TWI339552B - Flexible circuit board - Google Patents

Description

27801 twf.doc/d IX. Description of the Invention: [Technical Field] The present invention relates to a flexible circuit board, and more particularly to a flexible circuit board having a special structure to slow down its mechanical stress. [Prior Art] With the development of packaging technology, chip on film (COF) thermocompression bonding technology has become one of the advanced packaging technologies. In general, the application of flip-chip thin film thermo-welding technology is very wide. For example, the electrical connection between the liquid crystal panel and the integrated circuit (1C) is one of the applications of COF thermo-compression welding technology. . 1 and 2 are referred to. 1 is a cross-sectional view of the electronic device 4, and FIG. 2 is a cross-sectional view of another electronic device 6. For example, each of the electronic devices 4 and 6 may be a display II such as a thin film transistor liquid crystal display (TFT), or an organic light-emitting diode display OLED. Each of the electronic devices 4 and 6 has a display panel 1 printed circuit board (PCB), a drive IC 12, and a circuit board 14. The PCB 1G has a built-in time controller to generate the number to control the operation of the driver IC 12. The flexible circuit board 14 can be bent. In this case, the PCB 1G can be placed above the electronic device 4 (as shown in Figure H) or placed on the back of the display panel 8 (as shown in Figure 2). Drive 1C 12 is formed on flexible circuit board 14 and is built according to pcB 1〇 2780ltwf, d〇c/cl 2780ltwf, d〇c/cl

Time signal received by the controller to drive the IC

Work.丄Z Referring to FIG. 3, FIG. 3 is a schematic view of the display panel 8, the PCB 1A, the drive, and the flexible circuit board 14. The driving Ic 12 board 14 is formed on the board 14 and electrically connected to the display panel 8 via a plurality of wires and via the plurality of wires 18, and has an outer bow foot la, an inner pin lb, and a connecting portion lc. Connection] = outer pin la and inner pin lb. As shown in FIG. 3, the foot degree is greater than the width of the inner pin lb, and the wire 16 is scaled and has a corner of =. However, when the flexible circuit board 14 is bent, due to the high stress density caused by the 1 turn angle, the joint between the outer lead la and the connecting portion lb and the connecting portion lc is easily broken. ¥ The signal transmission on the PCB 10 and _ IC 12 failed. A flexible circuit board is disclosed in the laid-open patent application No. HU/345839. Referring to Figures 4 and 5, Figure 4 is an illustration of the flexible circuit board of the above-mentioned disclosed patent document, and Figure 5 is an enlarged view of the wire of the flexible circuit board of Figure 4. As shown in Fig. 4, the two wires of the flexible circuit board respectively form corresponding notches 2. Each of the recesses 2 is an inner concave portion to relieve the mechanical stress of the inner edge 2a and the joint portion lc of the joint portion of the outer lead la. However, the inner lead is sharper than the joint hole $ and the connecting portion lc, and therefore is affected by high stress concentration, and increases the probability of the joint 2b breaking under the applied force. SUMMARY OF THE INVENTION 1339552 2780 Uwf.doc/d The present invention provides a flexible circuit board which can reduce the probability of breakage of the joint portion of the outer lead and the joint portion under the force applied. The present invention provides a flexible circuit board which reduces the probability of breakage of the joint portion of the inner lead and the joint portion under the force applied. Thus, the present invention proposes a flexible circuit board. The flexible circuit board includes a flexible thin package, a plurality of inner leads, a plurality of outer leads, and a plurality of connections 4. The inner leads are formed on the flexible film and each inner pin has a first-thick width. The outer leads are formed on the flexible film and each outer lead has a second width greater than the first width. Each connection is connected to its corresponding - inner pin and its corresponding outer pin. At least one of the plurality of connecting portions is connected.卩 has an inner edge and an outer edge. The outer edge has a first rounded area, a second rounded area, and a first-------------------- The inner edge has a second circular convex region, a third circular & region, and a third circular concave region between the second circular convex portion and the third circular convex portion. In an embodiment of the invention, the radius of curvature of the first circular convex region is greater than the radius of curvature of the third circular concave region. In the present invention, the outer edge further includes a fourth circular convex region between the first circular convex S· and the first circular concave region. In an embodiment of the invention, the inner edge further includes a fourth circular recess located between the third circular recess and the third circular convex region. In the embodiment of the invention, the inner edge and the outer edge are opposed to each other. In an embodiment of the invention, each inner edge of the meandering connection portion has at least a concave area and at least a round convex area, and each of the other connecting portions has at least one concave area and at least one circular convex area. . 27801twf.doc/cl 27801twf.doc/cl Points can be more obvious and easy to understand, as detailed below, as detailed below. The above features and preferred embodiments of the present invention have been made in accordance with the accompanying drawings. [Embodiment] Referring to Fig. 6, Fig. 6 is a schematic view of a flexible circuit board according to a first embodiment of the present invention. The flexible circuit board W has a plurality of inner leads 36, a plurality of connecting portions 38, and a plurality of outer leads 4A. Each of the connections is connected to its corresponding ir, inner pin 36 and its corresponding outer pin 4'. As shown in Figure 6, the group 32 of ports 38 is located between the group 3 of the inner leg 36 and the group 34 of the outer pins 4A. Each (four) leg 36 has a first width wi and each outer pin 40 has a second width W2. The first [width W2A is at the first width. According to a further preferred embodiment of the invention, the ratio of the second width to the second degree W1 is greater than or equal to three. However, the invention is not limited thereto. The inner lead 36 or the outer lead 40 are parallel and equidistantly spaced. In other words, there is a first spacing D1 along the first coordinate axis = between two adjacent force inner pins 36 and there is a first along the two adjacent outer pins 4 The second pitch D2 of the coordinate axis. In addition, the inner pin and the outer pin 40 extend along the second coordinate axis γ. It is worth noting that the pitch of the adjacent leads 36 of the inner lead 36 or the outer lead 40 in this month is not limited to any special spacing. For example, the inner pin 36 or the outer pin can be spaced apart at various intervals. Refer to Figure 7 and Figure 8. Figure 7 is a cross-sectional view of the flexible circuit board 2 〇 along the Α-Α line segment of Figure 6, and Figure 8 is a cross-sectional view of the flexible circuit board along the Β-Β' line of Figure 6. The flexible circuit board 20 is more flexible 1339552 2780ltwf.doc/d film 22 and solder resistor (S〇lderresisi, SR) layer. The material of the flexible film 22 is a polyamidide and has a thick leg 36 and an outer lead 40 which are formed on the flexible film 22, and the tin resist layer 24 is reapplied. In addition, in this embodiment, the inner pin %, the connection and the outer pin 40 are made of copper metal and have a thickness of 5 to lion. However, it should be noted that the above-described embodiments of the present invention are not limited thereto.

Referring again to Figure 6, the connection portion 38 of the group 32 of the connection portions 38 is connected to the inner lead 36 of the group 30 of the inner leads 36, and the outer pins ,, 34 of the legs 4 '. Along the first coordinate axis, the inner pin %, the position range on the coordinate axis X, partially or entirely overlaps the position range of the outer pin 4 〇 on the first standard axis X. However, as seen along the second coordinate axis γ, the connecting portion 38' separates the inner lead 36 from the outer lead 4'. Referring to Fig. 9, Fig. 9 is an enlarged view of the vicinity of the connecting portion 38. The connecting portion % has an inner edge 42 and an outer edge 44. Inner edge 42 and outer edge 44 are mutually

relatively. The inner edge 42 is connected to the inner side of the inner lead 36 and the right side of the outer lead 40'. The outer edge 44 and the inner lead 36 are connected to the left side of the left and outer pins 4'. Xi. The edge 44 has a first circular recess 5, a first circular convex portion 52, and a second circular concave portion 54. The first circular convex region η is located between the first concave area 5〇 and the second circular concave area. The inner edge 42 has a second circular convex portion 56, a third circular concave portion 58 and a third circular convex portion 60 The concave area 58 is located between the second circular convex portion 56 and the third circular convex portion 60. Referring to Fig. 10, Fig. 10 is a schematic view of the first circular convex portion 52 and the third circular concave portion 58. The first circular convex portion The region 52 has a radius of curvature R1, and the third circular region has a radius of curvature R2, such as having a radius of curvature R2, wherein the radius of curvature R1 is greater than the radius of curvature R2. Referring to FIG. 11', FIG. 11 is within the second embodiment of the present invention. A schematic diagram of the pin 36, the connecting portion 38, and the outer pin 40'. In this embodiment, the inner edge 42 is connected to the left side of the inner lead 36, the left side of the outer lead 40', and the outer edge 44 and the inner lead The right side of the leg 36' and the right side of the outer pin 40' are connected.

Referring to Fig. 12', Fig. 12 is a schematic view showing the inner pin %, the connecting portion 38, and the outer pin 40' according to the third embodiment of the present invention. In this embodiment, the inner edge is connected to the right side of the inner pin 36' and the right side of the outer pin 40', and the outer edge is connected to the left side of the inner leg 36' and the left side of the outer pin 40'. In addition, the outer edge material 'has a fourth circular projection 53 between the first circular convex portion 52 and the second circular concave portion 54. In the present embodiment, the connecting first circular convex portion 52 and the fourth circular convex portion magic product region 55 are in a straight line. However, it should be noted that the present invention is not by way of example. For example, the intermediate portion 55 may be another circular convex region. Referring to Figure 13, there is shown a schematic view of an inner bow, a connecting portion 38' and an outer lead 40' in accordance with a fourth embodiment of the present invention. In this embodiment, 36, only 015 bucket edge 42 blood

The inner bow foot 36, the left and outer pins 40, are connected to the left side, and the outer edges are connected to the right side such as the foot 36, the right side and the outer side pin 40. Further, the outer edge material, the inner bow has a fourth circular convex portion 53 and an intermediate portion 55. The fourth circular convex portion 53 is located between the region 52 and the second concave portion 54. Round convexity Referring to Fig. 14', Fig. 14 is a view showing the inner connecting portion 38 and the outer lead 4'' according to the fifth embodiment of the present invention. In this embodiment, the inner=36', the inner lead 36, the right side and the outer lead 40 are connected to the right side, and the outer edge material edge 42 is

The left side of the leg 36, the outer pin 40, is connected to the left side. In addition, the inner and inner bows I are located between the third circular recessed area 58 and the third circular convex area 6〇, and have a J-four circular recessed area 10 2780ltwf.doc/d a η π', long time, when When the flexible circuit board is bent, the mechanical stress near the corner where the pin and the outer pin are joined is slowed down. Therefore, not σ pjq g I. Α Α 〃 〃 〃 〃 〃 〃 〃 〃 〃 〃 〃 〃 〃 接合 接合 接合 接合 接合 接合 接合 接合 接合 接合 接合 接合 接合 接合 接合 接合 接合 接合

Although the present invention has been disclosed in the preferred embodiments as above, and the invention is not limited to the spirit and scope of the present invention, without departing from the spirit and scope of the present invention. A few lines and retouching, so the scope of the invention is as determined by the viewer. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of a conventional electronic device. 2 is a schematic cross-sectional view of another conventional electronic device. Figure 3 is a schematic illustration of the display panel, PCb, drive 1C, and flexible circuit board of the electronic device of Figure 1 or Figure 2. Fig. 4 is a schematic view of a flexible circuit board disclosed in Japanese Laid-Open Patent Application. Figure 5 is an enlarged view of the wires of the flexible circuit board of Figure 4. Figure 6 is a schematic view of a flexible circuit board in accordance with a first embodiment of the present invention. Figure 7 is a cross-sectional view of the flexible circuit board taken along line Α_Α' in Figure 6. Figure 8 is a cross-sectional view of the flexible circuit board taken along line Β-Β in Figure 6. [S1 12 1339552 27801twf.doc/d Fig. 9 is an enlarged view of the vicinity of the connecting portion shown in Fig. 6. Figure 10 is a schematic view of the first circular convex portion and the third circular concave portion shown in Figure 9. Figure 2 is a schematic view of an inner pin, a connecting portion and an outer pin according to a second embodiment of the present invention. Figure 12 is a schematic illustration of inner pins, connecting portions and outer pins in accordance with a third embodiment of the present invention. Fig. 13 is a view showing the inner lead, the connecting portion and the outer lead according to the fourth embodiment of the present invention. Figure 14 is a schematic illustration of internal pins, connections and outer leads in accordance with a fifth embodiment of the present invention. Figure 15 is a schematic illustration of an inner pin, a connecting portion and an outer 'pin according to a sixth embodiment of the present invention. • Figure 16 and Figure 17 are schematic diagrams of the remaining inner leads, connections, and outer leads shown in Figure 6. [Key Symbols] • la, 4〇, 4〇,: External pins lb, 36, 36': Inner pins lc, 38, 38': connection portion 2: notch 2a: inner edge 2b: joint portion 4, 6: electronic device 8: display panel

m J 13 1339552 27801lwf.doc/d 10 : printed circuit board 12 : driver IC 14 , 20 : flexible circuit board 16 , 18 : wire 22 : flexible film 24 : solder resistance layer 30 , 32 , 34 : group Group 42, 42': inner edge • 44, 44': outer edge 50: first rounded area 52: first rounded area 53: fourth rounded area. 54: second rounded area 55, 57: middle Zone 56: second rounded area 58: third rounded area • 59: fourth rounded area 60: third rounded area 62, 64: first edge 66, 68: second edge W1, W2: width Dl , D2 : Interval IU, R2: radius of curvature [S] 14

Claims (1)

27801twf.doc/d X. Application for Patent Park: 1. A flexible circuit board comprising: a flexible film; a plurality of inner leads disposed on the flexible film and each inner pin Having a first width; a plurality of outer pins disposed on the flexible film, each outer pin having a first width ′ and the second width being greater than the first width; and a plurality of connecting portions, each The connecting portion is connected to an outer pin corresponding to a corresponding one of the inner lead plates, and at least one of the plurality of connecting portions has an inner edge and an outer edge, wherein the outer edge has a first circular concave a second concave region and a first circular convex region between the first concave portion and the second concave portion, the inner edge having a second circular convex region, a first: circle = and a second concave region between the second circular convex region and the third circular convex region. 2. If the flexible clock diameter as described in the application for the 丨 丨 大于 大于 大于 大于 大于 第三 ^ ^ ^ ^ ^ ^ ^ ^ ^ 可 可 可 可 可 可 可 可 可 可 可 可 可 可 可 可 可 可 可Included in the first rounded area of the first rounded area is as follows. 5. 5. If the application is described in detail, the inner edge further includes the third concave area and the first;