200908025 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種用於高速傳輸數位資料等之平整狀 的高速差動傳輸電纜。 【先前技術】 在欲以高速傳輸數位資料之情形，必須將資料信號從 高位準轉移至低位準（或是從低位準轉移至高位準）爲止 之時間（所謂的遷移時間）縮短。在縮短遷移時間上，縮 小信號振幅即可。但是，一旦縮小信號振幅時，將有外部 雜訊變弱之問題。因此，習知乃使用一對信號線傳輸反相 位之信號，在資料接收側，將傳輸信號之差分作爲資料的 差動傳輸方法。此方法係在傳輸信號之接收側，輸出逆相 位之信號差分。即使縮小傳送側之信號振幅，此差分輸出 在接收側之信號振幅還是成爲2倍。在傳輸路徑中，進入 之雜訊係在一對信號線上呈相同地重疊而相抵消。 上述之信號傳輸係所謂的低電壓差動信號方式 (LVDS ： Low Voltage Differential Signaling)，利用小的 電壓變化差動信號在一對導線傳輸資料信號，能夠實現高 速、低消耗電力與低雜訊。如此之信號傳輸方式係有效使用 於利用一條電纜傳輸影像信號、聲音信號、控制信號之屬整 合介面的 HDMI ( High-Definition Multimedia Interface:高 清晰度多媒體介面）及連接電腦與硬碟之屬介面的串行式 ATA ( Advanced Technology Attachment :進階技術附件） 等。 200908025 依照如上述之用途，針對傳輸高速差動信號’例如’ 使用如知專利文獻1揭示之電纜。此電纜’有例如是將如 第5圖所示之複數條差動電纜排成簾狀的所謂簾狀電纜。 此簾狀電纜9係把將屏蔽如顯示於第5 ( A )圖之一對信號 線而成的差動電纜8，以如第5 ( B )圖所示般地使複數條 平行排成一列而相鄰的差動電纜彼此間予以熱熔融所形 成。 各差動電纜8係利用電介質層2被覆中心導體1’在 其外圍設置皮層3以作成信號線，平行排列此2條信號線 (4 a、4 b )所形成。接著，在平行排列的信號線4 a與4 b 之兩外側，配設有汲線5 a、5 b。然後，一面保持此配置構 造，並一面將由金屬箔膠帶所構成的外部導體6捲繞於其 外圍，再利用套管層7被覆其外側而作成最終構造。 中心導體1係例如使用絞合7條鍍銀之軟銅線而作成 外徑0.609mm(AWG24號）的絞合線。電介質層2係將0.37mm 厚度之多孔質PTFE (四氟化乙烯樹脂）膠帶被覆於中心導 體1之外圍所形成。皮層3係利用厚度〇.〇9mm之PEP (四 氟化乙烯-六氟化丙烯共聚物樹脂）形成，覆蓋電介質層2 之外面。 汲線5 a、5 b之直徑係較中心導體1爲細，使用絞合7 條鍍銀之軟銅線而作成外徑0.306mm ( AWG30號）的絞合 線。外部導體6係以螺旋狀或縱向附加之方式捲繞金屬蒸 鍍膠帶而形成。套管層7係利用厚度0.25mm之非鹵素難燃 性烯烴樹脂予以形成，將長徑側之外徑作成4.3mm，將此 200908025 套管層複數組平行排成一列’並將長徑側之側面彼此間熔 融後予以一體化。 專利文獻1 :日本專利特開2 0 0 2 - 3 0 4 9 2 1號公報 【發明內容】 發明所欲解決之技術問i 隨著電漿顯示器或液晶顯示器朝大型化發展，作爲其 機器內配線材所使用之信號傳輸電纜也將變長。現在，將 已配線有約數十。111長度之電纜’例如’欲配線成2m以上 之長度。此情形下’傳輸損失之問題將發生’以單純加長 現行之電纜即可這樣而言’因應將變得困難。例如，在信 號傳輸電纜被使用於高頻領域之情形，隨著頻率變高，被 覆著信號線之電介質層的介電損失也將變大。尤其，H D ΜI 之使用頻率爲8 2 5 MHz以上，此情形之傳輸損失將成爲不 可忽視之値。 爲了避免信號傳輸電纜之傳輸損失的增加，必須增大 中心導體等之粗度，於第5圖揭示之簾狀電纜中，電纜直 徑將變大。因此，柔軟性降低，操作性變差的同時，配線 間隙之問題也將顯現出來。 本發明係有鑑於上述之實情所完成者，其目的在於提 供一種在不使電纜直徑增加之下，由低損失化之複數個信 號線對所構成之平整狀的高速差動傳輸電纜。 解決問題之.技術丰段 依照本發明所得的高速差動傳輸電纜，其係作成以2 條電導體爲一組而進行差動傳輸之信號線對，將複數個該 200908025 信號線對配列成平整狀，擠出絕緣樹脂而加以被覆的高速 差動傳輸電纜；以既定之間隔將由複數條單心線或絞合線 所構成的電導體平行排成一列，利用由絕緣樹脂所構成的 絕緣體予以一體被覆’再縱向附加金屬箔膠帶以覆蓋該絕 緣體之外圍。另外’也可以作成利用由絕緣樹脂所構成的 外層被覆覆蓋該金屬箔膠帶之外圍。 於該複數組之各信號線對間配設地線，以使信號線對 間之耦合得以減低。另外，使汲線電性接觸該金屬箔膠帶 後而予以配設，容易進行金屬箔膠帶之接地連接。還有， 複數條電導體的間隔係設定成0.5mm以下之狹窄間距，使 得既定之傳輸特性可以得到之方式來進行。另外，絕緣體 與金屬箔膠帶係藉由黏著劑被黏著，利用有條紋的鋼板之 圖案將所需要之黏著劑塗布於絕緣體或金屬箔膠帶上。 另外，該金屬箔膠帶係被捲繞於絕緣體有1.5層以上 而具有難燃性。金屬箔膠帶之外圍被外層被覆所覆蓋之情 形，利用聚胺甲酸酯樹脂與乙烯-醋酸乙烯酯共聚合樹脂之 混合樹脂形成外層被覆而使其具有難燃性。 另外，於絕緣體中添加0.4重量％〜0.6重量％之碳 黑’使利用YAG雷射所進行之金屬箔加工成爲容易。另外， 也可以作成將較該金屬箔膠帶未切斷之最小彎曲半徑爲大 的彎曲半徑之彎曲限制構件裝配在電纜所折彎之位置上的 構造。 〔發明之效果〕 若根據本發明，不用加粗信號線之直徑，即能夠實現 200908025 低損失之高速差動傳輸電纜，即使電子機器間或電子機器 內之配線距離變長之情形下，也能夠抑制損失增加，有效 進行高速下之信號傳輸。 〔發明之實施形態〕 藉由圖示以說明本發明之實施形態。第丨圖係顯示無 外層被覆之電纜剖面，第2圖係顯示具有外層被覆之電纜 剖面。於圖中’ 1 0a與1 〇b係表示高速差動傳輸電纜、i 1 係表示電導體、12係表示絕緣體、13係表示金屬箔膠帶、 1 4係表示汲線、1 5係表示外層被覆' s p與S ϋ係表示信號 線、S係表示信號線對、g係表示接地線。 本發明之高速差動傳輸電纜l〇a係如第丨圖所示，以 既定之間隔將複數條電導體1 1平行排成一列所形成。此等 複數條電導體1 1係被由絕緣樹脂所構成的絕緣體1 2所被 覆，作爲屏蔽導體之金屬箔膠帶1 3將縱向附加於電纜長邊 方向後而捲繞於其外側。另外必要時，使汲線1 4電性接觸 於金屬箔膠帶13之方式來予以配設於與絕緣體〗2之間。 還有’此汲線1 4較佳爲配設於電纜側緣之單側或兩側。 電導體11能夠使用銅或鋁等之電良導體或是在此等 之上實施鍍錫或銀之單心線或絞合線^期望電導體1 1之外 形爲縱與橫幾乎相等之圓形線狀物。於平整電纜中，雖然 也有使用平形導體物’藉由使用圓形線狀之導體，能夠加 強予以差動傳輸之信號間的耦合。另外，藉由加強信號間 的稱合’能夠縮小屏蔽導體（金屬箱膠帶1 3 )所誘導之渦 電流及因此渦電流所造成之焦耳損失，將之視爲低減衰。 200908025 另外，基於可撓性之觀點，電導體U係絞合線較單心 線爲佳。例如，能夠使用絞合7條外徑0.06mm之導線（相 當於AWG34號、外徑〇.l8mm)的絞合線。此電導體係以 既定之間距P而在同一平面上，平行排成一列，利用因絕 緣樹脂之擠壓成形所得的絕緣體1 2予以一體被覆後而作 成平整狀之多心絕緣電纜形狀。 絕緣體1 2係使電導體1 1間予以電性絕緣，相對於高 頻區域上之使用，介於電導體1 1間與金屬箔膠帶之間，發 揮作爲形成靜電結合之電容的功能。因此，絕緣體1 2也稱 爲電介質，其電介質正切（tan5)及電容率（ε)也成爲左 右傳輸電纜特性之參數。基於減少電介質損失之觀點，期 望絕緣體12之電介質正切越小越好，另外，爲了使電纜直 徑變細，期望電容率越小越好。 因而’無論絕緣體12之電介質正切及電容率中任一 種’皆可謂較低者之傳輸損失也較小，能夠有效傳輸高頻 信號。但是’與機器之連接且確保既定之特性阻抗，也必 須考量電介質材料與形狀之組合。 於本發明中，例如，將聚烯烴系樹脂使用於形成此絕 緣體1 2之絕緣樹脂中，例如，能夠使用聚乙稀樹脂等。聚 乙烯樹脂之電介質正切約爲4xl〇-4，電容率爲2.3〜24, 較聚乙烯樹脂爲小（例如，PET之電介質正切約爲2χ1〇-3, 電容率約爲2 · 9〜3.0 )，可謂較佳之材料。還有，相對於 以既定之間隔所配列之複數條電導體1 1，此絕緣體1 2期 望使用擠壓機予以擠壓成形。 -10- 200908025 擠壓成形絕緣體12之情形’絕緣體12之上下平面期 望於電導體1 1間不生成如凹陷之平坦面而予以形成。藉 此，能夠使各電導體1 1與絕緣體12之外圍所捲繞之金屬 箔膠帶1 3的間隔得以一定，作成均勻特性之阻抗。 金屬箔膠帶13係與於如上所述之電導體11中之信號 線間，形成既定之靜電容量分布’使既定之特性阻抗可以 得到之方式來進行。另外’金屬箱膠帶1 3係覆蓋絕緣體 12之外圍，具備發揮防止來自外部之雜音信號（雜訊）侵 入或向外部之信號漏出之功能。 此金屬箔膠帶13係使鋁或銅等之金屬箔〗3a貼合於聚 對苯二甲酸乙二酯（PET)等之塑膠基材13b或蒸鍍予以形 成。金屬箔13a與塑膠基材13b可以使用厚度爲數μηι〜數十 μηα者。金屬箔膠帶13的整體厚度可使用0.01mm〜0_05mm 者。例如，能夠將厚度9μιη之銅箔作爲金屬箔13a使用， 將厚度6μιη之PET作爲塑膠基材13b使用，使用整個厚度 作成1 5μηι之CuPET膠帶。 此金屬箔膠帶1 3係將其金屬箔面作爲內側，於絕緣體 1 2予以縱向附加、以絕緣體1 2之寬度予以折彎，至少其 重疊部分係藉由黏著劑1 3 c予以黏著固定。藉由使金屬箔 膠帶13之金屬箔面作爲內側，由於金屬箔不露出電纜外 面，即使無外層被覆，也能夠具有作爲電纜之一定範圍的 耐久性。另外，由於金屬箔膠帶1 3在與電導體1 1之間必 須採取阻抗整合，與電導體1 1之隔離距離必須固定。爲 此，不利用外層被覆1 5覆蓋金屬箔膠帶1 3的外圍之情形， 金屬箔膠帶1 3較佳爲牢固貼附於絕緣體1 2。但是，並無 200908025 整面無間隙地塗布黏著劑之必要，如後所述，若使金屬箔 膠帶1 3不浮現之方式來加以貼附的話，黏著劑也可以條紋 狀等予以部分塗布。 金屬箔膠帶1 3本身爲容易接地連接之情形，汲線j 4 則不一定必要。但是，藉由使用汲線1 4，能夠使金屬箔膠 帶1 3之接地連接成爲容易，必要時予以設置。此汲線i 4 係與上述之電導體1 1予以分開設置，於電纜之側緣單側或 兩側’利用絕緣體1 2與金屬箔膠帶1 3夾持之方式來予以 配設。還有，可以將相同於電導體1 1之物使用於汲線1 4， 也可以爲較電導體1 1爲細之物或爲粗之物。例如，能夠使 用絞合7條外徑0.0 8 m m之導線（相當於A W G 3 2號，外徑 0.24mm )的絞合線。 第2圖係相對於捲繞有上述金屬箔膠帶13之無外層被 覆的高速差動傳輸電纜10a，顯示被外層被覆15覆蓋金屬 箔膠帶13之外側的高速差動傳輸電纜i〇b。高速差動傳輸 電纜1 Ob係針對利用外層被覆1 5加以被覆之構造以外的部 分’因爲實質上能夠作成與第1圖說明的構造同樣的構 造，故省略詳細說明。 外層被覆15也被稱爲套管，設置有包含金屬箔膠帶 1 3而用以保護整個電纜。此外層被覆1 5係使用擠出機以 擠壓成形聚氯乙嫌、聚乙烯或後述之聚胺甲酸酯樹脂與乙 烯-醋酸乙烯共聚合樹脂之混合樹脂等而加以擠壓成形，或 是能夠捲繞樹脂膠帶而加以形成。外層被覆1 5係電性絕緣 金屬泊膠帶13加以保護的同時，補強其機械強度，進一步 -12- 200908025 增強經得起彎曲等之強度。 金屬箔膠帶1 3之外圍被外層被覆所被覆之情形’金屬 箔膠帶1 3也可以使其金屬箔面成爲外側之方式來加以捲 繞。此情形下，藉由利用外層被覆1 5覆蓋，能夠予以保護 而使其具有耐久性。另外，使金屬箔1 3成爲外側之方式來 捲繞金屬箔膠帶1 3之情形，汲線1 4係配設於金屬箔膠帶 1 3之外側。而且，作成利用外層被覆1 5接觸於金屬箔面 之方式來按壓的形態。利用外層被覆1 5以被覆金屬箔膠帶 1 3之情形，金屬箔膠帶1 3也可以未必黏著於絕緣體1 2。 依照本發明所得的高速差動傳輸電纜10a、10b，其係 將相鄰如上所形成的多心電纜之2條電導體1 1作成一組， 設爲一信號線對。如第1圖及第2圖所示，信號線對係具 有至少2對以上之複數對（例如，5對之S 1〜S 5 )。而且， 將形成此等信號線對之一側信號線（Spl〜Sp5 )設爲正電 位信號用’將另一側信號線（S η 1〜S η 5 )設爲相反的負電 位信號用。另外’具有充裕之電導體1 1條數之情形，將各 信號線對s之間的電導體作爲接地線G，來減低相鄰之信 號線對S間的信號結合，使串音不發生之方式來進行。 於使用上述之高速差動傳輸電纜l〇a、l〇b的傳輸路徑 中’傳送側之情形’例如，於上述之信號線對S1中，利用 信號線Sp 1傳輸極性爲正位準之（+v 1 )信號，利用信號 線S η 1傳輸極性爲負位準之（-V 1 )信號。而且，接收側之 情形，藉由採取二者信號位準之差「（ +V 1 ) - ( -V 1 )」， 能夠接受2V1之位準信號。另外，雖然侵入傳輸路徑中之 200908025 外部雜訊係以與信號線Sp 1與Sn 1同相之方式來相加’但 是藉由在接收側採取信號差而被抵消。信號線對S係以將 複數對排成平行一列之形態而予以設置，各自之信號線對 (S 1〜S 5 )能夠個別傳送相互不同的信號。 配設於各信號線對S間之接地線G係設爲接地電位。 接地線G較佳爲挾住各信號線對（S 1〜S 5 )的兩側之方式 來予以配設，相對於信號線Sp與信號線Sn二者，形成電 性、物性相均衡之配置狀態。但是，因爲信號線對S不存 在，位於電纜兩端之信號線對S 1與S 5的外側也能夠省略。 另外，其他不影響信號線對S之形態下，例如，在設置信 號線群之配列間距數倍之距離上，也可以具備電源線等。 若考量能夠確保電性絕緣之距離，還有信號線Sp與 Sn之間的鍵結度時，電導體1 1之外徑爲0.18mm (相當於 AWG34號）之情形，形成信號線Sp、Sn及接地線G之電 導體1 1的配列間距P能夠設爲約〇.5mm。另外，絕緣體 1 2之被覆寬度D 1係使特性阻抗成爲既定値（例如，1 〇〇Ω ) 之方式來考量絕緣體12之電容率後而加以選擇。另外，具 有外層被覆1 5之情形，外層被覆之被覆寬度D2係被覆厚 度約爲0.2mm，內部之電導體1 1的粗度係依照絕緣體12 之被覆厚度，設爲約1.0mm〜3.0mm。 於上述之構造中，爲了增大特性阻抗，使電導體1 1之 直徑變細，或是增大絕緣體1 2之厚度，特性上較佳爲使絕 緣體1 2之厚度增加。相反的，爲了減少特性阻抗，使電導 體1 1之直徑變粗，或是縮小絕緣體1 2之厚度，特性上較 200908025 佳爲使電導體1 1之粗度增加。 另外，通常電纜之傳輸損失達5.0 dB/使用長度 許的。使用長度2m之情形，2_5dB/m將被容許。另 輸損失係根據使用頻率而有所不同’例如’ HDMI之 率8 2 5 Μ Η z下，使用絞合7條電導體1 1之線後且 0.18mm(AWG34號），將導體間距P作成〇_5mm’ 體12之厚度D1作成相同於導體間距P之〇.5mm。 將聚乙烯使用於絕緣體1 2之情形，傳輸損失係推定 〜2.0 d B 〇 另一方面，爲了使用如第5圖所示之極細同軸 簾狀電纜，且以〇.5mm形成相同於上述之導體間距 既定特性電阻，必須使中央導體之粗度作成絞合7 0.03mm (相當於AWG40號、外徑〇.〇9mm)之細徑 果，與上述同樣的使用頻率8 2 5 MHz之傳送損失成 〜5 dB/m，相較於本發明之情形，係成爲2倍的損失 方面，利用習知構造，爲了成爲相等於本發明申請 輸損失，簾狀電纜之寬度、厚度將增大，配線間隙將 操作性也將降低。 第3圖係說明有關金屬箔膠帶黏著之實施形 形。第3 ( A )圖係說明賦與根據本發明所得的黏著 與形態一例的圖形’第3 ( B )圖係說明汲線與金屬 之電性接觸與黏著狀態的圖形，第3 ( C )圖係針對 膠帶之黏著部與非黏著部加以說明的圖形。於圖中 表示黏著條紋、16a、16b係表示薄長條桿狀之黏著 係被容 外，傳 使用頻 外徑爲 將絕緣 而且， 爲1 ‘5 構造之 而得到 條外徑 。其結 爲4dB 。另一 案之傳 增大， 態的圖 劑之賦 箔膠帶 金屬箔 ，16係 條紋、 200908025 1 7係表示空隙、丨8係表示黏著面、丨9係表示非黏著面。 金屬箔膠帶1 3係如利用第1、2圖之構造例加以說明， 期望金屬箔膠帶1 3之金屬箔與電導體1 1間之間隔距離保 k 一疋’遍布電纜全長之特性阻抗予以均勻。無外層被覆 1 5之情形’較佳爲金屬箔膠帶丨3與絕緣體〗2相互黏著而 予以一體化。因此，黏著劑賦與在金屬箔膠帶1 3或絕緣體 1 2中任一黏著面。例如，能夠將聚酯系之黏著劑使用於黏 著劑。 金屬箔膠帶13與絕緣體12之黏著，其整面並無同樣 黏著之必要。因此，能夠以斑馬條紋狀、格子狀、水珠狀、 鋼板條紋狀等各種形態，將黏著劑塗布於其黏著面後而加 以黏著。然而，根據此等塗布形狀或塗布狀態，可能發生 各種問題。例如，使用顯示於第1、2圖之汲線1 4之情形， 期望使汲線1 4移動或不移動之方式而利用黏著劑加以固 定。但是在金屬箔膠帶1 3側塗布有黏著劑之情形，因爲黏 著劑通常可使用電絕緣性之物，有損害金屬箔膠帶1 3而與 汲線1 4電性接觸之虞。 第3 ( B )圖係顯示將汲線1 4接觸於金屬箔膠帶1 3之 金屬箔面的形態。如該圖所示，汲線1 4係以根據黏著劑之 塗布產生的黏著條紋20之寬度a黏著後而予以保持。於黏 著條紋20之間，黏著條紋1 6間形成有間隔b之空隙1 7，汲 線1 4係凹入此空隙1 7內之方式來彎曲後而電性接觸於金屬 箔膠帶13。因而，若空隙17之間隔b狹窄時，汲線14與金 屬箔膠帶13之接觸狀態將降低。還有，黏著條紋16之寬度a -16- 200908025 與空隙1 7之寬度b，若爲a/b S 2的話，得知無問題。 另外，如第3 ( C )圖所示，金屬箔膠帶1 3與絕緣體 1 2之黏著面1 8與非黏著面1 9黏著成斜向條紋狀之情形’ 例如，沿著非黏著面1 9 ( N -N線）折彎時，金屬箔膠帶於 非黏著面1 9成爲浮出之狀態，電纜之阻抗將改變。再者’ 於此狀態下重複予以折彎時，擔憂產生彎曲皺褶而於金屬 箔中發生斷裂。 若考量如上之事實時，無外層被覆且具有汲線之情 形，得知黏著劑之塗布形態係以塗布成如第3 ( A )圖所示 之習知之條紋鋼板（也稱爲花紋鋼板）的止滑鋼板圖案為 宜。第3(A)圖係顯示在所展開的金屬箔膠帶13之黏著 面，以條紋鋼板圖案形成黏著條紋1 6的例子。還有’無外 層被覆1 5且無汲線1 4之情形，金屬箔膠帶1 3與絕緣體 1 2連接的部分之整面最好鄕黏著，黏著劑塗布中任一種方 法皆可。 利用外層被覆1 5被覆金屬箔膠帶1 3之情形’因爲外 層被覆15按壓金屬箔膠帶13，無論是否將金屬箔膠帶13 黏著於絕緣體1 2皆可。此情形下，如第3 ( A )圖所示’ 黏著條紋1 6可以爲利用條紋鋼板圖案而黏著於絕緣體單 面的形態，也可以整面形成。 此條紋鋼板圖案係將相垂直的薄長條桿狀之黏著條紋 16a、16b予以交替配置，使整體向長邊方向或寬度方向傾 斜。例如，將黏著條紋1 6 a、1 6 b之一片寬度設爲約〇 · 5 m m、 將長度設爲約4.5 mm，利用任意之密度塗布於絕緣體或金 200908025 屬箔膠帶側之黏著面。藉由使用此條紋鋼板圖案之黏著條 紋，例如，將在第3 ( B )圖說明之「a/b」設爲約「1/8」 爲可能的，藉此，能夠使汲線與金屬箔予以充分接觸。另 外，也能夠使如第3 ( C )圖說明之直線狀非黏著面1 9不 生成之方式來進行，金屬箔膠帶1 3不會浮現條紋狀。 另外，近年來具備難燃性之尺度的要求爲高的，正尋 求一種合格於UL規格之垂直燃燒試驗VW- 1的硬度之難燃 性電纜。 第4圖係顯示提高根據本發明之電纜難燃性之構造例 的圖形。於顯示於第1圖之無外層被覆的電纜之情形，以 縱向附加之方式捲繞金屬箔膠帶1 3之重疊部分，其係根據 黏著以保持捲繞狀態程度之狹窄重疊量而予以形成。然 而，若金屬箔膠帶1 3之捲繞重疊量爲少的話，根據燃燒重 疊部分之黏著劑將熔解。而且，從此重疊部分，膠帶內側 之聚乙烯樹脂將氣化而漏出，於是此將燃燒而助長電纜之 延燒。 因而，如第4圖所示’期望擴大金屬箔膠帶13之捲繞 重疊部分。試驗之結果，藉由1·5層捲繞金屬箔膠帶13, 能夠抑制燃燒氣體之洩漏。因而’金屬箔膠帶1 3較佳爲 1 . 5層以上捲繞於絕緣體之外圍，將捲繞之重疊部分設爲 0.5捲以上。 另外，金屬箔膠帶1 3之金屬箔爲鋁箔之情形，孔洞張 開7 μ m，難燃性試驗將變得不合格’ 1 0 μ m以上之厚度爲必 要的。銅箔之情形，7μιη之厚度時，難燃性試驗爲合格的。 -18- 200908025 因而’爲了提高難燃性’較佳爲使用銅箔膠帶。 另外’於具有第2圖之外層被覆的電纜中，藉由將難 燃性物質使用於外層被覆材料，能夠提高難燃性。難燃性 之外層被覆，習知使用添加有鹵素系難燃劑之難燃聚乙烯 或聚氯乙烯樹脂，但是，基於環境問題，不含鹵素之無鹵 素的難燃性電纜之要求逐漸升高。於本發明中，使用聚胺 甲酸酯樹脂與乙烯-醋酸乙烯共聚物（EVA )樹脂之混合樹 脂（例如，參照日本專利特開2 0 0 8 - 1 1 7 6 0 9號公報）作爲 電纜之外層被覆，已實現電纜之難燃化。利用難燃性之被 覆覆蓋金屬箔膠帶13之情形，只要金屬箔膠帶13之一部 分重疊即可。 ^ 於爲了連接器連接等之終端形成之際，期望屏蔽導體 之金屬箔使用YAG雷射而加以切斷。還有，通常將c〇2 雷射使用於絕緣體部分之切斷。但是，若絕緣體爲透明或 自然色時，當利用使用YAG雷射切斷屏蔽導體之時，將可 能使絕緣體內部之導體予以劣化。另一方面，若將絕緣體 予以著色而使YAG雷射難以穿透時，下次利用C02雷射將 變得難以切斷絕緣體。 於本發明中，將碳黑添加於絕緣體中，期望將絕緣體 之顏色作成淡黑色。還有，碳黑之添加量較佳設爲約〇 · 5 wt % (0.4〜6重量％ )。若爲此程度之添加量的話，YAG雷 射不會對內部之導體造成影響，能夠僅切斷金屬箔膠帶。 另外，對於絕緣體，能夠確保因C02雷射所進行的切斷。 另外，於具有屏蔽導體之平整電纜之情形，與有無外 -19- 200908025 層被覆無關，若予以極端彎曲（最小彎曲半徑以下之彎曲） 時，將有於形成屏蔽導體之金屬箔膠帶的金屬箔中發生龜 裂或切斷之情形。因此，使電纜不會以既定之彎曲半徑以 下之半徑予以彎曲之方式來彎曲之位置上’期望具備一彎 曲限制手段，其係設定較金屬箔膠帶未切斷之最小彎曲半 徑爲大的彎曲半徑。 於本發明中，採用黏著等方式以將電纜不會彎曲至如 既定之曲率半徑以下之彎曲限制構件，預先設置於所假想 之預先彎曲位置。彎曲限制構件能夠利用圓筒、圓柱、半 圓筒、半圓柱之棒狀構件加以形成。還有，例如，相對於 電纜之9 0 °折彎，此等彎曲限制構件之彎曲面的半徑能夠設 定彎曲半徑約1 _ 5 m m ;相對於電纜之1 8 0。折彎，能夠設定 彎曲半徑約2.5 m m。 【圖式簡單說明】 第1圖係說明根據本發明之高速差動傳輸電續（無外 層被覆）之構造例的圖形。 第2圖係說明根據本發明之高速差動傳輸電續（有外 層被覆）之構造例的圖形。 第3圖係說明有關本發明中之金屬箔膠帶黏著之實施 形態的圖形。 第4圖係δ兌明針對根據本發明之局速差動傳輸電纜之 難燃化的圖形。 第5圖係說明習用技術的圖形。 -20- 200908025 【主要元件符號說明】 1 中 心 導 體 2. 電 介 質 層 3 皮 層 4a、 4b 信 號 線 5a、 5b 汲 線 6 外 部 導 體 7 套 管 層 8 差 動 電 纜 9 簾 狀 電 纜 10a 、10b 筒 速 差 動 傳 輸 電 纜 11 電 導 體 12 絕 緣 體 13 金 屬 箔 膠 帶 13a 金 屬 箔 13b 塑 膠 基 材 13c 黏 著 劑 14 汲 線 15 外 層 被 覆 16 黏 著 條 紋 16a 、16b 薄 長 條 桿 狀 之 黏 著條紋 17 空 隙 18 黏 著 面 19 非 黏 著 面 -21- 200908025 20 黏著條紋 S 信號線對 S p、S n 信號線 G 接地線 -22200908025 IX. Description of the Invention: [Technical Field] The present invention relates to a high-speed differential transmission cable for flat-shaped transmission of digital data and the like at high speed. [Prior Art] In the case where digital data is to be transmitted at a high speed, the time until the data signal is shifted from the high level to the low level (or from the low level to the high level) (so-called migration time) must be shortened. In shortening the migration time, the signal amplitude can be reduced. However, once the signal amplitude is reduced, there will be a problem that the external noise becomes weak. Therefore, it is conventional to use a pair of signal lines to transmit signals of inverted bits, and on the data receiving side, the difference of the transmitted signals is used as a differential transmission method of data. This method outputs a signal difference of the inverse phase on the receiving side of the transmission signal. Even if the signal amplitude on the transmission side is reduced, the signal amplitude of this differential output on the receiving side is doubled. In the transmission path, the incoming noise system is identically overlapped on a pair of signal lines to cancel each other. The signal transmission system described above is a low voltage differential signal (LVDS) method in which a small voltage change differential signal is used to transmit a data signal on a pair of wires, thereby achieving high speed, low power consumption, and low noise. Such a signal transmission method is effectively used in an HDMI (High-Definition Multimedia Interface) which is an integrated interface for transmitting image signals, sound signals, and control signals by using a cable, and an interface connecting a computer and a hard disk. Serial ATA (Advanced Technology Attachment). 200908025 According to the use as described above, a cable disclosed in Patent Document 1 is used for transmitting a high-speed differential signal 'for example'. This cable 'is, for example, a so-called curtain cable in which a plurality of differential cables as shown in Fig. 5 are arranged in a curtain shape. The curtain cable 9 is a differential cable 8 which is shielded as shown in a pair of signal lines shown in FIG. 5(A), and the plurality of bars are arranged in parallel in a row as shown in FIG. 5(B). Adjacent differential cables are formed by heat fusion between each other. Each of the differential cables 8 is formed by covering the center conductor 1' with the dielectric layer 2 and providing a skin layer 3 on the periphery thereof to form a signal line, and arranging the two signal lines (4a, 4b) in parallel. Next, on both outer sides of the signal lines 4a and 4b arranged in parallel, twist lines 5a, 5b are disposed. Then, while maintaining the configuration, the outer conductor 6 made of a metal foil tape is wound around the outer periphery thereof, and the outer side of the sleeve layer 7 is covered to form a final structure. The center conductor 1 is formed as a stranded wire having an outer diameter of 0.609 mm (AWG No. 24) by, for example, twisting seven silver-plated soft copper wires. The dielectric layer 2 was formed by coating a porous PTFE (tetrafluoroethylene resin) tape having a thickness of 0.37 mm on the periphery of the center conductor 1. The skin layer 3 is formed of PEP (tetrafluoroethylene-hexafluoropropylene copolymer resin) having a thickness of 〇. 9 mm, covering the outside of the dielectric layer 2. The diameters of the rifling wires 5 a and 5 b are thinner than those of the center conductor 1 and are twisted by 7 silver-plated soft copper wires to form a stranded wire having an outer diameter of 0.306 mm (AWG No. 30). The outer conductor 6 is formed by winding a metal vapor deposition tape in a spiral or longitudinal direction. The sleeve layer 7 is formed by using a non-halogen flame retardant olefin resin having a thickness of 0.25 mm, and the outer diameter of the long diameter side is made 4.3 mm, and the 200908025 sleeve layer is arrayed in parallel in a row and the long diameter side is The sides are melted together and integrated. Patent Document 1: Japanese Patent Laid-Open Publication No. H02-3001 9 2 1 SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION i With the development of a plasma display or a liquid crystal display, as a machine The signal transmission cable used for the wiring material will also become longer. Now, there will be about dozens of wiring. The cable of length 111 is, for example, intended to be wired to a length of 2 m or more. In this case, the problem of 'transmission loss will occur' to simply lengthen the existing cable. This will make it difficult. For example, in the case where the signal transmission cable is used in the high frequency region, as the frequency becomes higher, the dielectric loss of the dielectric layer covered with the signal line also becomes larger. In particular, the frequency of use of H D ΜI is above 8 2 5 MHz, and the transmission loss in this case will become a factor that cannot be ignored. In order to avoid an increase in transmission loss of the signal transmission cable, it is necessary to increase the thickness of the center conductor or the like, and in the curtain cable disclosed in Fig. 5, the cable diameter will become large. Therefore, the softness is lowered, and the operability is deteriorated, and the problem of the wiring gap is also revealed. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a flat high-speed differential transmission cable composed of a plurality of signal line pairs which are low in loss without increasing a cable diameter. The high-speed differential transmission cable obtained according to the present invention is a signal line pair that is differentially transmitted by taking two electric conductors as a group, and a plurality of the 200908025 signal line pairs are arranged in a flat state. a high-speed differential transmission cable coated with an insulating resin; the electrical conductors composed of a plurality of single-core wires or stranded wires are arranged in parallel at a predetermined interval, and are integrally formed by an insulator composed of an insulating resin. The coated 're-longitudinal metal foil tape is attached to cover the periphery of the insulator. Further, it is also possible to cover the periphery of the metal foil tape with an outer layer made of an insulating resin. Ground lines are arranged between the signal line pairs of the complex array to reduce the coupling between the signal line pairs. Further, the twisted wire is electrically placed in contact with the metal foil tape, and the metal foil tape is easily grounded. Further, the interval between the plurality of electric conductors is set to a narrow pitch of 0.5 mm or less, so that a predetermined transmission characteristic can be obtained. Further, the insulator and the metal foil tape are adhered by an adhesive, and the desired adhesive is applied to the insulator or the foil tape by a pattern of a striped steel plate. Further, the metal foil tape is wound around the insulator in 1.5 or more layers and is flame retardant. The outer periphery of the metal foil tape is covered with the outer layer coating, and the outer layer is coated with a mixed resin of a polyurethane resin and an ethylene-vinyl acetate copolymer resin to make it flame-retardant. Further, by adding 0.4% by weight to 0.6% by weight of carbon black to the insulator, it is easy to process the metal foil by the YAG laser. Further, it is also possible to provide a structure in which a bending restricting member having a bending radius larger than a minimum bending radius which is not cut by the metal foil tape is attached to a position at which the cable is bent. [Effects of the Invention] According to the present invention, it is possible to realize a high-speed differential transmission cable with low loss of 200908025 without thickening the diameter of the signal line, even in the case where the wiring distance in the electronic equipment room or the electronic device becomes long. The suppression of loss increases and the signal transmission at high speed is effectively performed. [Embodiment of the Invention] An embodiment of the present invention will be described by way of illustration. The second figure shows the cable profile without the outer cover, and the second figure shows the cable profile with the outer cover. In the figure, '10a and 1'b denote high-speed differential transmission cable, i1 denotes an electrical conductor, 12 denotes an insulator, 13 denotes a metal foil tape, 14 denotes a rifling, and 15 denotes an outer coating. ' sp and S ϋ denote signal lines, S denotes signal line pairs, and g denotes ground lines. The high-speed differential transmission cable 10a of the present invention is formed by arranging a plurality of electric conductors 1 1 in a row at predetermined intervals as shown in the figure. The plurality of electrical conductors 1 1 are covered with an insulator 1 2 made of an insulating resin, and the metal foil tape 13 as a shield conductor is wound in the longitudinal direction of the cable and wound around the outer side of the cable. Further, if necessary, the twisted wire 14 is electrically connected to the metal foil tape 13 so as to be disposed between the insulator and the insulator. Further, the twist line 14 is preferably disposed on one side or both sides of the side edge of the cable. The electric conductor 11 can be made of a good conductor such as copper or aluminum or a single-core wire or a stranded wire of tin or silver on which the desired electrical conductor 1 1 is formed into a circular shape which is almost equal in length and width. Linear. In the flat cable, although a flat conductor is used, the coupling between signals for differential transmission can be enhanced by using a circular wire conductor. Further, by enhancing the weighing between the signals, the eddy current induced by the shield conductor (metal case tape 13) and thus the Joule loss caused by the eddy current can be reduced, which is regarded as low attenuation. 200908025 In addition, from the viewpoint of flexibility, the electrical conductor U-based stranded wire is better than the single-core wire. For example, it is possible to use a stranded wire of seven wires having an outer diameter of 0.06 mm (corresponding to AWG No. 34 and outer diameter 〇.l8 mm). The conductance system is arranged in parallel in a row on the same plane with a predetermined distance P, and is integrally covered with an insulator 12 obtained by extrusion molding of an insulating resin to form a flat multi-core insulated cable shape. The insulator 1 2 electrically insulates the electrical conductors 1 and functions between the electrical conductors 1 1 and the metal foil tape for use in a high frequency region, and functions as a capacitor for forming electrostatic coupling. Therefore, the insulator 12 is also referred to as a dielectric, and its dielectric tangent (tan5) and permittivity (?) are also parameters of the characteristics of the left and right transmission cables. From the viewpoint of reducing dielectric loss, it is desirable that the dielectric tangent of the insulator 12 is as small as possible, and in order to make the diameter of the cable thinner, it is desirable that the capacitance ratio is as small as possible. Therefore, regardless of the dielectric tangent and the permittivity of the insulator 12, the lower transmission loss is small, and the high-frequency signal can be efficiently transmitted. However, the combination of the dielectric material and the shape must also be considered in connection with the machine and ensuring the specified characteristic impedance. In the present invention, for example, a polyolefin resin is used for forming the insulating resin of the insulator 1 2, and for example, a polyethylene resin or the like can be used. The dielectric tangent of polyethylene resin is about 4xl〇-4, and the permittivity is 2.3~24, which is smaller than that of polyethylene resin (for example, the dielectric tangent of PET is about 2χ1〇-3, and the permittivity is about 2·9~3.0) It is a better material. Further, the insulator 12 is expected to be extruded using an extruder with respect to a plurality of electrical conductors 1 1 arranged at predetermined intervals. -10-200908025 The case where the insulator 12 is extruded. The upper and lower planes of the insulator 12 are formed so as not to form a flat surface such as a depression between the electrical conductors 11. Thereby, the interval between the respective electrical conductors 1 1 and the metal foil tape 13 wound around the periphery of the insulator 12 can be made constant, and the impedance of uniform characteristics can be obtained. The metal foil tape 13 is formed in such a manner that a predetermined electrostatic capacitance distribution is formed between the signal lines in the electric conductor 11 as described above so that a predetermined characteristic impedance can be obtained. Further, the metal case tape 13 is provided on the periphery of the insulator 12, and has a function of preventing the intrusion of noise signals (noise) from the outside or leaking signals to the outside. This metal foil tape 13 is formed by bonding a metal foil 3a such as aluminum or copper to a plastic substrate 13b such as polyethylene terephthalate (PET) or vapor deposition. The metal foil 13a and the plastic base material 13b can be used in a thickness of several μm to several tens of μηα. The overall thickness of the metal foil tape 13 can be 0.01 mm to 0_05 mm. For example, a copper foil having a thickness of 9 μm can be used as the metal foil 13a, and a PET having a thickness of 6 μm can be used as the plastic substrate 13b, and a CuPET tape having a thickness of 15 μm can be used. The metal foil tape 13 has a metal foil surface as an inner side, is longitudinally attached to the insulator 12, and is bent at a width of the insulator 12, and at least the overlapping portion thereof is adhered and fixed by an adhesive 1 3 c. By making the metal foil surface of the metal foil tape 13 as the inner side, since the metal foil does not expose the outer surface of the cable, it is possible to have a certain range of durability as a cable even if the outer layer is not covered. In addition, since the metal foil tape 13 must be impedance integrated with the electrical conductor 1 1 , the isolation distance from the electrical conductor 11 must be fixed. For this reason, the metal foil tape 13 is preferably firmly attached to the insulator 12 without covering the outer periphery of the metal foil tape 13 with the outer covering 15. However, there is no need to apply the adhesive to the entire surface of the 200908025 without a gap. As will be described later, if the metal foil tape 13 is attached in a manner that does not appear, the adhesive may be partially coated in a stripe shape or the like. The metal foil tape 13 itself is easily grounded, and the twisted line j 4 is not necessarily necessary. However, by using the twisting wire 14, it is easy to connect the grounding of the metal foil tape 13 and if necessary, it is provided. The twisted wire i 4 is provided separately from the above-described electrical conductor 1 1 and is disposed on one side or both sides of the side edge of the cable by the insulator 12 and the metal foil tape 13 . Further, the same material as the electric conductor 1 1 may be used for the twisted wire 14 or may be a thinner or thicker one than the electrical conductor 1 1 . For example, it is possible to use a stranded wire of seven wires having an outer diameter of 0.08 m (corresponding to A W G 3 No. 2 and an outer diameter of 0.24 mm). Fig. 2 shows a high-speed differential transmission cable iab covered with the outer layer covering 15 on the outer side of the metal foil tape 13 with respect to the high-speed differential transmission cable 10a having the outer layer covered with the metal foil tape 13 wound thereon. In the high-speed differential transmission cable 1 Ob, the portion other than the structure covered by the outer layer covering 15 is substantially the same as the structure described in the first embodiment, and therefore detailed description thereof will be omitted. The outer cover 15 is also referred to as a sleeve and is provided with a foil tape 13 to protect the entire cable. Further, the layer coating 15 is extruded by using an extruder to extrude polyvinyl chloride, polyethylene or a mixed resin of a polyurethane resin to be described later and an ethylene-vinyl acetate copolymer resin, or It can be formed by winding a resin tape. The outer layer is covered with a 5 5 electrically insulating metal tape 13 to protect it while reinforcing its mechanical strength, and further -12-200908025 to enhance the strength of bending and the like. In the case where the outer periphery of the metal foil tape 13 is covered with the outer layer coating, the metal foil tape 13 may be wound such that the metal foil surface is outward. In this case, by covering with the outer layer covering 15, it can be protected to have durability. Further, in the case where the metal foil tape 13 is wound so that the metal foil 13 is outside, the twisted wire 14 is disposed on the outer side of the metal foil tape 1 3 . Further, a form in which the outer covering 15 is brought into contact with the surface of the metal foil is formed. In the case where the outer layer is coated with 15 to cover the metal foil tape 1 3, the metal foil tape 13 may not necessarily adhere to the insulator 12. The high-speed differential transmission cables 10a, 10b obtained in accordance with the present invention are formed as a pair of signal conductors by arranging two electrical conductors 1 1 adjacent to the multi-core cable formed as described above. As shown in Figs. 1 and 2, the signal line pair has at least two pairs of complex pairs (for example, five pairs of S 1 to S 5 ). Further, one of the signal line pairs forming one of the signal line pairs (Sp1 to Sp5) is used as a positive potential signal for 'the other side signal line (S η 1 to S η 5 ) to be set to the opposite negative potential signal. In addition, in the case of having a sufficient number of electrical conductors, the electrical conductor between each signal line pair s is used as the grounding line G to reduce the signal combination between adjacent signal line pairs S, so that crosstalk does not occur. Way to proceed. In the case of using the above-described high-speed differential transmission cables 10a, 10b, the 'transmission side', for example, in the above-mentioned signal line pair S1, the polarity of the transmission is positive by the signal line Sp1 ( The +v 1 ) signal transmits a (-V 1 ) signal of a negative polarity using the signal line S η 1 . Further, in the case of the receiving side, it is possible to accept the level signal of 2V1 by taking the difference between the signal levels "(+V 1 ) - ( -V 1 )". Further, although the 200908025 external noise system in the intrusion transmission path is added in the same manner as the signal lines Sp 1 and Sn 1 'but is canceled by taking the signal difference on the receiving side. The signal line pair S is provided in a form in which a plurality of pairs are arranged in parallel, and each of the signal line pairs (S 1 to S 5 ) can individually transmit signals different from each other. The ground line G disposed between the signal line pairs S is set to the ground potential. The grounding wire G is preferably disposed so as to be caught on both sides of each of the signal line pairs (S 1 to S 5 ), and is configured to be electrically and physically balanced with respect to both the signal line Sp and the signal line Sn. status. However, since the signal line pair S does not exist, the signal line pairs S 1 and S 5 located at both ends of the cable can be omitted. Further, in the case where the signal line pair S is not affected, for example, a power supply line or the like may be provided at a distance several times the arrangement pitch of the set signal line group. If it is considered that the distance between the electrical insulation can be ensured, and the degree of bonding between the signal lines Sp and Sn, the outer diameter of the electrical conductor 1 is 0.18 mm (corresponding to AWG No. 34), the signal lines Sp, Sn are formed. The arrangement pitch P of the electrical conductors 1 1 of the grounding wire G can be set to about 〇5 mm. Further, the coating width D 1 of the insulator 12 is selected so that the specific resistance is a predetermined value (for example, 1 〇〇 Ω), and the permittivity of the insulator 12 is considered. Further, in the case where the outer layer coating 15 is provided, the coating width D2 of the outer layer coating is about 0.2 mm, and the thickness of the inner electric conductor 1 is about 1.0 mm to 3.0 mm in accordance with the thickness of the covering of the insulator 12. In the above configuration, in order to increase the characteristic impedance, the diameter of the electric conductor 1 1 is made thinner, or the thickness of the insulator 12 is increased, and the thickness of the insulator 1 2 is preferably increased. Conversely, in order to reduce the characteristic impedance, the diameter of the electric conductor 11 is made thicker, or the thickness of the insulator 12 is made smaller, and the characteristics are better than that of the 200908025 to increase the thickness of the electric conductor 11. In addition, the transmission loss of the cable is usually 5.0 dB/length of use. In the case of a length of 2 m, 2_5 dB/m will be tolerated. The other loss is different depending on the frequency of use. For example, the HDMI rate is 8 2 5 Μ Η z, and the conductor pitch P is made by twisting 7 wires of the electric conductor 1 1 and 0.18 mm (AWG No. 34). The thickness D1 of the body _5 mm' body 12 is made equal to 导体5 mm of the conductor pitch P. In the case where polyethylene is used for the insulator 12, the transmission loss is estimated to be ~2.0 d B. On the other hand, in order to use the ultra-fine coaxial curtain cable as shown in Fig. 5, the same conductor as described above is formed at 〇5 mm. For the predetermined characteristic resistance, the thickness of the center conductor must be made to be a small diameter of 7 0.03 mm (corresponding to AWG No. 40, outer diameter 〇. 〇 9 mm), and the same transmission frequency of 8 2 5 MHz is used. ~5 dB/m, compared to the case of the present invention, in terms of loss of 2 times, the width and thickness of the curtain cable are increased in order to be equivalent to the loss of the application of the present invention, and the wiring gap is increased. The operability will also be reduced. Figure 3 is a diagram showing the implementation of the adhesion of the metal foil tape. Fig. 3(A) is a view showing a pattern of an example of adhesion and form obtained according to the present invention. Fig. 3(B) shows a pattern of electrical contact and adhesion between a squall line and a metal, Fig. 3 (C) A figure that describes the adhesive portion and the non-adhesive portion of the tape. In the figure, the adhesive stripes are shown, 16a and 16b are thin strip-shaped adhesives, and the outer diameter of the transmission is insulated, and the outer diameter of the strip is 1 '5. Its knot is 4dB. In another case, the film is added. The foil is coated with metal foil, 16 series stripes, 200908025 1 7 is the void, 丨8 is the adhesive surface, and 丨9 is the non-adhesive surface. The metal foil tape 13 is described by using the structural examples of Figs. 1 and 2, and it is desirable that the distance between the metal foil of the metal foil tape 13 and the electrical conductor 1 is kept constant. In the case where no outer layer is coated, it is preferable that the metal foil tape 3 and the insulator 2 are adhered to each other and integrated. Therefore, the adhesive is imparted to any of the adhesive faces in the metal foil tape 13 or the insulator 12. For example, a polyester-based adhesive can be used for the adhesive. The metal foil tape 13 is adhered to the insulator 12, and the entire surface thereof does not have the same adhesion. Therefore, the adhesive can be applied to the adhesive surface in various forms such as a zebra stripe shape, a lattice shape, a water droplet shape, or a steel stripe shape, and then adhered. However, depending on such coating shape or coating state, various problems may occur. For example, in the case of the first line 1 shown in Figs. 1 and 2, it is desirable to fix the twist line 14 by means of an adhesive so as not to move or move. However, the adhesive is applied to the side of the metal foil tape 13 because the adhesive can usually be electrically insulating, and the metal foil tape 13 is damaged to be in electrical contact with the twisted wire 14. The third (B) diagram shows the form in which the twisted wire 14 is brought into contact with the metal foil surface of the metal foil tape 13 . As shown in the figure, the twist line 14 is held by being adhered to the width a of the adhesive strip 20 produced by the application of the adhesive. Between the adhesive stripes 20, the gaps 16 between the adhesive stripes 16 are formed with a gap b, and the ridges 14 are recessed into the gaps 17 to be electrically connected to the metal foil tape 13. Therefore, when the interval b of the gaps 17 is narrow, the contact state of the twisted wires 14 with the metal foil tape 13 is lowered. Further, the width a - 16 - 200908025 of the adhesive strip 16 and the width b of the gap 17 are ab = 2 and it is known that there is no problem. Further, as shown in the third (C) diagram, the adhesion surface 18 of the metal foil tape 13 and the insulator 12 adheres to the non-adhesive surface 19 in a diagonal stripe shape. For example, along the non-adhesive surface 19 When the N-N line is bent, the metal foil tape becomes floating on the non-adhesive surface 19, and the impedance of the cable changes. Further, when the bending is repeated in this state, it is feared that the wrinkles are generated and the metal foil is broken. When considering the above facts, there is no outer layer coating and a twisted wire, and it is known that the coating form of the adhesive is applied to a conventional striped steel plate (also referred to as a tread steel plate) as shown in Fig. 3 (A). A slip-resistant steel plate pattern is preferred. Fig. 3(A) shows an example in which the adhesive strips 16 are formed in a stripe steel sheet pattern on the adhesive surface of the unfolded metal foil tape 13. Further, in the case where there is no outer layer covering 15 and no twist line 14, the entire surface of the portion where the metal foil tape 13 and the insulator 12 are joined is preferably adhered, and any of the adhesive coating methods may be used. In the case where the outer covering layer 15 is covered with the metal foil tape 1 3, the metal foil tape 13 is pressed by the outer layer covering 15 regardless of whether or not the metal foil tape 13 is adhered to the insulator 1 2 . In this case, as shown in Fig. 3(A), the adhesive streaks 16 may be adhered to one surface of the insulator by the stripe steel sheet pattern, or may be formed over the entire surface. This striped steel plate pattern alternately arranges the thin strip-shaped adhesive strips 16a and 16b which are perpendicular to each other so as to be inclined in the longitudinal direction or the width direction as a whole. For example, one of the adhesive stripes 16 a and 16 b is set to have a width of about 〇 5 m m and a length of about 4.5 mm, and is applied to the insulator or gold 200908025 on the side of the foil tape by an arbitrary density. By using the adhesive stripe of the stripe steel sheet pattern, for example, it is possible to set "a/b" described in the third (B) diagram to about "1/8", whereby the twisted wire and the metal foil can be formed. Give full contact. Further, it is also possible to carry out the method in which the linear non-adhesive surface 19 described in the third (C) diagram is not formed, and the metal foil tape 13 does not appear striped. In addition, in recent years, the demand for the scale of flame retardancy is high, and a flame-retardant cable which is qualified for the hardness of the vertical burning test VW-1 of the UL specification is being sought. Fig. 4 is a view showing a configuration example for improving the flame retardancy of the cable according to the present invention. In the case of the cable which is not covered with the outer layer shown in Fig. 1, the overlapping portion of the metal foil tape 13 is wound in a longitudinal direction, and is formed by adhering to a narrow overlap amount to maintain the winding state. However, if the amount of winding overlap of the metal foil tape 13 is small, the adhesive according to the burning overlap portion will be melted. Further, from this overlapping portion, the polyethylene resin inside the tape is vaporized and leaks, so that it will burn to promote the burning of the cable. Therefore, as shown in Fig. 4, it is desirable to enlarge the winding overlapping portion of the metal foil tape 13. As a result of the test, the metal foil tape 13 was wound by a layer of 1.5, and the leakage of the combustion gas was suppressed. Therefore, the metal foil tape 1 3 is preferably 1.5 or more layers wound around the periphery of the insulator, and the overlap portion of the winding is set to 0.5 or more. Further, in the case where the metal foil of the metal foil tape 13 is an aluminum foil, the hole is opened by 7 μm, and the flame retardancy test becomes unacceptable. A thickness of 10 μm or more is necessary. In the case of copper foil, the flame retardancy test was acceptable when the thickness was 7 μm. -18- 200908025 Therefore, it is preferable to use a copper foil tape in order to improve flame retardancy. Further, in the cable having the outer layer covered in Fig. 2, the use of the inflammable substance in the outer covering material can improve the flame retardancy. The flame retardant outer layer is coated. It is known to use a flame retardant polyethylene or a polyvinyl chloride resin to which a halogen-based flame retardant is added. However, the halogen-free halogen-free flame-retardant cable is gradually required to rise due to environmental problems. . In the present invention, a mixed resin of a polyurethane resin and an ethylene-vinyl acetate copolymer (EVA) resin is used as a cable (for example, refer to Japanese Patent Laid-Open Publication No. Hei 2 0 0 8 - 1 1 7 6 9). The outer layer is covered, and the cable is hardly ignitable. In the case where the metal foil tape 13 is covered with a flame retardant coating, it is sufficient that one of the metal foil tapes 13 is partially overlapped. ^ When a terminal such as a connector is formed, it is desirable that the metal foil of the shield conductor is cut using a YAG laser. Also, a c〇2 laser is usually used for the cutting of the insulator portion. However, if the insulator is transparent or natural, when the shield conductor is cut by using a YAG laser, the conductor inside the insulator can be deteriorated. On the other hand, if the insulator is colored to make it difficult for the YAG laser to penetrate, it will be difficult to cut the insulator by the CO 2 laser next time. In the present invention, carbon black is added to the insulator, and it is desirable to make the color of the insulator pale black. Further, the amount of carbon black added is preferably set to about 5% by weight (0.4 to 6% by weight). If this amount is added, the YAG laser does not affect the internal conductor and can cut only the foil tape. In addition, it is possible to ensure the cutting by the CO 2 laser for the insulator. In addition, in the case of a flat cable having a shielded conductor, regardless of the presence or absence of the outer layer 19-200908025, if it is extremely bent (bending below the minimum bend radius), there will be a metal foil of the metal foil tape forming the shield conductor. Cracking or cutting in the middle. Therefore, it is desirable to have a bending restriction means for the cable to be bent in such a manner that the cable is not bent at a radius below a predetermined bending radius, which is set to a bending radius larger than the minimum bending radius of the metal foil tape which is not cut. . In the present invention, the bending restricting member which is not bent to a predetermined radius of curvature or less by means of adhesion or the like is previously set in the imaginary pre-bending position. The bend restricting member can be formed by a rod-shaped member of a cylinder, a cylinder, a semi-cylindrical, or a semi-cylindrical shape. Also, for example, the radius of the curved surface of the bending restricting member can be set to a bending radius of about 1 _ 5 m m with respect to the 90° bend of the cable; 180 Ω with respect to the cable. Bend, you can set the bending radius to about 2.5 m. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a configuration example of a high-speed differential transmission electric power (without outer layer coating) according to the present invention. Fig. 2 is a view showing a configuration example of a high-speed differential transmission electric power (with outer layer coating) according to the present invention. Fig. 3 is a view for explaining an embodiment of the adhesion of the metal foil tape in the present invention. Fig. 4 is a graph showing the flammability of the differential transmission cable according to the present invention. Figure 5 is a diagram illustrating a conventional technique. -20- 200908025 [Description of main component symbols] 1 Center conductor 2. Dielectric layer 3 Cortex 4a, 4b Signal line 5a, 5b 汲 Line 6 External conductor 7 Casing layer 8 Differential cable 9 Curtain cable 10a, 10b Tube speed difference Transmission cable 11 Electrical conductor 12 Insulator 13 Metal foil tape 13a Metal foil 13b Plastic substrate 13c Adhesive 14 Twisted wire 15 Outer coating 16 Adhesive stripes 16a, 16b Thin strip-shaped adhesive stripes 17 Void 18 Adhesive surface 19 Non-adhesive Face-21- 200908025 20 Adhesive stripe S Signal line pair S p, S n Signal line G Ground line -22