Flexible circuit board

Abstract

To provide a flexible circuit board.SOLUTION: A flexible circuit board 100 includes a flexible substrate 110, a chip 120, a first test pad setting area t1, a plurality of first test pads 131, and a wiring layer 140. The flexible substrate 110 has an upper surface. The upper surface has a working area and a non-working area. The chip 120 is disposed on the working area. The first test pad setting area t1 is located within the non-working area and between a third edge end 113 of the flexible substrate 110 and the working area. These first test pads 131 are arranged on the first test pad setting area t1, and the wiring layer 140 is connected to the chip 120 and these first test pads 131. The size of the first test pad setting area t1 cannot be changed with the size variation of the flexible circuit board 100.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flexible circuit board, and more particularly to a flexible board having test pads. [Background technology]

[0002] Flexible circuit boards have the advantages of flexibility and small volume, and are therefore widely used in home appliances, but because of their small volume, the circuit lines on the flexible circuit boards are also very fine, making it difficult to directly test the circuit lines during the manufacturing process. Therefore, before cutting the flexible circuit board into the size of an actual circuit board, test pads are installed outside the working area of ​​the subsequent actual cut circuit board, and a probe card is contacted to perform electrical testing, so the size of the test pads is made larger than the width of the circuit lines and they are installed at the top and bottom two edges of the flexible circuit board. Summary of the Invention [Problem to be solved by the invention]

[0003] However, flexible circuit boards are designed in different sizes for different applications, and the difference in size changes the distance between the two upper and lower edges of the flexible circuit board, so flexible circuit boards of different sizes need to be tested using probe cards of different specifications, which increases the cost of testing flexible circuit boards. In addition, if the distance between the two upper and lower edges of a large-sized flexible circuit board is long, the probe card can only test one or two flexible circuit boards at a time, which significantly increases the time required for testing.

[0004] Therefore, the present inventors believed that the above-mentioned drawbacks could be improved, and as a result of extensive research, they came to propose the present invention, which effectively improves the above-mentioned problems through rational design.

[0005] The present invention has been made in view of the above circumstances, and aims to solve the above problems as an example of an objective of the present invention. That is, the main objective of the present invention is to provide a flexible board in which a test pad setting area is set between a third edge of the flexible board and a working area, so that the size of the test pad setting area is not limited by the size of the flexible board, and a probe card of the same standard can be applied to flexible boards of different sizes. [Means for solving the problem]

[0006] In order to achieve the above object, a flexible circuit board according to an embodiment of the present invention includes a flexible board, a chip, a first test pad setting area, a plurality of first test pads, and a wiring layer. The flexible substrate has a top surface and a first edge, a second edge, a third edge, and a fourth edge. The top surface has a working area and a non-working area, the non-working area surrounding the working area, and the working area has a first cutting surface and a second cutting surface. The first cutting surface and the second cutting surface are parallel to the first edge and the second edge, and the third edge and the fourth edge are located between the first edge and the second edge. The chip is placed on the working area, the chip having two longitudinal directions, an active surface, and a number of first bumps, the longitudinal directions of the chip being parallel to the first and second edges of the top surface, the active surface facing the top surface, the first bumps being placed on the active surface and adjacent to one of the longitudinal directions and aligned along one of the longitudinal directions. The first test pad setting area is located in the non-working area and between the third edge and the working area. The first test pads are disposed in the first test pad setting area and are arranged along the third edge. The wiring layer is disposed on the upper surface, and the wiring layer has a plurality of first outer leads, a plurality of first circuit lines, and a plurality of first extension lines, the first outer leads are adjacent to the first cutting surface and arranged along the first cutting surface, one end of each of the first circuit lines is connected to a respective one of the first bumps, the other end of each of the first circuit lines is connected to a respective one of the first outer leads, one end of each of the first extension lines is connected to the other end of the first outer lead, and the other end of each of the first extension lines is connected to a respective one of the first test pads. Effect of the Invention

[0007] As described above, the present invention has the following advantages. Since the first test pad setting area is located between the third edge and the working area, the size of the first test pad setting area does not change according to the change in size of the flexible circuit board, and the same standard probe card can be applied to flexible circuit boards of different sizes, thereby reducing the cost of testing.

[0008] Other objects, configurations and effects of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention. [Brief description of the drawings]

[0009] [Figure 1] 1 is a top view showing a flexible circuit board according to a first embodiment of the present invention. [Diagram 2] 1 is a partially enlarged cross-sectional view showing a flexible circuit board according to a first embodiment of the present invention. [Diagram 3] FIG. 11 is a top view showing a flexible circuit board according to a second embodiment of the present invention. [Figure 4] FIG. 11 is a top view showing a flexible circuit board according to a third embodiment of the present invention. [Diagram 5] FIG. 11 is a top view showing a flexible circuit board according to a fourth embodiment of the present invention. [Figure 6]FIG. 11 is a schematic diagram showing a configuration in which a plurality of flexible circuit boards according to a second embodiment of the present invention are connected to one another on a reel. [Figure 7] FIG. 13 is a schematic diagram showing a configuration in which a plurality of flexible circuit boards according to a fourth embodiment of the present invention are connected to one another on a reel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0011] (First embodiment) FIG. 1 is a top view showing a flexible circuit board 100 according to a first embodiment of the present invention. FIG. 2 is a partially enlarged cross-sectional view showing the flexible circuit board 100 according to the first embodiment of the present invention.

[0012] The flexible circuit board 100 includes a flexible substrate 110, a chip 120, a first test pad setting area t1, a plurality of first test pads 131, a plurality of second test pads 132, and a wiring layer 140. The flexible substrate 110 has a top surface 111, a first edge 112, a second edge 113, a third edge 114, and a fourth edge 115. The third edge 114 and the fourth edge 115 are located between the first edge 112 and the second edge 113, and the first edge 112, the second edge 113, the third edge 114, and the fourth edge 115 are four sides surrounding the top surface 111, and based on the direction of the flexible circuit substrate 100 in FIG. 1, the first edge 112 and the second edge 113 are the lower edge and the upper edge of the top surface 111, respectively, and the third edge 114 and the fourth edge 115 are the left edge and the right edge of the top surface 111, respectively.

[0013] The upper surface 111 has a working area w1 and a non-working area w2, the working area w1 is located at the center of the upper surface 111, and the non-working area w2 surrounds the working area w1. The area surrounded by the dashed line is the working area w1, and the area outside the dashed line is the non-working area w2. The working area w1 is the area of ​​the actual circuit board that is subsequently cut from the flexible circuit board 100. In this embodiment, the working area w1 has a rectangular shape, which is merely an outline of this embodiment, and the shape of the circuit board is not limited in the present invention. The working area w1 has a first cut surface c1, a second cut surface c2, a third cut surface c3, and a fourth cut surface c4, where the first cut surface c1 and the second cut surface c2 are parallel to the first edge 112 and the second edge 113, and the third cut surface c3 and the fourth cut surface c4 are parallel to the third edge 114 and the fourth edge 115.

[0014] The chip 120 is placed in the working area w1, and the chip 120 has two longitudinal directions 121, an active surface 122, a plurality of first bumps 123, and a plurality of second bumps 124. The two longitudinal directions 121 of the chip 120 are parallel to the first edge 112 and the second edge 113 of the flexible substrate 110, and the active surface 122 faces the upper surface 111 of the flexible substrate 110. The first bumps 123 are placed on the active surface 122 and adjacent to one of the longitudinal directions 121, and are arranged along the one of the longitudinal directions 121. The second bumps 124 are placed on the active surface 122 and adjacent to the other longitudinal direction 121, and are arranged along the other longitudinal direction 121. In the drawings, only four of the first bumps 123 and four of the second bumps 124 are depicted, and the rest are indicated by continuous black dots.

[0015] The first test pad setting area t1 is located in the non-working area w2, and is located between the third edge 114 and the working area w1. In this embodiment, the first test pad setting area t1 is rectangular, and a longitudinal direction of the first test pad setting area t1 is parallel to the third edge 114. The first test pads 131 and the second test pads 132 are disposed in the first test pad setting area t1, and are arranged along the third edge 114. The first test pads 131 are closer to the first edge 112 than the second test pads 132, and the second test pads 132 are closer to the second edge 113 than the first test pads 131. In the drawings, only four of the first test pads 131 and four of the second test pads 132 are depicted, and the rest are indicated by continuous black dots. In addition, in this embodiment, the first test pads 131 and the second test pads 132 are designed in a single row, however, in other embodiments, if there is a lack of space, the first test pads 131 and the second test pads 132 may be designed in multiple rows.

[0016] The wiring layer 140 is disposed on the upper surface 111 of the flexible substrate 110, and the wiring layer 140 has a plurality of first outer leads 141, a plurality of first circuit lines 142, a plurality of first extension lines 143, a plurality of second outer leads 144, a plurality of second circuit lines 145, and a plurality of second extension lines 146. The first outer leads 141 are located in the working area w1, adjacent to the first cutting surface c1, and arranged along the first cutting surface c1. The first outer leads 141 are members that are connected to a circuit board of another electronic device after being cut in the subsequent working area w1, and only four of the first outer leads 141 are depicted in the drawing, and the rest are represented by continuous black dots. The first circuit lines 142 are located in the working area w1, and the first extension lines 143 are located in the non-working area w2. One end of each of the first circuit lines 142 is connected to a respective one of the first bumps 123, the other end of each of the first circuit lines 142 is connected to a respective one of the first outer leads 141, one end of each of the first extension lines 143 is connected to the other end of the first outer lead 141, and the other end of each of the first extension lines 143 is connected to a respective one of the first test pads 131. In order to prevent the drawing from becoming cluttered, only four of the first circuit lines 142 and four of the first extension lines 143 are depicted in the drawing. In reality, one first circuit line 142 is connected between each of the first bumps 123 and each of the first outer leads 141, and one first extension line 143 is connected between each of the first outer leads 141 and each of the first test pads 131. In this embodiment, the first circuit lines 142, the first outer leads 141, and the first extension lines 143 enable each of the first bumps 123 to be coupled to each of the first test pads 131, and the first test pads 131 are used to test whether there are any abnormalities in the electrical connections between the circuit lines and the first bumps 123.

[0017] These second outer leads 144 are located in the working area w1, adjacent to the second cutting surface c2, and arranged along the second cutting surface c2. These second outer leads 144 are also components that are cut in the subsequent working area w1 and then connected to a circuit board of another electronic component. In the drawing, only four of the second outer leads 144 are depicted, and the rest are indicated by continuous black dots. The second circuit lines 145 are located in the working area w1, and the second extension lines 146 are located in the non-working area w2. One end of each of the second circuit lines 145 is connected to each of the second bumps 124, the other end of each of the second circuit lines 145 is connected to each of the first ends of the second outer leads 144, one end of each of the second extension lines 146 is connected to the other end of the second outer leads 144, and the other end of each of the second extension lines 146 is connected to each of the second test pads 132. In the drawing, only four of the second circuit lines 145 and four of the second extension lines 146 are shown to prevent the drawing from becoming cluttered. In reality, one second circuit line 145 is connected between each of the second bumps 124 and each of the second outer leads 144, and one second extension line 146 is connected between each of the second outer leads 144 and each of the second test pads 132. The second circuit lines 145, the second outer leads 144, and the second extension lines 146 allow the second bumps 124 to be coupled to the second test pads 132, and the second test pads 132 test whether there is an abnormality in the electrical connection between the circuit lines and the second bumps 124.

[0018] In this embodiment, the first test pads 131 and the second test pads 132 are concentrated in the first test pad setting area t1, and when the size of the flexible circuit board 110 increases, the size of the first test pad setting area t1 remains unchanged due to wiring design, and a probe card of the same size can be used to test the flexible circuit boards 100 of different sizes, thereby reducing the cost of testing the flexible circuit board 100.

[0019] (Second Example) FIG. 3 is a top view showing a flexible circuit board 100 according to a second embodiment of the present invention. The flexible circuit board 100 further includes a second test pad setting area t2, which is located in the non-working area w2 and between the second edge 113 and the second cutting surface c2 of the working area w1. The second test pad setting area t2 is rectangular, and the longitudinal direction of the second test pad setting area t2 is parallel to the second edge 113, which is different from the first embodiment.

[0020] In this embodiment, a plurality of third test pads 133 are installed in the second test pad setting area t2, and these third test pads 133 are arranged along the second edge 113, and only these first test pads 131 are installed in the first test pad setting area t1, and these second test pads 132 are not installed. In this manner, one end of each of the second extension lines 146 in this embodiment is connected to the other end of the second outer lead 144, and the other end of each of the second extension lines 146 is connected to each of the third test pads 133. When the circuit lines are too dense to place all of the test pads in the first test pad setting area t1, the third test pads 133 are placed in the second test pad setting area t2, and the third test pads 133 and the second extension lines 146 are used to test whether there are any abnormalities in the electrical connections of the second outer leads 144, the second circuit lines 145, and the second bumps 124. Preferably, only the first test pads 131 are installed in the first test pad setting area t1, so that the first test pad setting area t1 is installed in a position adjacent to the second test pad setting area t2 in the upper half of the upper surface 111, and a probe card can simultaneously test the first test pads 131 in the first test pad setting area t1 and the third test pads 133 in the second test pad setting area t2.

[0021] (Third Example) FIG. 4 is a top view showing a flexible circuit board 100 according to a third embodiment of the present invention. The flexible circuit board 100 further includes a third test pad setting area t3, which is located in the non-working area w2 and between the fourth edge 115 and the working area w1. The third test pad setting area t3 is rectangular, and differs from the first embodiment in that the longitudinal direction of the third test pad setting area t3 is parallel to the fourth edge 115.

[0022] In this embodiment, the first test pads 131 and the second test pads 132 are installed in the first test pad setting area t1, and are respectively connected to the first outer lead 141 and the second outer lead 144 by the first extension line 143 and the second extension line 146.

[0023] A plurality of fourth test pads 134 and a plurality of fifth test pads 135 are installed in the third test pad setting area t3, and the fourth test pads 134 and the fifth test pads 135 are arranged along the fourth edge 115. The wiring layer 140 further has a plurality of third extension lines 147 and a plurality of fourth extension lines 148, one end of each of the third extension lines 147 is connected to the other end of the first outer lead 141, the other end of each of the third extension lines 147 is connected to each of the fourth test pads 134, one end of each of the fourth extension lines 148 is connected to the other end of the second outer lead 144, and the other end of each of the fourth extension lines 148 is connected to each of the fifth test pads 135.

[0024] In this embodiment, the test pads of the first bumps 123, the first circuit lines 142, and the first outer leads 141 of the chip 120 are separately set in the first test pad setting area t1 and the third test pad setting area t3, and the test pads of the second bumps 124, the second circuit lines 145, and the second outer leads 144 are respectively set in the first test pad setting area t1 and the third test pad setting area t3, thereby solving the problem that one test pad setting area cannot accommodate all the test pads. In addition, the first test pad setting area t1 and the third test pad setting area t3 are located on both the left and right sides of the working area w1, and due to the wiring design, the sizes of the first test pad setting area t1 and the third test pad setting area t3 do not change according to the change in the size of the flexible circuit board 100, so that testing can be performed on flexible circuit boards 100 of different sizes using probe cards of the same standard.

[0025] (Fourth Example) FIG. 5 is a top view showing a flexible circuit board 100 according to a fourth embodiment of the present invention. The flexible circuit board 100 further includes a second test pad setting area t2, which is located in the non-working area w2 and between the second edge 113 and the second cutting surface c2 of the working area w1. A plurality of third test pads 133 are provided in the second test pad setting area t2, and the third test pads 133 are arranged along the second edge 113. This embodiment differs from the third embodiment in that one end of each of the second extension lines 146 of the wiring layer 140 is connected to the other end of the second outer lead 144, and the other end of each of the second extension lines 146 is connected to each of the third test pads 133. By installing the third test pads 133 in the second test pad setting area t2, only the first test pads 131 are installed in the first test pad setting area t1, and only the fourth test pads 134 are installed in the third test pad setting area t3. In this manner, the first test pad setting area t1 and the third test pad setting area t3 are positioned adjacent to the second test pad setting area t2 in the upper half of the upper surface 111, so that a probe card can simultaneously test the first test pads 131 in the first test pad setting area t1, the third test pads 133 in the second test pad setting area t2, and the fourth test pads 134 in the third test pad setting area t3.

[0026] FIG. 6 is a schematic diagram showing a configuration in which a plurality of flexible circuit boards 100 according to a second embodiment of the present invention are connected to a reel R. A connection edge ce is provided between two adjacent flexible circuit boards 100, and the first test pad setting area t1 and the second test pad setting area t2 of the two adjacent flexible circuit boards 100 are mirror-symmetric with respect to the connection edge ce. Since all of the test pads in the second embodiment are concentrated on half of the top surface 111 of the flexible substrate 110, one probe card can be used to test the test pads of two of the flexible circuit substrates 100 simultaneously, accelerating the test flow chart and improving the overall process efficiency.

[0027] FIG. 7 is a schematic diagram showing a configuration in which a plurality of flexible circuit boards 100 according to a fourth embodiment of the present invention are connected to a reel R. There is a connection edge ce between two adjacent flexible circuit boards 100, and the first test pad setting area t1 and the second test pad setting area t2 of the two adjacent flexible circuit boards 100 are mirror-symmetric with respect to the connection edge ce. Since all of the test pads in the fourth embodiment are concentrated on half of the top surface 111 of the flexible substrate 110, one probe card can be used to test the test pads of two of the flexible circuit substrates 100 simultaneously, accelerating the test flow chart and improving the overall process efficiency.

[0028] In the present invention, since the first test pad setting area t1 is installed between the third edge 114 and the working area w1, the size of the first test pad setting area t1 does not change according to the change in the size of the flexible circuit board 100, and the same standard probe card can be applied to the flexible circuit boards 100 of different sizes, thereby reducing the cost of testing.

[0029] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the claims that such modifications and improvements can also be included in the technical scope of the present invention. [Explanation of symbols]

[0030] 100 Flexible Circuit Board 110 Flexible PCB 111 Top surface 112 1st edge 113 Second edge 114 Third edge 115 4th edge 120 Chips 121 Longitudinal 122 Active Surface 123 First Bump 124 2nd Bump 131 Test Pad No. 1 132 2nd Test Pad 133 3rd Test Pad 134 4th Test Pad 135 5th Test Pad 140 wiring layer 141 1st outer lead 142 1st circuit line 143 1st extension line 144 2nd outer lead 145 2nd circuit line 146 Second extension line 147 Third extension line 148 4th extension line w1 work area w2 non-work area c1 1st cutting plane c2 2nd cutting plane c3 3rd cutting plane c4 4th cutting plane t1 First test pad setting area t2 Second test pad setting area t3 Third test pad setting area R Reel ce Connection Edge

Claims

1. a flexible substrate having a top surface, a first edge, a second edge, a third edge, and a fourth edge, the top surface having a working area and a non-working area, the non-working area surrounding the working area, the working area having a first cutting surface and a second cutting surface, the first cutting surface and the second cutting surface being parallel to the first edge and the second edge, and the third edge and the fourth edge being located between the first edge and the second edge; a chip disposed on the working area, the chip having two longitudinal directions, an active surface, and a plurality of first bumps, the longitudinal directions being parallel to the first edge and the second edge, the active surface facing the upper surface, the first bumps being disposed on the active surface and adjacent to one of the longitudinal directions, and the first bumps being arranged along one of the longitudinal directions; a first test pad setting area located in the non-working area and between the third edge and the working area; a plurality of first test pads disposed in the first test pad setting area and arranged along the third edge; a wiring layer disposed on the upper surface, the wiring layer having a plurality of first outer leads, a plurality of first circuit lines, and a plurality of first extension lines, the first outer leads being adjacent to the first cutting surface and being arranged along the first cutting surface, one end of each of the first circuit lines being connected to a respective one of the first bumps, the other end of each of the first circuit lines being connected to a respective one of the first outer leads, one end of each of the first extension lines being connected to the other end of the first outer leads, and the other end of each of the first extension lines being connected to a respective one of the first test pads; A flexible circuit board comprising:

2. the chip further comprises a plurality of second bumps disposed on the active surface and adjacent to each other in the longitudinal direction, the second bumps being arranged along the other longitudinal direction; 2. The flexible circuit board according to claim 1, wherein a plurality of second test pads are further provided in the first test pad setting area, and the second test pads are arranged along the third edge, the wiring layer further has a plurality of second outer leads, a plurality of second circuit lines, and a plurality of second extension lines, the second outer leads are adjacent to the second cutting surface and arranged along the second cutting surface, one end of each of the second circuit lines is connected to a respective one of the second bumps, the other end of each of the second circuit lines is connected to a respective one of the second outer leads, one end of each of the second extension lines is connected to the other end of the second outer lead, and the other end of each of the second extension lines is connected to a respective one of the second test pads.

3. a second test pad setting area located in the non-working area and between the second edge and the second cutting surface of the working area; the chip further comprises a plurality of second bumps disposed on the active surface and adjacent to each other in the longitudinal direction, the second bumps being arranged along the other longitudinal direction; a plurality of third test pads are provided in the second test pad setting area, the third test pads being arranged along the second edge; 2. The flexible circuit board according to claim 1, wherein the wiring layer further includes a plurality of second outer leads, a plurality of second circuit lines, and a plurality of second extension lines, the second outer leads being adjacent to the second cut surface and arranged along the second cut surface, one end of each of the second circuit lines being connected to a respective one of the second bumps, the other end of each of the second circuit lines being connected to a respective one of the second outer leads, one end of each of the second extension lines being connected to the other end of the second outer lead, and the other end of each of the second extension lines being connected to a respective one of the third test pads.

4. 4. The flexible circuit board according to claim 3, characterized in that a reel is formed by connecting a plurality of the flexible circuit boards to each other, and the first test pad setting area and the second test pad setting area of ​​two adjacent flexible circuit boards are mirror-symmetrical with respect to a connection edge between the two adjacent flexible circuit boards.

5. a third test pad setting area located in the non-working area and between the fourth edge and the working area; 2. The flexible circuit board according to claim 1, wherein a plurality of fourth test pads are provided in the third test pad setting area, the fourth test pads being arranged along the fourth edge, the wiring layer further having a plurality of third extension lines, one end of each of the third extension lines being connected to the other end of the first outer lead, and the other end of each of the third extension lines being connected to each of the fourth test pads.

6. the chip further comprises a plurality of second bumps disposed on the active surface and adjacent to the other longitudinal direction, the second bumps being arranged along the other longitudinal direction; a plurality of second test pads are further provided in the first test pad setting area, the second test pads being arranged along the third edge; 6. The flexible circuit board according to claim 5, wherein the wiring layer further includes a plurality of second outer leads, a plurality of second circuit lines, and a plurality of second extension lines, the second outer leads being adjacent to the second cut surface and arranged along the second cut surface, one end of each of the second circuit lines being connected to a respective one of the second bumps, the other end of each of the second circuit lines being connected to a respective one of the second outer leads, one end of each of the second extension lines being connected to the other end of the second outer lead, and the other end of each of the second extension lines being connected to a respective one of the second test pads.

7. 7. The flexible circuit board of claim 6, wherein a plurality of fifth test pads are further installed in the third test pad setting area, the fifth test pads being arranged along the fourth edge, the wiring layer further having a plurality of fourth extension lines, one end of each of the fourth extension lines being connected to the other end of the second outer lead, and the other end of each of the fourth extension lines being connected to each of the fifth test pads.

8. a second test pad setting area located in the non-working area and between the second edge and the second cutting surface of the working area; the chip further comprises a plurality of second bumps, the second bumps being disposed on the active surface and adjacent to each other in the longitudinal direction, the second bumps being arranged along the longitudinal direction; a plurality of third test pads being disposed in the second test pad setting area, the third test pads being arranged along the second edge; 6. The flexible circuit board according to claim 5, wherein the wiring layer further includes a plurality of second outer leads, a plurality of second circuit lines, and a plurality of second extension lines, the second outer leads being adjacent to the second cut surface and arranged along the second cut surface, one end of each of the second circuit lines being connected to a respective one of the second bumps, the other end of each of the second circuit lines being connected to a respective one of the second outer leads, one end of each of the second extension lines being connected to the other end of the second outer lead, and the other end of each of the second extension lines being connected to a respective one of the third test pads.

9. 9. The flexible circuit board according to claim 8, characterized in that a reel is formed by connecting a plurality of the flexible circuit boards to each other, and the first test pad setting area, the second test pad setting area, and the third test pad setting area of ​​two adjacent flexible circuit boards are mirror-symmetrical with respect to a connection edge between the two adjacent flexible circuit boards.

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