200803678 * 〜〜一 了 16730twf.doc/006 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種印刷電路板及其製造方法，且特 別是有關於一種具有較高可靠性和較低生產成本的可撓式 電路板及其製造方法。 【先前技術】 印刷電路板（PCB)可存在多種不同類型。一些peg _ 為剛性的，例如那些具有由氧化銘或FR-4玻璃/環氧層壓 材料製成的基底的PCB，而其他的則相對可撓式（即，“可 撓式電路，），例如那些具有由聚亞醯胺、聚酯和類似物製 成的基底的PCB。 圖1是展示常規可撓式印刷電路板（FPC)的示意性 橫截面圖。請參看圖1，FPC100包括基底薄膜11〇、第一 黏接層120、第二黏接層13〇、第一導電層14〇、第二導電 ^ 15〇、苐一覆盍層16〇和第二覆蓋層。基底薄膜11〇 馨 ¥規地由可撓式薄膜（例如，聚亞醯胺樹脂、聚乙烯對苯 二甲酸酯（PET)和類似物）構成，且其具有第一表面u〇a 和第二表面ll〇b。第一導電層14〇和第二導電層15〇是具 有圖案化電路的銅箔，且其分別通過第一黏接層12〇和第 —黏接層130而黏接至基底薄膜n〇的第一表面u〇a和第 一表面110b。第一覆蓋層160和第二覆蓋層no是由（例 如）聚亞醯胺樹脂、PET和類似物構成的可撓式薄膜，以 便保護第一導電層140和第二導電層150。 圖2是展不將FPC連接至印刷電路板（pcB)的電連 5 200803678 JL 么 v/V/WA—Γ 16730twf.doc/006 接方法的示意圖。請參看圖2，首先提供上述FPC 100和 PCB 200。PCB 200在其表面上具有多個預焊錫膏 (pre-solder paste) 210，且預焊錫膏210可為無鉛焊料。 接著，使FPC 100的邊緣與PCB 200的邊緣重疊，且將FPC 100的跡線152置於PCB 200的相應預焊錫膏210上。接 著，通過熱把300對FPC 100施加壓力和熱以便使由銅箔 製成的跡線152和預焊錫膏210融化。最後，去除壓力和 熱以便形成電連接PCB 200和FPC 100的固體焊料接點。 此已知為“熱把回流（hot bar reflow) ”製程。為了有效 地回流焊料，熱把的溫度通常維持在約340〜400°C。然而， 黏接層120和130的耐熱溫度約為60〜70°C。因此，熱把 回流製程將破壞第二黏接層130，且跡線152不可牢固地 黏接至基底薄膜110。因此，FPC 100與PCB 200之間的 電連接的可靠性較低。 為了克服由熱把製程的較高操作溫度而導致的較低可 靠性問題，揭示了其他FPC以改進FPC與PCB之間的電 連接的可靠性。圖3是展示其他常規FPC的示意性橫截面 圖。請參看圖3，FPC 100,的結構類似於圖1中所展示的 FPC 100的結構。兩者間不同之處在於，在Fpc 1〇〇，中， 第一導電層140,和第二導電層150,分別直接安置於基底薄 膜110的上表面和下表面上。第一導電層14〇,和第二導電 層150’可通過層壓、沈積和類似方法而形成於基底薄膜 110上。一般而言，第一導電層14〇,和第二導電層150,通 過錢鍍而形成於基底薄膜上。因為第一導電層14〇，和 6 200803678 χ ^.νν^ν/^-τ 16730twf.doc/006 弟一導電層直接安置於基底溥膜110的上表面和下表 面上而沒有黏接層，所以可解決由熱把製程的較高操作溫 度而導致的FPC與PCB之間的電連接的較低可靠性問 題。然而，第一導電層14〇,和第二導電層15〇，通過濺鍍 而形成於基底薄膜110的一侧和另一側上，且因此將增加 FPC 100’的生產成本。 曰 因此，FPC技術中非常需要關於如何在顧及到可靠性 和成本的情況下提供一種新的FPC的解決方案。 【發明内容】 本發明針對於-種可承受熱把製程的操作溫度的可 撓式電路板^此，可改進所述可撓式電路板的可靠性。 、、本發明骑對於—種製造可撓式電路㈣方法， 減少可撓式電路板的生產成本。 如本文所體現且廣義上描述，本發明提供一種可 。所述可撓式電路板主要包括基底薄膜、第一 ^200803678 * 〜〜一16730twf.doc/006 IX. Description of the invention: [Technical field of invention] The present invention relates to a printed circuit board and a method of manufacturing the same, and in particular to a higher reliability and comparison Flexible circuit board with low production cost and its manufacturing method. [Prior Art] There are many different types of printed circuit boards (PCBs). Some peg _ are rigid, such as those with a substrate made of oxidized or FR-4 glass/epoxy laminate, while others are relatively flexible (ie, "flexible circuits,"). For example, those having a substrate made of polyimide, polyester, and the like. Figure 1 is a schematic cross-sectional view showing a conventional flexible printed circuit board (FPC). Referring to Figure 1, the FPC 100 includes a substrate. The film 11 , the first adhesive layer 120 , the second adhesive layer 13 , the first conductive layer 14 , the second conductive layer 15 , the first covering layer 16 , and the second covering layer. The fragrant film is composed of a flexible film (for example, polytheneamine resin, polyethylene terephthalate (PET), and the like), and has a first surface u〇a and a second surface 〇 b. The first conductive layer 14A and the second conductive layer 15A are copper foils having a patterned circuit, and are bonded to the base film n through the first adhesive layer 12 and the first adhesive layer 130, respectively. a first surface u〇a and a first surface 110b. The first cover layer 160 and the second cover layer no are made of, for example, polyamidamide resin A flexible film composed of PET and the like to protect the first conductive layer 140 and the second conductive layer 150. Fig. 2 is an electrical connection that does not connect the FPC to a printed circuit board (PCB) 5 200803678 JL v/V /WA—Γ16730twf.doc/006 Schematic diagram of the connection method. Referring to Fig. 2, the above FPC 100 and PCB 200 are first provided. The PCB 200 has a plurality of pre-solder pastes 210 on its surface, and The solder paste 210 can be a lead-free solder. Next, the edge of the FPC 100 is overlapped with the edge of the PCB 200, and the trace 152 of the FPC 100 is placed on the corresponding pre-solder paste 210 of the PCB 200. Next, 300 pairs of FPCs are passed through the heat. 100 applies pressure and heat to melt the traces 152 and pre-solder paste 210 made of copper foil. Finally, the pressure and heat are removed to form a solid solder joint electrically connecting the PCB 200 and the FPC 100. This is known as "hot" The hot bar reflow process is generally maintained at about 340 to 400 ° C in order to efficiently reflow the solder. However, the heat resistant temperatures of the adhesive layers 120 and 130 are about 60 to 70 ° C. The heat reflow process will destroy the second bonding layer 130, and the trace 152 It is not firmly adhered to the base film 110. Therefore, the reliability of the electrical connection between the FPC 100 and the PCB 200 is low. To overcome the problem of lower reliability caused by the higher operating temperature of the heat handling process, it is revealed Other FPCs are used to improve the reliability of the electrical connection between the FPC and the PCB. Figure 3 is a schematic cross-sectional view showing other conventional FPCs. Referring to Figure 3, the structure of the FPC 100 is similar to that of the FPC 100 shown in Figure 1. The difference between the two is that, in the Fpc 1 〇〇, the first conductive layer 140, and the second conductive layer 150 are directly disposed on the upper surface and the lower surface of the base film 110, respectively. The first conductive layer 14A, and the second conductive layer 150' may be formed on the base film 110 by lamination, deposition, and the like. In general, the first conductive layer 14A and the second conductive layer 150 are formed on the base film by money plating. Because the first conductive layer 14〇, and 6 200803678 χ ^.νν^ν/^-τ 16730twf.doc/006, a conductive layer is directly disposed on the upper surface and the lower surface of the base film 110 without an adhesive layer, Therefore, the problem of lower reliability of the electrical connection between the FPC and the PCB caused by the higher operating temperature of the process can be solved. However, the first conductive layer 14A, and the second conductive layer 15A are formed on one side and the other side of the base film 110 by sputtering, and thus the production cost of the FPC 100' will be increased.曰 Therefore, there is a great need in FPC technology to provide a new FPC solution with regard to reliability and cost. SUMMARY OF THE INVENTION The present invention is directed to a flexible circuit board that can withstand the operating temperature of a thermal handling process, and can improve the reliability of the flexible circuit board. The invention rides a method for manufacturing a flexible circuit (4) to reduce the production cost of the flexible circuit board. As embodied herein and broadly described, the invention provides a means. The flexible circuit board mainly comprises a base film, the first ^
i:::導:層ΐ黏接層。所基底薄膜具有第-表面和 述面卜34弟—導電層直接安置於所述基底薄膜的所 ’且具有熱接合區域。所述帛 於所述基底賴的所述第二表面上方 = 所述第二導電層與所述基底薄膜之間，乂;=接於 所述熱接合㊣域重疊。 料黏接層不與 安置的實闕，所述可撓式電路板進—步包括 女置於所述弟—導電層上 /匕栝 不與所述熱接麵域重疊。。所相—導電層 200803678 j. ^ν/ν/^ν/^-Γ 16730twf.doc/006 根據本發明的實施例，所述可撓式電路板進一步包括 女置於所述弟_導電層上的第二保護層。 口狀如本文所體現且廣義上描述，本發明還提供一種顯示 器裝置’其包括顯示面板、印刷電路板和上述可撓式電路 板。、所述印刷電路板安置於所述顯示面板的一侧。所述可 撓式電路板適且於電連接所述顯示面板與所述印刷電路 板0i:::guide: layer adhesive layer. The base film has a first surface and a surface-disposed conductive layer directly disposed on the base film and having a thermally bonded region. The 帛 is over the second surface of the substrate Between the second conductive layer and the base film, and is overlapped with the thermal bond. The adhesive layer does not overlap with the placement, and the flexible circuit board further includes a female on the conductive layer/匕栝 not overlapping the thermal interface. . Phase-conducting layer 200203678 j. ^ν/ν/^ν/^-Γ 16730twf.doc/006 According to an embodiment of the invention, the flexible circuit board further includes a female on the conductive layer The second protective layer. The mouthpiece is as embodied and broadly described herein, and the present invention also provides a display device' which includes a display panel, a printed circuit board, and the above flexible circuit board. The printed circuit board is disposed on one side of the display panel. The flexible circuit board is adapted to electrically connect the display panel and the printed circuit board.
帝如本文所體現且廣義上描述，本發明進一步提供一種 電子兀件，其包括上述顯示設備和輸人設備。所述輸入設 備適宜於為所軸示設備提供資訊，從續賴示設備顯 不圖像。 、如本文所體現且廣義上描述，本發明提供一種製造可 撓式電路㈣;η所述綠主要包括以下步驟 ，供基底賴，其上安置有第—導電層，其中所述第一導 電層具有熱接合區域。接著，提供第二導電層，其上安置 有黏接層。最後，用安置於所職底薄膜贿述第二導電 層之間的雜層將所述基底薄難所述第二導電層接合在 -起’且所述黏接層不與所述熱接合區域重疊。a σ 根據本發明的實施例，所述方法進一步 牛 驟：在將所述基底薄膜與所述第二導電層接合在—起^ 在所述第一導電層上形成第一保護層。 根據本發明的實施例，將所述第二導電層提供於保護 =間且將所述第二導電層安置於所述保護層與所述黏接 8 200803678 16730twf.doc/006 根據本發明的實齡】，通過沈積或層壓來形成安置於 所，基底薄膜上的所述第一導電層。更明確地說，通過賤 鍍來开 =成安置於所述基底薄膜上的所述第一導電層。 口 、综上所述，在本發明的可撓式電路板中，所述熱接合 區域上方不存在黏接層。因此，當執行熱接合製程（例如， 熱^回流製程）時’將不會有黏接層由於高操作溫度而被 破壞’且可改進可賦電路板與pCB之_電連接的可靠 鲁性。此外，與常規FPC相比，在本發明中，一個導電層通 過激鍍而形成於基底薄膜的一侧上，且另一導電層通過黏 接層而黏接至基底薄膜的另一侧。因此，可減少可撓式電 路板的生產成本。 ▲為讓本發明之上述和其他目的、特徵和優點能更明顯 易懂，下文特舉實施例，並配合所附圖式，作詳細說明如 下。 【實施方式】 _ 現將詳細參看本發明的當前優選實施例，附圖中對其 實例作出說明。任何可能的情況下，在附圖和具體實施方 式中使用相同參考標號來表示相同或相似零件。 圖4是展示根據本發明的一實施例的可撓式電路板的 示意性橫截面圖。請參看圖4，可撓式電路板400主要包 括基底薄膜410、第一導電層420、第二導電層430和黏接 層440。基底薄膜41〇具有第一表面41〇a和第二表面 410b ’且基底薄膜41〇由可撓式材料（例如，聚亞醯胺、 聚醋、聚乙烯對苯二曱酸酯（PET)和類似物）製成。第 9 200803678 rzuuDUZ4 16730twf.doc/006 -導電層420直接安置於基底薄膜的第一表面她 上’且具有適合熱接合製程的熱接合區域A，。在本 二實，例=第-導電層可為具有圖案化電路的銅 '泊。弟一導電層430安置於基底薄膜410的第二表面41〇b 上方’且其也可為具有圖案化電路的銅猪。第二導電層43〇 通過黏接層440而黏接至基底薄膜41〇，且第二導電^ _ 預先經随化從而使雜層物不無接合區域A，重疊。 • 第一保護層450選擇性地安置於第一導電層420 I用 於保護=-導電層420，且第-保護層45〇不與熱接合區 域A’重疊。類似地，第二保護層46〇選擇性地安置於第二 導電層430上用於保護第二導電層43〇。此外，一個或: 個以上導電插塞470選擇性地形成於基底薄膜41〇和黏接 層440中，用於電連接第一導電層42〇與第二導電層43〇。 圖5是展示通過使用熱接合製程將本發明的可撓式電 路板電連接至PCB的示意橫截面圖。通過使用熱接合製程 將可撓式電路板4〇〇與PCB 200接合在一起，且下文^熱 把回流製程作為實例來進行說明。請參看圖5，在本發明 的可撓式電路板400中，黏接層440不與熱接合區域A， 重豐。因此，當通過熱把300對可撓式電路板4〇〇的熱接 合區域A’施加壓力和熱以便使第一導電層42〇和pCB 2〇〇 的預知錫T 210融化時，將不會有安置于熱接合區域a， 上方的黏接層由於高操作溫度而被破壞。因此，可改進可 繞式電路板400與PCB 200之間的電連接的可靠性。 圖6A至圖6F是說明用於製造根據本發明的可撓式電 200803678 F2UU!>U24 1673〇twf.doc/006 路板的製程流程的示意性橫截面圖。首先，請參看圖6A， ，供基底薄膜410,其下表面上安置有第一導電層，且 第$$層42G具有熱接合區域A，。在本發明的一實施例 中’女置於基底薄膜410上的第一導電層42〇是通過沈積 ⑷如’濺鑛）或層壓而形成。接著，請參看圖6B，提供 第二導電層，其上具有黏接層44〇。最後，請參看圖 6C ’將基底薄膜41〇與第二導電層43〇接合在—起。黏接 • I 440安置於基底薄膜41〇與第二導電層之間，且黏 接層440不與熱接合區域八，重疊。至此，根據上述製程形 成了可撓式電路板的基本結構。 此外，請參看圖6E)，在將基底薄膜41〇與第二導電層 43(^接合在一起之前，所述方法可進一步包括以下步驟： 在第一導電層420上形成第一保護層45〇。第一保護層45〇 保護第一導電層420，且第一保護層45〇也暴露熱接 合區域A，。另外，請參看圖6E，可將圖6B中所展示的第 —導電層43〇提供於適於保護第二導電層430的第二保護 層460上，且將第二導電層43〇安置於第二保護層46〇與 黏接層440之間。然而，第一保護層450和第二保護層460 的製造次序在本發明中並不受限制。· —在本發明的一實施例中，可將圖0D中所展示的基底 薄膜410與圖6E中所展示的第二導電層430接合在一起 以形成圖6F中所展示的可撓式電路板4〇〇,。此外，一個 或一個以上導電插塞（未圖示）可形成於基底薄膜410和 黏接層440中，以便根據需要電連接第一導電層42〇與第 11 200803678 16730twf.doc/006 二導電層430。 立圖7疋展示匕s，述可撓式電路板的顯示器裝置的示 思圖。請參看圖7,顯示器裝置5〇〇主要包括 PCB 520和至少-個可繞式電路板53〇。顯示面板51〇可 為LCD顯示面板、電漿顯示面板或有機電致發光顯示面 板，且顯福板510的_在本發明巾並不受限制。㈣ 520安置於顯示面板510的―侧，且可撓式電路板53〇適 於電連接顯示面板510與PCB 52〇。可撓式電路板53〇盥 圖4中所展示的可撓式電路板相同，因此此處不再重複了 圖8是展示具有如圖7中所展示的顯示面板的電子元 件的示意性方框圖。請參看圖8，本發明的電子元件6〇〇 主要包括如圖7中所展示的顯示器裝置5〇〇和電連接至顯 示态裝置500的輸入设備61〇。圖7中展示了顯示器裝置 500的元件，因此此處不再重複。輸入設備61〇適於接收 用戶輸入的命令，並將命令傳輸至顯示器裝置5〇〇。 綜上所述，在可撓式電路板中，黏接層不與熱接合區 域重：。因此’當執行熱接合製程（例如，熱把回流製程） 時，將不會有黏接層由於高操作溫度而被破壞，且可改進 可撓式電路板與PCB之間的電連接的可靠性。此外，與常 規FPC相比，在本發明中，一個導電層通過濺鍍而形成於 基底薄膜的一侧上，且另一導電層通過黏接層而黏接至基 底薄膜的另一側。因此，可減少可撓式電路板的生產成本。 雖然本發明已以實施例揭露如上，然其並非用以限定 本發明，任何熟習此技藝者，在不脫離本發明之精神和範 12 200803678 16730twf.doc/006 圍内，當可作些許之更動與潤飾，因此本發明之保護範圍 當視後附之申請專利範圍所界定者為準。 【圖式簡單說明】 圖1是展示常規可撓式印刷電路板（FPC)的示意性 橫截面圖。 圖2是展示將FPC連接至印刷電路板（PCB)的電連 接方法的示意圖。 • 圖3是展示其他常規FPC的示意性橫截面圖。 一圖4是展示根據本發明的一實施例的可撓式電路板的 示意性橫截面圖。 圖5是展示通過使用熱把回流製程將本發明的可撓式 電路板電連接至PCB的示意性橫截面圖。 圖6A至圖6F是說明用於製造根據本發明的可撓式電 路板的製程流程的示意性橫截面圖。 圖7是展示包含上述可撓式電路板的顯示器裝置的示 赢 意圖。 圖8是展不具有如圖7中所展示的顯示面板的電子元 件的示意性方框圖。 【主要元件符號說明】 100、100’ ：可撓式印刷電路板 110、410 :基底薄膜 110a、110b、410a、41〇b :表面 120、130、440 :黏接層 140、150、140,、150’、420、430 :導電層 13 200803678 rzuu^uz4 16730twf.doc/006 152 :跡線 160、170 :覆蓋層 200、520 :印刷電路板 210 :預焊錫膏 300 :熱把 400、530 :可撓式電路板 450、460 :保護層 470 :導電插塞 500 :顯示器裝置 510 :顯示面板 600 :電子元件 610 :輸入設備 A’ ：熱接合區域As embodied and broadly described herein, the present invention further provides an electronic component comprising the above display device and input device. The input device is adapted to provide information to the axis-displayed device and to display an image from the device. As embodied and broadly described herein, the present invention provides a method of fabricating a flexible circuit (4); η said green mainly includes the following steps for a substrate, on which a first conductive layer is disposed, wherein the first conductive layer Has a hot junction area. Next, a second conductive layer is provided on which an adhesive layer is disposed. Finally, the substrate is made thin by the impurity layer disposed between the second conductive layer, and the second conductive layer is bonded to the substrate and the bonding layer is not bonded to the thermal bonding region. overlapping. a σ According to an embodiment of the present invention, the method further comprises: forming a first protective layer on the first conductive layer by bonding the base film and the second conductive layer. According to an embodiment of the present invention, the second conductive layer is provided in the protection=between and the second conductive layer is disposed on the protective layer and the bonding layer 200803678 16730twf.doc/006 Age, the first conductive layer disposed on the base film is formed by deposition or lamination. More specifically, the first conductive layer disposed on the base film is opened by ruthenium plating. In summary, in the flexible circuit board of the present invention, there is no adhesive layer above the thermal bonding region. Therefore, when the thermal bonding process (e.g., the thermal reflow process) is performed, "the bonding layer will not be broken due to the high operating temperature" and the reliable lure of the electrical connection between the board and the pCB can be improved. Further, in the present invention, one conductive layer is formed on one side of the base film by laser plating, and the other conductive layer is bonded to the other side of the base film through the adhesive layer, as compared with the conventional FPC. Therefore, the production cost of the flexible circuit board can be reduced. The above and other objects, features, and advantages of the present invention will become more apparent from the aspects of the appended claims. [Embodiment] _ The presently preferred embodiments of the present invention will now be described in detail, and examples thereof are illustrated in the accompanying drawings. Wherever possible, the same reference numerals are used in the FIGS. 4 is a schematic cross-sectional view showing a flexible circuit board in accordance with an embodiment of the present invention. Referring to FIG. 4, the flexible circuit board 400 mainly includes a base film 410, a first conductive layer 420, a second conductive layer 430, and an adhesive layer 440. The base film 41 has a first surface 41A and a second surface 410b' and the base film 41 is made of a flexible material (for example, polyamido, polyester, polyethylene terephthalate (PET), and Made of analogs). No. 9 200803678 rzuuDUZ4 16730twf.doc/006 - The conductive layer 420 is disposed directly on the first surface of the base film and has a thermal joint region A suitable for the thermal bonding process. In the second embodiment, the example = the first conductive layer may be a copper 'pod with a patterned circuit. A conductive layer 430 is disposed over the second surface 41〇b of the base film 410 and may also be a copper pig having a patterned circuit. The second conductive layer 43 is adhered to the base film 41 by the adhesive layer 440, and the second conductive layer is preliminarily subjected to the bonding so that the impurity layer is overlapped without the bonding region A. • The first protective layer 450 is selectively disposed on the first conductive layer 420 I for protecting the conductive layer 420, and the first protective layer 45 is not overlapped with the thermal bonding region A'. Similarly, a second protective layer 46 is selectively disposed on the second conductive layer 430 for protecting the second conductive layer 43A. In addition, one or more conductive plugs 470 are selectively formed in the base film 41A and the adhesive layer 440 for electrically connecting the first conductive layer 42A and the second conductive layer 43A. Figure 5 is a schematic cross-sectional view showing the electrical connection of the flexible circuit board of the present invention to a PCB by using a thermal bonding process. The flexible circuit board 4 is bonded to the PCB 200 by using a thermal bonding process, and the following is an example of the reflow process as an example. Referring to Fig. 5, in the flexible circuit board 400 of the present invention, the adhesive layer 440 is not heavy with the thermal junction region A. Therefore, when heat and pressure are applied to the thermal junction region A' of the flexible circuit board 4 by heat to melt the first conductive layer 42A and the pre-known tin T 210 of the pCB 2A, it will not There is an adhesive layer disposed above the thermal junction region a, which is destroyed due to high operating temperature. Therefore, the reliability of the electrical connection between the wraparound circuit board 400 and the PCB 200 can be improved. 6A through 6F are schematic cross-sectional views illustrating a process flow for fabricating a flexible electric 200803678 F2UU!> U24 1673〇twf.doc/006 circuit board in accordance with the present invention. First, referring to FIG. 6A, a base film 410 is disposed on a lower surface of which a first conductive layer is disposed, and a layer #20 has a thermally bonded region A. In an embodiment of the invention, the first conductive layer 42 is placed on the base film 410 by deposition (4) such as 'splashing' or lamination. Next, referring to Fig. 6B, a second conductive layer is provided having an adhesive layer 44A thereon. Finally, referring to Fig. 6C', the base film 41 is bonded to the second conductive layer 43. Bonding • I 440 is disposed between the base film 41〇 and the second conductive layer, and the adhesive layer 440 does not overlap with the thermal bonding region VIII. So far, the basic structure of the flexible circuit board has been formed according to the above process. In addition, referring to FIG. 6E), before the base film 41A and the second conductive layer 43 are bonded together, the method may further include the following steps: forming a first protective layer 45 on the first conductive layer 420. The first protective layer 45A protects the first conductive layer 420, and the first protective layer 45A also exposes the thermal bonding region A. In addition, referring to FIG. 6E, the first conductive layer 43 shown in FIG. 6B may be Provided on the second protective layer 460 adapted to protect the second conductive layer 430, and disposed between the second protective layer 46A and the adhesive layer 440. However, the first protective layer 450 and The manufacturing order of the second protective layer 460 is not limited in the present invention. In an embodiment of the present invention, the base film 410 shown in FIG. 0D and the second conductive layer shown in FIG. 6E can be used. The 430 are joined together to form the flexible circuit board 4 shown in Figure 6F. Additionally, one or more conductive plugs (not shown) may be formed in the base film 410 and the adhesive layer 440 so that Electrically connecting the first conductive layer 42〇 as needed and the 11th 200803678 16730twf.doc/0 06 Two conductive layers 430. Figure 7 shows a schematic diagram of a display device of a flexible circuit board. Referring to Figure 7, the display device 5 〇〇 mainly includes a PCB 520 and at least one wraparound circuit The display panel 51A may be an LCD display panel, a plasma display panel or an organic electroluminescence display panel, and the slab of the slab 510 is not limited in the invention. (4) 520 is disposed on the display panel 510. The side, and the flexible circuit board 53 is adapted to electrically connect the display panel 510 to the PCB 52. The flexible circuit board 53 is the same as the flexible circuit board shown in FIG. 4, and therefore is not repeated here. Figure 8 is a schematic block diagram showing electronic components having a display panel as shown in Figure 7. Referring to Figure 8, the electronic component 6A of the present invention primarily comprises a display device 5 as shown in Figure 7. And electrically connected to the input device 61 of the display device 500. The components of the display device 500 are shown in Figure 7, and therefore are not repeated here. The input device 61 is adapted to receive commands input by the user and transmit the commands to Display device 5〇〇. In a flexible circuit board, the bonding layer is not heavier than the thermal bonding area: therefore, when performing a thermal bonding process (for example, a thermal reflow process), there will be no adhesive layer due to high operating temperatures. Destroying and improving the reliability of the electrical connection between the flexible circuit board and the PCB. Further, in the present invention, a conductive layer is formed on one side of the base film by sputtering, as compared with the conventional FPC. And another conductive layer is adhered to the other side of the base film through the adhesive layer. Therefore, the production cost of the flexible circuit board can be reduced. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. The invention may be modified and modified by those skilled in the art without departing from the spirit of the invention and the scope of the invention. The definition is subject to change. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a conventional flexible printed circuit board (FPC). Fig. 2 is a schematic view showing an electrical connection method of connecting an FPC to a printed circuit board (PCB). • Figure 3 is a schematic cross-sectional view showing other conventional FPCs. Figure 4 is a schematic cross-sectional view showing a flexible circuit board in accordance with an embodiment of the present invention. Fig. 5 is a schematic cross-sectional view showing electrically connecting a flexible circuit board of the present invention to a PCB by using a heat reflow process. 6A to 6F are schematic cross-sectional views illustrating a process flow for manufacturing a flexible circuit board according to the present invention. Fig. 7 is a view showing the win of the display device including the above flexible circuit board. Figure 8 is a schematic block diagram showing an electronic component having no display panel as shown in Figure 7. [Main component symbol description] 100, 100': flexible printed circuit board 110, 410: base film 110a, 110b, 410a, 41〇b: surface 120, 130, 440: adhesive layer 140, 150, 140, 150', 420, 430: conductive layer 13 200803678 rzuu^uz4 16730twf.doc / 006 152: traces 160, 170: cover layer 200, 520: printed circuit board 210: pre-solder paste 300: heat handle 400, 530: Flexible circuit board 450, 460: protective layer 470: conductive plug 500: display device 510: display panel 600: electronic component 610: input device A': thermal bonding region