U.S. patent application number 12/659179 was filed with the patent office on 2010-09-16 for apparatus and method for fabricating bonded substrate.
This patent application is currently assigned to Fujitsu Limited of Kawasaki, Japan. Invention is credited to Tsukasa Adachi, Koji Hashizume, Takao Kojima, Yosimasa Miyajima, Takanori Muramoto, Takuya Ohno.
Application Number | 20100230030 12/659179 |
Document ID | / |
Family ID | 28035420 |
Filed Date | 2010-09-16 |
United States Patent
Application |
20100230030 |
Kind Code |
A1 |
Muramoto; Takanori ; et
al. |
September 16, 2010 |
Apparatus and method for fabricating bonded substrate
Abstract
A bonded-substrate fabricating apparatus capable of reducing
defective bonded substrates fabricated. A transfer robot sucks the
outer edge area of the bottom surface of a substrate and spouts gas
toward the bottom surface of the substrate to carry the substrate
into a vacuum process chamber of a press machine while keeping the
substrate horizontally. A press plate holds the substrate, which is
held by the transfer robot, by suction.
Inventors: |
Muramoto; Takanori;
(Kasugai, JP) ; Ohno; Takuya; (Kasugai, JP)
; Adachi; Tsukasa; (Kasugai, JP) ; Hashizume;
Koji; (Kasugai, JP) ; Miyajima; Yosimasa;
(Kasugai, JP) ; Kojima; Takao; (Kasugai,
JP) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700, 1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
Fujitsu Limited of Kawasaki,
Japan
|
Family ID: |
28035420 |
Appl. No.: |
12/659179 |
Filed: |
February 26, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11254741 |
Oct 21, 2005 |
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12659179 |
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10347625 |
Jan 22, 2003 |
7137427 |
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11254741 |
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Current U.S.
Class: |
156/60 |
Current CPC
Class: |
G02F 1/1333 20130101;
G02F 1/1341 20130101; H01L 21/67092 20130101; B32B 38/18 20130101;
B32B 2457/202 20130101; B32B 37/0015 20130101; B32B 2457/20
20130101; B32B 2038/1891 20130101; G02F 1/13415 20210101; Y10T
156/10 20150115; G02F 1/133354 20210101; Y10T 156/1744 20150115;
B32B 38/1858 20130101; B32B 2309/68 20130101 |
Class at
Publication: |
156/60 |
International
Class: |
B32B 37/02 20060101
B32B037/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 19, 2002 |
JP |
2002-076173 |
Claims
1. A method of operating an apparatus for bonding upper and lower
substrates to one another to fabricate a bonded substrate, wherein
the apparatus includes upper and lower holding plates, arranged in
a process chamber to face each other, to hold an upper surface of
the upper substrate and a lower surface of the lower substrate,
respectively; a transfer robot to transfer the upper substrate to
and from the process chamber; a chuck mechanism, which is movable
up and down with respect to the upper holding plate, the chuck
mechanism including chuck portions each movable up and down
individually; and a controller coupled to the upper and lower
holding plates, the transfer robot, and the chuck mechanism, the
method comprising: the controller causing the chuck mechanism to
chuck the upper substrate, which is distanced from and located
below the upper holding plate and is on the transfer robot, to
transfer the upper substrate from the transfer robot to the chuck
mechanism; the controller causing the chuck mechanism to place the
chucked upper substrate to a location where the chucked upper
substrate comes close to, but not in contact with, the upper
holding plate while holding the chucked upper substrate in a flat
state; the controller causing the upper holding plate to apply at
least one of suction and electrostatic force to the upper substrate
that is in the flat state and is placed at the location where the
upper substrate comes close to, but not in contact with, the upper
holding plate, to hold the upper surface of the upper substrate;
and thereafter the controller causing the upper and lower holding
plates to bond a lower surface of the upper substrate and an upper
surface of the lower substrate to each other.
2. The method according to claim 1, further comprising: the
controller causing the chuck portions of the chuck mechanism to
move up and down in vertically extending through passages of the
upper holding plate.
3. The method according to claim 1, further comprising: the
controller causing the chuck portions of the chuck mechanism to
individually and independently chuck the substrate.
4. The method according to claim 2, further comprising: the
controller causing the chuck portions of the chuck mechanism to
individually and independently chuck the substrate.
5. The method according to claim 1, wherein the upper holding plate
is located above the lower holding plate.
6. A method of operating an apparatus for bonding upper and lower
substrates to one another to fabricate a bonded substrate, wherein
the apparatus includes upper and lower holding plates, arranged in
a process chamber to face each other, to hold an upper surface of
the upper substrate and a lower surface of the lower substrate,
respectively; a transfer robot to transfer the upper substrate to
and from the process chamber; a chuck mechanism, which is movable
up and down with respect to the upper holding plate, the chuck
mechanism including chuck portions each movable up and down
individually; and a controller coupled to the upper and lower
holding plates, the transfer robot, and the chuck mechanism, the
method comprising: the controller causing the chuck mechanism to
chuck the upper surface of the upper substrate, which is distanced
from and located below the upper holding plate and is on the
transfer robot, to correct bending of the upper substrate when
transferring the upper substrate from the transfer robot to the
chuck mechanism; the controller causing the chuck mechanism to
place the bend-corrected, chucked upper substrate to a location
where the bend-corrected, chucked upper substrate comes close to,
but not in contact with, the upper holding plate; the controller
causing the upper holding plate to apply at least one of suction
and electrostatic force to the bend-corrected upper substrate that
is placed at the location where the bend-corrected upper substrate
comes close to, but not in contact with, the upper holding plate,
to receive the bend-corrected upper substrate from the chuck
mechanism; and thereafter the controller causing the upper and
lower holding plates to bond a lower surface of the upper substrate
and an upper surface of the lower substrate to each other.
7. A method for bonding upper and lower substrates to one another
to fabricate a bonded substrate, the method comprising:
transferring, with a transfer robot, an upper substrate and a lower
substrate to a process chamber; holding, with a lower holding
plate, the lower substrate; chucking, with a chuck mechanism, the
upper substrate, which is distanced from and located below an upper
holding plate and is on the transfer robot, to transfer the upper
substrate from the transfer robot to the chuck mechanism; placing,
with the chuck mechanism, the chucked upper substrate to a location
where the chucked upper substrate comes close to, but not in
contact with, the upper holding plate while holding the chucked
upper substrate in a flat state; applying, with the upper holding
plate, at least one of suction and electrostatic force to the upper
substrate that is in the flat state and is placed at the location
where the upper substrate comes close to, but not in contact with,
the upper holding plate, to hold the upper surface of the upper
substrate; and thereafter bonding, with the upper and lower holding
plates, a lower surface of the upper substrate and an upper surface
of the lower substrate to each other.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No.
11/254,741, filed Oct. 21, 2005, which is a divisional of
application Ser. No. 10/347,625, filed Jan. 22, 2003, now U.S. Pat.
No. 7,137,427 the contents of which are incorporated herein by
reference.
[0002] This application is based upon and claims the priority of
Japanese application no. 2002-076173, filed Mar. 19, 2002, the
contents of which are incorporated herein by reference.
[0003] This application is also related to application Ser. No.
11/254,744 filed Oct. 21, 2005, now U.S. Pat. No. 7,597,744,
application Ser. No. 11/254,712, filed Oct. 21, 2005 and
application Ser. No. 11/580,908, filed Oct. 16, 2006 the contents
of which are incorporated herein by reference
BACKGROUND OF THE INVENTION
[0004] The present invention relates to an apparatus and method for
fabricating bonded substrate (panel). More particularly, the
present invention relates to an apparatus and method for
fabricating bonded substrate for a liquid crystal display (LCD),
which is provided by bonding two substrates at a predetermined
gap.
[0005] Nowadays, there are demands for large and thin liquid
crystal display (LCD) panels capable of providing fine display on a
large display area, and apparatus which fabricates such LCD panels
have been developed. An LCD panel is fabricated by arranging two
glass substrates to face each other at an extremely narrow gap
(several micrometers) and filling a liquid crystal between the two
glass substrates. The two glass substrates are, for example, an
array substrate on which a plurality of TFTs (Thin Film
Transistors) are formed in a matrix form and a color filter
substrate on which color filters (red, green and blue), a light
shielding film, etc. are formed. The light shielding film
contributes to improving contrast and shields light toward the TFTs
to prevent generation of an optical leak current. The array
substrate is bonded to the color filter substrate by a sealing
material (adhesive) containing a thermosetting resin.
[0006] A method of fabricating an LCD panel includes a liquid
crystal sealing step of sealing a liquid crystal between two glass
substrates. The conventional liquid crystal sealing step is carried
out by the following vacuum injection method. First, the TFT-formed
array substrate is bonded to the color filter substrate (opposing
substrate) via a sealing material. The sealing material is cured.
The bonded substrates and a liquid crystal are placed in a vacuum
tank and an inlet port provided in the sealing material is dipped
in the liquid crystal. The pressure in the tank is set back to the
atmospheric pressure so that the liquid crystal is sucked from the
inlet port. Finally, the inlet port of the sealing material is
sealed.
[0007] Recently, attention has been paid to the following dropping
method instead of the vacuum injection method. First, the frame of
a sealing material is formed in such a way as to enclose the outer
periphery of the array substrate. A predetermined dose of a liquid
crystal is dropped on the surface of the array substrate within the
frame of the sealing material. Finally, the array substrate is
bonded to the color filter substrate in vacuum. The dropping method
can reduce the amount of a liquid crystal in use significantly and
can shorten the time needed for the liquid crystal sealing step,
thus resulting in a reduction in panel fabrication cost. It is
therefore expected that mass production will be improved.
[0008] A bonded-substrate fabricating apparatus which operates
according to the dropping method has the following problems.
[0009] 1. Improper Chuck Originated from the Bending of
Substrate
[0010] Normally, a substrate is held by suction by vacuum chuck or
chucking by electrostatic chuck. In the vacuum-chuck holding, a
holding plate which can hold a substrate by vacuum suction is used.
The array substrate is held by the holding plate and the frame of
the sealing material is formed on the array substrate. The adequate
amount of a liquid crystal is dropped on the surface of the array
substrate from a dispenser. Finally, the array substrate is bonded
to the color filter substrate in a vacuum atmosphere.
[0011] In the electrostatic-chuck holding, a holding plate which
has an electrode is used. A voltage is applied between the
electrode of the holding plate and a conductive film formed on a
glass substrate to generate Coulomb's force between the glass and
the electrode. The Coulomb's force electrostatically holds the
glass substrate on the holding plate.
[0012] In the vacuum-chuck holding, when the degree of vacuum in
the process chamber becomes as high as a certain level, vacuum
chuck does not work. In this respect, the substrate is
electrostatically held by electrostatic chuck before suction by
vacuum chuck stops working.
[0013] Normally, two substrates are separately held by an upper
holding plate and a lower holding plate and are bonded together.
Specifically, to prevent transfer of dust on the bonded surfaces or
contamination thereof, the outer edge areas (portions outward of
the frame of the sealing material) of the substrates are held by a
transfer robot and are moved into the process chamber. However, the
large and thin substrates are likely to curve (bend) due to their
dead loads. The holding plates cannot stably hold the bent
substrates. If the process chamber is depressurized for the purpose
of bonding the substrates, therefore, the misalignment of the
substrates or separation of the substrates from the holding plates
may occur.
[0014] In a case where the holding plate (electrostatic chuck)
electrostatically holds a bent substrate, glow discharge occurs
during depressurization of the process chamber. This case brings
about a problem such that a circuit or TFT devices formed on the
substrate are damaged, resulting in generation of defects. In
addition, as air remains between the holding plate and the
substrate, the substrate may be released from the electrostatic
chuck while depressurizing the process chamber.
[0015] 2. Improper Bonding Originated from the Bending of
Substrate
[0016] In the bonding step, two substrates are pressed while
keeping a predetermined substrate gap. The important factors in the
bonding step are to keep the two substrates parallel to each other
and to press the two substrates with a uniform load. If the
substrates are bent, however, the frame of the sealing material is
pressed unevenly in the bonding step, so that the liquid crystal
may be pushed out of the frame of the sealing material. If the
pressing pressure is uneven, the pressing pressure needed to seal
the liquid crystal increases so that the influence on the
substrates becomes greater. This makes it difficult to fabricate
stable products.
[0017] 3. Dust Oriented Improper Chuck
[0018] The holding plates that hold the two substrates separately
have chuck surfaces which are planarized at a high precision. In a
case where dust or glass pieces are adhered to the chuck surfaces,
the dust is transferred onto the substrates, causing the
misalignment of the substrates or separation of the substrates from
the holding plates. As minute dust is adhered to the holding plates
by electrostatic force, however, it is difficult to remove the dust
from the holding plates.
[0019] 4. Defects Originated from Variation in cell Thickness
[0020] It is necessary to property adjust the amount of a liquid
crystal to be sealed in an extremely narrow substrate gap (cell
thickness). The gap between the two substrates is determined by
placing spacers between the substrates or forming poles on one of
the substrates. However, the spacers and poles have a slight height
variation. This results in a change in the substrate gap, so that
the amount of the liquid crystal sealed may become too much or too
little locally. This would bring about a problem such that the cell
thickness would vary after the substrates were bonded. The
variation in cell thickness cause uneven display of the LCD
panel.
SUMMARY OF THE INVENTION
[0021] Accordingly, it is an objective of the present invention to
provide a bonded-substrate fabricating apparatus and fabricating
method which can suppress fabrication of defective bonded
substrates.
[0022] To achieve the above object, the present invention provides
an apparatus for fabricating a bonded substrate by bonding a first
substrate and a second substrate, each of the first substrate and
the second substrate having an inner surface to be bonded and an
outer surface opposite to the inner surface. The apparatus includes
a first holding plate for holding the first substrate, a second
holding plate arranged to face the first holding plate for holding
the second substrate by chucking the outer surface of the second
holding plate, and a transfer machine which transfers the first and
second substrates to the first and second holding plates
respectively and includes a holding member for holding the second
substrate horizontally by chucking the second substrate and
spouting gas onto the inner surface of the second substrate.
[0023] A further perspective of the present invention is an
apparatus for fabricating a bonded substrate by bonding a first
substrate and a second substrate, each of the first substrate and
the second substrate having an inner surface to be bonded and an
outer surface opposite to the inner surface. The apparatus includes
a first holding plate for holding the first substrate by chucking
the outer surface of the first holding plate, a second holding
plate arranged to face the first holding plate for holding the
second substrate by chucking the outer surface of the second
holding plate, and a transfer machine which transfers the first and
second substrates to the first and second holding plates
respectively and includes a holding member for holding the first
and second substrates by chucking the outer surfaces of the first
and second substrates.
[0024] A further perspective of the present invention is an
apparatus for fabricating a bonded substrate by bonding a first
substrate and a second substrate, each of the first substrate and
the second substrate having an inner surface to be bonded and an
outer surface opposite to the inner surface. The apparatus includes
a transfer machine which transfers the first and second substrates
and includes a holding member for holding the first and second
substrates by chucking the outer surfaces of the first and second
substrates, a first holding plate for holding the first substrate
transferred by the transfer machine, and a second holding plate
arranged to face the first holding plate for holding the second
substrate transferred by the transfer machine. At least one of the
first and second holding plates has a channel for retaining the
associated holding member when transfer of the associated holding
member from the transfer machine is executed.
[0025] A further perspective of the present invention is an
apparatus for fabricating a bonded substrate by bonding a first
substrate and a second substrate. The apparatus includes a transfer
machine which transfers the first and second substrates and
includes a plurality of holding members for holding the first and
second substrates horizontally, a first holding plate having a
chuck surface for chucking the first substrate transferred by the
transfer machine, and a second holding plate arranged to face the
first holding plate and having a chuck surface for chucking the
second substrate transferred by the transfer machine. At least one
of the first and second holding plates includes a chuck mechanism
which is movable up and down independently of the associated chuck
surface and sucks and holds the associated substrate. The
associated chuck surface holds the associated substrate held by the
chuck mechanism by at least one of suction and electrostatic
force.
[0026] A further perspective of the present invention is a method
of fabricating a bonded substrate by bonding two substrates in a
process chamber. The method includes sucking at least one substrate
and causing a holding plate to hold that substrate under an
atmospheric pressure, depressurizing the process chamber, stopping
suction of the at least one substrate to make a back pressure of
the at least one substrate approximately equal to a pressure in the
process chamber, and causing the at least one substrate to be
electrostatically held by the holding plate.
[0027] A further perspective of the present invention is a method
of fabricating a bonded substrate by bonding two substrates in a
process chamber. The method includes sucking at least one substrate
and causing a holding plate to hold that substrate under an
atmospheric pressure, depressurizing the process chamber, changing
a pressure in the process chamber to a value higher than the
atmospheric pressure by a predetermined pressure, and stopping
suction of the at least one substrate to electrostatically hold
that substrate.
[0028] Other aspects and advantages of the present invention will
become apparent from the following description, taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The features of the present invention that are believed to
be novel are set forth with particularity in the appended claims.
The invention, together with objects and advantages thereof, may
best be understood by reference to the following description of the
presently preferred embodiments together with the accompanying
drawings in which:
[0030] FIG. 1 is a block diagram of a bonded-substrate fabricating
apparatus according to the present invention;
[0031] FIG. 2 is a schematic diagram of the chuck mechanism of a
press machine according to a first embodiment of the present
invention;
[0032] FIG. 3 shows the chuck mechanism of the press machine in
FIG. 2;
[0033] FIGS. 4A, 4B and 4C show the chuck surface of a press
plate;
[0034] FIG. 5 is a flowchart of a bonding method;
[0035] FIG. 6 is a flowchart of another bonding method;
[0036] FIG. 7A is an enlarged view of a locally bent substrate;
[0037] FIG. 7B is an enlarged view of a substrate whose local
bending is prevented;
[0038] FIG. 8 is a diagram for explaining elimination of an
impurity by using an adhesive sheet;
[0039] FIG. 9 shows bonded substrates between which a liquid
crystal is sealed;
[0040] FIG. 10 is a block diagram of a control method for the
amount of the liquid crystal;
[0041] FIGS. 11A and 11B are flowcharts of the control method for
the amount of the liquid crystal;
[0042] FIG. 12 shows the layout of a transfer robot according to a
second embodiment of the present invention;
[0043] FIG. 13A is a schematic diagram of the transfer robot in
FIG. 12;
[0044] FIGS. 13B and 13C are enlarged views of hands of the
transfer robot in FIG. 12;
[0045] FIG. 14A is a plan view of a positioning device in FIG.
12;
[0046] FIG. 14B is a side view of the positioning device in FIG.
14A;
[0047] FIGS. 15A and 15B show a press plate according to the second
embodiment;
[0048] FIG. 16 is a schematic diagram of the chuck mechanism of a
press machine according to a third embodiment of the present
invention;
[0049] FIG. 17 is a flowchart of a bonding method which is executed
by the press machine in FIG. 16; and
[0050] FIGS. 18A and 18B show the chuck mechanism of a press plate
according to a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] A bonded-substrate fabricating apparatus 10 according to the
first embodiment of the present invention will be described
below.
[0052] The bonded-substrate fabricating apparatus 10 injects a
liquid crystal between a first substrate W1 and a second substrate
W2 and bonds the substrates W1 and W2 to fabricate a liquid crystal
display. The liquid crystal display is, for example, an active
matrix type liquid crystal display panel. The first substrate W1 is
an array substrate (TFT substrate) of glass which has an array of
TFTs, and the second substrate W2 is a color filter (CF) substrate
which has color filters and a light shielding film. The substrates
W1 and W2 are fabricated separately and are supplied to the
bonded-substrate fabricating apparatus 10.
[0053] As shown in FIG. 1, the bonded-substrate fabricating
apparatus 10 includes a control unit 11, a seal patterning system
12, a liquid crystal dropping device 13 and a bonding device 14.
The bonding device 14 comprises a press machine 15 and a curing
device 16. The control unit 11 controls the seal patterning system
12, the liquid crystal dropping device 13 and the bonding device 14
(the press machine 15 and curing device 16). Each of the components
11 to 13, 15 and 16 is used in the plural as needed.
[0054] The bonded-substrate fabricating apparatus includes first to
fifth transfer equipments 17a to 17e which transfer the first
substrate W1 and the second substrate W2. The control unit 11
controls the first to fifth transfer equipments 17a to 17e and a
transfer robot 31 (see FIG. 2) provided in the bonding device 14 to
transfer the first substrate W1 and the second substrate W2 and an
bonded substrate (integrated substrate).
[0055] The first transfer equipment 17a transfers the first
substrate W1 and the second substrate W2 to the seal patterning
system 12. The first transfer equipment 17a has an ID reader 18 for
reading identification information (substrate ID) to distinguish
the types of the first substrate W1 and the second substrate W2. As
the first substrate W1 and the second substrate W2 are supplied to
the first transfer equipment 17a, the ID reader 18 reads the
substrate ID in response to a control signal from the control unit
11 and the first transfer equipment 17a transfers the first
substrate W1 and the second substrate W2 to the seal patterning
system 12. The control unit 11 controls the dropping amount of a
liquid crystal based on the substrate ID.
[0056] The seal patterning system 12 receives the first substrate
W1 and the second substrate W2 and applies a sealing material in
predetermined positions on the top surface of one of the first
substrate W1 and the second substrate W2 (the first substrate W1 in
the first embodiment) along the periphery, thereby forming the
frame of the sealing material. The sealing material is preferably
an adhesive including a photocuring adhesive.
[0057] The second transfer equipment 17b receives the first
substrate W1 and the second substrate W2 from the seal patterning
system 12 and transfers the first substrate W1 and the second
substrate W2 as a set to the liquid crystal dropping device 13.
[0058] After the sealing material is applied, the liquid crystal
dropping device 13 drops a liquid crystal at predetermined
positions on the top surface of the first substrate W1. After the
dropping, the first substrate W1 and the second substrate W2 are
transferred to the bonding device 14 by the third transfer
equipment 17c.
[0059] The press machine 15 of the bonding device 14 is provided
with a positioning device 102 (see FIG. 12). The first substrate W1
and the second substrate W2 are transferred to the positioning
device 102. The first substrate W1 and the second substrate W2
should be bonded after being aligned accurately Accordingly the
positioning device 102 performs preliminary positioning of the
first substrate W1 and the second substrate W2 before those
substrates W1 and W2 are supplied to the press machine 15. The
positioned first substrate W1 and the second substrate W2 are
transferred to the press machine 15 by the transfer robot
[0060] The press machine 15 has a vacuum process chamber 20 (see
FIG. 3). An upper chuck, or a press plate 24a, for chucking the
second substrate (upper substrate) W2 and a lower chuck, or a table
24b, for chucking the first substrate (lower substrate) W1 are
provided in the vacuum process chamber 20. The first substrate W1
and the second substrate W2 are simultaneously transferred to the
press machine 15 and are separately held by the table 24b and the
press plate 24a.
[0061] The press machine 15 evacuates the vacuum process chamber 20
and feeds a predetermined gas to the vacuum process chamber 20 to
perform a preprocess on the substrates W1 and W2. The predetermined
gas is a substitution gas including a reactive gas, such as an
exciting gas for a plasma display panel (PDP), an inactive gas,
such as a nitrogen gas, or clean dry air. In the preprocess,
impurities and products which are adhered to the surfaces of the
substrates W1 and W2 or the surfaces of display elements is exposed
to the predetermined gas for a predetermined time. The preprocess
stably maintains the property of the bonded surfaces which cannot
be unsealed after bonding. In general, an oxide film is formed on
the surfaces of the substrates W1 and W2 so that an airborne
material in the air is adhered to the surfaces. This changes the
states of the surfaces of the substrates W1 and W2. As the degree
of a change in the surface state varies between the substrates W1
and W2, the qualities of the panels differ from one panel to
another. In this respect, changes in the surfaces of the substrates
W1 and W2 are suppressed by performing the preprocess which
suppresses the formation of a film and the adhesion of an impurity
and processes the adhered impurity.
[0062] The press machine 15 aligns the first substrate W1 with the
second substrate W2, while optically detecting an alignment mark,
in such a way that the sealing material and liquid crystal on the
first substrate W1 do not contact the bottom surface of the second
substrate W2. The press machine 15 presses the substrates W1 and W2
with a predetermined pressure in such a way as to ensure a
predetermined cell thickness. After pressing, the press machine 15
releases the vacuum process chamber 20 to set the pressure in the
vacuum process chamber 20 to the atmospheric pressure.
[0063] While monitoring the time passed from the point when the
substrates W1 and W2 were transferred to the vacuum process chamber
20, the control unit 11 controls the time from the point of
transfer to the point of bonding in such a way that the substrates
W1 and W2 are exposed to the gas supplied to the vacuum process
chamber 20 over a predetermined time. This stabilizes the bonded
surfaces of the substrates W1 and W2 and allows the bonded surfaces
to have a predetermined property.
[0064] The fourth transfer equipment 17d removes the bonded
substrate (integrated substrate W1, W2 or liquid crystal panel)
from the press machine 15 and transfers it to the curing device 16.
When the time passed from the point at which the liquid crystal
panel was pressed reaches a predetermined time, the control unit 11
drives the fourth transfer equipment 17d to supply the liquid
crystal panel to the curing device 16.
[0065] The liquid crystal that has been sealed in the liquid
crystal panel spreads between the substrates W1 and W2 by the
pressing pressure and the atmospheric pressure. It is necessary to
cure the sealing material before the liquid crystal reaches the
frame of the sealing material. Therefore, the curing device 16
irradiates light having a predetermined wavelength to the liquid
crystal panel to cure the sealing material after a predetermined
time passes after pressing. The predetermined time is determined by
acquiring the spreading time of the liquid crystal and the time
needed to release the press stress remaining on the substrates W1
and W2 beforehand through experiments.
[0066] The press stress remains on the integrated substrate W1, W2.
Because the sealing material is not cured while the substrates W1
and W2 are transferred to the fourth transfer equipment 17d, the
stress remaining on the substrates W1 and W2 is released. As the
stress hardly remains on the substrates W1 and W2 when the sealing
material is cured, the generation of a positional deviation is
reduced.
[0067] After the sealing material is cured, the fifth transfer
equipment 17e transfers the liquid crystal panel from the curing
device 16 to a device which executes the subsequent step. The
subsequent step is, for example, an inspection step for inspecting
the positional deviation between the first substrate W1 and the
second substrate W2. The inspection result is fed back to the press
machine 15 in order to correct the alignment of substrates to be
pressed next.
[0068] The press machine 15 will be discussed in detail below.
[0069] As shown in FIG. 2, the vacuum process chamber 20 is
separated into an upper container 20a and a lower container 20b
which are separable up and down.
[0070] The upper container 20a is supported by a lift mechanism
(not shown) in such a way as to be movable up and down. As shown in
FIG. 3, as the upper container 20a is moved down, the vacuum
process chamber 20 is sealed tightly. A seal 21 provided at the top
side of the lower container 20b seals between the upper container
20a and the lower container 20b.
[0071] Provided in the vacuum process chamber 20 are an upper
holding plate 22a and a lower holding plate 22b which chuck the
substrates W1 and W2, respectively. In the first embodiment, the
second substrate W2 is chucked by the upper holding plate 22a and
the first substrate W1 by the lower holding plate 22b. The upper
holding plate 22a is supported by a lift mechanism (not shown) in
such a way as to be movable up and down. The lower holding plate
22b is supported by an unillustrated drive mechanism in such a way
as to be slidable along the horizontal plane (X axis and Y axis)
and rotatable horizontally.
[0072] The upper holding plate 22a has an upper surface plate 23a,
a press plate 24a or an electrostatic chuck portion mounted to the
bottom surface of the upper surface plate 23a, and a vacuum line 25
for vacuum chucking of the second substrate W2. The vacuum line 25
includes a plurality of chuck holes opened in the bottom surface of
the press plate 24a and a horizontal line communicated with the
chuck holes and formed horizontally in the upper surface plate
23a.
[0073] The vacuum line 25 is connected to a first vacuum pump 27
via a main pipe 26a. The main pipe 26a is provided with a chuck
valve 28a. The first vacuum pump 27 and the chuck valve 28a are
connected to the control unit 11. The control unit 11 controls the
driving of the vacuum pump 27 and the opening/closing of the valve
28a. An unillustrated pressure sensor is provided in the main pipe
26a.
[0074] The main pipe 26a is connected to a pipe 26b having an
opening in the bottom surface of the upper surface plate 23a. The
pipe 26b is provided with a back pressure release valve 28b. The
opening/closing of the valve 28b is controlled by the control unit
11. As the valve 28b is opened, the pressure in the vacuum line 25
is approximately equalized to the pressure in the vacuum process
chamber 20 and the back pressure of the second substrate W2.
[0075] The main pipe 26a is connected to an atmosphere pipe 26c.
The atmosphere pipe 26c is provided with an atmosphere valve 28c.
The opening/dosing of the atmosphere valve 28c is controlled by the
control unit 11. As the atmosphere valve 28c is opened, the air is
led into the main pipe 26a via the atmosphere pipe 26c, making the
back pressure of the second substrate W2 approximately equal to the
atmospheric pressure.
[0076] The lower holding plate 22b has a lower surface plate 23b
and an electrostatic chuck portion or the table 24b mounted to the
top surface of the lower surface plate 23b. Although the lower
holding plate 22b is not provided with a suction mechanism for
vacuum chucking of the substrate W1, the lower holding plate 22b,
like the upper holding plate 22a, may be provided with a chuck
mechanism (pump 27, pipes 26a, 26b and 26c, and valves 28a, 28b and
28c).
[0077] The lower container 20b is connected via a depressurizing
pipe 26d to a second vacuum pump 29 for depressurizing the vacuum
process chamber 20. The depressurizing pipe 26d is provided with an
exhaust valve 28d. The second vacuum pump 29 and the exhaust valve
28d are controlled by the control unit 11.
[0078] A gas pipe 26e for feeding the predetermined gas to the
vacuum process chamber 20 is connected to the upper container 20a.
The gas pipe 26e is provided with a gas inlet valve 28e whose
opening/dosing action is controlled by the control unit 11.
[0079] The control unit 11 drives the first vacuum pump 27 and
opens the chuck valve 28a to evacuate the vacuum line 25 and the
main pipe 26a and vacuum-chuck the second substrate W2. The control
unit 11 electrostatically chucks the substrates W2 and W1 by
Coulomb's force generated by applying a voltage to the press plate
24a and the table 24b.
[0080] The control unit 11 switches the chuck mode for the second
substrate W2 to vacuum chuck or electrostatic chuck in accordance
with the pressure (degree of vacuum) in the vacuum process chamber
20. At the time the second substrate W2 is transferred to the
vacuum process chamber 20, for example, the control unit 11 causes
the press plate 24a to hold the second substrate W2 by vacuum chuck
(pressure differential). When the pressure in the vacuum process
chamber 20 becomes lower than the pressure in the main pipe 26a
(and the vacuum line 25), on the other hand, the control unit 11
doses the chuck valve 28a to disconnect the vacuum line 25 from the
vacuum pump 27 and causes the press plate 24a to hold the second
substrate W2 by electrostatic force.
[0081] Next, a step of carrying the substrates W1 and W2 into the
press machine 15 will be discussed by referring to FIG. 2. In the
following description, the surfaces to be bonded, i.e., the
surfaces that contact the liquid crystal (the top surface of the
first substrate W1 and the bottom surface of the second substrate
W2) are called "inner surfaces" and the opposite surfaces (the
bottom surface of the first substrate W1 and the top surface of the
second substrate W2) are called "outer surfaces".
[0082] The second substrate W2 is vacuum-chucked by the transfer
robot 31 and is carried into the press machine 15. The transfer
robot 31 has a holding member including a mechanism to chuck the
second substrate W2 or a hand 31a.
[0083] The hand 31a of the transfer robot 31 has a plurality of
chuck pads 32 for chucking the outer edge area of the inner surface
of the second substrate W2 (the portion between the frame of the
sealing material and the edge of the substrate). The chuck pads 32
are connected to an unillustrated vacuum source via a chuck line 33
formed in the hand 31a.
[0084] The hand 31a has at least one gas injection nozzle 34
provided in such a way as to face a portion inward of the outer
edge area of the inner surface of the second substrate W2. The gas
injection nozzle 34 is connected to a gas supply source (not shown)
via a gas supply line 34a formed in the hand 31a and an
unillustrated pipe, so that the gas fed from the gas supply source
is injected toward the inner surface of the second substrate W2
from the gas injection nozzle 34.
[0085] The gas injection amount (flow rate) is set in such a way as
to generate a pressure equivalent to the weight of the second
substrate W2 per unit area. The setting is carried out by first
estimating the gas injection amount based on the area, thickness
and specific gravity of the second substrate W2, the pitch between
the gas injection nozzles 34 and the distance between the nozzles
34 and the inner surface of the second substrate W2, and then
confirming the amount through experiments. As the bending of the
second substrate W2 by the dead load is prevented by the gas
injection pressure, the second substrate W2 is held by the transfer
robot 31 in an approximately horizontal state.
[0086] The gas to be spouted on the second substrate W2 is, for
example, the aforementioned reactive gas, nitrogen gas or dean dry
air. As the inner surface of the second substrate W2 is exposed to
such a gas, an impurity or product adhered to the second substrate
W2 is removed.
[0087] The transfer robot 31 causes the second substrate W2 to
approach the chuck surface of the press plate 24a while keeping the
second substrate W2 in a flat state. The press plate 24a holds the
second substrate W2 by effecting at least one of suction and
electrostatic force.
[0088] A description will now be given of the transfer of the
substrate W1 (the substrate held on the table 24b).
[0089] The substrate W1 is carried into the press machine 15 while
being chucked and held by another hand (not shown in FIG. 2) of the
transfer robot 31.
[0090] The table 24b is provided with known lift pins (not shown)
that are supported in a vertically movable manner. The substrate W1
transferred by the transfer robot 31 is received by a plurality of
lift pins elevated, and is placed on the table 24b as the lift pins
are moved downward. As electrostatic force is let to work on the
substrate W1 from the table 24b in that state, the substrate W1 is
held on the table 24b.
[0091] The press plate 24a will be discussed next.
[0092] As shown in FIG. 4B, a plurality of grooves 25a are formed
in the chuck surface of the press plate 24a at predetermined
pitches. With the second substrate W2 held by the press plate 24a,
the grooves 25a do not communicate with the vacuum line 25. The
grooves 25a extend to the end face (side surface) of the press
plate 24a along a predetermined direction (see FIGS. 4A and
4C).
[0093] Bubbles that remain between the press plate 24a and the
second substrate W2 at the time of depressurizing the vacuum
process chamber 20 are moved into the vacuum process chamber 20 via
the grooves 25a. This prevents the bubbles from remaining between
the press plate 24a and the second substrate W2 at the time of
depressurizing the vacuum process chamber 20 and thus prevents the
second substrate W2 from moving and coming off.
[0094] The grooves 25a make the contact area between the chuck
surface and the second substrate W2 smaller. When the stress stored
on the second substrate W2 is released, therefore, the position of
the second substrate W2 is prevented from being deviated.
[0095] Grooves similar to the grooves 25a of the press plate 24a
are likewise formed on chuck surface of the table 24b. Therefore,
the substrate W1 is held in a flat state and in contact with the
press plate 24a, thus preventing the movement and separation of the
substrate W1.
[0096] Referring now to FIG. 5, a method of bonding the substrates
W1 and W2 will be discussed.
[0097] In step S41, the press machine 15 is initialized. That is,
the valves 28a to 28e are all closed and the upper container 20a is
moved upward to open the vacuum process chamber 20. The first and
second vacuum pumps 27 and 29 normally driven.
[0098] In an unillustrated step, the frame of the sealing material
(adhesive) is formed on the first substrate W1 beforehand and a
liquid crystal is dropped on the surface of the first substrate W1
defined by the frame. The substrates W1 and W2 are transferred to
the initialized press machine 15 by the transfer robot 31.
Specifically, the transfer robot 31 places the second substrate W2
close to the press plate 24a while holding the substrate W2 in an
approximately horizontal state. In step S42, the press machine 15
opens the chuck valve 28a to allow the press plate 24a to hold the
second substrate W2 by vacuum chuck. In step S43, the transfer
robot 31 places the first substrate W1 onto the table 24b. In step
S43, the press machine 15 applies a predetermined voltage to the
table 24b. This causes the substrate W1 to be electrostatically
held on the table 24b.
[0099] In step S44, the press machine 15 lifts down the upper
container 20a of the vacuum process chamber 20 to close the vacuum
process chamber 20. In step S45, the press machine 15 opens the
back pressure release valve 28b. This allows the vacuum line 25 and
the main pipe 26a to communicate with the interior of the vacuum
process chamber 20 via the pipe 26b, so that the back pressure of
the second substrate W2 (the pressure in the vacuum line 25)
becomes approximately equal to the pressure in the vacuum process
chamber 20 (chamber pressure). That is, the pressure on the inner
surface side of the second substrate W2 becomes approximately equal
to the pressure on the outer surface side. This prevents the second
substrate W2 from locally bent by the pressure differential between
the top and bottom surfaces of the second substrate W2, so that the
second substrate W2 can be stably held on the press plate 24a in an
approximately flat state.
[0100] In step S46, the press machine 15 closes the chuck valve
28a. While this releases the suction force acting on the second
substrate W2, the second substrate W2 does not come off the press
plate 24a soon. This is because the outer surface of the second
substrate W2 and the chuck surface of the press plate 24a are
almost flat and moisture contained in the air is intervened between
the press plate 24a and the second substrate W2, so that adhesion
strength remains between the press plate 24a and the second
substrate W2. In step S47, the press machine 15 applies a voltage
to the press plate 24a to electrostatically chuck the second
substrate W2 within a period during which the second substrate W2
is held on the press plate 24a by the adhesion strength.
[0101] In step S48, the press machine 15 opens the exhaust valve
28d and the gas inlet valve 28e. As a result, substitution with an
inactive gas is carried out while the vacuum process chamber 20 is
depressurized by the vacuum pump 29. Because the second substrate
W2 is electrostatically chucked to the press plate 24a in an
approximately flat state during depressurization of the vacuum
process chamber 20, bubbles hardly remain on the contact surface
between the second substrate W2 and the press plate 24a. This
suppresses the generation of a glow discharge, thus preventing the
positional deviation and separation of the second substrate W2.
[0102] After a predetermined time elapses, gas substitution in the
vacuum process chamber 20 is completed. In step S49, the press
machine 15 doses the gas inlet valve 28e after the gas substitution
is completed. In step S50, the press machine 15 optically detects
an alignment mark and aligns the first and second substrates W1 and
W2 with each other in such a way that the sealing material on the
substrate W1 and the liquid crystal do not contact the bottom
surface of the substrate W2.
[0103] In step S51, the press machine 15 lifts down the upper
surface plate 23a and applies a predetermined pressure to the
substrates W1 and W2 to press the substrates W1 and W2 to a
predetermined cell thickness and bond the substrates W1 and W2
together in vacuum.
[0104] After bonding of the substrates W1 and W2, the press machine
15 stops electrostatic chuck of the press plate 24a in step S52. In
step S53, the press machine 15 closes the exhaust valve 28d to open
the atmosphere valve 28c. As a result, the pressure in the vacuum
process chamber 20 becomes the atmospheric pressure.
[0105] In step S54, the press machine 15 stops electrostatic chuck
of the table 24b and lifts the upper surface plate 23a upward. The
integrated substrate W1, W2 remains on the table 24b. The press
machine 15 moves the upper container 20a to the upper end to open
the vacuum process chamber 20.
[0106] In step S55, the transfer robot 31 removes the integrated
substrate W1, W2 from the table 24b and transfers it to the device
that executes the subsequent step. In step S56, the process returns
to step S41.
[0107] As the local bending of the second substrate W2 is corrected
and the second substrate W2 is held on the press plate 24a in an
approximately flat state by the electrostatic force according to
the bonding method in FIG. 5, the positional deviation and
separation of the second substrate W2 are prevented during
depressurization of the vacuum process chamber 20.
[0108] The bonding method in FIG. 5 may be modified as illustrated
in FIG. 6.
[0109] Steps S61 to S64 in FIG. 6 are the same as steps S41 to S44
in FIG. 5. That is, after initialization of the press machine 15,
the second substrate W2 is held on the press plate 24a, the
substrate W1 is held on the table 24b and the vacuum process
chamber 20 is dosed.
[0110] In step S65, the press machine 15 opens the gas inlet valve
28e to let the gas enter the vacuum process chamber 20. This raises
the chamber pressure to, for example, the atmospheric pressure+2
kPa (kilo pascals).
[0111] The press machine 15 stops evacuation of the vacuum process
chamber 20 by closing the chuck valve 28a (step S66) and opens the
atmosphere valve 28c to set the pressures in the main pipe 26a and
vacuum line 25 to the atmospheric pressure (step S67).
[0112] At this time, as the gas inlet valve 28e is open, the gas is
fed into the vacuum process chamber 20 so that the chamber pressure
is higher than the atmospheric pressure. Therefore, the second
substrate W2 is held on the press plate 24a by the pressure
differential between the chamber pressure and the atmospheric
pressure. The pressure differential is controlled in such a way as
to become a level which is sufficient to hold the second substrate
W2 on the press plate 24a (e.g., the chamber pressure=atmospheric
pressure+2 kPa). Accordingly, the local bending of the second
substrate W2 is suppressed so that the second substrate W2 is
stably fixed on the press plate 24a in an approximately fiat
state.
[0113] The press machine 15 applies a voltage to the press plate
24a to allow the press plate 24a to electrostatically hold the
second substrate W2 (step S68) and closes the atmosphere valve 28c
and the gas inlet valve 28e to open the back pressure release valve
28b (step S69). Opening the back pressure release valve 28b
eliminates the pressure differential between the top and bottom
surfaces of the second substrate W2, thus preventing the occurrence
of local bending of the second substrate W2 and the positional
deviation and separation of the second substrate W2.
[0114] In step S70, the press machine 15 opens the exhaust valve
28d and the gas inlet valve 28e. Consequently, the vacuum process
chamber 20 is evacuated by the vacuum pump 29 and gas substitution
is carried out. At this time, the second substrate W2 is
electrostatically chucked to the press plate 24a in an
approximately flat state and bubbles hardly remain on the contact
surface of the second substrate W2 and the press plate 24a. This
suppresses the generation of a glow discharge, thus preventing the
positional deviation and separation of the second substrate W2.
[0115] In step S71, the press machine 15 doses the gas inlet valve
28e after gas substitution in the vacuum process chamber 20 is
completed. Steps S72 to S78 are the same as steps S50 to S55 in
FIG. 5.
[0116] According to the bonding method in FIG. 6, bending of the
second substrate W2 is prevented and positional deviation and
separation of the second substrate W2 are prevented in a period
during which the vacuum process chamber 20 is evacuated. While the
vacuum chuck of the second substrate W2 is stopped and the second
substrate W2 is electrostatically held, the second substrate W2 is
pressed on the press plate 24a and stably held by the pressure
differential originated from the supply of the gas. Further, the
method allows the gas to efficiently remove impurities in the
vacuum process chamber 20 and on the inner surface of the second
substrate W2.
[0117] A description will now be given of local bending of the
second substrate W2.
[0118] When the press plate 24a holds the second substrate W2 by
suction, local bending occurs as shown in FIG. 7A due to the
pressure differential between the top and bottom surfaces of the
second substrate W2. The thinner the second substrate W2 is, the
more prominent the bending originated from the pressure
differential becomes.
[0119] To prevent local bending, it is preferable to provide a
porous member 80 of porous ceramics or the like which has, for
example, a permeability in the grooves 25a. Providing the porous
member 80 in the grooves 25a improves the rigidity of the chuck
surface and makes the chuck surface flat, thus preventing local
bending of the second substrate W2. In the bonding step of the
substrates W1 and W2, the effect of preventing positional deviation
and separation of the second substrate W2 from the press plate 24a
due to the bending of the second substrate W2 is further
improved.
[0120] To prevent a waste from being stored inside the porous
member 80 and contaminating the second substrate W2, it is
desirable to eliminate dust or the like by regular counterflow of a
gas (inactive gas).
[0121] A description will now be given of a method of removing
impurities from the press plate 24a and table 24b.
[0122] Impurities, such as dust or glass pieces of the substrates
W1 and W2, are apt to be adhered to the press plate 24a and the
table 24b. The impurities may damage the chuck surfaces of the
press plate 24a and table 24b or may cause positional deviation and
separation of the substrates W1 and W2 at the time of chucking the
substrates W1 and W2. It is therefore necessary to eliminate the
impurities adhered to the press plate 24a and table 24b.
[0123] FIG. 8 shows an adhesive sheet 81 which comprises a tape
base 82 and an adhesive layer 83 formed by applying an adhesive to
both sides of the tape base 82. Impurities 84, such as dust or
glass pieces, adhered to the press plate 24a and table 24b are
removed by using the adhesive sheet 81. Specifically, first, an
impurity eliminating device (sheet feeder) 800 feeds the adhesive
sheet 81 into the press machine 15 and adheres the adhesive sheet
81 to the chuck surface of the table 24b.
[0124] The press machine 15 tightly closes the vacuum process
chamber 20 and opens the exhaust valve 28d to evacuate the vacuum
process chamber 20. After the vacuum process chamber 20 is
depressurized to a predetermined pressure (almost vacuum), the
upper surface plate 23a is lifted down to the position where the
press plate 24a comes in close contact with the adhesive sheet 81.
The exhaust valve 28d is closed and the gas inlet valve 28e is
opened to set the chamber pressure nearly to the atmospheric
pressure. With the vacuum process chamber 20 opened, the upper
surface plate 23a is lifted upward so that the adhesive sheet 81 on
the table 24b is separated by the transfer mechanism.
[0125] According to the impurity removing method, the adhesive
sheet 81 is adhered to the press plate 24a and table 24b evenly and
firmly in vacuum and the impurities 84, such as dust or glass
pieces, find their way into the adhesive layer 83. Therefore, even
minute dust is effectively removed from the chuck surface.
[0126] The elasticity of the tape base 82 allows dust or the like
to be removed from the chuck surfaces of the press plate 24a and
table 24b without damaging the chuck surfaces.
[0127] To enhance the impurity removing effect, it is preferable to
execute the method with the vacuum process chamber 20
depressurized. The method may however be executed in the
atmospheric pressure in which case, the time to depressurize the
vacuum process chamber 20 is shortened and a certain degree of an
impurity removing effect is acquired.
[0128] Instead of sandwiching the adhesive sheet 81 between the
press plate 24a and table 24b, the adhesive sheet 81 may be adhered
to each of the press plate 24a and table 24b and be separated
therefrom later. In case where the adhesive layer 83 is applied
only to one side of the tape base 82, the impurities adhered to the
press plate 24a and table 24b may be removed alternately in an
arbitrary order or the adhesive sheet 81 may be adhered to the
press plate 24a and table 24b individually.
[0129] In a case where the press plate 24a and table 24b are
detachable from the press machine 15, impurities may be removed by
the adhesive sheet 81 outside the vacuum process chamber 20
(outside the bonded-substrate fabricating apparatus 10).
[0130] The amount of a liquid crystal to be sealed between the
substrates W1 and W2 will be discussed below.
[0131] Because two substrates W1 and W2 should be bonded together
with an extremely small gap (cell thickness), it is necessary to
adjust the amount of a liquid crystal to be sealed to the adequate
amount.
[0132] As shown in FIG. 9, a plurality of spacers or poles 85 for
restricting the gap (cell thickness) between the substrates W1 and
W2 to a predetermined value are formed on one substrate (the array
substrate W1 on which the liquid crystal is to be dropped in the
first embodiment). After a liquid crystal LC is dropped within the
frame of a sealing material 86, the substrates W1 and W2 are bonded
together.
[0133] The height of the poles 85 (pole height) may vary from a
predetermined value. The variation in pole height causes the gap
between the substrates W1 and W2 to change from its predetermined
value. It is therefore necessary to adjust the dropping amount of
the liquid crystal LC in accordance with the pole height before
bonding the substrates W1 and W2. The adjustment of the dropping
amount of the liquid crystal LC will be described below referring
to FIG. 10.
[0134] FIG. 10 shows the bonded-substrate fabricating apparatus 10
which is equipped with a plurality of seal patterning systems 12, a
plurality of liquid crystal dropping devices 13, a plurality of
press machines 15 and a plurality of curing devices 16. The ID
reader 18 is provided in the first transfer equipment 17a.
[0135] A pole height measuring unit 87 is connected to the
bonded-substrate fabricating apparatus 10 via a network. The pole
height measuring unit 87 measures the height of the poles 85 formed
on one of the substrates W1 and W2 (e.g., the array substrate W1).
The measuring unit 87 has an ID reader 88 for reading a substrate
ID to distinguish the types of the substrates W1 and W2.
[0136] In step S91a in FIG. 11A, the ID reader 88 reads the
substrate ID of the substrate W1. In step S92a, the pole height
measuring unit 87 measures the height of the poles 85 formed on the
substrate W1. In step S93a, the pole height measuring unit 87
stores the measuring result or pole height information in a first
memory device 87a in the pole height measuring unit 87 in
association with the substrate ID. The pole height measuring unit
87 performs steps S91 a to S93a in advance before the substrate W1
is transferred to the bonded-substrate fabricating apparatus
10.
[0137] As shown in FIG. 11B, when the first transfer equipment 17a
receives the substrates W1 and W2, the control unit 11 (see FIG. 1)
causes the ID reader 18 to read the substrate ID of the substrate
W1 (step S91b). Specifically, the first transfer equipment 17a
reads the substrate ID of the substrate W1 having the poles 85 and
transfers the substrates W1 and W2 to the associated seal
patterning system 12 in accordance with an instruction from the
control unit 11.
[0138] The control unit 11 reads the pole height information
associated with the substrate ID of the substrate W1 from the first
memory device 87a and stores the pole height information into a
second memory device 87b in the control unit 11 (step S92b). Based
on the pole height information, the control unit 11 determines the
liquid crystal dropping device 13 that drops the liquid crystal LC
(step S93b). In a case where the bonded-substrate fabricating
apparatus 10 is provided with only one type of liquid crystal
dropping device 13, step S93b is omitted and the second transfer
equipment 17b transfers the substrates W1 and W2 from the seal
patterning system 12 to that liquid crystal dropping device 13.
[0139] In step S94b, the control unit 11 computes the dropping
amount of the liquid crystal LC. Specifically, a correction value
for correcting an error in the dropping amount of the liquid
crystal LC among a plurality of liquid crystal dropping devices 13
is set beforehand for each liquid crystal dropping device 13. The
control unit 11 computes the proper dropping amount of the liquid
crystal LC based on the dropping amount of the liquid crystal LC
for the pole height information acquired beforehand through
experiments and the correction value for the dropping amount.
[0140] The control unit 11 instructs the proper dropping amount of
the liquid crystal LC to the liquid crystal dropping device 13
(step S95b) and the liquid crystal dropping device 13 drops the
proper dropping amount of the liquid crystal LC onto the substrate
W1 (step S96b).
[0141] According to the control method in FIGS. 11A and 11B, the
dropping amount of the liquid crystal LC is corrected in accordance
with the pole height of the poles 85 formed on the substrate W1 and
which liquid crystal dropping device 13 was used. This reduces the
rate of defects of the integrated substrates W1, W2, thus reducing
the wasteful amount of the liquid crystal LC in use.
[0142] The serial number information of the pole height measuring
unit 87 that has measured the pole height may be added to the
substrate ID and the pole height information and stored in the
first memory device 87a.
[0143] In some cases, the bonded-substrate fabricating apparatus 10
may have a plurality of pole height measuring units 87 for the
purpose of mass production and stable operation or the like. In
such a case, there is a possibility that an error occurs in the
measured value of the pole height due to a variation in the pole
height measuring units 87. It is therefore important to grasp which
pole height measuring unit 87 has been used to measure the pole
height information of the substrate W1. Adding the serial number
information of the pole height measuring unit 87 to the substrate
ID and the pole height information ensures computation of the
proper dropping amount of the liquid crystal LC in consideration of
variations in the pole height measuring units 87 and the liquid
crystal dropping devices 13.
[0144] A lot number may be added to the substrate ID and the pole
height information and stored in the first memory device 87a. The
lot number is a number to be given to a predetermined number of
substrates W1 which are processed in a predetermined process unit
period. Since the pole height information of the substrates W1 that
have the same lot number can be acquired at a time according to the
method, it is possible to calculate the dropping amount of the
liquid crystal on the substrates W1 having the same lot number
beforehand. This can eliminate the trouble of calculating the
dropping amount of the liquid crystal for each substrate, so that
the response time of the control unit 11 can be shortened and the
productivity can be improved.
[0145] The First Embodiment has the Following Advantages.
[0146] (1) While a gas is injected toward the inner surface of the
second substrate W2, the second substrate W2 is transferred to the
press machine 15 and held on the press plate 24a by the transfer
robot 31 which chucks and holds the outer edge area of the inner
surface or a transfer robot 31 that chucks and holds the outer edge
area of the outer surface of the second substrate W2. Therefore,
even the second substrate W2 which is likely to be bent due to the
dead bad is held on the press plate 24a while being kept
horizontally. As the second substrate W2 is stably held on the
press plate 24a, the positional deviation of the second substrate
W2 on the press plate 24a, the separation of the second substrate
W2 from the press plate 24a and the generation of a glow discharge
at the time of performing electrostatic chuck are prevented. This
results in improvements on the production yield and productivity of
large and thin LCD panels.
[0147] (2) As the back pressure of the second substrate W2 is kept
approximately equal to the pressure in the vacuum process chamber
20, local bending of the second substrate W2 originated from the
pressure differential between the top and bottom surfaces of the
second substrate W2 is prevented. Further, the movement or
separation of the second substrate W2 is prevented due to bubbles
remaining on the contact surface between the chuck surface of the
press plate 24a and the second substrate W2, during
depressurization of the vacuum process chamber 20.
[0148] (3) A plurality of grooves 25a are formed at predetermined
pitches in the chuck surface of the press plate 24a with the end
face (side) of the press plate 24a being cut away. Accordingly, the
movement or separation of the second substrate W2, originated from
even if bubbles remain on the contact surface between the press
plate 24a and the second substrate W2, the bubbles become easier to
move into the vacuum process chamber 20 during depressurization of
the vacuum process chamber 20. Therefore, the movement or
separation of the second substrate W2 or the like originated from
the influence (expansion or the like) of the bubbles is prevented
too.
[0149] (4) The porous member 80 having a permeability is provided
in the grooves 25a of the press plate 24a. This structure surely
prevents the local bending of the second substrate W2 originated
from the pressure differential between the top and bottom surfaces
of the second substrate W2 at the time of sucking the second
substrate W2. This advantage can further enhance the advantage
(2).
[0150] (5) Impurities, such as dust or glass pieces, adhered to the
press plate 24a and the table 24b are removed by the adhesive sheet
81. As the adhesive sheet 81 is adhered to the press plate 24a and
table 24b evenly and firmly in vacuum in the present embodiment,
those impurities are effectively removed.
[0151] (6) The pole height measuring unit 87 measures the height of
the poles 85 of the substrate W1. The optimal dropping amount of
the liquid crystal LC which is corrected in accordance with the
pole height information and the liquid crystal dropping device 13
that drops the liquid crystal LC is dropped on the substrate W1.
This can reduce the rate of defects of the integrated substrates
W1, W2 and the wasteful amount of the liquid crystal LC in use. By
adding the serial number information of the pole height measuring
unit 87 that has measured the pole height and a lot number to the
pole height information, the dropping amount of the liquid crystal
LC can be corrected more accurately and more efficiently. As the
amount of the liquid crystal LC to be sealed is optimized, the
yield of the liquid crystal panels is improved, thus making it
possible to cope with products with a narrow substrate gap.
[0152] The following will discuss a transfer robot 101 and a method
of fabricating a bonded substrate according to the second
embodiment of the invention. As like or same reference numerals are
given to those components which are the same as the corresponding
components of the first embodiment that has been described earlier
with reference to FIG. 2, their detailed descriptions will be
partly omitted.
[0153] FIG. 12 shows the layout of the bonding device 14 (the
curing device 16 not illustrated). The transfer robot 101 is
provided between the positioning device 102 which carries out
positioning of the first substrate W1 and the second substrate W2,
the press machine 15 which carries out a bonding work and a
disposing position 103 and is swingable to positions that
respectively face the positioning device 102, the press machine 15
and the disposing position 103.
[0154] In the first bonding step for the substrates W1 and W2, it
is necessary to transfer three types of parts (first substrate W1,
second substrate W2 and integrated substrate W1, W2). To improve
the fabrication efficiency of a bonded substrate, an improvement of
the transfer efficiency for those three types of parts is
demanded.
[0155] The transfer robot 101 has a rotary portion 104, a first
transfer arm 105 and a second transfer arm 106. As shown in FIG.
13A, the rotary portion 104 is provided in such a way as to be
rotatable approximately 360 degrees about a body 104a and movable
up and down along the axis (Z axis) of the body 104a. The first and
second transfer arms 105 and 106 are individually extensible and
contractible horizontally (directions of the X axis and Y axis)
with respect to the rotary portion 104 and are slightly movable up
and down in the Z-axial direction.
[0156] Therefore, the transfer robot 101 swings to each of the
positions of the positioning device 102, the press machine 15 and
the disposing position 103 and extends or contracts at least one of
the first and second transfer arms 105 and 106 to transfer the
substrates W1 and W2.
[0157] As shown in FIG. 13B, holding members or first and second
hands 105a and 105b are provided at the distal end of the first
transfer arm 105. A plurality of chuck pads 107 are provided on the
bottom surface of the first hand 105a. The chuck pads 107 hold the
second substrate W2. Specifically, the chuck pads 107 suck the
outer surface of the second substrate W2 by means of an
unillustrated vacuum source. A plurality of chuck pads 108 are
provided on the top surface of the second hand 105b. The plurality
of chuck pads 108 suck the outer surface of the first substrate
W1.
[0158] As shown in FIG. 13C, a holding member or a third hand 106a
is provided at the distal end of the second transfer arm 106. A
plurality of chuck pads 109 are provided on the top surface of the
third hand 106a. The chuck pads 109 suck the integrated substrate
W1, W2.
[0159] The transfer robot 101 first swings to the position facing
the positioning device 102, holds one of the positioned substrates
(second substrate W2) with the first hand 105a and takes out the
substrate W2 from the positioning device 102. Next, the transfer
robot 101 holds the other positioned substrate (first substrate W1)
with the second hand 105b and takes out the substrate W1 from the
positioning device 102. Those manipulations are carried out while
the press machine 15 is bonding the previous substrates W1 and
W2.
[0160] Next, the transfer robot 101 swings to the position facing
the press machine 15. When the press machine 15 completes bonding
the previous substrates W1 and W2, the transfer robot 101 holds the
integrated substrate W1, W2 with the third hand 106a and takes out
the integrated substrate W1, W2 from the press machine 15.
Subsequently, the transfer robot 101 transfers the substrates W2
and W1, respectively held by the first and second hands 105a and
105b, to the press machine 15.
[0161] Thereafter, the transfer robot 101 swings to the position
facing the disposing position 103 and disposes the integrated
substrate W1, W2 held by the third hand 106a in the disposing
position 103.
[0162] As apparent from the above, the transfer robot 101 performs
a swing operation from the positioning device 102 to the disposing
position 103, a single extensible and contractible operation of the
first transfer arm 105 to transfer a set of substrates W1 and W2 to
the press machine 15 and a single extensible and contractible
operation of the second transfer arm 106 to transfer the integrated
substrate W1, W2 from the press machine 15. That is, the transfer
robot 101 can transfer a set of substrates W1 and W2 by a single
swing operation and two extensible and contractible operations.
[0163] By way of contrast, the first transfer arm of the
conventional transfer robot has the first hand (singular) and the
second transfer arm has the second hand (singular). Therefore, the
conventional transfer robot needs to perform two swing operations
from the positioning device 102 and a total of three extensible and
contractible operations of the first and second transfer arms for
carrying the substrates W1 and W2 into/out of the press machine 15
at the time of executing a single transfer of the substrates W1 and
W2 to the press machine 15. Because the use of the transfer robot
101 in FIG. 13A reduces the number of operations, the transfer time
of substrates is shortened, which can thus shorten the time in
which the operation of the press machine 15 is stopped. The
transfer robot 101 therefore ensures an efficient transfer
work.
[0164] In a case where the second substrate W2 is carried into the
press machine 15 by the first hand 105a (to be held on the press
plate 24a), it is preferable to use a press plate 111 shown in
FIGS. 15A and 15B. The press plate 111 has a channel 111a formed
along the moving passage of the first hand 105a. The first hand
105a moves under the press plate 111 while holding the outer
surface of the second substrate W2 and moves upward to a position
where the second substrate W2 comes close to the chuck surface of
the press plate 111 as shown in FIGS. 15A and 15B. As the first
hand 105a is retained in the channel 111a at that time, it does not
interfere with the press plate 111. In this state, the press plate
111 chucks and holds the second substrate W2 by at least one of
suction and electrostatic force. After suction of the second
substrate W2 is stopped, the first hand 105a moves upward to be
away from the second substrate W2. Finally, the first transfer arm
105 is pulled back.
[0165] Because the first hand 105a sucks and holds the outer
surface of the second substrate W2, weight-originated bending of
the second substrate W2 is prevented even if the second substrate
W2 is large and thin. The second substrate W2 is therefore chucked
to the chuck surface of the press plate 111 in an approximately
flat state.
[0166] At least one of the first and second transfer arms 105 and
106 of the transfer robot 101 is provided with two hands.
Accordingly, the second transfer arm 106 may have two hands.
[0167] The first hand 105a may be replaced with the hand 31a in
FIG. 2. In this case, for example, the hand 31a which transfers the
second substrate W2 is provided at the first transfer arm 105 and
the second hand 105b which transfers the substrate W1 and the third
hand 106a which transfers the integrated substrate W1, W2 are
provided at the second transfer arm 106.
[0168] The Positioning Device 102 will be Discussed Below
[0169] In case of bonding the substrates W1 and W2, the substrates
W1 and W2 should be aligned at a high precision (within an error of
several micrometers). In this respect, alignment marks of a size of
microns are formed on the substrates W1 and W2. Normally a lens
with a long focal distance is needed to simultaneously catch the
alignment marks of the two apart substrates W1 and W2. Such a lens
is however complex in structure and expensive. It is therefore
preferable that the positioning device 102 should perform
preliminary positioning of the substrates W1 and W2 before the
press machine 15 would bond the substrates W1 and W2.
[0170] As shown in FIG. 14, the positioning device 102 has a base
plate 121, positioning pins 122 attached to the base plate 121,
support plates 123 for supporting the second substrate W2, a
support pin 124 which supports the substrate W1, a chuck mechanism
125, a positioning mechanism 126 and a linear actuator 127.
[0171] The support plates 123 are movable to a position for
supporting the outer edge area of the inner surface of the second
substrate W2 and a position apart from the second substrate W2
along linear guides 121a provided on the base plate 121. The
support pin 124 is movable up and down. The positioning mechanism
126 is movable as indicated by arrows in FIG. 14A. The driving of
the support plates 123, the support pin 124 and the positioning
mechanism 126 is controlled by a drive source, such as
unillustrated cylinders or the like.
[0172] The chuck mechanism 125 is supported by the linear actuator
127 in such a way as to be movable up and down with respect to the
base plate 121. The chuck mechanism 125 has an upper plate 128a, a
lower plate 128b, a bearing 129 which supports the upper plate 128a
in such a way that the upper plate 128a is movable horizontally in
the directions of the X axis and Y axis with respect to the lower
plate 128b, and a spring 130 which urges the upper plate 128a to a
reference position (the position shown in FIG. 14A) of the lower
plate 128b. A plurality of chuck portions 131 are provided on the
bottom surface of the upper plate 128a in parallel at predetermined
pitches. Each chuck portion 131 has a chuck pad 132.
[0173] The positioning of the substrates W1 and W2 will be
discussed below.
[0174] First, the second substrate W2 is positioned as follows. The
chuck mechanism 125 is moved upward and the support pin 124 is
moved downward. The third transfer equipment 17c (see FIG. 1)
transfers the second substrate W2 to the positioning device 102
from the liquid crystal dropping device 13. As a result, the second
substrate W2 is supported on the support plates 123 as indicated by
a two-dot chain line in FIG. 14A.
[0175] As the second substrate W2 is placed on the support plates
123, the chuck mechanism 125 is moved downward and sucks and holds
the top surface (outer surface) of the second substrate W2 by means
of the chuck pads 132. The chuck mechanism 125 is moved upward
together with the second substrate W2 and the support plates 123
are moved to positions where the support plates 123 do not
interfere with the second substrate W2. The second substrate W2 is
suspended from the chuck mechanism 125.
[0176] Next, the positioning mechanism 126 moves forward to move
the second substrate W2 horizontally toward the positioning pins
122 provided diagonal to the positioning mechanism 126. The
positioning mechanism 126 pushes the edge (the corner or the side
near the corner) of the second substrate W2 until a predetermined
position or until the corner of the second substrate W2 abuts on
the positioning pins 122. At that time, the chuck mechanism 125
which is holding the second substrate W2 moves too. The movements
of the chuck mechanism 125 and the second substrate W2 are carried
out smoothly by the bearing 129.
[0177] The transfer robot 101 extends the first transfer arm 105.
The first hand 105a sucks and holds the top surface of the second
substrate W2 placed in a predetermined position. When the transfer
robot 101 holds the second substrate W2, the chuck mechanism 125
stops sucking the second substrate W2. After chucking of the second
substrate W2 is stopped, the chuck mechanism 125 is moved upward by
the linear actuator 127 and is returned to the reference position
by the urging force of the spring 130.
[0178] Next, the third transfer equipment 17c (see FIG. 1)
transfers the substrate W1 to the positioning device 102 from the
liquid crystal dropping device 13. Before the transfer, the chuck
mechanism 125 should have been moved upward and the support plates
123 should have been moved to positions where the support plates
123 do not interfere with the substrate W1. The substrate W1 is
supported by the lifted-up support pin 124. The positioning
mechanism 126 pushes the edge of the substrate W1 to move the
substrate W1 to a predetermined position. The transfer robot 101
extends the first transfer arm 105 and sucks and holds the bottom
surface of the substrate W1 by means of the second hand 105b.
[0179] According to the positioning device 102, the second
substrate W2 is chucked by the chuck mechanism 125 having the chuck
pads 132, so that bending of the second substrate W2 due to its
dead bad is suppressed and the second substrate W2 is positioned in
an approximately flat state by the positioning mechanism 126.
[0180] By way of contrast, the conventional positioning device does
not have the chuck mechanism 125. In a case where the second
substrate W2 is large or thin, therefore, the second substrate W2
bends. Thus, when the bent substrate is positioned, the bending of
the second substrate W2 becomes greater, so that accurate
positioning cannot be ensured, disadvantageously.
[0181] According to the second embodiment, the second substrate W2
is positioned in an approximately flat state, thus improving the
precision of positioning the second substrate W2. This results in
an improvement on the alignment precision in the press machine
15.
[0182] The second embodiment has the following advantages in
addition to the advantages (1) to (6).
[0183] (7) The transfer robot 101 includes the first transfer arm
105 having the first and second hands 105a and 105b and the second
transfer arm 106 having the third hand 106a. As the transfer robot
101 can carry two substrates W1 and W2 into the press machine 15 at
a time, the number of the swing operations and extensible and
contractible operations of the transfer robot 101 is reduced and
the transfer time is shortened. This makes it possible to shorten
the transfer-oriented idling time of the press machine 15, thus
improving the productivity of the bonded substrate.
[0184] (8) The first and second hands 105a and 105b suck and hold
the outer surfaces of the substrates W2 and W1. This allows even
large and thin substrates W2 and W1 to be stably held in an
approximately flat state without being bent. Because the first and
second hands 105a and 105b can be attached to the first transfer
arm 105 at relatively narrow pitches, enlargement of the press
machine 15 can be avoided.
[0185] (9) Because the positioning device 102 positions the second
substrate W2 held on the chuck mechanism 125 in an approximately
flat state, the positioning precision is improved. This results in
an improved positioning precision in the press machine 15. As the
positioning device 102 can position the second substrate W2
quickly, the alignment time in the press machine 15 is shortened,
thus shortening the fabrication time for bonded substrates.
[0186] (10) As the first and second hands 105a and 105b do not
contact the inner surfaces of the substrates W2 and W1, changes in
the properties of the inner surfaces of the substrates W2 and W1
are prevented.
[0187] A description will now be given of a press machine 141 and a
bonding method according to the third embodiment of the invention.
As like or same reference numerals are given to those components
which are the same as the corresponding components of the first
embodiment that has been described earlier with reference to FIG.
2, some of their detailed descriptions will not be repeated.
[0188] As shown in FIG. 16, the press machine 141 has a first
exhaust valve 28d for evacuating the vacuum process chamber 20, a
bypass pipe 26f which connects the main pipe 26a to the
depressurizing pipe 26d, and a second exhaust valve 28f which is
provided in the bypass pipe 26f and evacuates the main pipe 26a and
vacuum line 25. The opening/closing action of the second exhaust
valve 28f is controlled by the unillustrated control unit.
[0189] In a case where the press machine 141 is used, steps S151 to
S153 in FIG. 17 are executed in place of step S48 in FIG. 5 and
step S70 in FIG. 6. That is, in step S151, the press machine 141
opens the first and second exhaust valves 28d and 28f and opens the
gas inlet valve 28e and starts gas substitution in the vacuum
process chamber 20.
[0190] At the beginning of the depressurization of the vacuum
process chamber 20, the exhaust valves 28d and 28f are opened
relatively narrowly so that a variation in pressure does not become
too large. A variation in pressure may be adjusted by increasing
the rotational speed of the vacuum pump 29 gradually.
[0191] In step S152, the press machine 141 gradually increases the
degrees of opening of the first and second exhaust valves 28d and
28f in such a way that the back pressure of the second substrate W2
becomes approximately equal to or lower than the chamber pressure.
When the chamber pressure and the back pressure of the second
substrate W2 reach predetermined values, the press machine 141
fully opens both exhaust valves 28d and 28f (step S153).
[0192] The subsequent steps are the same as those of the first
embodiment. That is, after the gas substitution in the vacuum
process chamber 20 is completed, the gas inlet valve 28e is closed
and the substrates W1 and W2 are aligned and pressed.
[0193] According to the third embodiment, the degrees of opening of
the exhaust valves 28d and 28f (the exhaust speed and
depressurizing speed) are adjusted, so that even when the
conductance from the chuck surface of the press plate 24a to the
vacuum process chamber 20 (the degrees of vacuum in the vacuum line
25 and the pipes 26a and 26b) is relatively small, it is possible
to adjust the back pressure of the second substrate W2 to be
approximately equal to or lower than the chamber pressure. In other
words, even when the passage from the chuck surface of the press
plate 24a to the vacuum process chamber 20 is narrow and
depressurization is difficult, advantages similar to those of the
first embodiment can be acquired. Note that the third embodiment
brings about similar advantages even without the pipe 26b and the
back pressure release valve 28b.
[0194] A fabrication apparatus and method for bonded substrates
according to the fourth embodiment of the invention will be
discussed below.
[0195] FIG. 18A shows an upper holding plate 161 according to the
fourth embodiment. The upper holding plate 161 includes an upper
surface plate 162 and a press plate 163. Through passages 164 are
formed in such a way as to extend from the chuck surface of the
press plate 163 to the top surface of the upper surface plate
162.
[0196] The upper holding plate 161 includes a chuck mechanism 165
which is supported by an unillustrated drive mechanism in such a
way as to be movable up and down. The chuck mechanism 165 comprises
a top plate 165a, chuck portions 165b supported on the top plate
165a and chuck pads 165c provided at the distal ends (lower ends)
of the individual chuck portions 165b. The chuck portions 165b are
respectively inserted into the through passages 164. The chuck pads
165c are connected to a vacuum source via an unillustrated passage.
The suction force from the vacuum source allows the outer surface
of the second substrate W2 to be sucked to the chuck portions
165b.
[0197] As shown in FIG. 18A, the chuck mechanism 165 is lifted
downward in such a way that the chuck pads 165c are placed below
the chuck surface of the press plate 163. The second substrate W2
held by the transfer robot 31 (FIG. 2) is chucked to the chuck pads
165c.
[0198] The chuck mechanism 165 is lifted upward to a position where
the second substrate W2 comes close to the chuck surface of the
press plate 163. As the suction force or electrostatic force is
allowed to act on the second substrate W2 in that state, the second
substrate W2 is sucked to the press plate 163 and the chucking work
of the chuck mechanism 165 is stopped. As a result, the second
substrate W2 is held on the press plate 163 (FIG. 18B).
[0199] According to the fourth embodiment, the second substrate W2
is held on the press plate 163 while being sucked by the chuck
portions 165b. Therefore, the second substrate W2 even bent greatly
is held on the press plate 163 in an approximately flat state, thus
preventing positional deviation and separation of the second
substrate W2.
[0200] As shown in FIG. 18B, the pressure in the vacuum process
chamber 20 acts on the top surface of the second substrate W2 via
the through passages 164. During depressurization of the vacuum
process chamber 20, therefore, the back pressure of the second
substrate W2 does not become higher than the chamber pressure, thus
preventing separation of the second substrate W2.
[0201] The chuck portions 165b may be moved up and down
individually and independently. In this case, a substrate which is
bent greatly is chucked smoothly.
[0202] It should be apparent to those skilled in the art that the
present invention may be embodied in many other specific forms
without departing from the spirit or scope of the invention.
[0203] Although the transfer of the substrate W2 has been described
in the description of the first embodiment, the lower substrate W1
may likewise be transferred while a gas is injected toward the
bottom surface of the lower substrate W1.
[0204] In the bonding method in FIG. 5, step S44 (tight closing of
the vacuum process chamber 20) may be executed after step S47.
[0205] The transfer robot 31 may spout a gas other than an inactive
gas toward the bottom surface of the second substrate W2.
[0206] A filter may be provided upstream of the gas injection
nozzle 34 so that dust does not stick to the second substrate
W2.
[0207] The transfer robot 31 may be modified in such a way as to
have a mechanism which chucks the top surface of the second
substrate W2 while spouting a gas to the bottom surface of the
second substrate W2 in a case where the second substrate W2 is
large.
[0208] The first memory device 87a and the second memory device 87b
which store the substrate ID and pole height information may be
provided in a server connected to the bonded-substrate fabricating
apparatus 10 via a network.
[0209] The parts that are respectively held by the first to third
hands 105a, 105b and 106a are not limited to those types which have
been discussed in the foregoing descriptions of the embodiments. To
describe in detail, the substrate W1 may be held and transferred by
the third hand 106a, and the integrated substrate W1, W2 may be
held and carried out of the press machine 15 by the second hand
105b. In case where the substrates W2 and W1 are respectively held
by the first and second hands 105a and 105b of the first transfer
arm 105 as described in the descriptions of the embodiments, dust
is prevented from falling on the surface of the substrate W1.
[0210] Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive and the invention is
not to be limited to the details given herein, but may be modified
within the scope and equivalence of the appended claims.
* * * * *