United States Patent
`
`[19]
`
`[11] Patent Number:
`
`5,636,329
`
`
`Sukegawa et a1.
`[45] Date of Patent:
`Jun. 3, 1997
`
`US005636329A
`
`[54] LIQUID CRYSTAL DISPLAY APPARATUS
`HAVING TERMINAL PROTECTED FROM
`BREAK DOWN
`
`[75]
`
`Inventors: Osamu Sukegawa; Takahiko
`Watanabe; Wakahiko Kaneko, all of
`Tokyo, Japan
`
`[73] Assignee: NEC Corporation, Tokyo, Japan
`
`[21] Appl. No.: 493,537
`
`[22] Filed:
`
`Jun. 22, 1995
`
`[30]
`
`Foreign Application Priority Data
`
`Jun. 23, 1994
`
`[JP]
`
`Japan .................................... 6-163337
`
`Int. C1.6 ................................................... G02F 111343
`[51]
`[52] US. Cl.
`.............................................................. 349/149
`[58] Field of Search ................................... 359/88. 85, 83
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`FOREIGN PATENT DOCUMENTS
`64-19324
`1/1939
`J
`....................................... 359/33
`4-32821
`2/1992
`1:11:23.
`Primary Examiner—William L. Sikes
`Assistant Examiner—James A. Dudek
`
`Attorney, Agent, or Firm—Young & Thompson
`
`[57]
`
`ABSTRACT
`
`A lower layer metal wiring is led out from a display portion
`to a terminal portion provided to the periphery of the glass
`substrate and covered at the upper surface with an interlayer
`insulation film. An upper layer metal wiring formed on the
`interlayer insulation film is connected to the lower layer
`metal wiring by way of contact holes formed in the inter—
`layer insulation film. The upper layer metal wiring is com-
`pletely covered by the transparent conductive film. A pro-
`tective insulation film is formed on the transparent
`conductive film, and an opening is made in to the protective
`insulation film in the terminal portion. In the terminal
`portion, copper foil wirings of a flexible wiring substrate are
`connected by way of an anisotropic conductive film. The
`upper layer metal wiring is removed at a portion not pro-
`tected by the protective insulation film or the anisotropic
`conductive film.
`
`5,187,604
`5,311,341
`
`........................ 359/88
`2/1993 Taniguchi et a1.
`5/1994 Hirai
`......................................... 359/88
`
`14 Claims, 6 Drawing Sheets
`
`
`
`8
`'6 7-2/14
`
`
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`
`
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`FOR
`
`DISPLAY
`PORTION
`
`
`
`CMI Exhibit 1005
`1
`
`CMI Exhibit 1005
`1
`
`

`

`US. Patent
`
`Jun. 3, 1997
`
`Sheet 1 of 6
`
`5,636,329
`
`
`
`FIG. 1A
`PRIOR ART
`
`
`
`
`
`
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`PORTIONA
`
`
`FIG. 1B
`PRIOR ART
`
`CMI Exhibit 1005
`2
`
`CMI Exhibit 1005
`2
`
`

`

`US. Patent
`
`Jun. 3, 1997
`
`Sheet 2 of 6
`
`5,636,329
`
`—10_31b-3—10
`
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`
`FIC: 2A
`
`PRIOR ART
`
`PRIOR ART
`
`FIG. 28 ‘2
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`
`FIG. 20
`PRIOR ART
`
`CMI Exhibit 1005
`3
`
`CMI Exhibit 1005
`3
`
`

`

`US. Patent
`
`Jun. 3, 1997
`
`Sheet 3 of 6
`
`5,636,329
`
` 9
`
`
`
`7-1
`
`6
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`
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`TERMINAL
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`PORTION
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`PORTION
`
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`
`100
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`
`FIG. SB
`
`
`
`
`FOR
`TERMINAL\ \
`
`PORTiON
`
`§
`
`20
`
`100
`
`1
`
`CMI Exhibit 1005
`4
`
`CMI Exhibit 1005
`4
`
`

`

`US. Patent
`
`Jun. 3, 1997
`
`Sheet 4 of 6
`
`5,636,329
`
`
`
`9
`
`7—2
`
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`PORTION
`
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`
`FIG. 3E
`
`CMI Exhibit 1005
`5
`
`CMI Exhibit 1005
`5
`
`

`

`US. Patent
`
`Jun. 3, 1997
`
`Sheet 5 of 6
`
`5,636,329
`
`
`
`
`
`w.
`
`
`
`
`
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`
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`
`‘
`
`CMI Exhibit 1005
`6
`
`CMI Exhibit 1005
`6
`
`

`

`US. Patent
`
`Jun. 3, 1997
`
`Sheet 6 of 6
`
`5,636,329
`
`
`
`
`
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`FIG 53
`
`CMI Exhibit 1005
`7
`
`CMI Exhibit 1005
`7
`
`

`

`1
`
`2
`
`5,636,329
`
`LIQUID CRYSTAL DISPLAY APPARATUS
`HAVING TERMINAL PROTECTED FROM
`BREAK DOWN
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`
`The present invention relates to a liquid crystal display
`apparatus and. more particularly,
`to an improvement in
`active matrix substrate employed in such an apparatus.
`2. Description of the Related Art
`A liquid crystal display apparatus or device has been
`generally used in various fields such as oflice automation
`equipment, car—mounted equipment and measuring
`instruments, since the device has a feature of less consuming
`electric power and space saving. Among all, an active matrix
`type device has attracted attention as a display means
`capable of full color display and realizing high contrast and
`high refinement.
`The active matrix type liquid crystal display device
`includes an active matrix substrate provided with a plurality
`of pixels each having a switching element such as a thin film
`transistor. It is necessary to connect the substrate to a driver
`integrate circuit (IC). While various kinds of connection
`structures have been proposed, such a structure is generally
`employed that connecting terminals on the substrate are
`bonded by way of an anisotropic conductive film (ACF) to
`a tape—carrier package (TCP) having the driver IC.
`In such a structure, the terminal portion for connection is
`made of a metal Wiring layer covered with a chemically
`stable transparent conductive film, and a part of the trans—
`parent conductive film is attached or bonded to the aniso-
`tropic conductive film. The portion of the conductor portion
`of the terminal not bonded with the anisotropic conductive
`film is used as a checking terminal to check the electrical
`connection between the terminal of the tape—carrier package.
`That is, a measuring probe is applied to the conductor
`portion so as to check whether or not the tape-carrier
`package and the terminal are electrically connected.
`Since the transparent conductive fihn covering the metal
`wiring is composed of a metal oxide, it cannot be formed
`thick in view of insuring transparency. so that there may
`exist some pin-holes in the transparent conductive film. For
`this reason, the metal Wiring is subject to an atmosphere
`through the pin-poles, so that there occurs corrosion on the
`wiring. Further, even if there is no defect, the metal wiring
`also suffers from corrosion due to moisture permeating the
`transparent conductive fihn in a high temperature and high
`humidity atmosphere. As the corrosion proceeds, the wiring
`is disconnected or broken out finally.
`As a countermeasure against the moisture, the exposed
`portion at the terminal portion is considered to be covered
`with a silicone resin thereby providing shield from the
`external moisture. Although this can suppress corrosion in
`the metal wiring. it requires an additional step of coating the
`silicone resin resulting in increase in cost. Alternatively, the
`terminal portion of the active matrix substrate may be
`completely covered with the anisotropic conductive film. In
`this case, the corrosion of the wiring can be suppressed even
`Without coating the silicone resin. However, this results in a
`disadvantage that checking the connection between the
`carrier package and terminal portion is impossible because
`the measuring probe can not be applied to the conductor
`portion of the terminal portion.
`SUMMARY OF THE INVENTION
`
`It is. accordingly, an object of the present invention to
`provide a liquid crystal display apparatus having a terminal
`
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`portion capable of preventing corrosion of a Wiring layer
`without increasing the number of steps and without hinder-
`ing the checking function during the steps.
`In order to attain the foregoing object, a liquid crystal
`display apparatus according to the present invention has a
`plurality of terminals each including a conductor film, a
`transparent conductive having a first portion formed on the
`conductor fihn and a second portion extending from the first
`portion, and a protection film covering a part of the second
`portion of the transparent conductive film With leaving a
`remaining part of the second portion, the first portion being
`attached to a connection member to receive driving signals.
`In the constitution described above, the portion of the
`conductor film of the transparent conductive film except the
`above part is protected by the protection fihn and the
`connection member such as anisotropic conductive film or
`heat seal connector. The above part is used for a check pad.
`Accordingly, even if the transparent conductive film con-
`tains a defect or even if it is used in a high temperature and
`high humidity atmosphere, the conductor film is free from
`the effects of external atmosphere. The conductor film is
`thus protected from the Wiring against corrosion. Therefore,
`according to the present invention, reliability of the terminal
`portion can be improved without adding steps. Then, accord—
`ing to the present invention, since checking after connection
`with the driver circuit is possible at the terminal portion and
`the silicone resin coating step after the press bonding step of
`the driver circuit can be saved, it is possible to increase the
`productivity and reduce the cost of the liquid crystal display
`device.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The above and other objects, features and advantages of
`the present invention will be more apparent from the fol-
`lowing description taken in conjunction with the accompa—
`nying drawings, in which:
`FIG. 1(a) and FIG. 1(b) are, respectively, a plan View and
`a cross sectional View taken along line A—A for a terminal
`portion of the prior art;
`FIG. 2(a) to FIG. 2(c) are cross sectional views for
`explaining problems in the terminal portion of the prior art;
`FIG. 3(a) is a plan view for a terminal portion of a first
`embodiment according to the present invention;
`FIG. 3(b) is a cross sectional view taken along line B—B
`in FIG. 3(a);
`FIG. 3(c) is a cross sectional View for a display portion of
`an active matrix substrate;
`
`FIG. 3(d) is a cross sectional view for explaining a
`schematic connection state between an active matrix sub—
`strate and a tape-carrier package;
`FIG. 3(e) is a cross sectional view for explaining a
`connection state with a tape—carrier package in a terminal
`portion of an embodiment according to the present inven—
`tion;
`
`FIG. 4(a) is a plan view for a terminal portion of a second
`embodiment according to the present invention;
`FIG. 4(b) is a cross sectional View taken along line C—C
`in FIG. 4(a) for explaining a connection state with a tape-
`carrier package in a terminal portion of a second embodi—
`ment according to the present invention;
`FIG. 5(a) is a plan view for a terminal portion of a third
`embodiment according to the present invention; and
`FIG. 5(b) is a cross sectional View taken along line D—D
`in FIG. 5(a) for explaining a connection state with a tape-
`
`CMI Exhibit 1005
`8
`
`CMI Exhibit 1005
`8
`
`

`

`5,636,329
`
`3
`carrier package in a terminal portion of the third embodi-
`ment according to the present invention.
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`Prior to the description of the preferred embodiments
`according to the present invention, the prior art will be
`explained more specifically with reference to the drawings
`in order to facilitate understanding of the present invention.
`Referring to FIG. 1(a) and FIG. 1(b), a terminal portion
`according to the prior art includes a glass substrate 1, a lower
`layer metal wiring 2 made of Cr or the like, an interlayer
`insulating film 3 comprising a composite fihn of a silicon
`oxide film and a silicon nitride film. contact holes 6 formed
`in the interlayer insulation film 3 to expose a plurality of
`portion of the lower layer metal wiring 2. an upper layer
`metal wiring 7 made of Cr or the like formed on the film 3
`in contact with the respective portions of the wiring 2, a
`transparent conductive fihn 8 made of Indium—Tin—Oxide
`(ITO) and a protective insulating film 9 made of a silicon
`nitride film.
`
`As is apparent from FIG. 1(a) and FIG. 1(b), the upper
`layer metal wiring 7 in a terminal portion is completely
`covered with the transparent conductive film 8. Although
`only one terminal is illustrated in the figure, several hun-
`dreds of terminals are actually disposed on the substrate 1 in
`the vertical direction of FIG. 1(a).
`Turning to FIG. 2(a), a terminal portion of a tape-carrier
`package is connected to the terminal portion of the prior art
`shown in FIG. 1(a) and FIG. 1(b). Specifically, a copper foil
`Wiring 31b of a flexible wiring substrate 31 constituting the
`tape-carrier package is connected by way of an anisotropic
`conductive film 10 onto the terminal portion 100. A con—
`ductor portion of the terminal portion 100 not covered with
`the anisotropic conductive film 10 is used as a checking
`terminal to check electrical connection between the terminal
`100 and the tape—carrier package.
`Since the transparent conductive film 8 covering the metal
`wiring 7 is made of ITO, it is chemically stable by itself.
`However, since it has not so preferred moisture resistant
`function and can not be formed to a large fihn thickness in
`View of ensurance of transparency, the protective function to
`the metal wiring 7 is not so effective. For instance, as shown
`in FIG. 2(b), if a defect 11 such as a pin—hole is present in
`the transparent conductive fihn 9, the metal wiring 7 is
`exposed to an external atmosphere to result in corrosion
`portion 12. Further, even if there is no defect, the metal
`Wiring 2 also suffers from corrosion due to moisture per-
`meating the transparent conductive film in a high tempera-
`ture and high humidity atmosphere. If corrosion proceeds,
`the wiring can become completely disconnected, so that a
`control signal from a driver IC provided on the tape-carrier
`can not be transmitted from the terminal portion to the
`display portion.
`As a countermeasure, as shown in FIG. 2(c), it may be
`considered to cover the exposed portion of the terminal
`portion with a silicone resin 13 thereby providing shield for
`the exposed portion against external effects. However, in the
`prior art shown in FIG. 2(a), since a step of coating the
`silicone resin 13 is required, this results in increase in cost.
`Further, it has been proposed in Japanese Laid-Open
`Patent No. Hei 4-32821 to completely cover an entire
`terminal portion with a heat seal connector corresponding to
`the anisotropic conductive film. In such a constitution,
`corrosion of the metal wiring can be suppressed, but this
`brings about a disadvantage that checking after connection
`with the tape-carrier package by using the terminal portion
`is impossible.
`
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`4
`Referring now to FIG. 3, an actual active matrix substrate
`according to a first embodiment of the present invention has
`several hundreds of terminals arranged in parallel with each
`other along a peripheral portion 100 of a substrate 1.
`However, only terminal 100 of the terminals will be
`explained in this embodiment. Since the feature of the
`structure of this embodiment will be best understood by the
`production method, explanations will be made to the method
`of manufacturing the active matrix substrate of this embodi-
`ment.
`
`A chromium (Cr) film as an opaque conductive fihn is
`deposited to a fihn thickness of 140 nanometer on the entire
`surface of a glass substrate 1 by a sputtering process,
`followed by being patterned to form a lower layer metal
`wiring 2—1 for the terminal, as shown in FIG. 3(a). This
`lower metal wiring forms a gate electrode 2a for a thin film
`transistor located in a central portion of a substrate 1 as
`shown in FIG. 3(c). Also by the lower layer metal wiring, a
`lead wiring 2—2 is formed to connect the terminal metal
`fihn 2-1 to the gate electrode 2a, as shown in FIG. 3(a) and
`FIG. 3(b).
`Then, a cemposite film of a silicon oxide film and a silicon
`nitride film to form an interlayer insulating film 3 is formed
`to a film thickness in total of 500 nanometer so as to cover
`the glass substrate 1, the lower layer metal wiring 2 and the
`gate electrode 2a by a plasma enhanced CVD method.
`Successively, amorphous silicon films are deposited on the
`interlayer insulating fihn 3 in identical CVD apparatus in
`order. The amorphous films are a non-doped amorphous
`silicon film 4 and an N“ type amorphous silicon film 5 to 200
`nanometer and 50 nanometer thickness, respectively. Then,
`the amorphous silicon fihns 4, 5 are patterned so as to be left
`in an island shape to a thin film transistor forming portion
`located in the central portion of the substrate 1. Apart of the
`amorphous silicon film 4 left in the island shape functions as
`a channel region of the thin film transistor. The interlayer
`insulating fihn 3 below the amorphous silicon film 4 left in
`the island shape functions as a gate insulating film of the thin
`film transistor. Successively, the interlayer insulation film 3
`is patterned to form through holes at connection positions
`between the lower layer metal wiring 2 and upper layer
`metal wiring in the terminal portion as shown in FIG. 3(b).
`In this embodiment,
`through holes are formed at four
`positions of the terminal portion to expose surfaces of the
`lower layer metal wiring 2, respectively.
`Then, another chromium (Cr) film as opaque conductive
`film is deposited to a film thickness of 140 nanometer so as
`to cover the interlayer insulation film 3 and the amorphous
`silicon films 4, 5 at the thin film transistor-forming portion,
`and so as to cover the interlayer insulation film 3 and the
`lower layer metal wiring 2 exposed through the contact
`holes 6 at the terminal portion. The film is patterned to form
`upper layer metal wirings 7—1 and 7—2 connected electrically
`with the lower layer metal wiring 2 in the contact holes 6 in
`the terminal portion, respectively.
`The upper layer metal wirings 7-1 and 7—2 are formed, as
`shown in FIG. 3(a), into island shapes, respectively, and are
`located over the lower layer wiring 2 in the terminal portion.
`That is, the upper layer metal wiring 7—1 and the upper layer
`metal wiring 7-2 are connected to the lower layer metal
`wiring 2 by way of different contact holes 6, respectively.
`However, they are separated from each other on the inter-
`layer insulation film 3 between the through holes 6. That is,
`in accordance with the present invention, a portion of the
`upper layer metal wiring is removed on the interlayer
`insulating film 3 between the through holes 6. In this
`patterning step, a drain electrode 7b and a source electrode
`
`CMI Exhibit 1005
`9
`
`CMI Exhibit 1005
`9
`
`

`

`5
`
`6
`
`5,636,329
`
`70 connected with the amorphous silicon fihns 4, 5,
`respectively, are formed in the thin film transistor—forming
`portion as shown in FIG. 3(a). Simultaneously, a data signal
`wiring 7a contiguous with the drain electrode 7b is formed
`to a display section other than the transistor—forming portion.
`Then, an Indium-Tin—Oxide (ITO) film as a transparent
`film is formed an exposed entire surfaces to a thickness of
`40 nanometer as the transparent conductive film 8 by a
`sputtering method The fihn is patterned to cover the inter—
`layer insulating film 3 and the upper layer metal wirings 7-1
`and 7—2 in the terminal portion and so as to form a pixel
`electrode 8a connected with the source electrode 7c in the
`display portion. Finally, a silicon nitride fihn of about 200
`nanometer thickness covering both the transistor-forming
`portion and the terminal portion is deposited by a plasma
`enhanced CVD method, to form a protective insulating film
`9. Further, an opening portion 14 is formed in the protective
`insulating film 9 as shown in FIG. 3(b). The openingportion
`14 exposes the transparent conductive film 8 at a portion
`formed on the surface of the interlayer insulating film 3 and
`the surface of the transparent conductive film 8 at a portion
`formed to the surface of the upper layer metal wiring 7-2 in
`the terminal portion. An opening portion is simultaneously
`formed in the protective insulating film 9 in the display
`portion for exposing the surface of the pixel electrode Sa.
`Through these processes, the manufacture of the active
`matrix substrate 8 is completed in this embodiment.
`Then. subsequent assembling steps for the liquid crystal
`display device will be explained with reference to FIG. 3(d).
`The active matrix substrate 100 manufactured as described
`above is fitted to a color filter substrate 200 while keeping
`a narrow gas therebetween. A liquid crystal panel is com-
`pleted by injecting and sealing liquid crystal material in the
`gap. Then, a tape—carrier package 300 as a driver IC for the
`liquid crystal panel is connected to the panel by using a
`connection member. In this embodiment, both of them are
`connected by using an anisotropic conductive film 10 as an
`example of the connection member.
`In the tape—carrier package 300, a driver IC die 32 is
`mounted on a flexible wiring substrate 31 comprising a
`plurality of copper foil wirings 31b formed on a flexible
`insulating film 31a and connected to each of a plurality of
`the copper foil wirings 31b, in which major portion of the IC
`die is covered with a potting resin as shown in FIG. 3(d).
`The tape-carrier package 300 is connected to the active
`matrix substrate 100 by at first provisionally bonding the
`anisotropic conductive fihn 10 on a terminal portion on the
`active matrix substrate 100 under selected temperature and
`pressure. The anisotropic conductive film 10 comprises
`conductive particles dispersed in a thermosetting resin. The
`provisional bonding is conducted, for example, by pressing
`the anisotropic conductive film 10 by way of a separator to
`the terminal portions of the active matrix substrate 100
`under the conditions at a temperature of 80° C., for a period
`of 3 sec. and at a pressure of 5 kg/cmz. After the provisional
`bonding, the separator adhered on the surface of the aniso-
`tropic conductive film 10 is peeled ofl. Further, the flexible
`wiring substrate 31 of the tape—carrier package 300 is
`disposed on the provisionally bonded anisotropic conductive
`film 10 and then press-bonded under heating to electrically
`connect the copper foil wirings 31b to the terminal portions
`of the liquid crystals, respectively. The bonding is conducted
`under the conditions, for example, at a temperature of 180°
`C., for a period of 18 sec. and under a pressure of 30 kg/cmZ.
`In this case, the resin of the anisotropic conductive film 10
`is fluidized to cover in an intimate contact with the surface
`
`of the terminal portion. The other connection portion of the
`
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`tape-carrier package 300 is connected to a rigid wiring
`substrate. For example, a power supply circuit is disposed to
`the rigid substrate for supplying a power source voltage to
`the tape—carrier package 300 and the active matrix substrate
`100. Further, the wiring substrate receives video signals
`decomposed into matrix signals in accordance with the
`display information of the liquid crystal panel and controls
`the driver IC 32 of the tape-carrier package 300.
`The tape—carrier package is connected to the terminal
`portion on the active matrix substrate 100 in this embodi-
`ment as shown specifically in the cross section of FIG. 3(e).
`In the terminal portion, the upper layer metal wiring 7 is
`eliminated at a portion not covered by the protective insu—
`lation film 9 or the anisotropic conductive film 10. In other
`words. in the terminal portion, the upper layer metal wiring
`7—1 is protected by double coverage with the transparent
`conductive film 8 and the protective insulation film 9, and
`the upper layer metal wiring 7-2 is protected at least by
`double coverage with the transparent conductive film 8 and
`the anisotropic conductive fihn 10. The upper layer wiring
`7—2 is further protected, locally, by coverage also with the
`protective insulation film 9. Accordingly, even if the trans-
`parent conductive fihn 8 in the terminal portion contains a
`defect, or even if it is used in a high humidity atmosphere,
`the upper layer metal wirings 7—1 and 7—2 are not exposed to
`the external air and protected against corrosion. In addition,
`the transparent conductive film 8 is formed directly on the
`surface of the interlayer insulation film 3 between the upper
`layer metal wiring 7-1 and the upper layer metal wiring 7-2
`and is exposed within the opening 14 of the protective
`insulation film 9. By applying a measuring probe to that part
`of the transparent conductive fihn 8, it can be checked
`whether the tape-carrier package 300 and the active matrix
`substrate 100 are electrically connected as desired or not,
`and it can be used as a checking terminal. That is, in this
`embodiment, it can be used as the checking terminal while
`preventing corrosion of the upper layer metal wirings 7—1
`and 7—2 in the terminal portion.
`If it is found upon checking that no suflicient electric
`connection is obtained between both of them, the tape-
`carrier package 300 connected by way of the anisotropic
`conductive film 10 in the terminal portion is peeled off from
`the active matrix substrate 100 and then bonded again as
`repairing operation. In the peeling step, not only the aniso-
`tropic conductive film 10 but also the underlying transparent
`conductive film 8 and the upper layer metal wiring 7—2 may
`also be peeled together sometimes frOm the active matrix
`substrate 100. In this embodiment, not only the upper layer
`metal wiring 7-2 but also the upper layer metal wiring 7—1
`are also formed and they are connected respectively by way
`of the through holes 6 to the lower layer metal wiring 2.
`Accordingly, if the copper foil wirings 31b of the tape-
`carrier package 300 and the transparent conductive film 8 in
`the terminal portion of the active matrix substrate 100 are
`connected again by a new anisotropic conductive film 10
`upon repairing operation, a conduction path connected by
`way of the upper layer metal wiring 7—1 to the lower layer
`metal wiring 2 can be ensured at least in the same manner
`as that before the repairing operation and a region usable as
`the checking terminal can be maintained.
`Further, in this embodiment, the upper layer metal wiring
`7-2 is connected by way of the through holes 6 at three
`positions to the lower layer metal wiring 2, while the upper
`layer metal wiring 7-1 connected by way of the transparent
`conductive film 8 to the upper layer metal wiring 7-2 is
`connected to the lower layer metal wiring 2 by way of the
`through hole 6 at one position, respectively. That is, the
`
`CMI Exhibit 1005
`10
`
`CMI Exhibit 1005
`10
`
`

`

`5,636,329
`
`7
`
`upper layer metal wirings 7—1 and 7—2 are electrically
`connected with the lower layer metal Wiring 2 by way of the
`through holes 6 at several positions. In the structure con-
`nected with the through holes disposed at several positions,
`the upper layer metal wiring is fastened to the lower layer
`metal wiring and can be made less peeling as compared with
`the structure connected by way of a single and a large
`diameter size through hole. Namely, also after the peeling
`step after the checking. the upper layer metal wiring 7—2 can
`be made less peeling from the active matrix substrate 100.
`Further, since the peripheral length for the opening portion
`of the through holes is made longer, the upper layer metal
`wiring is less disconnected in the through holes thereby
`enabling to provide more reliable connection between the
`upper layer metal wiring and the lower layer metal wiring.
`Further, since the transparent conductive film 8 and the
`lower layer metal wiring 2 are connected by way of the
`upper layer metal wirings 7-1 and 7—2. the upper layer metal
`wiring has a resistance value lower by about two digits as
`compared with ITO as the transparent conductive fihn 8, so
`that the resistance value can be lowered further. Further,
`since the upper layer metal wirings 7-1 and 7—2 are formed
`at the same time with the source electrode 70, the drain
`electrode 7b and the data signal Wiring 7a of the thin film
`transistor portion. no additional step is required for lowering
`the resistance value.
`
`Referring to FIG. 4(a) and FIG. 4(b), a second embodi-
`ment according to the present invention will be explained
`more specifically. FIG. 4(a) shows a terminal portion before
`forming an anisotropic conductive film 10. FIG. 4(b) shows
`a cross sectional view of a structure in which a flexible
`
`wiring substrate 31 is connected by way of the anisotropic
`conductive film 10. Identical portions with those in the first
`embodiment described above carry the same reference
`numerals for which duplicate explanation will be omitted. In
`this embodiment, an upper layer metal wiring 7 is electri-
`cally connected to a lower layer metal wiring 2 via three
`through holes 6. The upper layer metal wiring 7 is present
`only at a portion to which the anisotropic conductive film as
`an example of a connection member is press bonded. That is,
`the upper layer metal wiring 7 is protected at least by double
`coverage with a transparent conductive film 8 and the
`anisotropic conductive film 10 and further protected, locally,
`by coverage with a protective insulation film 9. The trans-
`parent conductive filrn 8 not covered with the anisotropic
`conductive film 10 and exposed through an apertured por-
`tion of the protective insulation film 9 can be used as a
`checking terminal. Also in this embodiment, the transparent
`conductive film 8 exposed through the apertured portion of
`the protective insulation film 9 is formed directly on the
`surface of the interlayer insulating film 3 under which the
`upper layer metal wiring 7 is not present in the same manner
`as in the first embodiment. Accordingly, even if the trans—
`parent conductive filrn 8 in the terminal portion contains a
`defect or it is used in a high humidity atmosphere, the metal
`wiring 7 is not exposed to the external atmospheric and can
`be protected against corrosion. In addition, by applying a
`measuring probe to the transparent conductive film at the
`portion exposed in the aperture, it can be checked as to
`whether the tape—carrier package 300 and the active matrix
`substrate 100 are connected electrically as desired and it can
`be used as the checking terminal. That is, also in this
`embodiment, it can be used as the checking terminal while
`preventing corrosion of the upper layer metal wiring 7 in the
`terminal portion. Further, according to this embodiment,
`since the metal wiring in the terminal portion near the
`display portion is protected by the metal wiring 9, the
`
`8
`transparent conductive film 9 and the interlayer insulation
`film 3,
`the corrosion resistance is further improved as
`compared with the first embodiment.
`Referring to FIG. 5(a) and FIG. 5(1)), a third embodiment
`according to the present invention will be explained more
`specifically. Identical portions with those of the first and the
`second embodiments carry the same reference numerals for
`which duplicate will be omitted. In the previous first and
`second embodiments, the transparent conductive layer 8 is
`formed to the upper layer of the upper layer metal wiring 7.
`In a case of manufacturing an active matrix substrate, a
`process of forming an upper layer metal wiring to the upper
`layer of the transparent conductive film is sometimes
`employed. In this case, the active matrix substrate is manu-
`factured through manufacturing steps of a gate wiring pat-
`terning step, an insulating film and an amorphous silicon
`film forming step, a through hole forming step, a pixel
`forming step, a drain wiring forming step, a channel etching
`step and a protective film forming step in this order. In this
`case, the upper layer metal wiring is also formed by pat-
`terning in the terminal portion in the drain wiring forming
`step. The transparent conductive film is also formed by
`patterning to the terminal portion in the pixel forming step.
`In this embodiment, the terminal portion comprises a dual
`layer film of the lower layer metal wiring 2—1 and the lower
`metal layer metal wiring 2—2, and the transparent conduc-
`tive film 8. That is, the island shape transparent conductive
`fihn 8 covers the lower layer metal wirings 2—1 and 2—2 as
`shown in FIG. 5(a), and the glass substrate 8 situating
`between the lower layer metal wirings, and electrically
`connects the lower layer metal wirings 2—1 and 2—2 sepa-
`rated from each other. The lower layer electrode wiring 2—1
`is protected by double coverage with the transparent con—
`ductive film 8 and the protective insulation film 9. The lower
`layer electrode wiring 2-—2 is protected by double coverage
`with the transparent conductive film 8 and the anisotropic
`conductive film 10 and also protected, locally, by coverage
`with the protective insulation film 9. Also in this
`embodiment, since the transparent conductive film 8
`exposed in the apertured portion of the protective insulation
`film 9 is formed directly on the surface of the glass substrate
`1, under which the metal wiring is not present, if the
`transparent conductive film 8 in the terminal portion con-
`tains a defect or it is used in a high humidity atmosphere, the
`lower layer metal wirings 2—1 and 2—2 are no