring substrate 3 and dividing the oscillation body 35 into
oscillators 31 are explained below using FIG. 8 as the
reference.
[0070] As shown in FIG. 8A, the oscillation body 35 is mounted on
the printed wiring board 3. In the step, at least a portion of the
convex portion 32 of the oscillation body 35 is exposed to be
inserted into the adhesive material 4 on the printed wiring board
3, so that the convex portion 32 is joined to the adhesive material
4.
[0071] In performing such joining, a distance between the printed
wiring board 3 and the oscillation body 35 can be extended.
Accordingly, dicing into the printed wiring board 3 can be
suppressed when the oscillation body 35 is divided into the
oscillators 31 mentioned after. As the convex portion 6 is inserted
into the adhesive material 4, a contact area can be widened so that
connection with higher strength can be performed. Variations in the
height of the convex portions 6 can be substantially less
influenced as the insertion, so that electrical connection can be
performed.
[0072] As shown in FIG. 8B, a resin 5 is filled between the
oscillation body 35 and the printed wiring board 3. In the steps,
the resin 5 is underfill-coated by using a dispenser 25, so that
the resin 5 is filled in a space between the oscillation body 35
and the printed wiring board 3 by capillary.
[0073] As shown in FIG. 8C, the adhesive material 4 and the resin 5
are heated to cure in heating equipment 26 for example. After about
ten minutes passes from finishing filling the resin 5 for removing
bubbles in the resin, the heat treatment is performed at about
150.degree. C. during 4 hours. In the above case, silver filler and
epoxy resin are used as the adhesive material 4 in this embodiment.
When silver filler and epoxy resin including solder is used as the
adhesive material 4, heat treatment is performed at about
240.degree. C. during 30 seconds. Left time after filling the resin
5, heating temperature and time are not restricted to the above
cases, and can be suitably selected.
[0074] As shown in FIG. 8D, the oscillation body 35 is diced by
using a blade 21 with a thickness of about 50 .mu.m. Nearly central
portion of adjacent convex portions 6 is set as the dicing
position. Successively, next dicing is carried out along the
perpendicular direction to the diced direction. The resin 5 is also
diced slightly to cut the oscillation body 35 accurately.
[0075] According to the second embodiment, each of the convex
portions 32 is provided in a prescribed interval fashion on the
oscillator 31, and a portion of the convex portion 32 is inserted
into the adhesive material 4 on the printed wiring board 3 to join
the convex portions 6 with the adhesive material 4.
[0076] In such a manner, at least a portion of the convex portion 6
is inserted to be included in the adhesive material 4, so that the
convex portion can be mounted. Consequently, the distance between
the printed wiring board 3 and the oscillation body 20 can be
extended, and dicing into the printed wiring board 3 can be
suppressed. Further, variations in the height of the convex
portions 6 can be substantially less influenced as the insertion,
so that electrical connection can be performed. Consequently,
highly reliable transducer can be obtained. Further, the contact
area is widened due to inserting the convex portion 6 into the
adhesive material 4 in connection, so that higher strength
connection with retaining electrical connection can be performed in
the dicing process. Therefore, further highly reliable transducer
can be obtained.
[0077] Other embodiments of the present disclosure will be apparent
to those skilled in the art from consideration of the specification
and practice of the disclosure disclosed herein. It is intended
that the specification and example embodiments be considered as
exemplary only, with a true scope and spirit of the disclosure
being indicated by the claims that follow. The disclosure can be
carried out by being variously modified within a range not deviated
from the gist of the disclosure.
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