200923981 九、發明說明： 【發明所屬之技術領域】 本發明係有關於一種高頻之阻抗特性優異之線圈組 件，特別是有關於用作變壓器或共模濾波器等之線圈組件。 【先前技術】 個人電腦或行動終端機等電子機器之信號傳送速度之 高速化或驅動頻率之高頻化正發展中。例如，傳送速度 400Mbps 之 IEEE1394a 或傳送速度 480Mbps 之 USB2.0 規格 已廣泛普及，亦面臨更高速之HDMI( 700Mbps)、IEEE1394b (8 00Mbps )。在該等高速差動傳送使用之共模濾波器等線 圈組件要求因應高頻、小型等。例如，於專利文獻1揭示 高頻用共模濾波器。在專利文獻1中，揭示藉於進行捲線 之芯1兩端之緣部間設置相對磁導率低於芯1之磁遮蔽 部，而可在高頻提高阻抗。 〔專利文獻1〕 日本專利公開公報2003 - 1 686 1 1號 【發明內容】 根據專利文獻1，可獲得在高頻率爲高阻抗之共模濾 波器。然而，上述專利文獻1所揭示之習知線圈組件一旦 增闻筒頻之阻抗，則頻帶變窄，因此非較佳之結構。因而， 期望不管此結構爲何，均提高阻抗之線圈組件。 因此，本發明之目的在於提供一種在高頻帶發揮優異 特性之線圈組件。 本發明線圈組件之特徵在於，包含六方晶鐵氧體鐵 芯、捲繞於該六方晶鐵氧體鐵芯之一對導體以及形成於前 200923981 述六方晶鐵氧體鐵芯表面，連接前述導體之端子電極；前 述六方晶鐵氧體鐵芯具有捲繞前述一對導體之繞組部，前 述繞組部之前述導體之捲繞軸向之起始磁導率大於與前述 捲繞軸向垂直之至少一方向之起始磁導率。由於六方晶鐵 氧體鐵芯具有使與C軸垂直之方向作爲易磁化面之磁異向 性，因此定向而提高起始磁導率，可獲得高阻抗。若將令 起始磁導率大之方向作爲導體之捲繞軸向之此種結構應用 於共模濾波器，即可改善高頻帶之共模雜訊衰減量。 又，較佳係在前述線圈組件中，前述繞組部在與前述 繞組軸垂直之方向具有起始磁導率是與前述捲繞軸向之起 始磁導率約略相等之其他方向。根據此結構，可有效地改 善高頻帶之雜訊衰減量。 又，在前述線圈組件中，前述六方晶鐵氧體鐵芯較佳 係具有貫穿孔，以前述貫穿孔周圍之一部份作爲前述繞組 部，經由前述貫穿孔’將前述導體捲繞，前述端子電極形 成於至少與前述六方晶鐵氧體鐵芯之前述貫穿孔之貫穿方 向平行之面。根據此結構’可更抑制磁通之漏磁，而進一 步改善雜訊衰減量。 其特徵又在於，在前述線圈組件中，前述其他方向較 佳係和前述貫穿孔之貫穿方向及前述捲繞軸向垂直之方 向。根據此結構，由於在圍繞貫穿孔之方向之起始磁導率 增高，因此可有效改善高頻帶之雜訊衰減量。 又，在具有貫穿孔之前述線前組件中，前述其他方向 亦可爲前述貫穿孔之貫穿方向。特別是，尤佳者係當此結 200923981 構考慮將圍繞貫穿孔之磁路方向置換成前述捲繞軸向 可符合六方體鐵氧體鐵芯全體爲更佳。此乃因爲，在 況下，磁路方向全體亦沿著起始磁導率高之方向因此 本發明另一線圈組件之特徵在於，包含六方晶鐵 鐵芯、捲繞於該六方晶鐵氧體鐵芯之一對導體以及形 前述六方晶鐵氧體鐵芯表面，連接前述導體之端子電 前述六方晶鐵氧體鐵芯具有捲繞前述一對導體之繞組 前述繞組部之至少一部份爲，結晶方位之C軸定向於 述導體之捲繞軸向約略垂直之面內方向。根據此結構 繞軸向之起始磁導率增高，可有效改善高頻帶之雜訊 量。 .> 又，在前述線圈組件中，前述繞組部較佳爲，結 向之C軸定向於與前述導體之捲繞軸向約略垂直之面 向的一個方向。根據此結構，可有效地改善高頻帶之 哀減量。 又，在前述線圈組件中，前述繞組部較佳係具有 方向之C軸定向於法線方向之表面。根據此結構，亦 效地改善局頻帶之雜訊较減量。 又，在前述線圈組件中，前述六方晶鐵氧體鐵芯 係具有貫穿孔，以前述貫穿孔周圍之一部份作爲前述 部，經由前述貫穿孔’將前述導體捲繞，前述端子電 成於至少與前述六方晶鐵氧體鐵芯之前述貫穿孔之貫 向平行之面，前述繞組部爲，結晶方位之C軸是定向 述貫穿孔之貫穿方向。根據此結構，由於圍繞貫穿孔 時， 此情 〇 氧體 成於 極； 部， 與前 ，捲 衰減 晶方 內方 雜訊 結晶 可有 較佳 繞組 極形 穿方 於前 之方 200923981 向之起始磁導率增高，因此’可有效地改善高頻帶之雜訊 哀減量。 又’在前述線圈組件中’前述六方晶鐵氧體鐵芯較佳 係具有貝芽孔’以即述貫穿孔周圍之一部份作爲前述繞組 部，經由目II述貫穿孔’將即述導體捲繞，前述端子電極形 成於至少與則述六方晶鐵氧體鐵芯之前述貫穿孔之言穿方 向平行之面，前述六方晶鐵氧體鐵芯之前述貫穿孔側之內 側面及與該內側面相對之外側面之結晶方位之C軸係分別 定向於前述內側面或前述外側面之法線方向。根據此結 構，由於圍繞貫穿孔之方向之起始磁導率增高，因此，可 有效地改善高頻帶之雜訊衰減量。 再者，在具有貫穿孔之BU述線圈組件中，前述六方晶 鐵氧體鐵芯爲，相對於前述貫穿方向垂直之方向的截面形 狀較佳爲在前述貫穿方向實質上不變化之形狀。此結構由 於可以簡易之方法製作六方晶鐵氧體鐵芯，因此，量產性 優異。而且，截面形狀在前述貫穿方向實質上無變化之形 狀係指可容許六方晶鐵氧體鐵芯之角部份之內圓角等的差 異之旨趣。 又，在前述線圈組件中，前述六方晶鐵氧體鐵芯較佳 係長方體形狀。使用長方體形狀之六方晶鐵氧體鐵芯對線 圈組件之低背化、小型化有利。 又，在前述線圈組件中，前述貫穿孔之孔形狀較佳係 矩形，而且該矩形之各角部爲圓弧狀，前述角部之圓弧半 徑爲貫穿孔截面形狀之矩形短邊方向長度的1 0 %以上。根 200923981 據此結構，可更改善雜訊衰減量。 又，在前述線圈組件中，前述貫穿孔之孔形較佳係矩 形’而且前述貫穿孔之與前述繞組軸垂直之方向的寬度爲 前述一對導體之平均繞線線距以上。此結構有助於雜訊衰 減量及信號損失之改善。 而且，上述各結構亦可適當組合。 根據本發明，可提供在高頻帶中，發揮優異特性之線 圈組件。 (> % 【實施方式】 以下，具體說明本發明線圈組件之實施形態，本發明 未必限於該實施形態。在各實施形態中，相同構件標以相 同標號。第1圖係顯示本發明線圈組件一實施形態之繞組 型共模濾波器之構造的圖式。第1 ( a )圖係立體圖，第1 (b )圖係顯示緣部裡側之底面圖之一部份。本發明之線圈 組件具備六方晶鐵氧體鐵芯、捲繞於該六方晶鐵氧體鐵芯 ^ 之一對導體以及形成於前述六方晶鐵氧體鐵芯表面，連結 前述導體之端子電極，可作爲表面封裝型線圈組件來使 用。可使用I型芯或滾筒型芯，形成開磁路，亦可形成閉 磁路。於第1圖顯示漏磁通少之閉磁路構造之共模濾波 器。線圈組件不限於共模濾波器，亦可適用於其他濾波器、 變壓器。又’亦可爲導線不限一對，再增加導線數之結構。 而且’以下說明之結構不僅爲使用一對導線之情形，亦可 適用於使用諸如電感器或晶片磁珠之一條導線之線圈組 件。 200923981 於構成六方晶鐵氧體鐵芯之第一鐵氧體1之繞組部3 捲繞作爲一對導線之導線6、7。可使用以薄樹脂膜等絕緣 包覆銅等電阻率小之材質之線材於導體。而且，導體亦可 使用以薄膜製程或印刷製程形成之導體圖案。此一對導體 於例如作爲共模'應波益時，爲特別減低商頻之差動信號之 損失’較佳係約略平行地保持一定之線間隔來捲繞。於長 方體形繞組部3之一端配置於與繞組軸垂直之方向且爲彼 此相反方向突出之長方體形緣部4。於繞組部3之另一端 同樣配置緣部5。與繞組部3及緣部4、5之捲繞軸垂直之 方向（與緣突出之方向垂直之方向）爲相同寬度，第一鐵 氧體形成截面略呈Η型之柱狀體。而且，繞組部之形狀不 限於長方體狀’亦可爲圓柱狀等。又，與繞組部3及緣部 4、5之捲繞軸垂直之方向（圖中之y方向）雖未必須爲相 同寬度，卻可藉由呈相同寬度之形狀，更提高生產性。於 繞組部兩端之該緣部4、5之上面接著固定平板狀第二鐵氧 體2，與繞組部3相對配置。接著材料爲樹脂等，爲提高 磁電路之效率，接著層較佳爲很薄。於緣部4、5之下面形 成端子電極8〜1 1作爲外部電極。端子電極可藉由塗布銀 膏後燒結形成，亦可藉由塗布散布有銀粉之膏於熱硬化樹 脂後，熱硬化而形成。導線6之一端連接於端子電極8， 另一端連接於端子電極1 0。導線7之一端連接於端子電極 9，另一端連接於電極11。而且，端子電極不僅形成於作爲 封裝面之下面側，亦可如第1圖所示，形成於與該面垂直 之整個側面。 -10- 200923981 第一鐵氧體1及第二鐵氧體2使用磁導率、結晶粒之 結晶方向具有異向性之六方晶鐵氧體。。此六方晶鐵氧體 具有易磁化面。使用Z型鐵氧體、Y型鐵氧體、W型鐵氧 體等軟鐵氧體。當中，由於Z型鐵氧體在1GHz左右之高 頻帶之磁導率高，因此較佳合。以與c軸垂直之方向作爲 易磁化面之六方晶鐵氧體可以藉由定向，提高磁導率。於 此情況下’與易磁化面平行之方向之磁導率增高。在第1 圖之實施形態中，使用如此定向之六方晶鐵氧體，第一鐵 氧體之繞組部3之導線之捲繞軸向的X方向起始磁導率μ x 大於與捲繞軸向垂直之方向之磁導率// y、# Z。於構成線 圈組件情況下，由於用在該線圈組件之六》方晶鐵氧體鐵芯 爲確保繞組區域，易呈於前述捲繞軸向長之形狀，因此， 該方向之磁路變長。因而，藉由提高此方向之磁導率，可 獲得高至高頻率爲止之雜訊衰減特性。又，第二鐵氧體可 使提高磁導率之方向爲屬於捲繞軸向之X方向，亦可爲與 繞組軸垂直之緣部之突出方向。又，鐵氧體2亦可爲與鐵 氧體1不同之磁性材料。藉由使用高磁導率之NiZn鐵氧體 或MnZn鐵氧體’可增加低頻率之阻抗，獲得在低頻率高 之雜訊衰減特性。 具有上述X方向的起始磁導率//X大於與捲繞軸向垂 直之方向之磁導率# y、// ζ之定向狀態的六方晶鐵氧體以 在一方向磁場中將六方晶鐵氧體粉末成形而得之成形體燒 成而得之六方晶鐡氧體燒結體實現。第1 2 ( a )圖係顯示其 定向狀態之模式圖。於此情況下，由於平板狀六方晶鐵氧 -11- 200923981 體之結晶粒1 2 1定向成與圖中之板面一致之易磁化面（c 面）與一方向、亦即磁場施加方向（X方向）平行，因此 可提高該方向之磁導率。另一方面，由於易磁化面隨機地 朝向與該方向垂直之面方向（yz方向），因此發現c面內 方向之高磁導率〇與C軸方向之低磁導率之中間磁導率均 等’而可抑制該面方向之磁導率之極端降低。若使用磁導 率局之_場施加方向作爲捲繞軸向，繞組部3之結晶方位 之c軸即定向於與前述導體之捲繞軸向約略垂直之面內方 向。亦即，利用提高磁導率之方向之上述結構之效果在捲 繞有一對導體之六方晶鐵氧體鐵芯之繞組部之結晶方向的 c軸定向於與前述導體之捲繞軸向約略垂直之面內方向之 狀態下實現。 提高繞組部之捲繞軸向之磁導率之結構較佳係與構成 六方晶鐵氧體鐵芯之第一鐵氧體之繞組部3之與導體之捲 繞軸向垂直之一方向的起始磁導率小於前述捲繞軸向之起 始磁導率，與前述捲繞軸向垂直之另一方向之起始磁導率 和前述捲繞軸向之起始磁導率約略相等者。在與捲繞軸向 垂直之方向具有起始磁導率和捲繞軸向之起始磁導率約略 相等之其他方向之此結構呈於使用旋轉磁場作爲六方晶鐵 氧體粉末成形時之施加磁場等，使六方晶鐵氧體之結晶粒 面定向時實現之狀態。第1 2 ( b )圖係顯示該定向狀態之模 式圖。由於可定向成使易磁化面與垂直於旋轉磁場之軸（y 方向）之面方向對齊，因此，該面內方向（zx方向）之磁 導率增高。於此情況下，c軸定向於旋轉磁場之軸向（y方 -12- 200923981 向）。另一方面，該面內以外之方向（例如y方向）之磁 導率降低。若旋轉磁場之施加面配置成與導體之捲繞軸向 平行，即成爲構成六方晶鐵氧體鐵芯之第一鐵氧體之繞組 部3之前述捲繞軸向（X方向）的起始磁導率至少大於與 前述捲繞軸向垂直之一方向（例如y方向）之起始磁導率， 與導體之捲繞軸向垂直之其他方向（例如z方向）之起始 磁導率和前述捲繞軸向之起始磁導率約略相等。於此情況 下’包含捲繞軸向與前述其他方向之面對應於前述旋轉磁 場施加面。 再者，若前述其他方向爲與第一鐵氧體1與第二鐵氧 體2之相對方向（z方向）、亦即緣部連結第一鐵氧體與第 二鐵氧體之方向，即因第一鐵氧體內之磁路方向可完全利 用磁導率高之方向，因此，可抑制磁通之漏磁，而特別適 合。藉由使用面定向之六方晶鐵氧體鐵氧，使繞組部之c 軸朝向特定之一個方向。若使用上述其他方向爲第一鐵氧 體及第二鐵氧體之相對方向（z方向），繞組部3之結晶方 位之c軸即定向於約略垂直於前述捲繞軸向，且與第一鐵 氧體及第二鐵氧體之相對方向（z方向）約略垂直之一個 方向。即’利用提高面定向之磁導率之上述結構之效果可 在繞組部3之結晶方位之c軸定向於約略垂直於前述捲繞 軸向，且與第一及第二之相對方向（z方向）約略垂直之 一個方向之狀態下實現。 參照第2圖’就本發明線圈組件之第二實施形態作說 明。第2圖係顯示本發明線圈組件之第二實施形態之構造 -1 3 - 200923981 之圖式。第2(a)圖係立體圖，第2(b)圖係顯示緣部之 裡側之底面部之一部份。具有與第一實施形態相同之功能 之部份附上相同標號。第二實施形態係六方晶鐵氧體鐵芯 21 —體構成’具有貫穿孔24。以貫穿孔24周圍之一部份 作爲繞組部，經由貫穿孔24，繞組導體6、7。端子電極形 成於與六方晶鐵氧體鐵芯21之貫穿孔24之貫穿方向平行 之下面。由於捲線及端子電極與第一實施形態相同，因此， 省略詳細說明。貫穿孔2 4以四個垂直相交之平面構成，其 截面爲矩形。使用四個平面中之一個，捲繞一對導線。由 於導線之捲繞使用一個平面即可，因此貫穿孔24之截面未 必須爲矩形，只要內側面之至少一部份爲平面即可。繞組 部23約略呈以貫穿孔24之平面中之一個爲一面之長方體 形狀。六方晶鐵氧體鐵芯2 1於繞組部2 3之兩端具有一對 腳部22、25，其等以前述繞組部爲基準，突出於貫穿孔24 之對側。由於僅以六方晶鐵氧體鐵芯2 1構成閉磁路，在磁 路途中無接著材料等非磁性之間隙，因此磁電路之效率 高，而可獲得高雜訊衰減特性。 由於一體構成六方晶鐵氧體鐵芯以外之部份與第一實 施形態相同，因此’省略說明’使用於繞組部定向之六方 晶鐵氧體之結構及其效果與第一實施形態相同。且由於在 第二實施形態情況下’六方晶鐵氧體鐵芯以一體構成，因 此，繞組部2 3之磁導率、定向狀態仍然連續地爲六方晶鐵 氧體鐵芯2 1全體之配向狀態。例如，若使用上述面定向之 六方晶鐵氧體鐵芯’而呈繞組部2 3之結晶方向之c軸定向 -14- 200923981 於貫穿孔之貫穿方向之狀態，亦即呈起始磁導率與繞組軸 約略相等之其他方向爲貫穿孔之貫穿方向以及和捲繞軸向 垂直之方向之狀態，即因磁路之周圍方向與起始磁導率高 之面內方向一致，且於磁路亦無間隙，以致對雜訊衰減量 之提高特別有效。 在第二實施形態中，六方晶鐵氧體鐵芯21之相對於貫 穿孔24之貫穿方向垂直之方向的截面形狀呈在前述貫穿 方向實質上無變化之形狀。若截面形狀採用一定形狀，即 因可以於一方向加壓之加壓成形或按壓成形等簡易形成， 因此，生產性進一步提高。雖然此點在第一實施形態中亦 相同，然而由於第二實施形態之結構零件件數少，因此特 別適合。而且，在第二實施形態中，雖然一對腳部22、25 爲以圖之y方向爲長向之長方形，端子電極8及9、10及 1 1之群組形成同一平面狀’然而，卻可以切塊機等於端子 電極8及9間、端子電極10及1 1間形成溝，使形成端子 電極之面獨立。 雖然上述定向可藉由於成形時施加磁場進行，惟在採 用第二實施形態之結構情況下’可使用按壓成形，進行定 向。亦即’線圈組件之製造方法可採用將具有易磁化面之 六方晶鐵氧體粉末按壓成形成具有貫穿孔之第二實施形態 之形狀，而獲得成形體’燒結該成形體，獲得燒結體，使 導線穿過該貫穿孔而捲繞’獲得線圈組件之方法。當於第 二實施形態之六方晶鐵氧體鐵芯21之貫穿孔24之軸向（y 方向）按壓時’藉按壓時之機械定向，六方晶鐡氧體鐵芯 200923981 2 1中，貫穿孔24之內側面側及與其相對之外側面之結 位之c軸分別定向於前述內側面或前述外側面之法 向。於第12(c)圖之模式圖中顯示該定向狀態。第1: 圖之下側部份顯示繞組部之定向狀態。於此情況下， 組部23觀看’顯示與繞組部23之捲繞軸向（X方向） $口 te導率約略相寺之起始紐導率之方向爲貫穿孔之貫 向（y方向）。在使用以旋轉磁場面定向之六方晶鐵 鐵芯情況下，顯示繞組部全體相同之定向狀態，然而 f ' 前述按壓成形之機械定向情況下，繞組部之表面、亦 組部之一部份卻定向。此傾向不限於繞組部，亦於貫 周圍之面及與此相對之外周面全體出現，由於該等定 磁導率隨之提高之方向與線圈組件之磁路方向一致 此，適合作爲本發明線圈組件之芯。特別是與六方晶 體鐵芯一體形成相輔相成，而有助於作爲線圈組件之 及生產性提高。 , 又，亦可藉由於此按壓成形組合磁場定向，亦可 " 六方晶鐵氧體鐵芯之表面及內部之定向模式。例如， 方晶鐵氧體鐵芯之表面呈前述定向狀態，內部呈上述 向定向或面定向狀態，亦可抑制磁通漏磁。而且，亦 第1圖所示之實施形態之第一及/或第二鐵氧體賦與上 壓成形之定向狀態。在使用藉由按壓成形而得之鐵氧 況下，繞組部具有結晶方位之c軸定向於法線方向 面。由於在此情況下，就第一鐵氧體及第二鐵氧體之 面而言，c面與該面平行地定向，因此，爲減低磁阴 晶方 線方 1(c) 在繞 之起 穿方 氧體 ，在 即繞 穿孔 向及》 ，因 鐵氧 特性 改變 令六 一方 可對 述按 體情 之表 貼合 .力， -16- 200923981 較佳係硏磨表面。爲避免此表面硏磨等，尤佳者爲按壓成 形之定向狀態以應用於如第2圖所示例子之具有貫穿孔之 一體型六方晶鐵氧體鐵芯。 又’亦可使用第6圖所示實施形態（第三實施形態） 作爲六方晶鐵氧體鐵芯以一體（亦即以一個構件）構成， 具有貫穿孔之實施形態。第6圖所示實施形態之六方晶鐵 氧體鐵芯3 1與第2圖所示實施形態之不同之點係無相當於 腳部之突起部，從貫穿孔35之貫穿方向觀看之外形爲矩 形，全體之外形呈長方體。在第6圖之實施形態情況下’ 繞組部3 2形成於與隔著矩形貫穿孔3 5，形成有端子電極 36之封裝面側相對之側。捲繞於繞組部32之導體33、34 之兩端環繞六方晶鐵氧體鐵芯3 1之側面（圖中未示）’分 別連接於端子電極36〜39(37圖中未示）。而且’在六方 晶鐵氧體鐵芯31之側面，亦可將端子電極36〜39延伸設 置至與封裝面相對之側之上面，在該上面側，將導線3 3、 3 4連接於端子電極3 6〜3 9。如上述長方體形狀般’無相當 於腳部之突起部之框狀一體型六方晶鐵氧體鐵芯製造穩定 性、量產性優異，而且對線圏組件之低背化、小型化有利。 又，如第6圖所示之實施形態’從貫穿孔之貫穿方向觀看 之六方晶鐵氧體鐵芯之形狀亦包含貫穿孔之形狀’相對於 與封裝面平行之中心線對稱時，由於在製程中無須區別六 方晶鐵氧體鐵芯之方向’因此’可提高量產性。而且’無 相當於腳部之突起部之結構亦可適用於如第1圖之實施形 態般，以複數個鐵氧體構成六方晶鐵氧體鐵芯之情形。 200923981 於第7圖顯示貫穿孔之形態與第2圖所示之實施形態 不同之第四實施形態。在第7 ( a )圖所示之實施形態中， 貫穿孔42之孔形爲矩形，且矩形之各角部爲圓弧狀。第7 (b )圖係該貫穿孔42之放大圖。亦即，貫穿孔之截面形 狀、亦即孔形爲於角設置圓弧之矩形。在以複數個鐵氧體 構成六方晶鐵氧體情況下，可易於其貼合之部份形成間 隙，磁阻增大。針對此，藉由使以一體構成之六方晶鐵氧 體鐵芯4 1之矩形貫穿孔42之各角部呈圓弧狀，可減低磁 阻，而謀求電感之提高。在例如爲共模濾波器情況下，可 提高雜訊衰減量。於此情況下，尤佳者爲在從貫穿孔貫穿 方向觀看之矩形外形中，六方晶鐵氧體鐵芯之各角部呈圓 弧狀。由於圓弧狀之尺寸過小時，無法充份發揮呈圓弧狀 之特性之效果，因此，在令圓弧狀半徑r爲圓弧狀部份之 尺寸情況下，該半徑r較佳在貫穿孔截面形狀之矩形短邊 方向之長度之10%以上。在貫穿孔中，令各角部呈圓弧狀 時，由於該圓弧狀部份高於繞組部之平面，因此，進行捲 繞時，亦可利用作爲使導體離開貫穿孔側面之間隔件。於 此情況下，半徑r較佳係超過導體之半徑。進而，當超過 5 0 %時，貫穿孔便不是矩形，而破壞六方晶鐵氧體鐵芯之 磁路之均一性，因此，半徑r較佳係爲5 0 %以下。又由於 當圓弧狀部份過大時，可均一地捲繞導體之部份縮小，因 此，較佳係沿繞組部之貫穿孔一邊之長度之3〜20 %。而 且，圓弧狀未必須爲完整之圓弧狀，只要在沿貫穿孔截面 之繞組部之一邊，隨圓弧狀部份而消失之直線部份之長度 -18- 200923981 爲前述圓弧狀半徑r即可。而且，前述圓弧狀之角形狀可 在從貫穿方向觀看貫穿孔時之投影形狀中掌握。 如第1圖之結構般，雖然當以不同構件（亦即複數構 件）構成六方晶鐵氧體鐵芯時，無法於孔部份之四個角皆 設置圓弧，卻可藉由使用形成有貫穿孔之一體型六方晶鐵 氧體鐵芯，可於孔部份之四個角皆設置圓弧。特別是在使 用一體型六方晶鐵氧體鐵芯情況下，即使爲去除導體接觸 之部份等之溢料或角而進行圓筒硏磨、珠粒噴擊等硏磨， 矩形貫穿孔之四個角之角部份之圓弧亦不致消失。另一方 面’在使用非一體型六方晶鐵氧體鐡芯情況下，於構成六 方晶鐵氧體鐡芯之各鐵氧體進行硏磨後，將該等貼合，構 成芯時，於芯之孔部份形成反向朝向外側之楔形間隙。因 而，一體型六方晶鐵氧體鐵芯適合施行上述硏磨而製作之 共模濾波器。 又，在貫穿孔之孔形爲矩形情況下，與貫穿孔之捲繞 軸垂直之方向之寬度較佳在一對導體之平均間距以上。平 均間距係採用第7圖所示之繞組之線距p之平均者。而且， 在第7圖顯示之間隔d爲構成一對導體之各導體之中心間 隔。藉由擴大貫穿孔之寬度，可減低信號損失。此係根據 以下之理由者。例如，在使用線圈組件作爲共模濾波器情 況下，差動信號之高頻磁場大部份以對線相互消除，剩餘 之一部份在相鄰之對線之磁場消除，再者，剩下之磁場在 鐵氧體內部產生磁損失，而使信號損失增加。藉由使上部 鐵氧體與捲線之距離大於相鄰對線之距離，在相鄰之對線 200923981 不消除而在剩餘磁場之鐵氧體內部之強度變弱，而減低損 失，藉此，可減低信號損失。由於增大貫穿孔之寬度時’ fe路增長，因此’在需要與GHz頻帶相關之筒頻帶之雜訊 衰減時，若仍然使用磁導率低之習知Ni-Zn系鐡磁體，電 感即降低’無法獲得足以作爲共模濾波器之特性。針對此’ 由於藉由使用定向提高磁導率之六方晶鐵氧體鐵芯，可確 保足夠之電感’因此，可增大貫穿孔之寬度。而且，與上 述貫穿孔之角部份之圓弧形相關之結構或與貫穿孔之寬度 相關之結構不論腳部之有無或六方晶鐵氧體之定向之有 無，均可廣泛地應用於矩形之貫穿孔。 用於本發明中之六方晶鐵氧體鐵芯可使用Z型鐵氧 體、Y型鐵氧體、W型鐵氧體等之燒結體芯。該等六方晶 鐵氧體可依使用之頻率頻域等選擇。依Z型鐵氧體、Y型 鐵氧體之順序，可維持高至高頻爲止之起始磁導率。其中 由於Z型鐵氧體可維持高至1GHz爲止之起始磁導率，且 起始磁導率在上述六方晶鐵氧體中爲最高，因此，適合設 定在1 GH或或超過此之頻帶使用之共模濾波器等之線圈組 件。就Z型鐵氧體而言，以Ba3C〇2Fe24〇4,表示之C〇2Z型者 之起始磁導率之高頻特性優異，而較佳。Z型鐵氧體未必 須爲單相。Z型鐵氧體有包含異相之情形，本發明亦容許 此情形’包含具有異相者在內而稱爲Z型鐵氧體。惟，爲 獲得高起始磁導率，較佳係以Z型鐵氧體爲主相。以Z型 鐵氧體爲主相係指在粉末X射線繞射中，峰値強度最大之 峰値爲Z型鐵氧體者。 -20- 200923981 在此，進一步詳述六方晶鐵氧體之定向。藉由以定向 而提高起始磁導率之方向作爲線圈之捲繞軸向，構成在減 低全體之磁阻，確保高阻抗上爲有利之結構。如上述，Z 型鐵氧體或Y型鐵氧體具有易磁化方向朝向與C軸垂直之 面之磁異向性，而可定向。因而，可使結晶方向之c軸定 向於一面內方向，如上述，於起始磁導率具異向性。又， 由於可藉由定向，使高頻特性不致於降低，大幅提高起始 磁導率，因此，可獲得至高頻爲止高之電感，而可獲得高 至高頻爲止高之雜訊衰減特性。 六方晶鐵氧體之c軸定向於基板之一面內方向之狀態 以X線繞射評估即可。於令繞射峰値之面指數爲（HKL ) 時，在基板之一面進行X線繞射情況下，若相對於c軸平 行之特定面（hkO )之繞射峰値強度Ihk。與垂直於c軸之特 定面（001 )之繞射峰値強度I〇<n之比hko/I。^大於在其他面 進行X射線繞射之情形時，可謂C軸定向於前述一面內方 向。 c軸在一個面內定向之鐡磁體之定向度如以下求出。 在對六方晶鐵氧體基板之一面進行之測量範圍爲2 0 = 2 0 〜80°之X射線繞射圖案中，於令六方晶鐵氧體之所有繞射 峰値之積分強度和爲Σ I ( HKL)(然而，I ( HKL)顯示以 指數（HKL)表示之繞射峰値之積分強度），令L = 0之所 有（ΗΚ0 )繞射峰値之積分強度和爲Σ I ( HK0 )情況下， 求出以f c丄=ς I ( HK0 ) / Σ I ( HKL )賦與之定向度f c丄。在此，I ( Hkl )係於使用令（HKL )面之繞射線之 200923981 峰値角度爲0 (HKL)時，在0 (HKL) —〇.4°至θ + 0.4°之範圍積分之値。若此定向度f c丄大於從其 X射線繞射算出之定向度f c丄，即可謂c軸定向 一面內方向。又，前述定向度f c丄大係表示在前 內方向之c軸之定向顯著。當令此情形之前述一面 爲C軸定向面時，前述C軸定向面中前述定向度f 佳係在0.4以上。當令前述定向度f c丄在0.4以_t 進行X射線繞射之面垂直之方向之磁導率特別高， f ' ' 如在100kHz獲得30以上之磁導率。而且，將具有 度之面稱爲c軸定向面。更佳爲當令定向度f c丄 以上時，可獲得3 5以上之磁導率，而爲較佳之結釋 再者，至少在與前述c軸配向面垂直且相互垂 個面（以下稱爲垂直面）中，從X射線繞射之f (00 18)/1 (110)算出之定向度fc //較佳在0.3 該定向度f c//大係表示c軸朝向與前述垂直面垂 向之結晶粒多。此藉由至少在相互垂直之兩個面中 I . 可保證C軸隨機地轉向。藉由如此進行。在與C軸 平行之方向亦可獲得高磁導率。 又，在評估對象物小情況下，可在掃瞄電子 (SEM)觀察中，進行 EBSP(Electron Back Scattered 測量，藉由測量存在於進行測量之觀察面之結晶粒 位，進行定向之有無之評估。在此方位解析中，由 測相對於與燒結體方位解析面垂直之方向之結晶粒 傾斜量，因此，可評估結晶粒之定向狀態。在該方 (HKL) 他面之 於前述 述一面 內方向 c丄較 :時，與 亦可例 此定向 爲 0.4 5 I 〇 直之兩 c //= I 以上。 直之方 符合， 定向面 顯微鏡 Pattern) 子之方 於可觀 之c軸 位解析 -22 - 200923981 中，算出 0Αν=Σθη (Θ)/Ση (0)(式 1)。在此， Θ係表示與以燒結體構成之六方晶鐵氧體基板之方位解析 面垂直之方向與EBSP之測量點之六方晶鐵氧體基板之c 軸方向之方位角度差，η ( Θ )係表示顯示前述Θ之測量點 之數。又，Σ θ η( 0 ) 、Ση( 0 )係表示分別在從〇至90°之 區間，加上相對於所有61之0 η( 61 ) 、η( Θ )者。在無定 向、亦即各向同性情況下，0 AV爲45°。因而，若在觀察 面之基板之一面之ΘΑν超過45°，c軸即定向於該面之面 內方向。較佳爲藉令前述平均方位差 0AV在65°以上，c 面定向於與方位解析面垂直之方向，而構成該方向之磁導 率優異之六方晶鐵氧體基板。於此情況下，c >軸定向於與 前述方位解析面平行之方向，前述方位解析面成爲c軸定 向面。再者，若以ηΑν=Ση(</))/ηι (式2)(然而，0 係表示將c軸方向之前述方位解析面之投影方向與前述方 位解析面內之一直線之方位差採正銳角時之角度。I ( 0 ) 係表示顯示方位差之測量點數，m係顯示在0〜9 0 °間分 割之點數。）賦與之測量點數之平均値除S D = { Σ ( η ( 0 ) -nAV ) 2/m } 1/2(式3 )所賦與之標準偏差SD之値SD/Nav 在0.6以下，即保證c軸隨機地轉向與c軸定向面並行之方 向。而且’前述一直線亦可爲在前述方位解析面內任一者。 藉由如此進行，在與c軸定向面平行之方向，亦可獲得高 磁導率。而且，由於S D爲測量點數越多則越大之値，因此， 爲可比較不同之測量點數之EBSP解析之諸結果，指標乃使 用以相當於平均測量點數之數N a v除之指標。n a v較佳設 -23 - 200923981 定在 nAV 導率 磁導 對於 上。 徑爲 解析 粒徑 具通 位解 先測 後稱 β i 爲止 面形 値， 導率 之電 性係 量至 作。 4000左右。藉由令平均方位差ΘΑν在65°以上’ SD/ 在0.6以下’與c軸定向面垂直之方向之100kHz之磁 可在30以上’與c軸定向面平丨了之方向之l〇〇kHz之 率可在8以上，與c軸定向面平行之方向之磁導率相 與c軸定向面垂直之方向之磁導率的比可在〇·15以 該比較佳在〇 · 2 0以上。而且’ E B S Ρ之評估使用光束 1 μιη者，以1 μιη跨距測量來進行即可。解析區域爲於 區域內包含40個以上之結晶粒，亦可依結晶粒之平均 ，在0.01〜0.3xl0-6m2之範圍內選擇，而在本發明中， 用性之條件係採用0.1 6x1. 0-6m2之解析區域，進行方 析。 ' 試料之一方向之磁導率可用以下所述方法評估。於預 量磁導率之環形高M鐵氧體製作氣隙，進行捲繞（之 爲軛部）。在例如以下之實施例中，轭部使用在丨〇 〇 k H z = 8100之Mn-Zn鐵氧體。標準試料準備具磁導率至6〇 之已知磁導率之材料’在加工成軛部之氣隙部位與截 狀一致後’插入至氣隙部位，測量l〇〇kHz中之電感 作成磁導率與電感値之校正曲線。將在此要測量之磁 未知之試料加工成同樣地位在氣隙部位，測量1 感L，對照校正曲線’算出磁導率。磁導率之頻率特 製作環形試料’以阻抗言十429 1 B ( Agilent公司製）測 10MHz 〜1 , 8GHz。 /、方晶鐵氧體鐵芯可使用習知之粉末冶金方法來製 又在/λ方晶鐵氧體鐵芯使用已定向之z型鐵氧體等 -24 - 200923981 情況下，六方晶鐵氧體鐵芯可如以下進行而獲得。燒結在 一方向磁場中將具易磁化面之六方晶鐵氧體之粉末成形而 得之成形體，獲得定向之六方晶鐵氧體。一方向磁場中之 成形可在直流靜磁場中進行加壓成形。於此情況下，所獲 得之六方晶鐵氧體係獲得C面於施加磁場方向平行地對 齊，C軸各向同性地轉向與該方向垂直之面內方向者。而 且，在六方晶鐵氧體之粉末形狀爲於C面方向平坦之板狀 等形狀之異向性大情況下，根據橫磁場成形（加壓方向與 磁場施加方向垂直），亦可藉由加壓成形，使C軸定向於 一方向之加壓方向。又，根據直磁場成形（加壓方向與磁 場施加方向平衍），C面於施加磁場方向平行地對齊，另 一方面，抑制c軸定向於特定方向。反之，上述z型鐵氧 體之定向亦可藉由於成形時，從加壓方向及垂直方向施加 旋轉磁場而進行。旋轉磁場之施加方法可爲使在一方向磁 場中，塡充有六方晶鐵氧體粉末之模具旋轉至加壓開始前 不久之方法，亦可爲使磁場施加裝置旋轉。又，亦可使用 可從複數個方向施加磁場之裝置，藉由切換電路’切換施 加磁場方向，施加旋轉磁場。如上述定向時’供成形之Z 型鐵氧體粉末較佳係含有許多單結晶粒之結構。因此’在 锻燒粉之狀態下進行反應，使結晶粒增大後’或者一次製 作燒結體後，將該等粉碎至單結晶粒之比例增多爲止’以 作爲Z型鐵氧體粉末亦可。又，芯形狀可從在前述步驟製 作之六方晶鐵氧體之燒結體塊以加工製作。或者’以芯形 狀之模具，製作芯單體之成形體，燒結，而製作。於此情 -25 - 200923981 況下，可減低加工成本。或者，於已粉碎之鍛燒粉混合、 混煉適度之水及有機黏合劑，以按壓成型製作成型體，燒 結，而製作。於此情況下’亦可減低加工成本。於按壓成 形情況下’在與按壓方向垂直之截面、亦即與鐵氧體之貫 穿孔垂直之截面內’具有緣端部中結晶方位之C軸之定向 與在截面內部中定向不同之特徵。因此，按壓成形之鐵氧 體鐵芯之磁通漏磁少’結果，可獲得具有高阻抗特性之線 圈元件。 實施例 以Fe2〇3、BaCCh、CoO (使用C〇3〇4)爲主成份，分別 ，秤量出 70.2 mol%、18.8 mol%、11.〇mol %，對此主成份， 分別添加 Mn3〇<t3.0 質量 ％，Li2C〇3〇.4 質量 ％，Si〇2〇.13 質 量％，以濕式球磨機混合16小時。而且，關於Mn3Ch、 Li2C〇3、 Si〇2 ’亦可於锻燒後進行之粉碎時添力口 。接著，將 此在大氣中以1 2 0 0 °C鍛燒2小時。以濕式球磨機將此鍛燒 粉粉碎1 8小時。於所製作之粉碎粉添加黏合劑（PVa ), 造粒。造粒後’壓縮成形’此後’在氧氣體環境中以1300 °C燒結3小時，而獲得Z型鐵氧體燒結體（第一比較例）。 使用盤式粉碎機，對以與上述相同條件獲得之Z型鐵 氧體燒結體進行粗粉碎，以振動磨粉碎所獲得之粗粉碎 粉，而獲得BET法之比表面積爲108 m/kg之Z型鐵氧體粉 末。於所得之粉末添加水及lwt %之PVA，製作鐵氧體黎， 在旋轉磁場中進行濕式成形。施加磁場爲〇 · 5 M A / m。在氧 中以1 3 0 0 °C燒結所得之成形體3小時，而獲得面定向型之 -26- 200923981 Z型鐵氧體之燒結體。定向度以Lotgering法評估，獲得 f=0.84之筒定向度（第一實施例）。進—步，使用上述漿， 於與加壓方向垂直之方向施加直流磁場，而濕式成形。施 加fe場爲0 · 8 4 M A / m。在氧中以1 3 1 0 °C燒結所得之成形體3 小時’而獲得一方向定向型Z型鐵氧體之燒結體（第二實 施例）。以顎式壓碎機將所得之燒結體粉碎，以盤式磨進 行粗粉碎’而獲得粗粉碎粉。進一步，以振動磨粉碎粗粉 碎粉’以球磨機將已經以振動磨粉碎之粉體粉碎2小時5 〇 分，而獲得BET法之比表面積爲2350 m2/kg之Z型鐵氧體 之粉末。於所得之粉末添加水及1 wt %之PVA ,製作鐵氧 體漿，於與加壓方向垂直之方向施加一軸性之直流磁場， 而濕式成形。施加磁場爲0·84 MA/m。在氧中以1300 °C燒 結所得之成形體3小時，而獲得一方向定向型之z型鐵氧 體之燒結體（第三實施例）。比較用試料準備Νΐ-Ζη鐵氧 體燒結體作爲比較用試料（第二比較例）。 將如此製作之第一比較例及第二比較例之燒結體之特 性顯示於表1 ’將起始磁導率之頻率特性顯示於第3圖。而 且，起始磁導率係製作環狀試料，以阻抗計429 1 Β ( AgUent 公司製）測量至10 MHz〜1.8 GHz。又，將第--第三實施 例之定向Z型鐵氧體之特性顯示於表1，將起始磁導率之 頻率特性與無定向之Z型鐵氧體之特性比較，顯示於第4 圖。就表1中有關第一比較例、第二實施例、第三實施例 ，表示以X射線繞射評估之定向度而言，分別以f C丄表 示定向磁場施加方向之c軸定向度，以f c //L (分別與 -27 - 200923981 加壓方向' 磁場施加方向成直角之方向）、f C //P (加壓 方向）表示直角方向之C軸配定度。定向之第--第三實 施例之Z型鐵磁顯示在1 GHz爲1 5以上之起始磁導率，爲 第一比較例之無定向Z型鐵氧體之1.5倍以上。在面定向 之第一實施例之Z型鐵氧體中，在磁場施加方向之i oomHz 之磁導率顯示磁場直角方向之9倍以上之磁導率。又，一 方向定向之第二' 第三實施例之Z型鐵氧體顯示磁場施加 方向之磁導率爲磁場直角方向之2倍以上、3倍以上之磁 Γ' 1 導率。體積電阻率皆爲2〜8χ104Ω . m，相當高。特別是於 粉末之比表面積高至2 3 00m2/kg以上，燒結體密度亦高至 5.0xl03(kg/m3)以上之第三實施例中，顯示在10MHz爲40 以上之高起始磁導率。而且，以X射線繞射評估之定向度 亦爲0.66，可知顯示高定向度。藉由使Z型鐵氧體定向， 起始磁導率可在一直維持高頻特性下’大幅提高。從第3 圖及第4圖可知，藉由使用z型鐵氧體，在高頻之磁導率 r 可較Ni-Zn鐵氧體大幅提高。又，藉由定向，可在一直維 持頻率特性下，謀求高磁導率化。 -28 - 200923981 表1 密度 103(kg/m3) (100MHz) β'\ (1GHz) 定向度 f c丄 f c//L f c//P 第一比較例 5.16 16.7 10.4 0.21 0,52 1.12 比較例2 4.95 13.4 4.4 _ _ 第一實施例 (面定向） c面定向方向 (磁場施加方向） 5.00 28.9 21.8 — — — C軸定向方向 (磁場直角方向） 3 — 第二實施例 (一方向定向） C面定向方向 (磁場施加方向） 5.14 29.6 20.2 0.41 0.48 1.81 C軸定向方向 (磁場直角方向） 12.5 7.5 第三實施例 (一方向定向） C面定向方向 (磁場施加方向） 5.05 42.7 17.6 0,66 4.46 1.85 C軸定向方向 (磁場直角方向） 11.6 6.76 接著，就第一比較例、第二比較例、第三實施例之z 型鐵氧體，製作第1圖構造之共模濾波器，將測量共模雜 規哀減量之結果顯不於第5圖。外形尺寸爲2x1x1.5mm。Z 型鐵氧體之厚度爲0.5mm，導線係使用直徑〇.〇3mm之絕緣 包覆銅線，捲繞數爲4次。而且，共模雜訊衰減量與差動 信號之損失分別與S參數成以下之關係。 共模雜訊衰減量[dB]=-20 log丨Scc21 | 差動信號損失[dB]=-20 log I Sdd21 I 使用第一比較例之Z型鐵氧體燒結體之共模濾波器相 較於使用N i - Ζ η鐵氧體之情形，在1 G Η z之共模雜訊衰減量 提高2 d Β。相對於此，使用一方向定向之第三實施例之ζ 型鐵氧體燒結體之共模濾波器獲得2dB良好之共模雜訊衰 -29 - 200923981 減特性。又’使用面定向之第一實施例之Z型鐵氧體燒結 體之共模濾波器獲得4 d B良好之共模雜訊衰減特性。 分別對具有第2圖所示之構造，貫穿孔之角形爲直角 之共模濾波器及圓弧形之共模濾波器，調查了濾波器特 性。外形尺寸爲2x1.2x1.2mm，貫穿孔之尺寸爲1.0x0.3mm。 導線之直徑爲0.03mm，捲線數爲4圈。所評估之圓弧狀半 徑 r 爲 0.015mm、0.03mm、0.09mm 及 0.15mm。該等圓弧狀 半徑r相當於貫穿孔之截面矩形之短邊之長度之5%、10 %、30%及50%，相當於長邊之1.5%、3%、9%及15%。 又，六方晶鐵氧體鐵芯使用結晶方位之c軸定向於前述貫 穿孔之貫穿方向，在與貫穿孔之貫穿方向垂直之面內具有 高磁導率之定向之Z型鐵氧體。在100MHz之面內起始磁 導率爲3 7。於第8圖顯示共模雜訊衰減量之評估結果。而 且，在第8圖中，0 %情形與5 %情形之圖表幾乎重疊。相 對於圓弧狀半徑r爲貫穿孔截面之矩形短邊之長度之〇% (角形爲直角情形）、5%、10%、30%及50%情形下’在 1.6GHZ之共模雜訊衰減量分別爲28.0 dB、27.9 dB、28.4 dB、 29.4 dB及30.0 dB。可知在5%，無法發揮令角部呈圓弧狀 之實質效果，藉由在10%以上，可改善共模雜訊衰減量。 再者，可知在30%以上，共模雜訊衰減量進一步提高。並 且可知在令矩形貫穿孔之角部呈圓弧狀’特別在1 GHz周邊 之頻帶，可提高雜訊衰減量。 接著’就具有第2圖所示之構造，貫穿孔尺寸不同之 兩種共模濾波器，調查濾波器特性。外形尺寸爲2 x 1 ·2 x -30 - 200923981 1.2mm。貫穿孔尺寸爲 l_Ox〇.lmm(Nol)匕 1.0x0.3mm(No2)。 由於捲線之平均線距爲0 · 1 8 m m，因此與繞組軸垂直之方向 之貫穿孔之寬度分別爲平均線距之0.5 6倍、1 · 6 7倍。又， No 1及N〇2之共模濾波器皆具有六方晶鐵氧體鐵芯之結晶 方位之c軸定向於與前述貫穿孔之貫穿方向之定向性，其 磁導率特性具有在與貫穿孔之貫穿方向垂直之面內具高磁 導率之面內異向性，在1 00MHz之面內起始磁導率爲24、 37。於第9圖及第10圖顯示共模雜訊衰減量及差動信號之 損失之評估結果。藉由使用定向性高，磁導率高之六方晶 鐵氧體鐵芯，且使貫穿孔之寬度大至0.1mm〜〇.3mm，可改 善共模誰訊衰減量及差動信號損失。 接著’評估使用以按壓成形製作之六方晶鐵氧體鐵芯 之共模濾波器。首先，以球磨機粉碎鍛燒粉，乾燥後，一 面於所得之粉體添加結合劑及水，一面混煉，製作。以按 壓成形機按壓所得之鐵氧體胚體，製作成形體，燒結該成 形體’而獲得六方晶鐵氧體芯。成形以外之步驟與第一實 施例相同。於所得之六方晶鐵氧體鐵芯施行捲線，而獲得 第1 3圖所示形狀之共模濾波器（n 〇 3 )。第1 3圖所示之形 狀之導線5 2、5 3於六方晶鐵氧體鐵芯5 1之封裝面側捲繞， 繞組部5 4之位置與第6圖所示之結構不同，其他則與第6 圖所不之結構相问。而且，尺寸爲橫1.9mm，高度1.2mm， 貫穿孔方向之長度爲1.2mm。又，貫穿孔孔形爲l.lmmx 0.4mm之矩形。爲供比較，從不磁場定向而製作之燒結體 塊切割加工相同尺寸之芯，製作相同形狀之共模濾波器 200923981 (N〇4 )。於第1 1圖顯示評估該等共模濾波器之雜訊衰減 量之結果。可知以按壓成形製作之共模濾波器之共模雜訊 衰減量優異。而且’在與N〇3之六方晶鐵氧體鐵芯之貫穿 孔之內側面相對之外側面進行X射線繞射時，c面之（^ 之峰値強度相對於與c面垂直之（1 1 〇 )之峰値強度比工 (0 0 1 8 ) /1 ( 1 1 0 )爲〇. 7 6，大於各向同性時之峰値強度比 0.2，可知c面定向於該外側面之面方向。而且，由於因按 壓成形時之壓力及模具面之作用導致機械定向，因此外側 面之其他面及內側面皆顯示相同之定向性。 【圖式簡單說明】 > 第1圖係顯示本發明線圈組件之一實施形態者。 第2圖係顯示本發明線圈組件之另一實施形態者。 第3圖係顯示鐵氧體之磁導率之頻率相關性者。 第4圖係顯示鐵氧體之磁導率之頻率相關性者。 第5圖係顯示共模濾波器之特性者。 第ό圖係顯示本發明線圈組件之另一實施形態者。 第7圖係顯示本發明線圈組件之另一實施形態者。 第8圖係顯示共模濾波器之特性者。 第9圖係顯示共模濾波器之特性者。 第1 0圖係顯示共模濾波器之特性者。 第1 1圖係顯示共模濾波器之特性者。 第1 2圖係顯示六方晶鐵氧體鐵芯之定向狀態者。 第1 3圖係顯示本發明線圏組件之另一實施形態者。 -32 - 200923981 【主要元件 符 號 說 明 ] 1 第 — 鐵 氧 體 2 第 二 鐵 氧 體 3 繞 組 部 4 緣 部 5 緣 部 6 導 線 7 導 線 8 端 子 電 極 9 端 子 電 極 10 端 子 電 極 11 端 子 電 極 21 -JU- 方 晶 鐵 氧 體 鐵 心 22 腳 部 23 繞 組 部 24 貫 穿 孔 25 腳 部 3 1 方 晶 鐵 氧 體 鐵 心 32 繞 組 部 33 導 線 34 導 線 35 貫 穿 孔 36 端 子 電 極 37 端 子 電 極 -33 200923981 38 端 子 電 極 39 端 子 電 極 4 1 方 晶 鐵 氧 體 鐵 心 42 -B3- 穿 孔 5 1 1 - 方 晶 鐵 氧 體 鐵 -++- 心 52 導 線 53 導 線 54 繞 組 部 12 1 結 晶 Ψ-Ι- 枚 -34BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil assembly excellent in high-frequency impedance characteristics, and more particularly to a coil assembly used as a transformer or a common mode filter. [Prior Art] The speed of signal transmission of electronic devices such as personal computers and mobile terminals is increasing, and the frequency of driving frequencies is increasing. For example, IEEE1394a with a transmission speed of 400Mbps or USB2.0 with a transmission speed of 480Mbps has been widely used, and it is also facing higher speed HDMI (700Mbps) and IEEE1394b (80000Mbps). Coil components such as common mode filters used for such high speed differential transmission are required to respond to high frequencies, small sizes, and the like. For example, Patent Document 1 discloses a high frequency common mode filter. Patent Document 1 discloses that a magnetic shielding portion having a relative magnetic permeability lower than that of the core 1 is provided between the edges of both ends of the core 1 for winding, and the impedance can be increased at a high frequency. [Patent Document 1] Japanese Laid-Open Patent Publication No. 2003-1 686 No. 1 SUMMARY OF THE INVENTION According to Patent Document 1, a common mode filter having a high frequency at a high impedance can be obtained. However, the conventional coil assembly disclosed in the above Patent Document 1 has a narrow band and therefore a non-preferred structure, once the impedance of the tube frequency is increased. Therefore, it is desirable to increase the impedance of the coil assembly regardless of the structure. Accordingly, it is an object of the present invention to provide a coil component that exhibits excellent characteristics in a high frequency band. The coil assembly of the present invention is characterized in that it comprises a hexagonal ferrite core, a pair of conductors wound around the hexagonal ferrite core, and a surface of the hexagonal ferrite core formed in the previous 200923981, and the conductor is connected a terminal electrode; the hexagonal ferrite core has a winding portion for winding the pair of conductors, and an initial magnetic permeability of the winding direction of the conductor of the winding portion is greater than at least perpendicular to the winding axis The initial permeability in one direction. Since the hexagonal ferrite core has a magnetic anisotropy in which the direction perpendicular to the C axis is the easy magnetization surface, the orientation is increased to increase the initial magnetic permeability, and high impedance can be obtained. If such a structure in which the direction of the initial magnetic permeability is used as the winding axis of the conductor is applied to the common mode filter, the amount of common mode noise attenuation in the high frequency band can be improved. Further, preferably, in the coil unit, the winding portion has a starting magnetic permeability in a direction perpendicular to the winding axis and is a direction substantially equal to an initial magnetic permeability of the winding axial direction. According to this configuration, the amount of noise attenuation in the high frequency band can be effectively improved. Further, in the above coil assembly, the hexagonal ferrite core preferably has a through hole, and a portion of the periphery of the through hole serves as the winding portion, and the conductor is wound through the through hole ', and the terminal The electrode is formed on a surface at least parallel to a through direction of the through hole of the hexagonal ferrite core. According to this structure, the magnetic flux leakage can be more suppressed, and the amount of noise attenuation can be further improved. Further, in the coil assembly, the other direction is preferably a direction perpendicular to a through direction of the through hole and a direction perpendicular to the winding axis. According to this configuration, since the initial magnetic permeability increases in the direction around the through hole, the amount of noise attenuation in the high frequency band can be effectively improved. Further, in the above-described wire front assembly having a through hole, the other direction may be a through direction of the through hole. In particular, it is preferable to replace the hexagonal ferrite core with the hexagonal ferrite core in order to replace the magnetic winding direction of the through hole with the winding direction. This is because, in the present case, the entire magnetic path direction is also along the direction in which the initial magnetic permeability is high. Therefore, another coil component of the present invention is characterized in that it comprises a hexagonal iron core and is wound around the hexagonal ferrite. a pair of conductors and a surface of the hexagonal ferrite core, and a terminal connecting the conductors, wherein the hexagonal ferrite core has at least a portion of the winding portion of the winding of the pair of conductors The C-axis of the crystal orientation is oriented in an in-plane direction that is approximately perpendicular to the winding axis of the conductor. According to this structure, the initial magnetic permeability around the axial direction is increased, and the noise of the high frequency band can be effectively improved. Further, in the above coil assembly, it is preferable that the winding portion has a C-axis of the orientation oriented in a direction perpendicular to a direction perpendicular to a winding axis of the conductor. According to this configuration, the amount of sag of the high frequency band can be effectively improved. Further, in the above coil assembly, the winding portion preferably has a C-axis in a direction oriented on a surface in a normal direction. According to this structure, the noise reduction of the local frequency band is also effectively improved. Further, in the coil unit, the hexagonal ferrite core has a through hole, and a part of the periphery of the through hole serves as the portion, and the conductor is wound through the through hole ', and the terminal is electrically formed At least the surface of the hexagonal ferrite core parallel to the through hole of the hexagonal ferrite core, the winding portion is such that the C axis of the crystal orientation is a direction in which the through hole is oriented. According to this structure, since the surrounding body is surrounded by the hole, the oxygen is formed at the pole; the front and the front, the volume of the attenuating crystal inside the noise crystal can have a better winding pole shape to the front side 200923981 The initial permeability is increased, so 'the noise reduction in the high frequency band can be effectively improved. Further, in the above-mentioned coil assembly, the hexagonal ferrite core preferably has a beak hole 'as a portion around the through hole as the winding portion, and the through hole will be described as a conductor. Winding, the terminal electrode is formed on at least a surface parallel to a direction in which the through hole of the hexagonal ferrite core is parallel, and an inner side surface of the hexagonal ferrite core on the through hole side and The C-axis of the crystal orientation of the inner side opposite the outer side is oriented in the normal direction of the inner side or the outer side, respectively. According to this configuration, since the initial magnetic permeability in the direction around the through hole is increased, the amount of noise attenuation in the high frequency band can be effectively improved. Further, in the above-described hexagonal ferrite core having a through hole, the hexagonal ferrite core preferably has a shape which does not substantially change in the through direction in a cross-sectional shape perpendicular to the through-direction. This structure is excellent in mass productivity because the hexagonal ferrite core can be produced in a simple manner. Further, the shape in which the cross-sectional shape does not substantially change in the above-described penetration direction means that the difference in the rounded corners of the corner portion of the hexagonal ferrite core can be tolerated. Further, in the above coil assembly, the hexagonal ferrite core is preferably in the shape of a rectangular parallelepiped. The use of a rectangular parallelepiped hexagonal ferrite core is advantageous for the low profile and miniaturization of the coil assembly. Further, in the coil assembly, the shape of the hole of the through hole is preferably a rectangle, and each corner portion of the rectangle has an arc shape, and a radius of the arc of the corner portion is a length of a rectangular short side direction of the cross-sectional shape of the through hole. More than 10%. Root 200923981 According to this structure, the amount of noise attenuation can be further improved. Further, in the coil unit, the hole shape of the through hole is preferably a rectangular shape, and a width of the through hole perpendicular to the winding axis is equal to or larger than an average winding distance of the pair of conductors. This structure contributes to the improvement of noise attenuation and signal loss. Further, each of the above structures may be combined as appropriate. According to the present invention, it is possible to provide a coil unit which exhibits excellent characteristics in a high frequency band. (Embodiment) Hereinafter, embodiments of the coil component of the present invention will be specifically described, and the present invention is not necessarily limited to the embodiment. In the respective embodiments, the same members are denoted by the same reference numerals. Fig. 1 shows a coil assembly of the present invention. A diagram of the structure of a winding type common mode filter according to an embodiment. Fig. 1(a) is a perspective view, and Fig. 1(b) shows a part of a bottom view of the inner side of the edge. The coil assembly of the present invention a hexagonal ferrite core, a pair of conductors wound around the hexagonal ferrite core, and a terminal electrode formed on the surface of the hexagonal ferrite core and connected to the conductor, which can be used as a surface mount type The coil assembly can be used. An I core or a roller core can be used to form an open magnetic circuit, and a closed magnetic circuit can be formed. Fig. 1 shows a common mode filter with a closed magnetic circuit structure with less leakage flux. The coil assembly is not limited to a total The analog filter can also be applied to other filters and transformers. It can also be used to limit the number of wires to a pair of wires, and the structure described below can be used not only for the use of a pair of wires, but also for A coil assembly for using a wire such as an inductor or a wafer bead. 200923981 Winding a wire 6, 7 as a pair of wires in a winding portion 3 of a first ferrite 1 constituting a hexagonal ferrite core. A wire made of a material having a small specific resistance such as copper may be used for insulating the insulating material such as a thin resin film, and the conductor may be formed by a film process or a printing process. The pair of conductors may be, for example, a common mode. In the case of Bo Yi, the loss of the differential signal for particularly reducing the commercial frequency is preferably wound approximately in parallel with a certain line spacing. One end of the rectangular winding portion 3 is disposed in a direction perpendicular to the winding axis and is mutually The rectangular parallelepiped portion 4 projecting in the opposite direction. The edge portion 5 is also disposed at the other end of the winding portion 3. The direction perpendicular to the winding axis of the winding portion 3 and the edge portions 4, 5 (the direction perpendicular to the direction in which the edge protrudes) In the same width, the first ferrite is formed into a columnar body having a slightly 截面-shaped cross section. Further, the shape of the winding portion is not limited to a rectangular parallelepiped shape, and may be a cylindrical shape or the like. Further, the winding portion 3 and the edge portions 4 and 5 are formed. Winding axis vertical Although the direction (the y direction in the drawing) does not have to be the same width, the productivity can be further improved by the shape of the same width. The upper end of the edge portions 4, 5 at both ends of the winding portion is fixed to the flat shape. The ferrite 2 is disposed opposite to the winding portion 3. The material is resin or the like, and in order to improve the efficiency of the magnetic circuit, the adhesive layer is preferably thin. The terminal electrodes 8 to 1 are formed under the edge portions 4 and 5 as The external electrode may be formed by sintering a silver paste, or may be formed by coating a paste of silver powder on the thermosetting resin and then thermally hardening. One end of the wire 6 is connected to the terminal electrode 8 and the other end is connected to Terminal electrode 110. One end of the wire 7 is connected to the terminal electrode 9, and the other end is connected to the electrode 11. Moreover, the terminal electrode is formed not only on the lower surface side of the package surface but also on the surface as shown in Fig. 1. The entire side of the vertical. -10- 200923981 The first ferrite 1 and the second ferrite 2 use a hexagonal ferrite having a magnetic permeability and an anisotropic crystal orientation. . This hexagonal ferrite has an easy magnetization surface. Soft ferrites such as Z-type ferrite, Y-type ferrite, and W-type ferrite are used. Among them, since the Z-type ferrite has a high magnetic permeability in a high frequency band of about 1 GHz, it is preferable. The hexagonal ferrite which is an easy magnetization surface in a direction perpendicular to the c-axis can be oriented to increase the magnetic permeability. In this case, the magnetic permeability in the direction parallel to the easy magnetization surface is increased. In the embodiment of Fig. 1, using the hexagonal ferrite thus oriented, the X-direction initial permeability μ x of the winding axis of the wire of the winding portion 3 of the first ferrite is larger than the winding axis Permeance in the direction perpendicular to / / y, # Z. In the case of constituting the coil unit, since the hexagonal ferrite core used in the coil unit secures the winding region and is easily formed in the winding axial direction, the magnetic path in the direction becomes long. Therefore, by increasing the magnetic permeability in this direction, the noise attenuation characteristics up to the high frequency can be obtained. Further, the second ferrite may have a direction in which the magnetic permeability is increased in the X direction which is the winding axis direction, or a direction in which the edge portion perpendicular to the winding axis protrudes. Further, the ferrite 2 may be a magnetic material different from the ferrite 1. By using a high magnetic permeability NiZn ferrite or MnZn ferrite, the impedance at a low frequency can be increased to obtain a noise attenuation characteristic at a low frequency. A hexagonal ferrite having an orientation state in which the initial magnetic permeability /X of the X direction is larger than the magnetic permeability # y, / / ζ perpendicular to the winding axis direction, the hexagonal crystal in a magnetic field in one direction The hexagonal crystal sintered body obtained by firing a ferrite powder obtained by molding a molded body is realized. The 1 2 ( a ) diagram shows a pattern diagram of its orientation state. In this case, since the crystal grains 1 2 1 of the flat hexagonal ferrite-11-200923981 body are oriented in an easy-to-magnetize surface (c-plane) which coincides with the plate surface in the drawing, and a direction, that is, a magnetic field application direction ( The X direction) is parallel, so the magnetic permeability in this direction can be increased. On the other hand, since the easy magnetization surface randomly faces the plane direction (yz direction) perpendicular to the direction, it is found that the magnetic permeability of the high magnetic permeability c in the in-plane direction and the low magnetic permeability in the C-axis direction are equal. 'It is possible to suppress the extreme decrease in the magnetic permeability in the direction of the face. When the field direction of the magnetic permeability is used as the winding axis, the c-axis of the crystal orientation of the winding portion 3 is oriented in the in-plane direction which is approximately perpendicular to the winding axis of the conductor. That is, the effect of the above structure using the direction of increasing the magnetic permeability is such that the c-axis of the crystal direction of the winding portion of the hexagonal ferrite core wound with a pair of conductors is oriented approximately perpendicular to the winding axis of the conductor. It is realized in the state of the in-plane direction. The structure for increasing the magnetic permeability of the winding axial direction of the winding portion is preferably one of a direction perpendicular to the winding axis of the conductor of the winding portion 3 of the first ferrite constituting the hexagonal ferrite core. The initial magnetic permeability is smaller than the initial magnetic permeability of the winding axis, and the initial magnetic permeability in the other direction perpendicular to the winding axis is approximately equal to the initial magnetic permeability of the winding axis. The structure having the initial magnetic permeability in the direction perpendicular to the winding axis and the initial magnetic permeability of the winding axial direction being approximately equal is applied when the rotating magnetic field is used as the hexagonal ferrite powder. A magnetic field or the like that is achieved when the crystal grain plane of the hexagonal ferrite is oriented. The 1 2 (b) diagram shows a pattern of the orientation state. Since the orientation of the easy magnetization surface is aligned with the plane direction perpendicular to the axis (y direction) of the rotating magnetic field, the magnetic permeability in the in-plane direction (zx direction) is increased. In this case, the c-axis is oriented in the axial direction of the rotating magnetic field (y-direction -12-200923981 direction). On the other hand, the magnetic permeability in the direction other than the inside of the plane (e.g., the y direction) is lowered. When the application surface of the rotating magnetic field is arranged in parallel with the winding axis of the conductor, that is, the winding axis (X direction) of the winding portion 3 of the first ferrite constituting the hexagonal ferrite core is started. The magnetic permeability is at least greater than the initial permeability of one direction perpendicular to the winding axis (for example, the y direction), and the initial permeability of the other direction (for example, the z direction) perpendicular to the winding axis of the conductor. The initial magnetic permeability of the aforementioned winding axis is approximately equal. In this case, the surface including the winding axis and the other directions described above corresponds to the aforementioned rotating magnetic field applying surface. Further, the other direction is a direction in which the first ferrite and the second ferrite are connected to the opposite direction (z direction) of the first ferrite 1 and the second ferrite 2, that is, the edge portion. Since the magnetic path direction in the first ferrite body can completely utilize the direction in which the magnetic permeability is high, it is particularly suitable because the magnetic flux leakage can be suppressed. The c-axis of the winding portion is oriented in a particular direction by using surface-oriented hexagonal ferrite ferrite. If the other direction is the relative direction (z direction) of the first ferrite and the second ferrite, the c-axis of the crystal orientation of the winding portion 3 is oriented approximately perpendicular to the winding axis, and is first The relative direction (z direction) of the ferrite and the second ferrite is approximately one direction perpendicular to the vertical direction. That is, the effect of the above structure using the magnetic permeability for increasing the plane orientation can be oriented at a c-axis of the crystal orientation of the winding portion 3 to be approximately perpendicular to the winding axis, and opposite to the first and second directions (z direction). It is implemented in a state of approximately one vertical direction. A second embodiment of the coil assembly of the present invention will be described with reference to Fig. 2'. Fig. 2 is a view showing the configuration of the second embodiment of the coil unit of the present invention -1 3 - 200923981. Fig. 2(a) is a perspective view, and Fig. 2(b) shows a portion of the bottom portion on the inner side of the edge portion. Portions having the same functions as those of the first embodiment are denoted by the same reference numerals. In the second embodiment, the hexagonal ferrite core 21 has a through-hole 24 . A portion of the periphery of the through hole 24 is used as a winding portion, and the winding conductors 6, 7 are passed through the through hole 24. The terminal electrode is formed on the lower side parallel to the penetration direction of the through hole 24 of the hexagonal ferrite core 21. Since the winding wire and the terminal electrode are the same as those of the first embodiment, a detailed description thereof will be omitted. The through hole 24 is formed by four perpendicularly intersecting planes having a rectangular cross section. A pair of wires are wound using one of four planes. Since the winding of the wire is a flat surface, the cross section of the through hole 24 does not have to be a rectangular shape as long as at least a part of the inner side surface is a flat surface. The winding portion 23 is approximately in the shape of a rectangular parallelepiped having one of the planes of the through holes 24 as one side. The hexagonal ferrite core 21 has a pair of leg portions 22, 25 at both ends of the winding portion 23, and protrudes from the opposite side of the through hole 24 with reference to the winding portion. Since the hexagonal ferrite core 2 1 constitutes a closed magnetic path, there is no non-magnetic gap between the materials and the like in the middle of the magnetic circuit, so that the efficiency of the magnetic circuit is high, and high noise attenuation characteristics can be obtained. Since the portion other than the hexagonal ferrite core is integrally formed in the same manner as the first embodiment, the configuration of the hexagonal ferrite used for the winding portion orientation and the effect thereof are the same as those of the first embodiment. Further, since the hexagonal ferrite core is integrally formed in the case of the second embodiment, the magnetic permeability and the orientation state of the winding portion 23 are continuously aligned with the entire hexagonal ferrite core 2 1 . status. For example, if the above-described plane oriented hexagonal ferrite core is used, the c-axis orientation of the crystallographic direction of the winding portion 23 is -14-200923981 in the through-hole direction, that is, the initial permeability The other direction approximately equal to the winding axis is a state in which the through-hole is penetrated and the direction perpendicular to the winding axis, that is, the direction of the circumference of the magnetic path coincides with the in-plane direction of the high initial permeability, and the magnetic path There is also no gap, so that the increase in the amount of noise attenuation is particularly effective. In the second embodiment, the cross-sectional shape of the hexagonal ferrite core 21 in the direction perpendicular to the penetration direction of the through-hole 24 is substantially unchanged in the above-described penetration direction. When the cross-sectional shape is constant, that is, it can be easily formed by press molding or press molding which can be pressed in one direction, so that productivity is further improved. Although this point is the same in the first embodiment, the number of components of the second embodiment is small, which is particularly suitable. Further, in the second embodiment, the pair of leg portions 22 and 25 have a rectangular shape in the y direction of the drawing, and the group of the terminal electrodes 8 and 9, 10, and 1 1 are formed in the same plane shape. The dicing machine can be formed to form a groove between the terminal electrodes 8 and 9 and between the terminal electrodes 10 and 1 1 so that the surfaces forming the terminal electrodes are independent. Although the above orientation can be performed by applying a magnetic field during molding, the orientation can be performed by press molding using the structure of the second embodiment. That is, the method of manufacturing the coil assembly may employ a method of pressing a hexagonal ferrite powder having an easy magnetization surface to form a second embodiment having a through hole, and obtaining a molded body 'sintering the molded body to obtain a sintered body. A method of obtaining a coil assembly by winding a wire through the through hole. When the axial direction (y direction) of the through hole 24 of the hexagonal ferrite core 21 of the second embodiment is pressed, the mechanical orientation by the pressing, the hexagonal crystal neodymium core 200923981 2 1 , the through hole The c-axis of the inner side of the inner side of the inner side or the outer side of the inner side or the outer side of the inner side of the outer side of the outer side of the outer side of the outer side of the outer side of the outer side of the outer side of the outer side of the outer side of the inner side or the outer side of the outer side. This orientation state is shown in the pattern diagram of Fig. 12(c). Chapter 1: The lower part of the figure shows the orientation of the windings. In this case, the group portion 23 views 'the display axis direction (the X direction) of the winding portion 23, and the direction of the initial conductivity of the temple is the direction of the through hole (y direction). . In the case of using a hexagonal iron core oriented with a rotating magnetic field surface, the entire orientation state of the winding portions is displayed. However, in the case of the mechanical orientation of the above press forming, the surface of the winding portion and a part of the group portion are Orientation. This tendency is not limited to the winding portion, but also appears on the peripheral surface and the outer surface of the coil surface. Since the direction of the constant magnetic permeability increases with the direction of the magnetic circuit of the coil assembly, it is suitable as the coil of the present invention. The core of the component. In particular, it is complementary to the hexagonal crystal core, which contributes to the productivity of the coil assembly. Moreover, the orientation of the surface of the hexagonal ferrite core and the internal orientation of the hexagonal ferrite core can also be achieved by the combination of the press forming and the magnetic field orientation. For example, the surface of the cubic ferrite core is in the aforementioned orientation state, and the inside is oriented in the above-described orientation or plane orientation, and magnetic flux leakage can also be suppressed. Further, the first and/or second ferrite of the embodiment shown in Fig. 1 is also in an oriented state in which the press forming is performed. In the case of using iron oxide obtained by press molding, the c-axis having the crystal orientation of the winding portion is oriented in the normal direction. In this case, in terms of the faces of the first ferrite and the second ferrite, the c-plane is oriented parallel to the face, and therefore, the magnetic anisotropic square line 1(c) is wound up. Wearing a square oxygen, in the direction of the perforation, and the change in ferrite characteristics, the six parties can be attached to the table according to the situation. Force, -16- 200923981 is better to honing the surface. In order to avoid such surface honing or the like, it is particularly preferable to apply the formed orientation state to the integral hexagonal ferrite core having a through hole as shown in Fig. 2. Further, the embodiment shown in Fig. 6 (third embodiment) may be used as a hexagonal ferrite core integrally formed (i.e., as a single member), and has a through-hole embodiment. The hexagonal ferrite core 3 1 of the embodiment shown in Fig. 6 differs from the embodiment shown in Fig. 2 in that there is no protrusion corresponding to the leg portion, and the shape is seen from the through direction of the through hole 35. Rectangular, the whole shape is a rectangular parallelepiped. In the case of the embodiment of Fig. 6, the winding portion 3 2 is formed on the side opposite to the side of the package surface on which the terminal electrode 36 is formed via the rectangular through hole 35. Both ends of the conductors 33, 34 wound around the winding portion 32 are connected to the terminal electrodes 36 to 39 (not shown) around the side faces (not shown) of the hexagonal ferrite core 31. Further, 'on the side of the hexagonal ferrite core 31, the terminal electrodes 36 to 39 may be extended to the upper side opposite to the package surface, and on the upper side, the wires 3 3, 34 may be connected to the terminal electrodes. 3 6 to 3 9. The frame-integrated hexagonal ferrite core having no protrusion corresponding to the leg portion is excellent in stability and mass productivity, and is advantageous for down-turning and miniaturization of the coil unit. Further, in the embodiment shown in Fig. 6, the shape of the hexagonal ferrite core viewed from the through direction of the through hole also includes the shape of the through hole 'symmetric with respect to the center line parallel to the package surface, because There is no need to distinguish the direction of the hexagonal ferrite core from the process, so the mass production can be improved. Further, the configuration in which the projection portion is not equivalent to the leg portion can be applied to the case where the hexagonal ferrite core is formed of a plurality of ferrites as in the embodiment of Fig. 1. 200923981 In Fig. 7, a fourth embodiment in which the shape of the through hole is different from that of the embodiment shown in Fig. 2 is shown. In the embodiment shown in Fig. 7(a), the hole shape of the through hole 42 is a rectangle, and each corner portion of the rectangle has an arc shape. Fig. 7(b) is an enlarged view of the through hole 42. That is, the cross-sectional shape of the through hole, that is, the hole shape is a rectangle in which an arc is disposed at an angle. In the case where a plurality of ferrites are used to form a hexagonal ferrite, a gap can be easily formed in the bonded portion, and the magnetic resistance is increased. In view of this, by making the corner portions of the rectangular through-holes 42 of the hexagonal ferrite cores 4 integrally formed in an arc shape, the magnetic resistance can be reduced, and the inductance can be improved. In the case of, for example, a common mode filter, the amount of noise attenuation can be increased. In this case, it is particularly preferable that the corner portions of the hexagonal ferrite core have a circular arc shape in a rectangular outer shape viewed from the through hole. Since the size of the arc shape is too small, the effect of the arc-shaped characteristic cannot be fully exerted. Therefore, in the case where the arc-shaped radius r is an arc-shaped portion, the radius r is preferably in the through hole. The length of the rectangular shape in the cross-sectional shape is 10% or more. In the through hole, when the corner portions are formed in an arc shape, since the arcuate portion is higher than the plane of the winding portion, it is also possible to use a spacer which separates the conductor from the side surface of the through hole when the winding is performed. In this case, the radius r preferably exceeds the radius of the conductor. Further, when it exceeds 50%, the through hole is not rectangular, and the uniformity of the magnetic circuit of the hexagonal ferrite core is broken. Therefore, the radius r is preferably 50% or less. Further, since the portion in which the conductor can be uniformly wound is reduced when the arc-shaped portion is excessively large, it is preferably 3 to 20% of the length of one side of the through hole of the winding portion. Moreover, the arc shape does not have to be a complete arc shape, as long as the length of the straight portion which disappears along the arc-shaped portion along one side of the winding portion of the through-hole section is -18-200923981 is the aforementioned arc-shaped radius r can be. Further, the arcuate angular shape can be grasped in the projection shape when the through hole is viewed from the through direction. As in the structure of Fig. 1, although the hexagonal ferrite core is formed by different members (i.e., plural members), arcs cannot be formed at the four corners of the hole portion, but can be formed by using One of the through-hole hexagonal ferrite cores can be provided with arcs at the four corners of the hole portion. In particular, in the case of using an integrated hexagonal ferrite core, even if the burrs of the cylindrical honing, bead blasting, etc. are performed to remove the flash or the angle of the contact portion of the conductor, the rectangular through hole is the fourth The arc of the corner of the corner does not disappear. On the other hand, in the case of using a non-integrated hexagonal ferrite core, the ferrites constituting the hexagonal ferrite core are honed and then bonded to form a core. The hole portion forms a wedge-shaped gap that is opposite to the outside. Therefore, the integrated hexagonal ferrite core is suitable for the common mode filter produced by the above honing. Further, in the case where the hole shape of the through hole is rectangular, the width in the direction perpendicular to the winding axis of the through hole is preferably equal to or larger than the average pitch of the pair of conductors. The average spacing is the average of the line spacings p of the windings shown in Figure 7. Further, the interval d shown in Fig. 7 is the center interval of each of the conductors constituting the pair of conductors. By increasing the width of the through hole, signal loss can be reduced. This is based on the following reasons. For example, in the case of using a coil component as a common mode filter, most of the high-frequency magnetic fields of the differential signal are mutually canceled by the alignment lines, and one of the remaining portions is eliminated in the magnetic field of the adjacent pair of lines, and further, The magnetic field generates magnetic losses inside the ferrite, which increases signal loss. By making the distance between the upper ferrite and the winding wire larger than the distance between adjacent wires, the strength of the ferrite inside the residual magnetic field is weakened by the adjacent pair of lines 200923981, and the loss is reduced, thereby reducing the loss. Reduce signal loss. Since the 'fee is increased when the width of the through hole is increased, the inductance is lowered if a conventional Ni-Zn neodymium magnet having a low magnetic permeability is still used when the noise attenuation of the tube band related to the GHz band is required. It is not possible to obtain a characteristic sufficient as a common mode filter. For this, since a hexagonal ferrite core having an orientation-increasing magnetic permeability is used, a sufficient inductance can be ensured. Therefore, the width of the through-hole can be increased. Further, the structure related to the circular arc shape of the corner portion of the through hole or the structure related to the width of the through hole can be widely applied to the rectangular shape regardless of the presence or absence of the foot or the orientation of the hexagonal ferrite. Through hole. As the hexagonal ferrite core used in the present invention, a sintered core of a Z-type ferrite, a Y-type ferrite, a W-type ferrite or the like can be used. The hexagonal ferrites can be selected according to the frequency domain of the frequency used. According to the order of the Z-type ferrite and the Y-type ferrite, the initial magnetic permeability up to the high frequency can be maintained. Among them, since the Z-type ferrite can maintain the initial magnetic permeability up to 1 GHz, and the initial magnetic permeability is the highest among the above hexagonal ferrites, it is suitable to set the frequency band of 1 GH or more. A coil assembly such as a common mode filter used. In the case of the Z-type ferrite, it is preferred that the C磁2Z type represented by Ba3C〇2Fe24〇4 has excellent high-frequency characteristics of the initial magnetic permeability. The Z-type ferrite does not have to be a single phase. The Z-type ferrite has a case in which a hetero phase is contained, and the present invention also allows the case 'including a dissimilar phase to be referred to as a Z-type ferrite. However, in order to obtain a high initial magnetic permeability, it is preferred to use a Z-type ferrite as a main phase. The Z-type ferrite is the main phase system. In the powder X-ray diffraction, the peak of the peak intensity is the Z-type ferrite. -20- 200923981 Here, the orientation of the hexagonal ferrite is further detailed. By increasing the direction of the initial magnetic permeability by the orientation as the winding axial direction of the coil, it is advantageous to reduce the total magnetic resistance and ensure high impedance. As described above, the Z-type ferrite or the Y-type ferrite has an orientation of easy magnetization toward the magnetic anisotropy perpendicular to the C-axis, and can be oriented. Therefore, the c-axis of the crystal direction can be oriented in the one-plane direction, and as described above, the initial permeability is anisotropic. Further, since the high-frequency characteristics can be prevented from being lowered by the orientation, the initial magnetic permeability is greatly increased, so that the inductance up to the high frequency can be obtained, and the noise attenuation characteristics up to the high frequency can be obtained. . The state in which the c-axis of the hexagonal ferrite is oriented in the in-plane direction of the substrate can be evaluated by X-ray diffraction. When the surface index of the diffraction peak is (HKL), the diffraction peak intensity Ihk of the specific surface (hkO) parallel to the c-axis is performed on the X-ray diffraction of one side of the substrate. The diffraction peak intensity I〇 with a specific plane (001) perpendicular to the c-axis <n ratio hko/I. ^ When the X-ray diffraction is performed on the other side, the C-axis is oriented in the inner side of the aforementioned side. The degree of orientation of the neodymium magnet in which the c-axis is oriented in one plane is determined as follows. In the X-ray diffraction pattern of one side of the hexagonal ferrite substrate measured in the range of 20 = 20 to 80°, the integrated intensity sum of all the diffraction peaks of the hexagonal ferrite is Σ I (HKL) (however, I (HKL) shows the integral intensity of the diffraction peak expressed by the index (HKL)), so that the integral intensity of all (ΗΚ0) diffraction peaks of L = 0 is Σ I ( HK0 In the case, the degree of orientation fc丄 assigned by fc丄=ς I ( HK0 ) / Σ I ( HKL ) is obtained. Here, I ( Hkl ) is the integral of the range of 0 (HKL) - 〇 .4 ° to θ + 0.4 ° when the peak angle of the 200923981 peak of the (HKL) plane is 0 (HKL). . If the degree of orientation f c 丄 is greater than the degree of orientation f c 算出 calculated from its X-ray diffraction, it can be said that the c-axis is oriented in one direction. Further, the above-described degree of orientation f c 丄 indicates that the orientation of the c-axis in the front inner direction is remarkable. When the aforementioned side of the case is the C-axis orientation surface, the degree of orientation f in the C-axis orientation surface is preferably 0.4 or more. When the degree of orientation f c 前述 is 0.4, the magnetic permeability in the direction perpendicular to the plane in which the X-ray diffraction is performed by _t is particularly high, and f ' ' obtains a magnetic permeability of 30 or more as at 100 kHz. Moreover, the face having the degree is referred to as a c-axis oriented face. More preferably, when the orientation degree fc 丄 or more is obtained, magnetic permeability of 35 or more is obtained, and for better release, at least in a plane perpendicular to the c-axis alignment plane and perpendicular to each other (hereinafter referred to as a vertical plane) In the equation, the degree of orientation fc calculated from f (00 18) / 1 (110) of the X-ray diffraction is preferably 0.3. The orientation degree fc / / indicates that the c-axis is oriented perpendicular to the vertical plane. More grain. This is ensured that the C-axis is randomly steered by at least two faces perpendicular to each other. By doing so. High magnetic permeability can also be obtained in the direction parallel to the C axis. Further, in the case where the object to be evaluated is small, EBSP (Electron Back Scattered measurement) can be performed in the scanning electron (SEM) observation, and the presence or absence of orientation can be evaluated by measuring the crystal grain position existing on the observation surface on which the measurement is performed. In this azimuth analysis, the amount of tilt of the crystal grain with respect to the direction perpendicular to the azimuth analysis plane of the sintered body is measured, and therefore, the orientation state of the crystal grain can be evaluated. On the side of the side (HKL) When the direction c丄 is more than: when, the orientation may be 0.4 5 I 〇 straight two c //= I or more. Straight square conformity, orientated surface microscope Pattern) The sub-square is resolved in the considerable c-axis position -22 - 200923981 In the equation, 0 Α ν = Σ θ η (Θ) / Σ η (0) (Formula 1) is calculated. Here, the lanthanum indicates the azimuthal angle difference between the direction perpendicular to the azimuthal analysis plane of the hexagonal ferrite substrate formed of the sintered body and the c-axis direction of the hexagonal ferrite substrate at the measurement point of the EBSP, η ( Θ ) It is the number of measurement points showing the aforementioned enthalpy. Further, Σ θ η( 0 ) and Ση( 0 ) are expressed in the range from 〇 to 90°, and η( 61 ) and η( Θ ) are added to all of 61. In the case of no orientation, i.e., isotropic, 0 AV is 45°. Therefore, if the ΘΑν of one surface of the substrate on the observation surface exceeds 45°, the c-axis is oriented in the in-plane direction of the surface. Preferably, the average azimuth difference 0AV is 65° or more, and the c-plane is oriented in a direction perpendicular to the azimuthal analysis surface to constitute a hexagonal ferrite substrate having excellent magnetic permeability in the direction. In this case, the c > axis is oriented in a direction parallel to the azimuth plane, and the azimuth plane is a c-axis directional plane. Furthermore, if ηΑν=Ση( </))/ηι (Expression 2) (However, 0 represents an angle at which the projection direction of the azimuth analysis plane in the c-axis direction and the azimuth difference of one of the straight lines in the azimuth analysis plane are at an acute angle. I ( 0 The system indicates the number of measurement points showing the difference in orientation, and m indicates the number of points divided between 0 and 90 °.) The average of the number of points to be measured is divided by SD = { Σ ( η ( 0 ) - nAV ) 2 /m } 1/2 (Formula 3) The standard deviation SD is SD/Nav below 0.6, which ensures that the c-axis is randomly turned in parallel with the c-axis orientation surface. Further, the aforementioned straight line may be any of the azimuth analysis faces. By doing so, a high magnetic permeability can also be obtained in the direction parallel to the c-axis orientation surface. Moreover, since SD is larger as the number of measurement points is larger, the index is used to compare the results of EBSP analysis of different measurement points, and the index is divided by the number N av corresponding to the average number of measurement points. . n a v is better set -23 - 200923981 is set at nAV conductivity permeance for . The diameter is the analytical particle size. The first solution is called β i until the surface shape is 先, and the electrical conductivity of the conductivity is determined. Around 4000. By making the average azimuth difference ΘΑν above 65° 'SD/ below 0.6', the magnetic force of 100 kHz perpendicular to the c-axis orientation surface can be more than 30 ' kHz in the direction parallel to the c-axis orientation surface The ratio may be 8 or more, and the ratio of the magnetic permeability in the direction parallel to the c-axis orientation surface to the direction perpendicular to the c-axis orientation surface may be 〇·15 or more preferably 〇·20 or more. Moreover, the evaluation of 'E B S 使用 is performed using a beam of 1 μιη, measured with a 1 μηη span. The analysis region is such that the crystal particles are contained in the region, and may be selected in the range of 0.01 to 0.3×10 −6 m 2 according to the average of the crystal grains. In the present invention, the condition of the use is 0.1 6×1. The analysis area of -6m2 is analyzed. The magnetic permeability in one direction of the sample can be evaluated by the method described below. An air gap is formed in a ring-shaped high M ferrite having a predetermined magnetic permeability, and is wound (as a yoke). In the following examples, for example, the yoke is made of Mn-Zn ferrite having 丨〇 〇 k H z = 8100. The standard sample preparation material with a magnetic permeability of 6 已知 of known magnetic permeability 'is inserted into the air gap after the air gap portion processed into the yoke is aligned with the truncated shape, and the inductance in l kHz is measured to be magnetic. Calibration curve for conductivity and inductance. The magnetically unknown sample to be measured here is processed into the same position at the air gap portion, and the inductance L is measured, and the magnetic permeability is calculated by comparing the calibration curve. The frequency of the magnetic permeability was measured to produce a circular sample of '10 MHz 〜1, 8 GHz by impedance 429 1 B (manufactured by Agilent). /, the square crystal ferrite core can be made using a conventional powder metallurgy method and in the case of /λ cubic ferrite core using oriented z-type ferrite, etc. -24 - 200923981, hexagonal ferrite The body core can be obtained as follows. The sintered body obtained by molding a powder of a hexagonal ferrite having an easy magnetization surface in a magnetic field in one direction is obtained to obtain an oriented hexagonal ferrite. Forming in a directional magnetic field can be pressure formed in a DC static magnetic field. In this case, the obtained hexagonal ferrite system obtains that the C plane is aligned in parallel with the direction of the applied magnetic field, and the C axis is isotropically turned to the in-plane direction perpendicular to the direction. Further, in the case where the powder shape of the hexagonal ferrite is large in the shape of a plate having a flat surface in the C-plane direction, the transverse magnetic field is formed (the direction of the pressurization is perpendicular to the direction in which the magnetic field is applied), and Press forming causes the C axis to be oriented in a direction of pressurization. Further, according to the forming of the direct magnetic field (the direction of the press is parallel to the direction in which the magnetic field is applied), the C faces are aligned in parallel with the direction of the applied magnetic field, and on the other hand, the c-axis is suppressed from being oriented in a specific direction. On the other hand, the orientation of the z-type ferrite may be performed by applying a rotating magnetic field from the pressing direction and the vertical direction during molding. The method of applying the rotating magnetic field may be a method of rotating the mold filled with the hexagonal ferrite powder in a one-direction magnetic field until the start of the pressurization, or rotating the magnetic field applying means. Further, a means for applying a magnetic field from a plurality of directions may be used, and the direction of the applied magnetic field is switched by the switching circuit to apply a rotating magnetic field. The Z-type ferrite powder for forming as described above preferably has a structure of a plurality of single crystal grains. Therefore, the reaction may be carried out in the state of the calcined powder to increase the crystal grains, or after the sintered body is produced once, and the ratio of the particles to the single crystal grains is increased until it is a Z-type ferrite powder. Further, the core shape can be processed from the sintered body block of the hexagonal ferrite produced in the foregoing step. Alternatively, a molded body of a core monomer is produced by a core-shaped mold and sintered. In the case of -25 - 200923981, the processing cost can be reduced. Alternatively, the pulverized calcined powder is mixed, kneaded with a moderate amount of water, and an organic binder, and the molded body is formed by press molding, and sintered to produce. In this case, the processing cost can also be reduced. In the case of press forming, 'the cross section perpendicular to the pressing direction, that is, the cross section perpendicular to the perforation of the ferrite' has a feature that the orientation of the C-axis in the edge portion is different from the orientation in the inside of the cross section. Therefore, the magnetic flux leakage of the formed ferrite core is small, and as a result, a coil component having high impedance characteristics can be obtained. EXAMPLES Fe2〇3, BaCCh, CoO (using C〇3〇4) were used as the main components, and 70.2 mol%, 18.8 mol%, and 11.〇mol% were weighed separately. For this main component, Mn3〇 was added. <t3.0 mass %, Li2C〇3〇.4 mass %, Si〇2〇.13 mass %, mixed in a wet ball mill for 16 hours. Further, Mn3Ch, Li2C〇3, and Si〇2' may be added to the pulverization after calcination. Next, this was calcined at 1,200 °C for 2 hours in the atmosphere. This calcined powder was pulverized in a wet ball mill for 18 hours. A binder (PVa) was added to the pulverized powder prepared, and granulation was carried out. After the granulation, 'compression molding' was thereafter sintered at 1300 ° C for 3 hours in an oxygen gas atmosphere to obtain a Z-type ferrite sintered body (first comparative example). The Z-type ferrite sintered body obtained under the same conditions as above was coarsely pulverized by a disc mill, and the obtained coarsely pulverized powder was pulverized by a vibration mill to obtain a specific surface area of the BET method of 108 m/kg. Type ferrite powder. Water and 1 wt% of PVA were added to the obtained powder to prepare ferrite, which was subjected to wet molding in a rotating magnetic field. The applied magnetic field is 〇 · 5 M A / m. The obtained shaped body was sintered at 1,300 ° C for 3 hours in oxygen to obtain a sintered body of the face-oriented type -26-200923981 Z-type ferrite. The degree of orientation was evaluated by the Lotgering method, and the degree of orientation of the cylinder of f = 0.84 was obtained (first embodiment). Further, using the above slurry, a DC magnetic field is applied in a direction perpendicular to the direction of pressurization, and wet forming is performed. The application field is 0 · 8 4 M A / m. The obtained molded body was sintered at 1 3 10 ° C for 3 hours in oxygen to obtain a sintered body of a directional oriented Z-type ferrite (second embodiment). The obtained sintered body was pulverized by a jaw crusher, and coarsely pulverized by a disc mill to obtain a coarsely pulverized powder. Further, the coarse powder was pulverized by a vibration mill. The powder which had been pulverized by a vibration mill was pulverized by a ball mill for 2 hours and 5 minutes to obtain a powder of a Z-type ferrite having a specific surface area of 2350 m2/kg by the BET method. To the obtained powder, water and 1 wt% of PVA were added to prepare a ferrite slurry, and a linear DC magnetic field was applied in a direction perpendicular to the direction of pressurization, followed by wet forming. The applied magnetic field was 0·84 MA/m. The obtained shaped body was sintered at 1300 °C for 3 hours in oxygen to obtain a sintered body of a directional type z-type ferrite (third embodiment). The Νΐ-Ζη ferrite sintered body was prepared as a comparative sample (second comparative example) for the comparative sample. The characteristics of the sintered bodies of the first comparative example and the second comparative example thus produced are shown in Table 1. The frequency characteristics of the initial magnetic permeability are shown in Fig. 3. Further, the initial magnetic permeability was measured by a resist sample of 429 1 Β (manufactured by AgUent Co., Ltd.) to 10 MHz to 1.8 GHz. Further, the characteristics of the oriented Z-type ferrite of the first to third embodiments are shown in Table 1, and the frequency characteristics of the initial magnetic permeability are compared with the characteristics of the non-oriented Z-type ferrite, which is shown in the fourth. Figure. With respect to the first comparative example, the second embodiment, and the third embodiment in Table 1, the degree of orientation of the X-ray diffraction evaluation is expressed by f C 分别 to indicate the c-axis orientation of the orientation magnetic field application direction, respectively. Fc //L (in the direction perpendicular to the direction in which the magnetic field is applied by -27 - 200923981, respectively), f C //P (pressurization direction) indicates the C-axis coordinate in the right-angle direction. The orientation-first Z-type ferromagnetic display shows an initial magnetic permeability of 1 5 or more at 1 GHz, which is 1.5 times or more of the non-oriented Z-type ferrite of the first comparative example. In the Z-type ferrite of the first embodiment of the plane orientation, the magnetic permeability of i oom Hz in the direction in which the magnetic field is applied shows a magnetic permeability which is 9 times or more in the direction perpendicular to the magnetic field. Further, the second direction of the second orientation of the Z-type ferrite of the third embodiment shows that the magnetic permeability in the direction in which the magnetic field is applied is two times or more and three times or more the magnetic Γ '1 conductivity in the direction perpendicular to the magnetic field. The volume resistivity is 2~8χ104Ω. m, which is quite high. In particular, in the third embodiment in which the specific surface area of the powder is as high as 2 3 00 m 2 /kg or more and the sintered body density is also higher than 5.0 x 10 3 (kg/m 3 ) or more, the initial magnetic permeability at 40 MHz or more is shown to be 40 or more. . Moreover, the degree of orientation evaluated by X-ray diffraction was also 0.66, and it was found that the degree of orientation was high. By orienting the Z-type ferrite, the initial magnetic permeability can be greatly increased while maintaining the high-frequency characteristics. As can be seen from Fig. 3 and Fig. 4, the magnetic permeability r at a high frequency can be greatly improved compared with Ni-Zn ferrite by using a z-type ferrite. Further, by orientation, high magnetic permeability can be achieved while maintaining the frequency characteristics. -28 - 200923981 Table 1 Density 103 (kg/m3) (100MHz) β'\ (1GHz) Orientation fc丄fc//L fc//P First Comparative Example 5.16 16.7 10.4 0.21 0,52 1.12 Comparative Example 2 4.95 13.4 4.4 _ _ First embodiment (plane orientation) c-plane orientation direction (field application direction) 5.00 28.9 21.8 — — — C-axis orientation direction (field direction) 3 – Second embodiment (one-direction orientation) C-plane orientation Direction (magnetic field application direction) 5.14 29.6 20.2 0.41 0.48 1.81 C-axis orientation direction (field direction) 12.5 7.5 Third embodiment (one-direction orientation) C-plane orientation direction (field application direction) 5.05 42.7 17.6 0,66 4.46 1.85 C Axis orientation direction (magnetic field orthogonal direction) 11.6 6.76 Next, in the first comparative example, the second comparative example, and the z-type ferrite of the third embodiment, a common mode filter of the first figure structure is fabricated, and the common mode impurity is measured. The result of the stipulation is not shown in Figure 5. The external dimensions are 2x1x1.5mm. The Z-type ferrite has a thickness of 0.5 mm, and the wire is insulated with a copper wire having a diameter of 〇.〇3 mm, and the number of windings is four. Moreover, the loss of the common mode noise and the loss of the differential signal are respectively related to the S parameter as follows. Common mode noise attenuation [dB] = -20 log 丨 Scc21 | Differential signal loss [dB] = -20 log I Sdd21 I Comparison of common mode filters using the Z-type ferrite sintered body of the first comparative example In the case of using N i - Ζ η ferrite, the attenuation of the common mode noise at 1 G Η z is increased by 2 d Β. On the other hand, the common mode filter of the ζ type ferrite sintered body of the third embodiment oriented in one direction is used to obtain a good common mode noise -29 - 200923981 decrement characteristic of 2 dB. Further, the common mode filter of the Z-type ferrite sintered body of the first embodiment of the surface orientation was used to obtain a good common mode noise attenuation characteristic of 4 d B . The filter characteristics were investigated for the common mode filter having a rectangular shape at the right angle of the through hole and the arc common mode filter having the structure shown in Fig. 2. The outer dimensions are 2x1.2x1.2mm and the through-hole dimensions are 1.0x0.3mm. The diameter of the wire is 0.03 mm and the number of winding wires is 4 turns. The evaluated arcuate radius r is 0.015 mm, 0.03 mm, 0.09 mm, and 0.15 mm. These arcuate radii r correspond to 5%, 10%, 30%, and 50% of the length of the short side of the cross section rectangle of the through hole, and correspond to 1.5%, 3%, 9%, and 15% of the long side. Further, the hexagonal ferrite core is oriented with the c-axis of the crystal orientation in the through-perforation direction, and has a Z-type ferrite having a high magnetic permeability in a plane perpendicular to the penetration direction of the through-hole. The initial permeability was 3 7 in the plane of 100 MHz. Figure 8 shows the evaluation results of the common mode noise attenuation. Moreover, in Fig. 8, the 0% case almost overlaps the chart of the 5% case. Relative to the arc-shaped radius r is the % of the length of the rectangular short side of the through-hole section (the angle is a right angle), 5%, 10%, 30%, and 50% of the common mode noise attenuation at 1.6 GHz. The reductions are 28.0 dB, 27.9 dB, 28.4 dB, 29.4 dB and 30.0 dB, respectively. It can be seen that at 5%, the substantial effect of making the corner portion arc-shaped cannot be exerted, and by 10% or more, the amount of common mode noise attenuation can be improved. Furthermore, it can be seen that the amount of common mode noise attenuation is further increased at 30% or more. Further, it can be seen that the corner portion of the rectangular through hole is formed in an arc shape, particularly in the frequency band around 1 GHz, and the amount of noise attenuation can be increased. Next, the structure shown in Fig. 2 was used, and two kinds of common mode filters having different through hole sizes were used to investigate the filter characteristics. Dimensions are 2 x 1 · 2 x -30 - 200923981 1.2mm. The through hole size is l_Ox〇.lmm(Nol)匕 1.0x0.3mm (No2). Since the average line pitch of the winding wire is 0 · 18 m m, the width of the through hole perpendicular to the winding axis is 0.5 6 times and 1.7 7 times the average line pitch, respectively. Moreover, the common mode filters of No 1 and N 〇 2 have the orientation of the c-axis of the crystal orientation of the hexagonal ferrite core oriented in the through-hole direction, and the magnetic permeability characteristic has The in-plane anisotropy of high magnetic permeability is perpendicular to the plane perpendicular to the through-hole, and the initial magnetic permeability is 24, 37 in the plane of 100 MHz. Figures 9 and 10 show the evaluation results of the common mode noise attenuation and the loss of the differential signal. By using a hexagonal ferrite core having a high orientation and a high magnetic permeability, and making the width of the through hole as large as 0.1 mm to 〇.3 mm, the attenuation of the common mode and the loss of the differential signal can be improved. Next, a common mode filter using a hexagonal ferrite core formed by press molding was evaluated. First, the calcined powder is pulverized by a ball mill, and after drying, a binder and water are added to the obtained powder, and the mixture is kneaded and produced. The obtained ferrite body was pressed by a press molding machine to prepare a molded body, and the formed body was sintered to obtain a hexagonal ferrite core. The steps other than the forming are the same as in the first embodiment. The obtained hexagonal ferrite core was subjected to winding, and a common mode filter (n 〇 3 ) having a shape shown in Fig. 3 was obtained. The wires 5 2, 5 3 of the shape shown in Fig. 3 are wound on the side of the package surface of the hexagonal ferrite core 5 1 , and the position of the winding portion 54 is different from that shown in Fig. 6, and others Asked about the structure of Figure 6. Further, the size was 1.9 mm in width and 1.2 mm in height, and the length in the direction of the through hole was 1.2 mm. Further, the through hole has a rectangular shape of l.lmm x 0.4 mm. For comparison, a sintered body made of no magnetic field orientation was cut into a core of the same size to produce a common mode filter of the same shape 200923981 (N〇4). The results of evaluating the noise attenuation of these common mode filters are shown in Figure 11. It is understood that the common mode filter produced by press molding has excellent common mode noise attenuation. Further, when X-ray diffraction is performed on the side opposite to the inner side surface of the through hole of the hexagonal ferrite core of N〇3, the intensity of the c-plane is perpendicular to the c-plane (1) The peak intensity ratio of 1 〇) is (0 0 1 8 ) /1 ( 1 1 0 ) is 〇. 7 6, the intensity ratio of the peak to the greater than isotropic is 0.2, the c-plane is oriented on the outer side. In addition, since the mechanical orientation is caused by the pressure at the time of press forming and the action of the mold surface, the other side and the inner side of the outer side surface exhibit the same orientation. [Simplified illustration] > The first figure shows the present One embodiment of the coil assembly of the invention is shown in Fig. 2. Fig. 2 shows another embodiment of the coil assembly of the present invention. Fig. 3 shows the frequency dependence of the magnetic permeability of the ferrite. Fig. 4 shows the ferrite. The frequency dependence of the magnetic permeability of the body. Fig. 5 shows the characteristics of the common mode filter. The figure shows another embodiment of the coil assembly of the present invention. Fig. 7 shows the coil assembly of the present invention. Another embodiment is shown in Fig. 8 which shows the characteristics of the common mode filter. The characteristics of the common mode filter are displayed. The 10th figure shows the characteristics of the common mode filter. The 1st figure shows the characteristics of the common mode filter. The 1st figure shows the hexagonal ferrite core. Fig. 13 shows another embodiment of the coil assembly of the present invention. -32 - 200923981 [Description of main component symbols] 1 - Ferrite 2 Second ferrite 3 Winding portion 4 Edge Part 5 Edge 6 Wire 7 Wire 8 Terminal electrode 9 Terminal electrode 10 Terminal electrode 11 Terminal electrode 21 -JU- Square ferrite core 22 Foot 23 Winding portion 24 Through hole 25 Foot 3 1 Square ferrite core 32 Winding section 33 Conductor 34 Conductor 35 Through hole 36 Terminal electrode 37 Terminal electrode -33 200923981 38 Terminal electrode 39 Terminal electrode 4 1 Square ferrite core 42 -B3- Perforation 5 1 1 - Square ferrite iron -+ +- heart 52 wire 53 wire 54 winding group 12 1 crystallization Ψ-Ι- piece -34