201239901 六、發明說明： 【發明所屬之技術領域】 本發明係關於用於高速數位信號等信號傳送之多心作 號纜線與其製造方法。 【先前技術】 因為資訊通信技術之進展，通信纜線之使用頻率帶域 已經擴展至GHz帶。此外，在使適合於將電腦與顯示器接 續之介面規格用之DVI纜線等係使用2條之纜線之差動信 號傳送已經成為主流。此差動信號傳送係以將使相位相異 1 80度之信號同時輸入2條之纜線後發送並在接收側差分合 成者而可提高輸出並具有雜訊除去機能。 然而，有以2條之纜線之信號傳送之延遲時間差導致 之k號劣化之問題。因此，例如，於專利文獻1有揭示將 剖面形狀與長度相同之2條之同軸纜線成對使用、藉由個 別之同軸纜線係從同一纜線切出等來減低延遲時間差。此 外’於專利文獻2有揭示在被覆電線之製造於絕緣體使用 敗樹脂、且對導體被覆絕緣體時之拉伸平衡比（DRB )係使 為1 · 0程度。 先前技術文獻 專利文獻 專利文獻1:曰本特開2004-1 19060號公報 專利文獻2 :國際公開第2005/052015號公報 201239901 【發明内容】 [發明欲解決之課題] 缆線之延遲時間差係以纜線之物理長度、缆線之 體之介電常數決定，若在此等成對之2條之料相同，= 遲時間差會減低。然而，於在纜線之製造，將導體（同轴 纜線之中心導體）之周圍以絕緣體被覆時，特別是中 體為由i線構成之場合’ ^中心導體與絕緣體之間會有間 隙產生。&間隙係在纜線之長度方向非一 有變動產生。因此，會有在鏺绩具痒+ 常數 之問題。 長度方向延遲時間差變動 本發明係鑑於上述之實狀而為者，以提供減少中 體與絕緣體之間之間隙且在I線長度方向之延遲時間差之 變動減低之多心信號I線與其製造方法為目的。 [解決課題之手段] 本發月之多心h號I線係一種收納複數條將由播線構 成之中心導體以絕緣體被覆之同轴I線之多心信號I線， 其特徵在於：前述同軸I線之中心導體與絕緣體之密著力 (拉拔力/導體刮面積）為120*10-3(N/mm2)以上。另外， 前述中心導體係與AWG34相當或以上之細撚線，前述絕緣 體係氟樹脂。此外，以前述複數條之同軸纜線成為差動傳 送之對之同軸纜線之間係鄰接配置較理想。 此外’本發明之多心信號縱之製造方法係一種收納複 數條將由撚線構成之中心導體以絕緣體被覆之同軸纜線之 多心信號纜線之製造方法，於前述中心導體將前述絕緣體 4 201239901 以拉伸平衡比1.2以上拉伸，使前述同軸纜線之中 絕緣體之密著力（拉拔力/導體剖面積）〇* 、 L7 μ 〇 、N/IW) [發明之效果] 根據本發明’可減少中心導體與絕緣體之間之間隙 其結果，減低在纜線長度方向之延遲時間差之㈣ 延遲時間差之變動抑制為4〇ps/m以下。 將 【實施方式】 以圖說明本發明之實施之形態。圖1係說明本發 做為對象多心信號魔線之一例之圖 係表示同減線，6係表示電源信 係表示控制用之瘦線，8係表示遮蔽導體，9係表示護套 10係表示中心、導體’㈣表示絕緣體，12係表示外部導體， 13係表示外部覆蓋層。 本發明之所謂多心信號鏡線係指將傳送高速數位信號 =複數條之同軸纜線2a〜5b集束1共通之遮蔽導體8 ，，、心將其外側以護套9覆蓋而成之多心信號境線。另外， :為除了同軸纔線2a〜5b以外亦包含其他魔線，例如電源 之纜線6或控制用之纜線7等之複合纜線來構成亦可。 同轴徵線2a〜5b係使用例如將由槪線構成之中心導體 :絕緣體u覆蓋’於絕緣體u之外周配置外部導體12, 、外側以外部覆蓋層13被覆之構成者。中心、導體1〇係 用例如鑛錫軟銅線，將外徑0.05mm之素線7條樵合，做 5 201239901 為外徑0.15mm ( 0.0137mm2與AWG# 36相當）之中心導 體，或將外徑0.03mm之素線7條撚合，做為外徑〇 〇9mm (0.0049mm2與AWG # 40相當）之中心導體。 於絕緣體11係可使用氟樹脂，例如FEp、pFA。絕緣 體11之厚度與外徑係為了獲得既定之特性阻抗（5〇Ω )而 在中〜導體外徑〇. 15mm之場合為〇· 13mm厚、絕緣體外徑 〇.4lmm ’在中心導體外徑〇 〇9mm之場合為〇 75mm厚絕 緣體外徑0.24mm。 外部導體12係將與於中心導體1〇使用之素線導體相 同程度之粗度之裸銅線（軟銅線或銅合金線）或鍍銀或鍍 錫軟銅線或銅合金線於絕緣體n之外周以橫捲或編組構造 配置而形成。此外’為了使遮蔽機能向上，使為併設金屬 箔帶之構造亦可。外部覆蓋層13係將氟樹脂等樹脂材擠製 成形或將PE帶等樹脂捲繞而形成。 共通之遮蔽導體8係可使用於樹脂膜將鋁或銅蒸著之 導體’石帶°此導體箔帶係重複部分以帶寬之1 /8〜2/3捲繞 為螺旋狀’其捲節距係大約3mm〜60mm。 5蒦套9係以擠製成形形成，可使用PE、EVA、PU等樹 脂。 本發明係以於上述之多心信號纜線中信號傳送用之同 轴纖線2a〜5b之由撚線構成之中心導體1 0與絕緣體1 1之 密著力（拉拔力/導體剖面積）為120*10·3 ( N/mm2)以上 為特徵。密著力大即係中心導體10與絕緣體11之接觸狀 態填密’亦即’中心導體10與絕緣體11之間之間隙G較 6 201239901 -r fis. i u 少。若中心 ，一 * A i间炙間隙G敉少，纜綠 之在長度方向之介電常數之蠻叙+嫩， Λ 雙動亦變少。其結果，可使複 數條之同軸纜線間之較小。另认 λ ^ 平又j 另外’相對於中心導體面積 (mm2)，可以從絕緣體j i杈扑 _ m拔中心導體10需要之力（N) 表示。 絕緣體11雖係、於中心導體10之外Μ擠製成形拉伸 而形成’但例如使拉伸時之拉伸平衡比（DRB)較大，使中 心導體Π)與絕緣體u之間之間隙G較少，可提高密著力。 反之’若使DRB較小’中心導體1〇與絕緣體i i之間之間 隙G較變多，密著力低下。 另外’ DRB係在設擠製機之壓模徑為〇ι、螺紋接管外 徑外徑為D2、絕緣體徑為dl、中心導體徑為⑴夺，以刪= (D1/D2) / (d2/dl)表示。在本發明中係以此DRB成為 1.2以上之方式進行絕緣體丨丨之拉伸。 此外，本發明中係於同軸纜線之中心導體10使用將 AWG43以上之細徑之導體素線撚合之導體，於絕緣體丄工 使用具有難燃性且介電常數較小之氟樹脂者。 此外，進行差動信號傳送之成對之同軸纜線之間（於 圖中係2a與2b、3a與3b、4a與4b、5a與5b)係鄰接配 置。另外，雖可將成對之同軸纜線撚合，但單純平行靠近 之做法不會對絕緣體1丨給予變形，故對於延遲時間差增加 之抑制為有利。 圖2係說明上述之中心導體10與絕緣體11之密著力 (拉拔力/導體剖面積）中之拉拔力之測定方法之圖，如以 201239901 下測定。 (1) 將同軸纜線1之護套9與遮蔽導體8，將絕緣體i i 剝出 5 〇 ΠΊ πι。 (2) 將露出之絕緣體1 1之中除去40mm而將中心導體 1〇剝出40mm。在離中心導體1〇之前端5〇mm之位置將中 心導體10與絕緣體n從同軸纜線丨切離。絕緣體u係成 為剝出10 m m。 (3) 準備比中心導體10之徑大且比絕緣體丨丨之徑小之 徑之孔之壓膜14。於此壓膜14通過中心導體1〇。 其次，將中心導體10以夾持構件丨5把持，將壓膜】4 以夾持構件16把持，壓膜14係固定為不會移動，以中心 導體ίο從絕緣體u拉拔之方式將中心導體10以1〇〇mm/ 分之速度拉。此時，測定將中心導體1〇拉拔之力（N)， 以將其平均值以中心導體1〇之剖面積除之值為密著力。 中心導體ίο與絕緣體n之密著力大即係如於圖2(b) 黑頁示，絕緣體11之内徑從圓形狀往中心導體1〇之間隙G 落入。中心導體10與絕緣體n之間之間隙G變小，故靜 電容量雖會多少變大，但在纜線長度方向之變動量變少。 於圖3顯不根據本發明之多心信號纜線之評價結果。 做為本發明，中心'導體使用將與AWG3M目當之外徑〇 〇5職 之素線7條撚合而外徑〇15mm <導體（導體剖面積 〇.〇137_2)。對此將絕緣體η α壓模徑7_與螺紋接管 外徑2顏之十字頭成形為成為外徑〇41随，對此施加外部 導體12與外部覆蓋層13而使成為同軸繞線。此同軸缆線 201239901 之DRB係1.28，其拉拔力係丨646*1〇·3 ( N)，密著力（拉 拔力/導體剖面積）為〗2〇*1〇_3 ( Ν/ιηίη2)。 此外’做為本發明，中心導體使用將與AWG40相當之 卜位0.03mm之素線7條樵合而外徑之導體（導體 剖面積〇.〇〇49_2)。對此將絕緣體11以壓模徑6.5mm與 螺紋接管外徑2mm之十字頭成形為成為外徑G 24_，對此 施加外4導體12與外部覆蓋層13而使成為同軸纜線。此 同軸纜線之DRB係1.22,其拉拔力係〇.676*1〇·3(Ν)，密 著力（拉拔力/導體剖面積）為136*1〇.3 ( N/mm2)。 ，做^本發明之比較例品，中心導體使用將與錄⑽相 田之外仏0·05_之素線7條撚合而外徑〇」5馳之導體（導 體剖面積0.CH3.W)。對此將絕緣體"以壓模徑7_與 螺紋接管外徑2.5mm之十字頭成形為成為外徑（) 4mm，對 此施加外部導體12與外部覆蓋層13而使成為同軸纜線。 此同㈣線之麵係⑽，其拉拔力係丨柳^⑴， 密著力（拉拔力/導體剖面積）為1〇3M〇-3 (N/mm2)。 此外，做為本發明之比較例品，中心導體使用將與 AWG40相當之外徑0.03mm之辛 、 心京線7條撚合而外徑〇 〇9mm 之導體（導體剖面積〇.〇〇49mm2)。唞仏收妨 ; 對此將絕緣體11以壓 模徑6mm與螺紋接管外徑2·5 m之十子頭成形為成為外徑 0_23mm，對此施加外部導體12 興外。卩覆羞層13而使成A 同軸纜線。此同轴纜線之Drr 马 係0.94，其加姑夬及 9 201239901 此外，做為本發明之比較例品，中心導體使用將與 AWG42相當之外徑0.025mm之素線7條撚合而外經 〇.〇75mm之導體（導體剖面積0.0034mm2)。對此將絕緣體 11以壓模徑6mm與螺紋接管外徑2.5 mm之十字頭成形為成 為外徑0.175mm’對此施加外部導體12與外部覆蓋層13 而使成為同軸纜線。此同軸纜線之DRB係1.03，其拉拔力 係0.04*10·3( N)，密著力（拉拔力/導體剖面積）為n4*1〇-3 (N/mm2 )。 將上述之同軸缆線之2條平行密接，測定其延遲時間 差之結果’於本發明中，任意一者皆降低為4〇 ( ps/in )。 另一方面’於比較例品中亦同樣測定延遲時間差之結果， 任意一者皆為超過40 ( ps/m) 80 ( ps/m)以下 由以上之結果，只要由撚線構成之中心導體丨〇與絕緣 體U之社、著力為12〇*i〇·3 ( N/mm2),將可滿足使延遲時 間差為40 (ps/m)以下之要求。此外，在此場合於中心 導體1 〇上將絕緣體1 1拉伸成形為DRG為1.2以上較理想。 【圖式簡單說明】 圖1係說明本發明之做為對象多心信號纜線之一例之 圖2係說明本發明中之同軸纜線之拉拔力之測定方法 之圖。 圖3係顯示根據本發明之多心信號纜線之評價結果之 10 201239901 【主要元件符號說明】 1 多 心 信 號 纜 線 2a〜5b 同 轴 纜 線 6 電 源 用 之 纜 線 7 控 制 用 之 纜 線 8 遮 蔽 導 體 9 護 套 10 中 心 導 體 11 絕 緣 體 12 外部 導 體 13 外部 覆 蓋 層201239901 VI. Description of the Invention: [Technical Field] The present invention relates to a multi-core cable for signal transmission such as a high-speed digital signal and a method of manufacturing the same. [Prior Art] Because of the advancement of information communication technology, the frequency band of communication cables has been extended to the GHz band. In addition, differential signal transmission using two cables such as a DVI cable suitable for interface specifications for connecting a computer to a display has become mainstream. This differential signal transmission is performed by transmitting a signal having a phase difference of 180 degrees into two cables at the same time and transmitting them on the receiving side to improve the output and has a noise removing function. However, there is a problem that the k-number is deteriorated due to the delay time difference transmitted by the signal of the two cables. For this reason, for example, Patent Document 1 discloses that the two coaxial cables having the same cross-sectional shape and the same length are used in pairs, and that the individual coaxial cables are cut out from the same cable to reduce the delay time difference. Further, Patent Document 2 discloses that the tensile balance ratio (DRB) of the coated electric wire is about 1.0 degree when the resin is used for the insulator and the insulator is coated with the insulator. CITATION LIST Patent Literature Patent Literature 1: JP-A-2004-1, 19,060, Patent Document 2, International Publication No. 2005/052015, No. 200539901, SUMMARY OF THE INVENTION [Problems to be Solved by the Invention] The delay time difference of the cable is The physical length of the cable and the dielectric constant of the body of the cable are determined. If the materials of the two pairs are the same, the delay time difference will be reduced. However, in the manufacture of a cable, when the conductor (the center conductor of the coaxial cable) is covered with an insulator, especially when the middle body is composed of an i-line, there is a gap between the center conductor and the insulator. . The & gap is caused by a change in the length of the cable. Therefore, there will be problems with itching + constant in performance. In the present invention, in view of the above-described solid state, the multi-heart signal I line which reduces the variation of the delay time difference in the longitudinal direction of the I line in the gap between the intermediate body and the insulator is provided, and the manufacturing method thereof is purpose. [Means for Solving the Problem] The multi-core I line of the month of the month is a multi-heart signal I line that accommodates a plurality of coaxial I-lines covered by a conductor composed of a broadcast wire, and is characterized in that the coaxial I The adhesion between the center conductor of the wire and the insulator (drawing force / conductor scraping area) is 120*10-3 (N/mm2) or more. Further, the central guiding system is a fine entangled wire corresponding to or larger than the AWG 34, and the insulating system is a fluororesin. Further, it is preferable that the coaxial cables of the plurality of the plurality of coaxial cables are arranged adjacent to each other in the differential transmission. Further, the manufacturing method of the multi-heart signal vertical of the present invention is a method of manufacturing a multi-heart signal cable that accommodates a plurality of coaxial cables in which a center conductor composed of a twisted wire is covered with an insulator, and the insulator 4 in the center conductor is 201239901 Stretching at a tensile balance ratio of 1.2 or more, the adhesion force (drawing force/conductor cross-sectional area) 〇*, L7 μ〇, N/IW of the insulator in the coaxial cable [Effect of the invention] According to the present invention As a result, the gap between the center conductor and the insulator can be reduced, and the delay time difference in the longitudinal direction of the cable can be reduced. (4) The variation of the delay time difference is suppressed to 4 〇ps/m or less. [Embodiment] An embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing an example of a multi-heart signal magic line of the present invention as a subtraction line, a 6-series indicating a power supply line indicating a thin line for control, 8 means a shield conductor, and 9 means a sheath 10 system. The center and the conductor '(4) indicate an insulator, 12 denotes an outer conductor, and 13 denote an outer cover. The so-called multi-heart signal mirror line of the present invention refers to a shield conductor 8 that transmits a high-speed digital signal = a plurality of coaxial cables 2a to 5b, and a core 1 is covered with a sheath 9 Signal horizon. Further, a composite cable such as a power cable 6 or a control cable 7 may be included in addition to the coaxial wires 2a to 5b. The coaxial line 2a to 5b is formed by, for example, a center conductor composed of a twisted wire: an insulator u is covered, and the outer conductor 12 is disposed on the outer periphery of the insulator u, and the outer cover layer 13 is covered on the outer side. The center and the conductor 1 are made of, for example, a tin-copper soft copper wire, and 7 wires of an outer diameter of 0.05 mm are twisted together to make 5 201239901 a center conductor having an outer diameter of 0.15 mm (0.0137 mm 2 and AWG # 36 equivalent), or The strip of 0.03mm diameter is twisted and combined as the center conductor of the outer diameter 〇〇9mm (0.0049mm2 is equivalent to AWG #40). A fluororesin such as FEp or pFA can be used for the insulator 11. The thickness and the outer diameter of the insulator 11 are in the middle to the outer diameter of the conductor 〇. 15mm in the case of obtaining a predetermined characteristic impedance (5 〇 Ω), 〇 13 mm thick, and the outer diameter of the insulator 〇 .4lmm 'in the outer diameter of the center conductor 〇 In the case of 〇9mm, the outer diameter of the 〇75mm thick insulator is 0.24mm. The outer conductor 12 is a bare copper wire (soft copper wire or copper alloy wire) or a silver-plated or tin-plated soft copper wire or a copper alloy wire which is the same thickness as the prime wire conductor used for the center conductor 1 之外 in the outer periphery of the insulator n. It is formed in a horizontal roll or group configuration configuration. Further, in order to make the shielding function upward, it is also possible to provide a metal foil tape. The outer cover layer 13 is formed by extrusion molding a resin material such as a fluororesin or winding a resin such as a PE tape. The common shielding conductor 8 can be used for a conductor film which is used for a resin film to evaporate aluminum or copper. The conductor strip has a repeating portion of the conductor foil strip wound in a spiral shape of 1 / 8 to 2 / 3 of the bandwidth. It is about 3mm~60mm. The 5 inch sleeve 9 series is formed by extrusion molding, and resins such as PE, EVA, and PU can be used. The present invention relates to the adhesion force (pull force/conductor cross-sectional area) between the center conductor 10 and the insulator 1 formed by the turns of the coaxial fibers 2a to 5b for signal transmission in the above-described multi-heart signal cable. It is characterized by 120*10·3 (N/mm2) or more. The adhesion is large, that is, the contact between the center conductor 10 and the insulator 11 is filled. That is, the gap G between the center conductor 10 and the insulator 11 is less than that of 6 201239901 - r fis. i u . If there is less gap G between the center and a * A i, the dielectric constant of the cable green in the length direction is quite gentle and tender, and the double motion is also less. As a result, the number of coaxial cables of a plurality of bars can be made small. It is also recognized that λ ^ and j are further 'relative to the center conductor area (mm2), which can be expressed by the force (N) required to pull the center conductor 10 from the insulator. The insulator 11 is formed by stretching and forming a shape other than the center conductor 10, but for example, the tensile balance ratio (DRB) during stretching is large, and the gap between the center conductor Π) and the insulator u is G. Less, can increase the adhesion. On the other hand, if the DRB is made smaller, the gap G between the center conductor 1 〇 and the insulator i i is increased, and the adhesion is lowered. In addition, the DRB system has a die diameter of 〇ι, the OD outer diameter is D2, the insulator diameter is dl, and the center conductor diameter is (1), to delete = (D1/D2) / (d2/ Dl) indicates. In the present invention, the stretching of the insulator is carried out in such a manner that the DRB becomes 1.2 or more. Further, in the present invention, a conductor in which a conductor wire having a small diameter of AWG 43 or more is twisted is used for the center conductor 10 of the coaxial cable, and a fluororesin having a flame retardancy and a small dielectric constant is used in the insulator. Further, a pair of coaxial cables for performing differential signal transmission (in the drawings, 2a and 2b, 3a and 3b, 4a and 4b, 5a and 5b) are arranged adjacent to each other. Further, although the pair of coaxial cables can be twisted together, the parallelism of the insulators is not deformed, so that it is advantageous to suppress the increase in the delay time difference. Fig. 2 is a view for explaining a method of measuring the drawing force in the adhesion force (drawing force/conductor sectional area) of the center conductor 10 and the insulator 11 described above, as measured under 201239901. (1) The sheath 9 of the coaxial cable 1 and the shield conductor 8 are stripped of the insulator i i by 5 〇 π πι. (2) Remove 40 mm from the exposed insulator 1 1 and peel the center conductor 1 to 40 mm. The center conductor 10 and the insulator n are cut away from the coaxial cable at a position 5 ft from the front end of the center conductor 1 。. The insulator u is stripped to 10 m m. (3) A pressure film 14 having a larger diameter than the diameter of the center conductor 10 and having a smaller diameter than the diameter of the insulator 准备 is prepared. The laminate 14 is passed through the center conductor 1〇. Next, the center conductor 10 is held by the holding member 丨5, the pressing film 4 is held by the holding member 16, and the pressing film 14 is fixed so as not to move, and the center conductor is pulled from the insulator u by the center conductor ίο. 10 Pull at a speed of 1〇〇mm/min. At this time, the force (N) at which the center conductor 1 is pulled is measured, and the average value is divided by the sectional area of the center conductor 1 值为 as the adhesion. The adhesion between the center conductor ί and the insulator n is as shown in the black page of Fig. 2(b), and the inner diameter of the insulator 11 falls from the circular shape to the gap G of the center conductor 1〇. Since the gap G between the center conductor 10 and the insulator n is small, the electrostatic capacity is somewhat increased, but the amount of variation in the cable length direction is small. The evaluation results of the multi-heart signal cable according to the present invention are shown in FIG. As the invention, the center 'conductor use will be combined with the AWG 3M outer diameter 〇 〇 5 position of the prime line and the outer diameter 〇 15mm < conductor (conductor sectional area 〇. 〇 137_2). In this case, the insulator η α die diameter 7_ and the nipple outer diameter 2 face crosshead are formed so as to become the outer diameter 〇41, and the outer conductor 12 and the outer cover layer 13 are applied thereto to form a coaxial winding. This coaxial cable 201239901 has a DRB system of 1.28, its drawing force is 丨646*1〇·3 (N), and the adhesion force (drawing force/conductor sectional area) is 〖2〇*1〇_3 ( Ν/ιηίη2 ). Further, as the present invention, the center conductor is a conductor of the outer diameter (conductor sectional area 〇.〇〇49_2) which is twisted by a strip of 0.03 mm which is equivalent to the AWG 40. On the other hand, the insulator 11 is formed into a cross-shaped head having a die diameter of 6.5 mm and a nip pipe outer diameter of 2 mm so as to have an outer diameter G 24_, and the outer four conductors 12 and the outer cover layer 13 are applied to form a coaxial cable. The DRB of this coaxial cable is 1.22, and its pull-out force is 676.676*1〇·3(Ν), and the adhesion force (drawing force/conductor sectional area) is 136*1〇.3 (N/mm2). According to the comparative example of the present invention, the center conductor is a conductor which is combined with 7 wires of the 仏0·05_ line outside the phase (10) and has an outer diameter of 55 (the conductor sectional area is 0.CH3.W ). In this case, the insulator was formed into a crosshead of the die diameter 7_ and the outer diameter of the nipper of 2.5 mm so as to have an outer diameter of 4 mm, and the outer conductor 12 and the outer cover 13 were applied thereto to form a coaxial cable. The surface of the same (four) line (10), the drawing force is 丨柳^(1), and the adhesion force (drawing force/conductor sectional area) is 1〇3M〇-3 (N/mm2). Further, as a comparative example of the present invention, a conductor having a diameter of 0.03 mm corresponding to the AWG 40 and a strip of symmetry and a diameter of mm9 mm (the conductor sectional area 〇.〇〇49 mm2) is used for the center conductor. ). In this case, the insulator 11 is formed with a die diameter of 6 mm and a nipper outer diameter of 2·5 m to form an outer diameter of 0 to 23 mm, and the outer conductor 12 is applied thereto.卩 卩 层 layer 13 to make an A coaxial cable. This coaxial cable has a Drr horse system of 0.94, which is a combination of acupuncture and 9 201239901. In addition, as a comparative example of the present invention, the center conductor is combined with a strip of the outer diameter of 0.025 mm which is equivalent to the AWG 42. 〇.〇75mm conductor (conductor sectional area 0.0034mm2). For this purpose, the insulator 11 is formed into a crosshead having a die diameter of 6 mm and a ferrule outer diameter of 2.5 mm so as to have an outer diameter of 0.175 mm', and the outer conductor 12 and the outer cover 13 are applied to form a coaxial cable. This coaxial cable has a DRB of 1.03, a drawing force of 0.04*10·3 (N), and a sealing force (drawing force/conductor sectional area) of n4*1〇-3 (N/mm2). The two coaxial cables are closely connected in parallel to measure the result of the delay time difference. In the present invention, either one is reduced to 4 〇 (ps/in). On the other hand, the result of the delay time difference is also measured in the comparative example, and any one of them is more than 40 (ps/m) 80 (ps/m) or less. The above result is as long as the center conductor composed of the 捻 line. 〇 and the insulator U, with a force of 12〇*i〇·3 (N/mm2), will satisfy the requirement that the delay time difference is 40 (ps/m) or less. Further, in this case, it is preferable to stretch the insulator 11 from the center conductor 1 为 to have a DRG of 1.2 or more. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing an example of a multi-heart signal cable of the present invention. Fig. 2 is a view for explaining a method of measuring a drawing force of a coaxial cable in the present invention. Fig. 3 is a view showing the evaluation result of the multi-heart signal cable according to the present invention. 10 201239901 [Description of main component symbols] 1 Multi-heart signal cable 2a to 5b Coaxial cable 6 Cable for power supply 7 Control cable 8 Shielding conductor 9 Sheath 10 Center conductor 11 Insulator 12 Outer conductor 13 External cover