Flexible printed circuit, electronic device including the same, and method of manufacturing flexible printed circuit

Abstract

To provide a flexible printed circuit board with improved product reliability by including a plating layer formed as a thin film in a bending area, an electronic device including the flexible printed circuit board, and a method of manufacturing the same.SOLUTION: A flexible printed circuit board 1 includes a base film 10 including a bending region 100, a first region 101, and a second region 102, and in which the bending region is located between the first region and the second region, a plurality of first wiring patterns 20 formed on one surface of the base film, a first plated layer covering the plurality of first wiring patterns, a first protective layer 30 formed on the bending region of the base film so as to cover the first plating layer, and a second plated layer formed to cover the first plated layer on which the first protective layer is not formed, and the first plating layer on the bending region is formed with a thickness of 0.05 to 0.25 μm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flexible printed circuit board, an electronic device including the same, and a flexible printed circuit board. The present invention relates to a method for manufacturing a substrate. [Background technology]

[0002] Recently, with the miniaturization of electronic devices, chip-on-fill (CFP) using flexible printed circuit boards has become popular. Chip On Film (COF) packaging technology is used. The COF package technology using the printed circuit board is used in, for example, liquid crystal display devices (Li quid Crystal Display (LCD) and Organic Light Emitting Diode (Organic Light Emitting Diode) nic Light Emitting Diode) display devices and other flat It is used in flat panel displays (FPD).

[0003] Flexible printed circuit boards are flexible and do not break or bend when used in electronic devices. When a flexible printed circuit board is used, it is bent. The durability of the flexible printed circuit board may decrease at the damaged areas.

[0004] In particular, after forming a conductive wiring pattern, it is necessary to protect the wiring pattern or to improve the bonding strength with electronic components. To ensure this, a plating layer is formed, but the plating layer is not covered by wiring during or after plating. An alloy layer (IMC layer) formed when materials contained in the pattern and plating layer diffuse into each other. This alloy layer is harder than the wiring pattern, so its flexibility is reduced. This can be a major cause of cracks occurring when the flexible printed circuit board is bent.

[0005] On the other hand, in order to prevent cracks from occurring at the bent parts of the flexible printed circuit board, After the turns are formed, a protective layer is preferably formed to cover the turns, and then a plating layer is formed on the terminals. However, during plating of the terminals, cavities may occur at the boundary between the protective layer and the plating layer due to local cell phenomenon. In order to solve this problem, Korean Patent Publication No. 2000-62154 (hereinafter referred to as "Prior Art 1") is disclosed. However, the prior art 1 is intended to prevent the local battery phenomenon, and is flexible. Since the circuit failure at the bent part of the PCB is not taken into consideration, there is still a risk of circuit failure at the bent part. It contains danger. Summary of the Invention [Problem to be solved by the invention]

[0006] The technical problem to be solved by the present invention is to form a thin plating layer on a bending region. A flexible printed circuit board having improved product reliability by including the same, and an electronic device including the same The present invention aims to provide an apparatus for

[0007] Another technical problem to be solved by the present invention is to provide a method for manufacturing a plated product having a thin film formed in a bending region. The present invention provides a method for manufacturing a flexible printed circuit board that improves product reliability by including a layer. That's what we can do.

[0008] The technical problem of the present invention is not limited to the above-mentioned technical problem, and other technical problems not mentioned above may be solved. The subject matter will become clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0009] In order to achieve the above technical objectives, a flexible printed circuit board according to an embodiment of the present invention is provided. The plate is a base film including a bending region, a first region, and a second region, the bending region being a base film disposed between the first region and the second region; and a first wiring pattern formed on one surface of the first insulating film; and a second wiring pattern covering the first wiring patterns. 1 plating layer, and a base film is formed on the bending region of the base film so as to cover the first plating layer. and a first protective layer formed on the first plating layer on which the first protective layer is not formed. and a second plating layer formed on the bent area, the first plating layer having a thickness of 0.05 to 0. It is formed to a thickness of 25 μm.

[0010] In some embodiments of the present invention, the first wiring pattern includes an element connection portion, The first protective layer does not have to be formed on the element connection portion.

[0011] In some embodiments of the present invention, the second plating layer is formed so as to cover the element connection portion. The second insulating layer 21 may be formed as follows.

[0012] In some embodiments of the present invention, the opposite surface of the base film is A plurality of second wiring patterns formed on the surface, and a third plating layer covering the second wiring patterns. and a second plating layer formed on the bent region of the base film so as to cover the third plating layer. A protective layer is formed to cover the third plating layer where the second protective layer is not formed. A third plating layer may be further included.

[0013] In some embodiments of the present invention, the third plating layer has a thickness of 0.05 to 0.25 μm. It may be further formed.

[0014] In some embodiments of the present invention, the first wiring pattern is formed inside the base film. The semiconductor device may further include a via that electrically connects the first wiring pattern to the second wiring pattern.

[0015] In some embodiments of the present invention, the second plating layer is thicker than the first plating layer. It may be formed.

[0016] In order to achieve the above technical objectives, a flexible printed circuit board according to an embodiment of the present invention is provided. The method for manufacturing the plate includes providing a base film including a bending region, a first region, and a second region. the bending region is disposed between the first region and the second region, and the base film forming a plurality of first wiring patterns on one surface of the substrate so as to cover the plurality of first wiring patterns; A first plating layer is formed on the bent region of the base film so as to cover the first plating layer. A first protective layer is formed to cover the first plating layer on which the first protective layer is not formed. forming a second plating layer, the first plating layer on the bend region having a thickness of 0.05 to 0 It is formed to a thickness of .25μm.

[0017] In some embodiments of the present invention, the opposite surface of the base film is A plurality of second wiring patterns are formed on the surface, and a third wiring pattern is formed to cover the plurality of second wiring patterns. A plating layer is formed on the bent region of the base film so as to cover the third plating layer. A second protective layer is formed to cover the third plating layer on which the second protective layer is not formed. The method may further include forming a fourth plating layer.

[0018] In some embodiments of the present invention, forming the second plating layer comprises The thickness of the plating layer may be greater than that of the plating layer.

[0019] In order to achieve the above technical objective, an electronic device according to an embodiment of the present invention includes a first circuit element, a second circuit element; and a connection surface connected to the first circuit element and a connection surface between the first circuit element and the second circuit element. A first region extending in parallel, connected to a second circuit element, and extending in parallel to a connection surface with the second circuit element A second region that extends from the first region to the second region and connects the first region to the second region at an angle of 90 degrees to 180 degrees. a flexible printed circuit board including a bending region that can be bent by a bending force; The support substrate includes a base film and a plurality of insulating films formed on at least one surface of the base film. a first plating layer formed to cover the wiring patterns; a first protective layer formed in the recessed region so as to cover the first plating layer; a second plating layer formed to cover the first plating layer where no The first plating layer in the bent region is formed to a thickness of 0.05 to 0.25 μm.

[0020] In some embodiments of the present invention, the bending region of the flexible printed circuit board is The bent portion may have a radius of curvature of 0.01 mm to 0.49 mm.

[0021] In some embodiments of the present invention, a first region of the flexible printed circuit board and The two regions may face each other so that at least a portion of the regions contacts each other. Effect of the Invention

[0022] According to the flexible printed circuit board and the manufacturing method thereof according to the embodiment of the present invention, A first plating layer formed as a thin film on the wiring pattern in the bent area of ​​the flexible printed circuit board. By including the above, when the flexible printed circuit board is bent, the plating layer or This can prevent cracks from occurring in the wiring pattern.

[0023] In addition, a protective layer is formed on the first plating layer in the bent region, and the first plating layer on which the protective layer is not formed is By forming a second plating layer having a sufficient thickness on the plating layer, This ensures a strong bond between the printed circuit board and the circuit element or electronic device.

[0024] The effects of the present invention are not limited to the above-mentioned effects, and other effects not described above are as set forth in the claims. This will be clearly understood by those skilled in the art from the description. [Brief description of the drawings]

[0025] [Figure 1] 1 is a top view illustrating a flexible printed circuit board according to an embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view taken along line AA' in FIG. [Diagram 3] 2 is a cross-sectional view taken along the line BB' in FIG. [Figure 4] 1 is a graph showing bending test results of a flexible printed circuit board according to an embodiment of the present invention. [Diagram 5] FIG. 11 is a cross-sectional view of a flexible printed circuit board according to another embodiment of the present invention. [Figure 6] 1 is a cross-sectional view of an electronic device including a flexible printed circuit board according to an embodiment of the present invention. [Figure 7] 7 is an enlarged view showing a bending region of a flexible printed circuit board included in the electronic device of FIG. 6. FIG. [Figure 8] 1A to 1C are views illustrating intermediate stages of a method for manufacturing a flexible printed circuit board according to an embodiment of the present invention. [Figure 9] 1A to 1C are views illustrating intermediate stages of a method for manufacturing a flexible printed circuit board according to an embodiment of the present invention. [Figure 10] 1A to 1C are views illustrating intermediate stages of a method for manufacturing a flexible printed circuit board according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The advantages, features and methods of achieving the same of the present invention will be described in detail below with reference to the accompanying drawings. The invention will be elucidated with reference to the embodiments disclosed below. However, the present invention is not limited to the above embodiment and may be embodied in many different forms. The above disclosure is provided solely for the purpose of completeness and is not intended to be limiting of the invention to those skilled in the art. The present invention is provided in order to fully inform those having ordinary skill in the art of the scope of the invention. The dimensions and relative sizes of the elements shown are for illustrative purposes only. The figures may be exaggerated for clarity. The reference numbers refer to the same components, and "and / or" refers to each and every listed item. Includes all combinations of one or more.

[0027] Describing elements or layers as being "on" other elements or layers If they are directly on top of other elements or layers, or if there is another layer between them, This includes all cases where an element is "directly on" the When a device is described as being "directly on" or "directly above," there must be another element or This indicates that there is no intervening layer.

[0028] The spatially relative terms "below" and "beneath" "ower," "above," "upper," etc. are used as shown in the figure. The relationship between one element or component and another element or component can be easily described. Spatially relative terms can be used in addition to the illustrated directions. It should be understood as a term that encompasses different orientations of an element during operation or performance. For example, if an element is inverted as shown, it may be “below” or “beneath” the other element. An element described as "above" another element may be located "above" another element. Thus, the exemplary term "below" can encompass both an orientation of below and above. Other orientations are possible, in which case the spatially relative terms should be interpreted accordingly.

[0029] The terms used in this specification are intended to describe the embodiments and are not intended to limit the present invention. In this specification, the singular forms "a," "an," and "the" refer to the plural forms unless the context clearly indicates otherwise. In addition, "comprise" and / or "comprising" are used interchangeably. This does not exclude the presence or addition of one or more other components in addition to the components listed.

[0030] Although terms such as "first," "second," etc. are used to describe various elements or components, However, these elements or components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, the first element or component referred to below is within the technical concept of the present invention. It may also be the second element or component.

[0031] Unless otherwise defined, all terms used herein, including technical and scientific terms, (including the above) are commonly understood by those having ordinary skill in the art to which the present invention pertains. In addition, terms defined in commonly used dictionaries may be used without ambiguity. Unless specifically defined, they are not to be interpreted ideally or excessively.

[0032] FIG. 1 is a top view illustrating a flexible printed circuit board according to an embodiment of the present invention. 2 and 3 are cross-sectional views taken along lines AA' and BB' in FIG. 1, respectively.

[0033] 1 to 3, a flexible printed circuit board 1 according to an embodiment of the present invention is , a base film 10, first wiring patterns 20, 21, first protective layers 30, 31, a first plating The second plating layer 50 may include a platinum layer 40 and a second plating layer 50 .

[0034] The base film 10 can be made of a flexible material and is attached to the flexible printed circuit board 1. It is included as a base material and allows the flexible printed circuit board 1 to bend or break. .

[0035] The base film 10 includes a bending region 100, a first region 101, and a second region 102. The bending region 100 can be disposed between the first region 101 and the second region 102. When the flexible printed circuit board 1 is mounted on an electronic device, the bending region 100 is bent. On the other hand, the first area 101 and the second area 102 may be areas where the flexible printed circuit board is mounted as it is. This may be a region that is not bent when the flexible printed circuit board 1 is mounted in an electronic device.

[0036] The base film 10 may be, for example, a polyimide film. The base film 10 is made of PET (Polyethylene Terephthalate). ) film, polyethylene naphthalate film, polycarbonate film, etc. It may be a film or a metal foil such as aluminum oxide foil. In the flexible printed circuit board 1 according to the present invention, the base film 10 is a polyimide film. He explains that this is the case.

[0037] The base film 10 can have insulating properties. A flexible printed circuit board according to another embodiment of the present invention (FIG. 4-2) has wiring patterns on both sides. When the wiring patterns 20 and 120 are formed, the wiring patterns 20 and 120 are not electrically connected to each other. Thus, it can be insulated.

[0038] However, the present invention is not limited to this. The base film 10 may be provided with a Vias (not shown) may also be included to electrically connect the line patterns 20, 120.

[0039] The base film 10 may include an element placement area 12. The element placement area 12 may include: This may be an area in which a circuit element electrically connected to the flexible printed circuit board 1 is disposed. .

[0040] A plurality of first wiring patterns 20 can be formed on the base film 10. The pattern 20 may be, for example, a wiring pattern formed in a strip shape having a certain width. The first wiring pattern 20 can be formed continuously at a predetermined interval on one surface of the base film 10. do.

[0041] The first wiring pattern 20 can include a conductive material such as a metal. The wiring pattern 20 is a conductive wiring for transmitting an electric signal or a static electricity generated by touch. It may be a transparent conductive wiring for transmitting capacitance. More specifically, the first wiring pattern 20 may include a conductive material such as copper, although the invention is not limited thereto. In addition, the first wiring pattern 20 may also include materials such as gold and aluminum.

[0042] As shown in FIG. 2 and FIG. 3, a flexible print according to an embodiment of the present invention is The first wiring pattern 20 of the substrate can be formed in one layer, but the present invention is not limited to this. The flexible printed circuit board 1 may include two or more multilayer printed wiring layers. do.

[0043] The first wiring patterns 20 and 21 may include an element connection portion 15. can overlap with the element placement region 12 of the base film 10.

[0044] The element connection portion 15 is a terminal that is electrically connected to a circuit element arranged on the element arrangement region 12. That is, the element connection portion 15 may include a chip-on-film (COF) or or Film On Glass (FOG) method to mount circuit elements In this case, it may be a terminal formed on the first wiring pattern 20. For example, semiconductor chips IC, sensors, light emitting diodes LED, etc. It may include, but the invention is not limited thereto.

[0045] A first plating layer 40 may be formed on the first wiring patterns 20. The first plating layer 40 may include The first plating layer 40 may be formed to cover the upper and side surfaces of the first wiring pattern 20. The thickness of the first plating layer 40 can be 0.05 to 0.25 μm. This will be explained with reference to Table 1.

[0046] FIG. 4 shows the results of a bending test of the flexible printed circuit board 1 according to one embodiment of the present invention. 4 is a graph, and Table 1 is a table showing the bending test results of FIG. 4 in numerical form.

[0047] [Table 1]

[0048] In the flexible printed circuit board according to the embodiment of the present invention, the thickness of the first plating layer 40 is After forming the flexible printed circuit board so that the thickness is 0.05 to 0.5 μm, the bending area A bending test was carried out by repeatedly bending the area 100. The number of times when the first crack occurred was recorded and is shown in Table 1 and FIG.

[0049] As can be seen from Table 1 and FIG. 4, the thickness of the first plating layer 40 is 0.05, 0.1, 0 When the thickness was 0.15, 0.2, and 0.25 μm, the first cracks occurred at 381 and 35 μm, respectively. 4, 302, 252, and 179 times. In other words, the thickness of the first plating layer 40 was 0. 0.5μm, the resistance to cracks on the wiring pattern is the highest in bending tests. In addition, about 30 to 50 initial cracks are required for each 0.05 μm increase in thickness of the first plating layer 40. There was a decrease in the number of occurrences of

[0050] However, when the thickness of the first plating layer 40 is 0.3 μm, the number of cracks that first occurred was 4. The thickness of the first plating layer 40 starts to decrease rapidly three times, from 0.35, 0.4, 0. When the thickness was 45 and 0.5 μm, the first crack occurred after 17 times, 5 times, 1 time, and 1 time, respectively. was observed.

[0051] Therefore, the first plating layer 4 of the flexible printed circuit board 1 according to the embodiment of the present invention The first plating layer 40 can be formed to a thickness of 0.05 to 0.25 μm. When the thickness is larger than 1 μm, the flexible print head is damaged as shown in the bending test results in Figure 4 and Table 1. In contrast, the bending resistance of the substrate 1 may be rapidly reduced at 0.05 Forming the first plating layer 40 to a thickness of less than 1 μm can be achieved by electrolytic plating or electroless plating. There is a risk that the first plating layer 40 formed by the plating method is not easy to plate.

[0052] Generally, the first plating layer 40 covers both the upper and side surfaces of the first wiring patterns 20. When the base film 10 is formed as described above, the first plating formed on the bent region 100 of the base film 10 The layer 40 prevents the first wiring pattern 20 from being deformed into a desired shape. This is because, as shown in the bending test results above, the first plating layer is 0. This is particularly noticeable when the first wiring pad in the bent region 100 is formed to a thickness of more than 25 μm. The tensile stress applied to the turn 20 may cause cracks in the wiring pattern or plating layer. It can increase the likelihood of it occurring.

[0053] However, in the flexible printed circuit board according to the embodiment of the present invention, the first plating layer 40 is 0. By forming the material in a thickness of .05 to .25 μm, it has been bent at least 179 times in bending tests. That is, the thickness range is as described above. By forming the first plating layer 40 thin, deformation of the first wiring pattern 20 is restricted. The flexible printed circuit board is attached to the electronic device in a bent state without bending the bending region 100. The operational reliability of the plate 1 can be improved.

[0054] The first plating layer 40 can prevent the plurality of first wiring patterns 20 from corroding. This can improve the connection between the element connection portion 15 and the circuit element connected thereto. The first plating layer 40 is made of, for example, tin (Sn), nickel (Ni), gold (Au), palladium (Pd), or the like. The material may include metals such as platinum (Pd) and aluminum (Al).

[0055] The first protective layer 30 may be formed to cover a portion of the first plating layer 40. More specifically, A first protective layer is formed on the bent region 100 of the base film 10 so as to cover the first plating layer 40. The first protective layer 30 can be formed in the bending region 100. The first region 101 or the second region 102 may be formed up to the boundary therewith. The first protective layer 30 may be formed by partially extending inside the region 102. It does not have to be formed on the element connection portion 15 of the pattern 20 .

[0056] The first protective layer 30 may include, but is not limited to, a resist ink. Instead, the first protective layer 30 may include a coverlay film.

[0057] The first protective layer 30 protects the first wiring pattern 20 from external impacts and corrosive substances. This can be done.

[0058] The second plating layer 50 may be formed to cover a portion of the first plating layer 40. Specifically, The second protective layer 30 is formed on the upper surface and the side surface of the first plating layer 40 so as to cover the upper surface and the side surface of the first plating layer 40 on which the first protective layer 30 is not formed. A plating layer 50 may be formed. The second plating layer 50 may include the same material as the first plating layer 40. It is possible.

[0059] The second plating layer 50 can be formed thicker than the first plating layer 40. The layer 40 is a crack that may occur on the first wiring pattern 20 in the bent region 100. To prevent cracks, the first plating is formed to a thickness of 0.05 to 0.25 μm. The thin thickness of the layer 40 reduces the bonding strength between the element connection portion 15 and the circuit element or electronic device. The second plating layer 50 is formed thicker than the first plating layer 40, and This can improve the bonding strength between the terminal connection portion 15 and the circuit element or electronic device.

[0060] FIG. 5 is a cross-sectional view of a flexible printed circuit board according to another embodiment of the present invention.

[0061] Referring to FIG. 5, a flexible printed circuit board 2 according to another embodiment of the present invention includes a first The wiring pattern 20 is formed on the other side of the base film 10. The second wiring pattern 120, the second protective layer 130, the third plating layer 140 and the fourth plating layer It may contain 150.

[0062] The plurality of second wiring patterns 120 are formed on a base film on which the first wiring pattern 20 is formed. The second wiring patterns 120 may be formed on the opposite side of the first wiring pattern 10. The pattern 20 may be formed at a position corresponding to the pattern 20. However, the present invention is not limited to this. Instead, a plurality of second wiring patterns 120 are arranged in parallel with a plurality of first wiring patterns according to the circuit design. It is also possible for the electrodes 20 to be arranged in a number of different shapes.

[0063] The second wiring patterns 120 are arranged continuously at predetermined intervals on the other surface of the base film 10. Similarly to the first wiring pattern 20, the second wiring pattern 21 may include a conductive material such as copper.

[0064] The first wiring pattern 20 and the second wiring pattern 120 are electrically connected by the base film 10. If necessary, the first wiring pattern 20 and the second wiring pattern 21 can be formed in the base film 10. A via (not shown) that electrically connects to the line pattern 120 may also be formed.

[0065] A third plating layer 140 may be formed to cover the second wiring pattern 120. The third plating layer 140 may cover the upper surface and side surfaces of the second wiring pattern 120. The third plating layer 140 can be formed to the same thickness as the first plating layer 40. That is, the third plating layer 140 can be formed to the same thickness as the first plating layer 40. It can be formed to a thickness of 0.05 to 0.25 μm.

[0066] When the third plating layer 140 is formed to a thickness of more than 0.25 μm, The durability against cracks that occur in the wiring pattern when bending the bending region 100 is reduced. The risk is similar to that described above regarding the first plating layer 40.

[0067] A second protective layer is formed on the bent region 100 of the base film 10 so as to cover the third plating layer 140. The second protective layer 130 may be formed on the third plating layer 140 where the second protective layer 130 is not formed. A fourth plating layer 150 can be formed.

[0068] The fourth plating layer 150 is formed thicker than the third plating layer 140. The element connection that may occur due to the formation of a thickness of 0.05 to 0.25 μm This can prevent a decrease in the bonding strength between the portion 15 and the circuit element or electronic device.

[0069] FIG. 6 is a cross-sectional view of an electronic device including a flexible printed circuit board according to some embodiments of the present invention. FIG.

[0070] Referring to FIG. 6, an electronic device 3 according to an embodiment of the present invention includes a flexible printed circuit board. The plate 5 may include a display panel 200 , a substrate 300 and driving elements 400 .

[0071] The display panel 200 and the substrate 300 are electrically connected by a flexible printed circuit board 5. The display panel 200 can display an image and is connected to a substrate 300. can generate signals for driving the display panel 200. 0 may be a PCB substrate or another flexible printed circuit board.

[0072] The driving element 400 can be disposed on a flexible printed circuit board 5. More specifically, The driving element 400 can be arranged in the element arrangement area (12 in FIG. 1) of the flexible printed circuit board 5. The driving element 400 may be, for example, a display driver IC (DDIC) that drives a display panel. ay Driver IC).

[0073] Here, the display panel 200, the substrate 300, the driving element 400, etc. are flexible. These are exemplary circuit elements that can be connected to the printed circuit board 5, and the present invention is not limited thereto. That is, in the electronic device 3 of the present invention, the flexible printed circuit board 5 is It is possible in any case where the wire is bent to form a It is understood that the above is obvious to a person having ordinary skill in the art. It will be possible to do so.

[0074] The flexible printed circuit board 5 includes a bending region 500, a first region 501, and a second region 50 It may contain 2.

[0075] The first region 501 is connected to the display panel 200. Although not shown, the first region 501 may extend parallel to the connection surface of the disk. It may include a terminal portion that is connected to the spray panel 200.

[0076] The second region 502 is connected to the substrate 300 and extends parallel to the connection surface with the substrate 300. Similarly, the second region 502 may include a terminal portion that is connected to the substrate 300. do.

[0077] As shown in the figure, the first region 501 and the second region 502 of the flexible printed circuit board 5 are However, the present invention is not limited to this. That is, the first region 501 and the second region 502 are not in contact with each other at least partially. That is, the flexible printed circuit board 5 may be arranged so that the bending region 500 is the base. It can be attached to the electronic device 3 while folded into a directrix.

[0078] The bending region 500 connects the first region 501 and the second region 502 and is bent at an angle of 90 degrees to 180 degrees. The angle can be adjusted to .theta..times ...

[0079] The bending region 500, the first region 501 and the second region 502 of the flexible printed circuit board 5 are 1, the bending region 100 included in the base film 10 of the flexible printed circuit board 1 of FIG. These can correspond to a first region 101 and a second region 102, respectively.

[0080] FIG. 7 is an enlarged view of a bending region of a flexible printed circuit board included in the electronic device of FIG. FIG.

[0081] Referring to FIG. 7, a bending region 500 of a flexible printed circuit board has a predetermined radius of curvature r The electronic device 3 can be attached while holding the electronic device 3.

[0082] The flexible printed circuit board 5 according to the embodiment of the present invention is attached to the electronic device 3 in a bent state. When mounted, the total thickness D1 of the flexible printed circuit board 5 is 0.1 mm to 1 mm. could be.

[0083] As an example of a flexible printed circuit board according to an embodiment of the present invention, The total thickness D1 of the substrate 5 may be 0.2 mm, and the cross-sectional thickness D2 may be 0.071 mm. In this case, the radius of curvature r of the bending region of the flexible printed circuit board 5 is 0.029 mm. Such a radius of curvature r of the bent region 500 is merely an example and may be used in some embodiments of the present invention. The radius of curvature of the bent region in the flexible printed circuit board according to the embodiment is 0.01 mm to 0 It can become .49mm.

[0084] 8 to 10 illustrate a method for manufacturing a flexible printed circuit board according to an embodiment of the present invention. This is an intermediate stage diagram for clarity.

[0085] Referring to FIG. 8, a plurality of first wiring patterns 20 are formed on one surface of a base film 10. The formation of the plurality of first wiring patterns 20 may be carried out, for example, by sputtering a conductive material. After being formed on one side of the base film 10 by a coating method or a lamination method, Alternatively, a conductive material may be printed on the base film 10. can.

[0086] In FIG. 8, a plurality of first wiring patterns 20 are formed only on one surface of the base film 10. However, the present invention is not limited to this. In the flexible printed circuit board 2 according to the embodiment, the opposite side of the base film 10 is A second wiring pattern 120 can also be formed on the other surface.

[0087] Referring to FIG. 9, a first plating layer 40 is formed to cover a plurality of first wiring patterns 20. It can be achieved.

[0088] The first plating layer 40 may be, for example, tin, nickel, gold, palladium, and aluminum. A metal material such as aluminum is deposited on the first conductive pattern 20 by electrolytic plating or electroless plating. The thickness of the film can be 0.05 to 0.25 μm.

[0089] Referring to FIG. 10, a first protective layer 40 is formed on the bent region 100 to cover the first plating layer 40. The first protective layer 30 can be formed by applying a resist ink. However, the present invention is not limited to this, and a solder resist or a coverlay film may be used. It may be formed by lamination.

[0090] Referring again to FIG. 3, the first plating layer 40 on which the first protective layer 30 is not formed is The second plating layer 40 is formed. The second plating layer 40 is made of tin, nickel, as in the first plating layer 30. Metallic materials such as gold, palladium and aluminum are electrolytically plated or The element connection portion 15 can be formed by electrolytic plating. In order to ensure sufficient bonding strength, the second plating layer 40 can be formed thicker than the first plating layer 30. do.

[0091] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these embodiments. The present invention is not limited to the above embodiment, and may be produced in various different forms. A person having ordinary skill in the art would be able to modify the technical idea or essential features of the present invention. It will be understood that the present invention may be embodied in other specific forms without departing from the spirit and scope of the present invention. It should be understood that the above-described embodiments are illustrative in all respects and are not limiting. It is.

Claims

1. A base film including a bending region, a first region, and a second region, the bending region being A base film disposed between the first region and the second region; A plurality of first wiring patterns formed on one surface of the base film; a first plating layer covering the first wiring patterns; A first protective layer is formed on the bent region of the base film to cover the first plating layer. The protective layer, A second plating layer is formed to cover the first plating layer where the first protective layer is not formed. A layer of The first plating layer on the bent region is formed to a thickness of 0.05 to 0.25 μm. Flexible printed circuit board.

2. the first wiring pattern includes an element connection portion, The flexible substrate according to claim 1 , wherein the first protective layer is not formed on the element connection portion. Printed circuit board.

3. The flexible printed circuit board according to claim 2 , wherein the second plating layer is formed so as to cover the element connection portion. Simplified printed circuit board.

4. A plurality of second wiring patterns are formed on the other surface of the base film, which is the opposite surface of the one surface. And, a third plating layer covering the second wiring pattern; A second protective layer is formed on the bent region of the base film to cover the third plating layer. The protective layer, A third plating layer is formed to cover the third plating layer where the second protective layer is not formed. The flexible printed circuit board according to claim 1 , further comprising a metal layer.

5. 5. The method according to claim 4, wherein the third plating layer is formed to a thickness of 0.05 to 0.25 μm. Flexible printed circuit board.

6. The first wiring pattern and the second wiring pattern are electrically connected to the inside of the base film. The flexible printed circuit board according to claim 4 , further comprising a via for connecting the wiring layers to each other.

7. The flexible printed circuit board according to claim 1 , wherein the second plating layer is formed to be thicker than the first plating layer. Simplified printed circuit board.

8. A base film is provided that includes a bending region, a first region, and a second region, the bending region being a front disposed between the first region and the second region; forming a plurality of first wiring patterns on one surface of the base film; forming a first plating layer to cover the first wiring patterns; A first protective layer is formed on the bent region of the base film to cover the first plating layer. death, A second plating layer is formed to cover the first plating layer where the first protective layer is not formed. This includes: The first plating layer on the bent region is formed to a thickness of 0.05 to 0.25 μm. A manufacturing method for flexible printed circuit boards.

9. A plurality of second wiring patterns are formed on the other surface of the base film, the other surface being the opposite surface of the one surface. death, forming a third plating layer to cover the second wiring patterns; A second protective layer is formed on the bent region of the base film to cover the third plating layer. death, A fourth plating layer is formed to cover the third plating layer where the second protective layer is not formed. The method for manufacturing a flexible printed circuit board according to claim 8 , further comprising:

10. The second plating layer is formed to have a thickness greater than that of the first plating layer. The method for producing a flexible printed circuit board according to claim 8 , comprising:

11. a first circuit element and a second circuit element; and a first region connected to the first circuit element and extending parallel to a connection surface with the first circuit element; a second region connected to the second circuit element and extending parallel to a connection surface with the second circuit element; The first region and the second region are connected to form a bending region that can be bent at an angle of 90 degrees to 180 degrees. A flexible printed circuit board including: The flexible printed circuit board is Base film, A plurality of wiring patterns formed on at least one surface of the base film; a first plating layer formed to cover the plurality of wiring patterns; a first protective layer formed in the bent region to cover the first plating layer; and A second plating layer is formed to cover the first plating layer where the first protective layer is not formed. Including the Ki layer, The first plating layer in the bent region is formed to a thickness of 0.05 to 0.25 μm. Child device.

12. The bending area of ​​the flexible printed circuit board has a radius of curvature of 0.01 mm to 0.49 mm. The electronic device of claim 11 , wherein the electronic device is bent such that

13. At least a portion of the first region and the second region of the flexible printed circuit board are in contact with each other. The electronic device of claim 11 , wherein the electronic device is opposed to the outside of the housing so as to be in contact with the outside of the housing.

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