JP2020127054A - Flexible printed circuit board, electronic device including the same, and method for manufacturing flexible printed circuit board - Google Patents

Abstract

To provide a flexible printed circuit board including a plated layer formed as a thin film in a bending region, thereby improving product reliability, and a manufacturing method therefor.SOLUTION: A flexible printed board 1 includes a base film 10 which includes a bending region, a first region and a second region and in which the bending region is arranged between the first region and the second region, a plurality of first wiring patterns 20 formed on one surface of the base film 10, a first plated layer 40 that covers the plurality of first wiring patterns 20, a first protective layer 30 which is formed on the bending region of the base film 10 so as to cover the first plated layer, and a second plated layer 50 which is formed so as to cover the first plated layer 40 on which the first protective layer 30 is not formed. The first plated layer on the bending region is formed to have a thickness of 0.05 to 0.25 μm.SELECTED DRAWING: Figure 3

Description

The present invention relates to a flexible printed board, an electronic device including the same, and a method for manufacturing the flexible printed board.

Recently, with downsizing of electronic devices, a chip-on-film (COF) package technology using a flexible printed circuit board has been used. The flexible printed circuit board and the COF packaging technology using the flexible printed circuit board are, for example, liquid crystal display devices (Li
liquid crystal display (LCD) and organic light-emitting diode (Orga)
It is used for a flat panel display device (Flat Panel Display, FPD) such as a nic light emitting diode display device.

Since the flexible printed circuit board is flexible, it may be bent or bent when used in electronic devices.If the flexible printed circuit board is bent and used, the flexible printed circuit board may be bent at the bent portion. Durability may decrease.

In particular, after forming the conductive wiring pattern, a plating layer is formed to protect the wiring pattern or to secure the bonding force with the electronic component.The plating layer may be formed on the wiring pattern and the plating layer during plating or after plating. Alloy layer (IMC layer) formed by diffusing substances contained in each other
Since this alloy layer has a hardness relatively higher than that of the wiring pattern, the alloy layer may be less flexible and may cause cracks mainly when the flexible printed board is bent.

On the other hand, in order to prevent the occurrence of cracks in the bent portion of the flexible printed circuit board, it is preferable to form a plating layer on the terminal portion after forming a protective layer that covers the wiring pattern after forming the wiring pattern. At this time, there is a possibility that a cavity may be formed at the boundary between the protective layer and the plated layer due to a local battery phenomenon. As a solution to this problem, Korean Patent Publication No. 2000-62154 (hereinafter referred to as "prior art 1") is disclosed. However, the prior art 1 is for preventing the local battery phenomenon, and does not consider the circuit defect in the bent portion of the flexible printed circuit board, and therefore still includes the risk of the circuit defect in the bent portion.

A technical problem to be solved by the present invention is to provide a flexible printed circuit board including a plating layer formed as a thin film in a bending region to improve reliability of a product, and an electronic device including the same.

Another technical problem to be solved by the present invention is to provide a method for manufacturing a flexible printed circuit board in which the reliability of the product is improved by including a plating layer formed as a thin film in the bending region.

The technical problem of the present invention is not limited to the technical problem described above, and other technical problems not described above will be clearly understood by those skilled in the art from the following description.

A flexible printed circuit board according to an embodiment of the present invention for achieving the above technical problem is a base film including a bending region, a first region and a second region, and the bending region is the first region. A base film disposed between the second region, a plurality of first wiring patterns formed on one surface of the base film, a first plating layer covering the plurality of first wiring patterns, and the base A first protective layer formed on the bent region of the film so as to cover the first plated layer, and a second plated formed so as to cover the first plated layer on which the first protective layer is not formed. The first plating layer on the bending region is 0.05-0.
It is formed to a thickness of 25 μm.

In some embodiments of the present invention, the first wiring pattern may include an element connecting portion, and the first protective layer may not be formed on the element connecting portion.

In some embodiments of the present invention, the second plating layer may be formed so as to cover the element connecting portion.

In some embodiments of the present invention, a plurality of second wiring patterns formed on the other surface of the base film opposite to the one surface, a third plating layer covering the second wiring pattern, and A second layer formed on the bent region of the base film so as to cover the third plating layer;
The method may further include a protection layer and a third plating layer formed to cover the third plating layer on which the second protection layer is not formed.

In some embodiments of the present invention, the third plating layer may have a thickness of 0.05 to 0.25 μm.

In some embodiments of the present invention, the base film may further include a via electrically connecting the first wiring pattern and the second wiring pattern.

In some embodiments of the present invention, the second plating layer may be formed thicker than the first plating layer.

A method for manufacturing a flexible printed circuit board according to an embodiment of the present invention for achieving the above technical problem provides a base film including a bending region, a first region, and a second region. A plurality of first wiring patterns are formed on one surface of the base film and are disposed between the first region and the second region, and a first plating layer is formed to cover the plurality of first wiring patterns. A first protective layer is formed on the bent region of the base film so as to cover the first plated layer, and a second plated layer is formed so as to cover the first plated layer on which the first protective layer is not formed. And forming the first plating layer on the bending region in an amount of 0.05 to 0.
． It is formed to a thickness of 25 μm.

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

In some embodiments of the present invention, forming the second plating layer may include forming the second plating layer thicker than the first plating layer.

An electronic device according to an embodiment of the present invention for achieving the above technical problem includes a first circuit element and a second circuit element; and a first circuit element connected to the first circuit element. A first region extending parallel to the connection surface, a second region connected to the second circuit element and extending parallel to the connection face with the second circuit element, and connecting the first region and the second region, A flexible printed circuit board including a bending region bent at an angle of 90 to 180 degrees; the flexible printed circuit board includes a base film, a plurality of wiring patterns formed on at least one surface of the base film, and the plurality of wirings. A first plating layer formed to cover the pattern, a first protective layer formed to cover the first plating layer in the bending region, and the first plating not formed to the first protective layer The first plating layer in the bending region may be formed to have a thickness of 0.05 to 0.25 μm, including a second plating layer formed to cover the layer.

In some embodiments of the present invention, the bending area of the flexible printed circuit board may be bent to have a radius of curvature of 0.01 mm to 0.49 mm.

In some embodiments of the present invention, at least a part of the first area and the second area of the flexible printed circuit board may be opposed to each other.

According to the flexible printed circuit board and the manufacturing method thereof according to the embodiment of the present invention, by including the first plating layer formed as a thin film on the wiring pattern in the bending region of the flexible printed circuit board, the flexible printed circuit board can be bent. At this time, it is possible to prevent cracks generated in the plating layer or the wiring pattern due to the tension.

In addition, a protective layer is formed on the first plating layer in the bending region, and the first plating layer without the protective layer is formed.
By forming the second plating layer having a sufficient thickness on the plating layer, it is possible to secure the bonding force between the flexible printed board and the circuit element or the electronic device.

The effects of the present invention are not limited to the effects described above, and other effects not described above will be clearly understood by those skilled in the art from the description of the claims.

It is a top view for explaining the flexible printed circuit board concerning one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line A-A′ of FIG. 1. FIG. 2 is a sectional view taken along line B-B′ of FIG. 1. It is a graph which shows the bending test result of the flexible printed circuit board concerning one embodiment of the present invention. It is sectional drawing of the flexible printed circuit board which concerns on other embodiment of this invention. 1 is a cross-sectional view of an electronic device including a flexible printed board according to an exemplary embodiment of the present invention. FIG. 7 is an enlarged view showing a bending region of a flexible printed circuit board included in the electronic device of FIG. 6. FIG. 6 is an intermediate stage diagram illustrating a method for manufacturing a flexible printed circuit board according to an exemplary embodiment of the present invention. FIG. 6 is an intermediate stage diagram illustrating a method for manufacturing a flexible printed circuit board according to an exemplary embodiment of the present invention. FIG. 6 is an intermediate stage diagram illustrating a method for manufacturing a flexible printed circuit board according to an exemplary embodiment of the present invention.

Advantages, features, and methods of achieving the same of the present invention will become apparent with reference to the embodiments described in detail below in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be implemented in various forms different from each other. However, the present embodiment is provided merely to complete the disclosure of the present invention and to fully inform the person having ordinary knowledge in the technical field to which the present invention belongs to the category of the present invention. The invention is defined only by the scope of the claims. The size and relative size of the illustrated components may be exaggerated for clarity of explanation. Throughout the specification, the same reference numerals refer to the same components, and "and/or" includes each and every combination of one or more of the listed items.

When an element or layer is described as being "on" another element or layer, it is not limited to being immediately above the other element or layer, but also between other elements or layers. Includes all cases in which a layer or another element is interposed. In contrast, the device is "directly above (direct
ly on)” or “directly above” indicates that no other element or layer is interposed between them.

The spatially relative terms "below (below or beneath)", "below (l
",""above,""upper," etc., are used to describe easily the correlation between one element or component and another element or component, as shown. Can be used for Spatial relative terms are to be understood as including terms in addition to the directions shown, but also in different directions of the element in use or in operation. For example, when overriding an illustrated element, it is “below” or “below” another element.
Elements described as "h)" may be located "above" other elements.
Thus, the exemplary term "below" can encompass both an orientation of above and below. The elements can also be oriented in other directions. In this case, spatially relative terms can be interpreted depending on the orientation.

The terminology used herein is for the purpose of describing the embodiments and not for limiting the invention. In this specification, the singular forms also include the plural unless the context otherwise requires. Also, "comprises and/or comprising" does not exclude the presence or addition of one or more other components in addition to the listed components.

Although terms such as "first", "second", etc. are used to describe various elements or components, it should be understood that these elements or components are not limited by these terms. These terms are only used to distinguish one element from another. Therefore, the first element or component referred to below may be the second element or component within the technical concept of the present invention.

Unless defined otherwise, all terms (including technical and scientific terms) used herein have the meaning commonly understood by one of ordinary skill in the art to which this invention belongs. Can be used in. Also, commonly used dictionary-defined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

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

1 to 3, a flexible printed circuit board 1 according to an exemplary embodiment of the present invention includes a base film 10, first wiring patterns 20, 21, first protective layers 30, 31, a first plating layer 40, and a first plating layer 40. Two plating layers 50 may be included.

The base film 10 can be formed of a flexible material and is included in the flexible printed circuit board 1 as a base material so that the flexible printed circuit board 1 can be bent or bent.

The base film 10 may include a bent region 100, a first region 101 and a second region 102. The bending region 100 can be arranged 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 may be a region that is mounted while being bent. On the other hand, the first area 101 and the second area 102 may be areas that are not bent when the flexible printed circuit board 1 is mounted on an electronic device.

The base film 10 can be, for example, a polyimide film. Unlike this, the base film 10 is made of PET (Polyethylene Terephthalate).
) A film, an insulating film such as a polyethylene naphthalate film or a polycarbonate film, or a metal foil such as an aluminum oxide foil may be used. In the flexible printed circuit board 1 according to the embodiment of the present invention, the base film 10 will be described as a polyimide film.

The base film 10 can have an insulating property. That is, as will be described later, when the wiring patterns 20 and 120 are formed on both surfaces of the flexible printed circuit board (2 in FIG. 4) according to another embodiment of the present invention, the wiring patterns 20 and 120 are electrically connected to each other. It can be insulated to prevent it.

However, the present invention is not limited to this, and the base film 10 may include vias (not shown) for electrically connecting the wiring patterns 20 and 120 therein.

The base film 10 may include the element arrangement area 12. The element placement region 12 is
It may be a region in which circuit elements electrically connected to the flexible printed circuit board 1 are arranged.

The plurality of first wiring patterns 20 can be formed on the base film 10. The first wiring pattern 20 may be, for example, a wiring pattern formed in a strip shape having a constant width. The plurality of first wiring patterns 20 can be continuously formed on one surface of the base film 10 at predetermined intervals.

The first wiring pattern 20 may include a conductive material such as metal. Specifically, the first wiring pattern 20 may be a conductive wiring for transmitting an electric signal or a transparent conductive wiring for transmitting a capacitance due to touch. More specifically, the first wiring pattern 20 may include a conductive material such as copper, but the present invention is not limited to this. The first wiring pattern 20 includes a material such as gold or aluminum. It can also be included.

As shown in FIGS. 2 and 3, the first wiring pattern 20 of the flexible printed circuit board according to the embodiment of the present invention can be formed in one layer, but the present invention is not limited thereto. .. The flexible printed board 1 may include a multilayer printed wiring having two or more layers.

The first wiring patterns 20 and 21 may include the element connecting portion 15. Element connection part 15
Can be overlapped with the element arrangement region 12 of the base film 10.

The element connecting portion 15 may include a terminal electrically connected to a circuit element arranged on the element arrangement region 12. That is, the element connecting portion 15 may be a terminal formed on the first wiring pattern 20 when a circuit element is mounted by a chip on film (COF) or film on glass (Film On Glass, FOG) method. Such a circuit element may include, for example, a semiconductor chip IC, a sensor, a light emitting diode LED, etc., but the present invention is not limited thereto.

The first plating layer 40 may be formed on the plurality of first wiring patterns 20. The first plating layer 40 may be formed to cover the upper surface and the side surface of the first wiring pattern 20. The first plating layer 40 is 0
． It can be formed to a thickness of 05 to 0.25 μm. The thickness of the first plating layer 40 will be described with reference to FIG. 4 and Table 1.

FIG. 4 is a graph showing the results of the bending test of the flexible printed circuit board 1 according to the embodiment of the present invention, and Table 1 is a table showing the bending test results of FIG.

In the flexible printed circuit board according to an embodiment of the present invention, a method of repeatedly bending the bending region 100 of the flexible printed circuit board after forming the first plating layer 40 to have a thickness of 0.05 to 0.5 μm. The bending test was conducted at. After that, the number of times that a crack is first generated in the wiring pattern 20 is recorded and shown in Table 1 and FIG. 4, respectively.

As can be seen from Table 1 and FIG. 4, the thickness of the first plating layer 40 is 0.05, 0.1, 0.
． At 15, 0.2 and 0.25 μm, the initial cracks were 381 and 35, respectively.
4, 302, 252, 179 times. That is, the thickness of the first plating layer 40 is 0.
When the thickness is 05 μm, the durability against cracking on the wiring pattern is highest in the bending test, and the number of initial cracking is reduced by about 30 to 50 times each time the thickness of the first plating layer 40 increases by 0.05 μm. Appeared.

However, when the thickness of the first plating layer 40 is 0.3 μm, the number of crack occurrences is 4
The thickness of the first plating layer 40 is 0.35, 0.4, 0.
At 45 and 0.5 μm, cracking was first observed 17 times, 5 times, 1 time, and 1 time, respectively.

Therefore, the first plating layer 4 of the flexible printed circuit board 1 according to the embodiment of the present invention.
0 can be formed to a thickness of 0.05 to 0.25 μm. The thickness of the first plating layer 40 is 0.25
If it is larger than μm, the bending resistance of the flexible printed circuit board 1 may drastically decrease as shown in the bending test result shown in FIG. 4 and Table 1. On the other hand, 0.05
Forming the first plating layer 40 to a thickness smaller than μm may not facilitate the plating of the first plating layer 40 formed by electrolytic plating or electroless plating.

Generally, when the first plating layer 40 is formed so as to cover both the upper surface and the side surface of the plurality of first wiring patterns 20, the first plating layer 40 formed on the bending region 100 of the base film 10 causes There is a possibility that a problem may occur that the one wiring pattern 20 is prevented from being deformed into a desired shape. This is because the first plating layer has a thickness of 0.
Although it becomes particularly noticeable when it is formed to be thicker than 25 μm, it is possible to increase the possibility that cracks may occur on the wiring pattern or the plating layer due to the tensile stress applied to the first wiring pattern 20 in the bending region 100. ..

However, in the flexible printed circuit board according to the exemplary embodiment of the present invention, the first plating layer 40 may be omitted.
． When formed to have a thickness of 05 to 0.25 μm, it can have durability against bending of at least 179 times in a bending test. That is, by forming the first plating layer 40 thin so as to have the above-described thickness range, the bending area 100 is bent in the electronic device without limiting the deformation of the first wiring pattern 20. The operational reliability of the mounted flexible printed circuit board 1 can be improved.

The first plating layer 40 can prevent the plurality of first wiring patterns 20 from corroding, and can improve the bondability between the element connecting portion 15 and the circuit element connected thereto.
The first plating layer 40 may include a metal such as tin (Sn), nickel (Ni), gold (Au), palladium (Pd), and aluminum (Al).

The first protective layer 30 may be formed so as to cover a part of the first plating layer 40. More specifically, the first protective layer 30 may be 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 is formed in the bending region 100 such that
The boundary with the region 101 or the second region 102 can be formed, but the first region 101 or the second region 102 can be formed.
It may be formed by partially expanding inside the region 102. On the other hand, the first protective layer 30 may not be formed on the element connecting portion 15 of the first wiring pattern 20.

The first protective layer 30 may include, for example, a resist ink, but is not limited thereto. The first protective layer 30 may include a coverlay film.

The first protective layer 30 can protect the first wiring pattern 20 from external impacts and corrosive substances.

The second plating layer 50 may be formed so as to cover a part of the first plating layer 40. In particular,
The second plating layer 40 is formed so as to cover the upper surface and the side surface of the first plating layer 40 on which the first protection layer 30 is not formed.
The plating layer 50 can be formed. The second plating layer 50 may include the same material as the first plating layer 40.

The second plating layer 50 can be formed thicker than the first plating layer 40. That is, the first plating layer 40 is formed to have a thickness of 0.05 to 0.25 μm in order to prevent cracks that may occur on the first wiring pattern 20 in the bending region 100. Due to the thin thickness of the plated layer 40, there is a possibility that the joint strength between the element connecting portion 15 and the circuit element or the electronic device may be reduced. The second plating layer 50 is formed to be thicker than the first plating layer 40, and can improve the bonding force with the circuit element or the electronic device in the element connection portion 15.

FIG. 5 is a sectional view of a flexible printed circuit board according to another embodiment of the present invention.

Referring to FIG. 5, a flexible printed circuit board 2 according to another exemplary embodiment of the present invention is a first embodiment.
A second wiring pattern 120, a second protective layer 130, a third plating layer 140, and a fourth plating layer 150, which are formed on the other surface of the base film 10 on which the wiring pattern 20 is formed and which is opposite to the one surface. You can

The plurality of second wiring patterns 120 may be formed on the opposite surface of the base film 10 on which the first wiring patterns 20 are formed. The plurality of second wiring patterns 120 may be formed at positions corresponding to the plurality of first wiring patterns 20. However, the present invention is not limited to this, and the plurality of second wiring patterns 120 may be arranged in a shape different from that of the plurality of first wiring patterns 20 depending on the circuit design. ..

The plurality of second wiring patterns 120 may be continuously formed on the other surface of the base film 10 at predetermined intervals, and may include a conductive material such as copper, like the first wiring pattern 20.

The first wiring pattern 20 and the second wiring pattern 120 can be electrically insulated by the base film 10. If necessary, a via (not shown) may be formed in the base film 10 to electrically connect the first wiring pattern 20 and the second wiring pattern 120.

The 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 the side surface of the second wiring pattern 120. Third plating layer 1
40 can be formed to have the same thickness as the first plating layer 40. That is, the third plating layer 140 may be formed to a thickness of 0.05 to 0.25 μm.

If the third plating layer 140 is formed to be thicker than 0.25 μm, the durability against cracks generated in the wiring pattern when the bending region 100 of the base film 10 is bent may be lowered first. This is the same as described for the 1-plated layer 40.

A second protective layer 130 may be formed in the bent region 100 of the base film 10 so as to cover the third plated layer 140, and a fourth plated layer may be formed on the third plated layer 140 where the second protective layer 130 is not formed. 150 can be formed.

The fourth plating layer 150 is formed thicker than the third plating layer 140, and
It is possible to prevent a decrease in the bonding force with the circuit element or the electronic device in the element connecting portion 15, which may occur due to the formation of a thickness of 0.05 to 0.25 μm.

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.

Referring to FIG. 6, the electronic device 3 according to an exemplary embodiment of the present invention may include a flexible printed circuit board 5, a display panel 200, a substrate 300, and a driving element 400.

The display panel 200 and the substrate 300 can be electrically connected by the flexible printed circuit board 5. The display panel 200 can display an image, and the substrate 300
Can generate a signal for driving the display panel 200. Board 30
0 may be a PCB board or another flexible printed board.

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

Here, the display panel 200, the substrate 300, the driving element 400, etc. are exemplary circuit elements that can be connected to the flexible printed circuit board 5, and the present invention is not limited thereto. That is, in the electronic device 3 of the present invention, it is possible in any case as long as the flexible printed circuit board 5 is bent at a predetermined angle to be connected to the circuit element, which is common in the technical field. You will understand that it is obvious to those who have knowledge of.

The flexible printed circuit board 5 includes a bending area 500, a first area 501 and a second area 50.
2 can be included.

The first area 501 is connected to the display panel 200, and
Can extend parallel to the connecting surface with. Although not shown, the first region 501 may include a terminal unit connected to the display panel 200.

The second region 502 may be connected to the substrate 300 and may extend in parallel with a connection surface with the substrate 300. Similarly, the second region 502 may include a terminal portion connected to the substrate 300.

As shown, the first area 501 and the second area 502 of the flexible printed circuit board 5 can be mounted on the electronic device 3 so as to face each other with a space therebetween, but the present invention is not limited thereto. That is, at least a part of the first area 501 and the second area 502 may be opposed to each other. That is, the flexible printed circuit board 5 can be mounted on the electronic device 3 while being folded with the bending region 500 as a reference line.

The bending region 500 connects the first region 501 and the second region 502 and may be bent at an angle of 90 degrees to 180 degrees.

The bending region 500, the first region 501, and the second region 502 of the flexible printed circuit board 5 are the bending region 100, the first region 501, and the first region 501 of the flexible printed circuit board 1 of the flexible printed circuit board 1 of FIG.
The region 101 and the second region 102 can correspond to each other.

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

Referring to FIG. 7, the bending area 500 of the flexible printed circuit board has a predetermined radius of curvature r.
It can be attached to the electronic device 3 while holding it.

When the flexible printed circuit board 5 according to the embodiment of the present invention is mounted on the electronic device 3 while being bent, the total thickness D1 of the flexible printed circuit board 5 may be 0.1 mm to 1 mm.

As an example of the flexible printed circuit board according to the embodiment of the present invention, the total thickness D1 of the flexible printed circuit board 5 may be 0.2 mm and the thickness D2 of the cross section may be 0.071 mm. In this case, the radius of curvature r of the bending area of the flexible printed circuit board 5 may be 0.029 mm. The radius of curvature r of the bend region 500 is merely an example, and the radius of curvature of the bend region in the flexible printed circuit board according to some embodiments of the present invention is 0.01 mm to 0.
． It can be 49 mm.

8 to 10 are intermediate stage diagrams illustrating a method of manufacturing a flexible printed circuit board according to an exemplary embodiment of the present invention.

Referring to FIG. 8, a plurality of first wiring patterns 20 are formed on one surface of the base film 10. To form the plurality of first wiring patterns 20, for example, a conductive material is formed on one surface of the base film 10 by a sputtering method or a laminating method, and then a patterning process is performed, or the conductive material is formed on the base film 10. It can be printed on and formed.

Although FIG. 8 shows that the plurality of first wiring patterns 20 are formed only on one surface of the base film 10, the present invention is not limited to this. Like the flexible printed circuit board 2 according to another embodiment of the present invention, the second wiring pattern 120 may be formed on the other surface of the base film 10, which is the opposite surface.

Referring to FIG. 9, the first plating layer 40 may be formed to cover the plurality of first wiring patterns 20.

The first plating layer 40 has a thickness of 0.05 to 0.25 μm and is formed by using a metal material such as tin, nickel, plating, gold, palladium, and aluminum on the first conductive pattern 20 by electrolytic plating or electroless plating. It can be formed to a thickness.

Referring to FIG. 10, the first protective layer 30 may be formed to cover the first plating layer 40 on the bending region 100. The first protective layer 30 can be formed by applying a resist ink, but the present invention is not limited to this, and may be formed by laminating a solder resist or a coverlay film.

Referring to FIG. 3 again, the second plating layer 40 is formed on the first plating layer 40 on which the first protective layer 30 is not formed. The second plating layer 40 may be formed of a metal substance such as tin, nickel, plating, gold, palladium and aluminum by electrolytic plating or electroless plating, similarly to the first plating layer 30. The second plating layer 40 may be formed thicker than the first plating layer 30 in order to secure a sufficient bonding force with the circuit element in the element connection portion 15.

The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to these embodiments and can be manufactured in various forms different from each other. Those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical idea and essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all aspects and not restrictive.

A flexible printed circuit board according to an embodiment of the present invention for achieving the above technical problem is a base film including a bending region, a first region and a second region, and the bending region is the first region. A base film disposed between the second region, a plurality of first wiring patterns formed on one surface of the base film, a first plating layer covering the plurality of first wiring patterns, and the base A first protective layer formed on the bent region of the film so as to cover the first plated layer, and a second plated formed so as to cover the first plated layer on which the first protective layer is not formed. The first plating layer on the bending region is formed to a thickness of 0.05 to 0.25 μm , the second plating layer is thicker than the first plating layer, and the second plating layer is included. the Ru is formed on the upper surface and the side surface of the first plating layer.

In some embodiments of the present invention, a plurality of second wiring patterns formed on the other surface of the base film opposite to the one surface, a third plating layer covering the second wiring pattern, and on the bending region of the base film, wherein a second protective layer formed so as third cover the plating layer, a fourth is formed to cover the third plating layer is not formed in the second protective layer It may further include a plating layer.

A method for manufacturing a flexible printed circuit board according to an embodiment of the present invention for achieving the above technical problem provides a base film including a bending region, a first region, and a second region. A plurality of first wiring patterns are formed on one surface of the base film and are disposed between the first region and the second region, and a first plating layer is formed to cover the plurality of first wiring patterns. A first protective layer is formed on the bent region of the base film so as to cover the first plated layer, and a second plated layer is formed so as to cover the first plated layer on which the first protective layer is not formed. Forming the first plating layer on the bending region to a thickness of 0.05 to 0.25 μm , the second plating layer being thicker than the first plating layer, and the second plating layer being thicker than the first plating layer. plating layer Ru are formed on the upper surface and the side surface of the first plating layer.

An electronic device according to an embodiment of the present invention for achieving the above technical problem includes a first circuit element and a second circuit element; and a first circuit element connected to the first circuit element. A first region extending parallel to the connection surface, a second region connected to the second circuit element and extending parallel to the connection face with the second circuit element, and connecting the first region and the second region, A flexible printed circuit board including a bending region that is bent at an angle of 90 degrees to 180 degrees; the flexible printed circuit board includes a base film, a plurality of wiring patterns formed on at least one surface of the base film, and the plurality of wirings. A first plating layer formed to cover the pattern, a first protective layer formed to cover the first plating layer in the bending region, and the first plating not formed to the first protective layer A second plating layer formed to cover the layer, the first plating layer in the bending region is formed to a thickness of 0.05 to 0.25 μm, and the second plating layer is the first plating layer. thicker than the layer, and the second plating layer is Ru is formed on the upper surface and the side surface of the first plating layer.

Claims (13)

A base film including a bending region, a first region and a second region, wherein the bending region is arranged 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 plurality of first wiring patterns;
A first protective layer formed on the bent region of the base film so as to cover the first plating layer;
A second plating layer formed to cover the first plating layer on which the first protective layer is not formed,
The flexible printed circuit board, wherein the first plating layer on the bent region has a thickness of 0.05 to 0.25 μm. The first wiring pattern includes a device connecting portion,
The flexible printed circuit board according to claim 1, wherein the first protective layer is not formed on the element connecting portion. The flexible printed circuit board according to claim 2, wherein the second plating layer is formed so as to cover the element connecting portion. A plurality of second wiring patterns formed on the other surface of the base film opposite to the one surface,
A third plating layer covering the second wiring pattern,
A second protective layer formed on the bent region of the base film to cover the third plating layer;
The flexible printed board according to claim 1, further comprising a third plating layer formed so as to cover the third plating layer on which the second protective layer is not formed. The flexible printed circuit board of claim 4, wherein the third plating layer is formed to a thickness of 0.05 to 0.25 μm. The flexible printed circuit board according to claim 4, further comprising a via that electrically connects the first wiring pattern and the second wiring pattern inside the base film. The flexible printed board according to claim 1, wherein the second plating layer is formed thicker than the first plating layer. Providing a base film including a bending region, a first region and a second region, the bending region being 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 so as to cover the plurality of first wiring patterns,
Forming a first protective layer on the bent region of the base film so as to cover the first plating layer;
Forming a second plating layer so as to cover the first plating layer on which the first protective layer is not formed,
The method for manufacturing a flexible printed circuit board, wherein the first plating layer on the bent region is formed to a thickness of 0.05 to 0.25 μm. Forming a plurality of second wiring patterns on the other surface of the base film, which is the opposite surface to the one surface,
Forming a third plating layer so as to cover the plurality of second wiring patterns,
Forming a second protective layer on the bent region of the base film so as to cover the third plating layer;
The method of claim 8, further comprising forming a fourth plating layer so as to cover the third plating layer on which the second protective layer is not formed. The method of manufacturing a flexible printed circuit board according to claim 8, wherein forming the second plating layer includes forming the second plating layer to be thicker than the first plating layer. 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 that is connected to the second circuit element and extends parallel to the connection surface with the second circuit element, and connects the first region and the second region, and is bent at an angle of 90 degrees to 180 degrees. A flexible printed circuit board including a bending region;
The flexible printed circuit board,
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 to cover the first plated layer and a second plated layer formed to cover the first plated layer on which the first protective layer is not formed, in the bent region. Including,
The electronic device, wherein the first plating layer in the bending region has a thickness of 0.05 to 0.25 μm. 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 according to claim 11, wherein the electronic device is bent so that The electronic device of claim 11, wherein at least a part of the first area and the second area of the flexible printed circuit board face each other so as to be in contact with each other.