JP7607693B2 - Flexible Circuit Board - Google Patents

Description

The present invention relates to a flexible circuit board having via pads.

Recently, with the trend toward miniaturization of electronic devices, chip-on-film (COF) packaging technology using flexible circuit boards has come to be used. Flexible circuit boards and COF packaging technology using the same are used in flat panel displays (FPDs) such as liquid crystal displays (LCDs) and organic light emitting diode (OLED) display devices.

As electronic products become smaller and more complex, the complexity of the wiring on flexible circuit boards has increased. To increase the density of the wiring on a flexible circuit board, a structure is used in which wiring is placed on both sides of the flexible circuit board and connected through via holes.

Due to the density of the fine wiring pattern, there is a somewhat small positional margin when forming the via pads so that they overlap with the via holes formed in the base film.

The problem that this invention aims to solve is to provide a flexible circuit board including a via pad that can ensure sufficient positional margin for the via hole against deformation of the base film.

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

A flexible substrate circuit according to one embodiment of the present invention for achieving the above technical objective includes a base film, a first wiring pattern extending in a first direction on one surface of the base film, a first via pad connected to the first wiring pattern at a connection region and having a polygonal shape, and a first via hole passing through the base film and overlapping with the first via pad, the first via pad having a width in a second direction perpendicular to the first direction and a width in the second direction decreasing toward the first direction in a central region, the first via pad having a first side and a second side contacting the first wiring pattern at the connection region, a third side extending substantially parallel to the first side, and a front side extending substantially parallel to the front side. and a fourth side extending substantially parallel to the second side, the first side and the fourth side meet at a first vertex, the distance between the first via hole and the first vertex is greater than the distance between the first via hole and the first side, the flexible circuit board further has a third wiring pattern, a second via pad is connected to the third wiring pattern, the first wiring pattern and the third wiring pattern extend in the same direction and are respectively connected to the first via pad and the second via pad, and the first via pad and the second via pad are arranged to form an acute angle with the first wiring pattern and the third wiring pattern.

In some embodiments of the present invention, the second side and the third side may meet at a second vertex.

In some embodiments of the present invention, the first via pad may further include a fifth side, and at least one pair of the first to fourth sides may be connected via the fifth side.

In some embodiments of the present invention, the first side may be spaced a first distance from the center of the first via pad, and the fifth side may be spaced a second distance from the center of the first via pad, and the second distance may be greater than the first distance.

In some embodiments of the present invention, the first via pad may further include an arc connecting at least a pair of the first to fourth sides.

In some embodiments of the present invention, the first side may be spaced a first distance from the center of the first via pad, and the radius of curvature of the arc may be smaller than the first distance.

In some embodiments of the present invention, the device may further include a second wiring pattern formed on the other side of the base film opposite the one side, and the first wiring pattern and the second wiring pattern may be electrically connected through the first via pad.

A flexible printed circuit according to another embodiment of the present invention for achieving the above technical objective includes a base film, a first wiring pattern extending in a first direction on one surface of the base film, a via pad having a polygonal shape and at least a portion of which is connected to the first wiring pattern, and a via hole that penetrates the base film and overlaps with the via pad, the via pad includes a first side and a second side that form an acute angle with the first direction and extend parallel to each other, and a third side that extends perpendicular to the extension direction of the first side and the second side, the second side and the third side meet at a second vertex, the distance between the via hole and the second vertex is greater than the distance between the via hole and the third side, the first side and the second side extend from the first wiring pattern, and the length of the second side is greater than the length of the first side.

In some embodiments of the present invention, the via pad may further include a fifth side, and at least one pair of the first to third sides may be connected via the fifth side.

In some embodiments of the present invention, the third side and the center of the via pad are spaced apart by a first distance, and the fifth side and the center of the via pad are spaced apart by a second distance, and the first distance may be smaller than the second distance.

In some embodiments of the present invention, the via pad may further include an arc connecting at least a pair of the first to third sides.

In some embodiments of the present invention, the radius of curvature of the arc may be less than the separation distance between the first edge and the center of the via pad.

In some embodiments of the present invention, the via pad may include a width in a second direction perpendicular to the first direction, and the width in the second direction may decrease in a central region toward the first direction.

Specific details of other embodiments are included in the detailed description and drawings.

The flexible circuit board according to an embodiment of the present invention allows the via holes to be aligned with a positional margin within the via pad even when the base film has a vertical or horizontal orientation and is deformed due to an external factor.

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

FIG. 1 is a plan view of a flexible circuit board according to one embodiment of the present invention. This is a cross-sectional view taken along line A-A' in Figure 1. 2 is a plan view showing a via pad included in a flexible circuit board according to an embodiment of the present invention; 1 is an exemplary diagram illustrating a position margin of a via hole relative to a via pad in a flexible circuit board according to some embodiments of the present invention. 1 is an exemplary diagram illustrating a position margin of a via hole and a via pad of a flexible circuit board according to the prior art; 11A to 11C are plan views showing modified examples of via pads included in flexible circuit boards according to some embodiments of the present invention. 11A to 11C are plan views showing modified examples of via pads included in flexible circuit boards according to some embodiments of the present invention. 11A to 11C are plan views showing modified examples of via pads included in flexible circuit boards according to some embodiments of the present invention. 11A to 11C are plan views showing modified examples of via pads included in flexible circuit boards according to some embodiments of the present invention. 11A to 11C are plan views showing modified examples of via pads included in flexible circuit boards according to some embodiments of the present invention.

Advantages and features of the present invention, as well as methods for achieving the same, will become clear from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms, and the embodiments are provided merely to complete the disclosure of the present invention and to fully inform those skilled in the art of the invention of the scope of the invention, and the present invention is defined only by the scope of the claims. Sizes and relative sizes of components shown in the drawings may be exaggerated for clarity. The same reference numerals refer to the same components throughout the specification, and "and/or" includes each and every combination of one or more of the referenced items.

When an element or layer is said to be "on" another element or layer, this includes not only directly on top of the other element or layer, but also cases where there are other layers or elements in between. Conversely, when an element is said to be "directly on" or "directly above" it means that there are no other elements or layers in between.

Spatially relative terms such as "below," "beneath," "lower," "above," and "upper" are used to facilitate describing the relationship of one element or component to another element or component as shown in the drawings. Spatially relative terms should be understood to include different orientations of elements in use or operation in addition to the orientation shown in the drawings. For example, if an element shown in the drawings is upside down, an element described as "below" or "beneath" another element may be "above" the other element. Thus, the exemplary term "below" includes both an orientation of below and above. Elements may be oriented in other directions, and thus the spatially relative terms may be interpreted accordingly.

The terms used in this specification are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular form includes the plural form unless otherwise specified in the text. The words "comprises" and/or "comprising" used in the specification do not exclude the presence or addition of one or more other components in addition to the components mentioned.

Although the terms "first", "second", etc. are used to describe various elements or components, it is of course not intended that these elements or components be limited by these terms. These terms are used merely to distinguish one element or component from another element or component. Therefore, it is of course possible for a first element or component referred to below to be a second element or component within the technical concept of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification are used as commonly understood by those having ordinary knowledge in the technical field to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless clearly defined otherwise.

Figure 1 is a top view showing a flexible circuit board according to an embodiment of the present invention, and Figure 2 is a cross-sectional view taken along line A-A' in Figure 1.

Referring to Figures 1 and 2, a flexible circuit board 1 according to an embodiment of the present invention may include a base film 10, a first wiring pattern 20, a second wiring pattern 50, a via pad 30 and a via hole 40.

The base film 10 is made of a flexible material and is included in the flexible circuit board 1 as a substrate, allowing the flexible circuit board 1 to be bent or folded. The base film 10 may be, for example, a polyimide film, but the present invention is not limited thereto. Alternatively, the base film 10 may be a PET film, a polyethylene naphthalate film, a polycarbonate film, or an insulating metal foil. In the electronic device 1 according to one embodiment of the present invention, the base film 10 is a polyimide film.

The first wiring pattern 10 may extend in a first direction D1 on one surface of the base film 10. In this specification, the first direction D1 refers to the length direction of the flexible circuit board 1, i.e., the vertical direction in FIG. 1. Meanwhile, the second direction D2 refers to the width direction of the flexible circuit board 10, i.e., the horizontal direction in FIG. 1, and the first direction D1 and the second direction D2 are perpendicular to each other. The second wiring pattern 50 may be formed on the other surface of the base film 10. That is, the first wiring pattern 20 and the second wiring pattern 50 are respectively formed on opposing surfaces of the base film 10.

The first wiring pattern 20 and the second wiring pattern 50 may include a conductive material such as copper, but the present invention is not limited thereto. Specifically, the first wiring pattern 20 and the second wiring pattern 50 are made of an electrically conductive material such as gold or aluminum.

Although not shown in FIG. 1 and FIG. 2, one or more insulating layers may be formed to cover the first wiring pattern 20 and the second wiring pattern 50. The one or more insulating layers may include, for example, a solder resist, and can protect the first wiring pattern 20 or the second wiring pattern 50 from external factors.

The via pad 30 is arranged to electrically connect the first wiring pattern 20 and the second wiring pattern 50. That is, a via hole 40 is formed so as to penetrate the base film 10, and the via pad 30 fills the via hole 40, and is connected to the first wiring pattern 20 formed on one side of the base film 10 and the second wiring pattern 50 on the other side, respectively, and can electrically connect them.

The via pad 30 may include an electrically conductive material such as copper, gold, or an alloy thereof, similar to the first wiring pattern 20 or the second wiring pattern 50. FIG. 3 is a plan view showing a via pad included in a flexible circuit board according to an embodiment of the present invention. The shape of the via pad 30 will be described in more detail below with reference to FIG. 3. The via pad 30 may include first to fourth sides (31, 32, 33, 34) that are arranged to overlap the via hole 40 and surround the via hole 40. The first side 31 and the fourth side 34 meet at a first vertex 41, the second side 32 and the third side 33 meet at a second vertex 42, and the third side 33 and the fourth side 34 meet at a third vertex 53.

Meanwhile, the first side 31 and the second side 32 of the via pad 30 contact the first wiring pattern 20 in the connection region 21. That is, the first side 31 and the second side 32 may extend from the connection region 21 at an acute angle with the first direction D1 in which the first wiring pattern 20 extends.

Here, the angle "a specific direction different from a specific direction forms a specific angle" refers to the smaller of the two angles formed by the intersection of the two directions. For example, if the angles formed by the intersection of the two directions are 114° and 60°, it means 60°. Therefore, as shown in FIG. 3, the angle formed by the first direction D1 and the first side 31 is a1, and the angle formed by the first direction D1 and the second side 32 is a2.

As shown in FIG. 3, the connection region 21 is located at the vertex where the first side 31 and the second side 32 meet. Meanwhile, in another embodiment of the present invention, when the first wiring pattern 20 and the via pad 30 are connected on one of the first to fourth sides 31 to 34, the connection region 21 may be located on the first to fourth sides 31 to 34.

In some embodiments of the present invention, the angle between the extension directions of the first side 31 and the second side 32 may be approximately 90°. In some embodiments of the present invention, the angles between the first side 31 and the second side 31, 32 and the first direction D1 may be the same, at approximately 45°.

Furthermore, the first side 31 and the third side 33 may extend substantially parallel, and the second side 32 and the fourth side 34 may extend substantially parallel.

Here, "substantially parallel" does not only mean that the first side 31 and the third side 33, or the second side 32 and the fourth side 34, are physically parallel, but can also include cases where there is some difference depending on the margin or yield of the via pad 30 formation process.

The via pad 30 is connected to the first wiring pattern 20 through a connection region 21 on one surface of the base film 10. The via pad 30 has a width in the second direction D2, and the width of the via pad 30 in the second direction D2 decreases from the connection region 21 toward the first direction D1.

That is, the via pad 30 has a first width W1 in the second direction D2 at a point where a virtual line extending from the connecting region 21 in the second direction D2 meets the third vertex 53, and the first width W1 is maximum. In contrast, a second width W2 at an arbitrary point where the virtual line extending in the second direction D2 meets the second side 32 and the third side 33, and a third width W3 at an arbitrary point where the virtual line extending in the second direction D2 meets the first side 31 and the fourth side 34 are smaller than the width W1.

The area on the via pad 30 occupied by an imaginary line extending from the third vertex 53 in the second direction D2 is defined as the "central region," and the via pad 30 can be described as having a width that decreases in the second direction D2 as it moves from the "central region" in the first direction D1.
Each side (31 to 34) of the via pad 30 is spaced from the via hole 40 by a first distance K. The shape of the via pad 30 and the position of the via hole 40 will be described with reference to the following Figures 4A and 4B.

Figure 4A is an exemplary diagram illustrating the position margin of a via hole relative to a via pad in a flexible circuit board according to some embodiments of the present invention, and Figure 4B is an exemplary diagram illustrating the position margin between a via hole and a via pad in a flexible circuit board according to the prior art.

Referring to Figures 3 and 4A, in some embodiments of the present invention, when the center of gravity of the via pad 30 and the center of gravity of the via hole 40 are the same, the shortest distance between each side (31-34) of the via pad 30 and the via hole 40 is the first distance K.

Meanwhile, in the process of forming the via hole 40 and the via pad 30, the centers of gravity of the via hole 40 and the via pad 30 may not coincide with each other, and an error of the second distance K1 may occur in the first direction D1 as shown in FIG. 4a, resulting in the placement of the via hole 40 and the via pad 30. In this case, the shortest distance between the first side 31 of the via pad 30 and the via hole 40 is the third distance K2.

In FIG. 4B, the via pad 60 included in the flexible circuit board according to the prior art has a shape in which the width of the wiring pattern 20 is expanded in the second direction D2. As in FIG. 4A, if the centers of gravity of the via hole 40 and the via pad 60 do not coincide with each other and an error of the second distance K1 occurs, the shortest distance between the via hole 40 and the side 62 of the via pad 60 may be separated by a fourth distance K3.

Here, the shortest distance K2 between the via pad 30 and the via hole 40 in FIG. 4A can be calculated as follows:

Next, the shortest distance K3 between the via pad 60 and the via hole 40 in FIG. 4B can be calculated as follows:

In the flexible circuit board 1 according to the embodiment of the present invention, the first side 31 and the second side 32 of the via pad 30 form an acute angle with the first wiring pattern 20 (0<cos a ₁ <1), so that the relational expression K2>K3 holds.

In a flexible circuit board according to an embodiment of the present invention, a via hole 40 is formed through the base film 10, and the via hole 40 is filled with a conductive material to form a via pad 30. At this time, the position of the via hole 40 is designed so that it overlaps with the via pad 30 and the centers of gravity of the via hole 40 and the via pad 30 are aligned to ensure the maximum positional margin.

However, due to environmental factors applied to the base film 10, such as the contraction or expansion of the base film 10 due to heat treatment, the positions of the pre-formed via hole 40 and the via pad 30 may shift, resulting in the via pad 30 being formed so that the via hole 40 is biased to one side of the via pad 30. If an error occurs in the alignment to the extent that the via pad 30 and the via hole 40 do not overlap, poor conductivity may occur between the first wiring pattern and the second wiring pattern (20, 50 in FIG. 1), which may cause product defects. Therefore, it is important to ensure the maximum positional margin for the relative movement of the via hole 40 with respect to the via pad 30.

On the other hand, the deformation of the base film 10 during the manufacturing process of the flexible circuit board 1 may have a certain directionality. That is, the directionality of the contraction or expansion of the base film 10 is predominantly in the first direction D1 or the second direction D2. Here, the fact that the directionality of the deformation of the base film 10 is predominantly in the first direction D1 means that the first direction D1 component is the majority of the vector components of the relative movement direction of the via hole 40 with respect to the via pad 30 due to the deformation of the base film 10.

In this way, when the directionality of the relative movement of the via hole 40 with respect to the via pad 30 of the flexible circuit board 1 is predominantly in the first direction D1 or the second direction D2, it is advantageous to ensure a positional margin for the first side 31 and the second side 32 of the via pad 30 to form an acute angle with the first direction D1.

Different from the arrangement of the via pad 30 and the first wiring pattern 20 described above, the first wiring pattern 20 may be arranged to be connected to any one of the first to third vertices (41, 42, 53) of the via pad 30. That is, the first wiring pattern 20 may extend in the first direction D1 and be connected to the via pad 30 through the third vertex 53, or extend in the second direction D2 and be connected to the via pad 30 through the first vertex or the second vertex 41, 42. In addition, the first wiring pattern 20 may be arranged to be connected to a predetermined position of any one of the first to fourth sides 31 to 34 of the via pad 30.

Figure 5 is a top view of a via pad included in a flexible circuit board according to another embodiment of the present invention.

Referring to FIG. 5, the via pad 130 may further include a fifth side 35 interposed between the first side 31 and the fourth side 34, and a sixth side 36 interposed between the second side 32 and the third side 33. In addition, a seventh side 37 may be interposed between the third side 33 and the fourth side 34, connecting the third side 33 and the fourth side 34.

The via pad 130 has a maximum width W4 at the point where the seventh side 37 meets an imaginary line extending from the connecting region 21 in the second direction D2. As described above, the via pad 130 has widths W2 and W3 in the second direction D2 that are smaller than the maximum width W4 as it approaches the first direction D1.

In some embodiments of the present invention, the distance D1 between the via hole 40 and the fifth side 35 or the distance D2 between the via hole 40 and the sixth side 36 is greater than the shortest distance K between the via hole 40 and the first side 31. That is, the distance D1 between the via hole 40 and the fifth side 35 is greater than the first distance K between the via hole 40 and the first side 31. This is because if the distance D1 between the via hole 40 and the fifth side 35 is smaller than or equal to the first distance K between the via hole 40 and the first side 31, the positional margin for the movement of the via hole 40 in the first direction D1 becomes even smaller.

This also applies to the separation distance between the via hole 40 and the sixth side 36, or the via hole 40 and the seventh side 37, all of which are greater than the separation distance K between the via hole 40 and the first side 31.

Meanwhile, in some embodiments of the present invention, the via pad 130 may not include at least one of the fifth to seventh sides 35-37. That is, any pair of adjacent sides among the first to fourth sides 31-34 may be connected via any one of the fifth to seventh sides 35-37, and the remaining sides may be directly connected.

Figure 6 is a top view of a via pad included in a flexible circuit board according to another embodiment of the present invention.

Referring to FIG. 6, the via pad 230 may include a first arc 43 connecting the first side 31 and the fourth side 34, a second arc 44 connecting the second side 32 and the third side 33, and a third arc 45 connecting the third side 33 and the fourth side 34. That is, in comparison with the via pad 130 described above with reference to FIG. 5, the first to third arcs (43, 44, 45) may be arranged with rounding processing to connect the first to fourth sides 31 to 34.

The first through third arcs 43-45 may have a radius of curvature R. In some embodiments of the present invention, the radius of curvature R of the first through third arcs 43-45 may be smaller than the distance K4 between the center of the via hole 40 and the first side 31. This is because if the radius of curvature R of the first through third arcs 43-45 is greater than or equal to the distance K4, the via pad 230 will be formed in an elliptical shape and there will be little positional margin.

Meanwhile, in some embodiments of the present invention, the via pad 230 may not include any one of the first to third arcs 43 to 45. That is, any pair of adjacent sides among the first to fourth sides 31 to 34 may be connected via any one of the first to third arcs 43 to 45, and the remaining sides may be directly connected.

Figure 7 is a top view of a via pad included in a flexible circuit board according to another embodiment of the present invention.

Referring to FIG. 7, the via pad 330 may include a first wiring pattern 20 extending in a first direction D1, a first side 131 and a second side 132 extending at an acute angle, and a third side 33 extending perpendicular to the direction in which the first side 131 and the second side 132 intersect with the first direction D1.

The first side 131 and the second side 132 form an acute angle with the first wiring pattern 20 and extend parallel to each other. That is, the angle a1 that the first side 131 makes with the first direction D1 is the same as the angle a2 that the second side 132 makes with the first direction D1.

The first side 131 and the third side 133 may be in contact with each other at a first vertex 141, and the second side 132 and the third side 133 may be in contact with each other at a second vertex 142. That is, the first side 131 and the second side 132 may be connected to each other via the third side 133.

The via pad 330 may have a maximum width W1 in the second direction D2 based on the second vertex 142. That is, the via pad 330 has a maximum width W1 at the point where the imaginary line extending in the second direction D2 at the second vertex 142 meets the first wiring pattern 20.

Therefore, since the width of the via pad 330 in the second direction D2 decreases as one moves in the first direction D1 from the second vertex 142, the second width W2 at any point where the imaginary line extending in the second direction D2 meets the first side 131 and the third side 133, and the third width W3 at any point where the imaginary line extending in the second direction D2 meets the second side 132 are smaller than the width W1. As described above, the area of the via pad 330 occupied by the imaginary line extending from the second vertex 142 in the second direction D2 is defined as the "center area", and the via pad 330 can be described as having a width in the second direction D2 that decreases as one moves from the "center area" in the first direction D1.

The via hole 140 is spaced apart from the third side 133 by a first distance K. The via hole 140 is also spaced apart from the first side 131 and the second side 132 by a first distance K. The via hole 140 is surrounded by the first wiring pattern 120 and the first to third sides (131, 132, 133).

Figure 8 is a top view of a via pad included in a flexible circuit board according to another embodiment of the present invention.

Referring to FIG. 8, the via pad 430 may further include a fourth side 135 that connects the first side 131 and the third side 133, and a fifth side 136 that is interposed between the second side 132 and the third side 133. That is, the via hole 140 is surrounded by the first wiring pattern 20 and the first to fifth sides (131, 132, 133, 135, 136).

The fourth side 135 may extend in the second direction D2, and the fifth side 136 may extend in the first direction.

The via pad 430 has a maximum width W4 at the point where the fifth side 136 meets an imaginary line that passes through the center of gravity of the via hole 140 and extends in the second direction D2. As described above, the via pad 430 has widths W2 and W3 in the second direction D2 that are smaller than the maximum width W4 as it approaches the first direction D1.

In some embodiments of the present invention, the distance D1 between the via hole 140 and the fifth side 136 is greater than the shortest distance K between the via hole 140 and the third side 133. That is, the distance D1 between the via hole 140 and the fifth side 136 is greater than the first distance K between the via hole 140 and the third side 133.

This also applies to the distance between the via hole 140 and the fourth side 135, so that the distance between the via hole 140 and the fourth side 135 is greater than the distance K between the via hole 140 and the third side 133 or the first side 131.

Meanwhile, in some embodiments of the present invention, the via pad 430 may not include any one of the first or second sides 135, 136. That is, any pair of adjacent sides among the first to third sides 131-133 may be connected via any one of the first or second sides 135, 136, and the remaining sides may be directly connected.

Figure 9 is a top view of a via pad included in a flexible circuit board according to another embodiment of the present invention.

Referring to FIG. 9, the via pad 530 may include a first arc 144 connecting the first side 131 and the third side 133, and a second arc 145 connecting the second side 132 and the third side 133. In other words, compared to the via pad 130 described with reference to FIG. 8, the first and second arcs 144 and 145 are arranged with rounding processing to connect the first to third sides 131 to 33.

The first and second arcs 144, 145 have a radius of curvature R. In some embodiments of the present invention, the radius of curvature R of the first and second arcs 144, 145 may be less than the distance K that the center of the via hole 140 is spaced from the no. 3133.

Meanwhile, in some embodiments of the present invention, the via pad 530 may not include any one of the first or second arcs 144, 145. That is, any pair of adjacent sides among the first to third sides 131-133 may be connected via any one of the sides 144, 145 of the first or second arc, and the remaining sides may be directly connected.

Although the embodiments of the present invention have been described above with reference to the attached drawings, the present invention is not limited to the above embodiments and can be manufactured in various different forms, and a person having ordinary knowledge in the technical field to which the present invention belongs can understand that the present invention can be embodied in other specific forms without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the above embodiments are illustrative in all respects and not limiting.

Claims (13)

A base film;
a first wiring pattern extending in a first direction on one surface of the base film;
a first via pad connected to the first wiring pattern at a connection region and having a polygonal shape;
a first via hole passing through the base film and overlapping the first via pad;
The first via pad is
a width in a second direction perpendicular to the first direction, the width in the second direction decreasing toward the first direction in a central region;
The first via pad is
a first side and a second side that contact the first wiring pattern in the connecting region;
a third side extending substantially parallel to the first side;
a fourth side extending substantially parallel to the second side,
the first side and the fourth side are in contact with each other at a first vertex,
a distance between the first via hole and the first vertex is greater than a distance between the first via hole and the first side;
the first wiring pattern has a linear shape along the first direction and extends to a vicinity of the connecting region,
a third wiring pattern extending on the one surface of the base film ;
a second via pad is connected to the third wiring pattern;
the first wiring pattern and the third wiring pattern extend in the same direction, the first wiring pattern is connected to the first via pad, and the third wiring pattern is connected to the second via pad;
the first via pad is disposed at an acute angle with respect to the first wiring pattern;
The second via pad is disposed at an acute angle with respect to the third wiring pattern . The flexible circuit board according to claim 1, wherein the second side and the third side meet at a second vertex. The first via pad is
Further including a fifth side;
The flexible circuit board according to claim 1 , wherein at least one pair of the first to fourth sides are connected via the fifth side. the first side is spaced a first distance from the center of the first via pad;
the fifth side and the center of the first via pad are spaced apart by a second distance;
The flexible circuit board of claim 3 , wherein the second distance is greater than the first distance. The first via pad is
The flexible circuit board according to claim 1 , further comprising an arc connecting at least a pair of the first to fourth sides. the first side is spaced a first distance from the center of the first via pad;
The flexible circuit board of claim 5 , wherein a radius of curvature of the arc is less than the first distance. a second wiring pattern formed on the other surface of the base film opposite to the one surface,
The flexible circuit board according to claim 1 , wherein the first wiring pattern and the second wiring pattern are electrically connected to each other through the first via pad. A base film;
a first wiring pattern extending in a first direction on one surface of the base film;
a via pad having a polygonal shape and at least a portion of which is connected to the first wiring pattern;
a via hole passing through the base film and overlapping the via pad;
the first wiring pattern has a linear shape along the first direction and extends to a vicinity of the via pad,
The via pad is
a first side and a second side extending parallel to each other and forming an acute angle with the first direction;
a third side extending perpendicular to the extension direction of the first side and the second side,
the second side and the third side are in contact with each other at a second vertex,
a distance between the via hole and the second vertex is greater than a distance between the via hole and the third side;
the first side and the second side extend from the first wiring pattern,
The length of the second side is longer than the length of the first side,
a flexible circuit board, wherein the acute angle formed by the first side with respect to the first wiring pattern and the acute angle formed by the second side with respect to the first wiring pattern are substantially the same . The via pad further includes a fifth side,
The flexible circuit board according to claim 8 , wherein at least one pair of the first, second, and third sides are connected via the fifth side. the third side and a center of the via pad are spaced apart by a first distance;
the fifth side and the center of the via pad are spaced apart by a second distance;
The flexible circuit board of claim 9 , wherein the first distance is less than the second distance. The flexible circuit board according to claim 10, wherein the via pad further includes an arc connecting at least a pair of the first to third sides. The flexible circuit board according to claim 11, wherein the radius of curvature of the arc is smaller than the separation distance between the first side and the center of the via pad. The via pad is
The flexible circuit board of claim 8 , further comprising a width in a second direction perpendicular to the first direction, the width in the second direction decreasing in a central region toward the first direction.