U.S. patent application number 10/685417 was filed with the patent office on 2004-04-29 for article with electronic circuit formed and method of manufacturing the same.
Invention is credited to Akiguchi, Takashi, Maruyama, Yoshio, Miyakawa, Hidenori, Mori, Kazuhiro, Nakata, Mikiya, Wada, Yoshinori, Yamauchi, Hiroshi.
Application Number | 20040078965 10/685417 |
Document ID | / |
Family ID | 18606110 |
Filed Date | 2004-04-29 |
United States Patent
Application |
20040078965 |
Kind Code |
A1 |
Miyakawa, Hidenori ; et
al. |
April 29, 2004 |
Article with electronic circuit formed and method of manufacturing
the same
Abstract
A package is formed by covering a circuit board with a
thermoplastics film. The cylindrical or sheet-like thermoplastic
film is decompressed and used to cover the circuit board to protect
the board and components mounted on the board.
Inventors: |
Miyakawa, Hidenori;
(Moriguchi-shi, JP) ; Maruyama, Yoshio;
(Kyoto-shi, JP) ; Yamauchi, Hiroshi; (Katano-shi,
JP) ; Nakata, Mikiya; (Suita-shi, JP) ;
Akiguchi, Takashi; (Osaka-shi, JP) ; Wada,
Yoshinori; (Suita-shi, JP) ; Mori, Kazuhiro;
(Katano-shi, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
18606110 |
Appl. No.: |
10/685417 |
Filed: |
October 16, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10685417 |
Oct 16, 2003 |
|
|
|
09818899 |
Mar 28, 2001 |
|
|
|
Current U.S.
Class: |
29/840 ; 174/260;
29/830; 29/832; 29/841 |
Current CPC
Class: |
H05K 3/284 20130101;
Y10T 29/49131 20150115; Y10T 29/4913 20150115; Y10T 29/49144
20150115; Y10T 29/49146 20150115; Y10T 29/49126 20150115; H05K
5/068 20130101 |
Class at
Publication: |
029/840 ;
174/260; 029/832; 029/830; 029/841 |
International
Class: |
H05K 001/16; H05K
003/36 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2000 |
JP |
2000-90509 |
Claims
What is claimed is:
1. An electronic circuit-formed article manufacturing method of
manufacturing an article with an electronic circuit formed, by
comprising covering an area, which has electronic components on an
article with an electronic circuit formed having the electronic
components, with sheet-like films.
2. An electronic circuit-formed article manufacturing method of
manufacturing an article with an electronic circuit formed, by
comprising covering both a front and a back surfaces of a circuit
board having electronic components with two sheet-like films, and
packaging the circuit board with the sheet-like films.
3. A method of manufacturing an article with an electronic circuit
formed as defined in claim 2, wherein the front surface of the
circuit board is covered with one sheet-like film out of the two
sheet-like films, and then the back surface of the circuit board is
covered with the other sheet-like film to package the circuit
board.
4. A method of manufacturing an article with an electronic circuit
formed as defined in claim 2, wherein the circuit board is packaged
by simultaneously covering both the front and the back surfaces of
the circuit board with the two sheet-like films.
5. A method of manufacturing an article with an electronic circuit
formed, comprising: printing or applying an electronic component
mounting bonding agent on electrodes of a circuit board; bringing
electronic components close to above positions through mechanical
application of pressure; fixing the components on the board through
heating; and packaging the board with the cylindrical film or
sheet-like films.
6. A method of manufacturing an article with an electronic circuit
formed as defined in claim 5, wherein the electronic component
mounting bonding agent is a metallic solder or a thermosetting
conductive adhesive.
7. An article with an electronic circuit formed, manufactured by
the method of manufacturing an article with an electronic circuit
formed as defined in claim 5.
Description
[0001] This application is a Divisional Application of Ser. No.
09/818,899 filed Mar. 28, 2001, now allowed.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method of manufacturing
an article with an electronic circuit which is composed of a
circuit unit, such as a circuit board with electronic components
mounted thereon, covered with a cylindrical or a sheet-like film.
The invention also relates to an article with an electronic circuit
manufactured by the method of manufacturing the same.
[0003] In recent years, as a method of forming circuit boards,
there has been known a reflow process using a solder paste or a
conductive adhesive as a bonding agent.
[0004] However, the solder paste contains zinc, which is not
desirable in terms of conservation of the global environment.
[0005] The conductive adhesive contains a large amount of metallic
powder filled into resin, which causes poor bond strength and low
impact resistance compared to a metallic solder. To improve impact
resistance, there is a separately-conducted method in which
components are sealed on a board using a sealant. This method,
however, brings about difficulty in later board repair, including
replacement of components, and causes difficulty in recovery and
recycle of the components. In addition, there are other issues,
such as hardening of sealing resin that takes a long time.
[0006] In the case where the board is sealed with silicon resin or
urethane resin for the purpose of protecting the board from
moisture or dust, there arises difficulty, like in the above case,
in later board repair including replacement of components, as well
as difficulty in recovery and recycle of the components. In
addition, there are other issues, such as hardening of sealing
resin that takes a long time.
[0007] Japanese Laid-Open Patent Publication No. 8-18275 proposes a
technology as a solution for these issues. According to this
publication, a board is inserted into a rectangle bag which has a
conductive layer and a thermal weld layer and whose three sides are
closed. After the board is inserted through the remaining one open
side of the bag, the open side is closed through heat shielding and
thermal deposition for achieving electromagnetic shielding of the
board.
[0008] With the above-disclosed structure, three sides of a film
"bag" are closed in advance before the board is inserted therein,
which limits the size of a board to be inserted into the bag.
Accordingly, use of different sized boards requires steps of
preparing different sized bags and selecting an appropriate sized
bag corresponding to a board in use, making the technology complex
and less general.
[0009] In order to solve the above-stated issues, the object of the
present invention is to provide an article with an electronic
circuit, as well as to provide a method of manufacturing the same.
Each of the methods is capable of corresponding to different sized
boards and is rich in generality, allows packaging for a short
period of time, provides an increase in impact resistance, and
facilitates recovery and recycle of components, boards, and the
like.
SUMMARY OF THE INVENTION
[0010] In order to accomplish the above object, the present
invention has the following embodiments.
[0011] According to a first aspect of the present invention, there
is provided an electronic circuit-formed article manufacturing
method characterized by manufacturing an article with an electronic
circuit. A circuit board having electronic components is inserted
into a cylindrical film so that the board is covered with the
cylindrical film. Thereafter, both opening portions of the
cylindrical film are sealed to package the circuit board.
[0012] According to a second aspect of the present invention, there
is provided an electronic circuit-formed article manufacturing
method including covering an area, which has electronic components
on an article with an electronic circuit formed having the
electronic components, with sheet-like films.
[0013] According to a third aspect of the present invention, there
is provided an electronic circuit-formed article manufacturing
method including covering both front and back surfaces of a circuit
board having electronic components with two sheet-like films, and
packaging the circuit board with the sheet-like films.
[0014] According to a fourth aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in the third aspect, wherein the front surface
of the circuit board is covered with one of the two sheet-like
films. The back surface of the circuit board is then covered with
the other sheet-like film to package the circuit board.
[0015] According to a fifth aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in the third aspect, wherein the circuit board
is packaged by simultaneously covering both the front and the back
surfaces of the circuit board with the two sheet-like films.
[0016] According to a sixth aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to fifth aspects,
wherein the film is heated in advance to be softened, and then the
board is covered.
[0017] According to a seventh aspect of the present invention,
there is provided a method of manufacturing an article with an
electronic circuit as defined in any one of the first to sixth
aspects, wherein the thickness of the film is 10 to 200 .mu.m.
[0018] According to an eighth aspect of the present invention,
there is provided a method of manufacturing an article with an
electronic circuit as defined in any one of the first to seventh
aspects, wherein during the process of covering the board with the
film, decompression is conducted between the film and the board so
as to make the film follow the components or the board.
[0019] According to a ninth aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to eighth aspects,
wherein the film is composed of a heat-shrinkable material. The
film is heated and heat-shrunken so as to make the film follow the
board and the components.
[0020] According to a 10th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to ninth aspects,
wherein the film is composed of a visible material.
[0021] According to an 11th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to 10th aspects, wherein
during covering of the board with the film, decompression is
conducted between the film and the board through use of a hole of
the component so as to make the film follow the components or the
board. A valve provided in the hole then prevents gas from entering
between the film and the board from outside through the air
hole.
[0022] According to a 12th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to 11th aspects, wherein
an elastic sheet is provided between the film and the components or
the board.
[0023] According to a 13th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to 12th aspects, wherein
an adhesion layer is provided in an internal surface of the film
for adhering the film to the electronic components or the
board.
[0024] According to a 14th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to 13th aspects, wherein
the film allows gas generated from flame retarders or solder flux
used in the board and the components as well as moisture generated
from the board made of paper phenol to pass from inside to outside
but to prevent moisture and dust from invading the inside of the
film from the outside.
[0025] According to a 15th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to 14th aspects, wherein
an absorbent material such as desiccants and activated carbon is
provided inside the film for absorbing gas generated from flame
retarders or solder flux used in the board and the components as
well as moisture generated from the board made of paper phenol.
[0026] According to a 16th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to 15th aspects, wherein
the board is heated in advance to a temperature equal to or higher
than a temperature at which the film is softened, and to a
temperature lower than a temperature at which the film is melted,
and to a temperature in a range so that a bonding agent to bond the
board and the components is not melted. Then, the board is packaged
with the film, so that the film is softened upon contact with the
heated board, making the film follow the board.
[0027] According to a 17th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in any one of the first to eighth aspects and
10th to 16th aspects, wherein the film is composed of a
thermoplastic material. When the board is covered with the film,
decompression is executed between the film and the board so as to
make the film follow the components or the board, while at the same
time, the film is heated and attached to each other to achieve
sealing.
[0028] According to an 18th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit including inserting a circuit board having electronic
components into a cylindrical film. Both opening portions of the
cylindrical film are then sealed, and the cylindrical film is cut
to package the circuit board.
[0029] According to a 19th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit, including printing or applying an electronic component
mounting bonding agent on electrodes of a circuit board, and
bringing electronic components close to above positions through
mechanical application of pressure. The components are then fixed
on the board through heating, and the board is packaged with
cylindrical film or sheet-like films.
[0030] According to a 20th aspect of the present invention, there
is provided a method of manufacturing an article with an electronic
circuit as defined in the 19th aspect, wherein the electronic
component mounting bonding agent is a metallic solder or a
thermosetting conductive adhesive.
[0031] According to a 21st aspect of the present invention, there
is provided an article with an electronic circuit, manufactured by
the method of manufacturing an article with an electronic circuit
formed as defined in any one of the first to 20th aspects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] These and other aspects and features of the present
invention will become clear from the following description of the
preferred embodiments with reference to the accompanying drawings,
in which:
[0033] FIG. 1 is a side view showing a mount board with components
mounted thereon to which a method of manufacturing an article with
an electronic circuit according to a first embodiment of the
present invention is applied;
[0034] FIG. 2 is a perspective view showing a mount board with
components mounted thereon to which the method of manufacturing an
article with an electronic circuit according to the first
embodiment of the present invention is applied;
[0035] FIG. 3 is a perspective view showing a cylindrical film for
use in the method of manufacturing an article with an electronic
circuit according to the first embodiment of the present
invention;
[0036] FIGS. 4A and 4B are side views each showing an article with
an electronic circuit before and after being formed by the method
of manufacturing an article with an electronic circuit according to
the first embodiment of the present invention;
[0037] FIG. 5 is an explanatory view explaining the state of
softening a film in a method of manufacturing an article with an
electronic circuit according to a second embodiment of the present
invention;
[0038] FIG. 6 is an explanatory view showing a schematic
configuration of a vacuum forming unit for use in a method of
manufacturing an article with an electronic circuit according to a
third embodiment of the present invention;
[0039] FIG. 7 is an explanatory view showing the state of
conducting vacuum forming with the use of the vacuum forming unit
of FIG. 6;
[0040] FIG. 8 is a perspective view showing an article with an
electronic circuit formed obtained through vacuum packaging of a
mount board with components mounted thereon in the method of
manufacturing an article with an electronic circuit according to
the third embodiment of the present invention;
[0041] FIGS. 9A and 9B are, respectively, a cross sectional view
showing an article with an electronic circuit obtained through
vacuum packaging of a mount board with components mounted thereon,
and a partially enlarged cross sectional view showing a part of
FIG. 9A indicated with an arrow A, in the method of manufacturing
an article with an electronic circuit formed according to the third
embodiment of the present invention;
[0042] FIG. 10 is an explanatory view showing the state of
packaging a mount board with components mounted thereon with a film
disposed on and under the mount board in a method of manufacturing
an article with an electronic circuit according to a fourth
embodiment of the present invention;
[0043] FIG. 11 is a schematic perspective view showing a device for
use in the method of manufacturing an article with an electronic
circuit according to the fourth embodiment of the present
invention;
[0044] FIG. 12 is an explanatory view showing the state of vacuum
sucking from a connector of a mount board with components mounted
thereon in a method of manufacturing an article with an electronic
circuit according to a fifth embodiment of the present
invention;
[0045] FIG. 13 is an explanatory view showing a state in which
vacuum-sucking has been performed from the connector of the mount
board with the components mounted thereon in the method of
manufacturing an article with an electronic circuit formed
according to the fifth embodiment;
[0046] FIG. 14 is an explanatory view showing a state of packaging
a mount board with components mounted thereon with the use of a
spacer for a connector in a method of manufacturing an article with
an electronic circuit according to a sixth embodiment of the
present invention;
[0047] FIG. 15 is an explanatory view showing the state of a mount
board with components mounted thereon after being vacuum-sucked
from a connector thereof in the method of manufacturing an article
with an electronic circuit according to the sixth embodiment of the
present invention;
[0048] FIG. 16 is a cross sectional view showing the connector and
the vacuum sucking connector for use in the method of manufacturing
an article with an electronic circuit according to the fifth
embodiment of the present invention;
[0049] FIGS. 17A, 17B, 17C, and 17D are, respectively, a
perspective view of a valve in the process of being coupled with a
connector of a mount board with components mounted thereon, an
explanatory view of the valve in an opened state, an explanatory
view of the valve in a closed state, and a perspective view of a
valve in a modified embodiment, each in a method of manufacturing
an article with an electronic circuit formed according to a seventh
embodiment of the present invention;
[0050] FIGS. 18A and 18B are, respectively, an explanatory view
showing a valve in an open state with a suction tube inserted into
a connector of a mount board with component mounted thereon, and an
explanatory view showing a valve in a closed state with the
aspirating tube extracted from the connector, in a method of
manufacturing an article with an electronic circuit according to an
eighth embodiment of the present invention;
[0051] FIG. 19 is a schematic explanatory view showing an article
with an electronic circuit having an elastic sheet according to
another embodiment of the present invention, in which space is
provided between the elastic sheet and a film and between the
elastic sheet and a board and components for easier understanding,
though close contacts therebetween are preferable in practice;
[0052] FIG. 20 is a schematic explanatory view showing an article
with an electronic circuit having an adhesion layer according to
another embodiment of the present invention, in which space is
provided between the adhesion layer and a film and between the
adhesion layer and a board and components for easier understanding,
though close contacts therebetween are preferable in practice;
[0053] FIG. 21 is a schematic explanatory view showing an article
with an electronic circuit having an adhesion layer in a connection
portion according to another embodiment of the present invention,
in which space is provided between the adhesion layer and a film
and between the adhesion layer and a board and components for
easier understanding, though close contacts therebetween are
preferable in practice; and
[0054] FIG. 22 is a schematic explanatory view showing an article
with an electronic circuit having an absorbent according to another
embodiment of the present invention, in which space is provided
between the absorbent and a film and between the absorbent and a
board and components for easier understanding, though close
contacts therebetween are preferable in practice.
DETAILED DESCRIPTION OF THE INVENTION
[0055] Before the description of the present invention proceeds, it
is to be noted that like parts are designated by like reference
numerals throughout the accompanying drawings. Embodiments of the
present invention will be described hereinafter with reference to
accompanying drawings.
[0056] A method of manufacturing an article with an electronic
circuit according to a first embodiment of the present invention
includes a step of printing or applying an electronic component
mounting bonding agent on electrodes of a circuit board 1 shown in
FIGS. 1 and 2, a step of bringing electronic components 2, . . . ,
2 close to the positions of the above electrodes through mechanical
application of pressure, and a step of fixing the components 2 on
the board 1 through heating, so that a components-mounted circuit
board 1 as shown in FIG. 2 is manufactured through the above steps.
The method further includes a step of, thereafter, packaging most
of the components-mounted circuit board 1 obtained by mounting the
components 2, . . . , 2 on the circuit board 1 with a cylindrical
film 3 shown in FIG. 3 for completing an article with an electronic
circuit 80 shown in FIG. 4B. It is noted that the article with an
electronic circuit 80 means a product which has a board 1 with the
electronic components provided thereon or a circuit-formed unit
with a circuit formed thereon and the electronic components, such
as casings of electrical appliances, electronic devices, arranged
thereon, covered with a film.
[0057] In the printing or applying step, the electronic component
mounting bonding agent, such as metallic solders or thermosetting
conductive adhesives, is printed or applied on each electrode of
the circuit board 1.
[0058] In the step of bringing the electronic components 2, . . . ,
2 close to the positions of the electrodes, each electronic
component 2 vacuum-picked up and held by a pickup head (unshown) or
the like is mechanically brought close to the corresponding
electrodes on the circuit board 1 with the electrodes located at
positions where the electronic components 2 are to be mounted using
the pickup head, and pressure is applied for attaching the
components.
[0059] In the fixing step, the above-stated solder is melted
through heating. Then, the electrodes of the electronic components
2, . . . , 2 placed on the circuit board 1 as shown above are bound
to the electrodes on the board 1 with the solder so as to fix the
placed electronic components 2, . . . , 2 on the board 1. It is
noted that reference numeral 2A in FIG. 2 represents a connector
among the electronic components 2.
[0060] In the packaging step, most of (approximately all of) both
the front and back surfaces of the board 1 with the electronic
components 2, . . . , 2 mounted thereon is inserted into the
cylindrical film 3 (see FIG. 4A) so that most of both the front and
back surfaces of the board 1 is covered and packaged with the film
3 (see FIG. 4B). It is noted that the cylindrical film refers to a
film in a state such that two confronting sides of two rectangular
sheet-like films are closed or integrated for continuity.
[0061] The cylindrical film 3 for packaging, if having a thickness
of less than 10 .mu.m, is poor in impact resistance and therefore
not desirable. If the film 3 has a thickness larger than 200 .mu.m,
the ability to follow (conform to) the external shape of the
electronic components is deteriorated, which generates large inner
space, and therefore results in no sealing effect. Consequently,
the film 3 having a thickness of 10 to 200 .mu.m achieves excellent
impact resistance and a sufficient sealing effect.
[0062] In the case where the cylindrical film 3 is composed of a
thermoplastic material, the board 1 is inserted into the film 3
(see FIG. 4A), and then the inside of the film 3 is decompressed
while the film 3 is heated. As a result, the heated and softened
film 3 is more likely to follow the surface of the board 1 and
components 2, . . . , 2 on the board (i.e., conform to the
contour), which decreases gases remained between the film 3 and the
surface of the board 1 and the components 2, . . . , 2 on the
board. This ensures a proper decompressing and tight closing
operation to maintain the decompressed condition.
[0063] When the board 1 is inserted into the film 3 for packaging
the board 1 therewith, if the internal pressure of the film 3 is
set to be 200 Torr or less, adhesiveness of the film 3 to the
electronic components 2, . . . , 2 is improved, which results in
reinforcement of fixing strength of the electronic components 2, .
. . , 2 to the board 1. As a result, excellent impact resistance is
obtained.
[0064] In the case where the cylindrical film 3 is composed of a
heat-shrinkable material, the board 1 is inserted into the
cylindrical film 3 from either one of the opening portions of the
cylindrical film 3 (see FIG. 4A). Thereafter, the film 3 is heated
to cause heat shrinkage, which brings the film 3 into close contact
with the circuit board 1 and the components 2, . . . , 2 thereon,
enabling the board 1 to be packaged (see FIG. 4B).
[0065] It is noted that one kind of cylindrical film 3 with a
length large enough to correspond to the boards 1 with various
target sizes for packaging may be prepared and cut out to be a
desired length depending on the size of a board 1 to be packaged
before packaging is performed. It is also possible that after the
board 1 is inserted into the cylindrical film 3, both of the
openings of the cylindrical film 3 are blocked and unnecessary
portions thereof are cut off for packaging the circuit board 1.
[0066] As stated above, according to the article with an electronic
circuit and the method of manufacturing the same in the first
embodiment, the following functions and effects can be
implemented.
[0067] For packaging boards with components mounted thereon by
inserting them into a bag, if various-sized products are packaged,
different-sized bags are prepared in advance and it is necessary to
select an appropriately sized bag according to the size of each
board and component. Contrary to this, the first embodiment of the
present invention makes it possible to cover an article with a
circuit (e.g. the board 1) with the cylindrical film 3, which
enables use of the same cylindrical film 3 for performing the
packaging operation even though various products having different
sizes are packaged. As a result, the generality is achieved and the
packaging operation is simplified and facilitated. In particular,
in the case where a rectangular cylindrical film 3 is used to
package a rectangular board 1, the board 1 is inserted into the
cylindrical film 3 so that a lengthwise direction of the board 1
may match with a lengthwise direction of the rectangular
cylindrical film 3 since rectangular boards 1 normally tend to vary
in size in their lengthwise direction. Accordingly, the cylindrical
film 3 becomes capable of corresponding to different-sized boards 1
only by changing the sealing position of the cylindrical film 3 in
the lengthwise direction.
[0068] Conventionally, in order to reinforce the bond strength of
conductive adhesives, there has been a separately-conducted method
to seal components on a board using a sealant, in which the sealant
is applied so as to cover the board and the components thereon.
However, sealing the components on the board with the sealant
brings about difficulty in later board repair including replacement
of components, as well as in recovery and recycle thereof. In
addition, this method requires 4 hours or more to harden sealing
resin as the sealant, which increases the time necessary for the
sealing operation. On the contrary, if the board 1 with the
electronic components 2, . . . , 2 mounted thereon is packaged with
the cylindrical film 3 based on the method of manufacturing an
article with an electronic circuit according to the first
embodiment, the cylindrical film 3 protects the electronic
components 2, . . . , 2 and reinforces the bond strength. As a
result, impact resistance is improved, and a simple operation of
unsealing the cylindrical film 3 easily enables repair of the board
1 and the components 2, as well as recovery and recycle of the
components 2. In addition, time taken for packaging the board 1
becomes, for example, 1 minute or less. Also, repackaging after
repair of the components 2 can be easily implemented.
[0069] In the method of sealing a board with silicon resin or
urethane resin or the like for the purpose of protecting the board
from moisture, dust, salt damage, and the like, there arises
difficulty, like the above case, in later board repair including
replacement of components, as well as in recovery and recycle of
the components. In addition, this method requires about 8 hours to
harden the sealing resin, which increases the time necessary for
the sealing operation. Contrary to this, if the board 1 is packaged
with the cylindrical film 3 as in the first embodiment, the board 1
can easily obtain moisture resistance, dust resistance, and salt
damage resistance with reliability. Further, a simple operation of
easily unsealing the cylindrical film 3 allows for various
operations including repair of the board 1 and the components 2,
which have been difficult to perform with the conventional sealing
method, and therefore allows various conventional issues to be
solved. It is noted that reference numeral 81 in FIG. 4B represents
a drop of water.
[0070] Next, description will be given of an article with an
electronic circuit and a method of manufacturing the same according
to a second embodiment of the present invention. The second
embodiment is different from the first embodiment in that a film 3
is heated before it is used to package a board 1, and two
sheet-like films 3A and 3B are substituted for the film 3.
[0071] More particularly, before the board 1 is packaged with the
films 3A and 3B, at least each two confronting sides of the
rectangle films 3A and 3B are held by a pair of rodlike
film-holding portions 11, 11 as shown in FIG. 5. In this state, the
films 3A and 3B are heated in upward and downward directions with
electrically heated wires 10a, 10a of heating apparatuses 10, 10 so
as to be softened. After the films 3A and 3B are softened, the
board 1 and the components 2, . . . , 2 on the board 1 are each
packaged with the films 3A and 3B so as to be covered therewith.
Consequently, the films 3A and 3B conform to the contour of the
board 1 and the components 2, . . . , 2 on the board 1 in an
improved manner, which decreases space between the board 1 and the
components 2, . . . , 2 on the board 1 and the films 3A and 3B. As
a result, efficient packaging can be performed in a short period of
time. It is noted that the edges of the films 3A and 3B are fixed
to each other through use of adhesives or through welding to
achieve a sealed condition or an approximately sealed
condition.
[0072] In the process of heating and softening the films 3A and 3B,
at least each two confronting sides of the films 3A and 3B are held
by a pair of rodlike film-holding portions 11, 11. However, for
stabilizing the posture of the films 3A and 3B during the process
of film softening, it is preferable that each of the four sides of
the films 3A and 3B are held. A means of softening the films 3A and
3B is not limited to the use of the heating wires 10a, 10a of the
heating apparatuses 10, 10, and therefore heating through hot wind
is also applicable. The films 3A and 3B may be heated in either
upward or downward direction, though heating in both the upward and
downward directions implements uniform softening of the films 3A
and 3B in a short period of time.
[0073] It is noted that one kind of sheet-like film 3A and 3B with
dimensions large enough to correspond to all the sizes of
packaging-target boards 1 may be prepared and cut out to desired
dimensions depending on the size of a board 1 to be packaged,
before packaging is performed. It is also possible that after the
board 1 is inserted between the sheet-like films 3A and 3B, four
sides of the sheet-like films 3A and 3B are tightly closed, and
unnecessary portions of the sheet-like films 3A and 3B are cut out
for packaging the circuit board 1.
[0074] According to the above-described second embodiment, the
following functions and effects can be implemented. For packaging
boards with components mounted thereon by inserting them into a
bag, if various products in which the size of boards and the
components varies are packaged, different-sized bags should be
prepared in advance and an appropriately-sized bag is selected
according to the size of each board and component. On the contrary,
the second embodiment of the present invention makes it possible to
cover an article with a circuit formed (e.g. the board 1) with the
sheet-like films 3A and 3B, enabling use of the same sheet-like
films 3A and 3B for performing the packaging operation even though
various products in which the size of the board 1 and the
components varies are packaged. As a result, generality is achieved
and the packaging operation is simplified and facilitated. In
particular, in the case where rectangular boards 1 vary in size not
only in their lengthwise direction but also in their shorter side
direction orthogonal to the lengthwise direction, a rectangular
board 1 is covered with one rectangular sheet-like film 3A or 3B
and then the sheet-like film 3A or 3B is fixed to the board.
Alternatively, both front and back surfaces of a rectangular board
1 are covered with two rectangular sheet-like films 3A and 3B and
then the sheet-like films 3A and 3B are fixed to each other.
Accordingly, a simple operation of changing the fixing position of
the sheet-like films 3A and 3B makes it possible to accommodate
different sized boards 1.
[0075] In addition, packaging the board 1 with sheet-like films 3A
and 3B enables easy and reliable achievement of moisture
resistance, dust resistance, and salt damage resistance of the
board 1. Further, a simple operation of unsealing the sheet-like
films 3A and 3B easily allows various operations including repair
of the board 1 and the components 2, which have been difficult to
perform with the conventional sealing method, and therefore enables
various conventional issues to be solved.
[0076] Next, description will be given of an article with an
electronic circuit and a method of manufacturing the same according
to a third embodiment of the present invention. The third
embodiment is different from the first and second embodiments in
that the front and back surfaces of a board 1 are each
vacuum-molded in sequence with two sheet-like films 3A and 3B and
brought into close contact therewith. The third embodiment will be
described with reference to FIG. 6.
[0077] FIG. 6 shows a suction box 14 with the shape of a rectangle
box, and whose central bottom is connected to a vacuum pump 15. On
a rectangular frame-like supporting projection 14b inside a
deposition space 14a in the suction box 14, there is fixed a
deposition board 17, on which a board 1 is placed through a
plurality of rodlike spacers 16, . . . , 16. A number of
penetrating holes 17a, . . . , 17a are formed on the deposition
board 17.
[0078] At least two confronting sides of a film 3A covering the
front surface side of the board 1 are held by one pair of rodlike
film holding portions 11, 11. In the heated and softened condition,
the film 3A is placed on an upper opening of the suction box 14
with the board 1 set therein. At this point, care is taken so as to
prevent generation of space between the film 3A and the suction box
14 as much as possible.
[0079] Next, the vacuum pump 15 is driven to execute suction from
the bottom portion of the deposition space 14a in the suction box
14 through use of the vacuum pump 15. More particularly, a gas
(e.g. air) in the deposition space 14a with the board 1 set therein
is sucked to the side of the vacuum pump 15 through the penetrating
holes 17a, . . . , 17a of the deposition board 17. Due to the
suction box 14 in contact with the film 3A, the deposition space
14a with the board 1 set therein is sealed. Further, continuous
driving of the vacuum pump 15 to suck the air in the deposition
space 14a deforms the softened film 3A and draws it into the
deposition space 14a. As a result, as shown in FIG. 7, the film 3A
comes into close contact with the surface of the board 1 such that
it follows (conforms to) the surface of the board 1. The board 1 is
floated from the deposition board 17 with the presence of the
spacers 16, . . . , 16, so that the film 3A can be bent from edges
of the board 1 into the back surface, i.e. the lower surface side
of the board 1.
[0080] After that, the board 1 is placed upside down so that the
back surface of the board 1 having been positioned to face the
lower side of suction box 14 is changed to be the front side. Then,
the board 1 is placed on the deposition board 17 inside the
deposition space 14a through the spacers 16, . . . , 16. Then,
another film 3B is vacuum-molded on the back surface of the board 1
based on the same process as used to cover the front surface side
of the board with the film 3A. As a result, the softened film 3B is
deformed and drawn into the deposition space 14a of the suction box
14. Consequently, as shown in FIG. 7, the film 3B comes into close
contact with the back surface of the board 1 such that it follows
the back surface of the board 1. This enables tight sealing of both
the front and back surfaces of the board 1 with two films 3A and
3B. FIG. 8 shows the board 1 of FIG. 2 packaged with the films 3A
and 3B. FIG. 9A is a cross sectional view showing the thus-packaged
board 1. As enlarged in FIG. 9B, in the edges of the board 1, an
edge portion 3b of the upper film 3B is laid on top of an edge
portion 3a of the upper side of the film 3A. These edges are fixed
to each other through molding and the like, by which the sealed
condition is maintained.
[0081] According to the third embodiment, two films may vary in
thickness and materials. For example, a thick film is disposed on
one side of a board having a lead head of an insertion component
for inserting a lead into a penetrating hole of the board to obtain
electrical connection. A thin film is disposed on the other side of
the board having a heat generating component or a reflow component.
This implements further improvement of the functions.
[0082] Next, description will be given of an article with an
electronic circuit and a method of manufacturing the same according
to a fourth embodiment of the present invention. The fourth
embodiment is different from the third embodiment in that, as shown
in FIG. 10, two films 3A and 3B are placed so as to confront the
front and the back surfaces of a board 1 in upward and downward
directions, enabling simultaneous tight closing and packaging of
the front and the back surfaces of the board 1. In this case, at
least two confronting sides of the film 3A are held by a pair of
rodlike film holding portions 21A, 21A (preferably four sides
thereof are held by two pairs of the film holding portions), while
at least two confronting sides of the film 3B are held by a pair of
rodlike film holding portions 21B, 21B (preferably four sides
thereof are held by two pairs of the film holding portions). Next,
with the board 1 interposed between the film 3A held by the film
holding portions 21A, 21A and the film 3B held by the film holding
portions 21B, 21B, each film holding portion 21A and each film
holding portion 21B are brought in close contact with each other
without causing leakage of air therebetween. As a result, a space
82 which is surrounded by the film 3A, the film holding portions
21A, 21A, the film 3B, and the film holding portions 21B, 21B, and
which is accommodating the board 1 becomes an enclosed space.
Through use of a suction pipe 21a or 21b interposed between either
or both of the film holding portions 21A and 21B, air in the space
82 is vacuum-sucked by a vacuum pump. On the film holding portion
21A or 21B, there is mounted a board supporting portion 21C
projecting toward the board 1. The board supporting portion 21C is
connected to the film holding portions 21A and 21B through the use
of a connector 2A of the board 1 or the like to support the board
1. The board supporting portion 21C supports the board 1 in the
middle of the space 82 through the connector 2A.
[0083] According to the fourth embodiment, both the front and the
back sides of the board 1 can be tightly closed with two sheet-like
films 3A and 3B with one suction process, resulting in increased
productivity.
[0084] Description will be now given of an article with an
electronic circuit formed and a method of manufacturing the same
according to a fifth embodiment of the present invention with
reference to FIGS. 12 and 13. The fifth embodiment is different
from the previous embodiment in that, as shown in FIG. 13, suction
is executed through the use of a connector 2A mounted on the board
1.
[0085] The connector 2A mounted on the board 1 normally has air
pathways. After a vacuum-sucking connector 31 is attached to the
connector 2A of the board 1, the board 1 is inserted into a
cylindrical film 3 or in between sheet-like films 3A and 3B. Then,
the cylindrical film 3 or the sheet-like films 3A and 3B
surrounding the board 1 are tightly closed, and air is sucked from
the vacuum-sucking connector 31 through a suction pipe 30 by a
vacuum pump or the like. Thus, packaging is performed as shown in
FIG. 13. The vacuum-sucking connector 31 is equipped with at least
one, and preferably a number of, suction pipes 31a, . . . , 31a to
perform suction smoothly as shown in FIG. 16.
[0086] It is noted that the connector 2A may be equipped with at
least one and preferably a number of suction holes 40, . . . , 40
corresponding to the vacuum-sucking connector 31 to perform
smoother suction.
[0087] Although the board 1 is tightly closed only with a
cylindrical film 3 or sheet-like films 3A and 3B in FIG. 12, tight
closing may be performed by pressing the film using a block and the
like.
[0088] According to the above-stated fifth embodiment, when the
degree of inner vacuum is decreased by secular change and the like,
the degree of vacuum can be restored through suction with use of
suction pipes 31a, . . . , 31a, without cutting the film.
[0089] Description will be now given of an article with an
electronic circuit and a method of manufacturing the same according
to a sixth embodiment of the present invention. The sixth
embodiment is different from the previous embodiment in that, as
shown in FIG. 14, a cylindrical or sheet-like heat-shrinkable film
3D is used.
[0090] It is difficult to predict the shape of a heat-shrinkable
film 3D after its shrinkage. Therefore, it is necessary in the
connector 2A on the board to secure space for inserting a connector
for use in supplying power or sending signals to the board 1
through the connector 2A. Consequently, a spacer 35 dedicated to a
connector is inserted to the connector 2A of the board 1. Then, the
film 3D is heated so that the film 3D is heat-shrunken and conforms
to the board 1. After that, an unnecessary portion of the film 3D
is cut off and the spacer 35 dedicated to the connector is removed,
by which the board 1 can be packaged while the space for inserting
the connector is secured as shown in FIG. 15.
[0091] According to the above-stated sixth embodiment, even with
the use of a heat-shrinkable film 3D, the spacer 35 dedicated to a
connector is inserted in the connector 2A of the board 1.
Therefore, when the film 3D is heat-shrunken and follows the board
1, improvident insertion of the film 3D into the connector 2A is
prevented, and therefore the board 1 can be packaged while the
space for the connector insertion is secured.
[0092] Description will be now given of an article with an
electronic circuit and a method of manufacturing the same according
to a seventh embodiment of the present invention. The seventh
embodiment is different from the previous embodiment in that, as
shown in FIGS. 17A to 17D, a valve 44 is mounted on the suction
hole 40 in the side of the board or the film to maintain the degree
of vacuum inside a package.
[0093] FIG. 17A shows the valve 44. The valve 44 fixed to the
suction hole 40 is composed of an elastic material such as rubber.
The valve 44 creates an open state (see FIG. 17B) in which a round
central portion 42 is elevated from a circular peripheral portion
41 surrounding the central portion 42, by which a hole 43 and space
are generated between the central portion 42 and the circular
portion 41. A closed state (see FIG. 17C) can also be created, in
which the round central portion 42 is in close contact with the
circular peripheral portion 41 surrounding the central portion 42
so that no space is generated between the central portion 42 and
the circular portion 41.
[0094] Accordingly, in the suction hole 40, execution of vacuum
suction elevates the round central portion 42 from the circular
peripheral portion 41 surrounding the central portion 42, by which
the hole 43 and the space are generated between the central portion
42 and the circular portion 41. This creates the open state (see
FIG. 17B), which allows suction of air from the side of the board.
On the other hand, upon termination of the sucking operation, the
round central portion 42 comes in close contact with the circular
peripheral portion 41 surrounding the central portion 42 by
atmospheric pressure so that no space is generated between the
central portion 42 and the circular portion 41. This creates the
closed state (see FIG. 17C), preventing air from entering inside of
the film from outside.
[0095] Execution of vacuum suction may be implemented with the
valve 44 which creates the open state (see FIG. 17B) in which the
round central portion 42 is elevated from the circular peripheral
portion 41 surrounding the central portion 42, by which the space
is generated between the central portion 42 and the circular
portion 41. The vacuum suction may also be generated with a valve
45 shown in FIG. 17D, in which an incision is formed in an elastic
round member, which elevates a part of a round central portion 47
from a circular portion 46 surrounding the central portion 47 while
making it inclined, and thereby generates space between the central
portion 47 and the circular portion 46.
[0096] According to the above-stated seventh embodiment, the valve
44 is provided in the suction hole 40 in the side of the board or
the film, which prevents air from entering inside a package, and
maintains the degree of vacuum in the package for a long period of
time. Further, if the degree of vacuum in the package is decreased
due to internal gas generation and the like, the degree of vacuum
can be restored through re-suction without replacement of the
film.
[0097] Next, a description will be given of an article with an
electronic circuit and a method of manufacturing the same according
to an eighth embodiment of the present invention. The eighth
embodiment is different from the previous embodiment in that, as
shown in FIGS. 18A and 18B, a vacuum-sucking connector 31 is
inserted into a connector 2A of the board 1, so that a suction pipe
31a of the vacuum-sucking connector 31 is inserted into a suction
hole 40 of the connector 2A for forced opening of a valve 50 in the
suction hole 40.
[0098] As shown in FIG. 18A, the valve 50 is composed of a
plurality of elastic pieces 51, 51. Normally, the elastic pieces
51, 51 are overlaid on each other by elasticity thereof to allow
tight closing. When the top portion of the suction pipe 31 a
separates the plurality of the elastic pieces 51, 51, a space is
generated between the elastic pieces 51 and 51, which makes the
valve 50 open. In this state, a sucking operation can be executed
through the suction pipe 31a. Upon extraction of the top portion of
the suction pipe 31a, the elastic pieces 51, 51 are overlaid on
each other by elasticity thereof so that tight closing is
achieved.
[0099] According to the above-stated eighth embodiment, the valve
50 is provided in the suction hole 40 in the side of the board or
the film, which prevents air from entering inside a package
maintains the degree of vacuum in the package for a long period of
time. Further, if the degree of vacuum in the package is decreased
due to internal gas generation and the like, the degree of vacuum
can be restored through re-suction without replacement of the
film.
[0100] In the above-described first to eighth embodiments,
materials usable as film 3, 3A, 3B, and 3D, include prestretched
polyethylene terephthalate (PET) (thermal deformation type) where
water absorptivity (waterproof property) is 0.3%, water-vapor
permeability (dampproofness) is 28 g/m.sup.2/24 hr., an oxygen
transmission rate (oxide resistance) is 3 cc/m.sup.2/hr./atm, and
heat conductivity (heat dissipation) is 6.7.times.10.sup.-4
cal/sec.multidot.cm .degree. C. Another usable material may be
drawn polystyrene where water absorptivity (waterproof property) is
0.05%, water-vapor permeability (dampproofness) is 100 g/m.sup.2/24
hr., an oxygen transmission rate (oxide resistance) is 300
cc/m.sup.2/hr./atm, and heat conductivity (heat dissipation) is
6.7.times.10.sup.-4 cal/sec.multidot.cm .degree. C. Another usable
material may be drawn nylon where water absorptivity (waterproof
property) is 10%, water-vapor permeability (dampproofness) is 130
g/m.sup.2/24 hr., an oxygen transmission rate (oxide resistance) is
2 cc/m.sup.2/hr./atm, and heat conductivity (heat dissipation) is
6.7.times.10.sup.-4 cal/sec.multidot.cm .degree. C. Another usable
material may be PE where water absorptivity (waterproof property)
is 0.02%, water-vapor permeability (dampproofness) is 20
g/m.sup.2/24 hr., an oxygen transmission rate (oxide resistance) is
250 cc/m.sup.2/hr./atm, and heat conductivity (heat dissipation) is
6.7.times.10.sup.-4 cal/sec.multidot.cm .degree. C. Another usable
material may be drawn polypropylene (PP) where water absorptivity
(waterproof property) is 0.01%, water-vapor permeability
(dampproofness) is 8 g/m.sup.2/24 hr., an oxygen transmission rate
(oxide resistance) is 100 cc/m.sup.2/hr./atm, and heat conductivity
(heat dissipation) is 6.7'10.sup.-4 cal/sec.multidot.cm .degree. C.
In addition, heat-shrinkable type polyethylene terephthalate (PET)
is also usable.
[0101] The method of manufacturing an article with an electronic
circuit and the same manufactured by the method according to the
embodiments of the present invention are applicable to, for
example, circuit boards for use in base stations for
telecommunication, air conditioners, washing machines, gas meters,
various outdoor devices, and various AV (audio visual) apparatuses
usable outdoors.
[0102] It should be understood that the present invention is not
limited to the embodiments disclosed, but is capable of numerous
other modifications.
[0103] One example is to place a sheet, composed of a shielding
material such as copper and aluminum for preventing electromagnetic
waves, on top of a board with components mounted thereon and then
to package the board with the film. In this case, in addition to
the above-disclosed functions and effects, an electromagnetic
shielding effect can be implemented. As the shielding material, a
shielding material in which an OH base of nylon is replaced with Ag
is also usable.
[0104] Further, composing the above films 3, 3A, 3B, and 3D with
transparent or translucent visible materials makes the board 1 and
the electronic components 2, . . . , 2 and 2A mounted on the board
1 visible, which facilitates maintenance, repair, and recycling
operations. In the case of the board 1 having an LED and the like
in particular, use of the transparent films 3, 3A, 3B, and 3D are
preferable for increasing visibility of the LED and the like.
[0105] In addition, as shown in FIG. 19, an elastic sheet 70 is
provided between the films 3, 3A, 3B, and 3D and the components 2,
. . . , 2, and 2A, or the board 1, so that a shock absorbing
function can be imparted to the article with an electronic circuit,
resulting in further improvement of impact resistance of the board
1, components 2, . . . , 2, and 2A. In this case, an elastic sheet
is preparatorily attached to or integrated into the surface of the
film confronting the components 2, . . . , 2, and 2A or the board,
which implements simultaneous disposition of the elastic sheet and
the film, resulting in increased productivity.
[0106] Further, as shown in FIG. 20, an adhesion layer 71 is
provided in the inner surface of the films 3, 3A, 3B, and 3D for
adhering the films 3, 3A, 3B, and 3D to the components 2, . . . ,
2, and 2A, or the board 1. This makes it possible to prevent the
films 3, 3A, 3B, and 3D from being removed from the electronic
components 2, . . . , 2, 2A, or the board 1 even when the degree of
vacuum in the films 3, 3A, 3B, and 3D is degraded by air and the
like entering inside the films 3, 3A, 3B, and 3D. As a result, the
films 3, 3A, 3B, and 3D are capable of maintaining the protection
of the board 1 and the components 2, . . . , 2, and 2A. The
adhesion layer 71 may be obtained by applying adhesives like dots,
a sheet, or stripes.
[0107] As shown in FIG. 21, in the vicinity of a connecting section
(the vicinity of components connecting to the outside) on the board
1 including the vicinity of a connector 2A, the vicinity of an
external output terminal such as earphone jacks, the vicinity of an
input terminal, the vicinity of a power terminal, and the vicinity
of a battery holder, the films 3, 3A, 3B, and 3D are brought into
close contact with the connecting section through use of an
adhesive 72 such as sealing agents. This makes it possible to
prevent damage on a sealed state of the films 3, 3A, 3B, and 3D at
the vicinity of the connecting section.
[0108] Further, it is also possible to provide the films 3, 3A, 3B,
and 3D with an ability to allow gases generated from flame
retarders and solder flux used in the board 1 or the components 2,
. . . , 2, or 2A, and moisture generated from the board 1 made of
paper phenol to pass from inside to outside but to prevent moisture
and dust from invading to the inside of the films 3, 3A, 3B, and 3D
from the outside. Consequently, the films 3, 3A, 3B, and 3D
covering the board 1 can be protected for a long period of time
from being expanded by gases or moisture generated from the board
1, components 2, . . . , 2, or solder flux, and thereby protected
from suffering a deteriorated degree of vacuum, or breakage.
Materials having such function include PTFE
(polytetrafluoroethylene) (product name: GORE-TEX.RTM.).
[0109] It is also possible that the edges of the films 3, 3A, 3B,
and 3D are welded to package the board 1 in a sealed condition. The
board 1 is then unsealed through cutting of the welded portions at
the edges of the films 3, 3A, 3B, and 3D for required operations,
such as adjustment of connection to external circuits or the
components 2, . . . , 2, or 2A after which the edges of the films
3, 3A, 3B, and 3D are attached again to each other with use of a
sealing material to be sealed again.
[0110] It is also possible as shown in FIG. 22 to provide inside
the films 3, 3A, 3B, and 3D an absorbent 73 such as desiccants and
activated carbon for absorbing gases generated from flame retarders
and solder flux used in the board 1, the components 2, . . . , 2,
or 2A as well as moisture generated from the board 1 made of paper
phenol. Consequently, the films 3, 3A, 3B, and 3D covering the
board 1 can be protected for a long period of time from being
expanded by gases or moisture generated from the board 1,
components 2, . . . , 2, or 2A or solder flux, and thereby be
protected from suffering a deteriorated degree of vacuum, or
breakage.
[0111] Further, it is possible that the board 1 is heated in
advance to a temperature equal to or higher than the temperature at
which the films 3, 3A, 3B, and 3D are softened, and lower than the
temperature at which the films 3, 3A, 3B, and 3D are melted, and
within a range that a bonding agent to bind the board 1 and the
components 2, . . . , 2, and 2A is not melted (e.g. 100 to
130.degree. C.). After that, the board 1 is packaged with the films
3, 3A, 3B, and 3D. Consequently, the films 3, 3A, 3B, and 3D are
softened upon contact with the heated board 1, which allows the
films 3, 3A, 3B, and 3D to easily conform to the board 1 and the
components 2, . . . , 2 and 2A. Materials having such function
include PET, ABS, and PEN (polyethylene naphthalate).
[0112] It should be understood that among the above-described
various embodiments, some embodiments may be appropriately combined
to implement various effects peculiar to each embodiment.
[0113] Hereinbelow, a detailed description will be given of the
method of manufacturing the article with an electronic circuit
formed according to the above-disclosed embodiments with reference
to examples of the above-disclosed embodiments of the present
invention and comparative examples thereof.
[0114] (Circuit Boards)
[0115] On electrodes of a glass epoxy board (dimensions: 95
mm.times.140 mm.times.0.8 mm), a conductive adhesive (contents:
silver-filled epoxy resin system) was printed, and a chip capacitor
component (dimensions: 1.0 mm.times.0.5 mm.times.0.5 mm) was
mounted on the above specified position with use of an electronic
component mounting apparatus (unshown). The board was then passed
through a reflow furnace so that the conductive adhesive was
heat-hardened, by which electrical bonding between the board
electrodes and the component electrodes was completed.
[0116] Next, the circuit board obtained by the above process was
subjected to processing as shown below to produce samples. The
samples were produced with materials and conditions shown
below:
[0117] (Film Materials)
[0118] Film A: nylon 6 (thermoplastic resin made by Toray
Industries, Inc.)
[0119] Film B: ABS (thermoplastic resin made by Taihei Chemicals
Limited)
[0120] Film C: PET (thermoplastic resin made by Teijin Chemicals
Ltd.)
[0121] Film D: silicone rubber (made by Toray Industries, Inc., Dow
Coming Corp.)
[0122] Film E: polycarbonate (thermoplastic resin made by
Tsutsunaka Plastic Industry Co., Ltd.)
[0123] (Film States)
[0124] A packaging state "b" represents packaging with a
cylindrical film, whereas a packaging state "c" represents
packaging with two sheet-like films.
[0125] The samples (working examples 1 to 5) were manufactured
under the conditions shown in Table 1 below.
EXAMPLES 1 TO 5
[0126]
1 TABLE 1 Working example 1 2 3 4 5 Board Packaged by Film Film
Film Film Film Film Thickness (mm) 125 100 100 100 100 Film
Material A B B C C Film State b b b b b Internal Pressure When 100
150 10 (Heat (Heat Depressed (Torr) shrunken) shrunken)
Comparative Examples 1 to 8
[0127] The samples (comparative examples 1 to 8) were manufactured
under the conditions shown in Table 2 below.
2 TABLE 2 Comparative Example 1 2 3 4 5 6 7 8 Board Urethane Film
Film Film Film Film Film Film Packaged sealing by Film -- 8 300 100
100 100 100 100 Thickness (mm) Film -- B B D B B E C Material Film
State -- b b b c b b c Internal -- 100 100 Depression Depression
300 (Heated) (Heated) Pressure unavailable unavailable When
Depressed (Torr)
[0128] Various properties of the samples obtained through the above
processes were measured. The measurement was made as follows:
[0129] 1) Impact resistance: samples were dropped from a 1 m-high
position, and it was observed if any component was missed or not.
The samples without chipping were determined to be good, whereas
those with chipping were determined to be NG.
[0130] 2) Packaging (sealing) time: the period of time taken for a
packaging or sealing process in manufacturing the samples was
measured.
[0131] 3) Component recovery: unpacking of the samples was
conducted for the purpose of determining if the components could be
removed from the board. The samples that could be unpacked without
damaging the components were determined to be good, where those
with damage to the components were determined to be NG.
[0132] 4) Water absorption: weight (w.sub.0) of the samples were
measured, and then the samples were left in a 60.degree. C. 90% RH
constant-temperature high-humidity bath for 1000 hours. After the
samples were extracted from the bath, the weight (w.sub.1) thereof
was measured again. The water absorption was obtained with
{(w.sub.1-w.sub.0)/w.sub.0}- .times.100=water absorption (%).
[0133] The result of the property measurement of each sample is
shown in Table 3.
3 TABLE 3 Packaging Impact (Sealing) Component Water Resistance
Time Recovery Absorption Working Ex- Good 1 min. Good 0.45 ample 1
Working Ex- Good 0.8 min. Good 0.51 ample 2 Working Ex- Good 1.5
min. Good 0.29 ample 3 Working Ex- Good 0.8 min Good 0.44 ample 4
Working Ex- Good 0.8 min Good 0.39 ample 5 Comparative Ex- NG 8 hr.
NG 0.30 ample 1 Comparative Ex- NG 1 min. Good 0.45 ample 2
Comparative Ex- Good 1 min. Good 1.10 ample 3 Comparative Ex- Good
packaging -- -- ample 4 unavailable Comparative Ex- NG packaging --
-- ample 5 unavailable Comparative Ex- Good 0.6 min. Good 1.11
ample 6 Comparative Ex- NG packaging -- -- ample 7 unavailable
Comparative Ex- NG packaging -- -- ample 8 unavailable
[0134] Table 3 indicates that the articles with an electronic
circuit manufactured according to the working examples
corresponding to the embodiments of the present invention enables
packaging in a short period of time, has excellent impact
resistance, enables stable recovery of components, and has
excellent water absorption.
[0135] Conventionally, in packaging boards with components mounted
thereon by inserting them into a bag, if the size of the boards and
the components varies, different sized bags should be prepared in
advance and an appropriately sized bag should be selected according
to each size of the boards and components.
[0136] Contrary to this, the present invention makes it possible to
cover an article with a circuit (e.g. a board) with sheet-like
films or a cylindrical film, which enables use of the same
sheet-like films or the cylindrical film for packaging various
products in which the size of the board and the components varies.
As a result, generality is achieved and a packaging operation is
simplified and facilitated. For example, in the case where a
rectangular cylindrical film is used to package a rectangular
board, the board is inserted into the cylindrical film so that a
lengthwise direction of the board aligns with a lengthwise
direction of the cylindrical film since the boards normally tend to
vary in size in their lengthwise directions. Accordingly, the
cylindrical film becomes capable of corresponding to different
sized boards only by changing the sealing position of the
cylindrical film in the lengthwise direction. In addition, in the
case where rectangular boards vary in size not only in lengthwise
direction but also in short side direction orthogonal to the
lengthwise direction, a rectangular board is covered with one
rectangular sheet-like film and then the film is fixed to the
board, or both front and back surfaces of the rectangular board are
covered with two rectangular sheet-like film(s) and then the
sheet-like films are fixed to each other. Accordingly, a simple
operation of changing the fixing position of the sheet-like films
makes it possible to correspond to different sized boards.
[0137] As a result, the present invention is capable of
corresponding to different sized boards 1, achieving generality,
being packaged in a short period of time, increasing impact
resistance, and facilitating recovery and recycling of components
2, . . . , 2 and 2A, the board 1, and the like. In addition, the
board and the components covered by the film ensure protection of
circuits, prevent dew formation, prevent dirt and dust from being
mixed or accumulated inside the package, prevent insects such as
cockroaches and ants from invading (prevention of corrosion due to
formic acid), and prevent salt damage due to salty winds, thereby
making it possible to provide articles with electronic circuits
formed with excellent reliability with respect to in humidity
resistance and the like.
[0138] Further, composing the above films with transparent or
translucent visible materials allows the board and the electronic
components mounted on the board to be made visible, which
facilitates maintenance, repair, and recycling operations.
[0139] In addition, an elastic sheet is provided in between the
films and the components or the board, so that the elastic sheet
has a shock absorbing function which can be imparted to the article
with an electronic circuit. This arrangemnt results in further
improvement regarding impact resistance of the board and the
components.
[0140] In addition, an adhesion layer is provided in the inner
surface of the films for adhering the films to the components or
the board. This makes it possible to prevent the films from being
removed from the electronic components or the board even when the
degree of vacuum in the films is degraded by air and the like
entering inside thereof. As a result, the films become capable of
maintaining a function of protecting the board and the
components.
[0141] Further, in the vicinity of a connecting section on the
board including the vicinity of a connector, the vicinity of an
external output terminal such as earphone jacks, the vicinity of an
input terminal, the vicinity of a power terminal, and the vicinity
of a battery holder, the films are brought into close contact with
the connecting section through the use of adhesives. This makes it
possible to prevent damage in a sealed state of the films.
[0142] Further, it is also possible for the films to allow gases
generated from flame retarders and solder flux used in the board
and the components, as well as moisture generated from the board
made of paper phenol etc., to pass from inside to outside while
still preventing moisture and dust from invading the inside of the
films from the outside. Consequently, the films covering the board
can be protected for a long period of time by preventing expansion
by gases or moisture generated from the board, the components, or
solder flux, and thereby protect the package from suffering a
deteriorated degree of vacuum or breakage.
[0143] It is also possible that the films are welded to package the
board in a sealed condition, and then the board is unsealed by
cutting the welded portions of the films to accomplish operations
such as connection to external circuits or adjustment of the
components. After being unsealed the films are attached again to
each other with use of a sealing material so as to be sealed
again.
[0144] It is also possible to provide an absorbent, such as
desiccants and activated carbon, inside the film for absorbing
gases generated from flame retarders and solder flux used in the
board and the components as well as moisture generated from the
board made of paper phenol, etc. Consequently, the films covering
the board can be protected for a long period of time an prevented
from being expanded by gases or moisture generated from the board,
the components, or solder flux. Thereby, the package is protected
from suffering a deteriorated degree of vacuum, or breakage.
[0145] Further, it is possible that the board 1 is previously
heated to a temperature equal to or higher than the temperature at
which the cylindrical film or sheet-like films are softened, and
lower than the temperature at which the cylindrical film or
sheet-like films are melted, and to a temperature within a range
that a bonding agent to bind the board and the components is not
melted. After that, the board 1 is packaged with the cylindrical
film or sheet-like films. Consequently, the cylindrical film or
sheet-like films are softened upon contact with the heated board,
which allows the cylindrical film or sheet-like films to easily
confrom to the contour of the board.
[0146] Although the present invention has been fully described in
connection with the preferred embodiments thereof with reference to
the accompanying drawings, it is to be noted that various changes
and modifications are apparent to those skilled in the art. Such
changes and modifications are to be understood as included within
the scope of the present invention as defined by the appended
claims unless they depart therefrom.
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