(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2004/003.6833 A1
`(43) Pub. Date:
`Feb. 26, 2004
`MOnzen
`
`US 2004.0036833A1
`
`(54)
`
`(75)
`
`(73)
`
`FLEXIBLE SUBSTRATE, LCD MODULE
`USING SAME, AND MANUFACTURING
`METHOD OF SAME
`
`Inventor: Masahiko Monzen, Fukuyama-shi (JP)
`Correspondence Address:
`NIXON & VANDERHYE, PC
`1100 N GLEBE ROAD
`8TH FLOOR
`ARLINGTON, VA 22201-4714 (US)
`Assignee: SHARP KABUSHIKI KAISHA, Osaka
`(JP)
`Appl. No.:
`Filed:
`
`10/643,992
`Aug. 20, 2003
`Foreign Application Priority Data
`
`(21)
`(22)
`(30)
`Aug. 23, 2002 (JP)...................................... 2002-244003
`
`Publication Classification
`
`(51) Int. Cl." ....................... G02F 1/1345; G02F 1/1333
`(52) U.S. Cl. .............................................................. 34.9/158
`
`(57)
`
`ABSTRACT
`
`A flexible substrate of the present invention is provided with
`a plurality of terminal blocks, each of which has a plurality
`of electrode terminals, there being two kinds of terminal
`pitches with which the plurality of electrode terminals are
`arrayed respectively in the plurality of terminal blocks, a
`compensation amount being Set for each terminal block in
`accordance with the terminal pitch thereof. With this
`arrangement, it is possible to connect the electrode terminals
`of the flexible Substrate with electrode terminals of an LCD
`without misalignment. That is, it is possible to match posi
`tions of the terminals of the flexible substrate with positions
`of the terminals of the LCD, so as to inhibit imperfect
`connection due to the misalignment caused after the thermal
`compression bonding.
`
`2: LCD SUBSTRATE
`
`4: UPPER
`SUBSTRATE
`
`17: ALIGNMENT
`
`
`
`
`
`
`
`
`
`
`
`16: ALIGNMENT
`MARK
`
`12: COMMON
`
`INPUT
`
`TERMINAL
`
`14: NON-FORMATION
`AREA
`
`15: NON-FORMATION
`AREA
`13: COMMON
`
`a INPUT
`1. A SELEC
`a
`1. 1. 1 AAAS
`
`d
`1. A
`
`
`11: SEGMENT INPUTTERMINAL
`
`TERMINAL
`
`
`
`
`
`
`
`
`
`W3
`
`3: LOWER
`SUBSTRATE
`
`22: COMMON 2
`23: COMMON
`21: SEGMENT --
`OUTPUT
`. Mini-
`OUTPUT 25. NON-FORMATION OUTPU
`YES 24 NFORMATION TERA. FORMATION REA
`
`26: ALIGNMENT
`
`27: ALIGNMENT
`
`Page 1 of 13
`
`Tianma Exhibit 1005
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`

`

`Patent Application Publication Feb. 26, 2004 Sheet 1 of 6
`
`US 2004/003.6833 A1
`
`FIG. 1
`
`2: LCD SUBSTRATE
`
`4: UPPER
`SUBSTRATE
`
`17: ALIGNMENT
`
`14: NON-FORMATION
`AREA
`
`15: NON-FORMATION
`AREA
`13: COMMON
`a INPUT
`TERMINAL
`
`
`
`11: SEGMENT INPUTTERMINAL
`
`1 EASAt 1 E
`
`
`
`16: ALIGNMENT
`MARK
`
`12: COMMON
`INPUT
`TERMINAL
`
`
`
`
`
`
`
`
`
`
`
`
`
`W2
`
`W1
`
`W3
`
`3: LOWER
`SUBSTRATE
`
`22: COMMON 2
`OUTPUT
`... Mr.N-
`
`YES 24 NFORMATION TERA 25 NSFORMATION TEL
`
`21: SEGMENT
`OUTPUT of Minn-
`
`23: COMMON
`OUTPUT
`
`26: ALIGNMENT
`MARK
`
`1: FLEXIBLE SUBSTRATE
`
`27: ALGNMENT
`MARK
`
`Page 2 of 13
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`

`

`ication Publication
`
`Feb. 26, 2004 Sheet 2 of 6
`
`US 2004/003.6833 A1
`
`
`
`
`
`88
`
`Page 3 of 13
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`

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`Patent Application Publication Feb. 26, 2004 Sheet 3 of 6
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`US 2004/003.6833 A1
`
`FIG. 3
`
`
`
`Page 4 of 13
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`

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`Patent Application Publication Feb. 26, 2004 Sheet 4 of 6
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`US 2004/003.6833 A1
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`FIG. 4
`
`
`
`A 2 V L
`
`Y 1.
`
`M
`
`I
`
`2
`
`2 Y 1. A. 1 . C
`
`2
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`Page 5 of 13
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`

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`Patent Application Publication Feb. 26, 2004 Sheet 5 of 6
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`US 2004/003.6833 A1
`
`FIG. 5 (a)
`
`CO
`CO2
`CO3
`CO4
`COM5
`CO6
`
`UPPER GLASS
`
`LOWER GLASS
`
`FIG. 5 (c)
`COF PROVIDED WITH
`A LIQUID CRYSTAL DRIVER
`FOR SEGMENT ELECTRODES
`
`
`
`
`
`POLARIZER
`
`UPPER GLASS
`(IN WHICH COMMONELECTRODES
`ARE PROVIDED)
`COF PROVIDED WITH
`ALIQUID CRYSTALDRIVER
`FOR COMMON ELECTRODES
`
`LOWER GLASS
`(IN WHICH SEGMENTELECTRODES
`ARE PROVIDED)
`
`Page 6 of 13
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`

`

`Patent Application Publication Feb. 26, 2004 Sheet 6 of 6
`
`US 2004/003.6833 A1
`
`FIG. 6 (a)
`
`COMINPUTTERMINALS TO 3
`
`SEGINPUTTERMINAL
`
`COMINPUTTERMINALS 4TO 6
`
`LOWER GLASS
`
`FIG. 6 (c)
`
`UPPER GLASS
`
`
`
`POLARIZER
`
`LOWER GLASS
`
`COF PROVIDED WITH
`A LIQUID CRYSTAL DRIVER
`FORSEGMENT AND COMMONELECTRODES
`
`Page 7 of 13
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`

`

`US 2004/0036833 A1
`
`Feb. 26, 2004
`
`FLEXIBLE SUBSTRATE, LCD MODULE USING
`SAME, AND MANUFACTURING METHOD OF
`SAME
`
`FIELD OF THE INVENTION
`0001) The present invention relates to (a) a flexible
`Substrate including a plurality of terminal blocks, each of
`which is provided with a plurality of electrode terminals, the
`plurality of terminal blocks arranged with at least two kinds
`of terminal pitches, (b) an LCD module using the same, and
`(c) a manufacturing method of the same.
`
`BACKGROUND OF THE INVENTION
`0002 Today, LCDs (Liquid Crystal Display apparatus)
`has become a display apparatus typically chosen for dis
`playing information. For example, the use of LCDS is
`inevitable in portable information apparatuses, Such as por
`table telephones, PHS (Personal Handy-phone System)
`apparatus, and the like. Parts to be used in those apparatuses
`should have a light weight and a compact size. To an LCD
`Substrate to be integrated in those apparatus, a flexible
`substrate (COF (Chip On Flexible printed circuit board),
`TCP (Tape Carrier Package), TAB (Tape Automated Bond
`ing), FPC (Flexible Printed Circuit), and the like) is con
`nected via an anisotropic conductive material by thermal
`compression bonding. The flexible Substrate has (a) equally
`pitched terminals (terminals arrayed with constant pitch) on
`one edge, and (b) a liquid crystal driver connected to the
`terminals. With this arrangement, the LCD Substrate is
`driven by the liquid crystal driver.
`0003. In this case, the LCD substrate made of glass and
`the flexible Substrate are different in terms of coefficient of
`thermal expansion. Thus, the LCD Substrate or the flexible
`Substrate should have a design in which elongation com
`pensation is taken into consideration. In general, arts in
`which such compensation is carried out for the flexible
`Substrate is adopted.
`0004 For example, Japanese Publication of Unexamined
`Patent Application “Tokukaihei No. 4-289824” (published
`on Oct. 14, 1992) is one of such arts. In this publication,
`positional misalignment between electrode terminals of an
`LCD Substrate and lead terminals of a flexible Substrate is
`avoided by having terminal pitches that are Set in consider
`ation of elongation of a base film of the flexible substrate, the
`elongation caused during a thermal compression bonding
`Step.
`0005 Moreover, for example, Japanese Publication of
`Unexamined Patent Application “Tokukai No. 2000
`3.12070" (published on Nov. 7, 2000) is another one of such
`arts. In this publication, either outgoing electrode terminals
`of an LCD substrate or output electrode terminals of a
`flexible Substrate have constant pitch, whereas the others are
`So arranged as to have terminal pitches compensated in
`accordance with coefficient of thermal expansion of the
`flexible substrate, so that they are arrayed with small termi
`nal pitches in middle portion of a terminal Section, and the
`terminals nearer to edges of the Substrate have wider termi
`nal pitches. In this way, imperfect connection is reduced.
`0006 The related arts of the publications are applicable
`to an TFT (Thin Film Transistor)-LCD, where the terminal
`pitches are constant. However, in case of an STN (Super
`
`Twisted Nematic)-LCD that is subjected to COMMON
`transfer, it is necessary that the COMMON transfer be
`performed so as to provide SEGMENT terminals and COM
`MON terminals on a glass side of one of Substrates, and
`terminal widths of those terminals be varied. It is a problem
`that the related arts are not applicable in this case.
`0007 Referring to FIGS. 5(a) to 5(c), and 6(a) to 6(c), the
`normal transfer is explained below. FIGS. 5(a) to 5(c) are
`ViewS explaining an LCD module that is not Subjected to the
`normal transfer. An upper glass substrate shown in FIG. 5(a)
`and a lower glass substrate shown in FIG. 5(b) are bonded
`together together, and then liquid crystal is Sealed therebe
`tween. ACOF, which is provided with a driver IC (integrated
`circuit) for driving COMMON electrodes, is connected on
`the upper glass Substrate by the thermal compression bond
`ing. Whereas, a COF which is provided with a driver IC for
`driving SEGMENT electrodes, is connected on the lower
`glass Substrate by the thermal compression bonding. Hereby,
`an LCD module shown in FIG. 5(c) is prepared.
`0008. On the other hand, FIGS. 6(a) to 6(c) are views
`explaining an LCD module that is subjected to the COM
`MON transfer. As shown in FIG. 6(a), an upper glass
`Substrate and a lower glass Substrate, which are shown in
`FIG. 6(b), are connected together, the upper glass Substrate
`provided with COMMON electrodes which outgo in the
`same direction as SEGMENT electrodes of the lower Sub
`Strate. Then, liquid crystal is Sealed therebetween. Hereby,
`parts A and B of the upper Substrate and corresponding parts
`A and B of the lower Substrate are electrically connected, So
`that COMMON electrodes are formed on the lower glass
`substrate. Thereafter, a COF including a driver IC for
`driving the COMMON electrodes is connected onto the
`upper glass Substrate by the thermal compression bonding,
`whereas a COF including a driver IC for driving the SEG
`MENT electrodes is connected onto the lower Substrate by
`the thermal compression bonding. In this case, an LCD
`module as shown in FIG. 6(c) is prepared.
`0009. In case of such an LCD that is subjected to the
`COMMON transfer, it is necessary that the SEGMENT
`terminals and the COMMON electrodes (terminals) be pro
`Vided on a glass Side of one of Substrates, and widths of the
`terminals be varied, as described above. Especially, if ter
`minal pitches are less than 100 um (narrow pitches), the
`flexible Substrate elongates at different elongation rates in
`parts having different pitches. Because of this, it is difficult
`to connect the flexible substrate to the LCD without causing
`misalignment.
`
`SUMMARY OF THE INVENTION
`0010. In view of the aforementioned problems, the
`present invention has an object to provide (a) a flexible
`Substrate whose electrode terminals, which have different
`pitches, can be connected with their counterpart electrode
`terminals without causing imperfect connection after ther
`mal compression bonding, (b) an LCD module using the
`Same, and (c) a manufacturing method of the same.
`0011. In order to attain the aforementioned object, a
`flexible substrate of the present invention is provided with a
`plurality of terminal blocks, each of which has a plurality of
`electrode terminals, there being two kinds of terminal
`pitches with which the plurality of electrode terminals are
`arrayed respectively in the plurality of terminal blocks, a
`
`Page 8 of 13
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`US 2004/0036833 A1
`
`Feb. 26, 2004
`
`post-thermal-compression-bonding elongation compensa
`tion amount (an amount of compression for elongation that
`is caused after thermal compression bonding) being set for
`each terminal block in accordance with the terminal pitch
`thereof.
`0012. With this arrangement, the flexible substrate such
`as a TCP, a COF, an FPC and the like is connected with its
`counterparts (such as an LCD) with which the flexible
`Substrate is to be connected. In connecting, the plurality of
`terminal blocks provided to the flexible substrate are con
`nected with the corresponding terminal blocks of the coun
`terparts, by the thermal compression bonding.
`0013 Incidentally, in case of the flexible substrate in
`which at least one terminal block has a different terminal
`pitches of electrode terminals from that of the other terminal
`blocks, if the terminal pitches are Small (less than 100 um),
`the conventional elongation compensation cannot attain
`Such good alignment between the flexible Substrate and its
`counterpart (such as an LCD) that all of the terminal blocks
`are well connected with their counterpart terminal blockS
`respectively.
`0.014 With this arrangement, it is possible to connect the
`electrode terminals of the flexible Substrate with the elec
`trode terminals of its counterpart (such as an LCD) with
`respect to all of the terminal block (that is, all of the terminal
`blocks are well connected with their counterpart terminal
`blocks respectively), because the compensation amounts are
`Set in accordance with the terminal pitches.
`0.015 Moreover, an LCD module of the present invention
`is So arranged as to include any one of the flexible Substrate
`described above, in order to attain the aforementioned
`object.
`0016. With this arrangement, in an LCD module prepared
`by bonding a flexible substrate (such as a TCP, a COF, and
`PC) onto a Substrate (Such as glass) by using an anisotropic
`conductive material or the like, it is possible to attain good
`connection of the electrode terminals for all the terminal
`blocks without misalignment, by using the one of the
`flexible substrates described above. Specifically, when this
`arrangement is adopted in Such an LCD and the one of the
`flexible Substrates described above is used, for all the
`terminal blocks, the electrode terminals of the flexible
`Substrate, and the electrode terminals of the counterpart with
`which the flexible substrate (such as an LCD) is connected,
`are connected without misalignment. In addition, it is pos
`Sible to inhibit imperfect connection due to misalignment
`caused by the thermal compression bonding.
`0.017. Furthermore, in order to attain the aforementioned
`object, a method of the present invention of manufacturing
`a liquid crystal display module in which a liquid crystal
`Substrate is connected with a flexible Substrate including a
`plurality of terminal blocks, each of the plurality of terminal
`blocks having a plurality of electrode terminals, and the
`plurality of terminal blocks including a first terminal block
`and a Second terminal blocks having different terminal
`pitches, the method including the steps of: (i) performing
`compression bonding of a test flexible Substrate made of the
`Same material as the flexible Substrate and including a
`plurality of terminal blocks having a predetermined terminal
`pitch; (ii) measuring an amount of a size change in the
`terminal pitch in each terminal block, the Size change caused
`
`by the compression bonding; (iii) determining a compensa
`tion amount of the terminal pitch of each terminal block,
`based on the amount of the size change thereof; (iv) setting
`terminal pitches of the flexible Substrate by compensating
`the terminal pitches of the test flexible substrate by the
`compensation amount, (v) manufacturing the flexible Sub
`strate so that the flexible Substrate has the thus set terminal
`pitches; and (vi) performing thermal compressing bonding
`of the flexible Substrate so as to connect the flexible Substrate
`with the liquid crystal display apparatus, wherein, in the Step
`of determining, the compensation amount is determined for
`each terminal block having in accordance with the terminal
`pitch thereof.
`0018. According to this method, in an LCD module
`prepared by bonding a flexible substrate (such as a TCP, a
`COF, and an FPC) onto a substrate (such as glass) by using
`an anisotropic conductive material or the like, it is possible
`to attain good connection of the electrode terminals for all
`the terminal blocks without misalignment. Specifically,
`when this arrangement is adopted in Such an LCD, for all the
`terminal blocks, the electrode terminals of the flexible
`Substrate, and the electrode terminals of the counterpart with
`which the flexible substrate (such as an LCD) is connected,
`are connected without misalignment. In addition, it is pos
`Sible to inhibit imperfect connection due to misalignment
`caused by the thermal compression bonding.
`0019 For a fuller understanding of the nature and advan
`tages of the invention, reference Should be made to the
`ensuing detailed description taken in conjunction with the
`accompanying drawings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`0020 FIG. 1 is a plan view illustrating connecting por
`tions of the flexible Substrate and of an LCD Substrate of one
`embodiment of the present invention. With the connecting
`portions, the flexible substrate and the LCD Substrate are to
`be connected.
`0021 FIG. 2 is a side view illustrating how the flexible
`substrate and the LCD substrate are connected by the
`thermal compression bonding.
`0022 FIG. 3 is a perspective view of an LCD module
`prepared in the thermal compression bonding mentioned
`above.
`0023 FIG. 4 is a plan view illustrating connecting por
`tions of the flexible Substrate and of an LCD Substrate of
`another embodiment of the present invention. With the
`connecting portions, the flexible substrate and the LCD
`Substrate are to be connected.
`0024 FIGS. 5(a) to 5(c) are views explaining an LCD
`module that is not subjected to COMMON transfer.
`0.025 FIGS. 6(a) to 6(c) are views explaining an LCD
`module that is subjected to the COMMON transfer.
`
`DESCRIPTION OF THE EMBODIMENTS
`0026 Described below is one embodiment of the present
`invention, with reference to FIGS. 1 to 3.
`0027 FIG. 1 is a plan view illustrating connecting por
`tions of the flexible Substrate 1 and of an LCD Substrate 2 of
`one embodiment of the present invention. With the connect
`
`Page 9 of 13
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`US 2004/0036833 A1
`
`Feb. 26, 2004
`
`ing portions, the flexible substrate 1 and the LCD substrate
`2 are to be connected. FIG. 1 explains how terminal pitches
`are compensated according to the present invention. This
`compensation may be carried out for one of a flexible
`substrate 1 and an LCD substrate 2. However, the compen
`sation is carried out for the flexible Substrate 1 in the
`following explanation.
`0028. The LCD substrate 2 is structured as follows: an
`upper Substrate 4 is connected on a lower Substrate 3, the
`upper substrate 4 and the lower Substrate 3 being bonded;
`STN liquid crystal is hermetically sealed between the Sub
`strates 3 and 4; a plurality of SEGMENT input terminals 11
`(electrode terminals) are provided in a middle portion of an
`edge of the lower Substrate 3, the middle portion being not
`covered by the upper substrate 4. The plurality of SEG
`MENT input terminals 11 form a terminal block (first
`terminal block); near both side portions of the flexible
`substrate 1, COMMON input terminals 12 and 13 (electrode
`terminals) are respectively provided by COMMON transfer
`as described above. The COMMON input terminals 12 and
`13 constitute terminal blocks (second terminal blocks),
`respectively. The SEGMENT input terminals 11 have com
`paratively fine (very narrow) terminal pitches, whereas the
`COMMON input terminals 12 and 13 have comparatively
`broad terminal pitches. In other word, the terminal pitch of
`the first terminal block is narrower than the terminal pitch of
`the second terminal blocks. On both sides of each SEG
`MENT input terminal 11, that is, (a) between the respective
`SEGMENT input terminals 11 and the respective COM
`MON input terminals 12, and (b) between the respective
`SEGMENT input terminals 11 and the respective COM
`MON input terminals 13, non-formation areas 14 and 15 in
`which no electrode terminal is provided, are formed. More
`over, near both side portions of the lower substrate 3,
`alignment marks 16 and 17 are respectively provided. The
`alignment markS 16 and 17 are for positional alignment of
`the flexible substrate 1 in bonding the flexible substrate 1
`with the LCD Substrate 2.
`0029. Meanwhile, the flexible substrate 1 is composed of
`a COF, a TCP, a TAB, an FPC, or the like. On an edge of a
`black surface of the flexible substrate 1, SEGMENT output
`terminals 21 are provided in a middle portion of the edge of
`the back surface, the SEGMENT output terminals 21 respec
`tively corresponding to the SEGMENT input terminals 11.
`Near the side portions of the flexible substrate, COMMON
`output terminals 22 and 23 are respectively provided, the
`COMMON output terminals 22 and 23 respectively corre
`sponding to the common input terminals 12 and 23. On both
`sides of the SEGMENT output terminals 21, non-formation
`areas 24 and 25, in which no electrode terminal is provided,
`are formed. Moreover, on both side portions of the flexible
`Substrate 1, alignment markS 26 and 27 are provided respec
`tively. In this way, the flexible substrate 1 corresponds to the
`lower Substrate 3.
`0030) The flexible substrate 1 and the LCD substrates 2
`having the above arrangement are, as shown in FIG. 2,
`connected together So that the alignment markS 16 and 17
`respectively match with the alignment markS 26 and 27, and
`then Subjected to temporary compression bonding So as to be
`temporally connected together. After that, the thus tempo
`rally connected flexible Substrate 1 and the LCD substrate
`are Subjected to compression bonding by using a tool 32 that
`is set at a temperature in a range of 200 C. to 250 C. In this
`
`way, the output terminals 21, 22, and 23 of the flexible
`Substrate 1 are electrically connected with the input termi
`nals 11, 12, and 13 of the LCD substrate 2, respectively.
`Here, a back surface of the LCD substrate 2 is supported by
`a backup 33. A bonding cushioning material 34 is provided
`at a tip of the tool 32. Hereby, an LCD module 41 is
`prepared.
`0031. The thus prepared LCD module 41 is as shown in
`FIG. 3, in case of the LCD module 41 is used for a small
`Screen for a portable telephone and the like. Here, one
`flexible Substrate 1 is used for the LCD Substrate 2. The
`flexible substrate 1 is provided with a driver IC 42 and an
`electrode terminal 43. The electrode terminal 43 is located
`on an edge opposite to the edge on which the output
`terminals 21 to 23 are located. A video Signal and power are
`supplied to the electrode terminal 43.
`0032) If the terminal pitches of the terminals 11, 12, 13,
`21, 22, and 23 (see FIG.1) are less than 100 um, that is, they
`are narrow pitches (fine pitches), elongation rates (coeffi
`cient of thermal expansion) of the flexible substrate are
`different in parts having different terminal pitches. There
`fore, in this case, it is difficult to connect the flexible
`substrate 1 to the LCD Substrate 2 by the thermal compres
`Sion bonding without misalignment. Thus, in the present
`invention, the terminal pitches of the flexible substrate are
`compensated as follows, in order to prevent imperfect con
`nection (failure in boding) due to the misalignment.
`0033 Even for parts having the same output pitches,
`different materials of the flexible substrate 1 have different
`coefficients of thermal expansion. Thus, a test is carried out
`by using a substrate (test flexible substrate) made of the
`same material as the flexible Substrate 1 that is used for an
`actual product. The test flexible substrate is made of the
`same material as the flexible substrate 1 and provided with
`a plurality of terminal blocks as the flexible substrate 1 does,
`the terminal blocks being formed with a predetermined
`terminal pitch). The test flexible substrate is subjected to
`compression bonding (thermal compression bonding). AS to
`(a) the plurality of terminal blocks of the output terminals
`21, 22, and 23, and (b) the non-formation areas 24 and 25,
`amounts of change (change amount) in widths W1 to W5 are
`measured, the change caused by the compression bonding.
`Compensation rate in each area is determined from differ
`ences (change amounts in widths) between the widths mea
`Sured before the compression bonding and those measured
`after the compression bonding. Note that in the measure
`ment, for each of the terminals blocks of the output terminals
`21, 22, and 23, a distance between both outmost terminals (a
`change amount in the distance) are measured for the sake of
`high measurement accuracy.
`0034 Based on the thus determined compensation rates
`(coefficient of thermal expansion) and a number of the
`terminals (=a distance from a midpoint of an edge of the
`substrate), the flexible substrate 1 in which the terminals 21,
`22, and 23 are formed is produced, the terminals 21, 22, and
`23 having terminal pitches compensated orderly (that are
`compensated by their own compensation amounts. The
`compensation amounts of the output terminals 21, 22, and
`23 are greater in this order. In other words, the terminal
`pitches of the test flexible Substrate are compensated based
`the compensation rates, So as to find out Setting of the
`terminal pitches of the flexible substrate that is to be used in
`
`Page 10 of 13
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`US 2004/0036833 A1
`
`Feb. 26, 2004
`
`an actual product. Then, the flexible Substrate is manufac
`tured with the terminal pitches thus Set. In finding out the
`Setting of the terminal pitches, Suitable compensation
`amounts are determined for the respective terminals. For
`example, in case one flexible Substrate 1 having a thickneSS
`of 40 um is used, a terminal block to have a 80 um pitch is
`compensated by having a pre-compression terminal pitch of
`99.85% of 80 um (so that the terminal block has a terminal
`pitch of 80 um after the thermal compression bonding). For
`terminal block to have a 70 um pitch in the flexible substrate
`1 having a thickness of 40 tim, the terminal block is
`compensated by having a pre-compression terminal pitch of
`99.89% of 70 um (so that the terminal block has a terminal
`pitch of 70 um after the thermal compression bonding).
`0035. By arranged as such, even if the terminals 11, 12,
`13, 21, 22, and 23 having different terminal pitches are used,
`and the flexible Substrate 1 is expanded, (a) positions of the
`output terminals 21, 22, and 23 on the flexible substrate 1
`and (b) positions of the corresponding input terminals 11,
`12, and 13 on the LCD Substrate 2, are connected respec
`tively without causing misalignment after the thermal com
`pression bonding. Thereafter, the flexible substrate thus
`manufactured is connected to the LCD Substrate by the
`thermal compression bonding.
`0.036 Moreover, as described above, the present inven
`tion is so arranged that the SEGMENT terminals 11 and 21
`having the fine pitch are provided in the middle portion, and
`the COMMON terminals 12, 13, 22, and 23 having com
`paratively broader terminal pitches are respectively pro
`vided near the side portions of the flexible Substrate 1. For
`the SEGMENT terminals 11 and 21, a half of the terminal
`pitch, that is, 50% of the SEGMENT terminals 11 and 21 is
`an actual terminal portion, whereas the other 50% is a Space
`portion, as normally designed. On the other hand, the
`COMMON terminals 12, 13, 22, and 23 have a narrower
`actual terminal portion. For example, 45% of the terminal
`pitch of the COMMON terminals 12, 13, 22, and 23, is an
`actual terminal portion whereas the rest 55% is a Space
`portion. That is, a ratio between a terminal width and the
`terminal pitch (a terminal width/terminal pitch ratio) of the
`SEGMENT terminals 11 and 12 in the middle portion is
`greater than that ratio of the COMMON terminals 12, 13, 22
`and 23 respectively located in the Side portions.
`0037. Therefore, as to the SEGMENT terminals 11 and
`12 having the fine terminal pitch, this arrangement makes it
`possible to alleviate misalignment in the vicinity of the
`middle portion of the flexible substrate 1, the misalignment
`caused by the thermal compression bonding. AS to the
`COMMON terminals 12, 13, 22, and 23, having the com
`paratively broad width, even if misalignment is caused by
`the thermal compression bonding, there is a high possibility
`that the positions of the common output terminals 22 and 23
`of the flexible Substrate 1 locate within the width of the
`common input terminals 12 and 13 of the LCD substrate 2,
`because the ratio between the terminal width and the termi
`nal pitch (a terminal width/terminal pitch ratio) of the
`COMMON terminals 12, 13, 22, and 23 (of the vicinity of
`the side portions) is Smaller than that ratio of the terminals
`located in the middle portion. Thus, it is possible to further
`inhibit the imperfect connection.
`0038. By arranging the COMMON terminals and the
`SEGMENT terminals as described above, it is possible to
`absorb accumulated elongation, and misalignment.
`
`0039) Described below is another embodiment of the
`present invention, referring to FIG. 4.
`0040 FIG. 4 is a plan view illustrating connecting por
`tions of the flexible Substrate 51 and of an LCD Substrate 2
`of another embodiment of the present invention, at which the
`flexible Substrate 1 and the LCD Substrate 2 are to be
`connected. The LCD Substrate 2 has been described above.
`In the flexile substrate 51, sections similar and correspond
`ing to the sections of the flexible substrate 1 are labeled in
`the same manner, and their explanation is omitted here. It
`should be noted that the flexible substrate 51 is provided
`with a plurality of dummy terminals 54 and 55 in non
`formation areas 24 and 25, respectively.
`0041. The flexible substrate 51 may be so arranged that
`the dummy terminals 54 and 55 are formed with the same
`terminal pitch as the SEGMENT output terminals 21, but
`may be formed with the same terminal pitch as the COM
`MON terminals 22 and 23. Moreover, the flexible Substrate
`51 may be so arranged that the dummy terminals 54 and 55
`are formed with an arbitrary terminal pitch. In this case,
`compensation rates (coefficient of thermal expansion) of
`each of the dummy terminals 54 and 55 should be worked
`out, from thermal compression bonding-caused changes in
`widths W54 and W55 of portions of the dummy terminals 54
`and 55. On the other hand, if it is so arranged that the dummy
`terminals 54 and 55 have the same terminal pitch as the
`SEGMENT output terminals 21, or as the COMMON output
`terminals 22 and 23, it is possible to measure the widths
`W54 and W55 (in one batch) at the same time when the
`widths W1, W2, and W3 are measured. This attains more
`accurate measurement.
`0042 Moreover, the more electrode terminal portions,
`the Smaller electrode-to-electrode areas in the non-formation
`areas 24 and 25. This makes it possible to reduce unevenneSS
`in a post-thermal-compression-bonding elongation amount
`(an amount of elongation caused after the thermal compres
`Sion bonding) in the non-formation areas 24 and 25. As a
`result, in all terminal blocks, it is possible to connect the
`electrode terminals of the flexible Substrate 51 with the
`electrode terminals of the LCD substrate 2 without misalign
`ment. If it is So arranged that (a) the elongation of the
`flexible substrate is small, (b) unevenness in the coefficient
`of the thermal expansion is Small, and (c) the greater
`terminal pitch the Smaller terminal width/terminal pitch
`ratio, it is preferable that the terminal pitches of the dummy
`terminals 54 and 55 are the same as the SEGMENT output
`terminal 21 having the Small terminal pitch.
`0043. By arranging such that the dummy electrodes 54
`and 55 are provided in the non-formation areas 24 and 25
`which essentially does not require electrode terminals
`therein, it is possible to reduce the amounts of the post
`thermal-compression-bonding elongation and reduce the
`unevenneSS in the amount of the post-thermal-compression
`bonding elongation. Therefore, it is possible to reduce an
`accumulated expansion amount that is accumulated in an
`area between the common output terminals 22 and 23 that
`are located outward with respect to the dummy electrodes 54
`and 55. Further, it is possible to improve bonding strength.
`0044) It should be noted that the above explanation is
`based on the case where there are three terminal blocks, two
`of which have the same terminal pitches, and the rest of
`which has a different terminal pitch. However, the present
`
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`US 2004/0036833 A1
`
`Feb. 26, 2004
`
`invention is not limited to this. The present invention is also
`applicable in a case where each terminal block has a
`different pitch.
`0.045. A flexible substrate of the present invention is, as
`described above, provided with a plurality of terminal
`blocks, each of which has a plurality of electrode terminals,
`there being two kinds of terminal pitches with which the
`plurality of electrode terminals are arrayed respectively in
`the plurality of terminal blocks, a post-thermal-compres
`Sion-bonding elongation compensation amount (an amount
`of the compensation of the terminal pitch with respect to the
`elongation caused after the thermal compression bonding)
`being Set for each terminal block in accordance with the
`terminal pitch thereof.
`0046) With this arrangement, the flexible substrate such
`as a TCP, a COF, an FPC and the like is connected with its
`counterparts (such as an LCD) with which the flexible
`Substrate is to be connected. In connecting, the plurality of
`terminal blocks provided to the flexible substrate are con
`nected with the corresponding termina