Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 1 of 12 Page ID #:364
`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 1 of 12 Page ID #:364
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`
`EXHIBIT 5
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`EXHIBIT 5
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`
`
`
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`COMPLAINT-299
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`COMPLAINT-299
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`

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`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 2 of 12 Page ID #:365
`Case8=20-CV-00490 ”we“ 1'5 FilllllllllllllllllllIllll’llll'lllflalllllIllllIllll’llllllllllfilll‘llllllll
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`USOO8446556B2
`
`(12) United States Patent
`US 8,446,556 B2
`(10) Patent N0.:
`Kawamura et al.
`
`(45) Date of Patent: May 21, 2013
`
`(54)
`
`(75)
`
`FLEXIBLE PRINTED CIRCUIT AND
`ELECTRIC CIRCUIT STRUCTURE
`
`Inventors: Teruo Kawamura, Osaka (JP); Toshio
`Etoh, Osaka (JP)
`
`(73)
`
`Assignee: Sharp Kabushiki Kaisha, Osaka (JP)
`
`(*)
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 265 days.
`
`(21)
`
`Appl. N0.:
`
`13/000,615
`
`(22)
`
`PCT Filed:
`
`Jun. 24, 2009
`
`(86)
`
`(87)
`
`(65)
`
`(30)
`
`(51)
`
`(52)
`
`(58)
`
`PCT No.:
`
`PCT/JP2009/061505
`
`§371(CX1)
`(2), (4) Date:
`
`Dec. 21, 2010
`
`PCT Pub. No.: W02010/004875
`
`PCT Pub. Date: Jan. 14, 2010
`
`Prior Publication Data
`
`US 2011/0102729 A1
`
`May 5, 2011
`
`Foreign Application Priority Data
`
`Jul. 8, 2008
`
`(JP) ................................. 2008-178299
`
`(2006.01)
`
`Int. Cl.
`G02F 1/1345
`US. Cl.
`USPC ............ 349/149; 349/150; 349/151; 349/152
`Field of Classification Search .................. 349/149,
`349/150,151,152
`See application file for complete search history.
`
`IIIII
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`................... 349/147
`3/2003 Anno et a1.
`6,535,261 B1 *
`8,279,612 B2 * 10/2012 Murakami et a1.
`............ 361/749
`FOREIGN PATENT DOCUMENTS
`2-9469
`*
`1/1990
`1990-9469 U
`1/1990
`H4-28437 U
`3/1992
`2007-87999
`4/2007
`
`*
`
`JP
`JP
`JP
`JP
`
`OTHER PUBLICATIONS
`
`International Search Report (ISR) issued in PCT/JP2009/061505
`(parent application) mailed in Jul. 2009 for Examiner consideration.
`
`* cited by examiner
`
`Primary Examiner 7 Mike Qi
`(74) Attorney, Agent, or Firm 7 Chen Yoshimura LLP
`
`(57)
`
`ABSTRACT
`
`Provided are a flexible printed circuit that reduces the chance
`of the occurrence of short-circuit failures caused by swarf
`generated from punching out flexible printed circuit, and an
`electric circuit structure having this flexible printed circuit
`and an electric circuit substrate to which the flexible printed
`circuit is connected. A flexible printed circuit (100) has a
`wiring pattern (2) formed on the flexible base film (1). The
`flexible printed circuit (100) is individually punched out to be
`separated in a condition where the wiring pattern (2) is dis-
`posed on the base film (1), and the wiring pattern (2) has a
`narrowed portion (20) near the edge of the base film (1).
`
`6 Claims, 5 Drawing Sheets
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`
`
`T1
`rn‘;
`3H7
`’i'i‘
`er‘srfi
`
`a
`1W74
`‘1
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`COMPLAINT-3 00
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`COMPLAINT-300
`
`

`

`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 3 of 12 Page ID #:366
`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 3 of 12 Page ID #:366
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`U.S. Patent
`
`May 21, 2013
`
`Sheet 1 of 5
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`US 8,446,556 B2
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`FIG. 1
`
`
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`
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`
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`COMPLAINT-3 01
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`COMPLAINT-301
`
`

`

`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 4 of 12 Page ID #:367
`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 4 of 12 Page ID #:367
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`US. Patent
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`May 21, 2013
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`Sheet 2 of5
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`US 8,446,556 B2
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`FIG. 2
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`
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`COMPLAINT-3 02
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`COMPLAINT-302
`
`

`

`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 5 of 12 Page ID #:368
`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 5 of 12 Page ID #:368
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`US. Patent
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`May 21, 2013
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`Sheet 3 of5
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`US 8,446,556 B2
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`FIG. 3
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`
`
`1H."."'
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`Cflmmmflmmmnnnflnnnannuunati:1
`
`fl1:!UDEUEDDE’IE’EHGG1U
`
`mu:
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`
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`COMPLAINT-3 03
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`COMPLAINT-303
`
`

`

`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 6 of 12 Page ID #:369
`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 6 of 12 Page ID #:369
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`US. Patent
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`May 21, 2013
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`Sheet 4 of5
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`US 8,446,556 B2
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`FIG. 4
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`
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`COMPLAINT-3 04
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`COMPLAINT-304
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`

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`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 7 of 12 Page ID #:370
`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 7 of 12 Page ID #:370
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`US. Patent
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`May 21, 2013
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`Sheet 5 of5
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`US 8,446,556 B2
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`
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`COMPLAINT-3 05
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`COMPLAINT-305
`
`

`

`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 8 of 12 Page ID #:371
`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 8 of 12 Page ID #:371
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`US 8,446,556 B2
`
`1
`FLEXIBLE PRINTED CIRCUIT AND
`ELECTRIC CIRCUIT STRUCTURE
`
`TECHNICAL FIELD
`
`The present invention relates to flexible printed circuits
`having wiring patterns formed on a base film, which flexible
`printed circuits are punched out to be individually separated,
`along with the wiring patterns, and an electric circuit structure
`comprising the flexible printed circuits and an electric circuit
`substrate to which the flexible printed circuits are connected.
`More particularly, the present invention relates to a flexible
`printed circuit and an electric circuit structure, in which wir-
`ing pattern swarf, generated from punching out the flexible
`printed circuits, does not cause a short-circuit failure.
`
`BACKGROUND ART
`
`A panel substrate, which is a component of a flat image
`display element such as a liquid crystal panel, is an electric
`circuit substrate having, on the inner surface, various electric
`circuit elements including pixel electrodes as individual units
`of image display, switching elements for applying certain
`voltages on pixel electrodes, and metal wiring.
`Electrode terminals are disposed along the borders of the
`panel substrate of the liquid crystal panel, wherein the elec-
`trode terminals are drawn from the metal wiring formed over
`the image display region. Flexible printed circuits (FPC) are
`connected to these electrode terminals. Applied to the elec-
`trode terminals through the flexible printed circuits are vari-
`ous image display signals from peripheral circuit substrates
`and other components except the liquid crystal panel, as well
`as the power supply voltage required for the panel substrate to
`operate as an electric circuit substrate. Since the flexible
`printed circuits can be bent, the peripheral circuit substrate is
`bonded to the back of a bezel, a frame-like structural member
`with a bottom, in which the liquid crystal panel and the
`backlight are encased. This configuration constitutes a liquid
`crystal display device, which is an electric circuit structure.
`The flexible printed circuit, which connects the panel sub-
`strate and the peripheral circuit substrate, includes a flexible
`base film having a particular wiring pattern on it. The wiring
`pattern is formed with metal foil (e.g., copper foil). Further-
`more, the flexible printed circuit, together with the wiring
`pattern,
`is covered by an insulating protective layer. The
`flexible printed circuit is electrically connected to the panel
`substrate through an aperture in the base film that exposes the
`wiring pattern. Through the aperture,
`the wiring pattern
`makes direct contact with the electrode terminal on the panel
`substrate. Liquid crystal display devices also employ TCP
`(Tape Carrier Package), in which circuit elements such as
`driver semiconductor chips and capacitors that are connected
`to the wiring pattern are mounted on the flexible printed
`circuit.
`
`For easy handling, in the case of TCP, flexible printed
`circuits having circuit elements such as semiconductor chips
`mounted therein are formed in multiples on a carrier tape so as
`to be individually separated for connection to the panel sub-
`strate by being punched out from the carrier tape in a prede-
`termined shape by a metal cutter.
`Patent Document 1 discloses a technology for forming a
`wiring pattern on a flexible printed circuit, wherein the
`lengths of individual wires on the flexible printed circuit
`alternate, having every other wire shorter, where the shorter
`wire does not extend to the punching line. According to this
`technology, a short-circuit failure caused by conductive for-
`
`2
`
`eign matter, i.e., a wire detachment from the base film trig-
`gered by the stress from the punching out process, can be
`prevented.
`Patent Document 1: Japanese Utility Model Application
`Laid-Open Publication No. H4-28437
`
`SUMMARY OF THE INVENTION
`
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`65
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`Problems to be Solved by the Invention
`
`The conventional flexible printed circuit described above
`can prevent a short-circuit failure caused by wiring pattern
`swarf adhered to the edge of the flexible printed circuit gen-
`erated upon punching out, but cannot prevent a short-circuit
`failure caused by the wiring pattern swarf adhered to other
`electric circuit substrates to which the flexible printed circuit
`is connected, such as the panel substrate.
`The electrode terminals on the panel substrate are designed
`to have the largest possible width to minimize the resistance
`of the electric wiring, and therefore the interval between
`adjacent electrode terminals is narrower than the interval
`between adjacent wires of the wiring patterns on the flexible
`printed circuit, although the pitch ofthe electrode terminals is
`the same as that of the wiring pattern. For this reason, mea-
`sures must be taken to prevent short-circuit failure on the
`panel substrate as well, as long as wiring pattern swarf is an
`unavoidable byproduct ofthe punching out process offlexible
`printed circuits.
`It should be noted that, in the case of TCP, where a circuit
`element is mounted on the flexible printed circuit, all wiring
`patterns are sometimes formed across the punching line ofthe
`flexible printed circuit for quality inspection of the circuit
`components mounted on the carrier tape. In this case, the
`technology disclosed in Patent Document 1 is not applicable.
`The present invention was devised in consideration of the
`issues described above, and is aiming at providing a flexible
`printed circuit having a reduced chance of short-circuit failure
`caused by wiring pattern swarf derived from punching out the
`flexible printed circuits, and an electric circuit structure hav-
`ing the flexible printed circuit and an electric circuit substrate
`to which the flexible printed circuits are connected.
`
`Means of Solving the Problems
`
`invention,
`The flexible printed circuit of the present
`devised to solve the problems discussed above, is a flexible
`printed circuit having a wiring pattern formed on the flexible
`base film, which is individually punched out to be separated in
`a condition that the wiring pattern is formed on the base film,
`and the wiring pattern has a narrowed portion near an edge of
`the base film.
`
`invention
`The electric circuit structure of the present
`includes the flexible printed circuit of the present invention
`and an electric circuit substrate over which surface electric
`circuit elements and electrode terminals to which the electric
`
`circuit elements are connected are formed, wherein the wiring
`patterns on the flexible printed circuit are connected to the
`electrode terminals on the electric circuit substrate.
`
`Effects of the Invention
`
`According to the present invention, the length of wiring
`pattern swarf generated from punching out flexible printed
`circuits can be shortened. The present invention therefore
`provides a flexible printed circuit that prevents short-circuit
`failures caused by wiring pattern swarf, and an electric circuit
`
`COMPLAINT-3 06
`
`COMPLAINT-306
`
`

`

`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 9 of 12 Page ID #:372
`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 9 of 12 Page ID #:372
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`US 8,446,556 B2
`
`3
`structure having such a flexible printed circuit and an electric
`circuit substrate to which the flexible printed circuit is con-
`nected.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a plan view of the flexible printed circuit accord-
`ing to an embodiment of the present invention.
`FIG. 2 is a schematic structural view of the liquid crystal
`display device according to an embodiment of the present
`invention.
`
`FIG. 3 is a plan view of the carrier tape on which the
`flexible printed circuits of an embodiment of the present
`invention are formed.
`
`FIG. 4 is an enlarged view of a part of the flexible printed
`circuit of an embodiment of the present invention, before the
`flexible printed circuit is punched out from the carrier tape.
`FIG. 5 shows the relationship between the wiring pattern of
`the flexible printed circuit of an embodiment of the present
`invention and the electrode terminals on the electric circuit
`
`substrate to which the flexible printed circuit is connected.
`
`DETAILED DESCRIPTION OF EMBODIMENTS
`
`The flexible printed circuit of the present invention is a
`flexible printed circuit having a wiring pattern formed on the
`flexible base film, which flexible printed circuit is individu-
`ally punched out to be separated, along with the wiring pat-
`tern on the base film, wherein the wiring pattern has a nar-
`rowed portion near on edge of the base film.
`This structure limits the maximum length of the wiring
`pattern swarf generated from punching out
`the flexible
`printed circuits to the width of the narrowed portion of each
`wire in the wiring pattern, which is shorter than in the case of
`not having the narrowed portions. Therefore, even if the flex-
`ible printed circuit is used in a condition in which wiring
`pattern swarf is adhered to them, short-circuit failure caused
`by the swarf can effectively be prevented.
`The flexible printed circuit having the structure described
`above preferably has the aforementioned narrowed portion
`whose width is narrower than the interval between the elec-
`trode terminals formed on the electric circuit substrate to
`
`which the flexible printed circuit is connected, wherein the
`wiring pattern on the side with the narrowed portion is con-
`nected to the electrode terminals. This way, the length of the
`wiring pattern swarf is shorter than the interval between adja-
`cent electrode terminals on the electric circuit substrate to
`
`4
`
`electric circuit substrate is a panel substrate that, together
`with an opposite substrate to which the panel substrate is
`bonded through a liquid crystal layer with a predetermined
`gap therebetween, constitutes a liquid crystal panel.
`Embodiments ofthe present invention are described below
`in reference to figures.
`The following description of an embodiment ofthe present
`invention shows an example where the flexible printed circuit
`of the present invention is connected to the panel substrate of
`a liquid crystal panel to constitute a part of a liquid crystal
`display device. An example of the electric circuit structure of
`the present invention, in which the electric circuit substrate to
`which the flexible printed circuit is connected is the panel
`substrate that is a component of a liquid crystal panel, will
`also be described.
`
`The following description, however, shall not limit in any
`way the applications of the flexible printed circuit and the
`electric circuit structure of the present invention. Electric
`circuit substrates to which the flexible printed circuit of the
`present invention is connected shall not be limited to a panel
`substrate of a liquid crystal panel. The flexible printed circuit
`ofthe present invention may be connected to a panel substrate
`of an image display device or other electric circuit substrates
`for a variety of applications, such as audio devices or data
`processing devices. Similarly, the electric circuit structure of
`the present invention shall not be limited to the one for a liquid
`crystal display device. The electric circuit structure of the
`present invention may be applicable to a wide variety of flat
`display devices such as inorganic EL displays and field emis-
`sion cold cathode display devices. The electric circuit struc-
`ture of the present invention shall be applicable not only to
`display devices, but also to various modules in which flexible
`printed circuits are connected to an electric circuit substrate,
`such as drive circuits of audio devices and data processing
`devices.
`
`The following figures are schematic views of main mem-
`bers, among all other members, of an embodiment of the
`present invention in order to describe the present invention.
`Therefore, the display device of the present invention may
`have any other members which are not shown in the figures of
`reference. Dimensions of members shown in the figures may
`not accurately represent the actual dimensions or the actual
`dimensional ratio of the members.
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`FIG. 1 is a plan view that shows the configuration of the
`flexible printed circuit 100 of an embodiment of the present
`invention.
`
`which the flexible printed circuit is connected, thereby almost
`definitely preventing short-circuit failures.
`Furthermore, a circuit element connected to the aforemen-
`tioned wiring pattern is preferably mounted on the flexible
`printed circuit so that the flexible printed circuit can be used
`as a TCP.
`
`invention
`The electric circuit structure of the present
`includes the flexible printed circuit of the present invention
`and an electric circuit substrate over which surface electric
`circuit elements and electrode terminals to which the electric
`
`50
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`55
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`circuit elements are connected are formed, wherein the wiring
`pattern on the flexible printed circuit is connected to the
`electrode terminals on the electric circuit substrate.
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`60
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`This configuration provides an electric circuit structure
`that reduces the chance of short-circuit failure occurrences
`
`caused by the wiring pattern swarf generated from punching
`out flexible printed circuits along with wiring patterns on the
`base film.
`
`65
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`The aforementioned electric circuit structure is preferably
`a liquid crystal display device, wherein the aforementioned
`
`As shown in FIG. 1, flexible printed circuit 100 of the
`present invention has flexible base film 1, made of an insu-
`lating material such as polyimide and having a thickness of
`about 10 to 50 um, and has a metal foil such as copper foil
`having a thickness of about 10 to 50 um bonded to the base
`film 1 through an adhesive layer (not shown) to form pre-
`scribed wiring patterns 2 (2a, 2b and 2c). Wiring patterns 2
`are covered with insulating protective film or protective sheet
`(not shown), which makes flexible printed circuit 100 a three-
`layer structure including base film 1 and protective film or
`protective sheet with wiring patterns 2 in between.
`Flexible printed circuit 100 according to the present
`embodiment is a TCP substrate having semiconductor chip 4
`at the center. The semiconductor chip 4 outputs drive signals
`for driving the liquid crystal panel. Wiring patterns 2 are
`connected to terminal region 3 formed on the back side, i.e.,
`the side facing the wiring patterns 2, of semiconductor chip 4
`through the apertures (not shown) in the protective sheet that
`covers the surface of the wiring patterns 2. As shown in FIG.
`1, wiring patterns 2 include output wiring pattern 211, which is
`connected to the output terminal of semiconductor chip 4, and
`
`COMPLAINT-3 07
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`COMPLAINT-307
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`

`

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`US 8,446,556 B2
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`5
`input wiring pattern 2b, which is connected to the input ter-
`minal of semiconductor chip 4. Output wiring pattern 2a is
`drawn to the top edge of flexible printed circuit 100 as shown
`in FIG. 1, and input wiring pattern 2b is drawn to the bottom
`edge of flexible printed circuit 100 as shown in FIG. 1.
`Output wiring pattern 2a has narrowed portion 20 at the
`edge ofthe flexible printed circuit 100 and its adjacent region.
`Base film 1 has aperture 5a along the top edge of flexible
`printed circuit 100 in the area where output wiring pattern 2a
`is formed, and aperture 5b along the bottom edge of flexible
`printed circuit 100 in the area where input wiring pattern 2b is
`formed. Output wiring pattern 2a and input wiring pattern 2b
`are, through apertures 5a and 5b, exposed to the back side of
`flexible printed circuit 100, which is opposite the side shown
`in FIG. 1. Wiring patterns 2a and 2b are connected to elec-
`trode terminals on other electric circuit substrates (not shown)
`through the exposed portions of the wiring.
`For example, on flexible printed circuit 100 according to
`the present embodiment, a film material containing conduc-
`tive particles, which is called ACF (Anisotropic Conductive
`Film), is disposed over aperture 5a to establish physical and
`electrical connection between individual wires of output wir-
`ing pattern 2a and the corresponding electrode terminals
`formed on panel substrate 12 of liquid crystal panel 13. Like-
`wise, ACF is disposed over aperture 5b to establish physical
`and electrical connection with corresponding electrode ter-
`minals of an external circuit substrate (not shown) that gen-
`erates drive voltage and input signals for driver semiconduc-
`tor chip 4.
`FIG. 2 is a schematic structural view of the liquid crystal
`display device 200, which will be explained as an example of
`an electric circuit structure of the present invention.
`As shown in FIG. 2, liquid crystal display device 200
`according to the present embodiment has glass opposite sub-
`strate 11, glass panel substrate 12 on which electric circuit
`elements are formed, and a liquid crystal layer (not shown)
`between the substrates, wherein the substrates and the liquid
`crystal layer constitute liquid crystal panel 13. On the inner
`surface of opposite substrate 11, there are color filters for
`color image display, a unit of a color filter corresponding to
`each pixel, and an opposite electrode for applying predeter-
`mined voltages to the liquid crystal layer. On the inner surface
`of panel substrate 12, there are pixel electrodes arranged in a
`matrix of multiple rows and columns. The polarization con-
`dition ofthe liquid crystal layer is changed in accordance with
`the potential difference between the pixel electrodes and the
`opposite electrode. Therefore, the area on panel substrate 12
`where the pixel electrodes are disposed is the display area of
`the liquid crystal panel.
`The display area has a plurality of gate lines arranged in the
`direction of rows of the pixel electrodes, a plurality of source
`lines arranged in columns, and a TFT connected to a respec-
`tive pixel electrode located near the intersections of the gate
`lines and the source lines, which intersect each other at a right
`angle. The inside configuration of opposite substrate 11 and
`panel substrate 12 is not shown in the figures.
`Panel substrate 12 is slightly larger than opposite substrate
`11 in surface area, and, as shown in FIG. 2, has exposed
`surface areas along both the right and left sides and on the side
`at the bottom of liquid crystal panel 13. On these exposed
`areas, electrode terminals (not shown) are disposed for apply-
`ing predetermined voltages and signals to various wirings
`such as gate lines and source lines and to the electric circuit
`elements such as TFTs formed in the panel substrate 12.
`Wiring patterns 2 on flexible printed circuit 100 are connected
`through the ACF formed over aperture 5a to these electrode
`terminals. In this way, output signals from driver semicon-
`
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`ductor chip 4 mounted on flexible printed circuit 100 are sent
`to individual wires disposed over panel substrate 12 of liquid
`crystal panel 13 for image display on liquid crystal panel 13.
`When liquid crystal panel 13 is a transmissive or semi-
`transmissive panel, a backlight necessary to display images
`on liquid crystal panel 13 is placed behind liquid crystal panel
`13. In this case, liquid crystal panel 13 and the backlight are
`encased in a bezel, a frame-like structural member having a
`bottom, to constitute a liquid crystal module, which is a liquid
`crystal display device. These components are, however, omit-
`ted in FIG. 2.
`
`FIG. 2 shows that, for ease in explanation, flexible printed
`circuits 100 connected to the back panel 12 are expanded at
`the periphery of the panel 12. Actually, however, to minimize
`the outer dimension of the liquid crystal display device, flex-
`ible printed circuits 100 are bent along the sides of the bezel
`(not shown), with the other edge ofthe flexible printed circuit
`100 bent and bonded to the back side of the bezel.
`
`Configuration ofliquid crystal display device 200, which is
`an electric circuit substrate of the present invention, shall not
`be limited to an embodiment shown in FIG. 2, wherein the
`flexible printed circuits are connected along three borders of
`panel substrate 12. Flexible printed circuits 100 may be con-
`nected along only one border, two borders, or all four borders
`of panel substrate 12. The number of flexible printed circuits
`100 that are connected to each border ofthe panel substrate 12
`is not limited either.
`
`FIG. 3 is a plan view of a carrier tape 300 on which flexible
`printed circuits according to the present embodiment are
`formed but not punched out for separation yet.
`As shown in FIG. 3, multiple flexible printed circuits 100
`are formed apart from each other by a predetermined spacing
`on carrier tape 300. Wiring patterns 2 (2a and 2b) and semi-
`conductor chip 4, which is a circuit element, are disposed over
`flexible resin base material 6, which becomes base film 1 once
`flexible printed circuits 100 are individually separated. Flex-
`ible printed circuits 100 according to an embodiment of the
`present invention are separated when individual patterns on
`carrier tape 300 are punched out along the prescribed punch-
`ing line 7. Note that punching line 7 is actually not visible as
`shown in FIG. 3; it only represents the contour of the punch-
`ing device (not shown).
`Wiring patterns 2 on the base material 6 of carrier tape 300
`extend beyond punching line 7, wherein each wire in output
`wiring pattern 2a and input wiring pattern 2b has test pads 8a
`and 8b, respectively, located beyond the punching line 7,
`which test pads are wider than other part of wires in wiring
`patterns 2a and 2b. Test pads 8a and 8b of flexible printed
`circuit 100 according to the present embodiment can be used
`for testing the electrical properties of wiring patterns 2a and
`2b and semiconductor chip 4, which is the mounted circuit
`element, before flexible printed circuits 100 are punched out
`from carrier tape 300.
`Guides 9 along the sides of carrier tape 300 have catch
`holes 10 for reeling in and out the carrier tape 300 for pro-
`cesses such as formation of wiring patterns 2, mounting of
`semiconductor chip 4, and punching out of the flexible
`printed circuits 100.
`FIG. 4 is an enlarged plan view of a portion of flexible
`printed circuit 100 before being punched out from carrier tape
`300, showing the region around punching line 7 over output
`wiring pattern 211.
`As shown in FIG. 4, each wire of the output-side wiring
`pattern 2a has a narrowed portion 20 in the vicinity of the
`punching line 7. In other words, each wire of output wiring
`pattern 2a has a certain width throughout their length over
`aperture 5a formed in the base material 6 of carrier tape 300,
`
`COMPLAINT-3 08
`
`COMPLAINT-308
`
`

`

`Case 8:20-cv-00490 Document 1-5 Filed 03/10/20 Page 11 of 12 Page ID #:374
`Case 8:20-cv-00490 Document 1—5 Filed 03/10/20 Page 11 of 12 Page ID #:374
`
`US 8,446,556 B2
`
`7
`up to the Vicinity of punching line 7, where the wire narrows
`down to form a narrowed portion 20. Beyond this Vicinity, the
`wire regains the original width, and then becomes wider
`towards the end to form the testing pad 811.
`Since the narrowed portion 20 ofeach wire ofoutput wiring
`pattern 2a on flexible printed circuit 100 according to the
`present embodiment intersects punching line 7, narrowed
`portion 20 constitutes a part of an edge of base film 1 once the
`flexible printed circuit 100 is punched out. Thus, any wiring
`pattern swarf generated from punching out
`the flexible
`printed circuit by the cutting die has a length not greater than
`the width of narrowed portion 20.
`Employment of narrowed portion 20 on output wiring pat-
`tern 2a in the Vicinity of punching line 7 makes the length of
`wiring pattern swarf generated from punching out shorter
`than the swarfthat would result from cutting the output wiring
`pattern 2a with its full width that does not have narrowed
`portion 20.
`As described earlier, flexible printed circuit 100 according
`to the present embodiment includes resin base material 6,
`which is base film 1, over which wiring patterns 2 ofmetal foil
`are formed Via an adhesive layer. Flexible printed circuits 100
`are individually separated by being punched out from the base
`material by a cutting die. The base material 6 has certain
`flexibility, and wiring patterns 2 disposed on the adhesive
`layer may be stretched and deformed when subjected to exter-
`nal force from cutting. For these reasons, wiring pattern swarf
`generated from punching out cannot completely be avoided
`even if quality control of the shape of the cutting die and edge
`sharpness is sufliciently managed.
`Also, because the swarf easily sticks to base film 1 of
`separated flexible printed circuit 100 due to static electricity,
`complete removal of the swarf from individually separated
`flexible printed circuit 100 is extremely diflicult. Wiring pat-
`tern swarf adhered to flexible printed circuit 100, which is
`practically unavoidable as described above, can then reach
`the connection area that connects flexible printed circuit 100
`to other electric circuit substrates, and could bridge across the
`adjacent electrode terminals, causing a short-circuit failure.
`Flexible printed circuit 100 according to the present embodi-
`ment, however, shortens the length of any wiring pattern
`swarf that could be generated from punching out as described
`above, thereby reducing the chance that the swarf bridges
`across adjacent electrode terminals, which effectively pre-
`vents short-circuit failure occurrences.
`
`Swarf length could be made shorter simply by reducing the
`width ofindividual wires ofwiring patterns 2 throughout their
`length. However, excessive reduction in width of wires in
`wiring patterns 2 reduces the strength of the wiring pattern 2,
`which makes it diflicult to form certain shapes on base film 1.
`Reduction in width of wires in wiring patterns 2 can also
`contribute to poor conductiVity between wiring patterns 2 and
`the electrode terminals formed on other electric circuit sub-
`
`strate due to the reduced contact area between them. In par-
`ticular, when ACF is used for electrical connection, narrow
`wires of wiring patterns 2 make it diflicult for conductive
`particles of the ACF to make contact with wiring patterns 2,
`thereby increasing the chance of occurrence of poor conduc-
`tiVity. Therefore, as shown in FIG. 4, each wire in output
`wiring pattern 2a preferably retains its full width at least in the
`Vicinity of aperture 5a,
`i.e., the connection area through
`which flexible printed circuit 100 is connected with electrode
`terminals formed on other electric circuit substrate, and nar-
`rowed portion 20 is preferably formed along the edge of base
`film 1 of flexible printed circuit 100, that is, along the punch-
`ing line 7.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`8
`FIG. 5 shows the relationship between the border area of
`flexible printed circuit 100 and electrode terminals 14 formed
`on panel substrate 12, the electric circuit substrate to which
`flexible printed circuit 100 is connected.
`As shown in FIG. 5, the pitch P2 of output wiring patterns
`2 on flexible printed circuit 100 and the pitch P1 of electrode
`terminals 14 on panel substrate 12, to which output wiring
`pattern 2a is connected, are equal. However, to accommodate
`any reduced conductive area resulting from misalignment in
`the placement of flexible printed circuit 100 or misalignment
`caused by stretched material, electrode terminals 14 have a
`width “D” which is larger than width “A” of output wiring
`pattern 211. That is, interval “E” between adjacent electrode
`terminals 14 is smaller than interval “B” between wires of
`
`output wiring pattern 211.
`Here is a numerical design example. If the pitch P2 of
`output wiring pattern 2a and the pitch P1 of electrode termi-
`nals 14 are both 50 um, both width “A” of output wiring
`pattern 2a and interval “B” are often set to 25 um, and the
`width “D” of electrode terminal 14 and the interval “E” are
`
`often set to 35 um and 15 um, respectively, making the width
`“D” of electrode terminals 14 larger.
`If width “C” of narrowed portion 20 of output wiring pat-
`tern 2a is set to a smaller value than interval “E” of the
`
`electrode terminals 14, for example, to 13 um, a half value of
`the width of output wiring pattern 2a in the example above,
`any swarf generated from narrowed portion 20 has a length
`“C”, which is shorter than interval “E” of electrode terminals
`14. Consequently, the wiring pattern swarf would not brid