KR20180010890A - Flexible circuit board, cof module and electronic device comprising the same - Google Patents

Abstract

A flexible circuit board according to an embodiment comprises: a substrate which includes a bending area; a first wiring pattern layer which is disposed on one surface of the substrate; a first plating layer which is disposed in an area other than the bending area on the first wiring pattern layer; a first protective layer which covers a part of the upper surface of the first plating layer and the the upper surface of the first wiring pattern layer on the bending area, and is disposed wider than the bending area; and a second plating layer which is disposed on the first plating layer, and is disposed in an area other than the area where the first protective layer is disposed. The first protective layer includes: a second wiring pattern layer which is disposed higher than the upper surface of the second plating layer and disposed on the other surface opposite to the surface of the substrate; a third plating layer which is disposed on the second wiring pattern layer; a fourth plating layer which is disposed on the third plating layer; and a second protective layer which is disposed on the fourth plating layer, and is disposed on the bending area.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible circuit board, a COF module, and an electronic device including the flexible circuit board. 2. Description of the Related Art Flexible circuit boards, COF modules,

Embodiments relate to a flexible circuit board, a COF module and an electronic device including the same. In detail, the flexible circuit board can be a flexible printed circuit board for COF which can be used in various electronic devices.

Recently, a variety of electronic products are becoming thinner, smaller, and lighter. Accordingly, various studies for mounting a semiconductor chip at a high density in a narrow region of an electronic device have been carried out.

Among them, since a COF (Chip On Film) method uses a flexible substrate, it can be applied to both a flat panel display and a flexible display. That is, the COF method is attracting attention because it can be applied to various wearable electronic devices. In addition, since the COF method can realize a fine pitch, it can be used to realize a high resolution display as the number of pixels increases.

COF (Chip On Film) is a method of mounting a semiconductor chip on a flexible circuit board in the form of a thin film. For example, the semiconductor chip may be an integrated circuit (IC) chip or a large scale integrated circuit (LSI) chip.

However, the COF flexible circuit board has problems such as repeated bending of a circuit pattern formed on a flexible substrate, cracking in the process of bonding in a bent state, or breakage due to tensile force generated at bending There is a problem that can occur.

The embodiments are intended to provide a flexible circuit board, a COF module and an electronic device including the same which have improved reliability.

A flexible circuit board according to an embodiment includes: a substrate including a bending region; A wiring pattern layer disposed on one surface of the substrate; A first plating layer disposed on a region other than the bending region on the wiring pattern layer; A protective layer covering the upper surface of the wiring pattern layer on the bending area and a part of the upper surface of the first plating layer and being wider than the bending area; And a second plating layer disposed on the first plating layer and disposed in a region other than the region where the protective layer is disposed, wherein the protective layer is disposed higher than the upper surface of the second plating layer.

A flexible circuit board according to an embodiment includes a substrate including a bending region; A first wiring pattern layer disposed on one surface of the substrate; A first plating layer disposed on a region other than the bending region on the first wiring pattern layer; A first passivation layer covering a portion of the upper surface of the first wiring pattern layer and the upper surface of the first plating layer on the bending region and being wider than the bending region; And a second plating layer disposed on the first plating layer and disposed in a region other than a region where the first protective layer is disposed, wherein the first protective layer is disposed higher than the upper surface of the second plating layer, A second wiring pattern layer disposed on the other surface opposite to the one surface of the substrate; A third plating layer disposed on the second wiring pattern layer; A fourth plating layer disposed on the third plating layer; And a second protective layer disposed on the fourth plating layer and disposed on the bending area.

An electronic device according to an embodiment includes a flexible circuit board, the flexible circuit board including: a substrate including a bending area; A wiring pattern layer disposed on one surface of the substrate; A first plating layer disposed on a region other than the bending region on the wiring pattern layer; A protective layer covering the upper surface of the wiring pattern layer on the bending area and a part of the upper surface of the first plating layer and being wider than the bending area; And a second plating layer disposed on the first plating layer and disposed in a region other than a region where the protective layer is disposed, wherein the protective layer is disposed higher than the upper surface of the second plating layer, A display panel connected to the display panel; And a printed circuit board connected to the other end opposite to the one end of the flexible circuit board.

A method of manufacturing a flexible circuit board according to an embodiment of the present invention includes: preparing a substrate having a thickness of 12 to 125 탆; Forming a wiring pattern layer having a thickness of 1 占 퐉 to 20 占 퐉 on one surface of the substrate; Forming a first plating layer having a thickness of 0.1 占 퐉 or less on a region other than a bending region on the wiring pattern layer; Disposing a protective layer having a thickness of 1 mu m to 20 mu m so as to cover the wiring pattern layer on the bending area and a part of the first plating layer; And disposing a second plating layer having a thickness of 1 占 퐉 or less on a region other than the region where the protective layer is disposed on the first plating layer.

The flexible circuit board according to the embodiment may have a wiring pattern layer disposed on a substrate including a bending region and a first plating layer disposed on an area other than the bending region on the wiring pattern layer. Accordingly, the protective layer covers the upper surface of the wiring pattern layer on the bending area and a part of the upper surface of the first plating layer, and can be arranged wider than the bending area.

That is, according to the embodiment, as the one surface of the protection layer comes into contact with the first plating layer, cracks are formed on the wiring pattern layer and / or the plating layer at a portion stretched when the flexible circuit board and the chip on film (COF) Can be prevented. Accordingly, the reliability of the flexible circuit board and the COF module including the flexible circuit board according to the embodiment can be improved.

In addition, in the embodiment, the plating layer is partially disposed on the wiring baton layer to reduce the generation of metal particles, for example, Sn particles generated in the plating process, Reliability can be improved.

In addition, in the embodiment, as the protective layer of at least one of the first protective layer and the second protective layer of the double-sided COF flexible circuit board contacts the wiring pattern layer, cracks due to a change in tensile force at the time of bending are prevented, The semiconductor chip can be mounted in a narrow area of the device at a high density and a high resolution display can be realized.

1 to 4 are various sectional views of a flexible circuit board according to an embodiment.
5 to 7 are various cross-sectional views of a double-sided flexible circuit board according to an embodiment.
8 to 11 are cross-sectional views illustrating a manufacturing process of a double-sided flexible circuit board according to an embodiment of the present invention.
12 is a cross-sectional view showing a connection relationship of a COF module including a flexible circuit board according to an embodiment.
13 to 15 are views relating to an electronic device including a flexible circuit board according to an embodiment.

In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under / under" Quot; includes all that is formed directly or through another layer. The criteria for top / bottom or bottom / bottom of each layer are described with reference to the drawings.

Also, when a part is referred to as being "connected" to another part, it includes not only a case of being "directly connected" but also a case of being "indirectly connected" with another member in between. Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

The thickness or the size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 7, a flexible circuit board according to an embodiment includes a substrate 100; A wiring pattern layer (200) disposed on the substrate (100); A plating layer 300 and a protective layer 400. [

The substrate 100 includes the wiring pattern layer 200; And may be a supporting substrate for supporting the plating layer 300 and the protective layer 400.

The substrate 100 may include a bending region BA and a region other than the bending region NBA. That is, the substrate 100 may include a bending area BA where bending is performed and a non-bending area NBA other than the bending area.

The substrate 100 may be a flexible substrate. That is, the substrate 100 may include a soft plastic. For example, the substrate 100 may be a polyimide (PI) substrate. However, the present invention is not limited thereto, and the substrate may be a substrate made of a polymer material such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). Accordingly, the flexible circuit board including the substrate 100 can be used in various electronic devices having a curved display device. For example, since the flexible circuit board including the substrate 100 has excellent flexibility characteristics, it may be suitable for mounting a semiconductor chip of a wearable electronic device.

The substrate 100 may be an insulating substrate. That is, the substrate 100 may be an insulating substrate supporting various wiring patterns.

The substrate 100 may have a thickness of 12 to 125 탆. For example, the substrate 100 may have a thickness of 50 탆 or less. For example, the substrate 100 may have a thickness of 20 [mu] m to 40 [mu] m. If the thickness of the substrate 100 is more than 125 μm, the overall thickness of the flexible circuit board may increase.

Wiring may be disposed on the substrate 100. The wiring may be a plurality of patterned wirings. For example, the plurality of wirings on the substrate 100 may be disposed apart from each other. That is, the wiring pattern layer 200 may be disposed on one side of the substrate 100.

The area of the substrate 100 may be larger than the area of the wiring pattern layer 200. In detail, the planar area of the substrate 100 may be larger than the planar area of the wiring pattern layer 200. That is, the wiring pattern layer 200 may be partially disposed on the substrate 100. For example, the bottom surface of the wiring pattern layer 200 may be in contact with the substrate 100, and the substrate 100 may be exposed between the plurality of wiring patterns. ≪ / RTI > For example, the wiring pattern layer 200 may include a metal material having excellent electrical conductivity. More specifically, the wiring pattern layer 200 may include copper (Cu). However, the embodiment is not limited thereto, and copper, aluminum, chromium, nickel, silver and molybdenum may be used. And may include at least one of gold (Au), titanium (Ti), and alloys thereof.

The wiring pattern layer 200 may be arranged to have a thickness of 1 to 20 탆. For example, the wiring pattern layer 200 may be arranged to have a thickness of 5 to 20 탆. For example, the wiring pattern layer 200 may be arranged to have a thickness of 5 to 15 탆.

If the thickness of the wiring pattern layer 200 is less than 1 mu m, the resistance of the wiring pattern layer may increase. When the thickness of the wiring pattern layer 200 is more than 20 탆, it may be difficult to realize a fine pattern.

A plating layer 300 may be disposed on the wiring pattern layer 200. The plating layer 300 may include a first plating layer 310 and a second plating layer 320.

The first plating layer 310 may be partially disposed on the wiring pattern layer 200. The first plating layer 310 may be disposed on a region (NBA) other than the bending region on the wiring pattern layer 200.

That is, the first plating layer 310 may not be disposed on the bending area BA on the wiring pattern layer 200. Accordingly, the first plating layer 310 may include the first open portion OA1 in the bending region BA. For example, the width of the first open portion OA1 may correspond to the width of the bending region BA. In detail, the side surface of the first plating layer 310 may be disposed in the bending region BA and the boundary region of the region NBA other than the bending region.

The first plating layers 310 may be spaced apart from each other by the first openings. For example, the first plating layer 311 outside the one end of the bending region may not be connected to the first plating layer 312 outside the other end of the bending region.

The second plating layer 320 may be disposed on the first plating layer 310. The second plating layer 320 may be partially disposed on the first plating layer 310. The second plating layer 320 may be disposed in a region other than a region where the protective layer 400 is disposed on the first plating layer 310. That is, the second plating layer 320 may be disposed in a region other than the region where the protective layer 400 is disposed on the first plating layer 310.

The second plating layer 320 may be disposed on a region (NBA) other than the bending region of the first plating layer 310. That is, the second plating layer 320 may not be disposed on the bending area BA. Accordingly, the second plating layer 320 may include a second open portion OA2. For example, the width of the second open portion OA2 may be greater than the width of the bending region BA. In detail, the side surface of the second plating layer 320 may be spaced apart from the bending region BA and the boundary region of the region NBA other than the bending region.

The second plating layer 320 may be spaced apart from each other by the second openings. For example, the second plating layer 321 outside the one end of the bending region may not be connected to the second plating layer 322 outside the other end of the bending region.

The width of the first open portion OA1 may be different from the width of the second open portion OA2. The width of the first open portion OA1 may be smaller than the width of the second open portion OA2.

The area of the second plating layer 320 may be smaller than the area of the first plating layer 310. In detail, the second plating layer 320 may be smaller in planar area than the first plating layer 310.

A protective layer 400 may be disposed on the first open portion OA1 and the second open portion OA2.

The width W1 of the protective layer 400 disposed in the first open portion OA1 may be smaller than the width W2 of the protective layer 400 disposed in the second open portion OA2.

The plating layer 300 may include tin (Sn). For example, the first plating layer 310 and the second plating layer 320 may include tin (Sn).

For example, the wiring pattern layer 200 may be formed of copper (Cu), and the first plating layer 310 and the second plating layer 320 may be formed of tin (Sn). That is, although the first plating layer 310 and the second plating layer 320 are formed of the same tin Sn, in order to realize the structure of the protective layer disposed in the first and second openings, The first plating layer 310 and the second plating layer 320 may be formed by a separate process.

The first plating layer 310 may be coated with tin (Sn), then the protective layer 400 may be applied as an insulating layer, and the second plating layer 320 may be coated with tin (Sn).

For example, when the manufacturing process of the flexible circuit board according to the embodiment includes a heat treatment process such as thermal curing, the copper (Cu) of the wiring pattern layer 200 or the tin (Sn) of the plating layer 300, The diffusion action of the liquid can occur. Accordingly, as the diffusion concentration of copper (Cu) decreases from the first plating layer 310 to the surface of the second plating layer 320, the content of copper (Cu) may be reduced. On the other hand, the content of tin (Sn) may become larger toward the surface of the second plating layer (320) in the first plating layer (310).

That is, the first patterned layer 310 and the second plated layer 320 may be an alloy of tin and copper, due to a chemical action at the lamination interface of the wiring pattern layer 200 and the plating layer 300. The first plating layer 310 and the second plating layer 320 may have different contents of tin and copper. The first plating layer 310 directly contacting the copper wiring pattern layer may have a copper content higher than that of the second plating layer 320. Alternatively, the first plating layer 310 may be an alloy of tin and copper, and the second plating layer 310 may include tin. The plating layer according to the embodiment can prevent electrochemical migration resistance due to the diffusion phenomenon of Cu / Sn, and can prevent short-circuit defects due to metal growth.

However, the present invention is not limited to these examples, and examples thereof include a Ni / Au alloy, Au, electroless nickel immersion gold (ENIG), Ni / Pd alloy, and Organic Solderability Preservative It is of course possible to include any one of them.

The first plating layer 310 may have a thickness different from that of the second plating layer 320. The thickness T1 of the first plating layer 310 may be less than the thickness T2 of the second plating layer 320. [ For example, the first plating layer 310 may have a thickness of 0.1 탆 or less. For example, the second plating layer 320 may have a thickness of 1 μm or less. That is, the total thickness of the plating layer 300 may be 1.1 탆 or less. In detail, the thickness of the first plating layer 310 and the second plating layer 320 may be 1.1 탆 or less.

The protective layer 400 covers the upper surface of the wiring pattern layer 200 on the bending area BA and a part of the first plating layer 310 and may be arranged to be wider than the bending area BA.

The protective layer 400 may be in contact with the wiring pattern layer 200, the first metal layer 310, and the second plating layer 320. The protective layer 400 may be in contact with the upper surface of the wiring pattern layer 200 on the bending region, a part of the upper surface of the first metal layer 310, and the second plating layer 320. The protection layer 400 is formed on the upper surface of the wiring pattern layer 200 of the bending area BA to the first open area OA1 and the upper surface of the wiring pattern layer 200 of the bending area BA to the first open area OA1, The upper surface and side surfaces of the first plating layer 310 and the side surfaces of the second plating layer 320 may be in direct contact with each other. That is, the protective layer 400 according to the embodiment directly contacts the wiring pattern layer 200, the first plating layer 310, and the second plating layer 320 at the same time, The reliability of the flexible circuit board according to the embodiment can be improved. The protective layer 400 may cover one side surface and the upper surface of the first plating layer 310.

That is, the protective layer 400 may overlap the first plating layer 310 in an area (NBA) other than the bending area. The protective layer 400 may not overlap the first plating layer 310 in the bending area BA.

The first overlapping area CA1 in which the first plating layer 310 and the protective layer 400 are in contact with each other at one end of the bending area BA and the second overlapping area CA2 outside the other end of the bending area BA And a second overlap region in which the first plating layer 310 and the protection layer 400 are in contact with each other.

The width of the first overlap region CA1 or the second overlap region CA2 may be 400 占 퐉 or more.

The width of the first overlapping area CA1 or the width of the second overlapping area CA2 may be smaller than the width of the bending area BA. For example, the widths of the first overlapping area CA1 and the second overlapping area CA2 may be smaller than the width of the bending area BA.

The widths of the first overlapping area CA1 and the second overlapping area CA2 may be corresponding or different from each other.

For example, referring to FIG. 3, the width of the first overlap area CA1 may be equal to the width of the second overlap area CA2.

For example, referring to FIG. 4, the width of the first overlap area CA1 may be different from the width of the second overlap area CA2. The width of the first overlapping area CA1 may be smaller than the width of the second overlapping area CA2.

The side surface 410S of the protective layer 400 may have various cross-sectional shapes. The side surface 400S of the protective layer 400 may include an inclined surface or a vertical surface.

For example, referring to FIG. 1, a side surface 400S of the passivation layer 400 may include a sloped surface. Accordingly, the area of contact of the protective layer 400 with the second plating layer 320 can be widened, thereby preventing the protective layer 400 from being stripped.

The side surface 400S of the protective layer 400 may include a curved inclined surface. For example, the side surface 400S of the protective layer 400 may increase as the inclination angle with respect to the first plating layer 310 becomes closer to the first plating layer 310. [ In detail, the side surface 400S of the protective layer 400 may have an acute angle with respect to the first plating layer 310.

For example, referring to FIG. 2, the side surface 400S of the protective layer 400 may include an inclined surface. The side surface 400S of the protective layer 400 may include a straight inclined surface. For example, the side surface 410S of the protective layer 410 may be constant irrespective of the distance from the first plating layer 310 to the first plating layer 310. In detail, the side surface 400S of the protective layer 400 may have an acute angle with respect to the first plating layer 310.

For example, referring to FIGS. 3 and 4, the side surface 400S of the protective layer 400 may include a vertical surface. The side surface 400S of the protective layer 400 may include a straight inclined surface. For example, the side surface 400S of the passivation layer 400 may have an inclination angle of 90 degrees with the first plating layer 310 or the like.

The passivation layer 400 may include an insulating material. The passivation layer 400 may be a resist layer. For example, the protective layer 400 may be a solder resist layer containing an organic polymer material. For example, the protective layer 400 may include an epoxy acrylate resin. In detail, the protective layer 400 may include a resin, a curing agent, a photoinitiator, a pigment, a solvent, a filler, an additive, an acrylic-based monomer, and the like. However, the present invention is not limited thereto, and the protective layer 400 may be a photo-solder resist layer, a cover-lay, or a polymer material.

The thickness T3 of the protective layer 400 may be greater than the thickness T2 of the second plating layer 320. [ Accordingly, the upper surface of the protective layer 400 may be disposed higher than the upper surface of the second plating layer 320. That is, since the upper surface of the protective layer 400 is disposed higher than the upper surface of the second plating layer 320, the protective layer 400 and the second plating layer 320 may have a step.

The thickness of the protective layer 400 in the bending region may be different from the thickness in the region other than the bending region.

The thickness of the protective layer 400 on the bending area may be greater than the thickness of the first passivation layer 410 on the first overlapping area CA1. The thickness of the protective layer 400 on the bending area may be greater than the thickness of the first passivation layer 410 on the second overlapping area CA2.

The thickness T3 of the protective layer 400 in the bending region may be 1 to 20 占 퐉. For example, the thickness T3 of the passivation layer 400 in the bending region may be 5 to 20 占 퐉.

The protective layer 400 may be integrally formed. Accordingly, it is possible to prevent the protective layer 400 from being de-filmed according to the embodiment, and the reliability of the flexible circuit board can be improved. In addition, when the flexible circuit board according to the embodiment is bent, stress due to tensile stress can be dispersed entirely in the integrated protection layer 400, thereby improving reliability. Further, the efficiency of the process of forming the flexible circuit board according to the embodiment can be improved.

5 to 7, a double-sided flexible circuit board according to an embodiment will be described in detail. The embodiment includes a substrate 100 including a bending region, a first wiring pattern layer 210 disposed on one side of the substrate, a first plating layer (not shown) disposed in a region other than the bending region on the first wiring pattern layer 310), a first protective layer (410) covering the upper surface of the first wiring pattern layer on the bending area and a part of the upper surface of the first plating layer and being wider than the bending area, and a second protective layer And a second plating layer (320) disposed in a region other than a region where the first protective layer is disposed, wherein the first protective layer is disposed higher than the upper surface of the second plating layer, A third plating layer (330) disposed on the second wiring pattern layer, a fourth plating layer (340) disposed on the third plating layer, and a second wiring pattern layer (320) A plating layer disposed on the bending region, Which may include a second protective layer 420.

That is, the wiring pattern layer 200 may be disposed on both sides of the flexible substrate 100. The wiring pattern layer 200 may include a first wiring pattern layer 210 and a second wiring pattern layer 220. The first wiring pattern layer 210 is disposed on one surface of the flexible substrate 100 and the second wiring pattern layer 220 is disposed on a second surface opposite to the one surface of the flexible substrate 100 .

The thickness of the first wiring pattern layer 210 may correspond to the thickness of the second wiring pattern layer 220. The thickness of the first wiring pattern layer 210 and the thickness of the second wiring pattern layer 220 may be 1 to 20 μm, respectively.

A first plating layer 310 may be disposed on the first wiring pattern layer 210. Also, a third plating layer 330 may be disposed on the second wiring pattern layer 220.

At least one of the first plating layer 310 and the third plating layer 330 may include a first open portion OA1.

For example, referring to FIG. 5, one of the first plating layer 310 and the third plating layer 330 may include the first open portion OA1. In detail, the first plating layer 310 may include the first open portion OA1.

For example, referring to FIGS. 6 and 7, the first plating layer 310 and the third plating layer 330 may include the first openings OA1, respectively.

6 and 7, the third plating layer 330 is disposed in a region other than the bending region, and the second passivation layer 420 is formed on the second wiring pattern layer 220 And the fourth plating layer 440 is disposed in a region other than the region where the second protective layer is disposed, and the second protection layer 440 is disposed in a region other than the region where the second protective layer is disposed, Layer may be disposed higher than the upper surface of the fourth plating layer.

A second plating layer 320 may be disposed on the first plating layer 310. A fourth plating layer 340 may be disposed on the third plating layer 330.

At least one of the second plating layer 320 and the fourth plating layer 340 may include a second open portion OA2.

For example, referring to FIG. 5, one of the second plating layer 320 and the fourth plating layer 340 may include the second open portion OA2. In detail, the second plating layer 320 may include the second open portion OA2. The width W1 of the first open portion may be different from the width W2 of the second open portion. The width W1 of the first open portion may be smaller than the width W2 of the second open portion.

For example, referring to FIGS. 6 and 7, the second plating layer 320 and the fourth plating layer 340 may include the second openings OA2, respectively.

The first protective layer 410 may be disposed on the second plating layer 320. Also, a second passivation layer 420 may be disposed on the fourth plating layer 3400.

At least one of the first passivation layer 410 and the second passivation layer 420 may have different widths between the top and bottom surfaces.

For example, referring to FIG. 5, the protective layer of one of the first protective layer 410 and the second protective layer 420 may have a width different from that of the top surface and the bottom surface. In detail, the width W1 of the first passivation layer 410 may be different from the width W2 of the top surface. The width W2 of the first passivation layer 410 may be greater than the width W1 of the bottom surface.

6 and 7, the widths of the upper surface and the lower surface of the first passivation layer 410 may be different from those of the second passivation layer 420, respectively.

Referring to FIG. 6, the width W1 of the first passivation layer 410 may be different from the width W2 of the top surface. The width W2 of the first passivation layer 410 may be greater than the width W1 of the bottom surface. In addition, the width W2 of the second protective layer 420 may be different from the width W3 of the bottom surface. The width W2 of the second passivation layer 420 may be greater than the width W3 of the bottom surface. At this time, the width W1 of the lower surface of the first passivation layer 410 may be different from the width W3 of the lower surface of the second passivation layer 420.

Referring to FIG. 7, the width W1 of the first passivation layer 410 may be different from the width W2 of the top surface. The width W2 of the first passivation layer 410 may be greater than the width W1 of the bottom surface. In addition, the width W1 of the second protective layer 420 may be different from the width W2 of the upper surface. The width W2 of the second passivation layer 420 may be greater than the width W1 of the bottom surface. At this time, the width W1 of the lower surface of the first passivation layer 410 may correspond to the width W1 of the lower surface of the second passivation layer 420.

At least one of the first passivation layer 410 and the second passivation layer 420 may contact the wiring pattern layer.

For example, referring to FIG. 5, one of the first passivation layer 410 and the second passivation layer 420 may be in contact with the wiring pattern layer. In detail, the first passivation layer 410 may contact the wiring pattern layer. At this time, the first passivation layer 410 may be tensile and the second passivation layer 420 may be bent in a direction to receive compressive force. As the first protective layer 410 is in contact with the wiring pattern layer, the first pattern layer 201 and the plating layer 300 are cracked at a portion of the flexible circuit board that is stretched when the flexible circuit board is folded. Can be prevented. Therefore, the reliability of the flexible circuit board according to the embodiment can be improved.

6 and 7, the first passivation layer 410 is in contact with the first wiring pattern layer 210, and the second passivation layer 420 is in contact with the second wiring pattern layer 210. For example, (Not shown). At this time, the first protective layer 410 or the second protective layer 420 may be bent in a direction to receive tensile force. Accordingly, when one surface of the first protective layer 410 or one surface of the second protective layer 420 is in contact with the wiring pattern layer, the portion of the first or the second protective layer 420, It is possible to prevent cracks from being generated in the two wiring pattern layers 210 and 220 and / or the plating layers 310, 320, 330, and 340. Therefore, the reliability of the flexible circuit board according to the embodiment can be improved.

The thickness of the first passivation layer 410 may correspond to or different from the thickness of the second passivation layer 420. The thickness of the protective layer may be measured in the bending region.

For example, referring to FIG. 5, the thickness T3 of the first passivation layer 410 may be different from the thickness T4 of the second passivation layer 420. Referring to FIG. The thickness T3 of the first passivation layer 410 may be greater than the thickness T4 of the second passivation layer 420. [ The thickness of the first passivation layer 410 may be 10 to 20 占 퐉 and the thickness of the second passivation layer 420 may be 5 to 15 占 퐉. At this time, the first passivation layer 410 may be tensile and the second passivation layer 420 may be bent in a direction to receive compressive force. That is, since the first protective layer 410 receiving the tensile force has a greater thickness than the second protective layer 420 receiving the compressive force, the portion of the first wiring pattern layer 210 and / or the plating layers 310, 320 can be prevented from being cracked. Therefore, the reliability of the flexible circuit board according to the embodiment can be improved.

6 and 7, the thickness T3 of the first passivation layer 410 may correspond to the thickness T3 of the second passivation layer 420. For example, as shown in FIG. The thickness of the first passivation layer 410 may be 1 to 20 μm and the thickness of the second passivation layer 420 may be 1 to 20 μm.

The first passivation layer 410 and the second passivation layer 420 are in contact with the first and second wiring pattern layers 210 and 220, And the thickness of the second passivation layer 420 may be 5 to 15 占 퐉. At this time, the first passivation layer 410 may be tensile and the second passivation layer 420 may be bent in a direction to receive compressive force. That is, since the first protective layer 410 receiving the tensile force has a greater thickness than the second protective layer 420 receiving the compressive force, the portion of the first wiring pattern layer 210 and / or the plating layers 310, 320 can be prevented from being cracked. Therefore, the reliability of the flexible circuit board according to the embodiment can be improved.

5 to 7, a first overlapping region in which the first plating layer and the one protection layer are in contact with each other at an outer side of one end of the bending region, and a second overlapping region in which the first plating layer and the first And a second overlap region in which the protective layer is in contact.

The width of the first overlap region may correspond to the width of the second overlap region or may be different from each other. A third overlap region in which the third plating layer and the second protection layer are in contact with each other at an outer side of one end of the bending region, And a fourth overlap region in which the third plating layer and the second protective layer are in contact with each other at an outer side of the other end of the bending region.

Referring to FIG. 6, the width of the first overlapping area CA1 may correspond to the width of the second overlapping area CA2. The width of the third overlapping area CA3 may correspond to the width of the fourth overlapping area CA4.

The width of the first overlapping area CA1 may be smaller than the width of the third overlapping area CA3. The width of the second overlapping area CA2 may be smaller than the width of the fourth overlapping area CA4.

Referring to FIG. 7, the width of the first overlapping area CA1 may correspond to the width of the second overlapping area CA2. The width of the first overlapping area CA1 may correspond to the width of the third overlapping area CA3. The width of the second overlapping area CA2 may correspond to the width of the fourth overlapping area CA4.

7, the width W1 of the contact area between the first passivation layer 410 and the first wiring pattern layer 210 is greater than the width W1 of the second passivation layer 420 and the second wiring pattern layer 220 The width W1 of the contact area of the contact area W1. At this time, the thickness of the first protective layer 410 and the thickness of the second protective layer 420 may be the same. That is, the first protective layer and the second protective layer may have corresponding shapes and thicknesses. Stress due to deformation of the substrate on one side and the other side can be minimized. In addition, by improving the contact area between the first and second protective layers and the wiring pattern layer and the plating layer, it is possible to prevent the protective layer from being removed. In addition, since the first and second protective layers have corresponding shapes, the process efficiency can be improved.

That is, in the double-sided flexible circuit board according to the embodiment, the protective layer on the side receiving the tensile force can contact the wiring pattern layer, thereby preventing cracks and breakage of the wiring pattern layer and / or the plating layer due to bending, .

The double-sided flexible circuit board according to the embodiment may include a first protective layer 410 disposed between the first plating layer 310 and the second plating layer 320. That is, the double-sided flexible circuit board according to the embodiment may include the structure of the first protective layer 410, which is partially embedded between the first plating layer 310 and the second plating layer 320, It is possible to prevent the cracks between the wiring patin layer and the plating layer.

In addition, in the double-sided FPCB according to the embodiment, as the protective layer of at least one of the first protective layer and the second protective layer contacts the wiring pattern layer, cracks due to a change in tensile force during bending are prevented, The semiconductor chip can be mounted in a narrow area of the device at a high density and a high resolution display can be realized. In addition, the embodiment can prevent the problems of poor appearance and reliability due to the generation of Sn particles.

Hereinafter, a method of manufacturing the double-sided flexible circuit board according to the embodiment will be described with reference to Figs. 8 to 11. Fig.

A method of manufacturing a flexible circuit board according to an embodiment of the present invention includes: preparing a substrate having a thickness of 12 μm to 125 μm; Forming a wiring pattern layer having a thickness of 1 占 퐉 to 20 占 퐉 on one surface of the substrate; Forming a first plating layer having a thickness of 0.1 占 퐉 or less on a region other than a bending region on the first wiring pattern layer; Disposing a protective layer having a thickness of 1 mu m to 20 mu m so as to cover the first wiring pattern layer on the bending area and a part of the first plating layer; And disposing a second plating layer having a thickness of 1 占 퐉 or less on an area other than the area where the protective layer is disposed on the first plating layer.

In detail, the step of forming the first plating layer in a region other than the bending region on the wiring pattern layer includes: a step of arranging a masking layer in the bending region on the wiring pattern layer; Plating the first plating layer on an area other than the bending area; And removing the masking layer.

Referring to Fig. 8, a double-sided flexible circuit board manufactured according to a dry film masking method or a photo solder resist (PSR) printing method will be described.

First, a first wiring pattern layer 210 and a second wiring pattern layer 220 are prepared on both surfaces of a substrate 100. That is, a circuit is formed on both surfaces of the substrate 100. At this time, the substrate 100 may be a polyimide flexible substrate, and the wiring pattern may include copper.

Next, a dry film may be laminated on the first wiring pattern layer 210 or an upper sacrificial layer T1 may be formed by printing a photo-solder resist layer. The lower sacrificial layer B1 may be formed by laminating a dry film on the second wiring pattern layer 220 or by printing a photo-solder resist layer.

Next, a mask may be disposed on the upper sacrificial layer (T1) and the lower sacrificial layer (B1), and an exposure step for exposing ultraviolet rays may be performed.

Next, a development step of removing the unexposed upper sacrificial layer (T1) and the lower sacrificial layer (B1) may be performed. Thus, the patterned upper sacrificial layer P1 and the patterned lower sacrificial layer P2 can be formed.

Next, a first plating layer 310 may be formed on the peripheral region of the patterned upper sacrificial layer P1. Also, a third plating layer 330 may be formed in the peripheral region of the patterned lower sacrificial layer P2.

Next, the patterned upper sacrificial layer (P1) and the patterned lower sacrificial layer (P2) can be peeled off. Accordingly, the first plating layer 310 and the third plating layer 330 including the first open portion can be formed. At this time, the first plating layer 310 and the third plating layer 330 may each be tin-plated.

Next, first and second protective layers 410 and 420 covering the side surfaces and a part of the upper surface of the first plating layer 310 and the third plating layer 330 may be disposed while filling the first open portion have. The top surfaces of the first and second protective layers 410 and 420 may have a width larger than the bending area.

Next, second and fourth plating layers 320 and 340 may be formed in the peripheral region of the first and second protective layers 410 and 420. That is, the second and fourth plating layers 320 and 340 may be formed to have a lower thickness than the protective layer in a region where the first and second protective layers 410 and 420 are not disposed. Accordingly, the side surfaces of the first and second protective layers 410 and 420 may be in contact with the second and fourth plating layers 320 and 340. At this time, the second plating layer 320 and the fourth plating layer 340 may each be tin-plated.

The double-sided flexible circuit board manufactured according to the PET masking method will be described with reference to Fig.

First, a first wiring pattern layer 210 and a second wiring pattern layer 220 are prepared on both surfaces of a flexible substrate 100. That is, a circuit is formed on both surfaces of the flexible substrate 100. At this time, the flexible substrate 100 may be a polyimide substrate, and the wiring pattern may include copper.

Next, a PET masking film is punched to prepare a PET masking film having a through-hole.

Next, a patterned upper sacrificial layer (P1) may be formed by laminating a PET masking film having through holes on the first wiring pattern layer (210). In addition, a patterned lower sacrificial layer (P2) may be formed by laminating a PET masking film having through holes on the second wiring pattern layer (220).

Next, a first plating layer 310 may be formed in the through hole of the patterned upper sacrificial layer P1. Also, a third plating layer 330 may be formed in the through hole of the patterned lower sacrificial layer P2.

Next, the patterned upper sacrificial layer (P1) and the patterned lower sacrificial layer (P2) can be peeled off. Accordingly, the first plating layer 310 and the third plating layer 330 including the first open portion can be formed. At this time, the first plating layer 310 and the third plating layer 330 may each be tin-plated.

Next, protective layers 410 and 420 covering the side surfaces and a part of the upper surface of the first and third plating layers 310 and 330 may be disposed while filling the first open portion. The upper surfaces of the protective layers 410 and 420 may have a width larger than the bending area.

Next, second and fourth plating layers 320 and 340 may be formed in the peripheral region of the first and second protective layers 410 and 420. That is, the second and fourth plating layers 320 and 340 may be formed to have a lower thickness than the protective layer in a region where the protective layers 410 and 420 are not disposed. Accordingly, the side surfaces of the first and second protective layers 410 and 420 may be in contact with the second and fourth plating layers 320 and 340. At this time, the second plating layer 320 and the fourth plating layer 340 may each be tin-plated.

Referring to Fig. 10, a double-sided flexible circuit board manufactured according to photoresist (PR) printing or gravure printing method will be described.

First, a first wiring pattern layer 210 and a second wiring pattern layer 220 are prepared on both surfaces of a flexible substrate 100. That is, a circuit is formed on both surfaces of the flexible substrate 100. At this time, the flexible substrate 100 may be a polyimide substrate, and the wiring pattern may include copper.

Next, a photoresist ink may be applied on the first wiring pattern layer 210 to form a patterned upper sacrificial layer P1. In addition, a photoresist ink may be printed on the second wiring pattern layer 220 to form a patterned lower sacrificial layer P2.

Next, a first plating layer 310 may be formed on the peripheral region of the patterned upper sacrificial layer P1. Also, a third plating layer 330 may be formed in the peripheral region of the patterned lower sacrificial layer P2.

Next, the patterned upper sacrificial layer (P1) and the patterned lower sacrificial layer (P2) can be peeled off. Accordingly, the first plating layer 310 and the third plating layer 330 including the first open portion can be formed. At this time, the first plating layer 310 and the third plating layer 330 may each be tin-plated.

Next, first and second protective layers 410 and 420 covering the side surfaces and a part of the upper surface of the first and third plating layers 310 and 330 may be disposed while filling the first open portion. The upper surface of the protective layer may have a width larger than the bending area.

Next, second and fourth plating layers 320 and 340 may be formed around the first and second protective layers. That is, the second and fourth plating layers 320 and 340 may be formed to have a lower thickness than the protective layer in a region where the first and second protective layers are not disposed. Accordingly, the side surfaces of the protective layer may contact the second and fourth plating layers 320 and 340. At this time, the second plating layer 320 and the fourth plating layer 340 may each be tin-plated.

Referring to Fig. 11, a double-sided flexible circuit board manufactured according to the Spurt Jar plating method will be described.

First, a first wiring pattern layer 210 and a second wiring pattern layer 220 are prepared on both surfaces of a flexible substrate 100. That is, a circuit is formed on both surfaces of the flexible substrate 100. At this time, the flexible substrate 100 may be a polyimide substrate, and the wiring pattern may include copper.

Next, the first plating layer 310 and the third plating layer 330 including the first open portion may be formed in the region corresponding to the bending region by plating the Spurt Jar. At this time, the first plating layer 310 and the third plating layer 330 may each be tin-plated.

Next, a protective layer covering the side surfaces and a part of the upper surface of the first and third plating layers 310 and 330 may be disposed while filling the first open portion. The upper surface of the protective layer may have a width larger than the bending area.

Next, second and fourth plating layers 320 and 340 may be formed in the peripheral region of the first and second protective layers 410 and 420. That is, the second and fourth plating layers 320 and 340 may be formed to have a lower thickness than the protective layer in the region where the first and second protective layers 410 and 420 are not disposed. Accordingly, the side surfaces of the protective layer may contact the second and fourth plating layers 320 and 340. At this time, the second plating layer 320 and the fourth plating layer 340 may each be tin-plated.

Next, a COF module including a flexible circuit board according to an embodiment will be described. A COF module in which a driving chip is mounted can be manufactured by disposing a driving chip on the wiring pattern layer 200 that can be electrically connected to the wiring pattern layer 200 on the flexible circuit substrate according to the embodiment .

Referring to FIG. 12, a flexible circuit board according to an embodiment includes a flexible substrate 100 including the bending region and the non-bending region described above; A wiring pattern layer (200) disposed on the flexible substrate; A first plating layer (310) disposed on a non-bending region on the wiring pattern layer; A protective layer (400) covering the wiring pattern layer on the bending area and a part of the first plating layer and being disposed wider than the bending area; And a second plating layer (320) disposed in a peripheral region of the protective layer on the first plating layer, wherein the protective layer is disposed to a thickness greater than that of the second plating layer, , The upper surface of the first plating layer and the second plating layer.

The chip on film (COF) module 10 according to the embodiment may include a driving chip 40 disposed on the non-bending region of the flexible circuit board.

For example, in the bending area BA, the soft substrate 100 may have a shape similar to a C shape. In detail, in the bending area BA, the cross section of the flexible substrate 100 may have a curved shape. The bending area BA may be a part where one side of the substrate is bent and facing one side or an area where the other side of the substrate faces the other side.

For example, in the non-bending region NBA, the flexible substrate 100 may have a shape similar to a plate shape. In detail, the cross section of the soft substrate 100 in the non-bending area NBA may have a straight line shape. The non-bending region may include an area where the substrate is partially bent to connect with a display panel or a separate circuit board. That is, the non-bending region may be a region where one surface of the substrate is not facing one surface.

The bending area BA may be disposed between the non-bending areas NBA. That is, the bending area BA may be a part that is bent to connect the flexible circuit board to the display panel and the printed circuit board. The cross-sectional area of the bending area BA may be smaller than the cross-sectional area of the non-bending area NBA. Accordingly, the flexible circuit board may be disposed between the display panel and the printed circuit board.

The COF module 10 is positioned between the display panel 20 and the printed circuit board 30 to connect an electrical signal. At this time, the printed circuit board 30 may be a rigid printed circuit board or a flexible printed circuit board.

One end of the COF module 10 including the flexible circuit board according to the embodiment is electrically connected to the display panel 20 in contact with the display panel 20 and the other end thereof is in contact with the printed circuit board 30 And thus can be electrically connected. Here, the contact can mean direct contact. Or may be contacted via an anisotropic conductive film (ACF).

For example, the anisotropic conductive film may be disposed between the COF module 10 and the printed circuit board 30. The COF module 10 and the printed circuit board 30 may be bonded together and electrically connected by the anisotropic conductive film. The anisotropic conductive film may be a resin in which conductive particles are dispersed. Therefore, an electrical signal connected by the printed circuit board 30 can be transmitted to the COF module 10 through the conductive particles included in the anisotropic conductive film.

That is, the flexible circuit board 10 may be connected to the display panel 20 by the first bonding area A1. The flexible printed circuit board 10 may be connected to the printed circuit board 30 by a second bonding area A2. The first bonding area A1 and the second bonding area A2 may be unidirectional or non-bendable.

A first bonding area A1 in which the flexible circuit board 10 is connected to the display panel 20 and a second bonding area A2 in which the flexible circuit board 10 is connected to the printed circuit board 30 The bending area BA may be located at the center of the bending area BA.

Since the COF module 10 includes a flexible substrate, the COF module 10 may have a rigid shape or a bending shape between the display panel 20 and the printed circuit board 30.

Since the COF module 10 can be bent and connected between the display panel 20 and the substrate 30 disposed opposite to each other, the thickness of the electronic device can be reduced and the degree of freedom of design can be improved. have. In addition, since the COF module 10 including the flexible substrate may not break the wiring even in a curved shape, the reliability of the electronic device including the COF module can be improved.

Because the COF module is flexible, it can be used in a variety of electronic devices.

For example, referring to FIG. 13, the COF module may be included in a flexible flexible touch window. Accordingly, the touch device device including the same may be a flexible touch device device. Therefore, the user can bend or bend by hand. Such a flexible touch window can be applied to a wearable touch or the like.

Referring to FIG. 14, the COF module may be included in various wearable touch devices including a curved surface display. Therefore, the electronic device including the COF module can be made slimmer or lighter.

Referring to FIG. 15, the COF module may be used in various electronic devices having a display portion such as a TV, a monitor, and a notebook. At this time, the COF module may be used in an electronic device having a curved display portion.

However, the embodiment is not limited thereto, and it is a matter of course that such a COF flexible circuit board and the COF module processed therefrom can be used for various electronic devices.

The features, structures, effects and the like described in the foregoing embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

Claims (13)

A substrate comprising a bending region;
A wiring pattern layer disposed on one surface of the substrate;
A first plating layer disposed on a region other than the bending region on the wiring pattern layer;
A protective layer covering the upper surface of the wiring pattern layer on the bending area and a part of the upper surface of the first plating layer and being wider than the bending area; And
And a second plating layer disposed on the first plating layer and disposed in a region other than a region where the protective layer is disposed,
And the protective layer is disposed higher than the upper surface of the second plating layer. The method according to claim 1,
Wherein the thickness of the protective layer is 1 占 퐉 to 20 占 퐉. The method according to claim 1,
Wherein the protective layer is in direct contact with the upper surface of the wiring pattern layer and the upper surface of the first plating layer. The method of claim 3,
Wherein the protective layer comprises an inclined surface,
Wherein the protective layer is in direct contact with a side surface of the second plating layer. The method of claim 3,
Wherein the protective layer is integrally formed. The method according to claim 1,
And a second overlapping area in which the first plating layer and the protective layer are in contact with each other at a first overlapping area where the first plating layer and the protective layer are in contact with each other and outside the other end of the bending area outside the one end of the bending area, ,
Wherein a thickness of the protective layer on the bending region is larger than a thickness of the protective layer on the first overlap region or the second overlap region. A substrate comprising a bending region;
A first wiring pattern layer disposed on one surface of the substrate;
A first plating layer disposed on a region other than the bending region on the first wiring pattern layer;
A first passivation layer covering a portion of the upper surface of the first wiring pattern layer and the upper surface of the first plating layer on the bending region and being wider than the bending region;
And a second plating layer disposed on the first plating layer and disposed in a region other than a region where the first protective layer is disposed,
Wherein the first protective layer is disposed higher than the upper surface of the second plating layer,
A second wiring pattern layer disposed on the other surface opposite to the one surface of the substrate;
A third plating layer disposed on the second wiring pattern layer;
A fourth plating layer disposed on the third plating layer; And
And a second protective layer disposed on the fourth plating layer and disposed on the bending region. 8. The method of claim 7,
Wherein a width of a contact area between the first protective layer and the first wiring pattern layer is equal to a width of a contact area between the second protective layer and the second wiring pattern layer. 8. The method of claim 7,
Wherein the thickness of the first protective layer and the thickness of the second protective layer are the same. 8. The method of claim 7,
The third plating layer is disposed in an area other than the bending area,
Wherein the second protective layer covers a part of the upper surface of the second wiring pattern layer and the third plating layer on the bending region and is disposed wider than the bending region,
The fourth plating layer is disposed in a region other than the region where the second protective layer is disposed,
And the second protective layer is disposed higher than the upper surface of the fourth plating layer. A flexible circuit board,
The flexible circuit board includes:
A substrate comprising a bending region;
A wiring pattern layer disposed on one surface of the substrate;
A first plating layer disposed on a region other than the bending region on the wiring pattern layer;
A protective layer covering the upper surface of the wiring pattern layer on the bending area and a part of the upper surface of the first plating layer and being wider than the bending area;
And a second plating layer disposed on the first plating layer and disposed in a region other than a region where the protective layer is disposed,
The protective layer is disposed higher than the upper surface of the second plating layer,
A display panel connected to one end of the flexible circuit board; And
And a printed circuit board connected to the other end opposite to the one end of the flexible circuit board. Preparing a substrate having a thickness of 12 탆 to 125 탆;
Forming a wiring pattern layer having a thickness of 1 占 퐉 to 20 占 퐉 on one surface of the substrate;
Forming a first plating layer having a thickness of 0.1 占 퐉 or less on a region other than a bending region on the wiring pattern layer;
Disposing a protective layer having a thickness of 1 mu m to 20 mu m so as to cover the wiring pattern layer on the bending area and a part of the first plating layer;
And disposing a second plating layer having a thickness of 1 占 퐉 or less on a region other than a region where the protective layer is disposed on the first plating layer. 13. The method of claim 12,
Forming a first plating layer in a region other than a bending region on the wiring pattern layer,
Disposing a masking layer on the bending region on the wiring pattern layer;
Plating the first plating layer on an area other than the bending area; And
And removing the masking layer
A method of manufacturing a flexible circuit board.

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