U.S. patent application number 13/128759 was filed with the patent office on 2011-09-08 for body with magnetic film attached and manufacturing method therefor.
Invention is credited to Koichi Kondo, Yukihiro Numata, Hiroshi Ono.
Application Number | 20110217531 13/128759 |
Document ID | / |
Family ID | 42016867 |
Filed Date | 2011-09-08 |
United States Patent
Application |
20110217531 |
Kind Code |
A1 |
Kondo; Koichi ; et
al. |
September 8, 2011 |
BODY WITH MAGNETIC FILM ATTACHED AND MANUFACTURING METHOD
THEREFOR
Abstract
A fabrication method for fabricating a magnetic film provided
body includes preparing a base body and forming a magnetic film on
the base body. The magnetic film includes organic film(s) and
ferrite film(s) alternately layered. The formation of the magnetic
film alternately includes forming a ferrite film through a ferrite
plating method, the ferrite film having a thickness of 20 .mu.m or
less, and forming an organic film having a thickness of 0.1 .mu.m
to 20 .mu.m, both inclusive, and a ratio t/E of 0.025 .mu.m/GPa or
more, where "t" indicates the thickness of the organic film while
"E" indicates Young's modulus of the organic film.
Inventors: |
Kondo; Koichi; (Miyagi,
JP) ; Ono; Hiroshi; (Miyagi, JP) ; Numata;
Yukihiro; (Miyagi, JP) |
Family ID: |
42016867 |
Appl. No.: |
13/128759 |
Filed: |
July 29, 2009 |
PCT Filed: |
July 29, 2009 |
PCT NO: |
PCT/JP2009/003591 |
371 Date: |
May 11, 2011 |
Current U.S.
Class: |
428/216 ;
427/131; 428/457 |
Current CPC
Class: |
Y10T 428/31678 20150401;
H01F 41/14 20130101; H01F 10/265 20130101; Y10T 428/24975 20150115;
H01F 41/24 20130101; H05K 9/0075 20130101; C23C 18/00 20130101;
H01F 10/20 20130101 |
Class at
Publication: |
428/216 ;
428/457; 427/131 |
International
Class: |
B32B 7/02 20060101
B32B007/02; B32B 15/04 20060101 B32B015/04; B05D 5/00 20060101
B05D005/00; B05D 1/36 20060101 B05D001/36 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2008 |
JP |
2008-289493 |
Claims
1. A fabrication method of a magnetic film provided body
comprising: preparing a base body and forming a magnetic film on
the base body, the magnetic film comprising at least one organic
film and at least one ferrite film alternately layered, wherein the
formation of the magnetic film alternately out comprises: forming a
ferrite film through a ferrite plating method, the ferrite film
having a thickness of 20 .mu.m or less; and forming an organic
film, the organic film having a thickness of 0.1 .mu.m to 20 .mu.m,
both inclusive, the organic film having a ratio t/E of 0.025
.mu.m/GPa or more, where "t" indicates the thickness of the organic
film, and "E" indicates Young's modulus of the organic film.
2. The fabrication method as recited in claim 1, wherein the
formation of the magnetic film includes forming one layer of the
organic film on the base body.
3. The fabrication method as recited in claim 1, wherein the
formation of the magnetic film includes forming one layer of the
ferrite film on the base body.
4. A magnetic film provided body comprising: a base body; and a
magnetic film provided on the base body, wherein: the magnetic film
comprises at least one organic film and at least one ferrite film
alternately layered; and an adhesive strength between the organic
film and the ferrite film is 0.1 kN/m or more.
5. The magnetic film provided body as recited in claim 4, wherein:
the organic film of the magnetic film is provided directly on the
base body; and an adhesive strength between the organic film and
the base body is 0.1 kN/m or more.
6. The magnetic film provided body as recited in claim 4, wherein:
the base body is made of organic material; the ferrite film of the
magnetic film is provided directly on the base body; and an
adhesive strength between the ferrite film and the base body is 0.1
kN/m or more.
7. The magnetic film provided body as recited in claim 4, wherein:
each ferrite film has a thickness of 20 .mu.m; each organic film
has a thickness of 0.1 .mu.m to 2.0 .mu.m, both inclusive; and the
organic film has a ratio t/E of 0.025 .mu.m/GPa or more, where "t"
indicates the thickness organic film, and "E" indicates Young's
modulus of the organic film.
8. The magnetic film provided body as recited in claim 7, wherein a
total thickness of the at least one ferrite film included in the
magnetic film is 1 .mu.m or more.
9. The magnetic film provided body as recited in claim 4, wherein
the ferrite film(s) is one formed through a ferrite plating method.
Description
TECHNICAL FIELD
[0001] This invention relates to a magnetic film provided body and
a fabrication method thereof, wherein the magnetic film provided
body is formed of a base body provided with a magnetic film,
especially, a spinel-structured ferrite film.
BACKGROUND ART
[0002] A ferrite plating method provides a fine quality ferrite
film and is, for example, disclosed in Patent Document 1. The
ferrite plating method comprises the steps of: preparing a specific
solution containing at least ferrous ions; bringing a surface of a
base body into contact with the specific solution to cause
Fe.sup.2+ ions, or Fe.sup.2+ ions and other metal hydroxide ions,
to be absorbed on the surface of the base body; and oxidizing the
absorbed Fe.sup.2+ ions to obtain Fe.sup.3+ ions to cause the
Fe.sup.3+ ions and metal hydroxide ions in the specific solution to
undergo a ferrite crystallization reaction so that a ferrite film
is formed on the surface of the base body.
[0003] The above-described ferrite plating method allows use of any
kinds of base bodies, provided that the base bodies have tolerance
to the solution. The ferrite plating method can produce a
spinel-structured ferrite film under a relatively low temperature
(the normal temperature to the boiling point of the solution or
lower) because it is based on the reaction by using the solution.
The ferrite plating method is superior to other ferrite film
formation techniques in fewer limitations for the base body. The
ferrite film formed through the ferrite plating method is superior
in that the ferrite film, which is of ceramics, has flexibility and
is easy to handle.
[0004] There are provided Patent Document 2 to Patent Document 6
and Non-Patent Document 1 as documents concerning the ferrite
plating method. Patent Document 2 discloses a technique which
homogenizes ferrite films formed and increases reaction rate in a
ferrite film formation process. Patent Document 3 discloses a
technique which makes a surface of a base body denatured and active
by plasma processing so that ferrite films can be formed on the
various base bodies. Patent Document 4 discloses a technique which
relates to increasing ferrite film formation rate. Patent Document
5 discloses a technique which improves an insulation property of a
ferrite film or a support body by coating the ferrite film or the
support body with an insulation material. Patent Document 6
discloses a technique which relates to a ferrite thin film having
high magnetic permeability over a wide frequency range. Patent
Document 7 discloses a technique of forming a magnetic film (a
ferrite film) by laminating strain-relaxation chemical compound
layers and ferrite-constituent atom layers. Non-Patent Document 1
discloses a technique which relates to a noise-suppressor using the
ferrite thin film based on the technique of Patent Document 6.
[0005] Patent Document 1: JPA S59-111929 [0006] Patent Document 2:
JPA S60-140713 [0007] Patent Document 3: JPA S61-030674 [0008]
Patent Document 4: JPA H02-166311 [0009] Patent Document 5: JPA
2005-298875 [0010] Patent Document 6: JPA 2005-191098 [0011] Patent
Document 7: JPA H1-122929
[0012] Non-Patent Document 1: "GHz Conducted Noise Suppression
Effects by Ferrite Thin Films Plated onto Polyimide Sheet", NEC
TOKIN Technical Review vol. 31, p. 92, 2004; Koichi Kondo, Tatsuya
Chiba, Hiroshi Ono, Shigeyoshi Yoshida and Masanori Abe
DISCLOSURE OF INVENTION
Problems to be Solved by Invention
[0013] According to Patent Document 7, an exfoliation would not
occur even when a thickness of the magnetic film is more than two
micro meters. However, depending on the forming conditions, the
magnetic film would be exfoliated from a base body or the magnetic
film itself would be damaged in a case where the thickness is more
than two micro meters
[0014] It is therefore an object of the present invention to
determine an optimum forming condition of providing a magnetic film
on a base body and to provide a fabrication method of a magnetic
film provided body in which no exfoliation occurs even when a
thickness of the magnetic film is more than two micro meters.
[0015] In addition, it is another object of the present invention
to provide a magnetic film provided body which is fabricated in
accordance with the above-mentioned fabrication method thereof.
Means for Solving the Problems
[0016] One aspect of the present invention provides a fabrication
method of a magnetic film provided body comprising preparing a base
body and forming a magnetic film on the base body. The magnetic
film comprises organic film(s) and ferrite film(s) alternately
layered. The formation of the magnetic film alternately carries
out: forming a ferrite film through a ferrite plating method, the
ferrite film having a thickness of 20 .mu.m or less; and forming an
organic film, the organic film having a thickness of 0.1 .mu.m to
20 .mu.m, both inclusive. The organic film has a ratio t/E of 0.025
.mu.m/GPa or more, where "t" indicates the thickness of the organic
film, and "E" indicates Young's modulus of the organic film.
[0017] Another aspect of the present invention provides a magnetic
film provided body comprising a base body and a magnetic film
provided on the base body. The magnetic film comprises organic
film(s) and ferrite film(s) alternately layered and an adhesive
strength between the organic film and the ferrite film is 0.1 kN/m
or more.
Advantageous Effect of Invention
[0018] According to the present invention, by determining an
optimum condition, a magnetic film which has a high adhesive
strength can be formed on a base body, wherein the magnetic film
comprises an organic film(s) and a ferrite film(s).
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 is a cross-sectional view schematically showing a
magnetic film provided body according to an embodiment of the
present invention.
[0020] FIG. 2 is a view schematically showing a film formation
apparatus which is used in a fabrication method of the magnetic
provided body according to an embodiment of the present
invention.
[0021] FIG. 3 is a cross-sectional view schematically showing a
variation example of the magnetic film provided body of FIG. 1.
[0022] FIG. 4 is a view schematically showing an examination method
of adhesive strength.
[0023] FIG. 5 is a view schematically showing an examination method
of flexibility.
DESCRIPTION OF NUMERALS
[0024] 1 Reaction Solution Nozzle [0025] 2 Oxidizing Solution
Nozzle [0026] 3 Base body [0027] 4 Turn Table [0028] 5, 5a Magnetic
Film [0029] 6 Organic Film [0030] 7 Ferrite Film [0031] 10, 10a
Magnetic Film Provided Body [0032] 20 Stage [0033] 22 Double-sided
Tape [0034] 24 PET Film [0035] 30 Mount Plate [0036] 32 Vibration
Plate [0037] R Bending Radius
BEST MODE FOR CARRYING OUT INVENTION
[0038] As shown in FIG. 1, a magnetic film provided body 10
according to an embodiment of the present invention comprises a
base body 3 and a magnetic film 5 provided on the base body 3. The
magnetic film 3 comprises organic films 6 and ferrite films 7
alternately layered. An adhesive strength between the organic film
6 and the ferrite film 7 is 0.1 kN/m or more. Especially, in the
magnetic film provided body 10 of the present embodiment, it is not
the ferrite film 7 but the organic film 6 which is formed directly
on the base body 3. An adhesive strength between the
directly-formed organic film 6 and the base body 3 is 0.1 kN/m or
more, too. In the present embodiment, the adhesive strength between
the base body 3 and the organic film 6 as well as each adhesive
strength between the organic film 6 and the ferrite film 7 is 0.1
kN/m or more so that an exfoliation problem may not occur. The
adhesive strength in the embodiment is examined by the exfoliation
test in conformance with JIS C5016 (test methods for flexible
printed wiring boards).
[0039] In order that the adhesive strength between the layers to be
0.1 kN/m or more, in the embodiment, optimum conditions of a
thickness of the ferrite film, a thickness of the organic film, and
a ratio t/E are defined as follows, where "t" indicates the
thickness of the organic film 6, and "E" indicates Young's modulus
of the organic film 6. First, the ratio of t/E of each organic film
6 is defined to be 0.025 .mu.m/GPa or more. By the use of the
organic film 6 which satisfies the condition, a sufficient stress
relaxation effect can be obtained. In addition, the thickness of
each ferrite film 7 is defined to be 20 .mu.m or less, and the
organic film 6 which has a thickness of 0.1 .mu.m or more is
interposed between the ferrite films 7. Therefore, the
above-mentioned adhesive strength of 0.1 kN/m or more can be
obtained. In consideration of productivity, the ratio of t/E is
preferred to be 1000 .mu.m/GPa or less. A total thickness of the
ferrite films 7 included in the magnetic film 5 is defined to be 1
.mu.m or more so that the magnetic film 5 which produces a high
electromagnetic effect can be obtained. The thickness of each
organic film 6 is defined to be 20 .mu.m or less so that a device
which uses the magnetic film provided body of the embodiment can be
miniaturized.
[0040] There is no limitation for a material of the base body 3,
provided that the material has tolerance to the solution. For
example, the material of the base body 3 may be selected from a
group consisting of: various kinds of plastics such as polyimide
sheet, polyethylene terephthalate and so on; various kinds of
metals such as copper, nickel, silver, gold, tungsten, molybdenum,
platinum, palladium, iron, iron alloy and so on; various kinds of
organic layered sheets, in other words, various kinds of layered
sheets such as paper epoxy, glass epoxy, grass polyester and so on;
various kinds of glass; ceramics; and so on.
[0041] In the embodiment, a purpose of using the organic film 6 is
not to insulate between the ferrite films 7 nor between the ferrite
film 7 and an external member. As for a material of the organic
film 6, a material having any specific electrical resistance may be
used. For example, the organic film 6 may be made of resin selected
from a group consisting of phenol resin, epoxy resin, melamine
resin, urea resin, unsaturated polyester resin, polyimide,
polyethylene, polypropylene, polyvinyl chloride, polyvinylidene
chloride, polystyrene, polyvinyl acetate, ABS resin, acrylic resin,
polyamide, nylon, polyacetal, polycarbonate, polybutylene
terephthalate, polyethylene terephthalate, polyphenylene sulfide,
polysulfone, polyethersulfone, polyarylate, polymer liquid crystal,
polyamide-imide and one of these resin including metal powder. The
organic film 6 may be made of resin which includes magnetic powder.
For example, a material of the magnetic powder may be selected from
a group consisting of ferrite, Fe, Fe--Co alloy, Fe--Si alloy, Fe
system alloy such as Fe--Si--Al, Ni system alloy such as Ni--Fe
alloy and so on. Furthermore, the organic film 6 may be a high
dielectric constant material made of resin which includes carbon or
metal powder.
[0042] In the embodiment, there is no limitation to a film
formation method of the organic film 6. For example, the organic
film 6 may be formed by applying a resin which has moderate
fluidity by an applying apparatus such as a spin coater, or the
organic film 6 may be formed by a film formation apparatus such as
sputtering and so on.
[0043] In the embodiment, the ferrite film(s) 7 is formed through
the ferrite plating method. A film formation apparatus, for example
as shown in FIG. 2, may be used for forming a ferrite plate. The
illustrated film formation apparatus is an apparatus for forming a
ferrite film on the base body 3 and comprises a reaction solution
nozzle 1, an oxidizing solution nozzle 2 and a turn table 4. The
turn table 4 is a table turnable around its axis. The base body 3
moves in response to the turning of the turn table 4. The reaction
solution nozzle 1 is configured to supply a reaction solution for
the turn table 4, wherein the reaction solution contains at least
ferrous ions (Fe.sup.2+ ions). The reaction solution nozzle 1 is
fixed above the turn table 4. The oxidizing solution nozzle 2 is
configured to supply an oxidizing solution for the turn table 4,
wherein the oxidizing solution contains at least an oxidizing
agent. The oxidizing solution nozzle 2 is fixed above the turn
table 4. In the illustrated film formation apparatus, the reaction
solution nozzle 1 is positioned above one of half regions of the
turn table 4 stopped, while the oxidizing solution nozzle 2 is
positioned above the other half region of the turn table 4 stopped.
When the turn table 4 is turned with the reaction solution and the
oxidizing solution respectively supplied from the reaction solution
nozzle 1 and the oxidizing solution nozzle 2, the reaction solution
and the oxidizing solution are alternately supplied for the base
body 3, and excess reaction solution and oxidizing solution are
removed by centrifugal force. As a result, the ferrite film based
on the ferrite plating method is formed on the base body 3.
Compositions of the ferrite films 7 may be different from each
other.
[0044] In the embodiment, it is not the ferrite film 7 which is
formed directly on the base body 3. However, for example, a
magnetic film provided body 10a may comprise a magnetic film 5a
formed by forming the ferrite film 7 directly on the base body 3,
as shown in FIG. 3. In this case, the base body 3 may be made of an
organic material. Similarly to the organic film 6, the organic
material in this case is preferred to have a ratio t/E of 0.025
.mu.m/GPa or more. In this manner, the adhesive strength between
the base body 3 made of the organic material and the organic film 7
directly formed thereon can be 0.1 kN/m or more. Furthermore, it is
preferable to maintain a ratio of t/E of the organic material of
the base body 3 to be 1000 .mu./GPa or less.
[0045] For a property examination of the magnetic film provided
body, various magnetic film provided bodies were formed, as listed
in the following table. In the table, each of concrete examples
1.about.5 is a magnetic film provided body which satisfies a
condition according to the present embodiment, while each of
comparative examples 1.about.5 is a magnetic film provided body
which does not satisfy the condition according to the present
embodiment.
TABLE-US-00001 TABLE 1 Concrete Concrete Concrete Concrete Concrete
Example 1 Example 2 Example 3 Example 4 Example 5 Material and
Ferrite 2 Ferrite 1 Thickness(.mu.m) of 6th Layer Material and
Polyimide 1 Polyimide 0.1 Thickness(.mu.m) B A of 5th Layer
Material and Ferrite 2 Ferrite 1 Ferrite 0.5 Thickness(.mu.m) of
4th Layer Material and Polyimide 1 Polyimide 0 1 Polyimide 20
Ferrite 3 Ferrite 3 Thickness(.mu.m) B A B of 3rd Layer Material
and Ferrite 2 Ferrite 1 Ferrite 0.5 Polyimide 6 Epoxy + Fe 20
Thickness(.mu.m) of 2nd Layer Material and Polyimide 1 Polyimide
0.1 Polyimide 20 Ferrite 3 Ferrite 3 Thickness(.mu.m) B A B of 1st
Layer Material and Glass 1000 Glass 1000 Glass 1000 Polyimide 25
Polyimide 25 Thickness(.mu.m) of Base Body Total Thickness 6 3 1 6
6 (.mu.m) of the Ferrite Film Position of the between PET between
PET between PET between PET between PET Existence and and and and
and of Exfoliation Double-sided Double-sided Double-sided
Double-sided Double-sided tape tape tape tape tape Adhesive >2.0
>2.0 >2.0 >2.0 >2.0 Strength between the Layers (kN/m)
Young's Modulus 3 4 3 4 4 E GPa) of the Organic Film Film Thickness
1 0.1 20 6 20 t(.mu.m) of the Organic Film t/E (pm/GPa) 0.33 0.025
6.67 1.5 5 Occurrence of the -- -- -- No No Exfoliation after
Exfoliation Exfoliation Bending Test (100,000 tirnes) Comparative
Comparative Comparative Comparative Example 1 Example 2 Example 3
Example 4 Material and Thickness(.mu.m) of 6th Layer Material and
Thickness(.mu.m) of 5th Layer Material and Thickness(.mu.m) of 4th
Layer Material and Thickness(.mu.m) of 3rd Layer Material and
Ferrite 25 Ferrite 18 Thickness(.mu.m) of 2nd Layer Material and
Polyimide 2 Ferrite 5 Polyimide 0.05 Ferrite 6 Thickness(.mu.m) A A
of 1st Layer Material and Glass 1000 Glass 1000 Glass 1000
Polyimide 25 Thickness(.mu.m) of Base Body Total Thickness 25 5 18
6 (.mu.m) of the Ferrite Film Position of the between 1st between
between between Existence layer and Base Body Base Body Base Body
of Exfoliation 2nd layer and and and 1st layer 1st layer lst layer
Adhesive 0.05 Exfoliation 0.09 1 Strength between Occurs the Layers
before the (kN/m) Test Young's Modulus 4 -- 4 -- E GPa) of the
Organic Film Film Thickness 2 -- 0.05 -- t(.mu.m) of the Organic
Film t/E (pm/GPa) 0.5 -- 0.01 -- Occurrence of the -- -- --
Exfoliation Exfoliation after Occurs Bending Test (100,000
tirnes)
[0046] Hereinafter, a supplemental explanation will be made about a
size and a fabrication condition of each of the examples listed in
the table.
[0047] A size of the base body 3 made of the glass substrate is 50
mm.times.50 mm.times.1 mm. A size of the base body 3 made of the
polyimide sheet is 50 mm.times.50 mm.times.25 mm. The former
corresponds to the concrete example 1.about.3 and the comparative
example 1.about.3. The latter corresponds to the concrete example 4
and 5 and the comparative example 4.
[0048] In the above-mentioned examples of the organic films 6,
"Polyimide A" is a polyimide film which has relatively high Young's
modulus (Young's modulus of 4 GPa), and "Polyimide B" is a
polyimide film which has relatively low Young's modulus (Young's
modulus of 3 GPa). An explanation will be made for a forming method
of the polyimide film with taking an example where the polyimide
film is formed on a glass substrate. First, a dilute agent was
added into and mixed with polyamic acid of a precursor of
polyimide. Secondly, the aforementioned mixture was applied on a
surface of the glass substrate by a spin coater. An application
thickness was adjusted by viscosity of a solution, the number of
revolutions of the spin coater, and so on. After that, the glass
substrate applied with the solution was heated at 90.degree. C. for
5 minutes, followed by heated at 320.degree. C. for 60 minutes.
Thus, the polyimide film was formed on the glass substrate. By
adjusting the formation conditions, the organic films 6 can be
obtained wherein the organic films 6 is made of the polyimide A of
high Young's modulus (4 GPa) or the polyimide B of low Young's
modulus (4 GPa).
[0049] The organic film 6 of the concrete example 5 is a mixture of
epoxy resin and Fe. As for the organic film 6, Fe particle was
mixed into pre-polymer of epoxy resin, wherein Fe particle has an
average particle diameter of 3 .mu.m and the Fe content was 45 vol
%, and thereafter a curing agent was mixed. Next, the mixture was
applied so that an average thickness is 2 .mu.m. Furthermore, the
applied film was maintained at 100.degree. C. for 6 hours and
cured. A specific resistance of the mixture of epoxy resin and Fe
formed in the above-described manner was 100 .OMEGA.cm.
[0050] The ferrite film 7 was formed as follows. As a
pre-treatment, a turn table 4 was turned after the base body 3 was
disposed on the turn table 4, while deoxidized ion-exchange water
was provided on the base body 3 under a heat treatment up to
90.degree. C. Next, nitrogen gas was introduced into the film
formation apparatus so that deoxide atmosphere was prepared in the
apparatus. Then, the step of supplying the reaction solution for
the base body 3 from the reaction solution nozzle 1 and the step of
supplying the oxidizing solution for the base body 3 from the
oxidizing solution nozzle 2 were carried out while the turn table 4
was turned. In other words, the step of supplying the reaction
solution and the step of supplying the oxidizing solution were
carried out alternately and repeatedly. Here, flow rate upon the
supply of each of the reaction solution and the oxidizing solution
was set to 40 ml/min. The reaction solution was prepared by
dissolving FeCl.sub.2-4H.sub.2O, NiCl.sub.2-6H.sub.2O and
ZnCl.sub.2 into deoxidized ion-exchange water. The oxidizing
solution was prepared by dissolving NaNO.sub.2 and
CH.sub.3COONH.sub.4 into deoxidized ion-exchange water. The
reaction solution and the oxidizing solution may be formed with
reference to, for example, US2009-0047507A1, US2007-0231614A1, or
other materials. Here, the explanation was made with taking an
example where the ferrite film 7 was formed on the base body 3.
Similar method was carried out for a case where the ferrite film 7
was formed on the organic film 6.
[0051] Chemical composition of each ferrite film of the concrete
example 1.about.5 and the comparative example 1.about.4 as listed
on the table was examined by an inductively coupled plasma
spectroscopy (ICPS) method. As a result, each of the ferrite films
has an average composition of
Ni.sub.0.2Zn.sub.0.3Fe.sub.2.5O.sub.4. A scanning electron
microscope (SEM) was used for a configuration analysis such as
measurement of film thickness.
[0052] An examination of the adhesive strengths was carried out in
conformance with JIS C5016 (test methods for flexible printed
wiring boards). Peel strength was taken as the adhesive strength.
In detail, as shown in FIG. 4, the obtained magnetic film provided
body 10 was fixed on a stage 20 with a double-sided tape 22. A PET
film 24 was stuck to the top layer of the ferrite film 7 by a
double sided tape 22. In this state, the PET film was peeled off in
the 90.degree. direction. By recording a position of exfoliation
occurred between the layers and the scale on a force gages at that
time, the value of the scale was taken as the adhesive
strength.
[0053] An examination of the flexibility was carried out in
conformance with JIS C5016 (a test method for flexible printed
wiring boards). In detail, as shown in FIG. 5, the obtained
magnetic film provided body 10 was bent, where the bending radius R
was 3 mm. End portions of the magnetic film provided body 10 was
fixed to a mount plate 30 and a vibration plate 32, respectively.
In this state, a bending test was carried out for the vibration
plate 32 which was subjected to the reciprocating motion for a
hundred-thousand times, where each stroke is 30 mm and each
reciprocate cycle is twice per second. After the bending test of
the reciprocating motion for 100 thousand times, a visual
examination was carried out to check the occurrence of the
exfoliation between any layers. When there was no exfoliation as a
result of the examination, flexibility was judged to be fine. The
bending test was carried out only for the magnetic film provided
body of which the base body is polyimide, as the glass substrate
cannot be bent. The results of the examinations are also listed on
the aforementioned tables.
[0054] It is obvious from the tables that for the magnetic film
provided bodies of the concrete examples 1.about.5, each adhesive
strength between the organic film 6 and the ferrite film 7 is 0.1
kN/m or more because each organic film 6 has a thickness of 0.1
.mu.m to 20 .mu.m, both inclusive; each ferrite film(s) 7 has a
thickness of 20 .mu.m or less; and a ratio t/E is of 0.025
.mu.m/GPa or more, where "t" indicates the thickness of the organic
film, and "E" indicates Young's modulus of the organic film.
Accordingly, no exfoliation occurs in the magnetic film provided
body 10.
[0055] On the other hand, for the magnetic film provided bodies of
comparative examples 1.about.3, each adhesive strength in the
magnetic film provided bodies are 0.1 kN/m or less because the
condition such as thickness of the organic films, Young's modulus
and thickness of the ferrite are not satisfied. This results in
occurrence of the exfoliation between any layers of the magnetic
film provided body 10. In the comparative example 4, exfoliation
occurred after the 100 thousand times of the bending test. This is
caused by the single layered ferrite film 7 formed on the base body
3 made of the organic material.
INDUSTRIAL APPLICABILITY
[0056] A ferrite provided body according to the present invention
can be used in an inductance element, an impedance element, a
magnetic head, a microwave element, a magnetostriction element and
a high-frequency magnetic device such as an electromagnetic
interference suppressor. Especially, it is suitable in the case
where the magnetic film including the ferrite film is required to
be relatively thick. The electromagnetic interference suppressor is
for suppressing electromagnetic problems caused by interferences of
undesired electromagnetic waves in a high frequency region.
* * * * *