TW201804878A - Flexible printed circuit boards and method for fabricating the same - Google Patents

Abstract

A flexible circuit board and a manufacturing method therefor are provided. A flexible circuit board comprises: a base film; a plurality of first conductive patterns formed on one surface of the base film; a first protection layer formed to cover the plurality of first conductive patterns; and a first heat dissipation layer covering the first protection layer, wherein the first heat dissipation layer includes a base material and a heat dissipation material contained in the base material.

Description

Flexible circuit board and manufacturing method thereof

The invention relates to a flexible circuit board and a manufacturing method thereof.

In recent years, along with the trend of miniaturization of electronic equipment, a chip on film (COF) packaging technology using a flexible circuit board has been increasingly widely used. The COF packaging technology using a flexible circuit board can be applied to a flat panel display device (FPD) such as a liquid crystal display device (LCD), an organic light emitting diode (Organic Light Emitting Diode) display device, and the like.

The conductive patterns formed in the flexible circuit board can connect to each other between circuit elements and transmit electrical signals transmitted at high speed. In addition, with the miniaturization of electronic devices mounted with flexible circuit boards, the flexible circuit boards and the conductive patterns formed in the flexible circuit boards have also shown a trend of high integration, and with the high integration and high precision, the conductive The problem of erroneous operation of circuit elements caused by the heat generated in the pattern has also become increasingly serious.

In order to effectively release the heat generated in the conductive pattern, a method of increasing the heat dissipation characteristic by increasing the thickness of the conductive pattern or by pasting aluminum or copper metal strips on both sides of the base film forming the conductive pattern is currently adopted. However, the method described above may cause problems such as making miniaturization of a flexible circuit board difficult or increasing its production cost due to additional processes.

The technical problem to be solved by the present invention is to provide a flexible circuit board whose heat dissipation characteristics are improved by including a heat dissipation layer containing a heat dissipation material in a protective layer covering a conductive pattern.

Another technical problem to be solved by the present invention is to provide a method for manufacturing a flexible circuit board including a heat dissipation layer containing a heat dissipation material in a protective layer covering a conductive pattern.

The technical subject of the present invention is not limited to the aforementioned technical subject, and relevant practitioners will be able to clearly understand other technical subjects not mentioned by the following description.

In order to achieve the above technical problem, a flexible circuit board to which an embodiment of the present invention is applied includes: a base film; a plurality of first conductive patterns formed on one side of the base film; and a first protective layer covering the plurality of first conductive layers. A pattern; and a first heat-dissipating layer covering the first protective layer, including a base material and a heat-radiating material contained in the base material.

In several embodiments to which the present invention is applied, the height from the base film to the topmost surface of the first protective layer can be equal to or higher than the height from the base film to the topmost surfaces of the plurality of conductive patterns.

In some embodiments to which the present invention is applied, the top surface of the first heat dissipation layer can have a substantially flat structure.

In several embodiments to which the present invention is applied, the thickness ratio of the first protection layer and the first heat dissipation layer can be 2: 8 to 8: 2.

In several embodiments to which the present invention is applied, the thickness of the first protective layer can be 1 to 30 ㎛, the thickness of the first heat dissipating layer can be 1 to 30 ㎛, and the first protective layer and the first heat dissipating The sum of the thicknesses of the layers can be 2 ㎛ to 60 ㎛.

In some embodiments to which the present invention is applied, the substrate may include the same substance as the substance constituting the first protective layer.

In some embodiments to which the present invention is applicable, it may further include: a plurality of second conductive patterns formed on the other side opposite to the one surface of the base film; and a second protective layer covering the plurality of second conductive patterns; And a second heat-dissipating layer covers the second protective layer and includes a heat-dissipating material inside.

In several embodiments to which the present invention is applied, the first protective layer can be formed along the outline of the plurality of first conductive patterns, and the top surface of the first protective layer can include the first surface on the first conductive pattern. The second surface between the first surface and the first surface can have a height from the base film to the first surface higher than a height from the base film to the second surface.

In some embodiments to which the present invention is applied, the first heat dissipation layer can be formed along the contour of the top surface of the first protective layer.

In some embodiments to which the present invention is applicable, it may further include: a gold plating layer interposed between the first conductive pattern and the first protective layer.

In order to achieve the above technical problem, a method for manufacturing a flexible circuit board to which an embodiment of the present invention is applied includes: a step of preparing a base film having a plurality of conductive patterns formed on at least one side thereof; and a step of forming a protective layer covering the plurality of conductive patterns. A step of forming a heat radiating layer including a heat radiating material mixed inside the protective layer.

In several embodiments to which the present invention is applied, the step of forming the heat dissipation layer may further include a step of making a height from the base film to the heat dissipation layer higher than a topmost surface of the conductive pattern.

The flexible circuit board to which the embodiment of the present invention is applied can effectively release the heat generated in the conductive pattern by forming a heat dissipation layer including a heat dissipation material on the base film.

In addition, by completely covering the conductive pattern with the protective layer interposed between the heat dissipation layer and the conductive pattern, it is possible to prevent the problem of the reliability reduction of the electrical appliances caused by the heat dissipation material contained in the heat dissipation layer.

The effects of the present invention are not limited to the above effects, and relevant practitioners will be able to clearly understand other effects not mentioned by the description in the claims.

Through the following embodiments described with reference to the drawings, the advantages and features of the present invention and its implementation method will be further clearly understood. In addition, the present invention is not limited to the embodiments disclosed below, and can also be implemented in a variety of different forms. The following embodiments are only for more complete disclosure of the invention and for those with general knowledge in the technical field to which the invention belongs. The scope of the invention is fully explained, and the invention should be defined by the scope of the claims. In order to facilitate a clearer description, the sizes and relative sizes of the constituent elements in the drawings may be exaggerated. Throughout the specification, the same reference symbols represent the same constituent elements, and "and / or" represents each project mentioned or all combinations of one or more mentioned projects.

Elements or layers are "on" or "on" of other elements or layers, including not only directly above other elements or layers, but also between the two and other layers Or other components. In contrast, an element "directly on" or "directly on" means a case where no other element or layer is included therebetween.

As relative terms in space, "below", "beneath", "lower", "above", "upper", etc. are only used for drawing Correlation between one element or constituent element and other elements or constituent elements illustrated in. Relative terms in space, in addition to the directions illustrated in the drawings, should also be understood to include mutually different directions during use or work. For example, when an element illustrated in a drawing is reversed, an element described as being “below” or “beneath” of another element may be “above” the other element ) ". Therefore, it is possible that "above" as an exemplary term includes both above and below directions. Components can be arranged in different directions, so relative terms in space can also be interpreted in the direction of arrangement.

All terms used in the present specification are only used to describe the embodiments, but not to limit the present invention. Unless otherwise stated in this specification, the singular type includes the plural meaning. The use of "comprises" and / or "comprising" in this specification does not exclude the presence or addition of one or more other constituent elements other than the mentioned constituent elements.

Although terms such as first and second are used to describe different elements or constituent elements, the above-mentioned elements or constituent elements are not limited by the above terms. These terms are only used to distinguish one element or component from other elements or components. Therefore, the first element or component described below may be the second element or component within the scope of the technical idea of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification have the meanings commonly understood by those having general knowledge in the field to which this invention belongs. In addition, unless otherwise stated, terms that have been defined in a dictionary that are generally used should not be interpreted too ideally or exaggeratedly.

FIG. 1 is a cross-sectional view of a flexible circuit board to which an embodiment of the present invention is applied, and FIG. 2 is an enlarged view in which a part of FIG. 1 is enlarged.

As shown in FIGS. 1 and 2, a flexible circuit board to which an embodiment of the present invention is applied can include a base film 10, a first conductive pattern 20, a first protective layer 30, and a first heat dissipation layer 40.

The base film 10 can be made of a flexible material, and as a base material of the flexible circuit board 1, the flexible circuit board 1 can be bent or folded. As the base film 10, for example, a polyimide film can be used. In addition, as the base film 10, for example, a PET film, a polyethylene naphthalate film, a polycarbonate film, or an insulating metal foil can be used. In the flexible circuit board 1 to which an embodiment of the present invention is applied, a case where the base film 10 is a polyimide film will be described as an example.

The first conductive pattern 20 can be formed on the base film 10. The first conductive pattern 20 may have a structure in which at least one strip-shaped conductive wire having a certain width is formed. The first conductive pattern 20 is capable of transmitting electrical signals between a circuit element mounted on the base film 10 and an electronic device in contact with the flexible circuit board 1.

The first conductive pattern 20 can include a conductive material such as copper, but the present invention is not limited thereto. Specifically, the first conductive pattern 20 can be made of a substance having electrical conductivity such as gold or aluminum.

The first protective layer 30 can be formed so as to cover the first conductive pattern 20. The first protective layer 30 can include an insulating substance, and the insulating substance can be, for example, a solder resist. Alternatively, the first protective layer 30 may further include a cover film.

The first protective layer 30 can completely cover the first conductive pattern 20. That is, the horizontal surface of the top surface 35 of the first protective layer 30 can be equal to or higher than the horizontal surface of the top surface 25 of the first conductive pattern 20. That is, the height from the base film 10 to the top surface 35 of the first protective layer 30 can be equal to or higher than the height from the base film 10 to the topmost surface 25 of the first conductive pattern 20.

Although not shown in FIG. 1, a gold plating layer can be additionally formed between the first conductive pattern 20 and the first protective layer 30 to cover the surface of the first conductive pattern 20. The gold plating layer can be formed on the first conductive pattern 20 by gold plating using a substance such as copper, tin, nickel, palladium, gold, or an alloy thereof.

In the flexible circuit board 1 to which an embodiment of the present invention is applied, the top surface 35 of the first protective layer 30 can have a substantially flat structure. Among them, the substantially flat structure may include a case where a certain unevenness is formed on the top surface of the first protective layer 30. However, even if the unevenness as described above is formed, the difference in height between the topmost portion and the bottommost portion of the top surface of the first protective layer 30 is negligible when compared with the entire thickness of the first protective layer 30.

In several embodiments to which the present invention is applied, in order to form the first protective layer 30 having a flat top surface, after the first protective layer 30 is formed on the first conductive pattern 20, the top surface of the first protective layer 30 can be additionally added. A step of performing a flattening process.

A first heat dissipation layer 40 can be formed on the first protective layer 30. The first heat radiation layer 40 can be formed so as to cover the top surface of the first protective layer 30. As shown in FIG. 1, the first heat dissipation layer 40 can be formed so as to completely cover the surface of the first protective layer 30, but the present invention is not limited thereto. The first heat radiation layer 40 may be formed so as to cover only the area of the first protective layer 30 overlapping the first conductive pattern 20.

As described above, the height of the top surface 35 of the first protective layer 30 can be equal to or higher than the height of the top surface 25 of the first conductive pattern 20. Therefore, the bottom surface 41 of the first heat dissipation layer 40 covering the first protective layer 30 The height may be equal to or higher than the height of the topmost surface 25 of the first conductive pattern 20.

In several embodiments to which the present invention is applied, the thickness ratio of the first protective layer 30 and the first heat dissipation layer 40 can be 2: 8 to 8: 2. The thickness of the first protective layer 30 refers to the distance from the top surface of the first conductive pattern 20 to the top surface 35 of the first protective layer 30, and the thickness of the first heat dissipation layer 40 refers to the distance from the first protective layer 30. The distance from the bottom surface 41 of the first heat dissipation layer 40 on the top surface 35 to the topmost surface of the first heat dissipation layer 40. When the thickness of the first heat dissipation layer 40 is too thin compared to the thickness of the first protective layer 30, the heat dissipation effect of the first conductive pattern 20 passing through the first heat dissipation layer 40 may be insufficiently asked. In contrast, if the thickness of the first protective layer 30 is too thin compared to the thickness of the first heat-dissipating layer 40, there may be a problem that the insulation performance is reduced. When the thickness of the first heat-dissipating layer 40 exceeds the thickness of the first protective layer 30 beyond normal requirements, it may cause a problem that the manufacturing cost of the flexible circuit board 1 increases far more than the increase of the heat-dissipating effect.

In several embodiments to which the present invention is applied, the thickness of the first protective layer 30 can be 1 to 30 ㎛, the thickness of the first heat dissipation layer 40 can be 1 to 30 ㎛, and the first protective layer 30 and the first heat radiate The sum of the thicknesses of the layers 40 can be 2 ㎛ to 60 ㎛.

The first heat radiation layer 40 may include a base material and a heat radiation material 45. The substrate can include, for example, a solder resist or a cover film. In several embodiments to which the present invention is applied, the base material of the first heat dissipation layer 40 can include the same material as the first protective layer 30.

The heat-dissipating material 45 included in the first heat-dissipating layer 40 can include a material having a high thermal conductivity, such as a metallic substance such as aluminum or copper, a carbon-containing substance such as graphene, or a carbon nanotube, or a compound thereof.

In several embodiments to which the present invention is applicable, the heat dissipation material 45 can include a spherical heat dissipation ball, but the present invention is not limited thereto. The heat-dissipating material 45 can adopt a polyhedron shape such as a hexahedron. Any material that can mix with the base material of the first heat-dissipating layer 40 and transfer heat generated in the first conductive pattern 20 to the air can be applied regardless of its shape To the present invention.

In the flexible circuit board 1 to which an embodiment of the present invention is applied, the heat dissipation material 45 included in the first heat dissipation layer 40 can be used to cause the heat generated by the first conductive pattern 20 to be released to the outside. Thereby, the first heat dissipation layer 40 can reduce the influence of the heat generated by the first conductive pattern 20 on the circuit elements and the electronic devices mounted in the first conductive pattern 20 and improve the operational reliability of the flexible circuit board 1.

In addition, the method of forming the first heat dissipation layer 40 on the first protective layer 30 as described above has advantages over the method of forming separate metal strips on both sides of the base film 10 in terms of production process and production cost.

In addition, in the flexible circuit board 1 to which an embodiment of the present invention is applied, the first heat dissipation layer 40 can be separated from the first conductive pattern 20 by the first protective layer 30. Moreover, since the height of the top surface 35 of the first protective layer 30 is equal to or higher than the height of the topmost surface of the first conductive pattern 25, there is no first heat dissipation layer 40 between the plurality of conductive patterns 20 and included in the first A heat radiating material 45 in the heat radiating layer 40 is present.

If the first heat-dissipating layer 40 containing the heat-dissipating material 45 exists between the first conductive patterns 20 of the base film 10, it may flow between the first conductive patterns 20 due to the reaction of the heat-dissipating material 45 and moisture or the like. The leakage current of the first conductive pattern 20 is reduced due to the leakage current. Furthermore, it may cause a reduction in the operational reliability of the flexible circuit board.

However, the first heat dissipation layer 40 of the flexible circuit board 1 to which an embodiment of the present invention is applied does not include the first heat dissipation layer 40 and the heat dissipation material 45 included in the first heat dissipation layer 40 between the plurality of first conductive patterns 20. Existence, even if the heat radiating material 45 in the first heat radiating layer 40 reacts with moisture, it is possible to prevent a leakage current from being formed between the first conductive patterns 20 and thereby effectively form insulation between the first conductive patterns 20.

3 is a cross-sectional view of a flexible circuit board to which another embodiment of the present invention is applied. The same parts as the above-mentioned embodiments will omit their detailed description and highlight the differences between the two.

As shown in FIG. 3, the flexible circuit board 2 to which another embodiment of the present invention is applied has a different shape from the first protective layer 130 and the first heat dissipation layer 140 compared to the flexible circuit board to which the above embodiment is applied.

The top surface 135 of the first protective layer 130 is formed along the contour of the top surface of the first conductive pattern 20. That is, the top surface 135 of the first protective layer 130 includes the second surface 137 between the first surface 136 and the first surface 136 on the first conductive pattern 20, and the height from the base film 10 to the first surface 136 is higher than The height of the second surface 137.

In addition, although the top surface 135 of the first protective layer 130 is formed along the contour of the top surface of the first conductive pattern 20, it can still be equal to or higher than the height of the topmost surface of the first conductive pattern 20. That is, the horizontal surface of the second surface 137 of the top surface 135 of the first protective layer 130 which is lower than the height of the first surface 136 is still equal to or higher than the horizontal surface of the top surface of the first conductive pattern 20, thereby preventing the first conductive pattern from being formed. The first heat dissipation layer 140 and the heat dissipation material included in the first heat dissipation layer 14 exist between 20. Thereby, regardless of the shape of the top surface 135 of the deformed first protective layer 130, the insulating effect between the first conductive patterns 20 can be maintained by the first protective layer 130 and the first heat dissipation layer 140.

By forming the first protective layer 130 along the contour of the top surface of the first conductive pattern 20, the shape of the first heat dissipation layer 140 covering the first protective layer 130 can also be formed along the contour of the first protective layer 130. Thereby, the top surface of the first heat dissipation layer 140 can include the first surface 141 and the second surface 142 between the first surface on the first conductive pattern 20, and the height of the first surface 141 can be higher than that of the second surface 142. the height of.

In addition, as in the case of the above embodiment, the height of the bottom surface of the first heat dissipation layer 140 can be equal to or higher than the height of the topmost surface of the first conductive pattern 20.

In the flexible circuit board 2 to which this embodiment is applied, the first protective layer 130 is formed along the contour of the surface of the first conductive pattern 20, so the shape of the top surface 135 of the curved first protective layer 130 may cause the first protective layer. The top surface 135 of 135 has an increased surface area. In addition, as the surface area of the top surface 135 of the first protective layer 130 increases, the contact area between the first protective layer 130 and the first heat dissipation layer 140 also increases. Thereby, the heat conduction efficiency of the first conductive pattern 20 transmitted to the first heat dissipation layer 140 through the first protective layer 130 can be improved.

In addition, when the first protective layer 130 is formed along the outline of the first conductive pattern 20, it is not necessary to perform a step of planarizing the top surface of the first protective layer 130 after the first protective layer 130 is formed.

4 is a cross-sectional view of a flexible circuit board to which another embodiment of the present invention is applied.

As shown in FIG. 4, the flexible circuit board 3 to which another embodiment of the present invention is applied may further include a plurality of second conductive patterns 120 formed on the opposite side of the first conductive pattern 20 of the base film 10; the second The protective layer 230, the second heat radiation layer 240, and a conductive member 51 penetrating the base film 10.

The second conductive pattern 120 can be formed on the other surface opposite to the surface on which the first conductive pattern 20 is formed in the base film 10. The second conductive pattern 120 is the same as the first conductive pattern 20 and can include at least one strip-shaped wire having a certain width.

The second conductive pattern 120 can be connected to the first conductive substrate 20 through a conductive material 51 penetrating the substrate. The via 51 can fill a via 50 formed through the base film 10. The conductive material 51 is the same as the first and second conductive patterns 120 and can include a conductive material such as copper or gold or an alloy thereof. Although not shown in FIG. 4, more than one metal layer can be additionally included between the inner sidewall of the via 50 and the via 51.

FIG. 4 illustrates the case where the first conductive pattern 20 and the second conductive pattern 120 are formed at corresponding positions centered on the base film 10, but the present invention is not limited thereto. Persons having general knowledge in the technical field to which the present invention pertains should understand that the configuration of the first and second conductive patterns 120 will be different according to the design of the flexible circuit board 1 and the configuration of the circuit elements mounted thereon.

The second protective layer 230 can be formed so as to cover the second conductive pattern 120. Similar to the first protective layer 30, the second protective layer 230 can completely cover the second conductive pattern 120. Therefore, the height from the other surface of the base film 10 to the top surface of the second protective layer 230 can be equal to or higher than the height of the topmost surface of the second conductive pattern 120.

A second heat dissipation layer 240 can be formed on the second protective layer 230. The second heat radiating layer 240 can include a base material as an insulating material and a heat radiating material contained in the base material. The first heat radiation layer 40 and the second heat radiation layer 240 may include the same substance. That is, the base material and the heat radiation layer constituting the first heat radiation layer 40 and the second heat radiation layer 240 can include the same substance.

As shown in FIG. 4, the second heat-dissipating layer 240 can be formed so as to completely cover the second protective layer 230, and the second heat-dissipating layer 240 can also cover the second protective layer 230 only on the area where the second conductive pattern 40 is formed. The top surface is formed.

The principle that the top surface of the second protective layer 230 is equal to or higher than the horizontal surface of the top surface of the second conductive pattern 120 prevents the second heat dissipation layer 240 from being formed between the second conductive pattern 120 and the first heat dissipation layer. 40 The related description is the same. As a result, the shape of the second heat-dissipating layer 240 as described above helps to release the heat generated by the second conductive coating layer 120 to the air, and also prevents the heat from being generated between the second conductive pattern 120 and the heat-dissipating material. A problem that a leakage current is generated to reduce the operational reliability of the flexible circuit board 3.

FIG. 5 is a sequence diagram of a method for manufacturing a flexible circuit board according to an embodiment of the present invention.

As shown in FIG. 5 and FIG. 1, a method for manufacturing a flexible circuit board to which an embodiment of the present invention is applied, includes: S10, a step of preparing a base film having a plurality of conductive patterns formed on at least one side thereof; Step of the first protective layer of each conductive pattern; S30, a step of forming a heat radiating layer including a heat radiating material on the first protective layer.

The first conductive pattern 20 can be formed by a semi additive process such as forming a resist layer on the base film 10 by electrolytic or non-electrolytic gold plating, or by forming a conductive layer on the base film 10 Then, an etching process is performed on the conductive layer.

The step of forming the first protective layer 30 covering the plurality of first conductive patterns 20 may include a step of printing or laminating a solder resist or a cover film on the first conductive patterns 20. In order to make the horizontal surface of the top surface of the first protective layer 30 higher than the horizontal surface of the top surface of the first conductive pattern 20, it is necessary to form a sufficient first protective layer 30.

Among them, in order to keep the horizontal surface of the top surface of the first protective layer 30 substantially flat, a process of planarizing the top surface can be additionally performed after the first protective layer 30 is formed. The process of planarizing the top surface of the first protective layer 30 can include, for example, a step of pressing the top surface of the first protective layer 30 using a punch.

The step of forming the first heat dissipation layer 40 covering the first protection layer 30 may include a step of printing or laminating a solder resist or a cover film including the heat dissipation material 45 onto the first protection layer 30.

The embodiments to which the present invention is applied have been described above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and can also be manufactured in many different forms. Persons with general knowledge in the field to which the present invention belongs will understand that When the technical idea and necessary features of the present invention are changed, the present invention can be implemented in a variety of different specific forms. Therefore, the embodiments described above are for illustrative purposes only in all respects and not a limitation on the present invention.

1,2,3‧‧‧‧flexible circuit board

10‧‧‧ base film

20, 120‧‧‧ conductive pattern

30, 130, 230‧‧‧ protective layer

40, 140‧‧‧ heat dissipation layer

45‧‧‧ Thermal Material

FIG. 1 is a cross-sectional view of a flexible circuit board to which an embodiment of the present invention is applied.

FIG. 2 is an enlarged view enlarging a part of FIG. 1.

3 is a cross-sectional view of a flexible circuit board to which another embodiment of the present invention is applied.

4 is a cross-sectional view of a flexible circuit board to which another embodiment of the present invention is applied.

FIG. 5 is a sequence diagram of a method for manufacturing a flexible circuit board according to an embodiment of the present invention.

1,2,3‧‧‧‧flexible circuit board

10‧‧‧ base film

20, 120‧‧‧ conductive pattern

30, 130, 230‧‧‧ protective layer

40, 140‧‧‧ heat dissipation layer

45‧‧‧ Thermal Material

Claims (12)

A flexible circuit board, comprising: a base film; a plurality of first conductive patterns formed on one side of the base film; a first protective layer covering the plurality of first conductive patterns; and a first heat dissipation layer covering The first protective layer includes a substrate and a heat dissipation material contained in the substrate. The flexible circuit board according to claim 1, wherein a height from the base film to a topmost surface of the first protective layer is equal to or higher than a height from the base film to a topmost surface of the plurality of conductive patterns. height. The flexible circuit board according to claim 1, wherein a top surface of the first heat dissipation layer has a substantially flat structure. The flexible circuit board according to claim 1, wherein a thickness ratio of the first protective layer and the first heat dissipation layer is 2: 8 to 8: 2. The flexible circuit board according to claim 1, wherein the thickness of the first protective layer is 1 to 30 ㎛, the thickness of the first heat dissipation layer is 1 to 30 ㎛, and the first protective layer and the 1 The sum of the thickness of the heat dissipation layer is 2㎛ to 60㎛. The flexible circuit board according to claim 1, wherein the base material includes the same material as that constituting the first protective layer. The flexible circuit board according to claim 1, further comprising: a plurality of second conductive patterns formed on the other surface opposite to the one surface of the base film; and a second protective layer covering the plurality of second conductive patterns. A conductive pattern; and a second heat-dissipating layer covering the second protective layer and including a heat-dissipating material inside. The flexible circuit board according to claim 1, wherein the first protective layer is formed along an outline of the plurality of first conductive patterns, and a top surface of the first protective layer includes the first conductive pattern on the first conductive pattern. The second surface between the first surface and the first surface has a height from the base film to the first surface that is higher than a height from the base film to the second surface. The flexible circuit board according to claim 8, wherein the first heat dissipation layer is formed along a contour of a top surface of the first protective layer. The flexible circuit board according to claim 1, further comprising: a gold plating layer interposed between the first conductive pattern and the first protective layer. A method for manufacturing a flexible circuit board, comprising: a step of preparing a base film having a plurality of conductive patterns formed on at least one side thereof; a step of forming a protective layer covering a plurality of conductive patterns; and forming a protective layer on the protective layer including mixing A step of dissipating a heat-dissipating layer inside it; wherein a height from the base film to the first protective layer is higher than a height from the base film to a topmost surface of the plurality of conductive patterns. The method for manufacturing a flexible circuit board according to claim 11, wherein the step of forming a heat dissipation layer further comprises a step of making a height from the base film to the heat dissipation layer higher than a topmost surface of the conductive pattern. .