Flexible circuit board modules and electronic devices including the same

Abstract

The flexible circuit board module according to the embodiment includes a first flexible circuit board and a second flexible circuit board, the first flexible circuit board including a substrate, a power supply pattern and a test pattern disposed on the substrate, and a protective layer disposed on the power supply pattern and the test pattern, the power supply pattern including a first wiring pattern, a 1-1 pad pattern and a 1-2 pad pattern, the 1-1 pad pattern being connected to a display panel and the 1-2 pad pattern being connected to a circuit board, and the first width of the first wiring pattern being 1 mm to 3 mm.

Description

Technical Field

[0001] The embodiments relate to a flexible circuit board module and an electronic device including the same.

Background Art

[0002] Recently, various electronic products have been made thinner, smaller, and lighter. Accordingly, various studies have been conducted to mount semiconductor chips at high density in a narrow area of an electronic product.

[0003] Chip On Film (COF) uses a flexible substrate. Accordingly, the COF can be applied to a flexible display. Also, the COF can achieve a fine pitch. Accordingly, a high-resolution display due to an increase in the number of pixels can be realized.

[0004] The COF mounts a semiconductor chip on a thin film-shaped flexible circuit board. For example, the semiconductor chip can be an Integrated Circuit (IC) chip or a Large Scale Integrated circuit (LSI) chip.

[0005] The chip can be connected to an external circuit board and a display panel via a circuit pattern. For example, pad portions are disposed at one end and the other end of the circuit pattern, respectively. One of the pad portions is electrically connected to a terminal of the chip. Also, the other one of the pad portions can be connected to terminals of the circuit board and the display panel. Accordingly, the chip, the circuit board, and the display panel are electrically connected via the COF. Accordingly, a signal can be transmitted to the display panel by the circuit pattern.

[0006] Furthermore, the COF includes a circuit pattern that supplies power to the circuit board or the display panel. Display panels that require high power require multiple power supply circuit patterns.

[0007] However, the space of the COF is limited. Also, if the COF includes multiple power supply circuit patterns, the size of the COF may become larger than the size of the display panel.

[0008] Therefore, there is a need for a new flexible circuit board module and electronic devices containing the same that can solve the problems described above.

[0009] As a patent related to the aforementioned flexible circuit board, Korean registered patent KR10-0618898 (2006.09.01) has been disclosed. [Overview of the project] [Problems that the invention aims to solve]

[0010] The embodiment provides a flexible circuit board module that can efficiently supply power to a large-area display panel. [Means for solving the problem]

[0011] The flexible circuit board module according to the embodiment includes a first flexible circuit board and a second flexible circuit board, the first flexible circuit board including a substrate, a power supply pattern and a test pattern disposed on the substrate, and a protective layer disposed on the power supply pattern and the test pattern, the power supply pattern including a first wiring pattern, a 1-1 pad pattern and a 1-2 pad pattern, the 1-1 pad pattern being connected to a display panel and the 1-2 pad pattern being connected to a circuit board, and the first width of the first wiring pattern being 1 mm to 3 mm. [Effects of the Invention]

[0012] The flexible circuit board module according to the embodiment includes a first flexible circuit board and a second flexible circuit board.

[0013] The first flexible circuit board includes a power supply pattern. The power supply pattern can stably supply power to the display panel.

[0014] The aforementioned power supply pattern is connected to multiple pad patterns. This improves the power supply efficiency of the power supply pattern.

[0015] Furthermore, the first flexible circuit board includes a test pattern. This test pattern allows the current flow of the first flexible circuit board to be verified before use. This improves the reliability of the electronic device.

[0016] Furthermore, the first flexible circuit board includes a first region and a second region. The first region is bendable. The layer structure of the wiring pattern overlapping the first region may differ from the layer structure of the other regions. This improves the bending reliability of the first flexible circuit board.

[0017] The second flexible circuit board may omit the power supply pattern. This may reduce the size of the second flexible circuit board. In addition, the uniformity of the patterns placed on the second flexible circuit board will be improved. [Brief explanation of the drawing]

[0018] [Figure 1] This is a plan view of an electronic device according to an embodiment. [Figure 2] This diagram shows the connection relationships of the electronic devices according to the embodiment. [Figure 3] This diagram shows the connection relationships of the electronic devices according to the embodiment. [Figure 4] This is a plan view of the first flexible circuit board according to the embodiment. [Figure 5] This is an enlarged view of area A in Figure 4. [Figure 6] This is an enlarged view of area B in Figure 4. [Figure 7] It is a cross-sectional view obtained by cutting the A-A' region of FIG. 4. [Figure 8] It is a cross-sectional view obtained by cutting the A-A' region of FIG. 4. [Figure 9] It is a cross-sectional view obtained by cutting the A-A' region of FIG. 4. [Figure 10] It is a cross-sectional view obtained by cutting the A-A' region of FIG. 4. [Figure 11] It is a cross-sectional view obtained by cutting the B-B' region of FIG. 4. [Figure 12] It is a cross-sectional view obtained by cutting C-C' of FIG. 4. [Figure 13] It is a cross-sectional view obtained by cutting the B-B' region of FIG. 4. [Figure 14] It is a cross-sectional view obtained by cutting C-C' of FIG. 4. [Figure 15] It is a cross-sectional view obtained by cutting the B-B' region of FIG. 4. [Figure 16] It is a cross-sectional view obtained by cutting C-C' of FIG. 4. [Figure 17] It is a cross-sectional view obtained by cutting the B-B' region of FIG. 4. [Figure 18] It is a cross-sectional view obtained by cutting C-C' of FIG. 4. [Figure 19] It is a plan view of the second flexible circuit board according to the embodiment. [Figure 20] It is another plan view of the second flexible circuit board according to the embodiment. [Figure 21] It is a view of the electronic device according to the embodiment. [Figure 22] It is a view of the electronic device according to the embodiment. [Figure 23] It is a view of the electronic device according to the embodiment.

Modes for Carrying Out the Invention

[0019] Desired embodiments of the present invention will be described in detail below with reference to the attached drawings. However, the technical concept of the present invention is not limited to the embodiments described, but can be realized in a variety of different forms, and within the scope of the technical concept of the present invention, one or more components can be selectively combined and substituted between embodiments.

[0020] Furthermore, unless otherwise clearly defined, terms used in the embodiments of the present invention (including technical and scientific terms) shall be interpreted as having meanings generally understood by those with ordinary skill in the art to which the present invention pertains, and commonly used terms, such as those defined in dictionaries, may be interpreted in consideration of their meaning in the context of the relevant art.

[0021] Furthermore, the terms used in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the invention. In this specification, singular terms may also include plural terms unless otherwise specified in the text, and when it is written "A and / or at least one of B, C," it may include one or more of all possible combinations of A, B, and C.

[0022] Furthermore, when describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc., can be used. Such terms are merely used to distinguish a component from other components, and the terminology does not determine the essence, order, or procedure of that component.

[0023] Furthermore, when it is stated that one component is “connected,” “joined,” or “connected” to another component, this may include not only cases where the component is directly connected, joined, or connected to the other component, but also cases where it is “connected,” “joined,” or “connected” by another component that lies between it and the other component.

[0024] Furthermore, when it is stated that something is formed or positioned "above or below" each component, "above or below" 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 positioned between the two components.

[0025] Furthermore, when expressed as "up" or "down," it can include not only the upward direction but also the downward direction, based on a single component.

[0026] Furthermore, in the following description, the first direction 1D is defined as the width direction of the flexible circuit board, and the second direction 2D is defined as the longitudinal direction of the flexible circuit board.

[0027] The following describes a flexible circuit board module and an electronic device including the same according to an embodiment, with reference to the drawings.

[0028] Referring to Figures 1 to 3, the electronic device 10 includes a flexible circuit board module 1000, a display panel 2000, and a circuit board 3000.

[0029] The display panel 2000 and the circuit board 3000 are connected. More specifically, the display panel 2000 and the circuit board 3000 are electrically connected by the flexible circuit board module 1000.

[0030] The display panel 2000 may include a display panel that requires high power.

[0031] The display panel 2000 may include a first panel 2100, a second panel 2200, and a plurality of light-emitting diodes 2300.

[0032] The second panel 2200 may be placed on the first panel 2100. The flexible circuit board module 1000 may be connected to at least one of the first panel 2100 and the second panel 2200.

[0033] The light-emitting diode 2300 may include a micro-LED. The light-emitting diode 2300 may be placed on the first panel 2100 or the second panel 2200. For example, the light-emitting diode 2300 may be placed on the upper part of the second panel 2200. The flexible circuit board module 100 may be connected to the second panel 2200. Alternatively, the light-emitting diode 2300 may be placed on the lower part of the first panel 2100. The flexible circuit board module 1000 may be connected to the second panel 2200. This may increase the area on which the light-emitting diode 2300 can be placed.

[0034] The circuit board 3000 may include a rigid material. For example, the circuit board 3000 may include a printed circuit board (PCB).

[0035] The flexible circuit board module 1000 includes a first flexible circuit board 1100 and a second flexible circuit board 1200.

[0036] The first flexible circuit board 1100 includes a plurality of power supply wirings. The first flexible circuit board 1100 supplies power to at least one of the display panel 2000 and the circuit board 3000.

[0037] The second flexible circuit board 1200 includes a chip CH. The second flexible circuit board 1200 transmits signals between the display panel 2000 and the circuit board 3000. The second flexible circuit board 1200 may include a plurality of power supply wirings. The second flexible circuit board 1200 can supply power to at least one of the display panel 2000 and the circuit board 3000. Alternatively, the second flexible circuit board 1200 may not include power supply wirings.

[0038] The first flexible circuit board 1100 will be described below with reference to Figures 4 to 12.

[0039] Referring to Figure 4, the first flexible circuit board 1100 includes a base material 100, a pattern, and a protective layer 400.

[0040] The substrate 100 includes a first surface 1S and a second surface 2S opposite to the first surface 1S. The pattern and the protective layer 400 may be arranged on the first surface 1S.

[0041] The substrate 100 includes a cutting line CL. The first flexible circuit board 1100 is cut along the cutting line CL. For example, the pattern and the protective layer 400 are first placed on the substrate 100. Then, the substrate 100 is cut along the cutting line CL.

[0042] The substrate 100 includes an effective region AA and an ineffective region UA. More specifically, the first surface 1S includes the effective region AA and the ineffective region UA.

[0043] The effective area AA and the ineffective area UA are separated by the cutting line CL. Specifically, the effective area AA is defined as the area inside the cutting line CL, and the ineffective area UA is defined as the area outside the cutting line CL.

[0044] The circuit pattern and the protective layer are arranged in the effective region AA. The dummy pattern and sprocket holes SH are arranged in the non-effective region UA. The dummy pattern increases the strength of the substrate 100. The flexible circuit board 1000 is wound and unwound in a roll-to-roll manner by the sprocket holes SH.

[0045] The substrate 100 includes a ductile material. For example, the substrate 100 may include polyimide (PI). However, the examples are not limited thereto. The substrate 100 may also include a polymeric material containing polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). As a result, the first flexible circuit board can be used in a variety of electronic devices, including curved display devices. For example, because the first flexible circuit board has excellent flexibility properties, it can be applied to wearable electronic devices.

[0046] The substrate 100 can have a thickness of 20 μm to 100 μm. For example, the substrate 100 can have a thickness of 25 μm to 50 μm. For example, the substrate 100 can have a thickness of 30 μm to 40 μm. If the thickness of the substrate 100 exceeds 100 μm, the overall thickness of the first flexible circuit board increases. Therefore, the flexibility characteristics of the first flexible circuit board may decrease. Also, if the thickness of the substrate 100 is less than 20 μm, the strength of the first flexible circuit board may decrease.

[0047] The circuit pattern and the protective layer 400 are arranged on the substrate 100. More specifically, the circuit pattern and the protective layer 400 are arranged on the first surface 1S. More specifically, the circuit pattern and the protective layer 400 are arranged on at least one of the effective region AA and the non-effective region UA.

[0048] The protective layer 400 may include solder paste. For example, the protective layer 400 may include solder paste containing a thermosetting resin, a thermoplastic resin, a filler, a curing agent, or a curing accelerator.

[0049] The circuit pattern includes a power supply pattern 200 and a test pattern 300.

[0050] The power supply pattern 200 includes a first wiring pattern 201, a first-first pad pattern 202a, and a first-second pad pattern 202b. The first wiring pattern 201, the first-first pad pattern 202a, and the first-second pad pattern 202b are made of the same material. The first wiring pattern 201, the first-first pad pattern 202a, and the first-second pad pattern 202b are formed integrally.

[0051] The first pad pattern 202a is positioned outside the protective layer 400. The first pad pattern 202a can be connected to the display panel 2000. This connects the first flexible circuit board 1100 to the display panel 2000.

[0052] The first and second pad patterns 202b are located outside the protective layer 400. The first and second pad patterns 202b can be connected to the circuit board 3000. This connects the first flexible circuit board 1100 to the circuit board 3000.

[0053] The first wiring pattern 201 is positioned between the 1-1 pad pattern 202a and the 1-2 pad pattern 202b. The first wiring pattern 201 connects the 1-1 pad pattern 202a and the 1-2 pad pattern 202b. The first wiring pattern 201 is a pattern through which current flows. As a result, power is supplied to the display panel 2000 and the circuit board 3000 by the first wiring pattern 201.

[0054] Figure 5 is an enlarged view of area A in Figure 4. Figure 5(a) shows the area with the protective layer 400 omitted, and Figure 5(b) shows the area with the protective layer 400.

[0055] Referring to Figure 5, one first wiring pattern 201 can be connected to multiple first-first pad patterns 202a. This improves the efficiency of the current flowing to the display panel 2000.

[0056] In detail, since multiple first-first pad patterns 202a are integrated into a single first wiring pattern 201, the area over which current can move can be increased. In addition, the uniformity of the current moving across the multiple first-first pad patterns 202a can be improved. Therefore, the current transfer efficiency of the first flexible circuit board 1100 can be improved.

[0057] The first wiring pattern 201 is formed with a set width. More specifically, the width W1 of the first wiring pattern 201 may be 1 mm or more. More specifically, the width W1 of the first wiring pattern 201 may be 1 mm to 3 mm, 1.1 mm to 2.5 mm, or 1.3 mm to 2 mm.

[0058] If the width W1 of the first wiring pattern 201 is less than 1 mm, the number of integrated first-first pad patterns 202a decreases. This can reduce the current transfer efficiency of the first flexible circuit board. Also, the number of first wiring patterns 201 placed on the substrate 100 increases. As the number of first wiring patterns 201 increases, the spacing between the first wiring patterns 201 also increases. This can increase the size of the first flexible circuit board.

[0059] When the width W1 of the first wiring pattern 201 exceeds 3 mm, the number of integrated 1-1 pad patterns 202a increases. This allows 1-1 pad patterns 202a that are transmitted to different regions to be integrated into a single first wiring pattern 201. This can lead to interference of currents transmitted to different regions.

[0060] The first-first pad pattern 202a is formed with a set width. The first-first pad pattern 202a has a second-first width W2-1 and a second-second width W2-2. The second-first width W2-1 is the long width of the first-first pad pattern 202a. The second-first width W2-1 may be 15 μm or more. More specifically, the second-first width W2-1 may be 15 μm to 25 μm, 17 μm to 23 μm, or 19 μm to 21 μm.

[0061] The first-1 pad pattern 202a can be integrated with a plurality of first-1 pad patterns 202a such that the first wiring pattern 201 satisfies the width range.

[0062] The second-second width W2-2 is the short width of the first-first pad pattern 202a. The second-second width W2-2 may be 5 μm or more. More specifically, the second-second width W2-2 may be 3 μm to 14 μm, 5 μm to 13 μm, or 7 μm to 12 μm.

[0063] The power supply pattern 200 is cut by the cutting line CL. More specifically, a region of the first-1 pad pattern 202a is cut by the cutting line CL. The first-1 pad pattern 202a includes a narrow region. This allows the first-1 pad pattern 202a to be easily cut along the cutting line CL.

[0064] Figure 6 is an enlarged view of area B in Figure 4. Figure 6(a) shows the area with the protective layer 400 omitted, and Figure 6(b) shows the area with the protective layer 400.

[0065] Referring to Figure 6, one first wiring pattern 201 can be connected to multiple first- and second pad patterns 202b. This improves the efficiency of the current flowing to the circuit board 1000. Therefore, one first wiring pattern 201 can be connected to multiple first- and first-first pad patterns 202a and multiple first- and second pad patterns 202b. The number of first- and first-first pad patterns 202a connected to the first wiring pattern 201 is different from the number of first- and second pad patterns 202b connected to the first wiring pattern 201. In particular, the number of first- and first-first pad patterns 202a connected to the first wiring pattern 201 may be greater than the number of first- and second pad patterns 202b connected to the first wiring pattern 201.

[0066] In detail, since multiple first- and second pad patterns 202b are integrated into a single first wiring pattern 201, the area over which current can move can be increased. In addition, the uniformity of the current moving across the multiple first- and second pad patterns 202b can be improved. Therefore, the current transfer efficiency of the first flexible circuit board 1100 can be improved.

[0067] The first- and second pad patterns 202b are formed with a set width. The first- and second pad patterns 202b have a third width W3. The third width W3 is greater than the second-first width W2-1. In particular, the third width W3 may be 100 μm or more. In particular, the third width W3 may be 100 μm to 180 μm, 120 μm to 170 μm, or 130 μm to 150 μm.

[0068] The first- and second pad patterns 202b can be combined by a plurality of first- and second pad patterns 202b such that the first wiring pattern 201 satisfies the width range.

[0069] The test pattern 300 is positioned on the edge of the substrate 100. More specifically, the test pattern 300 is positioned on the edge of the substrate 100 in the second direction 2D.

[0070] The test pattern 300 includes a second wiring pattern 301, a second-first pad pattern 302a, and a second-second pad pattern 302b. The second wiring pattern 301, the second-first pad pattern 302a, and the second-second pad pattern 302b are made of the same material. The second wiring pattern 301, the second-first pad pattern 302a, and the second-second pad pattern 302b are formed integrally.

[0071] The second-first pad pattern 302a is positioned outside the protective layer 400. The second-first pad pattern 302a can be connected to the display panel 2000. This connects the test pattern 300 to the display panel 2000.

[0072] The second-second pad pattern 302b is located outside the protective layer 400. The second-second pad pattern 302b can be connected to the circuit board 3000. This connects the test pattern 300 to the circuit board 3000.

[0073] The second wiring pattern 301 is connected to at least one of the pad patterns of the second-first pad pattern 302a and the second-second pad pattern 302b. The second wiring pattern 301 is a pattern through which current flows.

[0074] The test pattern 300 may include at least three patterns. For example, the test pattern 300 may include a first test pattern 310, a second test pattern 320, and a third test pattern 330.

[0075] At least one of the first test pattern 310, the second test pattern 320, and the third test pattern 330 can be connected to at least one of the display panel 2000 and the circuit board 3000.

[0076] For example, the first test pattern 310 and the second test pattern 320 are connected to the display panel 2000 and the circuit board 3000. More specifically, the second wiring pattern of the first test pattern 310 and the second wiring pattern of the second test pattern 320 are connected to the 2-1 pad pattern 302a and the 2-2 pad pattern 302b. That is, the first test pattern 310 and the second test pattern 320 include the second wiring pattern, the 2-1 pad pattern 302a, and the 2-2 pad pattern 302b.

[0077] Furthermore, the third test pattern 330 is connected to either the display panel 2000 or the circuit board 3000. More specifically, the third test pattern 330 is connected to the display panel 2000. More specifically, the second wiring pattern of the third test pattern 330 is connected to the 2-1 pad pattern 302a. That is, the third test pattern 330 includes the second wiring pattern and the 2-1 pad pattern 302a.

[0078] The current flow on the first flexible circuit board 1100 can be confirmed by the test pattern 300.

[0079] For example, when transmitting current from the first flexible circuit board 1100 to the display panel 2000 and the circuit board 3000, the flow of current can be confirmed using the first test pattern 310 and the second test pattern 320.

[0080] Alternatively, when transmitting current from the first flexible circuit board 1100 to the circuit board 3000, the flow of current can be confirmed using the first test pattern 310 and the second test pattern 320.

[0081] Alternatively, when transmitting current from the first flexible circuit board 1100 to the display panel 2000, the current flow can be confirmed using the third test pattern 330.

[0082] This may improve the current-carrying efficiency of the first flexible circuit board 1100.

[0083] Figures 7 to 10 are various cross-sectional views obtained by cutting the A-A' region in Figure 4.

[0084] Referring to Figure 7, the power supply pattern 200 and the test pattern 300 contain metal. The power supply pattern 200 and the test pattern 300 contain the same material. Therefore, the following description will focus on the power supply pattern 200. The contents described below also apply to the test pattern 300.

[0085] Referring to Figure 7, the power supply pattern 200 may be formed in multiple layers. The first wiring pattern 201, the 1-1 pad pattern 202a, and the 1-2 pad pattern 202b may include a first metal layer 261 and a second metal layer 262.

[0086] The first metal layer 261 may be a seed layer for the power supply pattern 200. For example, the first metal layer 261 may contain copper (Cu) and be formed by electroless plating.

[0087] Furthermore, the second metal layer 262 may be a plated layer. For example, the second metal layer 262 may be a plated layer formed by electroplating with the first metal layer 261 as a seed layer.

[0088] The thickness of the first metal layer 261 may be less than the thickness of the second metal layer 262.

[0089] For example, the thickness of the first metal layer 261 may be 0.7 μm to 2 μm. Also, the thickness of the second metal layer 262 may be 10 μm to 25 μm.

[0090] The first metal layer 261 and the second metal layer 262 may contain the same metallic substance. For example, the first metal layer 261 and the second metal layer 262 may contain copper (Cu).

[0091] Furthermore, a bonding layer 263 may be placed on the second metal layer 261. The bonding layer 263 may be placed on at least one of the following surfaces: the side surface of the first metal layer 261, the side surface of the second metal layer 262, and the top surface of the second metal layer 262. For example, the bonding layer 263 for the first wiring pattern 201 and the 1-1 pad pattern 202a is placed on the top surface of the second metal layer 262. Also, the bonding layer 263 for the 1-2 pad pattern 202b is placed on the side surface of the first metal layer 261, the side surface of the second metal layer 262, and the top surface of the second metal layer 262.

[0092] The bonding layer 263 may contain a metal. More specifically, the bonding layer 263 may contain tin (Sn).

[0093] The bonding layer 263 may be formed with a thickness of 0.3 μm to 0.7 μm. The tin content of the bonding layer 263 may increase as it extends from the lower surface towards the upper surface.

[0094] In other words, the bonding layer 263 is positioned in contact with the second metal layer 262. Therefore, the tin content of the bonding layer 263 may increase and the copper content may decrease as you move from the lower surface towards the upper surface.

[0095] As a result, only pure tin can remain in the upper surface of the bonding layer 263 within a thickness range of 0.1 μm to 0.3 μm.

[0096] The bonding layer 263 allows the first-1 pad pattern 202a and the first-2 pad pattern 202b to be easily connected to the terminals of the display panel and the terminals of the circuit board. That is, when heat and pressure are applied to the pad patterns, the upper surface of the bonding layer, where pure tin remains, melts. As a result, the pad patterns, the terminals of the display panel, and the terminals of the circuit board can be easily bonded together.

[0097] The thickness of the power supply pattern 200 may be 2 μm to 25 μm. For example, the thickness of the power supply pattern 200 may be 5 μm to 20 μm. For example, the thickness of the power supply pattern 200 may be 7 μm to 15 μm.

[0098] If the thickness of the power supply pattern 200 is less than 2 μm, the resistance of the power supply pattern 200 may increase. If the thickness of the power supply pattern 200 exceeds 25 μm, it may become difficult to realize a fine pattern.

[0099] The power supply pattern 200 may further include a buffer layer 250. The buffer layer 250 is disposed between the substrate 100 and the first metal layer 261. The buffer layer 250 can improve the adhesion between the substrate 100 and the power supply pattern 200.

[0100] The buffer layer 250 may be formed in multiple layers. More specifically, a first buffer layer 251 and a second buffer layer 252 on the first buffer layer 251 may be arranged on the substrate 100. This allows the first buffer layer 251 to come into contact with the substrate 100, and the second buffer layer 252 to come into contact with the first metal layer 261.

[0101] The first buffer layer 251 may contain a material that has good adhesion to the substrate 100. For example, the first buffer layer 251 may contain nickel (Ni). The second buffer layer 252 may contain a material that has good adhesion to the metal layer. For example, the second buffer layer 252 may contain chromium (Cr).

[0102] The buffer layer 250 may have a thin film thickness in the nanometer range. For example, the thickness of the buffer layer 250 may be 20 nm or less.

[0103] The buffer layer 250 can improve the adhesion between the substrate 100 and the metal layer. This prevents the power supply pattern from peeling off.

[0104] Referring to Figure 4, the first flexible circuit board 1100 may have a first region 1A and a second region 2A defined.

[0105] The first region 1A and the second region 2A are defined as regions in which the power supply pattern 200 and the test pattern 300 extend in a straight line. More specifically, the first region 1A and the second region 2A are defined as regions in which the first wiring pattern 201 and the second wiring pattern 301 extend in a first direction 1D.

[0106] The first region 1A is adjacent to the first-1 pad pattern 202a and the second-1 pad pattern 302a. The second region 2A is adjacent to the first-2 pad pattern 202b and the second-2 pad pattern 302b.

[0107] The first flexible circuit board 1100 can be bent in at least one of the first region 1A and the second region 2A. More specifically, one region of the first region 1A can be bent. That is, the first region 1A can include a bending region.

[0108] As a result, stress may be generated in the first region 1A. In addition, one region of the first wiring pattern 201 or one region of the second wiring pattern 301 may overlap with the bending region.

[0109] Therefore, if the thickness of one region of the first wiring pattern 201 or one region of the second wiring pattern 301 that overlaps with the bending region is thick, the bending characteristics may deteriorate.

[0110] Furthermore, a crack may be formed in a region of the first wiring pattern 201 or a region of the second wiring pattern 301 that overlaps with the bending region due to the stress.

[0111] As a result, the layer structure of the wiring pattern may differ from the layer structure of the pad pattern.

[0112] Alternatively, the layer structure of one region of the wiring pattern that overlaps with the bending region may differ from the layer structure of other regions.

[0113] The power supply pattern 200 and the test pattern 300 contain the same substance. Therefore, the following description will focus on the power supply pattern 200. The information described below also applies to the test pattern 300.

[0114] Referring to Figure 8, a first flexible circuit board according to another embodiment will be described.

[0115] Referring to Figure 8, the bonding layer 263 can include multiple bonding layers. For example, the bonding layer 263 can include a first bonding layer 263a and a second bonding layer 263b.

[0116] More specifically, the first wiring pattern 201, the 1-1 pad pattern 202a, and the 1-2 pad pattern 202b may include the first bonding layer 263a. Furthermore, the 1-1 pad pattern 202a and the 1-2 pad pattern 202b may include the second bonding layer 263b.

[0117] The first bonding layer 263a and the second bonding layer 263b may contain a metal. The first bonding layer 263a and the second bonding layer 263b may contain the same metal. More specifically, the first bonding layer 263a and the second bonding layer 263b may contain tin (Sn).

[0118] The thickness of the first bonding layer 263a and the thickness of the second bonding layer 263b may be different. More specifically, the thickness of the first bonding layer 263a may be less than the thickness of the second bonding layer 263b.

[0119] For example, the thickness of the first bonding layer 263a may be 0.02 μm to 0.06 μm. Also, the thickness of the second bonding layer 263b may be 0.2 μm to 0.6 μm.

[0120] As a result, the thickness of the bonding layer placed on the wiring pattern is smaller than the thickness of the pad pattern placed on the pad pattern. In other words, the bonding layer placed on the wiring pattern is formed with the thickness of a thin film.

[0121] The first region 1A overlaps with the wiring pattern. Furthermore, only the first bonding layer is placed on the wiring pattern.

[0122] Therefore, the first flexible circuit board can be easily bent. Furthermore, when bending the first flexible circuit board, it is possible to prevent the formation of cracks in the bonding layer in the area overlapping with the bending area.

[0123] Referring to Figure 9, a first flexible circuit board according to another embodiment will be described.

[0124] Referring to Figure 9, the first wiring pattern 201 may include the first bonding layer 263a and the second bonding layer 263b.

[0125] The first bonding layer 263a is disposed on the metal layers 261 and 262. More specifically, the first bonding layer 263a is disposed on the upper and side surfaces of the metal layers 261 and 262. The first bonding layer 263a is disposed over a portion of the metal layers 261 and 262. The first bonding layer 263a is disposed so as to partially expose the metal layers 261 and 262. As a result, an open region OA is formed on the metal layers 261 and 262.

[0126] The open region OA is located in the region corresponding to the first region 1A. For example, the open region OA is located in the region that is all or partly corresponding to the first region 1A.

[0127] A protective layer 400 is placed on the first bonding layer 263a. The protective layer 400 is placed inside the open area OA. As a result, the open area OA is filled with the protective layer 400.

[0128] The second bonding layer 263b is placed on the first bonding layer 263a. The second bonding layer 263b is placed on the upper and side surfaces of the first bonding layer 263a. That is, the second bonding layer 263b is not placed on the area corresponding to the open area OA.

[0129] The first wiring pattern 201 in the first region 1A includes an open region OA. A protective layer 400 containing a resin material is placed inside the open region OA.

[0130] Therefore, the first flexible circuit board can be easily bent. Furthermore, when bending the first flexible circuit board, the open region prevents cracks from forming in the bonding layer. That is, the first region includes the open region, and no bonding layer is placed in the open region. Therefore, when bending the first flexible circuit board, the stress prevents cracks from forming in the bonding layer.

[0131] Referring to Figure 10, a first flexible circuit board according to another embodiment will be described.

[0132] Referring to Figure 10, the first wiring pattern 201 may include the first bonding layer 263a and the second bonding layer 263b.

[0133] The first bonding layer 263a is disposed on the metal layers 261 and 262. More specifically, the first bonding layer 263a is disposed on the upper and side surfaces of the metal layers 261 and 262. The first bonding layer 263a is disposed so as to partially expose the metal layers 261 and 262. As a result, an open region OA is formed on the metal layers 261 and 262.

[0134] A first protective layer 410 is placed on the open area OA. The first protective layer 410 is placed inside the open area OA. The first protective layer 410 is in contact with the upper surfaces of the metal layers 261 and 262. As a result, the open area OA is filled with the protective layer 400.

[0135] The second bonding layer 263b is placed on the first bonding layer 263a. The second bonding layer 263b is placed on the upper and side surfaces of the first bonding layer 263a.

[0136] The second protective layer 420 is placed on the first bonding layer 263a. The second protective layer 420 is placed on the first protective layer 410. The second protective layer 420 overlaps with the open area OA.

[0137] The first wiring pattern 201 includes the open region OA. Inside the open region OA, the first protective layer 410 and the second protective layer 420, which contain a resin material, are arranged.

[0138] Therefore, the first flexible circuit board can be easily bent. Furthermore, when bending the first flexible circuit board, the open region can prevent cracks from forming in the bonding layer. That is, the first region includes the open region, and no bonding layer is placed in the open region. In addition, two protective layers are placed in the open region. Therefore, when bending the first flexible circuit board, it is possible to prevent cracks from forming in the bonding layer due to stress.

[0139] Figures 11 to 18 are cross-sectional views of the first flexible circuit board having the layer structure shown in Figures 7 to 10.

[0140] Figures 11 and 12 are cross-sectional views of the layered structure shown in Figure 7. Figures 13 and 14 are cross-sectional views of the layered structure shown in Figure 8. Figures 15 and 16 are cross-sectional views of the layered structure shown in Figure 9. Figures 17 and 18 are cross-sectional views of the layered structure shown in Figure 10.

[0141] Figures 11, 13, 15, and 17 are cross-sectional views of regions other than the first region, while Figures 12, 14, 16, and 18 are cross-sectional views of the first region.

[0142] Referring to Figures 11 and 12, the layer structure of the first region and the regions other than the first region may be the same. More specifically, the bonding layer 263 and the protective layer 400 may be arranged on the second metal layer 262 in the first region and the regions other than the first region.

[0143] Referring to Figures 13 and 14, the layer structure of the first region and the regions other than the first region may be the same. More specifically, the first bonding layer 263a and the protective layer 400 may be arranged on the second metal layer 262 in the first region and the regions other than the first region. More specifically, the thickness of the first bonding layer 263a is less than the thickness of the second bonding layer 263b, and the second bonding layer 263b may be arranged only on the 1-1 pad pattern 202a and the 1-2 pad pattern 202b.

[0144] Referring to Figures 15 and 16, the layer structure of the first region and the region other than the first region may differ. Referring to Figure 15, the first bonding layer 263a and the protective layer 400 may be placed on the second metal layer 262 in the region other than the first region. Referring to Figure 16, the protective layer 400 may be placed on the second metal layer 262. In detail, the thickness of the first bonding layer 263a and the thickness of the second bonding layer 263b are the same or similar, and the first bonding layer 263a may be placed on the region other than the first region. Furthermore, the second bonding layer 263b may be placed only on the 1-1 pad pattern 202a and the 1-2 pad pattern 202b.

[0145] Referring to Figures 17 and 18, the layer structure of the first region and the regions other than the first region may differ. Referring to Figure 17, the first bonding layer 263a and the second protective layer 420 may be placed on the second metal layer 262 in the regions other than the first region. Referring to Figure 18, the first protective layer 410 and the second protective layer 420 may be placed on the second metal layer 262. In detail, the thickness of the first bonding layer 263a and the thickness of the second bonding layer 263b are the same or similar, and the first bonding layer 263a may be placed on regions other than the first region. The second bonding layer 263b may be placed only on the 1-1 pad pattern 202a and the 1-2 pad pattern 202b. The second protective layer 420 is placed on the first region.

[0146] The second flexible circuit board 1200 will be described below with reference to Figures 19 and 20.

[0147] The second flexible circuit board 1200 includes a base material 100, a circuit pattern, a chip CH, and a protective layer 400.

[0148] The substrate 100 includes a first surface 1S and a second surface 2S opposite to the first surface 1S. The circuit pattern and the protective layer 400 are arranged on the first surface 1S.

[0149] The substrate 100 includes a cutting line CL. The first flexible circuit board 1100 is cut along the cutting line CL. For example, the circuit pattern and the protective layer 400 are first placed on the substrate 100. Then, the substrate 100 is cut along the cutting line CL.

[0150] The substrate 100 includes an effective region AA and an ineffective region UA. More specifically, the first surface 1S includes the effective region AA and the ineffective region UA.

[0151] The effective area AA and the ineffective area UA are separated by the cutting line CL. Specifically, the effective area AA is defined as the area inside the cutting line CL, and the ineffective area UA is defined as the area outside the cutting line CL.

[0152] The circuit pattern and the protective layer are arranged in the effective region AA. The dummy pattern and sprocket holes SH are arranged in the non-effective region UA. The dummy pattern increases the strength of the substrate 100. The flexible circuit board 1000 is wound and unwound in a roll-to-roll manner by the sprocket holes SH.

[0153] The substrate 100 includes a chip mounting area CHA. The chip mounting area CHA is placed on the first surface 1S. The chip mounting area CHA is located inside the effective area AA. The chip CH is placed in the chip mounting area CHA. The pad portion of the circuit pattern is located inside the chip mounting area CHA. The protective layer is not placed on the chip mounting area CHA.

[0154] The material and thickness of the base material 100 are the same as those of the first flexible circuit board. Therefore, a further explanation of this is omitted.

[0155] The circuit pattern and the protective layer 400 are arranged on the substrate 100. More specifically, the circuit pattern and the protective layer 400 are arranged on the first surface 1S. More specifically, the circuit pattern and the protective layer 400 are arranged on at least one of the effective region AA and the non-effective region UA.

[0156] The circuit pattern includes at least one of the first circuit pattern 210, the second circuit pattern 220, and the third circuit pattern 230.

[0157] Referring to Figure 19, the second flexible circuit board 1200 includes the first circuit pattern 210 and the second circuit pattern 220.

[0158] The first circuit pattern 210 includes a first wiring portion 211, a first pad portion 212a, and a second pad portion 212b. The first wiring portion 211, the first pad portion 212a, and the second pad portion 212b may be made of the same material. Furthermore, the first wiring portion 211, the first pad portion 212a, and the second pad portion 212b may be formed integrally.

[0159] The first pad portion 212a is positioned inside the chip mounting area CHA. This allows the first pad portion 212a to be connected to the terminals of the chip. This allows the first circuit pattern 210 to be connected to the chip.

[0160] Furthermore, the second pad portion 212b is located outside the chip mounting area CHA. The second pad portion 212b can be connected to the display panel 2000. This allows the first circuit pattern 210 to be connected to the display panel 2000.

[0161] Furthermore, the first wiring section 211 is positioned between the first pad section 212a and the second pad section 212b. That is, the first wiring section 211 connects the first pad section 212a and the second pad section 212b. This connects the chip CH and the display panel 2000. Therefore, signals generated by the chip CH are transmitted to the display panel 2000.

[0162] The first circuit pattern 210 may include a test pad section. More specifically, a first test pad section TP1 is located in the non-effective region UA. The first wiring section 211, the first pad section 212a, the second pad section 212b, and the first test pad section TP1 may be formed integrally.

[0163] The first circuit pattern 210 can be tested before connecting the circuit board and the second pad portion 212b. For example, the presence or absence of open and short circuits in the first circuit pattern can be checked via the first test pad portion TP1.

[0164] The second circuit pattern 220 includes a second wiring portion 221, a third pad portion 222a, and a fourth pad portion 222b. The second wiring portion 221, the third pad portion 222a, and the fourth pad portion 222b may be made of the same material. Furthermore, the second wiring portion 221, the third pad portion 222a, and the fourth pad portion 222b may be formed integrally.

[0165] The third pad portion 222a is located inside the chip mounting area CHA. This allows the third pad portion 222a to be connected to the terminals of the chip CH. This allows the second circuit pattern 220 to be connected to the chip CH.

[0166] Furthermore, the fourth pad portion 222b is located outside the chip mounting area CHA. The fourth pad portion 222b can be connected to the circuit board 3000. This allows the second circuit pattern 220 and the circuit board 3000 to be connected.

[0167] Furthermore, the second wiring section 221 is positioned between the third pad section 222a and the fourth pad section 222b. That is, the second wiring section 221 connects the third pad section 222a and the fourth pad section 222b. This connects the chip CH and the circuit board 3000. Therefore, signals generated from the chip are transmitted to the circuit board 3000.

[0168] The second circuit pattern 220 may further include a test pad section. More specifically, a second test pad section TP2 is located in the non-effective region UA. The second wiring section 221, the third pad section 222a, the fourth pad section 222b, and the second test pad section TP2 may be formed integrally.

[0169] The second circuit pattern 220 can be tested before connecting the circuit board to the fourth pad portion 222b. For example, the presence or absence of open and short circuits in the second circuit pattern can be checked through the second test pad portion TP2.

[0170] The third circuit pattern 230 includes a third wiring portion 231, a fifth pad portion 232a, and a sixth pad portion 232b. The third wiring portion 231, the fifth pad portion 232a, and the sixth pad portion 232b may be made of the same material. Furthermore, the third wiring portion 231, the fifth pad portion 232a, and the sixth pad portion 232b may be formed integrally.

[0171] The fifth pad portion 232a and the sixth pad portion 232b are located outside the chip mounting area CHA. The fifth pad portion 232a may be connected to the display panel 2000. The sixth pad portion 232b may be connected to the circuit board 2000.

[0172] Furthermore, the third wiring section 231 is positioned between the fifth pad section 232a and the sixth pad section 232b. That is, the third wiring section 231 connects the fifth pad section 232a and the sixth pad section 232b. This connects the circuit board and the display panel.

[0173] The third circuit pattern 230 performs the same function as the power supply pattern of the first flexible circuit board 1110. That is, the third circuit pattern 230 can supply power to at least one of the display panel and the circuit board.

[0174] The line width and spacing of the third circuit pattern 230 may be greater than those of the first circuit pattern 210. Furthermore, the line width and spacing of the third circuit pattern 230 may be greater than those of the second circuit pattern 220.

[0175] Furthermore, the width of the third wiring section 231 is different from the width of the first wiring pattern. More specifically, the width of the third wiring section 231 is smaller than the width of the first wiring pattern. The second flexible circuit board 1200 includes the chip CH. The second flexible circuit board 1200 also includes the first circuit pattern 210 and the second circuit pattern 220 which are connected to the chip CH.

[0176] This limits the area in which the third wiring section 231 is placed. As a result, the width of the third wiring section 231 is smaller than the width of the first wiring pattern.

[0177] The protective layer 400 is placed on the first surface 1S. As a result, the protective layer 400 is placed on the first circuit pattern 210, the second circuit pattern 220, and the third circuit pattern 230. The protective layer 400 is placed in the area excluding the first pad portion 212a, the second pad portion 212b, the third pad portion 222a, the fourth pad portion 222b, the fifth pad portion 232a, and the sixth pad portion 232b.

[0178] Referring to Figure 20, the second flexible circuit board 1200 does not include the third circuit pattern 230. More specifically, the second flexible circuit board 1200 does not include patterns for supplying power to the display panel 2000 and / or the circuit board 3000.

[0179] This may reduce the size of the second flexible circuit board 1200.

[0180] Furthermore, the area in which the first circuit pattern 210 and the second circuit pattern 220 are arranged may increase. Therefore, the line width or spacing of the first circuit pattern 210 and the second circuit pattern 220 can be controlled. This makes it possible to prevent short circuits between the first circuit pattern 210 and the second circuit pattern 220.

[0181] Therefore, the reliability of the second flexible circuit board is improved.

[0182] Furthermore, the first flexible circuit board alone can supply power to the display panel and the circuit board. This eliminates the need to drive the first flexible circuit board and the second flexible circuit board individually.

[0183] Furthermore, the second flexible circuit board does not include a third circuit pattern with a larger width. Therefore, when forming the circuit pattern on the second flexible circuit board, the difference in line width can be reduced by the difference in line width.

[0184] Referring to Figures 19 and 20, the second flexible circuit board 1200 may have a third region 3A and a fourth region 4A defined.

[0185] The third region 3A is adjacent to the second pad portion 212b. The fourth region 4A is adjacent to the fourth pad portion 222b.

[0186] The second flexible circuit board 1200 can be bent in at least one of the third region 3A and the fourth region 4A. More specifically, one region of the third region 3A can be bent. That is, the third region 3A can include a bending region.

[0187] As a result, stress may be generated in the third region 3A. Also, one region of the first wiring section 221 may overlap with the bending region.

[0188] Therefore, if the thickness of one region of the first wiring section 221 that overlaps with the bending region is thick, the bending characteristics may deteriorate.

[0189] Furthermore, a crack may form in a region of the first wiring section 221 that overlaps with the bending region due to the stress.

[0190] As a result, the layer structure of one region of the first wiring section that overlaps with the bending region may differ from the layer structure of other regions.

[0191] For example, the layer structure of one region of the first wiring section that overlaps with the bending region may be the same as or similar to the layer structure of one region of the wiring pattern as shown in Figures 7 to 18 above.

[0192] This prevents cracks from occurring in the bonding layer due to stress when bending the second flexible circuit board.

[0193] The flexible circuit board module according to the embodiment includes a first flexible circuit board and a second flexible circuit board.

[0194] The first flexible circuit board includes a power supply pattern. The power supply pattern can stably supply power to the display panel.

[0195] The aforementioned power supply pattern is connected to multiple pad patterns. This improves the power supply efficiency of the power supply pattern.

[0196] Furthermore, the first flexible circuit board includes a test pattern. This test pattern allows the current flow of the first flexible circuit board to be verified before use. This improves the reliability of the electronic device.

[0197] Furthermore, the first flexible circuit board includes a first region and a second region. The first region is bendable. The layer structure of the wiring pattern overlapping the first region may differ from the layer structure of the other regions. This improves the bending reliability of the first flexible circuit board.

[0198] The second flexible circuit board may omit the power supply pattern. This may reduce the size of the second flexible circuit board. In addition, the uniformity of the patterns placed on the second flexible circuit board will be improved.

[0199] Because the flexible circuit board module is flexible, it can be used in a variety of electronic devices.

[0200] For example, referring to Figure 21, the flexible circuit board module can be applied to a curved, flexible touch device. Therefore, the user can bend or fold the touch device by hand.

[0201] Referring to Figure 22, the flexible circuit board module can be applied to a wearable touch device including a curved display.

[0202] Referring to Figure 23, the flexible circuit board module can be applied to a variety of electronic devices having a display portion, such as TVs, monitors, and notebooks. The flexible circuit board module can also be used in electronic devices having a curved display portion.

[0203] The features, structures, and effects described in the above-described embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, and effects exemplified in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary skill in the art to which the embodiment belongs. Therefore, content related to such combinations and modifications should be interpreted as being within the scope of the present invention.

[0204] Furthermore, although the above description has focused on embodiments, these are merely illustrative examples and do not limit the present invention. Anyone with ordinary skill in the art to which the present invention belongs will understand that a variety of modifications and applications not exemplified above are possible, without departing from the essential characteristics of these embodiments. For example, each component specifically shown in the embodiments can be modified and implemented. Any differences related to such modifications and applications should be interpreted as falling within the scope of the present invention as defined in the appended claims.

Claims

1. Including a first flexible circuit board and a second flexible circuit board, The first flexible circuit board is, A substrate, a power supply pattern and a test pattern placed on the substrate, The power supply pattern and the test pattern include a protective layer disposed on the power supply pattern, The power supply pattern includes a first wiring pattern, a first-first pad pattern, and a first-second pad pattern. The first pad pattern is connected to the display panel, The first and second pad patterns are connected to the circuit board. A flexible circuit board module in which the first width of the first wiring pattern is 1 mm to 3 mm.

2. The flexible circuit board module according to claim 1, wherein the first wiring pattern is connected to a plurality of first-1 pad patterns and a plurality of first-2 pad patterns.

3. The first pad pattern has a second-first width and a second-second width, The width of the second-first section is 15 μm to 25 μm. The flexible circuit board module according to claim 1, wherein the width of the second-second section is 3 μm to 14 μm.

4. The flexible circuit board module according to claim 1, wherein the third width of the first- and second pad patterns is 100 μm to 180 μm.

5. The test pattern includes a second wiring pattern, a second-first pad pattern, and a second-second pad pattern. The aforementioned test pattern includes a first test pattern, a second test pattern, and a third test pattern. The first test pattern and the second test pattern include the second wiring pattern, the 2-1 pad pattern, and the 2-2 pad pattern, The flexible circuit board module according to claim 1, wherein the third test pattern includes the second wiring pattern and the 2-1 pad pattern.

6. The first flexible circuit board has a first region defined, The first region is defined as the region in which the first wiring pattern extends in a linear direction. The first region is adjacent to the first-1 pad pattern, A flexible circuit board module according to claim 1, wherein one region of the first region is bent.

7. The first wiring pattern includes a first bonding layer, The first-1 pad pattern and the first-2 pad pattern include the first bonding layer and the second bonding layer, The first bonding layer and the second bonding layer contain tin, The flexible circuit board module according to claim 6, wherein the thickness of the first bonding layer is smaller than the thickness of the second bonding layer.

8. The first wiring pattern includes a metal layer and a bonding layer on the metal layer, The bonding layer is arranged in a portion of the metal layer, An open region is formed on the metal layer by the first bonding layer. The flexible circuit board module according to claim 6, wherein the protective layer is disposed inside the open region.

9. The flexible circuit board module according to claim 8, wherein the protective layer includes a first protective layer disposed inside the open region and a second protective layer on the first protective layer.

10. The second flexible circuit board is, Substrate and A circuit pattern arranged on the substrate, Includes a protective layer disposed on the circuit pattern, The flexible circuit board module according to claim 1, wherein the circuit pattern includes a first circuit pattern connected to the chip and the display panel, and a second circuit pattern connected to the chip and the circuit board.

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