200908848 九、發明說明： 【發明所屬之技術領域】 本發明涉及印刷電路板領域，尤其涉及一種多層電路 板製作方法及用於製作多層電路板之内層基板。 【先前技術】 多層印刷電路板係由多於兩層之導電線路與絕緣材料 交替黏結於一起且層間導電線路按設計要求進行互連之印 刷電路板。多層印刷電路板因具有裝配密度高等優點而得 到了廣泛應用，參見文獻Takahashi，A 〇〇ki，Ν· Μ細，A Akahoshi, H. Mukoh, A. Wajima, M. Res. Lab., High density multUayer printed circuit board for HITAC M-880 ^ IEEE Trans. 〇n Components, Packaging, and Manufacturing Technology’ 1992，15(4): 418 425。多層印刷電路板有剛 ^柔性:剛柔結合等多種類型。多層柔性電路板由於體 、小、重里輕’可自由彎曲或折疊等特點近來發展迅速。 目前，多層柔性電路板之製作一般採用傳統多層印刷 I:::製作工藝。首先，製作内層基板，於内層基板上 :作出相應導電線路及導孔；其次，製作其他層基板，於 二他層基板上製作出相應導電線路及導孔；再次，將各層 2加熱:加愿予以黏合並鑛通孔完成各層導電線路； I k而形成多層柔性電路板。該傳統 :電路板之方法，常一片片分開來進行製造二柔 勞動強度大、生產效率低。 費力 200908848 (二柔二'，連續式卷輪對卷輪 對卷輪之製作方、接^日趨成熟。該連續式卷輪 以、拿μ Γ 大柔性電路板之製作效率，苴 j連動场作方切覆銅㈣±製料 /、 =作出柔性電路板。惟，該連續式卷輪對：::作 :广：適用於單層柔性電路板之製作，當製作多層羊： =:由於多層覆銅基材結構導致整個多層柔性電 多層柔性電路板之柔性很大程度降低以 性電路板。 不適用於連續製作多層柔 【發明内容】 有鏗於此，提供—種多層電路板製作方法及用 夕2路板之内層基板，以便連續式進行多層柔性電路板 之裝作’從而提尚多層柔性電路板之製作效率實屬必要。 以下將以實施例說明-種多層電路板製作方法及用於 製作多層電路板之内層基板。 、 該多層電路板之製作方法，其包括以下步驟：提供内 層基板並於該内層基板上製作複數折㈣，該魏折叠部 沿該内層基板長度方向將該内層基板分隔成複數線路ς單 凡，每個折疊部之厚度小於内層基板除折疊部外其他部分 之厚度；於該複數線路板單元中進行電路板製作，製作過 程中使該内層基板於複數折疊部彎折或伸展，從而使複數 200908848 線路板單元依次堆疊 =用=作多層電路板之内層基板，其包括複數折疊BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of printed circuit boards, and more particularly to a method of fabricating a multilayer circuit board and an inner substrate for fabricating a multilayer circuit board. [Prior Art] A multilayer printed circuit board is a printed circuit board in which more than two layers of conductive lines and insulating materials are alternately bonded together and the interlayer conductive lines are interconnected as designed. Multilayer printed circuit boards have been widely used due to their high assembly density, see the literature Takahashi, A 〇〇ki, Ν· Μ, A Akahoshi, H. Mukoh, A. Wajima, M. Res. Lab., High density multUayer printed circuit board for HITAC M-880 ^ IEEE Trans. 〇n Components, Packaging, and Manufacturing Technology' 1992, 15(4): 418 425. Multilayer printed circuit boards are available in a variety of types: rigid: rigid and flexible. Multilayer flexible circuit boards have recently developed rapidly due to their small size, small weight, and light weight. At present, the fabrication of multilayer flexible circuit boards generally uses traditional multi-layer printing I::: fabrication process. First, the inner substrate is fabricated on the inner substrate: corresponding conductive lines and via holes are formed; secondly, other layer substrates are fabricated, and corresponding conductive lines and via holes are formed on the second substrate; again, the layers 2 are heated: Adhesive and merged through holes are used to complete the conductive lines of each layer; I k to form a multilayer flexible circuit board. This tradition: the method of the circuit board, which is often separated by a piece of film to make the second soft labor intensity and low production efficiency. Fei Li 200908848 (two soft two ', the continuous reel to the reel to the reel of the production side, the connection is becoming more and more mature. The continuous reel to take the μ Γ large flexible circuit board production efficiency, 苴j linkage field Square cut copper (4) ± material / / = made of flexible circuit board. However, the continuous reel pair::: made: wide: suitable for the production of single-layer flexible circuit board, when making multi-layer sheep: =: due to multiple layers The copper-clad substrate structure results in the flexibility of the entire multilayer flexible electrical multilayer flexible circuit board to greatly reduce the flexible circuit board. It is not suitable for continuous fabrication of multiple layers of softness. [Invention] In view of this, a multilayer circuit board manufacturing method is provided. It is necessary to use the inner substrate of the 2-way board to continuously perform the mounting of the multilayer flexible circuit board. Therefore, it is necessary to improve the fabrication efficiency of the multilayer flexible circuit board. The following will explain the fabrication method of the multilayer circuit board and the use thereof. An inner layer substrate for manufacturing a multilayer circuit board. The method for fabricating the multilayer circuit board includes the steps of: providing an inner layer substrate and forming a plurality of folds (4) on the inner layer substrate, the Wei folded portion along the inner layer The length of the substrate is divided into a plurality of lines, and the thickness of each folded portion is smaller than the thickness of the inner layer substrate except for the folded portion; the circuit board is fabricated in the plurality of circuit board units, and the manufacturing process is performed. The inner substrate is bent or stretched at the plurality of folded portions, so that the plurality of 200,908,848 circuit board units are sequentially stacked = the inner substrate of the multilayer circuit board is used, which includes the plurality of folded
°丨3亥複數折疊部沿_ & ® I 4c i ώ： I μ内層基板長度方向將該内層基板分 :晶1 板單元，每個折疊部之厚度小於内層基板除 卜其他部分之厚度’該内層基板用於製作多層電路 =時於複數折疊部彎折或伸展，從而使複數線路板單元依 二人堆疊或展開。 與先前技術相比，該多層電路板之製作方法，於内層 基板製作複數折疊部，從而沿該内層基板長度方向將内層 基板分隔成複數連續排狀線路板單元，由於折4部之厚 度^於二層基板除折疊部外其他部分之厚度，柔性增加而 更谷易彎折，故該内層基板可於複數折疊部彎折或伸展， 從而使内層基板之複數線路板單元於電路板製作過程中得 以通過堆豐或展開之方式連續製作複數多層柔性電路板， 即省多層柔性電路板製作之時間及人力，提高多層柔性電 路板之生產效率。 【實施方式】 下面結合附圖及實施例對本技術方案提供之多層電路 板製作方法及用於製作多層電路板之内層基板作進一步說 明。 請參閱圖1’其為本技術方案實施例提供之第一種用於 製作多層電路板之内層基板10。 該内層基板10可為雙面線路板亦可為單面線路板。本 8 200908848 實施例中，該内層基板10為用雙面柔性覆銅基材製作之雙 面線路基板，即該内層基板10包括設置於其相對兩表面: 導電線路13。 該内層基板10具有複數折疊部20,該複數折疊部2〇 沿該内層基板10長度方向間隔設置，每相鄰兩折疊部 之間為一線路板單元Π。故’複數折疊部20將内^基板 1〇分隔成沿該内層基板10長度方向排列之複數線ςς 元11。 每個折疊部20之厚度小於内層基板1〇上除折疊部 之外其他部位之厚度，由於内層基板1〇於複數折疊部如 ，厚度較小’故折疊部20之柔性較内層基板1〇上除折疊 j 20之外其他部位之柔性相對較強，從而内層基板1〇很 容易，外力作用下沿複數折疊部20 |生彎折。本實施例 中’每個折疊部2G包括沿直線排列之複數第-通孔21與 沿直線排列之複數第二通孔22。該複數第—通&21之中二 連j 211與該複數第二通孔22之中心連線平行。該複 、、第通孔21之中心連線211與該複數第二通孔μ之中 ^ =線212之間之距離根據所製作之多層電路板之總厚度 二一十通吊°亥複數第一通孔21之中心連線211與該複數 第二通孔22之中心連線212之間之距離等於或大於壓合於 邮兩们線路板單元U同側表面之兩個線路基板之厚度與 内層基板10之厚度之和。根據所壓合線路基板之不同厚 、、内曰基板10上每個折疊部20之複數第一通孔21之中 連線211與5亥複數第二通孔22之中心連線212之間之距 200908848 離可相同或不相同。由於内層基板1〇於複數第—通孔2i 與複數第二通孔22處厚度減少為零，故複數第—通孔21 與複數第二通孔22處之柔性較内層基板1〇上除折疊部2〇 之外其他部位之柔性相對較強，因此内層基板1()报容易於 外力作用下沿複數第一通孔21之中心連線211與複數第二 通孔22之中心連線212發生彎折。 此外，複數折疊部20還可設計為其他結構，使得每個 折疊部20之厚度小於内層基板1Q之厚度即可^請參閱圖 2其為本技術方案實施例提供之第二種用於製作多層電路 ^之内層基板30。其與内層基板1〇之區別在於，每個折疊 # 35包括一凹槽，該凹槽設置於内層基板之一表面， 該凹槽之延伸方向與内層基板1()之長度方向垂直，該凹槽 於内層基板10長度方向之寬度可根據所製作之多層 路板=總厚度來設計，通常等於或大於壓合於相鄰兩個線 路板單元11同側表面之兩個線路基板之厚度與内層基板 之厚度之和。當然，每個折疊部35亦可包括分別位於内層 基板10相對兩表面呈相對設置之兩個凹槽。 ,巧參閱圖3,其為本技術方案實施例提供之第三種用於 衣作夕。層電路板之内層基板4〇，内層基板與内層基板 10之區別在於，每個折疊部45包括兩個平行排列之凹槽 451該兩個凹槽451之延伸方向與内層基板之長度方向垂 直，且該兩個凹槽451中心線之間之距離可根據所製作之 多層電路板之總厚度來設計，通常等於或大於壓合於相鄰 兩個線路板單元u同側表面之兩個線路基板之厚度與内層 10 200908848 基板ίο之厚度之和。 本技術方案實施例提供之多層電路板之製作方法 採用内層基板10製作而成，具體包括以下步驟。 、 第一步，提供内層基才反10，於t亥内層基板ι〇上擎 數折豐部20 ’該複數折疊部2G沿該内層基板 將該内層線路板K)分隔成複數線路板單幻 “向 加之厚度小於内層基板10除折疊部2〇外其他部分之^ 衫施射，該㈣基板1()為雙㈣路基板，故該又内 :請採用柔性單面或雙面覆銅基材，將整張覆銅基材 …枓按實際製程需要進行分條，形成帶狀覆銅基材。該帶 狀覆銅基材可卷設於卷輪上用以連續式製作㈣基板⑺。 该内層基板1〇包括設置於其相對兩表面之導電線路m 導電線路13可採用曝錢影_或㈣動丨等方法製作了 該複數折疊部20可於内層基板1〇製作導電線路^之 前製作形成’亦可Μ層基板1G製作導電線路η之後製 作形成。該複數折疊部2G可通過沖孔、機械鑽孔、雷射二 孔或化學兹刻等方法形成。 第一步，於該線路板單元u上進行電路板製作，製作 過程中使該内層基板10於複數折疊部2〇處彎折或伸展， 從而使複數線路板單元u依次堆疊或展開。 該電路板製作包括壓合線路基板、導孔製作、表層導 電線路製作、保護膜壓合及檢測成型等電路板製程中採用 之製作步驟。本實施例中，以壓合線路基板為例進行說 明，根據電路板製作設計要求，可僅於内層絲1〇之每個 11 200908848 線路板單元11之一表面壓合線路基板，亦可於内層基板10 之每個線路板單元11之相對兩表面分別壓合線路基板。本 實施例中，内層基板10之每個線路板單元11之相對兩表 • 面分別壓合了線路基板。所壓合之線路基板包括絕緣層與 — 導電層。線路基板之絕緣層直接與線路板單元11之導電線 路13表面接觸，並壓合於線路板單元11相對兩表面。當 然，每個線路板單元11所壓合之線路基板之厚度與層數可 相同亦可不相同。壓合了線路基板之内層基板10於複數折 疊部20彎折，使壓合了線路基板之複數線路板單元11依 次堆疊起來。即，後一壓合了線路基板之線路板單元11通 過内層基板10於相應折疊部20彎折而疊放於前一壓合了 線路基板之線路板單元11，從而使複數壓合了線路基板之 線路板單元11依次堆疊起來。 下面進一步說明具體之壓合堆疊過程，壓合時，如圖4 所示，内層基板10可由卷輪15卷出，第一折疊部201與 第二折疊部202沿内層基板10長度方向將内層基板10分 隔成第一線路板單元111、第二線路板單元112及第三線路 板單元113。第一線路板單元111之相對兩表面分別壓合了 第一線路基板301與第二線路基板401 ;第二線路板單元 112之相對兩表面分別壓合了第三線路基板302與第四線路 基板402;第三線路板單元113之相對兩表面分別壓合了第 五線路基板303與第六線路基板403。第一線路基板301、 第二線路基板401、第三線路基板302、第四線路基板402、 第五線路基板303與第六線路基板403之厚度可相同亦可 12 200908848 不' 相同。 〜堆疊時’如圖5所示，由於該第—折疊部2〇1之複數 弟-通孔則之中心連線與該複數第二通孔則 =… =等於内層基板1〇之厚度、璧合於第-線： 板早兀ill之第-線路基板301之厚度以及墨合於第 路板早兀112之第三線路基板3〇2之厚度之和即數 =通孔則之中心連線與該複數第二通孔衝之中心 連線之間之距離等於壓合於相鄰兩個線路板翠元Η同 面之兩個線路基板之厚度與㈣基板lG之厚 二 基板10可於第一折疊部201 f折 又 内層 ,110结1丨川丄4折，攸而使壓合於第二線路 板早兀112之弟二線路基板3〇2與 m之第一線路基板3G1貼合。 、線路板早兀 同樣地’由於該第二折疊部搬之複數第—通孔2〇2ι =中心連線與該複數第二通孔助之中心連線 等於内層基板Η)之厚度、壓合於第二線路板單^ 112之巨= 四線路基板402之厚度與壓合於第三線路板單元U 六線路基板彻之厚度之和，即該複數第-通孔2G21之中 j線與該複數第二通孔助之中心連線之間之距離等於 塵5於相鄰兩個線路板單元11同側表面之兩個線路基板之 厚度與内層基板1G之厚度之和。㈣基板1G於^t 部202 f折，從而使壓合於第三線路板單元⑴之第六ς 路基板403與壓合於第-綠4 _ 、’、 4_人。“… 早 之第四線路基板 ' ° ，3亥第二線路板單元112就疊放於第二線路 板單元m，該第三線路板單元113就疊放於第二線路板單 13 200908848 元112，以此類推，從而使得複數線路板單元11連續依次 堆叠起來。 因為線路板單元11於壓合線路基板時使用了黏膠劑黏 合，當複數線路板單元11堆疊起來時，可能會出現溢膠現 象，由於溢出黏膠劑之黏合作用，可能使得堆疊起來之複 數線路板單元11不易展開。優選地，複數線路板單元11 堆疊時，可於相互貼合之線路基板之間設置隔離膜。例如， 可於壓合於第一線路板單元111之第一線路基板301與壓 合於第二線路板單元112之第三線路基板302之間，以及 壓合於第二線路板單元112之第四線路基板402與壓合於 第三線路板單元113之第六線路基板403之間放置隔離 膜，例如卡西紙。 當然，當内層基板10於第一折疊部201與第二折疊部 202處伸展時，該第三線路板單元113可相應從第二線路板 單元112展開，第二線路板單元112亦可相應從第一線路 板單元111展開，以此類推，從而使得複數線路板單元11 連續依次展開，以便於進行相應之電路板之製作過程。 例如，壓合了線路基板之複數線路板單元11還需要經 過後續之烘烤、導孔製作、表層導電線路製作、保護膜壓 合及檢測成型等步驟才能完成多層柔性電路板之製作。於 這些後續製作過程中，如圖6所示，該壓合了線路基板之 複數線路板單元Π均可按照前述方式進行堆疊或展開，展 開之線路板單元11可進行相應之製作步驟，完成相應製作 步驟之線路板單元11又可依次堆疊起來，從而連續地進行 14 200908848 Ιί二柔性電路板之製作。例如’壓合了線路基板之複 早70 11可堆疊起來進行烘烤；可展開進行導孔製 表層‘電線路製作及保護膜壓合等。 、’】也於电路板之導孔製作及表層導電線路製作之 L鑛過私中’為了便於進行整體電鍵，優選地，如圖7所 不’可於相鄰兩個線路板單元11之間貼合至少一導電膠帶 =用於連接相鄰之導電線路13，以確保電錄銅時相鄰之 、、·板早几11之導電線路13之間電氣導通。該 =可採用熱溶法或超聲波溶接法貼合於導電線路13，料 呆¥電勝帶50於電鑛等後續步驟令之穩定性。 本發料已符合發日料敎要件，遂依法 2射請。惟，以上所述者僅為本發明之較佳實施方 "，不能以此限制本案之申請專利範圍。舉凡孰朵本案 人士援依本發明之精神所作之等效修•或變：，皆 U函盍於以下申請專利範圍内。 【圖式簡單說明】 f 1係本技術方案實施難供U内層基板之結 構不意圖。 =2係本技術方案實施例提供之第二種㈣基板 構不意圖。 ^係本技術方讀施例提供之第三種㈣基板之結 稱不意圖。 圖4係本技術方案實施例提供之内層基板愿 板之示意圖。 15 200908848 圖5本技術方案實施例提供之壓合了線路基板之内層 基板之堆疊示意圖。 圖6本技術方案實施例提供之多層電路板製作過程中 複數線路板單元之堆疊展開示意圖。 圖7本技術方案實施例提供之多層電路板製作過程中 貼合導電膠帶之示意圖。 【主要元件符號說明】 内層基板 10， 30，40 線路板單元 11 導電線路 13 卷輪 15 折疊部 20 v 35，45 第一通孔 21， 2011 ， 2021 第二通孔 22， 2012 ， 2022 第一通孔之中心連線 211 第二通孔之中心連線 212 凹槽 451 第一線路板單元 111 第二線路板單元 112 第三線路板單元 113 第一折疊部 201 第二折疊部 202 第一線路基板 301 16 200908848 第二線路基板 401 第三線路基板 302 第四線路基板 402 . 第五線路基板 303 , 第六線路基板 403 導電膠帶 50 17丨 丨 亥 亥 亥 折叠 _ _ _ _ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 内 内 内 内 内 内 内 内 内 内 内The inner substrate is used to make a multilayer circuit = when the plurality of folded portions are bent or stretched, so that the plurality of circuit board units are stacked or unfolded by two people. Compared with the prior art, the multilayer circuit board is manufactured by forming a plurality of folded portions on the inner substrate, thereby dividing the inner substrate into a plurality of continuous row circuit board units along the length of the inner substrate, because the thickness of the four portions is The thickness of the other portion of the second layer substrate except the folded portion is increased in flexibility and is more easily bent. Therefore, the inner substrate can be bent or stretched in the plurality of folded portions, so that the plurality of circuit board units of the inner substrate are in the process of manufacturing the circuit board. It is possible to continuously manufacture a plurality of multi-layer flexible circuit boards by stacking or unfolding, that is, to save time and manpower for manufacturing multilayer flexible circuit boards, and to improve the production efficiency of the multilayer flexible circuit boards. [Embodiment] Hereinafter, a method of fabricating a multilayer circuit board provided by the present technical solution and an inner substrate for manufacturing a multilayer circuit board will be further described with reference to the accompanying drawings and embodiments. Please refer to FIG. 1 ' which is the first inner substrate 10 for fabricating a multilayer circuit board according to an embodiment of the present technical solution. The inner substrate 10 can be a double-sided circuit board or a single-sided circuit board. In the embodiment of the present invention, the inner substrate 10 is a double-sided circuit substrate made of a double-sided flexible copper-clad substrate, that is, the inner substrate 10 is disposed on opposite surfaces thereof: a conductive line 13. The inner substrate 10 has a plurality of folded portions 20 which are spaced apart along the longitudinal direction of the inner substrate 10, and each of the adjacent folded portions is a circuit board unit. Therefore, the plurality of folded portions 20 divide the inner substrate 1 成 into a plurality of line elements 11 arranged along the longitudinal direction of the inner layer substrate 10. The thickness of each of the folded portions 20 is smaller than the thickness of the portion of the inner substrate 1 other than the folded portion. Since the inner substrate 1 is folded over the plurality of folded portions, for example, the thickness is small, so the flexibility of the folded portion 20 is higher than that of the inner substrate 1 The flexibility of the other parts except the folding j 20 is relatively strong, so that the inner substrate 1 〇 is easy, and the external folding is bent along the plurality of folded portions 20 . In the present embodiment, each of the folded portions 2G includes a plurality of first through holes 21 arranged in a straight line and a plurality of second through holes 22 arranged in a straight line. The second connection j 211 of the plurality of first-pass & 21 is parallel to the center line of the plurality of second through holes 22. The distance between the center line 211 of the complex and the first through hole 21 and the ^= line 212 of the plurality of second through holes μ is determined according to the total thickness of the fabricated multilayer circuit board. The distance between the center line 211 of a through hole 21 and the center line 212 of the plurality of second through holes 22 is equal to or greater than the thickness of the two circuit substrates pressed to the same side surface of the board unit U of the mail board. The sum of the thicknesses of the inner substrate 10. Between the different thicknesses of the pressed circuit substrate, between the plurality of first through holes 21 of each of the folded portions 20 of the inner turn substrate 10 and the center line 212 of the second plurality of second through holes 22 Can be the same or different from 200908848. Since the thickness of the inner substrate 1 at the plurality of through holes 2i and the plurality of second through holes 22 is reduced to zero, the flexibility of the plurality of first through holes 21 and the plurality of second through holes 22 is smaller than that of the inner substrate 1 The flexibility of the other portions other than the portion 2 is relatively strong, so that the inner substrate 1 () is reported to be easily applied by the external force along the center line 211 of the plurality of first through holes 21 and the center line 212 of the plurality of second through holes 22 Bend. In addition, the plurality of folds 20 can also be designed as other structures, such that the thickness of each of the folded portions 20 is smaller than the thickness of the inner layer substrate 1Q. Please refer to FIG. 2 for the second embodiment of the present invention. The inner substrate 30 of the circuit ^. The difference from the inner substrate 1 在于 is that each of the folds # 35 includes a groove disposed on a surface of the inner substrate, the groove extending in a direction perpendicular to the length direction of the inner substrate 1 (), the concave The width of the groove in the longitudinal direction of the inner substrate 10 can be designed according to the manufactured multilayer board = total thickness, and is generally equal to or larger than the thickness and inner layer of the two circuit substrates which are pressed on the same side surface of the adjacent two circuit board units 11. The sum of the thicknesses of the substrates. Of course, each of the folded portions 35 may further include two recesses respectively disposed opposite to each other on the inner surface of the inner substrate 10. Referring to FIG. 3, it is a third device provided for the embodiment of the technical solution. The inner substrate 4 of the layer circuit board is different from the inner substrate 10 in that each folded portion 45 includes two parallelly arranged grooves 451 extending in a direction perpendicular to the length direction of the inner substrate. And the distance between the center lines of the two grooves 451 can be designed according to the total thickness of the fabricated multilayer circuit board, and is usually equal to or larger than two circuit substrates pressed on the same side surface of the adjacent two circuit board units u. The thickness is the sum of the thickness of the inner layer 10 200908848 substrate ίο. The method for fabricating the multilayer circuit board provided by the embodiment of the present technical solution is made by using the inner substrate 10, and specifically includes the following steps. In the first step, the inner layer is provided to be reversed, and the inner layer of the inner layer of the substrate is divided into a plurality of circuit boards (the inner layer circuit board K) along the inner substrate. "In the case of a shirt having a thickness smaller than that of the inner substrate 10 except for the folded portion 2, the (4) substrate 1 () is a double (four) substrate, so the inside: please use a flexible single-sided or double-sided copper-clad substrate. The entire copper-clad substrate is stripped according to the actual process, and a strip-shaped copper-clad substrate is formed. The strip-shaped copper-clad substrate can be wound on a reel for continuous fabrication of the (4) substrate (7). The inner substrate 1 〇 includes a conductive line disposed on opposite surfaces of the two. The conductive line 13 can be formed by a method such as exposure or shadowing. The plurality of folded portions 20 can be fabricated before the conductive substrate is fabricated on the inner substrate 1 . The formation of the conductive layer η can also be formed by forming the conductive layer η. The plurality of folded portions 2G can be formed by punching, mechanical drilling, laser two-hole or chemical etching. The first step is on the circuit board. The board is fabricated on the unit u, and the inside is made during the production process. The layer substrate 10 is bent or stretched at the plurality of folded portions 2〇, so that the plurality of circuit board units u are sequentially stacked or unfolded. The circuit board is fabricated including a laminated circuit substrate, a via hole fabrication, a surface conductive circuit fabrication, and a protective film bonding. And the manufacturing steps used in the process of detecting the forming of the circuit board, etc. In this embodiment, the pressing circuit substrate is taken as an example for description, and according to the circuit board design and design requirements, only the inner layer 1 2009 each of the 11 200908848 circuit board units 11 one surface press-bonding circuit substrate, and the circuit substrate may be respectively pressed on opposite surfaces of each of the circuit board units 11 of the inner substrate 10. In this embodiment, the opposite two of each of the circuit board units 11 of the inner substrate 10 The surface of the circuit board is respectively pressed by the surface substrate. The circuit substrate to be laminated includes an insulating layer and a conductive layer. The insulating layer of the circuit substrate directly contacts the surface of the conductive line 13 of the circuit board unit 11 and is pressed against the circuit board unit 11 Corresponding to the two surfaces. Of course, the thickness of the circuit substrate pressed by each circuit board unit 11 may be the same or different from the number of layers. The inner layer of the circuit substrate is pressed together. 10, the plurality of folded portions 20 are bent, and the plurality of circuit board units 11 which are pressed against the circuit substrate are sequentially stacked. That is, the circuit board unit 11 which is pressed against the circuit substrate is bent by the inner substrate 10 at the corresponding folded portion 20. And stacked on the circuit board unit 11 of the previous circuit board, so that the plurality of circuit board units 11 which are pressed together with the circuit board are sequentially stacked. The specific press-stacking process is further explained below, when pressing, as shown in the figure 4, the inner substrate 10 can be unwound by the reel 15, and the first folded portion 201 and the second folded portion 202 divide the inner substrate 10 into the first circuit board unit 111 and the second circuit board unit 112 along the length direction of the inner substrate 10. And the third circuit board unit 113. The opposite surfaces of the first circuit board unit 111 respectively press the first circuit substrate 301 and the second circuit substrate 401; the opposite surfaces of the second circuit board unit 112 are respectively pressed into the third The opposite surfaces of the circuit substrate 302 and the fourth circuit substrate 402 and the third circuit board unit 113 are respectively pressed against the fifth circuit substrate 303 and the sixth circuit substrate 403. The thicknesses of the first circuit substrate 301, the second circuit substrate 401, the third circuit substrate 302, the fourth circuit substrate 402, the fifth circuit substrate 303, and the sixth circuit substrate 403 may be the same or may not be the same. When the stacking is as shown in Fig. 5, since the center line of the plurality of ridges-through holes of the first-folding portion 2〇1 and the second number of the second through holes are =... = equal to the thickness of the inner substrate 1 璧In combination with the first line: the thickness of the first-line substrate 301 of the board and the thickness of the third line substrate 3〇2 of the ink board of the first board 112 is the center line of the through hole The distance between the line connecting the center of the plurality of second through holes is equal to the thickness of the two circuit substrates which are pressed to the same side of the adjacent two circuit boards, and (4) the thickness of the substrate 1G. A folding portion 201 is folded into the inner layer, and the first layer substrate 3G1 of the second circuit board 3〇2 and the second circuit board 3G1 which are pressed against the second circuit board is bonded to the first circuit board 3G1. The circuit board is similarly the same as the thickness of the inner substrate Η2ι = the connection between the center line and the center of the plurality of second through holes is equal to the thickness of the inner substrate 、) The thickness of the second circuit board unit 112=the thickness of the four-circuit substrate 402 and the thickness of the circuit board of the third circuit board unit U6, that is, the sum of the thickness of the plurality of first-via holes 2G21 and the The distance between the center lines of the plurality of second through holes is equal to the sum of the thicknesses of the two circuit substrates of the dust 5 on the same side surface of the adjacent two circuit board units 11 and the thickness of the inner substrate 1G. (4) The substrate 1G is folded at the portion 202, so that the sixth routing substrate 403 which is pressed against the third wiring board unit (1) is pressed against the first-green 4 _ , ', 4_ person. "...the fourth fourth circuit board ' ° , the third circuit board unit 112 is stacked on the second circuit board unit m, and the third circuit board unit 113 is stacked on the second circuit board single 13 200908848 yuan 112 And so on, so that the plurality of circuit board units 11 are successively stacked in order. Since the circuit board unit 11 uses adhesive bonding when pressing the circuit substrate, when the plurality of circuit board units 11 are stacked, overflow may occur. Phenomenon, due to the adhesion of the overflowing adhesive, it is possible to make the stacked plurality of circuit board units 11 difficult to deploy. Preferably, when the plurality of circuit board units 11 are stacked, an isolation film may be disposed between the circuit substrates that are bonded to each other. The first circuit substrate 301 that is press-fitted to the first circuit board unit 111 and the third circuit substrate 302 that is pressed into the second circuit board unit 112, and is pressed into the fourth circuit board unit 112. A separator film, such as a smectic paper, is placed between the circuit substrate 402 and the sixth circuit substrate 403 that is press-fitted to the third circuit board unit 113. Of course, when the inner substrate 10 is folded over the first folded portion 201 and the second When the portion 202 is extended, the third circuit board unit 113 can be unfolded from the second circuit board unit 112, the second circuit board unit 112 can also be unfolded from the first circuit board unit 111, and so on, thereby making the multiple lines The board unit 11 is sequentially unfolded in order to facilitate the process of fabricating the corresponding circuit board. For example, the plurality of circuit board units 11 that are pressed together with the circuit substrate also need to be subjected to subsequent baking, via hole fabrication, surface conductive circuit fabrication, and protective film. The steps of pressing and detecting molding can complete the fabrication of the multilayer flexible circuit board. In these subsequent fabrication processes, as shown in FIG. 6, the plurality of circuit board units 压 which are pressed against the circuit substrate can be stacked or unfolded as described above. The unfolded circuit board unit 11 can perform corresponding manufacturing steps, and the circuit board unit 11 that completes the corresponding manufacturing steps can be sequentially stacked, thereby continuously performing 14 200908848 Ιί two flexible circuit boards. For example, 'pressing the circuit substrate The early 70 11 can be stacked for baking; it can be unfolded for the guide hole surface layer 'electric circuit production and protective film pressure Etc., '] is also in the production of the guide hole of the circuit board and the surface of the conductive line made of L mine in the private 'to facilitate the overall key, preferably, as shown in Figure 7 can be adjacent to the two circuit board unit 11 Between the at least one conductive tape = for connecting the adjacent conductive lines 13 to ensure electrical conduction between the adjacent conductive lines 13 of the adjacent plates when the copper is recorded. The method or the ultrasonic welding method is applied to the conductive line 13, and the stability of the material is in compliance with the subsequent steps of the electric ore, etc. The hair material has been in compliance with the requirements of the date of delivery, and is required to be shot according to law. The above is only the preferred embodiment of the present invention, and the scope of the patent application of the present invention cannot be limited thereto. Equivalent repairs or changes made by the person in charge of the case in accordance with the spirit of the present invention are all within the scope of the following patent application. [Simple description of the diagram] f 1 is a schematic of the technical solution of the U inner substrate. = 2 is the second (four) substrate structure provided by the embodiment of the present technical solution. ^ The structure of the third (four) substrate provided by the technical method is not intended. 4 is a schematic diagram of an inner substrate wishing plate provided by an embodiment of the present technical solution. 15 200908848 FIG. 5 is a schematic view showing the stacking of the inner substrate of the circuit substrate provided by the embodiment of the present technical solution. FIG. 6 is a schematic diagram showing the stacking of a plurality of circuit board units in the manufacturing process of the multi-layer circuit board provided by the embodiment of the present technical solution. Figure 7 is a schematic view showing the lamination of a conductive tape during the fabrication of the multilayer circuit board provided by the embodiment of the present technical solution. [Main component symbol description] Inner substrate 10, 30, 40 Circuit board unit 11 Conductive line 13 Reel 15 Folding portion 20 v 35, 45 First through hole 21, 2011, 2021 Second through hole 22, 2012, 2022 First Center line of the through hole 211 Center line 212 of the second through hole Groove 451 First circuit board unit 111 Second circuit board unit 112 Third circuit board unit 113 First folding portion 201 Second folding portion 202 First line Substrate 301 16 200908848 Second circuit substrate 401 Third circuit substrate 302 Fourth circuit substrate 402. Fifth circuit substrate 303, sixth circuit substrate 403 Conductive tape 50 17