201008431 九、發明說明： 【發明所屬之技術領域】 本發明涉及電路板製作領域，尤其涉及一種柔性電路 ‘板之製作方法。 【先前技術】 柔性電路板通常由覆銅基材製成，其具有單面電路 板、雙面電路板及多層電路板之分。其中，單面電路板之 ❹製作工藝通常包括壓膜、曝光、顯影、蝕刻、鍍金等流程。 參見文獻：Traut，G.R; Rogers Corp.，CT; Manufacturing and integration techniques of microwave circuits; IEEE colloquium on，Page 4/1〜4/4;published on 10th Oct，1988 o 雙面電路板之製作還包括製作導通孔、電鍍導通孔等工 序。而多層電路板通常以層疊法製作，具體地，包括以下 步驟：第一步，以曝光、顯影、蝕刻工藝於覆銅基板表面 @形成導電線路；第二步，於導電線路之預定位置鑽貫通覆 銅基板之通孔；第三步，以電鍍工藝於通孔孔壁形成銅層， 從而形成導通孔，製得内層板；第四步，以另一覆銅基板 為外層基板，採用純膠將該外層基板壓合至内層板；第五 步，於外層基板之預定位置形成盲孔或通孔；第六步，以 電鍍工藝於盲孔或通孔孔壁形成銅層；第七步，採用曝光、 顯影、蝕刻工藝於外層基板表面形成導電線路，製得兩層 電路板，以該兩層電路板為内層基板，重復四步至第七步， 即可製得多層電路板。 201008431 為滿足電子產品輕、薄、小體積化之需要，柔性電路 ，板之導電線路需製作得越來越精細，尺寸需越來越小，這 要求採用越來越薄之覆銅基材作為原材料。但薄型覆銅基 材極易發生皺折，影響電路板製作，如於壓膜流程，由於 覆銅基材發生皺折，造成鋪設於覆銅基材之乾膜厚度不 一，進而引起後續製作之導電線路粗細不均，嚴重影響電 路板之品質。 ❹ 有鑑於此，提供一種能避免覆銅基材皺折之柔性電路 板之製作方法以確保線路製作品質實為必要。 【發明内容】 以下以實施例說明一種能避免覆銅基材皺折之柔性電 路板之製作方法。 、 該柔性電路板之製作方法包括以下步驟：提供補強板 及覆銅基材，該補強板包括基材層及設於該基材層表面之 ©黏膠層，該覆銅基材包括絕緣層及設於該絕緣層表面之導 電層；將該覆銅基材黏附於該補強板並使該導電層露出； 於該導電層内形成導電線路，製得電路基板；分離補強板 與電路基板。 與先前技術相比，本技術方案之柔性電路板之製作方 法於製作導電線路前採用補強板貼合覆銅基材，使得覆銅 基材之厚度增加，從而避免了於製作電路板之過程中覆銅 基材發生皺折，進而提高了電路板製作精度。該製作方法 操作簡單，於完成電路板製作後僅需將補強板與電路板分 201008431 離即可。 【實施方式】 X下將、實施例及附圖對本技術方案提供之柔性電 路板之製作方法進行詳細說明。 該柔性電路板之製作方法包括以下步驟： 第步，提供補強板10及覆銅基材20。 ❹ 請參見圖1，本實施例採用之補強板U)包括-基材層 11及分別設於基材層u之相對兩表面之兩黏膠層12。該 兩黏㈣ί2於後續製程中用於黏附覆銅基材2G。基材層 11材質優選具有較大拉伸強度及彎曲強度，吸濕性、㈣ 性、尺寸穩定性及化學穩定性優異之塑膠，如聚酿亞胺、 聚乙烯萘、聚對苯二曱酸乙二醇醋或本領域常用之其他樹 脂。黏膠層12可由熱塑性膠黏劑或紫外光固化膠黏劑製 成’其黏接力以後續能人I將電路基板與黏膠層12剝離為 ❹宜。優選地’基材層11之厚度介於8微米至1〇〇微米之間， 黏膠層12之厚度介於8微米至50微米之間，其黏接力介 於 0.8~8gf/cm 〇 當然，補強板10並不限於上述結構，例如其可由一基 材層及一黏膠層組成，或由一黏膠層及一基材層相互交替 層疊而成，但其至少一外層為黏膠層。此外，為阻擋灰塵 進入黏膠層以及便於儲存，補強板可進一步包括黏附於黏 膠層表面之保護層。 21 —表面 覆銅基材20包括絕緣層21及設置於絕緣層 7 201008431 ，即第一表面 本實施例中， 第二表面211 之導電層22。覆銅基材2〇具有相對兩表面 j21及與第一表面221相對之第二表面211。 第一表面221對應於導電層22之—外表面， 對應於絕緣層21之一外表面。 疏25 ’邑緣層21之材處可選自柔韌性較好之塑膠，如選自聚 =胺、聚四氣乙稀、聚硫胺、”基丙稀酸”旨、聚碳201008431 IX. Description of the Invention: [Technical Field] The present invention relates to the field of circuit board manufacturing, and more particularly to a flexible circuit ‘board manufacturing method. [Prior Art] A flexible circuit board is usually made of a copper-clad substrate having a single-sided circuit board, a double-sided circuit board, and a multilayer circuit board. Among them, the single-sided circuit board manufacturing process usually includes lamination, exposure, development, etching, gold plating and the like. See the literature: Traut, GR; Rogers Corp., CT; Manufacturing and integration techniques of microwave circuits; IEEE colloquium on, Page 4/1 to 4/4; published on 10th Oct, 1988 o Production of double-sided boards also includes production Conductive vias, plating vias, etc. The multi-layer circuit board is usually fabricated by a lamination method. Specifically, the method includes the following steps: first, forming a conductive line on the surface of the copper-clad substrate by exposure, development, and etching processes; and second, drilling through a predetermined position of the conductive line. The through hole of the copper-clad substrate; the third step, forming a copper layer on the wall of the through-hole by electroplating to form a via hole to obtain an inner layer; and fourth, using another copper-clad substrate as an outer substrate, using pure glue Pressing the outer substrate to the inner layer; in the fifth step, forming a blind hole or a through hole at a predetermined position of the outer substrate; in the sixth step, forming a copper layer on the blind hole or the through hole wall by an electroplating process; A conductive circuit is formed on the surface of the outer substrate by exposure, development, and etching processes to obtain a two-layer circuit board. The two-layer circuit board is used as an inner substrate, and four steps to the seventh step are repeated to form a multi-layer circuit board. 201008431 In order to meet the needs of light, thin and small-sized electronic products, flexible circuits and conductive lines of boards need to be made more and more fine, and the size needs to be smaller and smaller. This requires the use of increasingly thin copper-clad substrates. Raw materials. However, the thin copper-clad substrate is prone to wrinkles and affects the fabrication of the circuit board. For example, in the laminating process, the thickness of the dry film laid on the copper-clad substrate is different due to wrinkles of the copper-clad substrate, which leads to subsequent fabrication. The thickness of the conductive line is uneven, which seriously affects the quality of the circuit board. ❹ In view of this, it is necessary to provide a method of manufacturing a flexible circuit board that can avoid wrinkling of a copper-clad substrate to ensure the quality of the circuit fabrication. SUMMARY OF THE INVENTION A method of fabricating a flexible circuit board capable of avoiding wrinkling of a copper-clad substrate will be described below by way of examples. The manufacturing method of the flexible circuit board comprises the steps of: providing a reinforcing plate and a copper-clad substrate, the reinforcing plate comprising a substrate layer and an adhesive layer disposed on the surface of the substrate layer, the copper-clad substrate comprising an insulating layer And a conductive layer disposed on the surface of the insulating layer; the copper clad substrate is adhered to the reinforcing plate and the conductive layer is exposed; a conductive circuit is formed in the conductive layer to obtain a circuit substrate; and the reinforcing plate and the circuit substrate are separated. Compared with the prior art, the manufacturing method of the flexible circuit board of the present technical solution uses a reinforcing plate to bond the copper-clad substrate before the conductive circuit is formed, so that the thickness of the copper-clad substrate is increased, thereby avoiding the process of manufacturing the circuit board. The copper-clad substrate is wrinkled, which improves the precision of the board. The manufacturing method is simple in operation, and after the board is completed, only the reinforcing board and the circuit board need to be separated from 201008431. [Embodiment] The manufacturing method of the flexible circuit board provided by the present technical solution will be described in detail in the following, embodiments and drawings. The manufacturing method of the flexible circuit board comprises the following steps: In the first step, the reinforcing plate 10 and the copper-clad substrate 20 are provided. Referring to FIG. 1, the reinforcing plate U) used in the embodiment includes a base material layer 11 and two adhesive layers 12 respectively disposed on opposite surfaces of the base material layer u. The two-adhesive (four) ί2 is used to adhere the copper-clad substrate 2G in a subsequent process. The material of the base material layer 11 is preferably a plastic having a large tensile strength and bending strength, and having excellent hygroscopicity, (four) properties, dimensional stability, and chemical stability, such as polyacrylonitrile, polyethylene naphthalene, and polyterphenyl phthalic acid. Ethylene glycol vinegar or other resins commonly used in the art. The adhesive layer 12 can be made of a thermoplastic adhesive or an ultraviolet-curable adhesive, and its adhesive force can be used to peel off the circuit substrate and the adhesive layer 12 in a subsequent manner. Preferably, the thickness of the substrate layer 11 is between 8 micrometers and 1 micrometer, and the thickness of the adhesive layer 12 is between 8 micrometers and 50 micrometers, and the adhesion is between 0.8 and 8 gf/cm. The reinforcing plate 10 is not limited to the above structure. For example, it may be composed of a substrate layer and an adhesive layer, or an adhesive layer and a substrate layer may be alternately laminated, but at least one of the outer layers is an adhesive layer. Further, in order to block dust from entering the adhesive layer and to facilitate storage, the reinforcing plate may further include a protective layer adhered to the surface of the adhesive layer. 21 - Surface Copper-clad substrate 20 comprises an insulating layer 21 and a conductive layer 22 disposed on the insulating layer 7 201008431, i.e., the first surface in this embodiment, the second surface 211. The copper clad substrate 2 has two opposite surfaces j21 and a second surface 211 opposite to the first surface 221. The first surface 221 corresponds to the outer surface of the conductive layer 22 and corresponds to an outer surface of the insulating layer 21. The material of the 25' edge layer 21 may be selected from plastics having better flexibility, such as selected from the group consisting of poly-amine, polytetraethylene, polythiol, "acrylic acid", and polycarbon.
Ο 酸西曰、聚乙稀對苯二酸醋、聚酿亞胺_聚乙稀_對笨二甲醋丑 聚物中之一種或幾種。 、 _導電層22材質可為銅箔、銀箔、金箔或其他常見金屬 4導電層22直接熱成型於絕緣層21之與第二表面川 相對之表面，用於後續製作導電線路。導電層22未與絕緣 層21接觸之表面為第一表面。 覆銅基材20不限於上述結構，如其可包括兩導電層， 即覆銅基材20為雙φ覆銅基材，或覆銅基材2()還可包括 設於絕緣層21與導電層22之間之㈣層，該黏膠層用於 將導電層22黏附於絕緣層21。當覆銅基材2〇為雙面覆銅 基材時，第一表面221及第二表面211分別對應於各導電 層之外表面。 補強板10及覆銅基材20可分別採用卷輪對卷輪之工 藝傳輸，亦可片狀形式提供。本實施例中，採用傳統之片 式工藝製作電路板，故採用片狀形式提供補強板1〇及覆銅 基材20。 第二步’將覆銅基材20黏附於補強板1〇,並使導電層 22露出。 8 201008431 請一併參閱圖1及圖2,覆銅基材20應以第二表面211 •貼合於黏膠層12表面之方式黏附於補強板1〇。該黏附可採 用本領域常用之壓合技術，如真空壓合、傳壓或滾壓方式。 本實施例中，為提高生產效率，將兩覆銅基材2〇分別壓合 至兩黏膠層12，使該兩覆鋼基材2〇分別貼合於黏膠層 之相對兩表面。 ^曰 第二步，於導電層22形成導電線路3〇。 ❹咬導電線路30可經壓膜、曝光、顯影、蝕刻等工藝形成。 喷一併參閱圖2至圖3’首先，鋪設乾膜4〇於覆銅基材2〇 之第一表面221。乾膜40可為正光阻，亦可為負光阻。本 實施例中，僅以負光阻為例，說明其後之曝光、顯影等工 序。由於覆銅基材20壓合有補強板1〇，其厚度增加，且黏 膠層12與覆銅基材2G之間存有黏合力，由此，覆銅基材 20之第二表面211將完全貼合於黏膠層12之表面，而不發 生彎曲或皺折，從而使得鋪設於第一表面221之乾膜各 ❹處厚度一致。其次，請參閲圖4，藉由光罩41對乾膜仞 進仃曝光。該光罩41具有開口 411，開口 411對應於設計 之導電線路圖案。曝光時，與開口 411對應之乾獏4〇受到 光線照射，發生聚合反應，而沒有受到光線照射之乾膜仂 則不發生反應。再次，以顯影液喷琳乾膜4〇。顯影液通常 採，，液，如濃度為2%〜5%之碳酸鈉溶液、氫氧化鈉溶液 或氫氧化鉀溶液。發生了聚合反應之乾膜於顯影液中具有 低溶解度，不被顯影液溶解；而未發生聚合反應之乾膜4〇 則於顯影液中具有高溶解度，可被顯影液溶解。故，經顯 9 201008431 影工序後’請一併參閱圖4及圖5 ’乾膜41於與開口 411 .對應區域之乾膜不被溶解，其餘部分之乾膜都被溶解，從 而暴露出部分導電層22a。再次’以銅I虫刻液或雷射麵刻導 電層22。該姓刻液可為酸性氣化銅溶液。例如，該酸性氯 化銅〉谷液包括亂化銅、鹽酸及過氧化乳。當然，亦可採用 其他任何適用之銅餘刻液進行餘刻。經餘刻後，未被光阻 保護之部分導電層22a將被銅蝕刻液或雷射蝕刻去除，而 ❹被光阻保護之導電層22b則不被蝕刻，請一併參閱圖4及 圖6，由此形成與開口 411圖案一致之導電線路4〇。最後， 請一併參閱圖5至圖7,將殘留於導電層22b表面之光阻除 去’即可得到形成有導電線路40之電路基板1〇〇。 第四步’分離電路基板100與補強板1〇。 請參閱圖8，由於本實施例採用之補強板1〇具有低黏 I1 生故，可採用人工剝離之方式將補強板1〇與電路基板 相分離。當採用卷輪對卷輪之工藝時，需使連接有電路基 ❹板之滾輪帶動電路基板朝遠離補強板之方向運動。 當然’於分離電路基板100與補強板10之前，還可對 電路基板100進行其他製作，如鑛金。 綜上所述，本發明確已符合發明專利之要件，遂依法 提出專利申請。惟，以上所述者僅為本發明之較佳實施方 式，自不能以此限製本案之申請專利範圍。舉凡熟悉本案 技藝之人士援依本發明之精神所作之等效修飾或變化，皆 應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 201008431 圖1係以本技術方案實施例提供之柔性電路板之製作 方法製作單面柔性電路板所採用之補強板及覆銅基材之結 構示意圖。 ' 圖2係以本技術方案實施例提供之柔性電路板之製作 方法製作單面柔性電路板時將補強板壓合至覆銅基材之示 意圖。 圖3係以本技術方案實施例提供之柔性電路板之製作 方法製作單面柔性電路板時於覆銅基材表面壓合乾膜之示 ®意圖。 圖4係以本技術方案實施例提供之柔性電路板之製作 方法製作單面柔性電路板時曝光之示意圖。 圖5係以本技術方案實施例提供之柔性電路板之製作 方法製作單面柔性電路板顯影後之示意圖。 圖6係以本技術方案實施例提供之柔性電路板之製作 方法製作單面柔性電路板時蝕刻導電層之示意圖。 Q 圖7係本技術方案實施例提供之柔性電路板之製作方 法製作單面柔性電路板於導電層形成導電線路之示意圖。 圖8係以本技術方案實施例提供之柔性電路板之製作 方法製作單面柔性電路板時將電路板與補強板分離之示意 圖。 【主要元件符號說明】 補強板 10 覆銅基材 20 11 201008431 基材層 黏膠層 絕緣層 導電層 第一表面 第二表面 導電線路 乾膜 ®光罩 開口 電路基板 π 12 21 22 、 22a 、 22b 221 211 30 40 41 411 100 ❹ 12One or more of bismuth citrate, polyethylene terephthalate, styrene _polyethylene _ benzophenone oligopolymer. The conductive layer 22 may be made of copper foil, silver foil, gold foil or other common metal. The conductive layer 22 is directly thermoformed on the surface of the insulating layer 21 opposite to the second surface for subsequent fabrication of the conductive trace. The surface of the conductive layer 22 that is not in contact with the insulating layer 21 is the first surface. The copper-clad substrate 20 is not limited to the above structure, and may include two conductive layers, that is, the copper-clad substrate 20 is a double φ copper-clad substrate, or the copper-clad substrate 2 may further include an insulating layer 21 and a conductive layer. The (four) layer between 22, the adhesive layer is used to adhere the conductive layer 22 to the insulating layer 21. When the copper-clad substrate 2 is a double-sided copper-clad substrate, the first surface 221 and the second surface 211 correspond to the outer surfaces of the respective conductive layers, respectively. The reinforcing plate 10 and the copper-clad substrate 20 can be transported by a reel-to-reel process, respectively, or in a sheet form. In the present embodiment, the circuit board is fabricated by a conventional chip process, so that the reinforcing plate 1 and the copper-clad substrate 20 are provided in a sheet form. In the second step, the copper clad base material 20 is adhered to the reinforcing plate 1 and the conductive layer 22 is exposed. 8 201008431 Please refer to FIG. 1 and FIG. 2 together, the copper-clad substrate 20 should be adhered to the reinforcing plate 1 以 in such a manner that the second surface 211 is attached to the surface of the adhesive layer 12. The adhesion can be carried out using compression techniques commonly used in the art, such as vacuum compression, pressure transfer or rolling. In this embodiment, in order to improve the production efficiency, the two copper-clad substrates 2 are respectively pressed to the two adhesive layers 12, and the two coated steel substrates 2 are respectively adhered to the opposite surfaces of the adhesive layer. ^曰 In the second step, a conductive line 3 is formed on the conductive layer 22. The bite conductive line 30 can be formed by a process such as lamination, exposure, development, etching, or the like. Referring to Figures 2 to 3' together, first, a dry film 4 is laid on the first surface 221 of the copper-clad substrate 2A. The dry film 40 can be a positive photoresist or a negative photoresist. In the present embodiment, the negative exposure is taken as an example to describe the subsequent exposure, development, and the like. Since the copper-clad substrate 20 is press-fitted with the reinforcing plate 1〇, the thickness thereof is increased, and the adhesive force exists between the adhesive layer 12 and the copper-clad substrate 2G, whereby the second surface 211 of the copper-clad substrate 20 will It completely conforms to the surface of the adhesive layer 12 without bending or wrinkling, so that the thickness of the dry film laid on the first surface 221 is uniform. Next, referring to Fig. 4, the dry film is exposed by the mask 41. The reticle 41 has an opening 411 corresponding to the designed conductive line pattern. At the time of exposure, the cognac 4 corresponding to the opening 411 is irradiated with light to cause a polymerization reaction, and the dry film which is not irradiated with the light does not react. Again, the film was sprayed with a developer solution 4 〇. The developer is usually taken, such as a sodium carbonate solution, a sodium hydroxide solution or a potassium hydroxide solution having a concentration of 2% to 5%. The dry film in which the polymerization reaction has occurred has low solubility in the developing solution and is not dissolved by the developing solution; and the dry film which does not undergo polymerization reaction has high solubility in the developing solution and can be dissolved by the developing solution. Therefore, after the 9 201008431 shadow process, please refer to Figure 4 and Figure 5 'The dry film 41 is in contact with the opening 411. The dry film in the corresponding area is not dissolved, and the remaining part of the dry film is dissolved, thereby exposing the part. Conductive layer 22a. The conductive layer 22 is again engraved with a copper I insect engraving or a laser surface. The surname can be an acidified copper solution. For example, the acidic copper chloride > gluten solution includes chaotic copper, hydrochloric acid, and oxidized milk. Of course, any other suitable copper residual solution can be used for the remainder. After the etch, the portion of the conductive layer 22a that is not protected by the photoresist will be removed by the copper etching solution or laser etching, and the conductive layer 22b whose photoresist is protected by the photoresist is not etched. Please refer to FIG. 4 and FIG. 6 together. Thereby, a conductive line 4A conforming to the pattern of the opening 411 is formed. Finally, referring to Fig. 5 to Fig. 7, the photoresist remaining on the surface of the conductive layer 22b is removed to obtain the circuit substrate 1 on which the conductive line 40 is formed. The fourth step 'separates the circuit substrate 100 from the reinforcing plate 1'. Referring to FIG. 8, since the reinforcing plate 1〇 used in the embodiment has a low-viscosity I1, the reinforcing plate 1〇 can be separated from the circuit substrate by manual peeling. When the reel-to-reel process is adopted, the roller to which the circuit base plate is connected is driven to move the circuit substrate away from the reinforcing plate. Of course, before the circuit board 100 and the reinforcing plate 10 are separated, other fabrications such as gold deposits may be performed on the circuit substrate 100. In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the present invention are intended to be included within the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing the structure of a reinforcing plate and a copper-clad substrate used for fabricating a single-sided flexible circuit board by the method for fabricating a flexible circuit board provided by the embodiment of the present technical solution. 2 is a schematic view of a method of fabricating a flexible circuit board provided by an embodiment of the present technical solution to press a reinforcing plate to a copper-clad substrate when manufacturing a single-sided flexible circuit board. FIG. 3 is a schematic view showing the pressing of a dry film on a surface of a copper-clad substrate when a single-sided flexible circuit board is produced by the method for fabricating a flexible circuit board provided by the embodiment of the present technical solution. FIG. 4 is a schematic diagram of exposure when a single-sided flexible circuit board is fabricated by the method for fabricating a flexible circuit board provided by the embodiment of the present technical solution. FIG. 5 is a schematic diagram showing the development of a single-sided flexible circuit board after the method for fabricating the flexible circuit board provided by the embodiment of the present technical solution. 6 is a schematic diagram of etching a conductive layer when a single-sided flexible circuit board is fabricated by the method for fabricating a flexible circuit board provided by the embodiment of the present technical solution. Q is a schematic diagram of a method for fabricating a flexible circuit board provided by an embodiment of the present technical solution to form a conductive circuit on a conductive layer. FIG. 8 is a schematic diagram of separating a circuit board from a reinforcing board when manufacturing a single-sided flexible circuit board by using the flexible circuit board provided by the embodiment of the present technical solution. [Main component symbol description] Reinforcement plate 10 Copper-clad substrate 20 11 201008431 Substrate layer Adhesive layer Insulation layer Conductive layer First surface Second surface Conductive line Dry film® Shutter open circuit substrate π 12 21 22 , 22a , 22b 221 211 30 40 41 411 100 ❹ 12