U.S. patent application number 09/851428 was filed with the patent office on 2002-01-24 for method of manufacturing flat-panel display device.
Invention is credited to Hasegawa, Tatsuya, Horita, Takao, Yomogihara, Yoshikazu.
Application Number | 20020008832 09/851428 |
Document ID | / |
Family ID | 26591614 |
Filed Date | 2002-01-24 |
United States Patent
Application |
20020008832 |
Kind Code |
A1 |
Hasegawa, Tatsuya ; et
al. |
January 24, 2002 |
Method of manufacturing flat-panel display device
Abstract
A method of manufacturing a flat-panel display device including
a series of steps for pasting a light-control tape onto a display
panel proper, the series of steps for pasting comprising: a step of
determining a start position for pasting; a step of taking out the
start end of the light-control tape by drawing to peel a release
sheet covering a downward-facing adhesive face of the light-control
tape; a step of positioning the start end of the light-control tape
to the start position; a step of pressing the start end of the
light-control tape onto the start position by a rotatable press
roller; a step of continuously pasting the light-control tape onto
the display panel proper by moving the display panel proper; a step
of cutting the light-control tape when pasted by a predetermined
length; and a step of completing of pasting a cut piece of the
light-control tape.
Inventors: |
Hasegawa, Tatsuya; (Tokyo,
JP) ; Horita, Takao; (Tokyo, JP) ; Yomogihara,
Yoshikazu; (Tokyo, JP) |
Correspondence
Address: |
Pillsbury Winthrop LLP
Intellectual Property Group
Ninth Floor
1100 New York Avenue, NW.
Washington
DC
20005-3918
US
|
Family ID: |
26591614 |
Appl. No.: |
09/851428 |
Filed: |
May 9, 2001 |
Current U.S.
Class: |
349/151 |
Current CPC
Class: |
G02F 1/133512
20130101 |
Class at
Publication: |
349/151 |
International
Class: |
G02F 001/1345 |
Foreign Application Data
Date |
Code |
Application Number |
May 10, 2000 |
JP |
2000-137368 |
May 16, 2000 |
JP |
2000-143549 |
Claims
1. A method of manufacturing a flat-panel display device including
steps of attaching an elongate light-control tape onto a
non-displaying area of a display cell so as to control light
transmittance upon the non-displaying area, said display cell being
light-transmissive and arranged with a plurality of pixels in a
displaying area, said steps of attaching comprising: a step of
determining a pasting-start position for pasting a start end of the
light-control tape on the display cell; a step of taking out the
start end of the light-control tape by drawing to peel a release
sheet covering a downward-facing adhesive face of the light-control
tape, said release sheet being drawn reverseward to a direction of
the taking out of the start end; a step of positioning the start
end of the light-control tape to the pasting-start position; a step
of pressing the start end of the light-control tape onto the
pasting-start position by a rotatable press roller; a step of
continuously pasting the light-control tape onto the display cell
by moving the display cell in the direction of the taking out of
the start end while keeping the light-control tape being pressed by
the press roller; a step of cutting the light-control tape when the
light-control tape is pasted by a predetermined length; and a step
of completing of pasting a cut piece of the light-control tape onto
the display cell, by use of the press roller, up to a cut end of
the light-control tape.
2. The method of manufacturing a flat-panel display device
according to claim 1, wherein said display cell is of a liquid
crystal display and has a polarizer at a main surface thereof; said
step of determining a pasting-start position further comprising a
step of width-wise positioning of the light-control tape in respect
of an edge of the polarizer.
3. The method of manufacturing a flat-panel display device
according to claim 1, further comprising a step of attaching tape
carrier packages onto said display cell by compression bonding
procedure, before said steps of attaching a light-control tape.
4. The method of manufacturing a flat-panel display device
according to claim 3, further comprising a step of soldering for
connecting the tape carrier packages with a wiring board after said
step of attaching tape carrier packages onto said display cell,
before said steps of attaching a light-control tape.
5. A method of manufacturing a flat-panel display device including
steps of attaching a light-control tape onto a non-displaying-side
main face of a light-trasmissive display cell along edge-wise
direction of the display cell, said display cell being
light-trasmissive and arranged with a plurality of pixels in a
matrix arrangement at a displaying area on a displaying-side main
face thereof, said steps of attaching comprising: a step of placing
the display cell on a movable stage; a step of positioning a start
end of the light-control tape to a pasting-start position of a
to-be pasted area, on the display cell, for pasting the
light-control tape; a step of pressing the start end of the
light-control tape onto the pasting-start position by a press
roller rotatable along one direction; and a step of continuously
pasting the light-control tape onto the to-be pasted area by moving
the movable stage along a rotating direction of the press roller;
said step of continuously pasting being comprised of a step of
cutting the light-control tape, while moving the movable stage, by
a length substantially tantamount to the to-be pasted area.
6. The method of manufacturing a flat-panel display device
according to a claim 5, said movable stage being moved until said
press roller passes through a cut end of the light-control
tape.
7. The method of manufacturing a flat-panel display device
according to claim 5, wherein, while said display cell has
polarizers at main surfaces thereof, said step of positioning the
start end of the light-control tape is made in respect of an edge
of the polarizer.
8. The method of manufacturing a flat-panel display device
according to claim 6, said light-control tape being pasted onto the
to-be pasted area such that an edge of the polarizer and a
longitudinal edge of the light-control tape are brought into tight
contact with each other.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method of manufacturing a
flat-panel display device including a process for pasting a
light-control tape in an elongated shape, which serves to control
light transmittance, onto a display cell (display panel proper), in
a flat-panel display device such as a liquid-crystal display
device.
[0002] A flat-panel display device of a light-transmissive mode,
such as a liquid-crystal display device, has a back light on a rear
side of the display cell in order to irradiate the display cell. On
a rear main face of the display cell, a light-control tape is
pasted, in order to prevent light from the back light and the like
from leaking through non-displaying area outside the viewing area
(a real or effective displaying area) of the display cell to reach
a viewer.
[0003] Steps of pasting the light-control tape are, for example, as
follows.
[0004] After carrying out an outer lead bonding (OLB) process for
connecting tape carrier packages (TCPs) onto peripheral portion on
the display cell, there is carried out a soldering process for
soldering the TCPs onto a wiring board. After the soldering
process, with the rear main face of the display cell being kept
facing upside, an operator manually pastes the light-control tape
on the rear main face.
[0005] Such manner of pasting the light-control tape poses a
problem that accuracy of the pasting varies with the operator and a
problem that a complicated operation is required for the operator.
Particularly, in respect of the accuracy, length of the
light-control tape have to be longer than that of a polarizer stuck
on the rear main face of the display cell while the light-control
tape have to be prevented from extruding beyond outline of the
glass substrate. Further, it is necessary that a gap between the
light-control tape and the polarizer is made equal to or smaller
than 1 mm. These require a very difficult operation.
[0006] Hence, in view of the above-described problems, it is an
object of the invention to provide a method of manufacturing a
flat-panel display device capable of pasting the light-control tape
to the display cell easily and accurately.
[0007] BRIEF SUMMARY OF THE INVENTION
[0008] According to an aspect of the invention, a method of
manufacturing a flat-panel display device includes steps for
attaching an elongate light-control tape onto a non-displaying area
of a display cell (display panel proper), so as to control
(especially, shield or reflect) light transumittance or light
incident upon the non-displaying area, said display panel cell
being light-transmissive and arranged with a plurality of pixels in
a displaying area, said steps for attaching comprising: a step of
determining a start position for pasting a start end of the
light-control tape on the display cell; a step of taking out the
start end of the light-control tape by drawing to peel a release
sheet covering a downward-facing adhesive face of the light-control
tape, said release sheet being drawn reverseward to a direction of
the taking out of the start end; a step of positioning the start
end of the light-control tape to the start position; a step of
pressing the start end of the light-control tape onto the start
position by a rotatable press roller; a step of continuously
pasting the light-control tape onto the display cell by moving the
display cell in the direction of the taking out of the start end
while keeping the light-control tape being pressed by the press
roller; a step of cutting the light-control tape when the
light-control tape is pasted by a predetermined length; and a step
of completing of pasting a cut piece of the light-control tape onto
the display cell, by use of the press roller, up to a cut end of
the light-control tape.
[0009] According to another aspect of the invention, said display
cell is of a liquid crystal display and has a polarizer at a main
surface thereof; said step of determining a start position further
comprising a step of width-wise positioning of the light-control
tape in respect of an edge of the polarizer.
[0010] According to a still another aspect of the invention, the
method further comprises a step of attaching tape carrier packages
onto said display cell by compression bonding procedure, before
said series of steps for pasting.
[0011] According to further aspect of the invention, the method
further comprises a step of soldering for connecting the tape
carrier packages with a wiring board after said step of attaching
onto said display cell, before said series of steps for
pasting.
[0012] An explanation will be given of a series of steps for
pasting the light-control tape in the elongated shape to the
display cell, in accordance with invention-wise method of
manufacturing the flat-panel display device.
[0013] In the first step, the pasting position for pasting the
start end of the light-control tape to the display cell is
determined or confirmed. In this step, width-wise positioning of
the light-control tape is carried out based on an edge of the
polarizer, which is already stuck on the display cell.
[0014] In the second step, the start end of the light-control tape
is taken out by drawing to peel a release sheet covering a
downward-facing adhesive face of the light-control tape, said
release sheet being drawn reverseward to a direction of the taking
out of the start end.
[0015] In the third step, the start end of the light-control tape
is positioned to the pasting-start position.
[0016] In the fourth step, the start end of the light-control tape
is pressed onto the pasting-start position by the rotatable press
roller.
[0017] In the fifth step, the light-control tape is continuously
pasted onto the display cell by moving the display cell in the
direction of the taking out of the start end while keeping the
light-control tape being pressed by the press roller.
[0018] In the sixth step, the light-control tape is cut at a
predetermined position when the light-control tape is pasted by a
predetermined length.
[0019] In the seventh step, a cut piece of the light-control tape
is further pasted onto the display cell by use of the press roller,
up to a cut end of the light-control tape.
[0020] By using such a manufacturing method, the light-control tape
can be pasted onto the display cell easily and accurately without
using manual labor
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a bottom view of a display cell (display panel
proper) showing an embodiment of the invention.
[0022] FIG. 2 is a perspective view of the display cell.
[0023] FIG. 3 is a sectional view taken along a line A-A in FIG.
2.
[0024] FIG. 4 is a sectional view taken along a line B-B in FIG.
2.
[0025] FIG. 5 is a side view of a pasting apparatus.
[0026] FIGS. 6A-6H illustrate explanatory views showing steps of
pasting a light-control tape by the pasting apparatus.
[0027] FIG. 7 is an exploded perspective view of essential portions
of the display cell.
[0028] FIG. 8 is a schematic perspective view for explaining how a
TCP is positioned in respect of the display cell in an OLB
process.
[0029] FIG. 9 is a schematic vertical sectional view similarly for
explaining how a TCP Is positioned in respect of the display
cell.
DETAILED DESCRIPTION OF THE INVENTION
[0030] An explanation will be given of a method of manufacturing a
liquid-crystal display device 10 according to an embodiment of the
invention in reference to FIG. 1 through FIG. 9 as follows.
[0031] In the embodiment, the liquid-crystal display device is of
light-transmissive mode and has; a display panel, which is
comprised of a display cell (display panel proper) arranged with a
plurality of pixels in a matrix arrangement, and of driver circuits
for driving the display cell; and a back light for irradiating the
display cell. The driver circuits are formed on TCPs and a wiring
board.
[0032] The "light-transmissive mode" is meant to encompass not only
those in which light for displaying is solely provided by the back
light, but those in which light for displaying is provided partly
by outside light or front light and partly by the backlight, that
is, in a mode of joint use of transmissive and reflective light.
Thus, in this specification, the "light-transmissive mode" means a
display mode where back light arranged on non-displaying side of
the display cell is a main source of light for displaying and where
utilization ratio of outside light or front light is rather smaller
compared with "light-reflective mode". The outside light means the
light incident upon a displaying-side main surface of the display
cell, while the "light-reflective mode" means a display mode where
back light is not arranged on non-displaying side of the display
cell and where light for displaying is provided by the outside
light and/or a front light.
[0033] Although the back light is meant to irradiates the display
area on the display cell, which is arranged with pixels in a matrix
arrangement, light from the back light may leak through
non-displaying area other than the display area, to viewer's side.
Thus, in order to prevent the light leakage, some countermeasures
is needed for preventing light transmission at the non-displaying
area, on non-displaying side or side of the back light of the
display cell. Especially, when the polarizer on displaying-side
main face of the display cell is smaller than an opening of a bezel
cover and thereby an edge of the polarizer is located within an
opening of the bezel cover, it is strongly desired to prevent the
light leakage by using a light-control tape. According to the
embodiment, the light-control tape is arranged at the
non-displaying area on non-displaying-side main face of the display
cell to thereby prevent transmission of undesired light from the
back light.
[0034] Normally, in the liquid-crystal display device, the
polarizers are respectively arranged at positions in correspondence
with display areas of the display face of the display cell and a
face opposed to the display face (face on the side of the back
light).
[0035] The light-control tape is arranged in tight contact with the
polarizer arranged at back-light-side or non-displaying-side main
face of the display cell, which is rear main face of the display
cell. Width of the light-control tape is set such that light of the
back light incident upon a surrounding of the display area is not
transmitted to the viewer's side or displaying side. That is, the
light-control tape is provided along every edges of the rectangular
polarizer on the rear main face of the display cell so as to
surround the polarizer. It is preferable that the light-control
tape is arranged to completely cover out a surrounding area not
covered by the polarizer on the rear main face of the display cell.
Thus, It is preferable that the width of the light-control tape is
determined respectively at along the edges of the polarizer to
constitute a width from an end portion of the polarizer to an end
portion of the display cell. Nevertheless, the width of the
light-control tape is so designed, in consideration of an accuracy
of pasting the polarizer, that the light-control tape does not
outwardly protrude from edges of the display cell.
[0036] In following, an explanation will be given of a case of
pasting the light-control tape along every edges of the display
cell. However, the embodiment is not limited thereto but the
light-control tape may be provided only along an edge or edges
where light leakage has to be prevented, in conformity with designs
and requirements of variety of products.
[0037] A brief explanation will be given of an outline of a method
of manufacturing the liquid-crystal display panel 10 that includes
driver circuits, in following two paragraphs.
[0038] An array substrate 12 and opposed substrate 14 having an
opposed electrode, each of which substrate is comprised of a
light-transmissive insulating substrate such as a transparent glass
substrate, are bonded together with interposing a layer of liquid
crystal material between them; to thereby form a display cell
(display panel proper) 16. Subsequently, after cutting out or
chamfering the edges of the display cell 16, two polarizers 18 are
pasted or stuck respectively onto the displaying-side main surface
and the rear or back-light-side main face of the display cell. When
the liquid crystal material is of twisted nematic (TN) type for
example, the two polarizers 18 are arranged such that their
light-transmissive orientation or polarizing axes are orthogonal to
each other.
[0039] The liquid-crystal display panel 10 is completed by
following processes; an outer lead bonding (OLB) process for
attaching tape carrier packages (TCPs) onto the display cell 16
assembled as described above (refer to FIG. 7 through FIG. 9); a
soldering step for attaching a wiring board onto the TCPs; and a
pasting process for pasting the light-control tape (refer to FIG. 1
through FIG. 3).
[0040] <Outer Lead Bonding>
[0041] An explanation will be given of an outer lead bonding (OLB)
process. In this process, a plurality of signal-line TCPs 22 are
attached on a longer edge portion of the rectangular display cell
16, on which a connection pads 20 for a plurality of signal lines
are arranged, with compression bonding the TCPs 22 onto the
connection pads 20 by using an anisotropic conductive film (ACF)
102 interposed between them. Meanwhile, a plurality of
scanning-line TCPs 26 are attached on a shorter edge portion of the
display cell 16, on which a connection pads 24 for a plurality of
scanning lines are arranged, with compression bonding the TCPs 26
onto the connection pads 24 by similarly using an ACF 102.
[0042] A detailed explanation will be given of a step of
positioning and compression bonding signal-line TCPs 22 in
reference to FIG. 7, FIG. 8 and FIG. 9 as follows. A similar step
is carried out also for scanning-line TCP 26.
[0043] FIG. 7 is an exploded perspective view of essential portions
of the liquid-crystal display panel 10; FIG. 8 is a schematic
perspective view for explaining how a TCP 22 is positioned in
respect of the display cell 16; and FIG. 9 is a vertical sectional
view corresponding the FIG. 8.
[0044] TCP 22 has a slender driver IC chip 125 on a flexible
insulating substrate 110, which IC chip is arranged, for example,
in a longitudinal direction of the substrate substantially in a
rectangular shape.
[0045] The TCP 22 also has an output terminal group 112 for
outputting output signals from the driver IC chip 125, on an
output-side edge 22a, which is a display-cell-side longer edge of
the flexible insulating substrate 110. The output terminal group
112 is comprised of lead wire terminals 116 arranged along the
output-side edge 22a. The lead wire terminals 116 are distal ends
of a wiring group that is extended from the terminals of the driver
IC chip 125 to the output-side edge 22a.
[0046] The flexible insulating substrate 110 is formed of a
polyimide film, while the output terminal group 112 and the wiring
group are formed of a pattern of a copper foil.
[0047] It is noted that the output terminal group 112 includes not
only connection terminals for supplying signals to a pixel area but
also connection terminals for a power source line, a ground line
and the like. A terminal arranging pitch of the output terminal
group 112 is, for example, equal to or smaller than 0.06 mm.
[0048] The TCP 22 also has aligning/inspecting portions 113
comprising dummy terminals, that is, non-electrically-connecting
terminals, on both ends of the output terminal group 112. A wiring
pattern of the aligning/inspecting portion 113 is used for aligning
with a peripheral connecting area 153 on the display cell 16. This
wiring pattern is used also for inspecting a compression bonding
state of ACF 102. The aligning/inspecting portion 113 is formed of
a wiring pattern of copper foil and is formed simultaneously with
formation of the output terminal group 112 and the wiring group.
The wiring pattern on each aligning/inspecting portion 113 is
comprised of: inner and outer dummy lead wires 114, 115, which are
arranged substantially in parallel with the respective lead wire
terminals 116 of the output terminal group 112; and a branch wire
117. The branch wire 117 is extended orthogonally and outwardly
from the outer dummy lead wire 114 and is arranged along the
output-side edge 22a.
[0049] The branch wire 117 is extended in a direction (hereinafter,
referred to as X direction) along an edge 151a of the display cell
16, to which TCPs 22 are mounted. The outer dummy lead wire 114 is
extended in Y direction and serves for positioning a TCP 22 in X
direction when to mount the TCP 22. That is, the outer dummy lead
wire 114 and the branch wire 117 continuous thereto, constitute an
aligning mark 111 on the TCP 22.
[0050] Meanwhile, the inner dummy lead wire 115 is made to overlap
a wire-omitting portion 135 on the display cell 16 and serves for
determining or evaluating a state of the anisotropic conductive
film (ACF) 102 or a state of the compression bonding, as described
later.
[0051] As for the display cell 16, the array substrate 12 protrudes
like a shelf from an edge 152a of the opposed substrate 14 to form
the peripheral connection area 153, on which connection pad groups
20 are arranged and TCPs 22 are mounted. Each connection pad group
20 is for connecting with respective TCP 22. At each of portions
133 sandwiching the connection pad group 20 from pad-arranging
direction (X direction), there are provided an aligning mark 131
and the wire-omitting portion 135 respectively in correspondence
with the aligning mark 111 and the dummy lead wire 115 on the TCP
22.
[0052] The aligning mark 131 comprises a dummy lead wire 134
overlapping the outer dummy lead wire 114 on the TCP 22 and a
branch wire 137 overlapping the branch wire 117 on the TCP 22. The
aligning mark 131 is formed simultaneously with etching processes
for forming TFTs and other patterns on the array substrate 12.
There is a disconnected portion at center of the dummy lead wire
134; and the dummy lead wire 134 is separated to an outer portion
134a proximate to the edge 151a of the display cell 16 and an inner
portion 134b.
[0053] The disconnected portion serves as a window (X-direction
aligning window 131X) for observing both edges of the outer dummy
lead wire 114 on the TCP 22, from a lower side of the peripheral
connection area 153 through the transparent array substrate 12,
when the outer dummy lead wire 114 is made to over lap the dummy
lead wire 134 on the display cell 16. Through the disconnected
portion or X-direction aligning window 131X, positions of both
edges of the dummy lead wires can firmly be caught even when center
lines of the dummy lead wires 114 and 134 substantially coincide
with each other. This is achieved in particular by constituting the
width of the dummy lead wire 114 on the side of TCP 22 smaller than
the width of the dummy lead wire 134 on the display cell 16.
[0054] Further, there is a disconnected portion between a root of
the branch wire 137 and the outer edge 134a of the dummy lead wire
134. This disconnected portion constitute a window for positioning
in Y direction (Y-direction aligning window 131Y) for catching the
branch wire 117 on the TCP 22 overlapped to the branch wire 137
when observed from the lower side of the peripheral connection area
153. The Y-direction aligning window 131Y may be provided at a
middle of the branch wire 137, instead of its root portion.
[0055] The output terminal group 112 on the TCP 22 is aligned and
electrically connected with the connection pad group 20 on the
display cell 16, through an ACF 102 in a shape of a tape having
substantially a constant width. The TCP 22 and the display cell 16
are also mechanically connected to each other through the ACF
102.
[0056] In the above, the lead wires 114 and 134 constituting the
aligning marks 111 and 131 on TCP 22 and the display cell 16, are
explained as dummy lead wires. However, the lead wires 114 and 134
can also be used for a ground wiring, for a power source line or
for inputting a signal to the display cell 16.
[0057] In following, steps for aligning the output terminal group
112 on the TCP 22 and the connection pads 20 on the display cell
16, by referring FIG. 7 through FIG. 9.
[0058] (1) A piece of ACF 102 cut in a predetermined length is
pasted to an area of the output terminal group 112 of TCP 22.
[0059] (2) TCP 22 is mounted to a TCP transporting instrument 107
having a vacuum chuck 171 and is transported until the output
terminal group 112 of TCP 22 reaches a region of the connection pad
group 20 on the peripheral connection area 113 (state of FIG. 9).
At this occasion, as shown by FIG. 9, the display cell 16 is
mounted on a mounting table 106 and is projected from an end edge
of the mounting table 106 by an amount of the peripheral connection
area 153 like a shelf.
[0060] (3) A pair of CCD cameras 104 of an automatic recognizing
apparatus are used which are arranged on the lower side of the edge
151a of the array substrate 12. Through the CCD cameras 104, there
are caught positions of the outer dummy lead wires 114 and the
branch wires 117, which are disposed on both ends of the output
terminal group 112 of TCP 22, and positions of the dummy lead wires
134 and branch wires 137 disposed at corresponding portions of the
display cell 16. When the dummy lead wires 114 and the branch wires
117 cannot be caught in the CCD cameras, the position of TCP is
pertinently adjusted by the TCP transporting instrument 107.
[0061] (4) Based on grasping the positions, there is calculated
required amount of shifting in position of TCP 22 so as the dummy
lead wire 114 and the branch wire 117 on the TCP 22 to superimpose
the corresponding dummy lead wire 134 and the corresponding branch
wire 137 on the display cell 16. In more detail, there are
calculated the required amount of shifting in X direction and Y
direction and the required amount of shifting in a rotational
direction .theta. from X direction to Y direction.
[0062] (5) Based on the above calculation, there are carried out a
required amount of traveling in X direction and Y direction and a
required amount of rotation.
[0063] (6) By a screen image on a monitor 108 connected with the
CCD cameras 104 of the automatic recognizing apparatus, extents of
superimposition are evaluated, which includes an extent of
superimposing the dummy lead wire 114 on the TCP 22 and the dummy
lead wire 134 on the display cell 16; and an extent of super
imposing the branch wire 117 and the branch wire 137. In detail, as
shown at a lower part of FIG. 7, there are grasped amounts of
deviation in X direction and Y direction from correctly
superimposed positions, by catching positions of contours of the
outer dummy lead wires 114 in an X-direction aligning window 131X,
and by catching positions of contours of the branch wires 117 in an
Y-direction aligning window 131Y.
[0064] For example, firstly, in order to find the amount of
deviation in X direction, there is calculated a position of a
center line of the dummy lead wire 114 on the TCP 22 from positions
of both edges of the dummy lead wire 114 appearing in the window
131 X. Next, there is calculated a center line of the dummy lead
wire 134 on the display cell 16 from contours on edges of the dummy
lead wires 134a, 134b. Further, there is calculated amount of
deviation between the center line of the dummy lead wire 114 and
the center line of the dummy lead wire 134, at the center portions
of the window 131 X.
[0065] An amount of deviation in the rotational direction can also
be found by the amounts of deviation in X direction and Y
direction.
[0066] If the amounts of deviation are equal to or larger than
certain values, the position of TCP 22 is adjusted.
[0067] (7) When the alignment has been finished in this way,
pre-bonding is made and then thermo compression bonding is carried
out by a heat tool.
[0068] (8) After finishing the thermo compression bonding, there is
inspected and confirmed an extent of aligning the TCP 22 and the
display cell 16 and an extent or state of a compression bonding of
the ACF 102 as follows.
[0069] As shown at the lower stage of FIG. 7, there is adjusted the
position, etc. of the CCD camera 104 relative to the display cell
16 such that the aligning windows 131X and 131Y in X direction and
Y direction and the inner dummy lead wire 115 on the TCP 22 fall in
the field of view of the CCD camera 104.
[0070] (9) Accuracy of the aligning is evaluated by observing the
aligning windows 131X and 131Y in X direction and Y direction
similar to the above-described aligning procedure.
[0071] (10) By observing the inner dummy lead wire 115 on the TCP
22 overlapping the wire-omitting portion 135 on the display cell
16, there is found `an extent of crushing` of conductive particles
in the ACF 102. That is, there is observed a shape or state of the
conductive particles after thermo compression bonding and in
particular to what extent the conductive particles are crushed and
two-dimensionally spread out along the substrate face.
[0072] (11) When there is discovered a failure of positioning or
compression bonding of ACF 102 as described above, a portion of
bonding TCP 22 and the display cell 16 is peeled off by heating the
compression bonding portion. Then, steps for pasting, positioning
and compression bonding of ACF 102 are repeated.
[0073] In the above explanation, the alignment procedure is carried
out by an automatic system using the automatic recognizing
apparatus. However, the positioning can be carried out quite
similarly even by a manual system.
[0074] Further, in the above explanation, a piece of ACF 102 is
pasted and thereafter mounted to the terminal face of TCP 22.
However, the piece of ACF 102 may be pasted onto the connection pad
group 20 on the display cell 16. In this case, the piece of ACF 102
may be used for mounting a plurality of TCPs 22 by arranging the
single piece of continuous tape (ACF 102) to cover a plurality of
the connection pad groups 20 along an edge of the display cell
16.
[0075] In the above explanation, there is used anisotropic
conductive film supplied as a tape, the anisotropic conductive film
may be formed by coating a paste onto required areas.
[0076] According to the embodiment, alignment in mounting a tape
carrier package can be carried out reliably and easily; and
alignment error due to erroneous recognition of the aligning mark
is able to be suppressed.
[0077] Further, since the aligning marks on the tape carrier
package is constituted by the elongated lead wire and the branch
wire continuous thereto, even when the tape carrier package is
peeled off in repairing, the aligning marks would not be easily
peeled off.
[0078] Further the aligning mark and the portion for inspecting the
compression bonding state of ACF 102 are arranged proximately to
each other; and accordingly, the efficiency of inspecting the tape
carrier package after mounting can be promoted.
[0079] <Attaching and Connecting of TCPs onto a Wiring
Board>
[0080] Each of the wiring board is attached and connected with the
TCPs by soldering. An explanation will be given of a soldering
process.
[0081] After mounting TCPs 22 and TCPs 26 on the display cell 16 by
compression bonding as described above, each of wiring boards 30
and 31 is respectively soldered to TCPs 22 and TCPs 26.
[0082] When aligning a TCP and a wiring board, this wiring board
and the array substrate 12 are also aligned. For this reason, there
are provided aligning marks 28 at corner portions of surface on the
array substrate. The aligning marks 28 are formed simultaneously
with etching processes for forming TFTs (thin film transistors) on
the array substrate 12. The aligning marks 28 are formed
simultaneously also with the aligning marks 131 used for aligning
TCPs and the array substrate 12.
[0083] For the aligning, a pattern recognition using an image
processing is carried out by taking pictures of the aligning marks
28 on the array substrate from the rear main face on the array
substrate 12. After the aligning, a wiring board 30 or 31 is
soldered to TCPs 22 or TCPs 26.
[0084] Common aligning marks may be used as aligning marks 28 for
this process and as the aligning marks 131 for aligning TCPs and
the array substrate 12.
[0085] <Pasting the Light-Control Tape>
[0086] In a following manner, light-control tapes 32 are pasted
onto the display cell 16.
[0087] The light-control tape 32 is pasted, for example, along
every edges of the rectangular displaying area, that is real or
effective viewing area, on the rear main face of the display cell
16, so as to prevent light of the back light from leaking through
non-displaying area outside the displaying area, to viewer's side.
In an example illustrated in FIG. 1, the light-control tape 32 is
pasted along a longer edge of the rear main face of the display
cell 16.
[0088] The light-control tape 32 have to be pasted along an edge of
a polarizer 18 in a manner not forming a gap between the polarizer
18 and the light-control tape 32, to prevent light from leaking. In
the embodiment, the light-control tape 32 reflects light from the
back light to thereby prevent undesired light from transmitting to
viewer's side. It is noted that side-edge faces of the array
substrate 12 are covered with a bezel cover when the display device
is assembled; thus, arising no need for the light-control tape 32
on the side-edge faces.
[0089] The light-control tape 32 is comprised of; an elongated
synthetic resin film such as polyester film of black color; a light
shielder formed of aluminum coated on face-side surface of
synthetic resin film by vapor deposition; and a coating of adhesive
applied on back-side surface of the synthetic resin film. The light
shielder reflects light from the back light at its surface of
deposited aluminum metal. Meanwhile, the synthetic resin film, in
black color or the like, serves to absorb outside light.
[0090] Whereas the light shielder is formed of the light-reflecting
material in this embodiment, the light shielder may be formed of
other light-absorbing material to thereby prevent undesired light
from transmitting therethrough.
[0091] When the light-control tape 32 is supplied by its provider,
a release sheet (an easily peelable sheet) 34 covers the adhesive
on its back-side surface, or adhesive face of the light-control
tape 32, while the light-control tape 32 is wound around a reel to
form a film roll. The width of the light-control tape 32 falls in a
range of 1 mm through 4 mm and the width of the light-control tape
is determined in accordance with a distance from an edge of the
polarizer 18 to a respective edge of the glass substrate, on the
rear main face the display cell. Meanwhile, the thickness of the
light-control tape is 0.1 mm. The light-control tape is arranged on
non-displaying area, which is outside the displaying area, on the
array substrate 12 and is arranged along each edges of the array
substrate 12 in such a manner that elongated direction of the
light-control tape coincides with respective edge of the array
substrate 12. Further, width and length of the light-control tape
32 is so set that the light-control tape 32 does not extrude from
outline edges of the array substrate 12 and does not overlap the
polarizer 18. In the embodiment, the width of the light-control
tape 32 is so set that the light-control tape 32 is inwardly
distanced by 0.5 mm from designed position of the outline edge of
the array substrate, when the light-control tape 32 is arranged in
tight contact with an edge of the polarizer 18. Such setting of the
width is made so as the light-control tape 32 having a
predetermined width not to protrude from the outline edge of the
array substrate 12, in consideration of some possible deviation in
stuck position of the polarizer 18 for example.
[0092] FIG. 5 shows an example of a pasting apparatus for pasting
the light-control tape 32 onto the display cell 16, in a schematic
side view.
[0093] A pasting apparatus 36 is arranged with a movable stage 40
on abase 38 or table movably in one direction (X direction). The
display cell 16 is placed on the movable stage 40. Meanwhile, a
main body 42 of pasting apparatus 36 is erected on the base 38.
[0094] At a top portion of a main body 42, a light-control tape 32
is arranged in a wound film roll; and the light-control tape 32 is
drawn from the wound film roll, along a drawing-out body 44
projected from a side portion of the main body 42. A lower face of
the drawing-out body 44 is inclined toward the movable stage 40
such that the light-control tape 32 is guided toward the movable
stage 40. Meanwhile, in the wound film roll, the adhesive face of
the light-disposing 32 tape faces outward; and thus, when drawn,
the adhesive face of light-control tape 32 faces downward and
toward the display cell 16.
[0095] A recess 46 is provided on the lower face of the drawing-out
body 44, which is on intermediate portion of a course of drawing
out the light-control tape 32; and a cutter 50 of a cutter
apparatus 48 is arranged to be insertable into the recess 46. When
the cutter apparatus 48 is operated to insert the cutter 50 into
the recess 46, the light-control tape 32 is cut, if the
light-control tape 32 is being moved along the lower face of the
drawing-out body 44.
[0096] Beneath the drawing-out body 44, a peeler roller 52 is
provided for peeling the release sheet 34 from the light-control
tape 32. The peeler roller 52 is driftable in the drawing-out
direction of the light-control tape 32, by action of a moving
apparatus 54 that is comprised of a motor or an air cylinder.
[0097] The peeler roller 52 draws out the light-control tape 32
from the film roll and peels off the release sheet 34 from the
light-control tape 32. Details are as follows; by drifting the
peeler roller 52 in the drawing-out direction, the light-control
tape 32 is drawn out such that a start end of the light-control
tape is disposed at beneath a press roller 56; then, there lease
sheet is peeled off from the light-control tape 32 by drifting back
the peeler roller 52 in a direction reverse to the drawing-out
direction.
[0098] The press roller 56 is provided at ahead (leftward in the
FIG. 5) of the drawing-out body 44 for pressing the light-control
tape 32 drawn out along the lower surface of the drawing-out body
44. The press roller 56 is driftable in vertical direction by
action of a vertical moving apparatus 58 comprising a motor or air
cylinder.
[0099] An explanation will be given of steps for pasting the
light-control tape onto the display cell 16 by using the pasting
apparatus 36 having the above-described constitution in reference
to FIG. 6.
[0100] <1st step> First, the display cell 16 is placed on the
movable stage 40, with the array substrate 12 being upside (that
is, the rear main face or back-light side face in completed display
device is upside). Then, there is detected a pasting-start position
for pasting a start end of the light-control tape 32 that is drawn
out from the lower face of the drawing-out body 44 by a
predetermined length. In order that the start end of the
light-control tape 32 is positioned in X direction (that is, in the
drawing out direction of the light-control tape 32), the movable
stage 40 and the display cell 16 are fixed to predetermined
positions while position of the drawing-out body 44 is numerically
controlled and fixed. Meanwhile, with regard to the width direction
of the light-control tape 32, that is, Y-axis direction, a position
of an edge of the polarizer 18 is detected and determined.
Specifically, the surface of the display cell 16 mounted on the
movable stage 40 is scanned by a stepped portion-detecting sensor;
detected stepped portions at around presumable position of the edge
of the polarizer 18 is taken as position of the edge of the
polarizer; and one edge of the light-control tape 32 is brought at
the detected edge of the polarizer 18.
[0101] As described above, the start end of the light-control tape
32 is positioned to the pasting-start position.
[0102] <2nd step> After positioning the start end of the
light-control tape 32 to the pasting-start position, the press
roller 56 is brought downward so that the adhesive face of the
light-control tape 32 sticks onto the pasting-start position of the
display cell 16.
[0103] <3rd step> The movable stage 40 is drifted in the
drawing out direction (X direction) of the light-control tape 32
while the light-control tape 32 being pressed by the press roller
56. In this way, the light-control tape 32 is continuously pasted
onto the rear main face of the display cell 16 along its edge. In
same time, the release sheet is successively peeled off by the
peeler roller 52.
[0104] <4th step> When a predetermined length of the
light-control tape 32 is drawn out from the film roll under
numerical control, the light-control tape 32 is cut by the cutter
50 while being pressed by the press roller 56.
[0105] In this way, the light-control tape is pasted without
touching the adhesive face of the light-control tape 32, since the
light-control tape is cut while pasting of the light-control tape,
by the predetermined length. When a pre-cut piece of the
light-disposing in the predetermined length is used, it goes in
other manner. Further, because pressing of whole of the
light-control tape is feasible, automation of pasting the
light-control tape is easily achieved.
[0106] When the predetermined length of the light-control tape has
to be varied in accordance with variety of display device products,
setting of the pasting apparatus is easily changeable by numerical
control. Thus, change of the setting is much easier than a process
using the pre-cut light-control tape in the predetermined
length.
[0107] <5th step> The cut piece of the light-control tape 32
is further pasted onto the display cell 16 by the press roller 56
up to a cut end of the piece of the light-control tape 32.
[0108] Because whole of the cut piece of the light-control tape 32
is successively pressed and pasted by the press roller 56 up to the
cut end, accuracy of the pasting is excellent without causing
touching on the adhesive face of the light-control tape 32.
[0109] <6th step> After pressing the light-control tape 32 by
the press roller 56 up to the cut end, the press roller 56 is moved
upward. By the time of the movement, the cut piece of the
light-control tape 32 has already been pasted in a manner as shown
by FIG. 1 through FIG. 3.
[0110] <7th step> Since the start end of the cut
light-control tape 32 is disposed at the recess 46 on the
drawing-out body 44, the peeler roller 52 is moved in the drawing
out direction and along therewith, the start end of the
light-control tape 32 is taken to beneath the press roller 56.
After this, as mentioned above, the pasting-start position is
determined; and then the start end of the light-control tape 32 is
disposed at the pasting-start position.
[0111] <8th step> The release sheet 34 is peeled off from the
light-control tape 32 by moving the peeler roller 52 in the
direction reverse to the drawing out direction.
[0112] Then, operation of the pasting apparatus 36 returns to the
1st step and successively, the light-control tape 32 is pasted to a
next one of the display cell 16.
[0113] As mentioned above, by using the pasting apparatus 36, the
light-control tape 32 is pasted accurately and easily along the
edge of the polarizer 18.
[0114] Because the light-control tape is drawn out from the film
roll while pasting, and because the light-control tape is cut by
the predetermined length while pasting of the light-control tape,
automation of the pasting process is easily feasible without
causing touching on the adhesive face of the light-control
tape.
[0115] Further, after cutting the light-control tape by the
predetermined length, the cut piece of the light-control tape is
further pasted up to the cut end. Accordingly, because the total of
the light-control tape is pressed on by the press roller, accuracy
of the pasting is achieved.
[0116] Further, because the light-control tape is pasted after the
OLB step and soldering step, accurate alignments between the array
substrate and TCP and between TCP and the wiring board are
achievable, by using alignment marks for the OLB process arranged
at the peripheral connection area and by using alignment marks for
the soldering step.
[0117] The above construction, in which the light-control tape is
arranged on the rear main face of the display cell, is applicable
generally to a flat-panel display device of the "light-transmissive
mode".
[0118] <Industrial Applicability>
[0119] As mentioned above, according to the method of manufacturing
the flat-panel display device of the invention, the light-control
tape can be pasted to the display cell easily and accurately
without manual labor of an operator.
[0120] The entire disclosure of Japanese Patent Application
No.2000-143549 filed on May 16, 2000 and of Japanese Patent
Application No. 2000-137368 filed on May 10, 2000 including
specification, claims, drawings and summary are incorporated herein
by reference in its entirely.
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