1224785 玖、發明說明 (發明說明應敘明：發明所屬之技術領$、㈣技術、内容、實施方式及圖式簡單說明） 【發明所屬之技術領城】 技術領域 本發明係有關於可改寫資訊之光磁記錄媒體及其製造 5 方法。 L· Jl 背景技術 對於光磁記錄媒體之資訊的記錄方式之一例為磁場調 變方式。依該磁場調變方式進行資訊記錄時，係將雷射光 10照射在光磁記錄媒體之記錄對象部份，並施加對應於寫入 資訊之磁場。在該方式中，光磁記錄媒體應具有可有效利 用磁場之構造為宜。 π、，不祖丹，取 15 20 磁性層者。如此之光磁記錄媒體曾記載於，例如，特開平 03-137837號公報上。前述公報所記載之光磁記錄媒體係 具有在iS製基板上依序積層軟磁性層、凹㈣成層、光磁 記錄層及保護層之構造。前述光磁記錄層係使磁化方向垂 直於該層之層，而資訊之記錄係藉由雷射光之照射以及磁 場之施加而控财述光磁㈣層之磁化方向來進行。前述 軟磁性層為，例如Ni_Fe合金製成，且與前述光磁記錄層 相異’磁化方向係平行於該軟磁性層。該軟 射法形成在前述基板上。 _ 二在於前述習知之光磁記錄媒體中，例如，由對向配置 在前述保護層之磁頭所產生的错 生的磁场係透過前述保護層、前 6 玖、發明說明 迷光磁兄錄層以及前述光硬化性樹脂層之後，朝與該層平 仃之方向進行而通過前述軟磁性層中度透過前述光 硬化1±樹脂層、前述光磁記錄層以及前述保護層而回到前 述磁頭。如此，藉由磁場形成閉環路，前述磁場乃有效作 5用於⑽對象部份，並適於進行資訊之記錄。 但是，在前述習知技術中，由於欲提高前述基板與前 述軟磁性層之密著性等的理由，前述基板是銘製的。另一 方面，1呂為較高價之材才斗，故使前述光磁記錄媒體之製造 成本變高。又，前述軟磁性層之形成係藉濺射法進行，因 10此，其設備之運轉或維護管理成本較高，並且前述軟磁性 層之材料對於前述基板之附著率也並不好，故其效率亦不 佳。 【發明内容】 發明概要 15 本务明之目的係提供能解決或減輕前述之課題的光磁 記錄媒體以及其製造方法。 依據本發明之第丨方面所提供之光磁記錄媒體之特徵 ’係在基板上依序積層有軟磁性層、凹執形成層及光磁記 錄層之光磁記錄媒體，而前述基板係由樹脂製成且至少在 20該基板之表面中與前述軟磁性層相接觸之部份的表面粗度 為4nm以上。 前述軟磁性層、前述凹軌形成層以及前述光磁記錄層 ’係分別設置在前述基板之兩面為宜。 珂述基板之表面整體係被前述軟磁性層被覆為宜。 7 玖、發明說明 前述軟磁性層之面積為記錄面之面積以上，並且在前 述基板之表面積的85%以下之範圍内為宜。 依據本發明之第2方面所提供的光磁記錄媒體之特徵 ’係係在基板上依序積層有軟磁性層、凹軌形成層及光磁 記錄層之光磁記錄媒體，而前述基板係由樹脂製成且至少 在該基板之表面中與前述軟磁性層相接觸之部份上形成多 數凹軌’且該部份之表面粗度為2ηηι以上。 前述多數凹執係形成在前述基板之兩面，並且前述軟 磁性層及前述光磁記錄層分別設置在前述基板之兩面為宜 〇 依據本發明之第3方面所提供之光磁記錄媒體之製造 方法，係在基板上依序積層有軟磁性層、凹執形成層，及 光磁記錄層之光磁記錄媒體的製造方法，該製造方法之特 徵在於包含有將前述基板以樹脂成形，並使其表面粗度成 為4nm以上之第丨程序，及藉無電解電鍍法形成前述軟磁性 層之第2程序。 則述第1程序係使用將其表面粗度調整成4nm以上之壓 模來進行為宜。 依據本發明之第4方面所提供之光磁記錄媒體的製造 方法係在基板上依序積層有軟磁性層與光磁記錄層，且 至少在前述基板之表面中與前述軟磁性層相接觸之部份形 成多數凹軌的光磁記錄媒體之製造方法，其特徵在於包含 切前述基板以樹脂成形，並使其表面粗度成為2細以上 之第1¾序’及藉無電解電鐘法形成前述軟磁性層之第2程 1224785 玖、發明說明 序0 w述第1程序係使用將其表面粗度調整成2nm以上之壓 模來進行為宜。 本發明之特徵以及優點可由下述之本發明實施態樣的 5 說明來了解。 圖式簡單說明 第1圖係顯示本發明之光磁記錄媒體一側之截面圖。 第2 A圖、第2B圖係說明第1圖所示之光磁記錄媒體之 製造方法之程序的截面圖。 10 第3A圖、第3B圖係說明第1圖所示之光磁記錄媒體之 製造方法之程序的截面圖。 第4圖係顯示本發明之光磁記錄媒體另一例之截面圖 〇 【實施方式 15 較佳實施例之詳細說明 以下，將參照圖式具體地說明本發明之較佳實施態樣 〇 第1圖係顯示本發明之光磁記錄媒體之一實施例。本 實施例之光磁碟片D1，具有在基板丨之上面la及下面113依 20序積層有軟磁性層2、凹執形成層3、光磁記錄層4及保護 層5之構造。該光磁碟片D1係使基板丨之上面la侧之構造與 基板1之下面1 b側夾住基板1而相互對稱。 基板1為，例如聚碳酸酯製成且具有中空環形圓板形 狀。該基板1之上下面la，lb之表面粗度為，例如5nm。於 9 1224785 玖、發明說明 本說明書中所謂之「表面粗度」係指於2〇〇1年之日本工業 規袼（JIS)預定義之「算術平均高度」。 軟磁性層2係由在較弱磁場磁化會有較大變化之高透 磁率材料所成，例如為Fe_Co_Ni合金製成者。軟磁性層2 5之磁化方向乃平行於該層，而軟磁性層2係可使由磁頭等 所產生之磁場，發揮有效作用於光磁記錄層4之記錄對象 部份的功效。於本實施例中，軟磁性層2覆蓋基板丨之表面 整體，且除了於基板丨之上下面1&，lb之外，亦形成在基 板1之外周面上及内周面上。 1〇 凹軌形成層3係由，例如，紫外線硬化樹脂所形成。 且在該凹執形成層3之上面及下面，於半徑方向上交互棑 列形成為延伸於圓周方向之多數凹執31及多數凸執32。在 本申請書所謂之「凹軌」及「凸執」係均不含光磁記錄層 4之概心。凹執3 1之寬度為，例如〇 · 5 ，而凸軌μ之寬度 15為，例如0·25叫1，而凸軌32之寬度為，例如〇·25μπι。又， 凹軌3 1之冰度為’例如4〇ηπι。 光磁记錄層4係具有強保磁力而成為資訊之記錄對象 之層。該光磁記錄層4，係具有在磁化方向相對於層為垂 直之垂直磁化層上組合介電體層及反射層等的構造，例如 20 ，由 AgpdCuSi 層、SiN 層、AgPdCuSi 層、GdFeCo 層、 TbFeCo層，以及siN層而成之多層構造。如此之多層構造 對於適▲進行資訊之記錄與再生十分適合。在本實施例中 ，光磁記錄層4係形成在基板丨之上下面la，lb，同時可讓 資訊記錄在凹執31上及凸軌32上之光磁記錄層4，且可謀 10 玖、發明說明 求資訊之大容量化。 保護層5為，例如透明之紫外線硬化樹脂製成。該保 護層5係可發揮防止光磁記錄層4之磨損或錢之功用者。 前述基板1及各層2〜5之厚度，例如，基板Wi2_ 、軟磁性層2為0.8μηι、凹執形成3為1〇叫、光磁記錄層μ 為125nm、保護層5為15，。而光磁記錄層4之厚度的内容 ，例如，AgPdCuSi層為 l〇nm、SiN層為 5nm、AgpdCuSw 為 3〇nm、GdFeCo層為 5nm、TbFeC〇層為 25nm，以及 層為50nm。 其次將說明光磁碟片D1之製造方法的一例。 首先，將基板1藉射出成型法進行樹脂成形。於該程 序中，如第2A圖所示，係使用例如，鎳製的一對壓模6。 壓模6於例如，氣體壓力15pa、RF電力lkw之條件下，施 行使氬氣離子衝擊表面之蝕刻處理約1〇分鐘，藉此使其表 面粗度形成為5nm。將一對壓模6裝設在模具7上，並在該 等一對壓模6之間填充已溶融之聚碳酸酯，然後，使其硬 化就能使基板1成形。 其-人，在基板1之表面整體形成軟磁性層2。該程序係 藉由無電解電鍍法來進行。例如，將基板丨依序予以浸潰 在氯化錫水溶液及氣化鈀水溶液之後，如第2B圖所示，在 含有Fe鹽、Ni鹽、Co鹽，及還原劑之無電解電鍍液L中， 浸潰約20分鐘，就能使軟磁性層2形成前述之厚度。 然後，在積層於基板丨之上下面“，lb的軟磁性層2上 ，形成凹執形成槽3。如第3 A圖所示，於該程序中係使用 玖、發明說明 例如，由石英玻璃構成之一對透明壓模8。在透明壓模8形 成有對應於多數凹執31及多數凸執32的預定凹凸圖案。於 形成凹執形成層3時，^ Η吏軟磁性層2之表面具有黏著性 ，乃在軟磁性層3塗布矽烷耦合劑，並在該軟磁性層2上配 5置未硬化之紫外線硬化樹脂。之後，與軟磁性層2隔著預 之間隔而將對透明壓模8被覆在前述紫外線硬化樹脂 上。接著從透明壓模8側照射紫外線而使前述紫外線硬化 樹脂硬化。其後，如第3Β圖所示，卸下透明壓模8。依如 此步驟就能形成凹執形成層3。 1〇 接著，將光磁記錄層4形成在凹執形成層3上。藉由以 例如，濺射法依序積層構成光磁記錄層4的多數層，就能 形成光磁σ己錄層4。之後，在該光磁記錄層4上形成保護層 5。將未硬化之紫外線線硬化樹脂藉，例如，旋塗法塗布 在光磁記錄層4上，然後，照射紫外線而使前述紫外線硬 15化樹脂硬化，就能形成保護層5。依前述一連串之作業程 序，就能獲得光磁碟片D1。 由於基板1為樹脂製成，其與軟磁性層2之密著性本來 就不是良好。但是，由於基板!之表面粗度為5nm，因此， 軟磁性層2之一部份就變成進入於基板丨之微小的凹部之狀 20態，乃使基板1與軟磁性層2之密著性變成良好。本發明人 製作表面粗度為種種粗度之多數聚碳酸醋製基板，並進行 檢測基板與軟磁性層之密著程度實驗的結果是，確認基板 之表面粗度若為4nm以上，則基板與軟磁性層可適當地密 著。 12 玖、發明說明 相較於習知技術所使 可使基板1之材料費較 因為基板1為樹脂製成，因此 用之例如，玻璃製或鋁製之基板， 低廉，且可降低製造成本。 丨王層2係以無電解電鍍法形成，因此，將 軟磁性層2 ’相較於以例如，濺射法形成之情形，係可使 製造設備簡易化且亦能使週轉資金減少。而且，並盔軟磁 性層2之材料對㈣板之㈣性不良的情形。這對於欲降 低製造成本方面是有用的。 另方面，本發明人對於如前述之兩面構造之光磁碟 片確認下述事項。 即’本發明人將變更對於聚碳酸醋製之基板的軟磁性 層之被覆率的後述之第丨至第5樣品，放置在8代、85· 之高溫高濕環境下1_小時以進行耐久性檢查。於該檢查 中發現由於基板吸收水分㈣基板與透水性低之軟磁性層 之間有水分滯留，使軟磁性層之表面祕且形成略呈半球 狀之凸部的缺陷。 本發明人所進行之檢查結果，如第1表所示。 第1表 樣品種類 對於基板之 軟磁性層的被覆率(〇/〇) 凸部之產生數/cm2 弟1樣品 100 0 第2樣品 95 34 第3樣品 90 7 弟4樣品 85 0 第5樣品 80 0 於此，第1樣品係與光磁碟片D1同樣將基板之表面整 IJ24785 玖、發明說明 肢以I人磁性層覆盍，並令前述被覆率為1〇〇%。第2及第3 木八π 口係例如’除去基板之外周面及内周面而僅在基板之上 下面積層軟磁性層者’並令前述被覆率分別為95%及 。第4及第5樣品係僅在除去基板之上下面的外周側緣部份 5及内周側緣部份之其他部份積層軟磁性層，並令前述被覆 率分別為85%及80%。如第！表所示，在第！、第4及第5樣 口口中，並未發現前述凸部。相對於此，在第3及第4樣品中 ，則到處可見前述凸部。由該檢查結果可了解，為防止前 述之缺陷，應將基板之表面整體被覆軟磁性層，或者，使 1〇軟磁性層之面積（基板與軟磁性層之接觸面積）為基板表面 積的85%以下較為適宜。即使使軟磁性層之面積為基板表 面積的85%以下，由於軟磁性層係具有可有效進行資訊之 。己錄的作用者’因此，亦應使軟磁性層之面積為光磁記錄 層之記錄對象部份的面積以上為宜。 15 其次’將參照第4圖說明對本發明有關之光磁記錄媒 體的另一實施例。在第4圖中，對於與前述實施例為同樣 或類似之要素，附予與前述實施例相同之符號。本實施例 之光磁碟片D2，其基板1之形狀與前述實施例相異。 在基板1之上面la及下面ib，於半徑方向上交互排列 20形成為延伸於圓周方向之多數凹軌11及多數凸軌。因此 ，在光磁碟片D2中，未設置相當於前述實施例之凹軌形成 層3。凹執11之底面U1&側壁面112之表面粗度為，例如 2nm。構成凸執12之平坦面121之表面粗度為，例如2nm。 以下將說明光磁碟片D2之製造方法之一例。 14 1224785 玖、發明說明 基板1，係藉使用鎳製的一對壓模之射出成型法成形 。在刖述一對壓模中，形成對應於多數凹執丨丨及多數凸軌 12的預定之凹凸圖案。該等一對壓模，乃於氣壓i 5pa、 RF電力lkW之條件下，施行使將氬氣離子衝擊於表面之餘 5刻處理、力5刀麵，藉此使其表面粗度成為2nm而形成者。表 面粗度係藉由前述餘刻處理時間予以調整，若將前述餘刻 處理日寸間lig短就月匕使表面粗度變小。冑前述一對壓模裝言史 於模具，並在該等一對壓模之間填充已溶融的聚碳酸醋， 之後，將其硬化就能成形基板1。在基板1上依序積層之軟 10磁性層2、％磁記錄層4，w及保護層5，係藉由與前述實 施例同樣之作業程序形成。如此，可獲得光磁碟片D2。 於光磁碟片D2中，基板丨之表面粗度為，例如2nm。 本發明人在與前述相同樣之實驗中，以光磁碟片〇2之構造 ，亦確認基板1之表面粗度若為2nm以上，則基板丨與軟磁 15性層2可適當地密著，因此，對於光磁碟片〇2而言，雖然 基板1亦為樹脂製成里，基板丨與軟磁性層2之密著性仍高 。與光磁碟片D1之情形作比較，雖基板丨之表面粗度較小 但基板1與軟磁性層2亦可適當地密著的原因可能是在基板 1之表面形成凹執U及凸執12 ’因此’不但使基板i與軟磁 20性層2之接觸面積變大，亦能獲得所謂之錨著效應之故。 本發明並不限定於前述實施例之内容。對於本發明有 關之光磁記錄媒體各部之具體性構成，可自由作種種之設 。十、欠更。同樣，對次本發明有關之光磁記錄媒體之製造方 法上的各作業程序之具體性構成亦可自由作種種之變更。 15 I?24785 玖、發明說明 例如，於前述兩種之光磁碟 ^ ^ ^ , 任種中，並不限定 ;土板之上下面將各層分別積 積層之兩面構造，亦可以是僅 在基板之單面積層各層之單面 在如此之構造的情形 ，則僅調整基板之單面的表面粗度即可。對於後者之光 磁碟片，凹軌或凸軌亦可以僅形成在基板之單面。基板可 μ是以聚碳㈣所形成者’亦可以環氧樹脂等其他樹脂 形成者。X ’資訊之記錄並㈣定料凹軌上及凸軌上之 光磁記錄層進行，亦可以僅對於其中一方進行。 【圖式簡孕^說^明】 第1圖係顯示本發明有關之光磁記錄媒體的一側之截 面圖。 第2Α圖、第2Β圖，係說明在第1圖所示之光磁記錄媒 體的製造方法之程序的截面圖。 第3 A圖、第3B圖，係說明在第i圖所示之光磁記錄媒 15體的製造方法之程序的截面圖。 第4圖係顯示本發明有關之光磁記錄媒體的他例之截 面圖。 16 1224785 玖、發明說明 【圖式之主要元件代表符號表】 1…基板 1 a…基板之上面 1 b…基板之下面 2···軟磁性層 3…凹執形成層 4…光磁記錄層 5…保護層 6…壓模 7…模具 8…透明壓模 11，31…凹軌 12，32···凸執 111…凹執底面 112…凹執側壁面 121…凸執平坦面 D1，D2···光磁碟片 171224785 发明 Description of the invention (The description of the invention should state: the technical collar of the invention, the simple description of the technology, content, implementation and drawings) [Technical collar to which the invention belongs] TECHNICAL FIELD The present invention relates to rewritable information 5 magneto-optical recording media and its manufacturing method. L · Jl Background Art An example of a method for recording information on a magneto-optical recording medium is a magnetic field modulation method. When information recording is performed according to the magnetic field modulation method, the laser light 10 is irradiated on the recording object portion of the magneto-optical recording medium, and a magnetic field corresponding to the written information is applied. In this method, it is preferable that the magneto-optical recording medium has a structure capable of effectively utilizing a magnetic field. π ,, not Zudan, take 15 20 magnetic layer. Such a magneto-optical recording medium has been described in, for example, Japanese Patent Application Laid-Open No. 03-137837. The magneto-optical recording medium described in the aforementioned publication has a structure in which a soft magnetic layer, a recessed layer, a magneto-optical recording layer, and a protective layer are sequentially laminated on a substrate made of iS. The aforementioned magneto-optical recording layer is a layer whose magnetization direction is perpendicular to the layer, and the recording of information is performed by controlling the magnetization direction of the magneto-optical layer by irradiation of laser light and application of a magnetic field. The soft magnetic layer is made of, for example, a Ni_Fe alloy, and is different from the magneto-optical recording layer. The magnetization direction is parallel to the soft magnetic layer. This soft shot method is formed on the aforementioned substrate. _ Second, in the conventional magneto-optical recording medium, for example, the stray magnetic field generated by the magnetic head facing the protective layer is transmitted through the protective layer, the first 6 玖, the description of the optical magnetic recording layer and the aforementioned After the photo-curable resin layer, the film is moved in a direction level with the layer, and the soft magnetic layer passes through the photo-hardened 1 ± resin layer, the photo-magnetic recording layer, and the protective layer to return to the magnetic head. In this way, by forming a closed loop with a magnetic field, the aforementioned magnetic field is effectively used for the target object and is suitable for recording information. However, in the conventional technique, the substrate is engraved for reasons of improving the adhesion between the substrate and the soft magnetic layer. On the other hand, 1 Lu is a relatively expensive material, which increases the manufacturing cost of the aforementioned magneto-optical recording medium. In addition, the formation of the soft magnetic layer is performed by a sputtering method. Therefore, the cost of operation or maintenance of the equipment is high, and the adhesion rate of the material of the soft magnetic layer to the substrate is not good. Efficiency is also poor. SUMMARY OF THE INVENTION An object of the present invention is to provide a magneto-optical recording medium capable of solving or alleviating the aforementioned problems, and a method for manufacturing the same. The feature of the magneto-optical recording medium provided according to the first aspect of the present invention is a magneto-optical recording medium in which a soft magnetic layer, a recessed formation layer, and a magneto-optical recording layer are sequentially laminated on a substrate, and the substrate is made of resin. The surface roughness of the part made to contact the aforementioned soft magnetic layer at least 20% of the surface of the substrate is 4 nm or more. The soft magnetic layer, the recessed track forming layer, and the magneto-optical recording layer are preferably provided on both sides of the substrate, respectively. The entire surface of the substrate is preferably covered with the soft magnetic layer. 7 发明 Description of the invention The area of the soft magnetic layer is greater than or equal to the area of the recording surface, and preferably within a range of 85% or less of the surface area of the substrate. The feature of the magneto-optical recording medium provided according to the second aspect of the present invention is a magneto-optical recording medium in which a soft magnetic layer, a recessed track forming layer, and a magneto-optical recording layer are sequentially laminated on a substrate, and the substrate is composed of A plurality of recessed rails are made of resin and formed on at least a portion of the surface of the substrate that is in contact with the aforementioned soft magnetic layer, and the surface roughness of the portion is 2ηη or more. The plurality of recesses are formed on both sides of the substrate, and the soft magnetic layer and the magneto-optical recording layer are preferably disposed on both sides of the substrate. A method for manufacturing a magneto-optical recording medium according to the third aspect of the present invention. A method for manufacturing a magneto-optical recording medium in which a soft magnetic layer, a recessed formation layer, and a magneto-optical recording layer are sequentially laminated on a substrate. The manufacturing method is characterized by including forming the substrate into a resin and forming the substrate. The surface roughness is a second procedure of 4 nm or more, and a second procedure of forming the aforementioned soft magnetic layer by electroless plating. The first procedure described above is preferably performed using a stamper whose surface roughness is adjusted to 4 nm or more. A method for manufacturing a magneto-optical recording medium according to the fourth aspect of the present invention is a method in which a soft magnetic layer and a photo-magnetic recording layer are sequentially laminated on a substrate, and at least the surface of the substrate is in contact with the soft magnetic layer. The manufacturing method of a part of the magneto-optical recording medium in which most of the concave tracks are formed is characterized in that it includes cutting the aforementioned substrate to form a resin, and making the surface roughness 1 to 2 ′ of 2 or more fines, and forming the aforementioned by an electroless clock method. The second step of the soft magnetic layer 1224785 (1), the description of the invention, the first procedure is performed using a stamper whose surface roughness is adjusted to 2 nm or more. The features and advantages of the present invention can be understood from the following 5 descriptions of the embodiments of the present invention. Brief Description of the Drawings Fig. 1 is a sectional view showing one side of the magneto-optical recording medium of the present invention. Figures 2A and 2B are cross-sectional views illustrating a procedure of a manufacturing method of the magneto-optical recording medium shown in Figure 1. 10 FIGS. 3A and 3B are cross-sectional views illustrating a procedure of a manufacturing method of the magneto-optical recording medium shown in FIG. 1. FIG. 4 is a cross-sectional view showing another example of the magneto-optical recording medium of the present invention. [Detailed description of the preferred embodiment of Embodiment 15 Hereinafter, the preferred embodiment of the present invention will be specifically described with reference to the drawings. An embodiment of the magneto-optical recording medium of the present invention is shown. The magneto-optical disc D1 of this embodiment has a structure in which a soft magnetic layer 2, a recessed formation layer 3, a magneto-optical recording layer 4 and a protective layer 5 are laminated on the upper surface 1a and lower surface 113 of the substrate 丨 in the order of 20. The magneto-optical disc D1 is configured such that the structure on the upper surface la side of the substrate 丨 and the lower surface 1 b side of the substrate 1 sandwich the substrate 1 and are symmetrical to each other. The substrate 1 is made of, for example, polycarbonate and has a hollow annular disk shape. The surface roughness of the upper and lower surfaces 1a, 1b of the substrate 1 is, for example, 5 nm. On 9 1224785, the description of the invention The "surface roughness" as used in this specification refers to the "arithmetic mean height" predefined by the Japanese Industrial Standards (JIS) in 2001. The soft magnetic layer 2 is made of a high-permeability material that undergoes a large change in magnetization in a weak magnetic field, such as a Fe_Co_Ni alloy. The magnetization direction of the soft magnetic layer 25 is parallel to this layer, and the soft magnetic layer 2 enables the magnetic field generated by the magnetic head and the like to exert an effect on the recording object portion of the magneto-optical recording layer 4 effectively. In this embodiment, the soft magnetic layer 2 covers the entire surface of the substrate 丨, and is formed on the outer peripheral surface and the inner peripheral surface of the substrate 1 in addition to the substrate 1 and the upper and lower surfaces 1 &, lb. The 10 groove forming layer 3 is formed of, for example, an ultraviolet curable resin. Further, on the upper and lower sides of the recess formation layer 3, a plurality of recesses 31 and a plurality of protrusions 32 are formed alternately in a radial direction so as to extend in the circumferential direction. The so-called "concave tracks" and "convex lines" in this application are not intended to include the magneto-optical recording layer 4. The width of the dimple 3 1 is, for example, 0.5, and the width 15 of the convex track μ is, for example, 0. 25 is called 1, and the width of the convex track 32 is, for example, 0.25 μm. The ice degree of the concave rail 31 is' e.g. 40nm. The magneto-optical recording layer 4 is a layer which has a strong coercive force and becomes a recording target of information. The magneto-optical recording layer 4 has a structure in which a dielectric layer and a reflective layer are combined on a perpendicular magnetization layer whose magnetization direction is perpendicular to the layer. Layer, and a multi-layer structure made of siN layers. This multi-layer structure is very suitable for recording and reproducing information. In this embodiment, the magneto-optical recording layer 4 is formed on the substrate 丨 above and below la, lb, and at the same time, information can be recorded on the magneto-optical recording layer 4 on the recess 31 and on the convex track 32, and can be 10 谋2. Description of the invention seek to increase the capacity of information. The protective layer 5 is made of, for example, a transparent ultraviolet curing resin. The protective layer 5 is used to prevent the abrasion or money of the magneto-optical recording layer 4. The thickness of the aforementioned substrate 1 and each of the layers 2 to 5, for example, the substrate Wi2_, the soft magnetic layer 2 is 0.8 μm, the recessed formation 3 is 10 μm, the magneto-optical recording layer μ is 125 nm, and the protective layer 5 is 15. The thickness of the magneto-optical recording layer 4 is, for example, an AgPdCuSi layer of 10 nm, a SiN layer of 5 nm, an AgpdCuSw of 30 nm, a GdFeCo layer of 5 nm, a TbFeC0 layer of 25 nm, and a layer of 50 nm. Next, an example of a manufacturing method of the magneto-optical disc D1 will be described. First, the substrate 1 is resin-molded by an injection molding method. In this procedure, as shown in Fig. 2A, for example, a pair of stampers 6 made of nickel are used. The stamper 6 is etched with an argon ion impact surface for about 10 minutes under the conditions of a gas pressure of 15 Pa and RF power lkw, thereby forming a surface roughness of 5 nm. A pair of stampers 6 is set on the mold 7, and the molten polycarbonate is filled between the pair of stampers 6, and then the substrate 1 is formed by hardening it. One of them is to form a soft magnetic layer 2 on the entire surface of the substrate 1. This procedure is performed by the electroless plating method. For example, after the substrate 丨 is sequentially immersed in an aqueous solution of tin chloride and an aqueous solution of vaporized palladium, as shown in FIG. 2B, in an electroless plating solution L containing Fe salts, Ni salts, Co salts, and a reducing agent, as shown in FIG. 2B. For about 20 minutes, the soft magnetic layer 2 can be formed into the aforementioned thickness. Then, a recessed groove 3 is formed on the soft magnetic layer 2 laminated on the substrate, "1b", "1b." As shown in FIG. 3A, in this procedure, 玖 is used, and the invention is described, for example, by quartz glass. A pair of transparent stampers 8 is formed. The transparent stamper 8 is formed with a predetermined concave-convex pattern corresponding to a plurality of recesses 31 and a plurality of protrusions 32. When the recessed formation layer 3 is formed, the surface of the soft magnetic layer 2 It has adhesiveness. It is coated with a silane coupling agent on the soft magnetic layer 3, and 5 uncured ultraviolet curable resins are arranged on the soft magnetic layer 2. Then, it is pressed against the transparent magnetic layer 2 with a predetermined interval. The mold 8 is coated on the ultraviolet curing resin. Then, the ultraviolet curing resin is cured by irradiating ultraviolet rays from the transparent stamper 8 side. Thereafter, as shown in FIG. 3B, the transparent stamper 8 is removed. In this way, it can be formed. Recessed formation layer 3. 10 Next, the magneto-optical recording layer 4 is formed on the recessed formation layer 3. For example, a plurality of layers of the magneto-optical recording layer 4 are sequentially laminated by a sputtering method to form light. The magnetic σ has been recorded in layer 4. Then, in this magneto-optical recording layer 4 A protective layer 5 is formed. The protective layer 5 can be formed by applying an unhardened ultraviolet curing resin to the magneto-optical recording layer 4 by, for example, spin coating, and then irradiating ultraviolet rays to harden the ultraviolet curing resin. According to the aforementioned series of operation procedures, the magneto-optical disc D1 can be obtained. Since the substrate 1 is made of resin, the adhesion between the substrate 1 and the soft magnetic layer 2 is not good. However, the surface roughness of the substrate! Is 5 nm. Therefore, a part of the soft magnetic layer 2 becomes a state of entering into a minute recessed portion of the substrate 丨, so that the adhesion between the substrate 1 and the soft magnetic layer 2 becomes good. The surface roughness of the inventor's production is Most of the polycarbonate substrates of various thicknesses were tested for the adhesion between the substrate and the soft magnetic layer. As a result, it was confirmed that the substrate and the soft magnetic layer could be properly adhered if the surface roughness of the substrate was 4 nm or more. 12 玖 Description of the invention Compared with the conventional technology, the material cost of the substrate 1 can be lower. Because the substrate 1 is made of resin, it is cheaper to use, for example, a glass or aluminum substrate.丨 The king layer 2 is formed by the electroless plating method. Therefore, compared with the case where the soft magnetic layer 2 ′ is formed by, for example, the sputtering method, the manufacturing equipment can be simplified and the working capital can be reduced. In the case where the material of the soft magnetic layer 2 does not have good resistance to the cymbal plate. This is useful for reducing the manufacturing cost. On the other hand, the inventor confirmed the following for the optical magnetic disc with the two-sided structure as described above. Matters: 'The present inventors will change the coverage of the soft magnetic layer of the substrate made of polycarbonate from the fifth to fifth samples described below, and place them in an 8th generation, 85 ° C high temperature and high humidity environment for 1_ hours A durability inspection was performed. In this inspection, it was found that moisture was trapped between the substrate and the soft magnetic layer having low water permeability due to the substrate's absorption of moisture, which caused the surface of the soft magnetic layer to be secret and to form a hemispherical convex defect. The test results performed by the inventors are shown in Table 1. Table 1 Sample type Coverage rate of the soft magnetic layer of the substrate (0 / 〇) Number of protrusions / cm2 Brother 1 sample 100 0 Brother 2 sample 95 34 Brother 3 sample 90 7 Brother 4 sample 85 0 Brother 5 sample 80 0 Here, the first sample is the same as that of the magneto-optical disc D1. The surface of the substrate is IJ24785 发明, the description of the invention is covered with a magnetic layer of I, and the aforementioned coverage is 100%. The 2nd and 3rd Machi ports are, for example, "a layer with a soft magnetic layer only above and below the substrate except the outer peripheral surface and the inner peripheral surface of the substrate", and the aforementioned coverage ratios are 95% and 5%, respectively. The fourth and fifth samples were laminated with the soft magnetic layer only on the outer peripheral side edge portion 5 and the inner peripheral side edge portion on the upper and lower sides of the substrate, and the aforementioned coverage ratios were 85% and 80%, respectively. As the first! As shown in the table! In the fourth, fifth, and fifth samples, the aforementioned convex portions were not found. On the other hand, in the third and fourth samples, the aforementioned convex portions are everywhere. It can be understood from the inspection results that in order to prevent the aforementioned defects, the entire surface of the substrate should be covered with a soft magnetic layer, or the area of the 10 soft magnetic layer (the contact area between the substrate and the soft magnetic layer) should be 85% of the surface area of the substrate The following is more appropriate. Even if the area of the soft magnetic layer is 85% or less of the surface area of the substrate, the soft magnetic layer has information that can effectively carry out information. Therefore, it is desirable that the area of the soft magnetic layer should be equal to or larger than the area of the recording target portion of the magneto-optical recording layer. 15 Next, another embodiment of the magneto-optical recording medium according to the present invention will be described with reference to FIG. In Fig. 4, elements which are the same as or similar to those of the previous embodiment are given the same symbols as those of the previous embodiment. The shape of the substrate 1 of the magneto-optical disc D2 of this embodiment is different from that of the previous embodiment. The upper surface 1a and the lower surface ib of the substrate 1 are alternately arranged 20 in the radial direction to form a plurality of concave rails 11 and a plurality of convex rails extending in the circumferential direction. Therefore, in the magneto-optical disc D2, the recessed track formation layer 3 corresponding to the foregoing embodiment is not provided. The surface roughness of the bottom surface U1 & side wall surface 112 of the recess 11 is, for example, 2 nm. The surface roughness of the flat surface 121 constituting the boss 12 is, for example, 2 nm. An example of a manufacturing method of the magneto-optical disc D2 will be described below. 14 1224785 发明 Description of the invention The substrate 1 is formed by injection molding using a pair of stampers made of nickel. In the pair of stampers described above, predetermined concave-convex patterns corresponding to the plurality of recesses and the plurality of projections 12 are formed. Under the conditions of air pressure i 5pa and RF power lkW, the pair of stampers are applied for 5 minutes to deal with argon ions impinging on the surface and force 5 blade surfaces, thereby making the surface roughness 2nm. Former. The surface roughness is adjusted by the above-mentioned remaining processing time. If the above-mentioned remaining processing time is short, the surface roughness will be reduced.胄 The aforementioned pair of stampers is installed in a mold, and the melted polycarbonate is filled between the pair of stampers, and then the substrate 1 is formed by hardening them. The soft magnetic layer 2, the magnetic magnetic recording layer 4, w, and the protective layer 5 which are sequentially laminated on the substrate 1 are formed by the same operation procedure as the previous embodiment. In this way, an optical magnetic disc D2 can be obtained. In the optical magnetic disc D2, the surface roughness of the substrate 丨 is, for example, 2 nm. In the same experiment as the foregoing, the inventor also confirmed that the substrate 1 and the soft magnetic 15 layer 2 can be properly adhered if the surface roughness of the substrate 1 is 2 nm or more with the structure of the magneto-optical disc 02. Therefore, for the optical magnetic disk 02, although the substrate 1 is also made of resin, the adhesion between the substrate 1 and the soft magnetic layer 2 is still high. Compared with the case of the magneto-optical disc D1, although the surface roughness of the substrate 丨 is small, the reason why the substrate 1 and the soft magnetic layer 2 can also be properly adhered may be the formation of a concave U and a convex on the surface of the substrate 1 12 'So' not only makes the contact area between the substrate i and the soft magnetic 20 layer 2 larger, but also obtains the so-called anchor effect. The present invention is not limited to the contents of the foregoing embodiments. Various specific configurations of the various parts of the magneto-optical recording medium related to the present invention can be freely made. Ten, owe more. Similarly, the specific structure of each operation procedure in the manufacturing method of the magneto-optical recording medium related to the present invention can be freely changed in various ways. 15 I? 24785 发明 Description of the invention For example, in the aforementioned two types of optical magnetic disks ^ ^ ^, any of them is not limited; the top and bottom of the soil plate are laminated on both sides of each layer, and it can also be only on the substrate In the case where the single surface of each layer of the single-area layer has such a structure, it is only necessary to adjust the surface roughness of the single surface of the substrate. For the latter optical magnetic disc, the concave or convex tracks may be formed only on one side of the substrate. The substrate may be formed of a polycarbonate, or may be formed of another resin such as epoxy resin. The recording of X 'information is performed on the magneto-optical recording layer on the concave track and on the convex track, or it can be performed only for one of them. [Schematic diagram ^ explanation ^ explanation] Fig. 1 is a sectional view showing one side of the magneto-optical recording medium according to the present invention. Figures 2A and 2B are cross-sectional views illustrating procedures of a method for manufacturing the magneto-optical recording medium shown in Figure 1. 3A and 3B are cross-sectional views illustrating a procedure of a method for manufacturing the magneto-optical recording medium 15 shown in FIG. I. Fig. 4 is a sectional view showing another example of the magneto-optical recording medium according to the present invention. 16 1224785 发明 Description of the invention [List of main symbols of the main elements of the drawing] 1 ... substrate 1 a ... upper surface of the substrate 1 b ... lower surface of the substrate 2 ... soft magnetic layer 3 ... recessed formation layer 4 ... optical magnetic recording layer 5 ... Protective layer 6 ... Die 7 ... Die 8 ... Transparent die 11,31 ... Concave rail 12, 32 ... convex projection 111 ... recessed bottom surface 112 ... recessed sidewall surface 121 ... convex flat surfaces D1, D2 ··· Optical Magnetic Disc 17