Flexible circuit board, cof module, and electronic device comprising same

Abstract

A flexible circuit board according to an embodiment comprises: a substrate; a conductive pattern part disposed on the substrate; and a protective layer disposed on the substrate and including an open region, wherein at least one of the substrate, the conductive pattern part, and the protective layer includes a concave part recessed in the thickness direction of the substrate, and the concave part does not penetrate at least one of the substrate, the wiring pattern part, and the protective layer along the thickness direction.

Description

Flexible circuit board, COF module, and electronic device including the same

[0001] The embodiment relates to a flexible circuit board, a COF module, and an electronic device including the same.

[0002] Recently, various electronic products are becoming thinner and smaller. Accordingly, it is required to mount semiconductor chips at high density in a narrow area of ​​the electronic products.

[0003] A COF (Chip On Film) comprises a circuit board and a chip disposed on the circuit board. The circuit board is flexible. That is, the COF is a flexible circuit board. Accordingly, the COF is applied to flexible displays. For example, the COF can be applied to various wearable electronic devices. Additionally, the COF has a fine pitch, and accordingly, the COF is applied to displays having high resolution.

[0004] The chip includes semiconductor chips. For example, the chip may be an Integrated Circuit (IC) chip or a Large Scale Integrated Circuit (LSI) chip.

[0005] The chip is connected to an external circuit board and a display panel through a circuit pattern. For example, a pad is provided at each end of the circuit pattern. One pad is electrically connected to a terminal of the chip. The other pad is connected to a terminal of the external circuit board and the display panel. Accordingly, the chip, the external circuit board, and the display panel are electrically connected through the COF. As a result, a signal is transmitted to the display panel through the circuit pattern.

[0006] Meanwhile, the aforementioned flexible circuit board is equipped with a mark portion for verifying production history, etc., during the manufacturing process. In the prior art, a mark portion is formed on the outermost layer of the flexible circuit board through ink marking. The aforementioned mark portion has a problem of being vulnerable to counterfeiting as it is easily erased due to the characteristics of the ink. In addition, there are problems such as reduced productivity due to clogged ink nozzles or the need to refill ink, and a relatively small number of characters or sizes that can be marked.

[0007] Therefore, a mark formation method capable of preventing forgery and improving productivity is required.

[0008] An embodiment provides a flexible circuit board having a mark portion capable of preventing counterfeiting and improving productivity, a COF module, and an electronic device including the same.

[0009] In addition, the embodiment provides a flexible circuit board having a mark portion with improved design freedom, a COF module, and an electronic device including the same.

[0010] In addition, a flexible circuit board, a COF module, and an electronic device including the same are provided, which can prevent reliability degradation caused by the mark portion.

[0011] The technical problems to be solved in the proposed embodiments are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the proposed embodiments belong from the description below.

[0012] A flexible circuit board according to an embodiment comprises a substrate; a conductive pattern portion disposed on the substrate; and a protective layer disposed on the substrate and including an open area, wherein at least one of the substrate, the conductive pattern portion, and the protective layer includes a concave portion provided concavely in the thickness direction of the substrate, and the concave portion does not penetrate at least one of the substrate, the wiring pattern portion, and the protective layer along the thickness direction.

[0013] In addition, the above-mentioned concave portion is a laser mark indicating manufacturing history information of the flexible circuit board.

[0014] Additionally, the above-described material includes a first surface on which the conductive pattern portion and the protective layer are disposed, and a second surface opposite to the first surface on which the conductive pattern portion and the protective layer are not disposed, wherein the conductive pattern portion includes a wiring pattern portion on which an effective signal is transmitted, and a dummy pattern portion having a different function from the wiring pattern portion, and the concave portion is provided in at least one of the first surface of the above-described material, the second surface of the above-described material, the dummy pattern portion, and the protective layer.

[0015] Additionally, the above-mentioned concave portion is provided on the first surface of the above-mentioned substrate, and the concave portion provided on the first surface of the above-mentioned substrate does not overlap with the wiring pattern portion and the dummy pattern portion along the thickness direction, but overlaps with the open area of ​​the protective layer along the thickness direction.

[0016] In addition, the above-mentioned concave portion is provided on the second surface of the above-mentioned substrate, and the concave portion provided on the second surface of the above-mentioned substrate does not overlap with the wiring pattern portion along the thickness direction.

[0017] Additionally, the concave portion is provided on one side of the dummy pattern portion, and the concave portion provided on one side of the dummy pattern portion overlaps with the open area of ​​the protective layer along the thickness direction.

[0018] In addition, the above-mentioned concave portion is provided on one surface of the protective layer, and the concave portion provided on one surface of the protective layer does not overlap with the wiring pattern portion along the thickness direction.

[0019] Additionally, the conductive pattern portion includes a wiring pattern portion through which an effective signal is transmitted, and a dummy pattern portion having a different function from the wiring pattern portion; the substrate includes a first surface and a second surface opposite to the second surface; the wiring pattern portion includes an upper wiring pattern portion provided on the first surface of the substrate and a lower wiring pattern portion provided on the second surface of the substrate; the dummy pattern portion includes an upper dummy pattern portion provided on the first surface of the substrate and a lower dummy pattern portion provided on the second surface of the substrate; the protective layer includes an upper protective layer disposed on the first surface of the substrate and having an open area, and a lower protective layer disposed on the second surface of the substrate and having an open area; and the concave portion is provided in at least one of the first surface of the substrate, the second surface of the substrate, the upper dummy pattern portion, the lower dummy pattern portion, the upper protective layer, and the lower protective layer.

[0020] Additionally, the above-mentioned concave portion includes at least one of a first concave portion provided on the first surface of the above-mentioned substrate and a second concave portion provided on the second surface of the above-mentioned substrate, wherein the first concave portion overlaps with the open area of ​​the upper protective layer along the thickness direction and does not overlap with the upper wiring pattern portion and the lower wiring pattern portion, and the second concave portion overlaps with the open area of ​​the lower protective layer along the thickness direction and does not overlap with the upper wiring pattern portion and the lower wiring pattern portion.

[0021] Additionally, the first concave portion overlaps with the lower dummy pattern portion along the thickness direction, and the second concave portion overlaps with the upper dummy pattern portion along the thickness direction.

[0022] Additionally, the concave portion is provided on at least one of the upper dummy pattern portion that overlaps with the open area of ​​the upper protective layer along the thickness direction and the lower dummy pattern portion that overlaps with the open area of ​​the lower protective layer along the thickness direction.

[0023] Additionally, the concave portion is provided on at least one of the upper protective layer that does not overlap with the upper wiring pattern portion along the thickness direction and the lower protective layer that does not overlap with the lower wiring pattern portion along the thickness direction.

[0024] In addition, the flexible circuit board further includes a filling portion provided to fill the concave portion.

[0025] The flexible circuit board of the embodiment includes a substrate, a conductive pattern portion, and a protective layer. The conductive pattern portion includes a wiring pattern portion and a dummy pattern portion. At this time, at least one of the substrate, the wiring pattern portion, and the protective layer includes a recess provided along the thickness direction of the substrate, which does not penetrate at least one of the substrate, the wiring pattern portion, and the protective layer. At this time, the recess is a laser mark indicating manufacturing history information of the flexible circuit board.

[0026] That is, the embodiment displays manufacturing history information by forming a recess using a laser on at least one of the substrate, the wiring pattern portion, and the protective layer. Accordingly, the embodiment can improve the security of manufacturing history information compared to a comparative example using ink, and thereby improve the productivity of the flexible circuit board, which can improve product yield.

[0027] In this case, when a concave portion is provided in the substrate, the concave portion is provided so as not to overlap with the wiring pattern portion and the protective layer along the thickness direction. Through this, the embodiment can easily provide manufacturing history information without affecting the physical reliability and / or electrical reliability of the flexible circuit board.

[0028] In addition, when a concave portion is provided in a dummy pattern portion, the concave portion does not overlap with the protective layer along the thickness direction, thereby enabling easy identification of the concave portion provided in the dummy pattern portion from the outside.

[0029] In addition, when a recess is provided in the protective layer, the recess is ensured not to overlap with the wiring pattern along the thickness direction. Through this, the embodiment can solve the problem where the wiring pattern is not reliably protected by the recess, and thereby easily provide manufacturing history information without affecting the physical reliability and / or electrical reliability of the flexible circuit board.

[0030] FIGS. 1a and FIGS. 1b are schematic plan views of a flexible circuit board according to a first embodiment.

[0031] FIGS. 2a and FIGS. 2b are cross-sectional views showing a concave portion according to a first embodiment.

[0032] FIG. 3 is a cross-sectional view showing a concave portion according to a second embodiment.

[0033] FIG. 4 is a cross-sectional view showing a concave portion according to a third embodiment.

[0034] FIG. 5 is a cross-sectional view showing a concave portion according to the fourth embodiment.

[0035] FIG. 6 is a cross-sectional view showing a concave portion according to the fifth embodiment.

[0036] FIG. 7 is a cross-sectional view showing a concave portion according to the 6th embodiment.

[0037] FIG. 8 is a cross-sectional view showing a concave portion according to the 7th embodiment.

[0038] FIG. 9 is a plan view showing a flexible circuit board according to a second embodiment.

[0039] FIGS. 10a and FIGS. 10b are schematic plan views of a flexible circuit board according to a third embodiment.

[0040] FIGS. 11a and FIGS. 11b are schematic plan views of a flexible circuit board according to a fourth embodiment.

[0041] FIG. 12 is a cross-sectional view showing a concave portion according to the 8th embodiment.

[0042] FIG. 13 is a cross-sectional view showing the layer structure of a conductive pattern portion according to the first embodiment.

[0043] FIG. 14 describes the layer structure of the conductive pattern portion according to the second embodiment.

[0044] FIGS. 15 and 16 are drawings for explaining the connection between a COF module and other members according to an embodiment.

[0045] FIGS. 17 to 19 are drawings relating to an electronic device including a flexible circuit board according to an embodiment.

[0046] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0047] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0048] Furthermore, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as “and at least one of B and C (or more than one),” it may include one or more of all combinations that can be formed from A, B, and C.

[0049] In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are used merely to distinguish the components from other components and are not intended to limit the essence, order, or sequence of the components.

[0050] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0051] Additionally, where described as being formed or placed on the "top or bottom" of each component, the top or bottom includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components.

[0052] In addition, when expressed as “up” or “down,” it can include the meaning of a downward direction as well as an upward direction relative to a single component.

[0053]

[0054] Hereinafter, with reference to the drawings, a flexible circuit board according to an embodiment and a COF module including the same will be described.

[0055]

[0056] FIGS. 1a and 1b are schematic plan views of a flexible circuit board according to a first embodiment. Specifically, FIG. 1a is a schematic plan view of one side of a flexible circuit board according to a first embodiment with a protective layer removed, and FIG. 1b is a schematic plan view of one side of a flexible circuit board according to a first embodiment with a protective layer disposed thereon.

[0057] Prior to the description of the present invention, the flexible circuit board may be a flexible circuit board for a COF having at least one chip mounting area. However, the embodiments are not limited thereto, and the flexible circuit board may be a flexible circuit board for a connector that does not have a chip mounting area. For example, the flexible circuit board may connect a display panel and an external circuit board, wherein the chip may be placed on the external circuit board described above. In this case, the flexible circuit board may simply function to electrically connect the display panel and the external circuit board.

[0058] Referring to FIG. 1a and FIG. 1b, a flexible circuit board (1000) according to the first embodiment includes a substrate (100), a wiring pattern portion (WP), a dummy pattern portion (DP), and a protective layer (800).

[0059] The substrate (100) includes one side and another side opposite to the one side. At this time, the one side of the substrate (100) may refer to the upper surface of the substrate (100) on which the wiring pattern portion (WP), dummy pattern portion (DP), and protective layer (800) are arranged. The other surface of the substrate (100) may refer to the lower surface of the substrate (100).

[0060] Here, the flexible circuit board (1000) of the first embodiment may be a single-sided flexible circuit board having a wiring pattern portion (WP), a dummy pattern portion (DP), and a protective layer (800) provided only on one side of the substrate (100). Accordingly, the conductive pattern portion (WP, DP) and the protective layer (800) are disposed on one side of the substrate (100).

[0061] The substrate (100) may not represent the final manufactured flexible circuit board (1000). For example, the final manufactured flexible circuit board (1000) may not include some areas of the substrate (100) shown in FIG. 1a and FIG. 1b. For example, some areas of the substrate (100) shown in FIG. 1a and FIG. 1b may be cut and removed along a cutting line.

[0062] For example, a conductive pattern portion (WP, DP), a protective layer (800), and a chip (not shown) are disposed on a substrate (100). Subsequently, the substrate (100) can be cut along a cutting line, and a COF module can be manufactured accordingly. Thus, the perimeter of the finally manufactured COF module can correspond to the cutting line of the substrate (100) in FIGS. 1A and FIGS. 1B. Additionally, a conductive pattern portion (WP, DP) and a protective layer (800) located outside the cutting line and removed may be provided on the substrate (100), but FIGS. 1A and FIGS. 1B may only show the conductive pattern portion (WP, DP) and the protective layer (800) located inside the cutting line.

[0063] The substrate (100) includes an effective area (AA) and a non-effective area (UA). Specifically, one side of the substrate (100) includes an effective area (AA) and a non-effective area (UA) excluding the effective area (AA).

[0064] The valid area (AA) and the invalid area (UA) are separated by a cutting line. The valid area (AA) is the inner region of the area separated by the cutting line. Additionally, the invalid area (UA) is the outer region of the area separated by the cutting line.

[0065] A conductive pattern portion (WP, DP), a protective layer (800), and a chip (not shown) may be disposed on the effective area (AA). Additionally, a dummy pattern (not shown) and a sprocket hole (SH) may be provided on the non-effective area (UA). The dummy pattern provided on the non-effective area (UA) increases the strength of the substrate (100).

[0066] Additionally, the flexible circuit board (1000) can be manufactured by winding or unwinding it in a roll-to-roll manner through the sprocket hole (SH).

[0067] The substrate (100) includes a chip mounting area (CHA). The chip mounting area (CHA) may be provided on one side of the substrate (100). The chip mounting area (CHA) may be located in an effective area (AA) of the substrate (100). A chip (not shown) may be mounted on the chip mounting area (CHA). At this time, the pads of the conductive pattern portions (WP, DP) may be located within the chip mounting area (CHA).

[0068] The protective layer (800) may not be placed on the chip mounting area (CHA). For example, the protective layer (800) may include a first open area (OR) that overlaps along a vertical direction with respect to the chip mounting area (CHA). The planar area of ​​the first open area (OR) of the protective layer (800) may be larger than the planar area of ​​the chip mounting area (CHA). For example, the perimeter of the inner surface of the first open area (OR) of the protective layer (800) may be provided to surround the chip mounting area (CHA) at a position spaced apart from the chip mounting area (CHA). Through this, process characteristics in the process of mounting a chip in the chip mounting area (CHA) can be improved, and the chip can be mounted more stably.

[0069] The protective layer (800) may further include a second open area and a third open area. That is, the substrate (100) may include a substrate connection area (not shown) to which an external circuit board is connected. Additionally, the substrate (100) may include a panel connection area (not shown) to which a display panel is connected. For example, the substrate (100) may include a first side end (110E1) and a second side end (110E2) facing in a first direction (1D). Also, the substrate (100) may include a substrate area provided in an area adjacent to the first side end (110E1). Additionally, the substrate (100) may include a panel connection area provided in an area adjacent to the second side end (110E2).

[0070] The protective layer (800) may not be placed on the substrate connection area. That is, the protective layer (800) may include a second open area that overlaps along a vertical direction with respect to the substrate connection area. Additionally, the protective layer (800) may not be placed on the panel connection area. That is, the protective layer (800) may include a third open area that overlaps along a vertical direction with respect to the panel connection area.

[0071] The substrate (100) comprises a flexible material. For example, the substrate (100) may comprise polyimide (PI). However, the embodiments are not limited thereto. The substrate (100) may comprise a polymer material including polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). Accordingly, the flexible circuit board (1000) can be applied to various electronic devices including curved display devices.

[0072] The substrate (100) may have a thickness of 20 µm to 100 µm. For example, the substrate (100) may have a thickness of 25 µm to 50 µm. For example, the substrate (100) may have a thickness of 30 µm to 40 µm. If the thickness of the substrate (100) exceeds 100 µm, the overall thickness of the flexible circuit board increases. As a result, the flexible characteristics of the flexible circuit board (1000) may be degraded. Additionally, if the thickness of the substrate (100) is less than 20 µm, the substrate (100) may be damaged by heat and pressure applied during the process of mounting a chip on the flexible circuit board (1000).

[0073] A conductive pattern portion (WP, DP) and a protective layer (800) are disposed on a substrate (100). The conductive pattern portion (WP, DP) and the protective layer (800) are disposed on one side of the substrate (100). For example, the conductive pattern portion (WP, DP) and the protective layer (800) may be disposed on an effective area (AA) of the substrate (100). Additionally, the conductive pattern portion (WP, DP) and the protective layer (800) may be optionally disposed on an ineffective area (UA) of the substrate (100).

[0074] The conductive pattern section (WP, DP) may include a wiring pattern section (WP) and a dummy pattern section (DP) depending on the function. The wiring pattern section (WP) and the dummy pattern section (DP) may include the same metallic material. The wiring pattern section (WP) and the dummy pattern section (DP) may have the same layer structure. Here, the wiring pattern section (WP) and the dummy pattern section (DP) may be distinguished based on whether an effective signal is transmitted. Alternatively, the wiring pattern section (WP) and the dummy pattern section (DP) may be distinguished based on whether a signal is transmitted and / or received between multiple components.

[0075] The wiring pattern section (WP) may refer to a conductive pattern through which an effective signal is transmitted. Here, the effective signal may include a control signal transmitted to control a specific component, a signal obtained from a specific component, and / or a power signal, etc. Additionally, the wiring pattern section (WP) may refer to a conductive pattern through which a signal is transmitted and / or received between multiple components. For example, the wiring pattern section (WP) may electrically connect a chip and an external circuit board, a chip and a display panel, or an external circuit board and a display panel.

[0076] The dummy pattern section (DP) may refer to a conductive pattern in which no valid signal is transmitted. Alternatively, the dummy pattern section (DP) may refer to a conductive pattern that is not electrically connected between multiple components. For example, the dummy pattern section (DP) may refer to a conductive pattern in which a valid signal (e.g., a test signal, etc.) is transmitted, but which is not electrically connected between the chip and the external circuit board, between the chip and the display panel, or between the external circuit board and the display panel. For example, the dummy pattern section (DP) may be electrically connected to any one of the components among the chip, the external circuit board, and the display panel, but not electrically connected to other components. The dummy pattern section (DP) may refer to a conductive pattern that performs at least one of a test function, a dummy function, a heat dissipation function, and a rigidity reinforcement function.

[0077] At least one of the wiring pattern portion (WP) and the dummy pattern portion (DP) may include pads disposed within the open area (OR) of the protective layer (800). In this case, the pads disposed within the open area (OR) of the protective layer (800) may be referred to as inner pads. Additionally, at least one of the wiring pattern portion (WP) and the dummy pattern portion (DP) may include pads disposed between the first side end of the protective layer (800) and the first side end of the substrate (100) that are not covered by the protective layer (800), and this may be referred to as a first outer pad. Additionally, at least one of the wiring pattern portion (WP) and the dummy pattern portion (DP) may include pads disposed between the second side end of the protective layer (800) and the second side end of the substrate (100) that are not covered by the protective layer (800), and this may be referred to as a second outer pad.

[0078] The wiring pattern section (WP) may include a first wiring pattern section (200), a second wiring pattern section (300), and a third wiring pattern section (400) depending on the placement location and / or function.

[0079] At this time, the wiring pattern portion (WP) of the flexible circuit board (1000) of the first embodiment is placed only on one side of the substrate (100), and accordingly, the wiring pattern portion (WP) in the first embodiment can be referred to as an upper wiring pattern portion or a lower wiring pattern portion.

[0080] One end of the first wiring pattern section (200) may be located within the first open area (OR) of the protection layer (800) and the other end may be located within the second open area of ​​the protection layer (800). For example, one end of the first wiring pattern section (200) may be connected to a chip, and the other end of the first wiring pattern section (200) may be connected to an external circuit board. That is, the first wiring pattern section (200) may refer to a wiring pattern that electrically connects the chip and the external circuit board. For example, the first wiring pattern section (200) may include a first pad placed within the first open area (OR), a second pad placed within the second open area, and a connecting wire connecting the first pad and the second pad.

[0081] The first wiring pattern section (200) may include a first-1 wiring pattern section (210) and a first-2 wiring pattern section (220) according to the arrangement structure and / or connection structure. The first-1 wiring pattern section (210) may be arranged such that one connecting wire connects between one first pad and one second pad. The first-2 wiring pattern section (220) may be arranged such that one connecting wire connects between a plurality of first pads and / or a plurality of second pads.

[0082] For example, the number of interconnected connecting wires, first pads, and second pads in the first-1 wiring pattern section (210) may be the same. For example, the number of interconnected connecting wires, first pads, and second pads in the first-2 wiring pattern section (220) may be different. For example, in the first-2 wiring section (220), one connection pattern may connect two or more first pads and one second pad. Or, in the first-2 wiring section (220), one connection pattern may connect one first pad and two or more second pads. Or, in the first-2 wiring section (220), one connection pattern may connect two or more first pads and two or more second pads.

[0083] The first-1 wiring pattern section (210) may include a first pad (210P1) disposed within a first open area (OR). The first pad (210P1) of the first-1 wiring pattern section (210) may be connected to a chip. The first-1 wiring pattern section (210) may include a second pad (210P2) disposed within a second open area. The second pad (210P2) of the first-1 wiring pattern section (210) may be connected to an external circuit board. The first-1 wiring pattern section (210) may include a first connection pattern (210T) connecting the first pad (210P1) and the second pad (210P2). The first connection pattern (210T) of the first-1 wiring pattern section (210) may be covered by a protective layer (800). At this time, the first connection pattern (210T) of the first-1 wiring pattern section (210) may further include an area not covered by the protective layer (800). For example, the first connection pattern (210T) of the first-1 wiring pattern section (210) may include a first part connected to the first pad (210P1) of the first-1 wiring pattern section (210) and disposed within the first open area (OR) of the protective layer (800). Additionally, the first connection pattern (210T) of the first-1 wiring pattern section (210) may include a second part connected to the second pad (210P2) of the first-1 wiring pattern section (210) and located within the second open area of ​​the protective layer (800).

[0084] Additionally, the first-1 wiring pattern section (210) may include a plurality of first-1 wiring patterns that are spaced apart from each other and arranged on the substrate (100), and include the first pad (210P1), second pad (210P2), and first connection pattern (210T) described above.

[0085] The first-2 wiring pattern section (220) may include a plurality of third pads (220P1) spaced apart from each other and disposed within a first open area (OR). The plurality of third pads (220P1) of the first-2 wiring pattern section (220) may each be connected to different terminals of the chip. The first-2 wiring pattern section (220) may include a plurality of fourth pads (220P2) disposed within a second open area. The plurality of fourth pads (220P2) of the first-2 wiring pattern section (220) may be connected to an external circuit board. The first-2 wiring pattern section (220) may include a second connection pattern (220T) connecting the plurality of third pads (220P1) of the first-2 wiring pattern section (220) and the plurality of fourth pads (220P2) of the first-2 wiring pattern section (220). That is, the second connection pattern (220T) of the first-second wiring pattern section (220) may include a plurality of branch lines, at least one of a plurality of one end and a plurality of other ends. Additionally, the plurality of branch lines of the second connection pattern (220T) provided at one end of the first-second wiring pattern section (220) may be connected to a plurality of third pads (220P1) of the first-second wiring pattern section (220). Furthermore, the plurality of branch lines of the second connection pattern (220T) provided at the other end of the first-second wiring pattern section (220) may be connected to a plurality of fourth pads (220P2) of the first-second wiring pattern section (220).

[0086] Additionally, the first-second wiring pattern section (220) may include a plurality of first-second wiring patterns each comprising a second connection pattern (220T) that includes the aforementioned third pad (220P1), fourth pad (220P2), and a plurality of branch lines, which are spaced apart from each other.

[0087] One end of the second wiring pattern section (300) may be located within the first open area (OR) of the protection layer (800) and the other end may be located within the third open area of ​​the protection layer (800). For example, one end of the second wiring pattern section (300) may be connected to a chip, and the other end of the second wiring pattern section (300) may be connected to a display panel. That is, the second wiring pattern section (300) may refer to a wiring pattern that electrically connects the chip and the display panel. For example, the second wiring pattern section (300) may include a fifth pad (310P1, 320P1) placed within the first open area (OR), a sixth pad (310P2, 320P2) placed within the third open area, and a third connecting wire (310T, 320T) connecting them.

[0088] The second wiring pattern section (310) may include a second-1 wiring pattern section (310) and a second wiring pattern section (320) depending on the location. The second-1 wiring pattern section (310) may have a fifth pad (310P1) provided on the upper side of the first open area (OR), and the second-2 wiring pattern section (320) may have a fifth pad (32OP1) provided on the lower side of the first open area (OR). Additionally, the third connecting wire (310T) of the second-1 wiring pattern section (310) may be positioned on the upper side of the first open area (OR) toward the second side end (110E2) of the substrate (100) and connected to the sixth pad (310P2) of the second-1 wiring pattern section (310). And, the third connecting wire (320T) of the second-2 wiring pattern section (320) is positioned below the first open area (OR) while avoiding other wiring patterns or a dummy pattern section (DP) and can be connected to the sixth pad (320P2) of the second-2 wiring pattern section (320).

[0089] One end of the third wiring pattern section (400) may be located within the second open area of ​​the protection layer (800) and the other end may be located within the third open area of ​​the protection layer (800). For example, one end of the third wiring pattern section (400) may be connected to an external circuit board, and the other end of the third wiring pattern section (400) may be connected to a display panel. That is, the third wiring pattern section (400) may refer to a wiring pattern that electrically connects the external circuit board and the display panel. For example, the third wiring pattern section (400) may include a seventh pad (400P1) placed within the second open area, an eighth pad (400P2) placed within the third open area, and a fourth connecting wire (400T) connecting the seventh pad (400P1) and the eighth pad (400P2).

[0090] Additionally, the third wiring pattern section (400) may include a plurality of third wiring patterns spaced apart from each other, each including the aforementioned seventh pad (400P1), eighth pad (400P2), and fourth connecting wire (400T).

[0091] The third wiring pattern section (400) may be a bypass wiring pattern. For example, the third wiring pattern section (400) may be a power wiring line. Accordingly, the external circuit board and the display panel may receive power through the third wiring pattern section (400).

[0092] The line width of the third wiring pattern section (400) may be larger than the line width of the first and second wiring pattern sections (300, 400). This enables stable power supply.

[0093] One end of the first dummy pattern portion (500) may be located in the first open area (OR), and the other end may be covered by a protective layer (800). For example, one end of the first dummy pattern portion (500) may be connected to a chip, and the other end may not be electrically connected to other components.

[0094] The first dummy pattern section (500) may include a ninth pad (510P, 520P, 530P) disposed within the first open area (OR), and a fifth connecting wire (510T, 520T, 530T) connected to the ninth pad (510P, 520P, 530P).

[0095] The first dummy pattern section (500) may include a first-1 dummy pattern section (510), a first-2 dummy pattern section (520), and a first-3 dummy pattern section (530) depending on the location.

[0096] The ninth pad (510P) of the first-1 dummy pattern section (510) may be located below the first open area (OR), and the fifth connecting wire (510T) of the first-1 dummy pattern section (510) may be connected to the ninth pad (510P) and extended in a direction toward the first side end (110E1) of the substrate (100).

[0097] The ninth pad (520P) of the first-second dummy pattern section (520) may be located to the left of the first open area (OR), and the fifth connecting wire (520T) of the first-second dummy pattern section (520) may be connected to the ninth pad (520P) and extended in a direction toward the left end of the substrate (100).

[0098] The ninth pad (530P) of the first-third dummy pattern section (530) may be located to the right of the first open area (OR), and the fifth connecting wire (530T) of the first-third dummy pattern section (530) may be connected to the ninth pad (530P) and extended in a direction toward the right end of the substrate (100).

[0099] The first dummy pattern section (500) described above is connected to the chip and can be used to test a specific terminal of the chip or to perform a heat dissipation function to transfer heat generated from the chip.

[0100] One end of the second dummy pattern portion (600) may be located in the third open area, and the other end may be covered by a protective layer (800). For example, one end of the second dummy pattern portion (600) may be connected to a display panel, and the other end may not be electrically connected to other components.

[0101] The second dummy pattern section (600) may include a first pad (610P) disposed within a third open area, and a sixth connecting wire (610T) connected to the first pad (610P).

[0102] The aforementioned second dummy pattern section (600) is connected to a display panel and can be used to test a specific signal line of the display panel or to perform a heat dissipation function to transfer heat generated from the display panel.

[0103] One end of the third dummy pattern portion (700) may be located in the second open area, and the other end may be covered by a protective layer (800). For example, one end of the third dummy pattern portion (700) may be connected to an external circuit board, and the other end may not be electrically connected to other components.

[0104] The third dummy pattern section (700) may include a first pad (710P) disposed within the second open area, and a seventh connecting wire (710T) connected to the first pad (710P).

[0105] The aforementioned third dummy pattern section (700) is connected to an external circuit board and can be used to test specific signal lines of the external circuit board or to perform a heat dissipation function to transfer heat generated from the external circuit board.

[0106] In addition, the aforementioned dummy pattern section (DP) can perform a reinforcing function, thereby preventing the flexible circuit board (1000) from bending. Furthermore, the line width and spacing of the wiring pattern section (WP) can be made uniform by the dummy pattern section (DP).

[0107] The protective layer (800) is disposed on the substrate (100) and may include a plurality of open regions. For example, the protective layer (800) may include a first open region (OR). The first open region (OR) may overlap along a vertical direction with the chip mounting region (CHA).

[0108] The protective layer (800) may include a second open area and a third open area. In this case, the second open area and the third open area may be intentionally formed open areas, or they may be parts formed by not placing the protective layer (800) in the corresponding area.

[0109] For example, the lower end of the protective layer (800) may be located further inward than the first side end (110E1) of the substrate (100). Accordingly, a second open area may be provided between the lower end of the protective layer (800) and the first side end (110E1) of the substrate (100).

[0110] Additionally, the upper end of the protective layer (800) may be located further inward than the second side end (110E2) of the substrate (100). Accordingly, a third open area may be provided between the upper end of the protective layer (800) and the second side end (110E2) of the substrate (100).

[0111]

[0112] Meanwhile, at least one of the material (100), dummy pattern portion (DP), and protective layer (800) of the first embodiment may be provided with a recess (CP). The recess (CP) described above may be a mark containing manufacturing information of the flexible circuit board (1000). For example, the manufacturing information may be lot information. That is, the manufacturing information may include the manufacturer and manufacturing history information of the product.

[0113] At this time, the manufacturing information described above varies from product to product. That is, even if products are manufactured simultaneously, different manufacturing information may be assigned depending on the manufacturing history of the product.

[0114] Accordingly, the aforementioned manufacturing information may be difficult to implement by patterning the dummy pattern section (DP). That is, in order for different manufacturing information to be assigned to each product, masks or the like must be prepared to pattern different manufacturing information for each product, and this may lead to reduced productivity or product yield.

[0115] In addition, the aforementioned manufacturing information can be formed on the outermost layer of a flexible circuit board using ink, but due to the characteristics of the ink, it has the problem of being vulnerable to damage and having low productivity.

[0116] Accordingly, the first embodiment forms a recess (CP) in at least one of the substrate (100), the dummy pattern portion (DP), and the protective layer (800) so as to form a recess (CP) that allows the manufacturing information of the product to be verified without affecting productivity and product yield.

[0117] At this time, the concave portion (CP) may be formed in at least one of the substrate (100), the dummy pattern portion (DP), and the protective layer (800). Furthermore, the concave portion (CP) must be identifiable from the outside after the flexible circuit board (1000) is finally manufactured. Accordingly, when the concave portion (CP) is formed in the substrate (100), the concave portion (CP) may be provided in a region of the substrate (100) where the dummy pattern portion (DP) and the protective layer (800) are not formed. Additionally, when the concave portion (CP) is formed in the dummy pattern portion (DP), it may be provided in an open region (OR) of the protective layer (800) that is not covered by the protective layer (800). Additionally, when the concave portion (CP) is provided in the protective layer (800), the location where the concave portion (CP) is provided in the protective layer (800) may not be significantly limited. However, if the concave portion (CP) is provided in the protective layer (800), the wiring pattern portion (WP) covered by the protective layer (800) may not be reliably protected by the concave portion (CP). Therefore, the concave portion (CP) may be provided on one side of the protective layer (800) that does not overlap with the wiring pattern portion (WP) along the thickness direction.

[0118] Below, the concave portion (CP) according to the embodiment is described in detail.

[0119] FIGS. 2a and 2b are cross-sectional views showing a concave portion according to a first embodiment, FIG. 3 is a cross-sectional view showing a concave portion according to a second embodiment, FIG. 4 is a cross-sectional view showing a concave portion according to a third embodiment, FIG. 5 is a cross-sectional view showing a concave portion according to a fourth embodiment, FIG. 6 is a cross-sectional view showing a concave portion according to a fifth embodiment, FIG. 7 is a cross-sectional view showing a concave portion according to a sixth embodiment, and FIG. 8 is a cross-sectional view showing a concave portion according to a seventh embodiment.

[0120] Referring to FIGS. 2a and 2b, according to one embodiment, a flexible circuit board (1000) has a concave portion (CP). At this time, the concave portion (CP) may be provided in the substrate (100) of the flexible circuit board (1000).

[0121] At this time, the substrate (100) has one side and another side opposite to the one side. In addition, the flexible circuit board of the first embodiment may have a wiring pattern portion (WP) and a dummy pattern portion (DP) disposed on one side of the substrate (100).

[0122] Accordingly, according to the embodiment of FIG. 2a, the concave portion (CP) may be provided on one side of the substrate (100). Alternatively, according to the embodiment of FIG. 2b, the concave portion (CP) may be provided on the other side of the substrate (100).

[0123] At this time, the protective layer (800) is not provided on the other side of the substrate (100), and accordingly, when the concave portion (CP) is provided on the other side of the substrate (100), the placement position of the concave portion (CP) on the other side of the substrate (100) may not be significantly limited.

[0124] Additionally, a protective layer (800) is provided on one side of the substrate (100). Accordingly, when a concave portion (CP) is provided on one side of the substrate (100), the concave portion (CP) may be provided in an area that does not overlap with the protective layer (800) along the thickness direction. For example, the concave portion (CP) may be provided in an area that overlaps with the open area (OR) of the protective layer (800) in the thickness direction. For example, the concave portion (CP) may be provided in an area on one side of the substrate (100) that is not covered by the protective layer (800). Accordingly, the concave portion (CP) provided in the substrate (100) may be exposed to the outside without being covered by the protective layer (800).

[0125] The concave portion (CP) of the substrate (100) can be provided concavely from one side of the substrate (100) toward the other side.

[0126] A concave portion (CP) can be formed by irradiating a laser onto one surface of the substrate (100). Accordingly, depending on the source of the irradiating laser, the shape of the vertical cross-section of the concave portion (CP) may be rectangular, or it may have a trapezoidal shape in which the width in the horizontal direction decreases from one surface to the other of the substrate (100).

[0127] At this time, the depth (T2) of the concave portion (CP) provided on one side of the substrate (100) may be smaller than the thickness (T1) of the substrate (100). That is, the concave portion (CP) provided on one side of the substrate (100) may not penetrate the substrate (100) along the thickness direction of the substrate (100).

[0128] The depth (T2) of the concave portion (CP) provided on one surface of the substrate (100) may satisfy a range of 20% to 60% of the thickness (T1) of the substrate (100). Preferably, the depth (T2) of the concave portion (CP) provided on one surface of the substrate (100) may satisfy a range of 25% to 55% of the thickness (T1) of the substrate (100). More preferably, the depth (T2) of the concave portion (CP) provided on one surface of the substrate (100) may satisfy a range of 30% to 50% of the thickness (T1) of the substrate (100).

[0129] If the depth (T2) of the concave portion (CP) provided on one side of the substrate (100) is less than 20% of the thickness (T1) of the substrate (100), the manufacturing information provided to the concave portion (CP) from the outside may not be easily identifiable, and accordingly, the concave portion (CP) of the substrate (100) may not function as a mark indicating manufacturing information.

[0130] Additionally, if the depth (T2) of the concave portion (CP) provided on one side of the substrate (100) exceeds 60% of the thickness (T1) of the substrate (100), the rigidity of the substrate (100) may be reduced, and the rigidity of the flexible circuit board (1000) may be reduced accordingly.

[0131] Additionally, according to the embodiment of FIG. 3, the flexible circuit board (1000) may include a filling portion (FP) that fills a recess (CP) provided in the substrate (100). The filling portion (FP) may be provided to fill the recess (CP) provided in the substrate (100). At this time, the filling portion (FP) may be provided with a material different from the material constituting the substrate (100). For example, the filling portion (FP) may include an insulating material, and the insulating material of the filling portion (FP) may be different from the insulating material of the substrate (100). For example, the color of the filling portion (FP) may be different from the color of the substrate (100). Accordingly, the embodiment can easily provide a mark corresponding to manufacturing information while preventing the rigidity of the flexible circuit board (1000) from being reduced by the recess (CP).

[0132]

[0133] Referring to FIG. 4, according to another embodiment, the flexible circuit board (1000) has a recess (CP). In this case, the recess (CP) may be provided in the dummy pattern portion (DP) of the flexible circuit board (1000). That is, if the recess (CP) is provided in the wiring pattern portion (WP), the signal transmission characteristics of the wiring pattern portion (WP) may be degraded, and thereby the signal transmission loss may increase.

[0134] Accordingly, the concave portion (CP) may be provided in the dummy pattern portion (DP) rather than the wiring pattern portion (WP). Additionally, a protective layer (800) is provided on one side of the substrate (100). Accordingly, when the concave portion (CP) is provided in the dummy pattern portion (DP), the concave portion (CP) may be provided in an area that does not overlap with the protective layer (800) along the thickness direction. For example, the concave portion (CP) may be provided in an area that overlaps with the open area (OR) of the protective layer (800) in the thickness direction. For example, the concave portion (CP) may be provided in an area on one side of the dummy pattern portion (DP) that is not covered by the protective layer (800). Accordingly, the concave portion (CP) provided in the dummy pattern portion (DP) may be exposed to the outside without being covered by the protective layer (800).

[0135] The concave portion (CP) of the dummy pattern portion (DP) can be provided concavely from one side of the dummy pattern portion (DP) toward the other side.

[0136] The concave portion (CP) can be formed by irradiating a laser onto one surface of the dummy pattern portion (DP). Accordingly, depending on the laser source used for irradiation, the vertical cross-sectional shape of the concave portion (CP) may be rectangular, or it may have a trapezoidal shape in which the width in the horizontal direction decreases from one surface to the other of the dummy pattern portion (DP).

[0137] At this time, the depth (T4) of the concave portion (CP) provided on one side of the dummy pattern portion (DP) may be smaller than the thickness (T3) of the dummy pattern portion (DP). That is, the concave portion (CP) provided on one side of the dummy pattern portion (DP) may not penetrate the dummy pattern portion (DP) along the thickness direction of the substrate (100).

[0138] The depth (T4) of the concave portion (CP) provided on one side of the dummy pattern portion (DP) can satisfy a range of 20% to 60% of the thickness (T3) of the dummy pattern portion (DP). Preferably, the depth (T4) of the concave portion (CP) provided on one side of the dummy pattern portion (DP) can satisfy a range of 25% to 55% of the thickness (T3) of the dummy pattern portion (DP). More preferably, the depth (T4) of the concave portion (CP) provided on one side of the dummy pattern portion (DP) can satisfy a range of 30% to 50% of the thickness (T3) of the dummy pattern portion (DP).

[0139] If the depth (T4) of the concave portion (CP) provided on one side of the dummy pattern portion (DP) is less than 20% of the thickness (T3) of the dummy pattern portion (DP), the manufacturing information provided to the concave portion (CP) from the outside may not be easily identifiable, and accordingly, the concave portion (CP) of the dummy pattern portion (DP) may not function as a mark indicating manufacturing information.

[0140] Additionally, if the depth (T4) of the concave portion (CP) provided on one side of the dummy pattern portion (DP) exceeds 60% of the thickness (T3) of the dummy pattern portion (DP), the dummy pattern portion (DP) may not function as a dummy portion, and the rigidity of the flexible circuit board (1000) may be reduced accordingly.

[0141] Additionally, according to the embodiment of FIG. 5, the flexible circuit board (1000) may include a filling portion (FP) that fills the recess (CP) provided in the dummy pattern portion (DP). The filling portion (FP) may be provided to fill the recess (CP) provided in the dummy pattern portion (DP). At this time, the filling portion (FP) may be provided with a material different from the material constituting the dummy pattern portion (DP). For example, the filling portion (FP) may include an insulating material or a metallic material. Also, if the filling portion (FP) is provided with a metallic material, the metallic material of the filling portion (FP) may be different from the metallic material of the dummy pattern portion (DP). For example, the color of the filling portion (FP) may be different from the color of the dummy pattern portion (DP). Accordingly, the embodiment can easily provide a mark corresponding to manufacturing information while preventing the rigidity of the flexible circuit board (1000) from being reduced by the recess (CP).

[0142]

[0143] Referring to FIG. 6, according to another embodiment, the flexible circuit board (1000) has a recess (CP). In this case, the recess (CP) may be provided in the protective layer (800) of the flexible circuit board (1000).

[0144] Accordingly, the recess (CP) may be provided in an area on one side of the protective layer (800) that does not overlap with the wiring pattern portion (WP) in the thickness direction. For example, the recess (CP) may be provided in an area on one side of the protective layer (800) that does not overlap with the wiring pattern portion (WP) and the dummy pattern portion (DP) in the thickness direction. Through this, the embodiment can solve the problem that the wiring pattern portion (WP) embedded within the protective layer (800) is not stably protected by the recess (CP) of the protective layer (800), and thereby further improve the signal transmission characteristics of the wiring pattern portion (WP).

[0145] Additionally, referring to FIG. 7, the concave portion (CP) may be provided in an area overlapping along the vertical direction of the conductive pattern portion on one side of the protective layer (800). In particular, the concave portion (CP) may be provided in an area overlapping in the thickness direction with the dummy pattern portion (DP) on one side of the protective layer (800). Through this, the embodiment makes it possible to form a concave portion (CP) for displaying manufacturing information on the protective layer (800) without affecting the signal transmission characteristics of the wiring pattern portion (WP).

[0146] The concave portion (CP) of the protective layer (800) may be provided concavely from one side of the protective layer (800) toward the other side. At this time, the concave portion (CP) of the protective layer (800) may not overlap with the wiring pattern portion (WP) and the dummy pattern portion (DP) along the horizontal direction. For example, the bottom surface of the concave portion (CP) of the protective layer (800) may be located between the upper surface of the protective layer (800) and the upper surface of the dummy pattern portion (DP).

[0147] A concave portion (CP) can be formed by irradiating a laser onto one surface of the protective layer (800). Accordingly, depending on the source of the irradiating laser, the shape of the vertical cross-section of the concave portion (CP) may be rectangular, or it may have a trapezoidal shape in which the width in the horizontal direction decreases from one surface to the other of the protective layer (800).

[0148] At this time, the depth (T6) of the concave portion (CP) provided on one side of the protective layer (800) may be smaller than the thickness (T5) of the protective layer (800). That is, the concave portion (CP) provided on one side of the protective layer (800) may not penetrate the protective layer (800) along the thickness direction of the substrate (100).

[0149] The depth (T6) of the concave portion (CP) provided on one side of the protective layer (800) may satisfy a range of 20% to 45% of the thickness (T5) of the protective layer (800). Preferably, the depth (T6) of the concave portion (CP) provided on one side of the protective layer (800) may satisfy a range of 25% to 42% of the thickness (T5) of the protective layer (800). More preferably, the depth (T6) of the concave portion (CP) provided on one side of the protective layer (800) may satisfy a range of 30% to 40% of the thickness (T5) of the protective layer (800).

[0150] If the depth (T6) of the concave portion (CP) provided on one side of the protective layer (800) is less than 20% of the thickness (T5) of the protective layer (800), the manufacturing information provided to the concave portion (CP) from the outside may not be easily identifiable, and accordingly, the concave portion (CP) of the protective layer (800) may not function as a mark indicating manufacturing information.

[0151] Additionally, if the depth (T6) of the recess (CP) provided on one side of the protective layer (800) exceeds 45% of the thickness (T3) of the protective layer (800), the recess (CP) may overlap horizontally with the wiring pattern portion (WP) or the dummy pattern portion (DP), and accordingly, the wiring pattern portion (WP) or the dummy pattern portion (DP) may not be reliably protected.

[0152]

[0153] Additionally, according to the embodiment of FIG. 8, the flexible circuit board (1000) may include a filling portion (FP) that fills the concave portion (CP) provided in the protective layer (800). The filling portion (FP) may be provided to fill the concave portion (CP) provided in the protective layer (800). At this time, the filling portion (FP) may be provided with a material different from the material constituting the protective layer (800). For example, the filling portion (FP) may include an insulating material. Also, the insulating material of the filling portion (FP) may be different from the insulating material of the protective layer (800). For example, the color of the filling portion (FP) may be different from the color of the protective layer (800). Accordingly, the embodiment can easily provide a mark corresponding to manufacturing information while preventing the rigidity of the flexible circuit board (1000) from being reduced by the concave portion (CP) of the protective layer (800).

[0154]

[0155] FIG. 9 is a plan view showing a flexible circuit board according to a second embodiment.

[0156] According to the embodiment of FIG. 9, the flexible circuit board (1000) may have a plurality of marks provided in a dummy pattern portion (DP).

[0157] At this time, referring to (A) of FIG. 9, the flexible circuit board (1000) may have a dummy pattern portion (DPM) provided on one side based on the chip mounting area (CHA), and the dummy pattern portion (DPM) may function as a first mark (DPM). That is, the first mark (DPM) may be a dummy pattern portion (DP) having a concave portion (CP) as shown in FIG. 4 or FIG. 5.

[0158] Additionally, referring to (B) of FIG. 9, the flexible circuit board (1000) may have a dummy pattern portion (DPL) provided on the other side relative to the chip mounting area (CHA). At this time, the dummy pattern portion (DPL) may function as a second mark (DPM). The second mark (DPM) may be a dummy pattern formed by patterning a metal layer. That is, the second mark (DPM) may be logo information that is applied equally to multiple products of the same module. And, the logo information is applied equally to multiple flexible circuit boards. Accordingly, the second mark (DPM) may be a dummy pattern patterned in an area that is not covered by the protective layer (800), unlike the first mark (DPM). For example, the second mark (DPM) may display logo information by forming a through hole rather than a concave part in the dummy pattern.

[0159]

[0160] FIGS. 10a and FIGS. 10b are schematic plan views of a flexible circuit board according to a third embodiment. Specifically, FIG. 10a is a schematic plan view of one side of a flexible circuit board according to a third embodiment with a protective layer removed, and FIG. 10b is a schematic plan view of one side of a flexible circuit board according to a third embodiment with a protective layer disposed thereon.

[0161] Referring to FIG. 10a and FIG. 10b, the flexible circuit board (1000A) according to the third embodiment may be a flexible circuit board for a connector. That is, the flexible circuit board (1000A) may connect between a display panel and an external circuit board. In this case, the chip may be placed on the external circuit board rather than on the flexible circuit board. In this case, the flexible circuit board (1000A) may simply function to electrically connect between the display panel and the external circuit board.

[0162] A flexible circuit board (1000A) includes a substrate (100), a wiring pattern portion (WP), a dummy pattern portion (DP), and a protective layer (800).

[0163] At this time, the wiring pattern portion (WP) may only have the third wiring pattern portion (400) described in the previous embodiment. That is, one end of the third wiring pattern portion (400) may be located within the second open area of ​​the protection layer (800) and the other end may be located within the third open area of ​​the protection layer (800). For example, one end of the third wiring pattern portion (400) may be connected to an external circuit board, and the other end of the third wiring pattern portion (400) may be connected to a display panel. That is, the third wiring pattern portion (400) may refer to a wiring pattern that electrically connects the external circuit board and the display panel.

[0164] Additionally, the dummy pattern section (DP) may include a second dummy pattern section (600) and a third dummy pattern section (700). One end of the second dummy pattern section (600) may be located in a second open area, and the other end may be covered by a protective layer (800). For example, one end of the second dummy pattern section (600) may be connected to a display panel, and the other end may not be electrically connected to other components. One end of the third dummy pattern section (700) may be located in a third open area, and the other end may be covered by a protective layer (800). For example, one end of the third dummy pattern section (700) may be connected to an external circuit board, and the other end may not be electrically connected to other components.

[0165] In addition, at least one of the substrate (100), dummy pattern portion (DP), and protective layer (800) of the flexible circuit board (1000A) may be provided with a concave portion (CP).

[0166]

[0167] FIGS. 11a and FIGS. 11b are plan views showing one side and the other side of a flexible circuit board according to the fourth embodiment, and FIG. 12 is a cross-sectional view showing a concave portion according to the eighth embodiment.

[0168] Referring to FIG. 11a and FIG. 11b, the flexible circuit board of the fourth embodiment may include a substrate (100), a wiring pattern portion (WP), a dummy pattern portion (DP), and a protective layer (800).

[0169] Additionally, the wiring pattern portion (WP), the dummy pattern portion (DP), and the protective layer (800) may each be provided on the first surface (1S) and the second surface (2S) opposite to the first surface (1S) of the substrate (100).

[0170] That is, the flexible circuit board of the third embodiment may be a double-sided flexible circuit board in which a wiring pattern portion (WP) and a dummy pattern portion (DP) are respectively disposed on the first surface (1S) and the second surface (2S) of the substrate (100).

[0171] Accordingly, each of the wiring pattern section (WP) and the dummy pattern section (DP) may include an upper wiring pattern section and an upper dummy pattern section disposed on the first surface (1S) of the substrate (100). Additionally, the wiring pattern section (WP) and the dummy pattern section (DP) may include a lower wiring pattern section and a lower dummy pattern section disposed on the second surface (2S) of the substrate (100).

[0172] That is, among the wiring pattern sections (WP) in FIG. 1a and FIG. 1b, the first wiring pattern section (200) and the third wiring pattern section (400) may include only the upper wiring pattern section, and the second wiring pattern section (300) may include the upper wiring pattern section and the lower wiring pattern section.

[0173] Also, FIGS. 11a and FIGS. 11b may illustrate the upper wiring pattern and the lower wiring pattern of the second wiring pattern section (300) arranged on the first surface (1S) and the second surface (2S) of the substrate (100).

[0174] The upper wiring of the second wiring pattern portion (300) disposed on the first surface (1S) of the substrate (100) may include a first via (V1) that penetrates the substrate (100) and is disposed in the chip mounting area (CHA). Additionally, the upper wiring may include a first upper wiring (301) that includes a pad directly connected to the first via (V1).

[0175] Additionally, the upper wiring of the second wiring pattern portion (300) may include a second upper wiring (303) that includes a connecting wiring extending toward one end of the first surface (1S) of the pad and the substrate (100) in the chip mounting area (CHA). And, a second via (V2) may be provided at the end of the second upper wiring (303).

[0176] Additionally, the lower wiring of the second wiring pattern section (300) is arranged on the second surface (2S) of the substrate (100). The lower wiring of the second surface (2S) may include a first lower wiring (302) connected to the first upper wiring (301) through a first via (V1). Additionally, the lower wiring of the second surface (2S) may include a second lower wiring (304) connected to the second upper wiring (302) through a second via (V2).

[0177] Additionally, a lower protective layer (800B) may be disposed on the second surface (2S) of the substrate (100). The lower protective layer (800B) includes an open area, thereby exposing a portion of the first lower wiring (302) and a portion of the second lower wiring (304). Additionally, the portion of the first lower wiring (302) and the portion of the second lower wiring (304) exposed through the open area of ​​the lower protective layer (800B) may function as a display panel connection pad connected to a display panel.

[0178] That is, unlike the first embodiment, the D-panel connection pad in the flexible circuit board (1000) of the second embodiment may be placed on the first surface (1S) of the substrate (100), and the display panel connection pad may be placed on the second surface (2S) of the substrate (100).

[0179] And, it may be provided in any one of the first surface (1S) of the substrate (100), the second surface (2S) of the substrate (100), the upper dummy pattern portion, the lower dummy pattern portion, the upper protective layer, and the lower protective layer described with reference to FIGS. 1a to 9.

[0180] At this time, in the case of a double-sided flexible circuit board, damage to the wiring pattern portion (WP) may occur during the process of forming the concave portion (CP). Therefore, the concave portion (CP) of the embodiment may not overlap along the thickness direction with the upper wiring pattern portion provided on the first surface (1S) of the substrate (100) as well as the lower wiring portion provided on the second surface (2S) of the substrate (100).

[0181] Referring to FIG. 12, the concave portion (CP) provided on the first surface (1S) of the substrate (100) may not overlap with the lower wiring pattern portion (WPB) placed on the second surface (2S) of the substrate (100) along the thickness direction. Preferably, the concave portion (CP) provided on the first surface (1S) of the substrate (100) may overlap with the lower dummy pattern portion (DPB) provided on the second surface (2S) of the substrate (100) along the thickness direction.

[0182] Additionally, when a concave portion (CP) is provided on the second surface (2S) of the substrate (100), the concave portion (CP) provided on the second surface (2S) of the substrate (100) may not overlap with the upper wiring pattern portion (WPA) provided on the first surface (1S) of the substrate (100) along the thickness direction. Additionally, the concave portion (CP) provided on the second surface (2S) of the substrate (100) may overlap with the upper dummy pattern portion provided on the first surface (1S) of the substrate (100) along the thickness direction.

[0183] By doing so, the embodiment can prevent damage to the wiring pattern portion that may occur due to the formation of the concave portion (CP), and thereby can display manufacturing information without degrading the physical reliability and / or electrical reliability of the flexible circuit board.

[0184] Furthermore, the concave portion (CP) provided in the upper dummy pattern portion may not overlap along the thickness direction with the lower wiring pattern portion disposed on the second surface (2S) of the substrate (100). Additionally, the concave portion provided in the lower dummy pattern portion may not overlap along the thickness direction with the upper wiring pattern portion disposed on the first surface (1S) of the substrate (100).

[0185]

[0186] FIG. 13 is a cross-sectional view showing the layer structure of a conductive pattern portion according to a first embodiment, and FIG. 14 describes the layer structure of a conductive pattern portion according to a second embodiment. Specifically, FIG. 13 and FIG. 14 may show the first-1 wiring pattern portion (210) among the wiring pattern portions (WP) of the conductive pattern portions (WP, DP). In addition, other wiring pattern portions excluding the first-1 wiring pattern portion (210) and the dummy pattern portion (DP) may also have a layer structure corresponding to the first-1 wiring pattern portion (210) described below.

[0187] Referring to FIG. 13, the first connection pattern (210T) and the first pad (210P1) of the first-1 wiring pattern section (210) include a buffer layer (215), a metal layer (211), and a bonding layer (213).

[0188] The buffer layer (215) may include multiple layers. Specifically, the buffer layer (215) includes a first buffer layer (215A) and a second buffer layer (215B). The first buffer layer (215A) is disposed on the substrate (100). The second buffer layer (215B) is disposed on the first buffer layer (215A).

[0189] The first buffer layer (215A) includes a material that has good adhesion to the substrate (100). For example, the first buffer layer (215A) may include nickel (Ni). Additionally, the second buffer layer (215B) includes a material that has good adhesion to the circuit pattern. For example, the second buffer layer (215B) may include chromium (Cr).

[0190] The buffer layer (215) may have a thin film thickness in the nanometer range. For example, the buffer layer (215) may have a thickness of 20 nm or less. The adhesion between the substrate (100) and the circuit pattern is improved by the buffer layer (215).

[0191] A metal layer (211) is disposed on a buffer layer (215). Specifically, the metal layer (211) is disposed on a second buffer layer (215B). The metal layer (211) comprises a metallic material. For example, the metal layer (211) may comprise copper (Cu).

[0192] The metal layer (211) can be formed by electroplating using a buffer layer as a seed layer. That is, the metal layer (211) can be a plating layer.

[0193] The thickness of the metal layer (211) may be 5 μm to 30 μm. A bonding layer (213) is disposed on the metal layer (211). The bonding layer (213) is disposed on the side and top surfaces of the metal layer (211). For example, the bonding layer (213) may be disposed while wrapping around the metal layer (211). The bonding layer (213) comprises a metal. For example, the bonding layer (213) may comprise tin (Sn). The bonding layer (213) is formed by a plating process. Specifically, the bonding layer (213) may be a plating layer.

[0194] The thickness of the bonding layer (213) may be 0.3 μm to 0.7 μm. The tin content may increase as it extends from the lower surface of the bonding layer (213) toward the upper surface. That is, the bonding layer (213) comes into contact with the metal layer (211). Therefore, the tin content increases as it goes from the lower surface of the bonding layer (213) toward the upper surface. In addition, the copper content decreases as it goes from the lower surface of the bonding layer (213) toward the upper surface.

[0195] Accordingly, pure tin may remain in a thickness range of 0.1 μm to 0.3 μm from the upper surface of the bonding layer (213). The pad portion can be easily bonded to the terminals of the chip, circuit board, and display panel by the bonding layer (213). For example, when heat and pressure are applied to the pad portion, the upper surface of the bonding layer melts. Pure tin remains on the upper surface of the bonding layer. Therefore, the pad portion is easily bonded to the terminals of the chip, circuit board, and display panel.

[0196] Referring to FIG. 14, the metal layer (211) may include a first metal layer (211A) and a second metal layer (211B). The first metal layer (211A) is disposed on a buffer layer (215). The second metal layer (211B) is disposed on the first metal layer (211A). The second metal layer (211B) may be formed by electroplating using the first metal layer (211A) as a seed layer. That is, the second metal layer (211B) may be a plating layer.

[0197] The thickness of the first metal layer (211A) may be smaller than the thickness of the second metal layer (211B).

[0198] For example, the thickness of the first metal layer (211A) may be 0.7 μm to 2 μm, and the thickness of the second metal layer (211B) may be 5 μm to 25 μm.

[0199] The first metal layer (211A) and the second metal layer (211B) may contain the same metal material. For example, the first metal layer (211A) and the second metal layer (211B) may contain copper (Cu).

[0200] The bonding layer (213) may include a first bonding layer (213A) and a second bonding layer (203b).

[0201] The first bonding layer (213A) is disposed on the metal layer (211). Specifically, the first bonding layer (213A) is disposed on the first connection pattern (210T), the first pad (210P1), and the second pad (210P2).

[0202] The second bonding layer (203b) is disposed on the first bonding layer (213A). Specifically, the second bonding layer (203b) is disposed on the first pad (210P1) and the second pad (210P2).

[0203] Accordingly, the first connection pattern (210T) includes a buffer layer (215), a metal layer (211), and a first bonding layer (213A). Additionally, the first pad (210P1) and the second pad (210P2) include a buffer layer (215), a metal layer (211), a first bonding layer (213A), and a second bonding layer (203b).

[0204] The first bonding layer (213A) and the second bonding layer (203b) comprise metal. Specifically, the first bonding layer (213A) and the second bonding layer (203b) may comprise tin (Sn).

[0205] The first bonding layer (213A) and the second bonding layer (203b) are arranged with different thicknesses. Specifically, the thickness of the second bonding layer (203b) is greater than the thickness of the first bonding layer (213A).

[0206] For example, the first bonding layer (213A) has a thickness of 0.02 μm to 0.06 μm. Also, the second bonding layer (203b) has a thickness of 0.2 μm to 0.6 μm.

[0207] Accordingly, the thickness of the first connection pattern (210T) is reduced. The flexible circuit board includes a bending region (BA) that is bent in one area. The first connection pattern (210T) is placed on the bending region (BA). Accordingly, the thickness of the bonding layer on the first connection pattern (210T) is formed to be small. As a result, when the flexible circuit board is bent, it is possible to prevent the formation of cracks in the first connection pattern (210T).

[0208] The thickness of the circuit pattern may be greater than 5㎛ and up to 25㎛. Specifically, the thickness of the circuit pattern may be 6㎛ to 20㎛. Specifically, the thickness of the circuit pattern may be 7㎛ to 15㎛.

[0209] If the thickness of the circuit pattern is less than 5㎛, the resistance of the circuit pattern may increase. If the thickness of the circuit pattern exceeds 25㎛, it becomes difficult to implement fine patterns.

[0210]

[0211] FIGS. 15 and 16 are drawings for explaining the connection between a COF module and other components according to an embodiment.

[0212] Referring to FIGS. 15 and 16, one end of the COF module (2000) is connected to the display panel (4000), and the other end is connected to the circuit board (3000).

[0213] Referring to FIG. 15, the display panel (4000) and the circuit board (3000) are placed on one side of the COF module (2000). That is, in the flexible circuit board according to the first embodiment, the display panel (4000) and the circuit board (3000) are placed on the same side of the COF module (2000).

[0214] Referring to FIG. 16, the display panel (4000) and the circuit board (3000) are placed on the other side of the COF module (2000). That is, in the flexible circuit board according to the second embodiment, the display panel (4000) and the circuit board (3000) are placed on the other side of the COF module (2000).

[0215] Since the COF module (2000) includes a flexible substrate, it has a rigid shape and a bent shape between the display panel (3000) and the circuit board (4000). That is, the COF module (2000) may include a bending region (BA).

[0216] The COF module (2000) connects the display panel (4000) and the circuit board (3000), which are positioned facing each other, in a curved shape. Accordingly, the thickness of the electronic device is reduced. In addition, the design freedom of the electronic device is improved. Furthermore, the wiring of the COF module (2000) is not broken even in a curved shape. Accordingly, the reliability of the electronic device is improved.

[0217] Since the above COF module is flexible, it can be used in various electronic devices.

[0218] FIGS. 17 to 19 are drawings relating to an electronic device including a flexible circuit board according to an embodiment.

[0219] For example, referring to FIG. 17, the COF module can be applied to a bendable flexible touch window. Thus, a touch device device including it may be a flexible touch device device. Thus, a user can bend or fold it with their hand. Such a flexible touch window can be applied to wearable touch devices, etc.

[0220] Referring to FIG. 18, the COF module can be applied to various wearable touch devices including curved displays. Accordingly, an electronic device including the COF module can be made slimmer or lighter.

[0221] Referring to FIG. 19, the COF module can be used in various electronic devices having a display part, such as TVs, monitors, and laptops. At this time, the COF module can also be used in electronic devices having a curved display part.

[0222]

[0223] The features, structures, effects, etc. described in the above-described embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified and implemented in other embodiments by a person skilled in the art to which the embodiments belong. Therefore, details regarding such combinations and modifications should be interpreted as being included within the scope of the present invention.

[0224] Furthermore, although the invention has been described above with reference to embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

1. Entry; A conductive pattern portion disposed on the above-mentioned substrate; and It includes a protective layer disposed on the above-mentioned substrate and comprising an open area, and At least one of the above-mentioned substrate, the above-mentioned conductive pattern portion, and the above-mentioned protective layer includes a concave portion provided concavely in the thickness direction of the above-mentioned substrate, and A flexible circuit board in which the above-mentioned concave portion does not penetrate at least one of the above-mentioned substrate, the above-mentioned wiring pattern portion, and the above-mentioned protective layer along the thickness direction.

2. In Paragraph 1, A flexible circuit board, wherein the above-mentioned concave portion is a laser mark indicating manufacturing history information of the flexible circuit board.

3. In Paragraph 1, The above description includes a first surface on which the conductive pattern portion and the protective layer are disposed, and a second surface opposite to the first surface on which the conductive pattern portion and the protective layer are not disposed. The conductive pattern portion includes a wiring pattern portion through which an effective signal is transmitted, and a dummy pattern portion having a different function from the wiring pattern portion. A flexible circuit board having at least one of the first surface of the substrate, the second surface of the substrate, the dummy pattern portion, and the protective layer.

4. In Paragraph 3, The above-mentioned concave portion is provided on the first surface of the above-mentioned material, and A flexible circuit board having a concave portion provided on the first surface of the above description that does not overlap with the wiring pattern portion and the dummy pattern portion along the thickness direction, but overlaps with the open area of ​​the protective layer along the thickness direction.

5. In Paragraph 3, The above-mentioned concave portion is provided on the second surface of the above-mentioned material, and A flexible circuit board having a concave portion provided on the second surface of the above description that does not overlap with the wiring pattern portion along the thickness direction.

6. In Paragraph 3, The above-mentioned concave portion is provided on one surface of the above-mentioned dummy pattern portion, and A flexible circuit board having a concave portion provided on one side of the above-mentioned dummy pattern portion that overlaps with the open area of ​​the protective layer along the thickness direction.

7. In Paragraph 3, The above-mentioned concave portion is provided on one surface of the above-mentioned protective layer, and A flexible circuit board having a recess provided on one surface of the protective layer that does not overlap with the wiring pattern along the thickness direction.

8. In Paragraph 1, The conductive pattern portion includes a wiring pattern portion through which an effective signal is transmitted, and a dummy pattern portion having a different function from the wiring pattern portion. The above description includes a first surface and a second surface opposite to the second surface, and The above wiring pattern portion includes an upper wiring pattern portion provided on the first surface of the above substrate and a lower wiring pattern portion provided on the second surface of the above substrate, and The above dummy pattern portion includes an upper dummy pattern portion provided on the first surface of the above substrate and a lower dummy pattern portion provided on the second surface of the above substrate, and The above protective layer includes an upper protective layer disposed on the first surface of the substrate and having an open area, and a lower protective layer disposed on the second surface of the substrate and having an open area. A flexible circuit board having at least one of the first surface of the substrate, the second surface of the substrate, the upper dummy pattern portion, the lower dummy pattern portion, the upper protective layer, and the lower protective layer.

9. In Paragraph 8, The above-mentioned concave portion includes at least one of a first concave portion provided on the first surface of the above-mentioned substrate and a second concave portion provided on the second surface of the above-mentioned substrate, and The first concave portion overlaps with the open area of ​​the upper protective layer along the thickness direction and does not overlap with the upper wiring pattern portion and the lower wiring pattern portion, A flexible circuit board in which the second concave portion overlaps with the open area of ​​the lower protective layer along the thickness direction and does not overlap with the upper wiring pattern portion and the lower wiring pattern portion.

10. In Paragraph 9, The first concave portion overlaps with the lower dummy pattern portion along the thickness direction, and A flexible circuit board in which the second concave portion overlaps the upper dummy pattern portion along the thickness direction.

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