JP3038888B2 - Magnetic disk - Google Patents
Magnetic diskInfo
- Publication number
- JP3038888B2 JP3038888B2 JP02298724A JP29872490A JP3038888B2 JP 3038888 B2 JP3038888 B2 JP 3038888B2 JP 02298724 A JP02298724 A JP 02298724A JP 29872490 A JP29872490 A JP 29872490A JP 3038888 B2 JP3038888 B2 JP 3038888B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic disk
- disk
- frictional force
- magnetic head
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
- G11B5/739—Magnetic recording media substrates
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/712—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the surface treatment or coating of magnetic particles
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/90—Magnetic feature
Landscapes
- Magnetic Record Carriers (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、円板状の剛性基板に磁性層が形成されてな
る磁気ディスク（いわゆるハードディスク）に関するも
のである。Description: TECHNICAL FIELD The present invention relates to a magnetic disk (a so-called hard disk) in which a magnetic layer is formed on a disk-shaped rigid substrate.
〔発明の概要〕 本発明は、テクスチャ処理により表面粗さが規定され
てなる磁気ディスクにおいて、径方向における算術平均
中心線から最深谷底までの値Rvと最高山頂までの値Rpの
関係を最適化することで、CSS（コンタクト・スタート
・ストップ）耐久性の向上を図ろうとするものである。[Summary of the Invention] The present invention optimizes the relationship between the value Rv from the arithmetic mean center line in the radial direction to the deepest valley and the value Rp from the highest peak to the magnetic disk in which the surface roughness is defined by texture processing. By doing so, it is intended to improve CSS (contact start / stop) durability.
例えばコンピュータ等の記憶媒体としては、ランダム
アクセスが可能な円板状の磁気ディスクが広く用いられ
ており、なかでも基板にアルミニウム合金等を用いた，
いわゆるハードディスクが、応答性に優れ記憶容量が大
きい等の理由により、固定ディスクあるいは外部ディス
クとして用いられている。For example, as a storage medium for a computer or the like, a disk-shaped magnetic disk that can be randomly accessed is widely used.
A so-called hard disk is used as a fixed disk or an external disk because of its excellent responsiveness and large storage capacity.
ところで、上述の磁気ディスク（ハードディスク）に
おいては、走行性，耐久性等の観点から、磁気ヘッドと
の接触面が微細な凹凸によって適度な表面粗さを有する
ことが必要とされ、例えば円板状の剛性基板の表面を周
方向にラッピングし微細な傷を付けることで前記表面粗
さをコントロールする技術が、テクスチャ処理として知
られている。By the way, in the above-mentioned magnetic disk (hard disk), the contact surface with the magnetic head is required to have an appropriate surface roughness due to fine irregularities from the viewpoint of running property, durability and the like. The technique of controlling the surface roughness by lapping the surface of the rigid substrate in the circumferential direction and making fine scratches is known as texture processing.
この場合、磁気ディスクの表面粗さは、主に磁気ヘッ
ドの浮上量さCSS特性によって制約され、表面粗さが過
度に大きすぎると，いわゆるヘッドヒットの原因とな
り、逆に表面粗さが小さすぎると磁気ヘッドとの摩擦係
数が大きくなるという不都合が生ずる。In this case, the surface roughness of the magnetic disk is mainly limited by the flying height CSS characteristics of the magnetic head. If the surface roughness is too large, it causes a so-called head hit, and conversely, the surface roughness is too small The disadvantage is that the coefficient of friction between the magnetic head and the magnetic head increases.
したがって、これまでは磁気ディスク表面の表面粗さ
を中心線平均粗さRa等で評価し、これを最適化すること
で磁気ヘッドとの最大摩擦力を下げ、耐久性を高めた
り，いわゆるはりつきを解消することが検討されてい
る。（例えば特開昭62−46429号） 〔発明が解決しようとする課題〕 しかしながら、本発明者等が、磁気ヘッドにおける最
も重要な特性であるCSS耐久性について検討を重ねたと
ころ、前記中心線平均粗さ等を規定するだけでは不十分
であるとの結論を得るに至った。So far, the surface roughness of the magnetic disk surface has been evaluated using the center line average roughness Ra, etc., and by optimizing this, the maximum frictional force with the magnetic head can be reduced, the durability increased, and so-called sticking can be reduced. It is being considered to eliminate it. (For example, Japanese Patent Application Laid-Open No. 62-46429) [Problems to be Solved by the Invention] However, the present inventors have repeatedly studied the CSS durability which is the most important characteristic of the magnetic head, It was concluded that simply specifying the roughness etc. was not enough.
本発明は、このような検討結果に基づいて提案された
ものであって、磁気ヘッドに対する摩擦係数が小さいこ
とはもちろん、CSS耐久性にも優れた磁気ディスクを提
供することを目的とする。The present invention has been proposed based on the above-described study results, and it is an object of the present invention to provide a magnetic disk having not only a low friction coefficient with respect to a magnetic head but also excellent CSS durability.
本発明者等は、上述の目的を達成すべく鋭意検討を重
ね、磁気ディスクの表面の凹凸の状態によって、磁気ヘ
ッドと磁気ディスク表面間に摩擦力が働く時間に差が生
じることを見出した。そして、磁気ヘッドに加わるCSS
時の摩擦力の時間変化を詳細に検討したところ、磁気デ
ィスク表面の径方向における表面凹凸の算術平均中心線
から最深谷底までの値Rvと最高山頂までの値Rpが所定の
関係にあるときに摩擦力が働く時間が短くなり、最も良
いCSS特性が得られることがわかった。The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and have found that there is a difference in the time during which a frictional force acts between the magnetic head and the magnetic disk surface depending on the state of the unevenness on the surface of the magnetic disk. And CSS added to the magnetic head
When the time change of the frictional force at the time was examined in detail, when the value Rv from the arithmetic mean center line of the surface irregularities in the radial direction of the magnetic disk surface to the deepest valley and the value Rp from the highest peak to the top were in a predetermined relationship, It was found that the working time of frictional force was shortened and the best CSS characteristics were obtained.
本発明は、上述の知見に基づいて完成されたものであ
って、周方向にテクスチャ処理された円板の剛性基板上
に少なくとも磁性層が形成されてなる磁気ディスクにお
いて、該磁気ディスク表面の径方向における表面凹凸の
算術平均中心線から最深谷底までの値Rvと最高山頂まで
の値Rpとが、1.20≧Rp/Rv≧0.6なる関係を満足すること
を特徴とするものである。The present invention has been completed on the basis of the above-described findings, and is directed to a magnetic disk in which at least a magnetic layer is formed on a disk-shaped rigid substrate that has been textured in the circumferential direction. The value Rv from the arithmetic mean center line of the surface irregularities in the direction to the deepest valley and the value Rp from the highest peak to the highest peak satisfy the relationship of 1.20 ≧ Rp / Rv ≧ 0.6.
上記表面凹凸の算術平均中心線から最深谷底までの値
Rvと最高山頂までの値Rpは、第１図に示すように、測定
区間における表面凹凸の高さの算術平均を求め、これを
中心線Ｌとしたときに、中心線Ｌから測定区間内で最も
深い谷の谷底までの深さ及び中心線Ｌから測定区間内で
最も高い山の山頂までの高さとして測定されるものであ
る。そして、これらの値Rv,Rpは、磁気ディスク表面の
中心線平均粗さ等が同じであっても表面凹凸の振幅分布
によって大きく異なった値を示す。Values from the arithmetic mean center line of the above surface irregularities to the deepest valley bottom
As shown in FIG. 1, Rv and the value Rp to the highest peak are obtained by calculating the arithmetic mean of the heights of the surface irregularities in the measurement section, and using this as the center line L, within the measurement section from the center line L. It is measured as the depth to the bottom of the deepest valley and the height from the center line L to the peak of the highest mountain in the measurement section. These values Rv and Rp vary greatly depending on the amplitude distribution of the surface irregularities even if the center line average roughness of the magnetic disk surface is the same.
本発明では、剛性基板の表面状態をコントロールする
ことで、磁気ディスク表面の表面凹凸における前記Rv,R
pがRp/Rv≧0.6なる関係を満足するように設定する。な
お、ここで表面凹凸の状態が問題となるのは、実際に磁
気ヘッドと接触する磁気ディスク表面であって、したが
って例えば磁性層表面が直接磁気ヘッドと接触する場合
には磁性層の表面状態が、また磁性層表面にカーボン保
護膜が形成されている場合にはカーボン保護膜の表面状
態が前記関係を満足する必要がある。In the present invention, by controlling the surface state of the rigid substrate, the Rv, R
It is set so that p satisfies the relationship of Rp / Rv ≧ 0.6. Here, the state of the surface unevenness is a problem on the surface of the magnetic disk actually in contact with the magnetic head. Therefore, for example, when the surface of the magnetic layer directly contacts the magnetic head, the surface state of the magnetic layer is changed. When a carbon protective film is formed on the surface of the magnetic layer, the surface condition of the carbon protective film needs to satisfy the above relationship.
このとき、中心線平均粗さRaや最大高さRmaxの値は任
意であるが、あまり表面が荒れ過ぎると磁気ヘッドの走
行に支障を来たし電磁変換特性も低下することから、中
心線平均粗さRaは20nm以下、最大高さRmaxは200nm以下
とすることか好ましい。At this time, the values of the center line average roughness Ra and the maximum height R max are arbitrary, but if the surface is too rough, the running of the magnetic head is hindered and the electromagnetic conversion characteristics are deteriorated. It is preferable that Ra is 20 nm or less and the maximum height Rmax is 200 nm or less.
剛性基板の表面状態は、テクスチャ処理によってコン
トロールされるが、テクスチャ処理の手法としては、ラ
ッピングテープを基板の周方向にこすりつけ、基板の周
方向に微細な傷を付ける方法が好適である。ここで、ラ
ッピングテープの種類（例えば表面粗さ等）を変えた
り、異なる種類のラッピングテープによる処理を組み合
わせること等で、前記磁気ディスク表面の表面凹凸にお
けるRv,Rpの値をコントロールすることがでる。The surface state of the rigid substrate is controlled by texture processing. As a texture processing method, a method in which a lapping tape is rubbed in the circumferential direction of the substrate and fine scratches are formed in the circumferential direction of the substrate is preferable. Here, the values of Rv and Rp in the surface irregularities of the magnetic disk surface can be controlled by changing the type (for example, surface roughness) of the wrapping tape or by combining the processes with different types of wrapping tape. .
テクスチャ処理される基板は、剛性の基板であって、
アルミニウム基板、アルミニウム合金基板、Ni−Ｐメッ
キを施したアルミニウム基板，アルミニウム合金基板、
アルマイト処理を施したアルミニウム基板，アルミニウ
ム合金基板、ガラス基板、ポリエーテルイミド，ポリカ
ーボネート，ポリサルホン，ポリエーテルサルホン，ポ
リアセタール，ポリフェニレンサルファイド等の材料よ
りなるプラスチック基板等が使用可能である。The substrate to be textured is a rigid substrate,
Aluminum substrate, aluminum alloy substrate, aluminum substrate with Ni-P plating, aluminum alloy substrate,
An anodized aluminum substrate, an aluminum alloy substrate, a glass substrate, a plastic substrate made of a material such as polyetherimide, polycarbonate, polysulfone, polyethersulfone, polyacetal, and polyphenylene sulfide can be used.
一方、前記剛性基板上に形成される磁性層は、磁性粉
末，結合剤等を主体とする磁性塗料を塗布することによ
って形成される磁性塗膜であってもよいし、強磁性金属
材料（例えばCo−Ni合金やCo−Cr−Ta合金,Co−Cr−Ni
合金等）をメッキや蒸着，スパッタ等の薄膜形成技術に
より成膜することによって形成される金属薄膜であって
もよく、何ら制約されるものではない。また、磁性層と
して金属薄膜を形成する場合には、必要に応じて下地膜
を形成してもよい。この場合、下地膜の材質としては、
Bi,Cr等が挙げられ、膜厚は数十Å〜数千Å程度（例え
ばCr下地膜の場合、700〜1000Å程度）に設定すればよ
い。On the other hand, the magnetic layer formed on the rigid substrate may be a magnetic coating film formed by applying a magnetic paint mainly composed of a magnetic powder, a binder, or the like, or a ferromagnetic metal material (for example, Co-Ni alloy, Co-Cr-Ta alloy, Co-Cr-Ni
An alloy or the like may be a metal thin film formed by forming a film by a thin film forming technique such as plating, vapor deposition, or sputtering, and is not limited at all. When a metal thin film is formed as the magnetic layer, a base film may be formed as necessary. In this case, as the material of the underlayer,
Bi, Cr, etc. may be mentioned, and the film thickness may be set to about several tens to several thousand (for example, about 700 to 1,000 for a Cr underlayer).
さらに、前記磁性層の表面には、必要に応じてカーボ
ン保護膜や潤滑剤層等が形成されていてもよい。使用す
る潤滑剤の種類は任意であるが、特にパーフルオロポリ
エーテル系の潤滑剤が好適である。また、カーボン保護
膜の膜厚は200〜500Åの範囲であることが好ましく、潤
滑剤層の膜厚は20〜60Åの範囲であることが好ましい。Further, a carbon protective film, a lubricant layer, and the like may be formed on the surface of the magnetic layer as needed. The type of the lubricant used is arbitrary, but a perfluoropolyether-based lubricant is particularly preferred. The thickness of the carbon protective film is preferably in the range of 200 to 500 °, and the thickness of the lubricant layer is preferably in the range of 20 to 60 °.
磁気ヘッドを接触させた状態で磁気ディスクの回転数
を第２図（Ａ）に示すように次第に上げていくと、CSS
開始時に磁気ヘッドと磁気ディスク表面の間に働く摩擦
力は、第２図（Ｂ）に示すようなものとなる。そして、
このとき磁気ディスクあるいは磁気ヘッドに加わるダメ
ージの大きさは、摩擦力の積分値で与えられる。When the rotation speed of the magnetic disk is gradually increased as shown in FIG. 2A with the magnetic head in contact, the CSS
At the start, the frictional force acting between the magnetic head and the surface of the magnetic disk is as shown in FIG. 2 (B). And
At this time, the magnitude of damage applied to the magnetic disk or the magnetic head is given by the integral value of the frictional force.
ここで、前記摩擦力のカーブは、磁気ディスク表面の
表面凹凸におけるRv,Rpの値によって変化し、Rp/Rvの値
が小さいと、磁気ヘッドに加わる最大摩擦力Fmはさほど
変わらないが、摩擦力が磁気ヘッドの浮上とともに零に
なるまでの時間tmが長くなる傾向にある。このことは、
Rp/Rvの値が小さくなると、磁気ヘッドに働く摩擦力は
尾を引き、磁気ヘッドが磁気ディスク表面を引きずる時
間が長くなることを示している。Here, the curve of the frictional force varies Rv, the value of Rp in the surface roughness of the magnetic disk surface, the value of Rp / Rv is small, the maximum frictional force F m applied to the magnetic head but does not change much, The time t m until the frictional force becomes zero as the magnetic head floats tends to increase. This means
As the value of Rp / Rv decreases, the frictional force acting on the magnetic head trails, indicating that the time for the magnetic head to drag the surface of the magnetic disk increases.
したがって、例えば最大摩擦力を下げるために表面粗
さを粗くした場合、通常はRvの値が大きくなってRp/Rv
の値が小さくなり、摩擦力が零になるまでの時間tmが長
くなって積分値が大きくなり、結果としてCSS耐久性が
悪くなることになる。Therefore, for example, when the surface roughness is roughened to reduce the maximum frictional force, usually the value of Rv becomes large and Rp / Rv
Becomes small, the time t m until the frictional force becomes zero becomes long, and the integral value becomes large, resulting in poor CSS durability.
これに対して、本発明においては、Rp/Rvの値を0.6以
上としているので、摩擦力が零になるまでの時間tmが短
いものとなり、CSS耐久性が確保される。On the other hand, in the present invention, since the value of Rp / Rv is set to 0.6 or more, the time t m until the frictional force becomes zero is short, and CSS durability is secured.
以下、本発明を具体的な実験結果に基づいて説明す
る。Hereinafter, the present invention will be described based on specific experimental results.
実験例１ 本実験例において使用したサンプルディスクは、Ni−
Ｐメッキが施されたテクスチャ処理により表面凹凸状態
を変えたアルミニウム基板上に磁性層、カーボン保護膜
及び潤滑剤層を順次成膜してなるものである。磁性層
は、Co−Ni合金（Co90原子％、Ni10原子％）のスパッタ
膜であり、膜厚500Åである。また、磁性層の下地膜と
して、膜厚100Åのビスマス下地膜を形成した。一方、
カーボン保護膜の膜厚は350〜400Å、潤滑剤層の膜厚は
40Åとした。使用した潤滑剤は、パーフルオロポリエー
テル（商品名：フォンブリン）である。Experimental Example 1 The sample disk used in this experimental example was Ni-
A magnetic layer, a carbon protective film, and a lubricant layer are sequentially formed on an aluminum substrate whose surface unevenness has been changed by texture processing on which P plating has been applied. The magnetic layer is a sputtered film of a Co-Ni alloy (90 atomic% of Co, 10 atomic% of Ni) and has a thickness of 500 Å. In addition, a bismuth base film having a thickness of 100 mm was formed as a base film of the magnetic layer. on the other hand,
The thickness of the carbon protective film is 350 to 400 mm, and the thickness of the lubricant layer is
40 mm. The lubricant used was perfluoropolyether (trade name: Fomblin).
各サンプルディスクのRp,Rv,Rp/Rv,並びに磁気ヘッド
に加わる最大摩擦力Fm,摩擦力が磁気ヘッドの浮上によ
って零になるまでの時間tmを表１−１及び表１−２に示
す。ここで、表１−１に示すサンプルディスクが本発明
の実施例に相当し、表１−２に示すサンプルディスクは
比較例に相当する。Tables 1-1 and 1-2 show Rp, Rv, Rp / Rv of each sample disk, the maximum frictional force F m applied to the magnetic head, and the time t m until the frictional force becomes zero due to the floating of the magnetic head. Show. Here, the sample disks shown in Table 1-1 correspond to Examples of the present invention, and the sample disks shown in Table 1-2 correspond to Comparative Examples.
なお、各サンプルディスクにおけるRp,Rv,Rp/Rvの各
値は、磁性層及びカーボン保護膜を形成した状態で測定
し、測定長は0.6mmとした。The values of Rp, Rv, and Rp / Rv in each sample disk were measured with the magnetic layer and the carbon protective film formed, and the measurement length was 0.6 mm.
また、最大摩擦力Fmや時間tmの測定に際しては、磁気
ディスク回転数を3600rpm、前記回転数まで立ち上がる
までの時間〔第２図（Ａ）中のＴ〕を４秒とした。In measuring the maximum frictional force F m and the time t m , the rotation speed of the magnetic disk was set to 3600 rpm, and the time required for the magnetic disk to rise to the rotation speed [T in FIG. 2 (A)] was set to 4 seconds.
これらの表を見ても明らかな通り、磁気ディスクの表
面状態をコントロールしRp/Rvの値を0.6以上としたとき
に、特に摩擦力が零になるまでの時間tmが短くなり、積
分された摩擦力が小さくなることがわかる。 As is clear from these tables, when the surface condition of the magnetic disk is controlled and the value of Rp / Rv is set to 0.6 or more, the time t m until the frictional force becomes zero becomes short, and the integral is reduced. It can be seen that the frictional force is reduced.
実験例２ 磁性層をCo−Cr−Ta合金とし、Crを下地膜として先の
実験例１と同様にサンプルディスクを作成した。Co−Cr
−Ta合金の膜厚は500Å、Cr下地膜の膜厚は700Åであ
る。なお、磁性層として好適なCo−Cr−Ta合金の組成範
囲は、CoxCryTaz（x,y,zはいずれも重量％）としたとき
に、 ４≦ｙ≦20 ０＜ｚ≦５ ｘ＝残部 であるが、ここではCo86Cr12Ta2とした。Experimental Example 2 A sample disk was prepared in the same manner as in Experimental Example 1 except that the magnetic layer was made of a Co—Cr—Ta alloy and Cr was used as a base film. Co-Cr
The thickness of the -Ta alloy is 500 mm, and the thickness of the Cr underlayer is 700 mm. The composition range of suitable Co-Cr-Ta alloy as the magnetic layer, Co x Cr y Ta z when (x, y, z are all% by weight), which was, 4 ≦ y ≦ 20 0 < z ≦ 5 x = remainder, but here, Co 86 Cr 12 Ta 2 was used.
これらサンプルディスクについても、Rp,Rv,Rp/Rv,並
びに磁気ヘッドに加わる最大摩擦力Fm,摩擦力が磁気ヘ
ッドの浮上によって零になるまでの時間tmを測定した。
結果を表２−１及び表２−２に示す。ここでも、表２−
１に示すサンプルディスクが本発明の実施例に相当し、
表２−２に示すサンプルディスクは比較例に相当する。For even these sample disks were measured Rp, Rv, Rp / Rv, and the maximum frictional force applied to the magnetic head F m, the time t m to the frictional force becomes zero by flying of the magnetic head.
The results are shown in Tables 2-1 and 2-2. Again, Table 2-
The sample disk shown in FIG. 1 corresponds to an embodiment of the present invention,
The sample disks shown in Table 2-2 correspond to comparative examples.
磁性層をCo−Cr−Ta合金（Co86Cr12Ta2）とした場合
にも、Rp/Rvの値を0.6以上とすることで、やはり積分さ
れた摩擦力が小さくなることがわかる。 Even when the magnetic layer is made of a Co—Cr—Ta alloy (Co 86 Cr 12 Ta 2 ), it can be seen that the integrated frictional force is also reduced by setting the value of Rp / Rv to 0.6 or more.
さらに、磁性層をCo84Cr12Ta4として同様の実験を行
ったところ、Co86Cr12Ta2の場合と同様の結果が得られ
た。Further, when a similar experiment was performed using Co 84 Cr 12 Ta 4 as the magnetic layer, the same result as in the case of Co 86 Cr 12 Ta 2 was obtained.
以上の説明からも明らかなように、本発明において
は、磁気ディスクの表面凹凸におけるRp/Rvの値を0.6以
上となるように設定しているので、磁気ヘッドや磁気デ
ィスクに加わるダメージ（特に摩擦力の積分値）を小さ
くすることができ、CSS耐久性を向上することが可能で
ある。As is clear from the above description, in the present invention, since the value of Rp / Rv in the surface irregularities of the magnetic disk is set to be 0.6 or more, damage (particularly friction) applied to the magnetic head and the magnetic disk (Integral value of force) can be reduced, and CSS durability can be improved.
第１図はRp及びRvを説明するための模式図である。 第２図（Ａ）はCSS開始時の磁気ディスクの回転数の変
化を示す特性図であり、第２図（Ｂ）はそのときの摩擦
力の変化を示す特性図である。FIG. 1 is a schematic diagram for explaining Rp and Rv. FIG. 2A is a characteristic diagram showing a change in the number of rotations of the magnetic disk at the start of CSS, and FIG. 2B is a characteristic diagram showing a change in the frictional force at that time.
フロントページの続き (56)参考文献 特開 昭64−23419（ＪＰ，Ａ) 特開 昭61−243937（ＪＰ，Ａ) 特開 昭62−46429（ＪＰ，Ａ) 特開 平１−208724（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G11B 5/82 Continuation of front page (56) References JP-A-64-23419 (JP, A) JP-A-61-243937 (JP, A) JP-A-62-46429 (JP, A) JP-A-1-208724 (JP) , A) (58) Field surveyed (Int. Cl. 7 , DB name) G11B 5/82
Claims (1)
性基板上に少なくとも磁性層が形成されてなる磁気ディ
スクにおいて、 該磁気ディスク表面の径方向における表面凹凸の算術平
均中心線から最深谷底までの値Rvと最高山頂までの値Rp
とが、 1.20≧Rp/Rv≧0.6 なる関係を満足することを特徴とする磁気ディスク。1. A magnetic disk in which at least a magnetic layer is formed on a disk-shaped rigid substrate textured in the circumferential direction, wherein a deepest valley is formed from an arithmetic mean center line of surface irregularities in a radial direction of the magnetic disk surface. Up to Rv and up to the peak Rp
Satisfies the following relationship: 1.20 ≧ Rp / Rv ≧ 0.6.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE69103778T DE69103778T2 (en) | 1990-01-19 | 1991-01-18 | Magnetic recording disk. |
| KR1019910000819A KR910014880A (en) | 1990-01-19 | 1991-01-18 | Magnetic recording disc |
| EP91100601A EP0438177B1 (en) | 1990-01-19 | 1991-01-18 | Magnetic recording disk |
| US07/644,222 US5144512A (en) | 1990-01-19 | 1991-01-22 | Magnetic recording disk having textured surface |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP850890 | 1990-01-19 | ||
| JP2-8508 | 1990-01-19 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03250424A JPH03250424A (en) | 1991-11-08 |
| JP3038888B2 true JP3038888B2 (en) | 2000-05-08 |
Family
ID=11695068
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP02298724A Expired - Fee Related JP3038888B2 (en) | 1990-01-19 | 1990-11-02 | Magnetic disk |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP3038888B2 (en) |
| KR (1) | KR910014880A (en) |
-
1990
- 1990-11-02 JP JP02298724A patent/JP3038888B2/en not_active Expired - Fee Related
-
1991
- 1991-01-18 KR KR1019910000819A patent/KR910014880A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03250424A (en) | 1991-11-08 |
| KR910014880A (en) | 1991-08-31 |
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