TWI229577B - Flexible print circuit - Google Patents

Abstract

A flexible print circuit (FPC) suitable for loading at least an electronic component is described. The flexible print circuit at least comprises a first isolating layer, a patterned metal layer, a second isolating layer, and thermal through holes. The patterned metal layer is deposed on one surface of the first isolating layer, wherein the patterned metal layer has connection pads, and a pattern connecting to connection pads. Additionally, the second isolating layer deposed on the first isolating layer covers the patterned metal layer and second isolating layer has connection openings exposing partial area of the connection pads. The thermal through holes is located at the connection pads. The flexible print circuit comprises the thermal through holes so that the temperature of the connected pads and the electronic component can be reducing, then the reliability of the connection between the pads and the electronic component can be improved.

Description

1229577 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a flexible circuit board (f 1 exib 1 eprint circuit, FPC), and in particular to a method having a thermal through hole Flexible circuit board. [Prior technology] Traditional cathode ray displays (CRT) have the advantages of mature process technology and complete upstream, midstream, and downstream industries. Among them, CRT displays use cathode ray discharge to generate images. Cathode rays can cause potential impact on the eyes, so liquid crystal displays (LCD), organic light emitting displays (0LED), or plasma display panels (PDP) have the advantages of low power consumption, low radiation, and high display quality. Has gradually become the mainstream of display products. For liquid crystal display (transm type), it is necessary to make the flexible display (reflec i ss i ve LCD) through the connection of the liquid crystal substrate and the module by the cathode tube on the board. The transflective panel and the backlight are arranged on two transparent tube cover, light source or light-emitting diode flexible circuit board described by the light-emitting diode. Since the circuit board and the light-emitting, the light ti ve LCD and the half-transmission half The reflective module is composed of a light-emitting diode and a light-emitting diode element constructed between the substrate and the light guide plate element array, and a transmissive liquid crystal transflective liquid crystal liquid crystal display. The liquid crystal layer of the liquid crystal panel system Structure ~ structure, in the light 0 column, the temperature of the light emitting diode = polar element system and the component produced by the element rises. It is divided into three reflective display monitors as an example. The main is composed of two transparent lenses and the backlight. Sources such as cold body elements generate heat through soft circuits and are therefore connected

1229577 V. Description of the invention (2) The connection between the pad and the light-emitting diode element is liable to be deteriorated due to high temperature, which causes the light-emitting diode element to fail. In addition, other electronic components arranged on the flexible circuit board will also cause the performance of other electronic components to decrease due to the temperature rise of the flexible circuit board. [Summary of the Invention] In view of this, the object of the present invention is to provide a flexible circuit board with thermally conductive through holes to reduce the temperature of the connection pad and the electronic component, thereby improving the reliability of the connection between the electronic component and the connection pad. Based on the above or other objectives, the present invention provides a flexible circuit board, which is suitable for carrying at least one electronic component. The flexible circuit board includes, for example, a first insulating layer, a patterned metal layer, and a second insulating layer. The first insulating layer has a first surface and a second surface corresponding to the first surface. In addition, the patterned metal layer is disposed on the first surface of the first insulating layer, and the patterned metal layer includes, for example, a plurality of connection pads and a pattern line connected to the connection pads. In addition, the second insulation layer is disposed on the first surface of the first insulation layer and covers the patterned metal layer. The second insulation layer has a plurality of connection openings to expose a part of the connection pads. The insulation layer and the patterned metal layer have, for example, a plurality of first thermal vias, and the first thermal vias are located at the positions where the connection pads are located. According to the flexible circuit board according to the preferred embodiment of the present invention, the patterned metal layer further includes, for example, a plurality of first heat dissipation pads, and the first heat dissipation pads are disposed on the first surface of the first insulation layer, and each A first heat dissipation pad is connected to one of the connection pads. In the flexible circuit board of the present invention, the first insulating layer, the patterned metal layer, and the second insulating layer further include, for example, a plurality of first insulating layers.

12400twf.ptd Page 9 1229577 V. Description of the invention (3) Two thermally conductive through holes, and these second thermally conductive through holes are located at the position of the first heat dissipation pad to increase the heat dissipation efficiency of the first heat dissipation pad. According to the flexible circuit board according to the preferred embodiment of the present invention, the patterned metal layer further includes, for example, a patterned second heat dissipation pad, and the patterned second heat dissipation pad is disposed on the first of the first insulating layer. On the surface, a part of the patterned second heat dissipation pad is located under the electronic component. In the flexible circuit board of the present invention, the first insulating layer, the patterned metal layer, and the second insulating layer further include a plurality of third thermal vias, and the third thermal vias are located on the patterned second heat dissipation pad. Location. The flexible circuit board according to the preferred embodiment of the present invention, for example, further includes a heat dissipation metal film, and the heat dissipation metal film is disposed on the second surface of the first insulating layer to improve the heat dissipation efficiency of the flexible circuit board. Based on the foregoing or other objectives, the present invention proposes another flexible circuit board, which is suitable for carrying at least one electronic component. The flexible circuit board includes, for example, a first insulating layer, a patterned metal layer, and a second insulating layer. The first insulating layer has a first surface and a second surface corresponding to the first surface. In addition, the patterned metal layer is disposed on the first surface of the first insulating layer. The patterned metal layer includes, for example, a plurality of connection pads, a plurality of first heat dissipation pads, and a pattern line connected to the connection pads. The first heat radiation pad is connected to one of the connection pads. In addition, the second insulation layer is disposed on the first surface of the first insulation layer and covers the patterned metal layer. The second insulation layer has a plurality of connection openings to expose a part of the connection pad. According to the flexible circuit board according to the preferred embodiment of the present invention,

12400twf.ptd Page 10 1229577 V. Description of the invention (4) An insulating layer, a patterned metal layer, and a second insulating layer, for example, have a plurality of second thermal vias, and these second thermal vias are located on the first heat dissipation pad Is located to increase the heat dissipation area of the first heat sink. According to the flexible circuit board according to the preferred embodiment of the present invention, the patterned metal layer further includes, for example, a patterned second thermal pad, and the patterned second thermal pad is disposed on the first of the first insulating layer. On the surface, a part of the patterned second heat dissipation pad is located under the electronic component. In addition, the first insulating layer, the patterned metal layer, and the second insulating layer of the flexible circuit board of the present invention have, for example, a plurality of third thermal vias, and these second thermal vias are located on the patterned second heat dissipation pad. s position. The flexible circuit board according to a preferred embodiment of the present invention, for example, further includes a heat dissipation metal film, and the heat dissipation metal film is disposed on the second surface of the first insulating layer. Based on the foregoing or other objectives, the present invention proposes another flexible circuit, which is suitable for carrying at least one electronic component, and the flexible circuit board includes, for example, a first insulating layer, a patterned metal layer, a second insulating layer, and a heat-dissipating metal. membrane. The first insulating layer has a first surface and a second surface corresponding to the first surface. In addition, the patterned metal layer is disposed on the first surface of the first insulating layer, and the patterned metal layer includes, for example, a plurality of connection pads and a pattern line connected to the connection pads. In addition, the second insulating layer is disposed on the first surface of the first insulating layer and covers the patterned metal layer, and the second insulating layer has a plurality of connection openings to expose a part of the connection pad and the heat-dissipating metal. The film is arranged on the second surface of the first insulating layer.

12400twf.ptd Page 11 1229577 V. Description of the invention (5) According to the flexible circuit board according to the preferred embodiment of the present invention, the patterned metal layer further includes a plurality of first heat dissipation pads, and the first heat dissipation pads are It is disposed on the first surface of the first insulating layer, and each first heat dissipation pad is connected to one of the connection pads. In the flexible circuit board of the present invention, the first insulating layer, the patterned metal layer, the second insulating layer, and the heat-dissipating metal film have, for example, a plurality of second heat-conducting through holes, and the second heat-conducting through-holes are located at the first heat-dissipating hole. Location. According to the flexible circuit board according to the preferred embodiment of the present invention, the patterned metal layer further includes, for example, a patterned second heat dissipation pad, and the patterned second heat dissipation pad is disposed on the first insulating layer. On the surface, a part of the patterned second heat dissipation pad is located under the electronic component. In the flexible circuit board of the present invention, the first insulating layer, the patterned metal layer, the second insulating layer, and the heat-dissipating metal film have, for example, a plurality of third heat-conducting through holes, and these second heat-conducting through-holes are located in the patterned first hole. Where the two cooling pads are located. Based on the above, the flexible circuit board of the present invention has a plurality of thermally conductive through holes, and these thermally conductive through holes correspond to the connection pads. In addition, the flexible circuit board of the present invention may also have a first heat-dissipating pad or a patterned second heat-dissipating pad, and the connection pad and the electronic component may discharge part of the heat energy to the first heat-dissipating pad or the patterned second heat-dissipating pad. The outside world further improves the reliability of the connection between the electronic component and the connection pad. The aforementioned thermal vias and the first thermal pad or the thermal vias and the patterned second thermal pad can also be used in combination to increase the heat dissipation area of the first thermal pad or the patterned second thermal pad. Furthermore, the flexible circuit board of the present invention is disposed on the second surface of the first insulating layer by a heat-dissipating metal film to increase the heat dissipation efficiency of the flexible circuit board.

12400twf.ptd Page 12 1229577 V. Description of the invention (6) In order to make the meaning of the present invention easier to understand, the following t-track and other purposes, features and advantages can be more clearly explained as follows. The best embodiment of the cattle is described in detail in conjunction with the attached drawings. [Embodiment] Please refer to Fig. 1 for an example. The cross-section edge of the flexible circuit board shows the first preferred embodiment of the present invention. One embodiment carries at least one electron 7K imaginary map. The flexible circuit board 100 according to the present invention is suitable for 100 connections, and the electronic components 200 are connected to the electronic components 2 0 0 and the flexible circuit boards are separated from each other, such as the light emitting diode 2 The polar element or the organic electromagnet m ^ ^, the m ^ circuit board 100 includes, for example, a first insulating layer 110, a patterned metal layer 120, and a substrate 124a. Basin—The second insulating layer 130 and the plurality of first heat-conducting through holes. The insulating layer 110 has a first surface 112a and a second surface 112b opposite to the surface 112a, and the first insulating layer 110 is transparent. For example, it is plyimide or other transparent insulation. The patterned metal layer 1 2 0 is disposed on the first table f of the first insulating layer 1 10, and the patterned metal layer 1 2 0 includes, for example, a plurality of connection pads 1 2Λ and “a pattern of one of these connection 塾 124 connections”. Circuit 122, and the material of the patterned metal layer 120 is, for example, copper, or other conductive materials with good conductive and thermal conductivity characteristics. In addition, the 'electronic component 2000' is connected to the flexible circuit board 1 00's connection pad 1 24. 'The first thermal vias 2 and 4 a are located at the positions where the connection pads 124 are located.' And the first thermal vias 124 a can increase the heat dissipation area of the connection pads 124, thereby reducing the temperature of the connection pads 124 and the electronic components 200. Please refer to FIG. 1 again. The second insulating layer 130 is disposed on the first surface 112a of the first insulating layer 110 and covers the patterned metal layer 120. Its

12400twf.ptd Page 13 1229577 --- In the-1 3 2 a ~ yi Yi margin layer 1 3 〇 has a plurality of connection openings 1 3 2 'to expose the connection 塾 醯 imine ^ sub-region, and the second The material of the insulating layer 1 3 0 is, for example, a transparent poly secondary (PO 1 yimi de) or other transparent insulating material. In this embodiment, the water-gas-gas insulation layer 130 can protect the patterned metal layer 120 from external force. —Disperse: Referring to FIG. 1 again, the flexible circuit board 1 0 0 of this embodiment may further include a surface i 1 & a metal film 1 4 0, and it is arranged in the second surface of the first insulating layer 丨 丨 〇 It is made of gold, and the material of the heat-dissipating metal film 140 is copper or aluminum. It is worth mentioning that the second embodiment of the present invention has a heat-dissipating metal film 1 4 0. Therefore, this embodiment and the following embodiments may or may not have a heat-dissipating metal film 140, and can also achieve the purpose of the present invention. + Generally speaking The smaller the hole diameter of the heat-conducting through hole 1 2 4 a, the lower the thermal resistance. The smaller the hole diameter of the heat-conducting through hole 3, the better the heat dissipation efficiency. The minimum hole diameter of the upper three heat-conducting through holes 1 2 4 a is, for example, 10 to 12 mils (mi 1 'If the hole diameter of the heat-conducting through-holes 12 4a is designed to be 5 to 6 mils, thermal injection processing In addition, according to this embodiment, it can be known that the connection 24 also has a heat dissipation function, so this embodiment also contacts the area of the outside to increase the heat dissipation efficiency. I will not repeat the connection 124 in detail here. Referring to FIG. 2, a schematic top view of a flexible circuit board according to a second preferred embodiment of the present invention is shown. This embodiment is similar to the first embodiment, and the difference is that this embodiment has a first heat sink. 12β, and the first heat dissipation pad 1 2 6 is connected to the connection pad 1 2 4 to increase the overall heat dissipation surface

12400twf.ptd Page 14 1229577 V. Description of the invention (8) The material of the first heat dissipation pad 126 is, for example, steel, aluminum, or other materials with good electrical and thermal conductivity. Therefore, the connection pin will be able to conduct to the first heat sink 126 'and to the outside via the first heat sink 126 P / to reduce the temperature of the connection pad 124. The third embodiment of the present invention is a three-dimensional drawing of the present invention [preferred implementation {column < a car deficient circuit board; Figure f, please refer to Figures 1 and 3 at the same time, this embodiment The difference from ^ is that the soft circuit of this embodiment is located at the first and second thermally conductive vias 126a, and the second thermally conductive vias 126a pass through the locations where the pads 126 are located, where The second heat-conducting through-hole 126a is added to the scattered gold mi / 0, the patterned metal layer 120, and the second insulating layer 130. The first film 14 is added. Therefore, the above-mentioned second heat-conducting through-hole 126a can also dissipate the heat dissipation area of the heat sink 126, thereby increasing the first heat dissipation pad 126 'to achieve the purpose of the present invention. FIG. 4 is a schematic plan view of a fourth preferred embodiment of the present invention except for a difference plate. This embodiment is similar to the first embodiment, 1 2 8 ', and the eighth point is that this embodiment has a patterned second heat sink below, and the "patterned second heat sink 128" is located The material of other patterned second heat dissipation pads 128 of the electronic component 200 is, for example, copper, aluminum, or a material with good thermal conductivity. Due to the operation of the electronic component 200, thermal energy, if the thermal design of the electronic component 2000 is poor, the electronic component 2000 may have a shorter service life. Therefore, in this embodiment, the electronic element conducts the heat energy of ° 卩 to the patterned second heat sink 塾 128 to reduce

Page 15 1229577

Low self temperature resets you to implement, thereby increasing the life of the component itself. FIG. 5 is a schematic top view of a flexible circuit board according to a fifth preferred embodiment of the present invention. Please refer to FIG. 丨, FIG. 4 and FIG. 5 at the same time. This embodiment is similar to the fourth embodiment. In order to improve the heat dissipation efficiency of the patterned second heat sink 128, this embodiment is based on the patterned second heat sink. A plurality of third thermal vias 128a are designed at the position of the pad 2′8, and the third thermal vias 1283 pass through the first insulating layer 1 1 0, the patterned metal layer 1 2 0, the second insulating layer 130 and Thermal metal film 4o. Since the third heat-conducting through-hole 128a can greatly increase the heat dissipation area of the patterned second heat-dissipating pad 128, the third heat-conducting through-hole 128a can increase the heat dissipation efficiency of the patterned second heat-dissipating pad 128 to achieve the present invention. Purpose.

% A Please refer to FIG. 6, which illustrates a schematic top view of a flexible circuit board according to a sixth preferred embodiment of the present invention. This embodiment has a first heat sink 126, which is instead connected to the connection pad 124 to increase the overall heat dissipation area. When the electronic component 2000 is in operation, the heat generated by the driving current entering the electronic component 200 through the connection pad 124 can be conducted to the outside through the first heat dissipation pad 126 and the connection pad 124. Therefore, this embodiment can effectively reduce the temperature of the connection 塾 124 and the electronic component 200, and avoid the failure of the electronic component 200. Seventh Please refer to FIG. 7, which illustrates a schematic top view of a flexible circuit board according to a seventh preferred embodiment of the present invention. As can be seen from the sixth embodiment of the present invention, the larger the heat radiation area, the more difficult it is for the temperature to rise. Therefore, in this embodiment

12400twf.ptd

1229577 V. In the description of the invention (10), a plurality of second heat-conducting through holes 126a are designed at the positions of the first heat-dissipating pads 1 2 6 to increase the heat-dissipating area of the first heat-dissipating 塾 ΐ2β. Compared with the conventional flexible circuit board, this embodiment has a better heat dissipation effect, and can further reduce the temperature of the electronic component 200 and the connection pad 124 to reduce the possibility of the electronic component 200 failure. Eighth Embodiment FIG. 8 is a schematic top view of a flexible circuit board according to an eighth preferred embodiment of the present invention. Please refer to FIG. 1 and FIG. 8 at the same time. Since the electronic component 200 operates, thermal energy is generated, which causes the temperature of the overlapping area of the second insulating layer 13 and the electronic component 200 to rise. It has a patterned second heat dissipation pad 128, and a part of the patterned second heat dissipation pad 128 is located below the electronic component 2000, and the material of the patterned second heat dissipation pad 1 f 8 is copper, aluminum, or other conductive materials. 2. Material with good thermal conductivity. The thermal energy generated by the aforementioned electronic component 2000 can be discharged to the outside through the patterned first heat sink 128. Therefore, in addition to increasing the overall heat dissipation efficiency, the patterned second heat dissipation pad 128 can reduce the temperature of the overlapping area of the second insulation layer 300 and the electronic component 200. "Ninth implementation you 丨 Fig. 9 shows a schematic top view of a flexible circuit board according to the ninth preferred embodiment of the present invention. Please refer to Fig. 9. This embodiment is similar to the eighth embodiment. The only difference is that: This embodiment has a plurality of third thermally conductive vias 128a, and these second thermally conductive vias 128a are located at the position of the patterned second thermal pad lj 8, and the third thermally conductive vias 2a can increase the patterning The contact area of the first heat radiation pad 128 with the air, in other words, the third heat conduction

1229577 V. Description of the invention (11) The hole 128a can increase the heat dissipation area of the patterned second heat sink 128, so the patterned second heat sink 1 2 8 can quickly discharge the heat energy to the outside. In addition, the flexible circuit board 100 of the present invention may have both the first heat dissipation pad 126 and the patterned second heat dissipation pad 128, and may also be separately connected to the connection pad 124, the first heat dissipation pad 126, and the patterned second heat dissipation pad. Designing the first thermal via 124a, the second thermal via 126a, and the third thermal via 1128a at the position of the pad 128 can also achieve the purpose of the present invention, and details are not described herein again. In summary, the flexible circuit board of the present invention has the following advantages: 1. The flexible circuit board of the present invention has a plurality of thermally conductive through holes, and the thermally conductive through holes correspond to the connection pads, and the thermally conductive through holes increase the connection pads to contact the air. Area, the thermally conductive via can improve the heat dissipation efficiency of the flexible circuit board of the present invention. The flexible circuit board of the present invention can also have a first heat dissipation pad or a patterned second heat dissipation pad, and the connection pad and the electronic component can Part of the thermal energy is conducted to the first heat dissipation pad or the patterned second heat dissipation pad to reduce the temperature of the connection pad and the electronic component. In addition to improving the reliability of the connection between the electronic component and the connection pad, it also increases the service life of the electronic component itself. 3. In the flexible circuit board of the present invention, a plurality of thermally conductive through holes can be designed on the first heat radiation pad or the patterned second heat radiation pad to increase the heat radiation efficiency of the first heat radiation pad or the patterned second heat radiation. 4. The flexible circuit board of the present invention further includes a heat-dissipating metal film, which is disposed on the second surface of the first insulating layer, so that the flexible circuit board of the present invention has better heat dissipation efficiency. 5. The flexible circuit board of the present invention is not limited to a single-layer pattern

12400twf.ptd Page 18 1229577 V. Description of the Invention (12) The metalized layer can be applied to multiple patterned metal layers. Although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application.

12400twf.ptd Page 19 1229577 Brief Description of Drawings Figure 1 shows a schematic cross-sectional view of a flexible circuit board according to the first preferred embodiment of the present invention. FIG. 2 is a schematic top view of a heat dissipation structure according to a second preferred embodiment of the present invention. FIG. 3 is a schematic top view of a heat dissipation structure according to a third preferred embodiment of the present invention. FIG. 4 is a schematic top view of a heat dissipation structure according to a fourth preferred embodiment of the present invention. FIG. 5 is a schematic top view of a heat dissipation structure according to a fifth preferred embodiment of the present invention. FIG. 6 is a schematic top view of a heat dissipation structure according to a sixth preferred embodiment of the present invention. FIG. 7 is a schematic top view of a heat dissipation structure according to a seventh preferred embodiment of the present invention. FIG. 8 is a schematic top view of a heat dissipation structure according to an eighth preferred embodiment of the present invention. FIG. 9 is a schematic top view of a heat dissipation structure according to a ninth preferred embodiment of the present invention. [Illustration of Graphical Symbols] 1 0 0: flexible circuit board 1 1 0: first insulating layer 112a: first surface 1 1 2b: second surface 1 2 0: patterned metal layer

12400twf.ptd Page 20 1229577 Brief description of the drawings 1 2 2: Pattern line 1 2 4: Connection pad 124 a: First thermal via 1 2 6: First thermal pad 1 2 6 a: Second thermal via 128: Patterned second heat dissipation pad 128a: third thermal via 1 3 0: second insulating layer 1 3 2: connection opening 140: heat dissipation metal film 2 0 0: electronic component

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Claims (1)

1229577 VI. Scope of patent application 1. A flexible circuit board adapted to carry at least one electronic component, the flexible circuit board includes at least: a first insulating layer having a first surface and a second surface corresponding to the first surface A surface; a patterned metal layer disposed on the first surface of the first insulation layer, wherein the patterned metal layer includes a plurality of connection pads and a pattern line connected to the connection pads; and a second insulation A layer disposed on the first surface of the first insulation layer and covering the patterned metal layer, wherein the second insulation layer has a plurality of connection openings to expose a part of the connection pads, and the The first insulating layer and the patterned metal layer include a plurality of first thermal vias, and the first thermal vias are located at the positions where the connection pads are located. 2. The flexible circuit board according to item 1 of the scope of patent application, wherein the patterned metal layer further includes a plurality of first heat dissipation pads, which are disposed on the first surface of the first insulation layer, and each of these The first heat radiation pad is connected to one of the connection pads. 3. The flexible circuit board according to item 2 of the scope of patent application, wherein the first insulating layer, the patterned metal layer, and the second insulating layer include a plurality of second thermally conductive vias, and the second thermally conductive vias It is located at the position where the first heat dissipation pads are located. 4. The flexible circuit board according to item 1 of the scope of patent application, wherein the patterned metal layer further includes a patterned second heat dissipation pad disposed on the first surface of the first insulation layer, and the pattern A part of the second heat dissipation pad is located under the electronic component. 12400twf.ptd Page 22 1229577 6. Patent application scope 5. The flexible circuit board as described in item 4 of the patent application scope, wherein the first insulation layer, the patterned metal layer and the second insulation layer include a plurality of first There are three thermally conductive through holes, and the second thermally conductive through holes are located at the position where the patterned second heat dissipation pad is located. 6. The flexible circuit board according to item 1 of the scope of patent application, further comprising a heat dissipation metal film disposed on the second surface of the first insulating layer. 7-A flexible circuit board adapted to carry at least one electronic component, the flexible circuit board includes at least: a first insulating layer having a first surface and a second surface corresponding to the first surface; a patterning A metal layer is disposed on the first surface of the first insulation layer. The patterned metal layer includes a plurality of connection pads, a plurality of first heat dissipation pads, and a pattern line connected to the connection pads. The first heat dissipation pads are connected to one of the connection pads; and a second insulation layer is disposed on the first surface of the first insulation layer and covers the patterned metal layer, wherein the first The two insulating layers have a plurality of connection openings to expose a part of the connection pads. 8. The flexible circuit board according to item 7 of the scope of patent application, wherein the first insulating layer, the patterned metal layer, and the second insulating layer include a plurality of second thermally conductive vias, and the second thermally conductive vias It is located at the position where the first heat dissipation pads are located. 9. The flexible circuit board according to item 7 of the scope of patent application, wherein the patterned metal layer further includes a patterned second heat dissipation pad disposed on the first surface of the first insulation layer, and the pattern Part of the second heat sink 12400twf.ptd Page 23 1229577 6. Scope of patent application Sub-area is located under the electronic component. 10. The flexible circuit board according to item 9 of the scope of patent application, wherein the first insulating layer, the patterned metal layer, and the second insulating layer include a plurality of third thermally conductive vias, and the second thermally conductive vias The hole is located at the position where the patterned second heat dissipation pad is located. 1 1. The flexible circuit board according to item 7 of the scope of patent application, further comprising a heat-dissipating metal film disposed on the second surface of the first insulating layer. 1 2. A flexible circuit board adapted to carry at least one electronic component, the flexible circuit board includes at least: a first insulating layer having a first surface and a second surface corresponding to the first surface; a pattern A metallized layer is disposed on the first surface of the first insulation layer, wherein the patterned metal layer includes a plurality of connection pads and a pattern line connected to the connection pads; a second insulation layer is disposed on the On the first surface of the first insulating layer and covering the patterned metal layer, wherein the second insulating layer has a plurality of connection openings to expose a part of the connection pads; and a heat-dissipating metal film, configured On the second surface of the first insulating layer. 1 3. The flexible circuit board according to item 12 of the scope of patent application, wherein the patterned metal layer further includes a plurality of first heat dissipation pads disposed on the first surface of the first insulation layer, and each The first heat dissipation pads are connected to one of the connection pads, and the first insulation layer, the patterned metal layer, the second insulation layer, and the heat dissipation metal film include a plurality of second heat conduction channels. 12400twf.ptd Page 24 1229577 6. Scope of patent application. The second thermally conductive through holes are located at the positions of the first heat dissipation pads. 1 4. The flexible circuit board according to item 12 of the scope of the patent application, wherein the patterned metal layer further includes a patterned second heat dissipation pad disposed on the first surface of the first insulating layer, and A part of the patterned second heat dissipation pad is located under the electronic component. 15. The flexible circuit board according to item 14 of the scope of patent application, wherein the first insulating layer, the patterned metal layer, the second insulating layer, and the heat-dissipating metal film include a plurality of third heat conducting channels. Holes, the second thermal vias are located at the position where the patterned second heat dissipation pad is located. 12400twf.ptd Page 25