JPH08293117A - Production of magnetic recording medium - Google Patents
Production of magnetic recording mediumInfo
- Publication number
- JPH08293117A JPH08293117A JP7096993A JP9699395A JPH08293117A JP H08293117 A JPH08293117 A JP H08293117A JP 7096993 A JP7096993 A JP 7096993A JP 9699395 A JP9699395 A JP 9699395A JP H08293117 A JPH08293117 A JP H08293117A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic recording
- substrate
- recording medium
- underlayer
- laser
- 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.)
- Granted
Links
Landscapes
- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、磁気記録媒体の製造方
法に関し、詳しくは磁気ディスク装置に使用されるハー
ドディスク、磁気テープなどの磁気記録媒体の製造方法
に関するものである。特に、磁気ディスク装置において
は、良好なCSS(コンタクトスタートアンドストッ
プ)特性およびヘッドの媒体表面へのスティッキング特
性とヘッドの低浮上化を同時に可能にする薄膜型の磁気
記録媒体の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic recording medium, and more particularly to a method for manufacturing a magnetic recording medium such as a hard disk or a magnetic tape used in a magnetic disk device. In particular, the present invention relates to a method for manufacturing a thin-film magnetic recording medium that enables good CSS (contact start and stop) characteristics, sticking characteristics of the head to the medium surface, and low flying height of the head at the same time in a magnetic disk device.
【0002】[0002]
【従来の技術】通常、ハードディスクはその使用に際
し、ディスクを高速で回転して磁気ヘッドを浮上させ、
ハードディスクへの書き込み/読み出し等をこの磁気ヘ
ッドを介して行っている。ハードディスクは、その磁気
特性の向上のため、ディスクの基板面あるいは基板面上
に設けられたNiPメッキ等の非磁性体からなる下地層
上に、磁気ディスクの円周方向にほぼ同心円状に機械的
研磨を行って加工痕を残す加工(以下、機械的テキスチ
ャという)が行われている。また、表面性と硬度に優れ
るガラス基板を使う場合には、弗酸でガラスの表面をエ
ッチングして表面に凹凸を付ける方法や微小な粒子を基
板の表面に塗布する方法が用いられている。2. Description of the Related Art Normally, when using a hard disk, the hard disk is rotated at a high speed to float a magnetic head,
Writing / reading to / from a hard disk is performed via this magnetic head. In order to improve the magnetic characteristics of a hard disk, a hard disk is mechanically concentrically formed in the circumferential direction of the magnetic disk on the base surface of the disk or on a base layer made of a non-magnetic material such as NiP plating provided on the base surface. Processing (hereinafter, referred to as mechanical texture) is performed by polishing to leave processing marks. Further, when a glass substrate having excellent surface properties and hardness is used, a method of etching the surface of the glass with hydrofluoric acid to make the surface uneven and a method of applying fine particles to the surface of the substrate are used.
【0003】近年の情報量の増大と装置の小型軽量化の
要求により、線記録密度及びトラック密度が高くなり、
1ビット当りの面積が小さくなってくると、従来のよう
な機械的テキスチャによるスクラッチ傷は情報読み出し
の際にエラーとなる確率が高くなる。また、内周部にあ
るCSSゾーンのみに機械的テキスチャを施しデータ記
録領域はそのままにする方法もあるが、データ記録領域
の面がCSSゾーンの面の高さよりも高くなり、ヘッド
がシークする時にクラッシュするという問題があった。Due to the recent increase in the amount of information and the demand for smaller and lighter devices, the linear recording density and track density have increased,
As the area per bit becomes smaller, scratches due to mechanical texture as in the conventional case have a higher probability of becoming an error in reading information. There is also a method of mechanically texturing only the CSS zone on the inner periphery and leaving the data recording area as it is, but when the surface of the data recording area is higher than the height of the surface of the CSS zone and the head seeks. There was a problem of crashing.
【0004】また、こうした機械的テキスチャに代え
て、レーザでテキスチャパターンを作る方法も提案され
ている。レーザによるテキスチャの方法の例は、米国特
許第5,062,021号、同5,108,781号に
開示されており、Nd−YAGの強パルスレーザ光によ
りNiP層を局所的に溶融し、溶融して形成された凹状
の穴部とその周囲に溶融したNiPが表面張力で盛り上
がって固化した直径が2.5〜100μmのリム部から
なるクレータ状の凹凸を多数作り、円環状の凸状リムに
よってヘッドとのCSS特性を改善する試みが提案され
ている。しかし、これらの特許に記載の方法は、レーザ
ビームの照射範囲が広く、かつレーザの出力も大出力で
あるため、NiPの溶融範囲が広くなり、溶融した液面
の中心部が盛り上がらずにクレータ状となってしまうの
が特徴であり、この場合、凸部分先端とヘッド下面との
接触面積が飛躍的には下がらず、ヘッドとディスク間の
スティッキングの問題は、機械的テキスチャに較べて改
善されているとは言い難い。Also, a method of making a texture pattern by a laser has been proposed in place of such a mechanical texture. An example of a laser texture method is disclosed in US Pat. Nos. 5,062,021 and 5,108,781, in which a NiP layer is locally melted by a strong pulsed laser beam of Nd-YAG, A large number of crater-like concavities and convexities formed by melting and forming a concave hole portion and the molten NiP around the periphery of the hole and solidifying by swelling due to surface tension, forming a crater-like convex portion. Attempts have been proposed to improve CSS characteristics with the head by the rim. However, in the methods described in these patents, since the irradiation range of the laser beam is wide and the output of the laser is also large, the melting range of NiP is wide, and the central part of the melted liquid surface does not rise and the crater does not rise. In this case, the contact area between the tip of the convex part and the bottom surface of the head does not decrease dramatically, and the problem of sticking between the head and the disk is improved compared to mechanical texture. It is hard to say that
【0005】また、先に本発明者らは特願平6−152
131号において、パルスレーザで作成した凸状突起を
テキスチャパターンとして利用する方法を提案した。こ
の方法はCSS特性改善に極めて有効であるが、この場
合でも凸状突起の頂部の曲率が小さいと、高温、高湿等
の環境ではCSS特性が劣化するという問題が生じるこ
とがある。In addition, the present inventors previously filed Japanese Patent Application No. 6-152.
In No. 131, a method of using a convex protrusion formed by a pulse laser as a texture pattern was proposed. This method is extremely effective in improving the CSS characteristics, but even in this case, if the curvature of the tops of the convex protrusions is small, the CSS characteristics may deteriorate in an environment such as high temperature and high humidity.
【0006】また、突起をフォトリソグラフィを使って
形成する方法も提案されており、日本潤滑学会トライボ
ロジー予稿集(1991−5,A−11),(1992
−10,B−6)にはディスクの全表面に対する面積比
が0.1〜5%の同心円状の凸部、または突起をフォト
リソグラフィによって形成した磁気ディスクのCSSの
テスト結果が開示されている。しかし、この方法では、
突起の頂部が平滑なため、ヘッドの摺動回数と共に摩擦
が増加するという欠点があり、また工業化も容易でない
という問題があった。A method of forming protrusions using photolithography has also been proposed, and the tribology preliminary papers of the Japan Lubricating Society (1991-5, A-11), (1992).
-10, B-6) discloses the CSS test results of a magnetic disk in which concentric convex portions or projections having an area ratio of 0.1 to 5% to the entire surface of the disk are formed by photolithography. . But with this method,
Since the tops of the projections are smooth, there is a drawback that friction increases with the number of times the head slides, and there is a problem that industrialization is not easy.
【0007】[0007]
【発明が解決しようとする課題】磁気記録媒体の高密度
化、媒体の表面性の向上に伴い、ヘッドと媒体の摺動特
性の改善を工業的に有利な方法で行うことが望まれてい
る。With the increase in density of magnetic recording media and the improvement of surface properties of media, it is desired to improve the sliding characteristics between the head and the media by an industrially advantageous method. .
【0008】[0008]
【課題を解決するための手段】本発明は、こうした高密
度磁気記録用の媒体の製造方法に対してなされたもので
あり、その要旨は、磁気記録媒体の基板または下地層の
表面に、エネルギー線を照射して基板または下地層の表
面に突起を形成した後、基板または下地層の表面に機械
的なテキスチャを施し、その後、必要とする下地層、磁
気記録層または保護層を製膜することを特徴とする磁気
記録媒体の製造方法、に存する。The present invention has been made to a method of manufacturing such a medium for high density magnetic recording, and its gist is to provide an energy-saving method on the surface of a substrate or an underlayer of the magnetic recording medium. After irradiating a line to form protrusions on the surface of the substrate or the underlayer, mechanically texture the surface of the substrate or the underlayer, and then form the required underlayer, magnetic recording layer or protective layer. And a method of manufacturing a magnetic recording medium characterized by the above.
【0009】以下、本発明を詳細に説明する。本発明に
おいては、まず、磁気記録媒体の基板または下地層の表
面に、エネルギー線を照射して基板または下地層の表面
に突起を形成する。ついで、突起が形成された基板また
は下地層の表面に機械的なテキスチャを施す。磁気記録
媒体を製造するためには、通常、非磁性基板上に膜厚が
通常20〜200nmのCr、あるいはCu等の下地層
を設ける。場合によっては基板と上記層との間に更に膜
厚が通常100〜20,000nmのNiPからなる下
地層を設けてもよい。The present invention will be described in detail below. In the present invention, first, the surface of the substrate or the underlayer of the magnetic recording medium is irradiated with energy rays to form protrusions on the surface of the substrate or the underlayer. Then, a mechanical texture is applied to the surface of the substrate or the underlayer on which the protrusion is formed. In order to manufacture a magnetic recording medium, an underlayer such as Cr or Cu having a film thickness of 20 to 200 nm is usually provided on a nonmagnetic substrate. In some cases, a base layer made of NiP and having a thickness of 100 to 20,000 nm may be further provided between the substrate and the above layer.
【0010】磁気記録媒体の基板または下地層の表面
に、エネルギー線を照射して基板または下地層の表面に
突起を形成する好ましい方法としては、磁気記録媒体用
基板またはこの上に下地層を設けた基板を回転させなが
ら、その表面に円周方向に沿って、出力を精度良く制御
したエネルギー線を照射して表面に突起を形成する。レ
ーザ光としては、Ar等のガスレーザ又は単一モードで
連続発振が可能なYAG等の固体レーザを変調器で適当
なパルス長にしたもの、あるいは、YAG、YLF等の
固体Qスイッチレーザ、あるいは半導体レーザ等が使わ
れる。パルス幅としては100ns以上が好ましい。ま
た、通常、波長が長い方が保護層に対する光透過率は高
いため、長波長側のレーザが好ましい。As a preferred method of irradiating the surface of the substrate or the underlayer of the magnetic recording medium with energy rays to form protrusions on the surface of the substrate or the underlayer, a substrate for the magnetic recording medium or an underlayer is provided on the substrate. While the substrate is rotated, the surface thereof is irradiated with an energy ray whose output is accurately controlled along the circumferential direction to form protrusions on the surface. As the laser light, a gas laser such as Ar or a solid-state laser such as YAG capable of continuous oscillation in a single mode with an appropriate pulse length by a modulator, a solid-state Q-switch laser such as YAG or YLF, or a semiconductor A laser or the like is used. The pulse width is preferably 100 ns or more. In addition, since the longer the wavelength is, the higher the light transmittance to the protective layer is, the laser on the long wavelength side is preferable.
【0011】本発明において、エネルギー線の照射によ
り形成された溶融液体部中で、エネルギー線の走査方向
と直角の方向には殆んど温度勾配がつかず、走査方向の
みに温度勾配が発生するような状態をつくると、液体表
面は温度が低い方が表面張力が高いため、溶融液体部の
うち温度の低い部分で丸く凸部となり、最後に固化する
高温部分、つまりビームが走査された最後の部分は凹部
となり、急冷固化されることにより、後述するような好
ましい形状の突起を形成することができる。In the present invention, in the molten liquid portion formed by the irradiation of energy rays, there is almost no temperature gradient in the direction perpendicular to the scanning direction of the energy rays, and a temperature gradient occurs only in the scanning direction. In such a state, the liquid surface has a higher surface tension when the temperature is lower, so that the molten liquid part becomes a round convex part at the low temperature part, and finally the high temperature part that solidifies, that is, the last part when the beam is scanned. The portion becomes a concave portion, and by being rapidly cooled and solidified, a protrusion having a preferable shape as described later can be formed.
【0012】こうした条件を達成するためには、エネル
ギー線の照射による磁気記録媒体の基板または下地層の
表面の溶融範囲を5μm以下の範囲とするのが好まし
い。特には、エネルギビーム走査方向と直角な方向にお
ける溶融範囲を5μm以下、好ましくは2.5μm以
下、更に好ましくは2μm以下とするのが好ましい。溶
融範囲が5μmを超えると、溶融部分の中心部分は凸状
とはならずに逆に凹状にへこみ、液体になった部分の周
囲の部分が凸状に盛り上がる。これは、溶融範囲が広い
と冷却時に溶融液体中に温度勾配が生じるためと思われ
る。通常、表面張力は温度が低い部分で大きいために周
囲から冷却された外周部分の表面張力が大きくなり、盛
り上がるものと思われる。In order to achieve such conditions, it is preferable to set the melting range of the surface of the substrate or the underlayer of the magnetic recording medium by the irradiation of energy rays to a range of 5 μm or less. Particularly, it is preferable that the melting range in the direction perpendicular to the energy beam scanning direction is 5 μm or less, preferably 2.5 μm or less, more preferably 2 μm or less. When the melting range exceeds 5 μm, the central portion of the melted portion does not have a convex shape but is recessed into a concave shape, and the peripheral portion of the liquid portion rises in a convex shape. This is probably because a wide melting range causes a temperature gradient in the molten liquid during cooling. Usually, since the surface tension is large in the low temperature part, the surface tension of the outer peripheral part cooled from the surrounding area is large, and it is considered that the surface tension rises.
【0013】好ましくは、照射するエネルギー線が、連
続状またはパルス状のレーザビーム、特にはパルス状の
レーザビームであり、被照射表面において、1回当りの
照射時間におけるパルス状レーザの走査距離がパルス状
レーザのスポット径の通常1/4以上、好ましくは1/
2以上とする。Preferably, the energy beam to be irradiated is a continuous or pulsed laser beam, particularly a pulsed laser beam, and the scanning distance of the pulsed laser in the irradiation time per irradiation is on the surface to be irradiated. Usually 1/4 or more of the spot diameter of the pulsed laser, preferably 1 /
2 or more.
【0014】本発明において、エネルギー線の走査方向
とは、静止した被照射媒体上でエネルギー線が走査する
方向のみならず、エネルギー線は静止させておき、被照
射媒体を回転させた状態で照射する場合の被照射媒体の
回転方向、あるいはエネルギー線及び被照射媒体を移動
させた場合等をも示す相対的なものである。また、本発
明においてエネルギー線のスポット径とはエネルギーの
84%が集中する1/e2 の径をいう。In the present invention, the scanning direction of the energy beam is not limited to the direction in which the energy beam scans on the stationary irradiation target medium, but the energy beam is kept stationary and the irradiation target medium is rotated. This is a relative one that also indicates the rotation direction of the irradiation target medium in the case of, or the case where the energy beam and the irradiation target medium are moved. Further, in the present invention, the spot diameter of the energy ray means a diameter of 1 / e 2 where 84% of energy is concentrated.
【0015】突起高さはレーザの強度とその平均照射時
間、及びディスクの線速度を調節することによって自由
に制御され、突起の密度は、1周当たりの突起の個数、
パルスレーザの半径方向の照射間隔、及び上記の突起の
高さを制御する条件を調節することにより自由に制御さ
れる。また、半径方向については連続的に移動させ、渦
巻状の走査を行なうようにすると時間的に効率がよい。
通常、レーザの強度は20〜500mW、平均照射時間
は0.05〜5μsec、レーザのスポット径は0.2
〜4μm、基板の線速度は1〜15m/secが好まし
い。ここで、レーザの平均照射時間とは、1つの突起を
形成させるのにレーザを下地層表面に照射した時間を示
す。The height of the protrusions can be freely controlled by adjusting the intensity of the laser, the average irradiation time thereof, and the linear velocity of the disk. The protrusion density is defined as the number of protrusions per revolution,
It can be freely controlled by adjusting the irradiation interval of the pulsed laser in the radial direction and the conditions for controlling the height of the protrusions. Further, it is efficient in terms of time if the spiral scanning is performed by continuously moving in the radial direction.
Usually, the laser intensity is 20 to 500 mW, the average irradiation time is 0.05 to 5 μsec, and the laser spot diameter is 0.2.
˜4 μm, and the linear velocity of the substrate is preferably 1 to 15 m / sec. Here, the average irradiation time of the laser refers to the time during which the surface of the underlayer is irradiated with the laser to form one protrusion.
【0016】レーザビームの照射面積を変えるには、通
常、用いるレーザの波長と対物レンズの開口率を変えれ
ばよく、開口率が0.1〜0.95の対物レンズを用い
ることにより、ビームの照射径は0.3〜6μm程度ま
で制御できる。本発明に用いるビームの照射径は2μm
以下、更に望ましくは1μm以下が望ましい。レーザの
システムとしては連続発振ができるAr等のガスレーザ
に変調器を用いたものや、固体レーザのYAG、あるい
は半導体レーザ等が利用できるが、いずれにしてもスポ
ット径が小さくできるシステムが望ましい。To change the irradiation area of the laser beam, it is usually necessary to change the wavelength of the laser used and the aperture ratio of the objective lens. By using an objective lens having an aperture ratio of 0.1 to 0.95, The irradiation diameter can be controlled to about 0.3 to 6 μm. The irradiation diameter of the beam used in the present invention is 2 μm.
Hereafter, it is more desirable to be 1 μm or less. As a laser system, a gas laser such as Ar capable of continuous oscillation using a modulator, a solid-state laser YAG, a semiconductor laser, or the like can be used. In any case, a system capable of reducing the spot diameter is desirable.
【0017】本発明の好ましい態様として、ハードディ
スク等においては、突起は磁気ヘッドがCSS(コンタ
クトスタートアンドストップ)を行なう領域に存在し、
データ記録領域には存在しないかあるいは低い密度で存
在する磁気記録媒体の作成方法が挙げられる。このよう
にすることにより、データ記録領域においては磁性層表
面を平滑にすることができるため、従来のようなスクラ
ッチ傷によるエラーを減少させることができる。As a preferred embodiment of the present invention, in a hard disk or the like, the protrusion is present in an area where the magnetic head performs CSS (contact start and stop),
A method of producing a magnetic recording medium that does not exist in the data recording area or exists at a low density can be mentioned. By doing so, the surface of the magnetic layer can be made smooth in the data recording area, so that errors due to scratches as in the conventional case can be reduced.
【0018】また、さらに好ましい態様として、突起を
磁気ヘッドがCSSを行なう領域に作成しデータ記録領
域には作成せず、あるいは低い密度で作成し、かつその
突起の高さをデータ記録領域に向かって減少するように
磁気記録媒体を作成することが挙げられる。突起高さを
データ記録領域に向かって減少させることにより、デー
タ記録領域からCSSゾーンあるいは逆の方向にヘッド
を安定にシークすることができる。また、突起の密度を
データ記録領域に向かって減少させることにより突起高
さを低減させた場合と同様な効果を得ることができる。
また、該突起の高さおよび密度の両方をデータ記録領域
に向かって減少させることも好ましい。また、テープ等
に対しては、テープ両端の摺動特性が走行に影響を与え
るので、テープの両端部分に本発明による突起を作成す
ると、より効果的である。In a further preferred embodiment, the protrusions are formed in the area where the magnetic head performs CSS and not in the data recording area, or are formed at a low density, and the height of the protrusion is directed toward the data recording area. The magnetic recording medium can be manufactured so that the number of magnetic recording media decreases. By decreasing the protrusion height toward the data recording area, the head can be stably sought from the data recording area to the CSS zone or the opposite direction. Further, by reducing the density of the protrusions toward the data recording area, the same effect as when the height of the protrusions is reduced can be obtained.
It is also preferable to reduce both the height and density of the protrusions toward the data recording area. Further, with respect to a tape or the like, the sliding characteristics at both ends of the tape affect the running, so that it is more effective to form the protrusions according to the present invention at both end portions of the tape.
【0019】突起高さをデータ記録領域に向かって減少
させるためには、エネルギー線の出力をデータ記録領域
に向かって減少させる等の方法が挙げられる。また、突
起密度をデータ記録領域に向かって減少させるために
は、エネルギー線の照射間隔をデータ記録領域に向かっ
て大きくする等の方法が挙げられる。In order to reduce the height of the protrusion toward the data recording area, there is a method of reducing the output of energy rays toward the data recording area. Further, in order to decrease the protrusion density toward the data recording area, there is a method of increasing the irradiation interval of energy rays toward the data recording area.
【0020】本発明において、エネルギー線被照射媒体
表面に作成される突起の高さは、JIS表面粗さ(B0
601−1982)により規定される、粗さ曲線の中心
線を基準とした場合の突起の高さを表す。この突起の高
さは、好ましくは1〜60nm、特に好ましくは10〜
60nmであり、60nmを超えるとハードディスク等
ではCSS特性は良いがヘッドの安定浮上高さは下げら
れず、また、テープ等では媒体と磁気ヘッドのスペーシ
ングが大きくなって出力が低下する。また、1nm未満
では基板が元来有する細かな粗さに埋もれてしまい所望
の効果は得られない。In the present invention, the height of the protrusions formed on the surface of the medium to be irradiated with energy rays is defined by JIS surface roughness (B0
601-1982), the height of the protrusion with respect to the center line of the roughness curve. The height of the protrusion is preferably 1 to 60 nm, particularly preferably 10 to
The thickness is 60 nm, and if it exceeds 60 nm, the CSS characteristics are good in a hard disk or the like, but the stable flying height of the head cannot be lowered, and in a tape or the like, the spacing between the medium and the magnetic head is large and the output is reduced. On the other hand, if the thickness is less than 1 nm, the substrate is buried in the original fine roughness, and the desired effect cannot be obtained.
【0021】また、前述の突起高さを有する突起は、1
mm2 あたり10〜108 個存在するのが好ましい。1
0個未満では基板のうねり等によりヘッド下面を突起の
みで支えるのは難しくなり、また108 個を超えて突起
を作ろうとすると互いに干渉しあって突起の高さをそろ
えるのが難しくなり、特に好ましい存在密度は1mm 2
あたり103 〜106 個である。ここで突起の存在密度
は媒体全体での平均密度ではなく、突起存在部での単位
面積当たりの密度をいう。また、該突起は、その頂点か
ら1nm下の高さにおける等高線で囲まれた図形の面積
の平均値(以下、等高線面積という)が2μm2 以下で
あるのが好ましく、さらには、1.0μm2 以下、更に
好ましくは0.5μm2 以下、特に好ましくは0.2μ
m2 以下の範囲の値を有する。2μm2 を超えるとヘッ
ドとの間にスティッキングが発生しやすくなる。なお、
この等高線面積は、レーザ干渉による表面形状測定装
置、例えば、米国ザイゴ社製ザイゴ(ZYGO)で測定
が可能である。The protrusion having the above-mentioned protrusion height is 1
mm2Per 10-108It is preferable that there is one. 1
If the number is less than 0, the head bottom surface may be
It ’s difficult to support it by yourself, and it ’s 108Protrusion beyond the individual
When you try to make the
It becomes difficult to obtain, especially preferable existence density is 1 mm 2
Per 103-106It is an individual. Where the density of protrusions is
Is not the average density of the entire medium, but the unit at the protrusion
It is the density per area. Also, is the protrusion
Area of the figure surrounded by contour lines at a height of 1 nm below
Average value (hereinafter referred to as contour area) is 2 μm2Below
Preferably 1.0 μm2Below, further
Preferably 0.5 μm2The following, particularly preferably 0.2μ
m2It has values in the following ranges: 2 μm2When it exceeds
Sticking is more likely to occur with the card. In addition,
The area of this contour line is the surface shape measurement device by laser interference.
Position, for example, measured with Zygo manufactured by Zygo, Inc.
Is possible.
【0022】本発明においては、上述のようにして基板
または下地層の表面に表面に突起を生成した後、該表面
に機械的テキスチャを施す。機械的テキスチャの程度
は、研削量が0.1mg/cm2 以下、更に望ましくは
0.05mg/cm2 以下、より更に好ましくは0.0
2mg/cm2 以下になるようなテキスチャが好まし
い。この機械的テキスチャの目的は基板が有するポリッ
シュ痕を消すことと、レーザによって作成した凸状突起
の頂部を機械的に研削して鋭い小さな突起を先端に作る
ことである。In the present invention, after the protrusions are formed on the surface of the substrate or the underlayer as described above, the surface is mechanically textured. The extent of mechanical texture is grinding amount is 0.1 mg / cm 2 or less, more preferably 0.05 mg / cm 2 or less, even more preferably 0.0
The texture is preferably 2 mg / cm 2 or less. The purpose of this mechanical texture is to erase the polish marks on the substrate and to mechanically grind the tops of the convex projections produced by the laser to make sharp small projections at the tips.
【0023】本発明においては、上述のようにして基板
または下地層の表面に表面に突起を生成し、さらに機械
的テキスチャを施した後、必要とする下地層、磁気記録
層または保護層を製膜する。本発明において、磁気記録
媒体の基板としては、通常アルミニウム合金板またはガ
ラス基板等の非磁性基板が用いられるが、銅、チタン等
の金属基板、セラミック基板、樹脂基板又はシリコン基
板等を用いることもできる。基板の熱伝導率は、エネル
ギー線照射による熱の冷却の関係から重要であり、好ま
しくは100Watt/mK以下である。In the present invention, the projections are formed on the surface of the substrate or the underlayer as described above, and after mechanical texturing, the required underlayer, magnetic recording layer or protective layer is produced. To film. In the present invention, a non-magnetic substrate such as an aluminum alloy plate or a glass substrate is usually used as the substrate of the magnetic recording medium, but a metal substrate such as copper or titanium, a ceramic substrate, a resin substrate or a silicon substrate may also be used. it can. The thermal conductivity of the substrate is important in terms of heat cooling by irradiation with energy rays, and is preferably 100 Watt / mK or less.
【0024】非磁性基板上に膜厚が通常20〜200n
mのCr、あるいはCu等の下地層を設け、場合によっ
ては基板と上記層との間に更に膜厚が通常100〜2
0,000nmの例えばNiP合金等非磁性体からなる
下地層を設けてもよい。下地層は、通常無電解メッキ法
またはスパッタ法により形成される。また下地層の熱伝
導率、層の厚みもエネルギー線照射による熱の冷却の関
係から重要であり、熱伝導率は好ましくは100Wat
t/mK以下、また、層厚さは好ましくは50〜30,
000nm、特に好ましくは100〜15,000nm
である。The film thickness is usually 20 to 200 n on a non-magnetic substrate.
m of Cr or Cu is provided as an underlayer, and the film thickness is usually 100 to 2 between the substrate and the above layer depending on the case.
You may provide an underlayer which consists of non-magnetic materials, such as a NiP alloy, of 10,000 nm. The underlayer is usually formed by electroless plating or sputtering. Further, the thermal conductivity of the underlayer and the thickness of the layer are also important in terms of the cooling of heat by irradiation with energy rays, and the thermal conductivity is preferably 100 Watt.
t / mK or less, and the layer thickness is preferably 50 to 30,
000 nm, particularly preferably 100 to 15,000 nm
Is.
【0025】磁気記録層は、無電解メッキ、電気メッ
キ、スパッタ、蒸着等の方法によって形成され、Co−
P、Co−Ni−P、Co−Ni−Cr、Co−Ni−
Pt、Co−Cr−Ta、Co−Cr−Pt、Co−C
r−Ta−Pt系合金等の強磁性合金薄膜を形成し、そ
の膜厚は通常30から70nm程度である。The magnetic recording layer is formed by a method such as electroless plating, electroplating, sputtering or vapor deposition.
P, Co-Ni-P, Co-Ni-Cr, Co-Ni-
Pt, Co-Cr-Ta, Co-Cr-Pt, Co-C
A ferromagnetic alloy thin film such as an r-Ta-Pt-based alloy is formed, and its thickness is usually about 30 to 70 nm.
【0026】磁気記録層上には、通常、更に保護層が設
けられるが、保護層としては蒸着、スパッタ、プラズマ
CVD、イオンプレーティング、湿式法等の方法によ
り、炭素膜、水素化カーボン膜、TiC、SiC等の炭
化物膜、SiN、TiN等の窒化膜等、SiO、Al
O、ZrO等の酸化物膜等が成膜される。これらのうち
特に好ましくは、炭素膜、水素化カーボン膜であり、さ
らには、炭素を主成分とし水素の存在比率(H/C、原
子数%)が0.1〜40at%、なかでも1〜30at
%である水素化カーボン膜が好ましい。A protective layer is usually further provided on the magnetic recording layer. As the protective layer, a carbon film, a hydrogenated carbon film, or a carbon film is formed by a method such as vapor deposition, sputtering, plasma CVD, ion plating, or a wet method. Carbide films such as TiC and SiC, nitride films such as SiN and TiN, SiO and Al
An oxide film of O, ZrO, or the like is formed. Of these, a carbon film and a hydrogenated carbon film are particularly preferable, and a hydrogen abundance ratio (H / C, number of atoms%) containing carbon as a main component is 0.1 to 40 at%, and particularly 1 to 30at
% Hydrogenated carbon film is preferred.
【0027】また、保護層上には、通常、潤滑剤層が設
けられる。ただし、スライダー面にダイヤモンド状カー
ボンの層を有する磁気ヘッドを使う場合は、媒体とのト
ライボロジ的な性質が改善されるので、必ずしも保護層
を設ける必要はない。A lubricant layer is usually provided on the protective layer. However, when a magnetic head having a diamond-like carbon layer on the slider surface is used, the tribological property with the medium is improved, so that it is not always necessary to provide a protective layer.
【0028】[0028]
【実施例】次に、実施例により本発明を更に具体的に説
明するが、本発明はその要旨を超えない限り以下の実施
例によって限定されるものではない。 実施例1〜3および比較例1 直径95mmのディスク状Al基板上に膜厚10μmの
NiP(熱伝導率、約10Watt/mK)をメッキし
た後、表面粗さRaが2nm以下になるように表面研磨
を行ってNiP下地層を有する基板を得た。次に、レー
ザの強度163mW、平均照射時間0.6μsec、レ
ーザの集光に用いた対物レンズの開口率NAとして、エ
ネルギーの84%(1/e2 )が集中するスポット径
(1.22×λ/NA)が1.0μm、基板の線速度1
714m/secの範囲内の条件で、ディスクの内周部
の半径18〜21mmのCSS領域にArパルスレーザ
を照射してNiP下地表面にピッチ10μmの渦巻線状
に突起を作成した。なお、Arレーザの波長は488n
mを使用した。EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. Examples 1 to 3 and Comparative Example 1 After plating NiP (thermal conductivity, about 10 Watt / mK) with a film thickness of 10 μm on a disk-shaped Al substrate with a diameter of 95 mm, the surface was adjusted so that the surface roughness Ra was 2 nm or less. Polishing was performed to obtain a substrate having a NiP underlayer. Next, a laser intensity of 163 mW, an average irradiation time of 0.6 μsec, and an aperture ratio NA of the objective lens used for focusing the laser, 84% (1 / e 2 ) of energy is focused on a spot diameter (1.22 ×). λ / NA) 1.0 μm, substrate linear velocity 1
Under the condition of 714 m / sec, an Ar pulse laser was applied to the CSS area having a radius of 18 to 21 mm on the inner peripheral portion of the disk to form spiral protrusions with a pitch of 10 μm on the NiP underlayer surface. The wavelength of the Ar laser is 488n
m was used.
【0029】レーザによる突起生成の後、粒径が約1μ
mの遊離ダイヤモンド砥粒を用い、表−1に記載した研
磨量となるよう基板面に周方向の機械テキスチャを施し
た。図1および図3は、それぞれ実施例1及び比較例1
で得られたNiP下地層の表面形状をレーザ干渉による
表面形状測定装置(米国ザイゴ社製「ZYGO」)で観
察した結果を表す図であり、図2および図4はその断面
図である。After the projections are generated by the laser, the grain size is about 1 μm.
Using free diamond abrasive grains of m, the substrate surface was mechanically textured in the circumferential direction so that the polishing amount shown in Table 1 was obtained. 1 and 3 show Example 1 and Comparative Example 1, respectively.
It is a figure showing the result of having observed the surface shape of the NiP base layer obtained by above with the surface shape measuring apparatus by laser interference ("ZYGO" by a Zigo company, USA), and FIG. 2 and FIG. 4 are the sectional views.
【0030】本発明による突起は図1に示すような形状
を示している。その頂部の形状は、機械的テキスチャに
より削られるため、テキスチャ方向と平行な断面(図2
のa断面)では、レーザによって作成された突起先端形
状よりも滑らかなになっているが、機械的テキスチャ方
向に直角方向の断面(図2のb断面)においては、突起
先端はレーザによって作成された突起を更に細かく分割
されたような形状を有している。The protrusion according to the present invention has a shape as shown in FIG. Since the shape of the top is cut by mechanical texture, a cross section parallel to the texture direction (see FIG. 2).
(A cross section) of the projection is smoother than the shape of the projection tip created by the laser, but in the cross section perpendicular to the mechanical texture direction (cross section b of FIG. 2), the projection tip is created by the laser. The projection has a shape as if it was further divided.
【0031】次いで,スパッタ法により,上記NiP基
板上に、順次、Cr中間層(100nm)、Co−Cr
−Ta合金磁性膜(50nm)を製膜した。さらに、カ
ーボン保護膜を(20nm)を形成し、その後、浸漬法
によりフッ素系液体潤滑剤(モンテエジソン社製「DO
L−2000」)を2nm塗布して、磁気記録媒体を作
製した。Then, a Cr intermediate layer (100 nm) and a Co--Cr layer were sequentially formed on the NiP substrate by a sputtering method.
A -Ta alloy magnetic film (50 nm) was formed. Further, a carbon protective film (20 nm) is formed, and then a fluorine-based liquid lubricant (“DO” manufactured by Monte Edison Co., Ltd. is prepared by an immersion method.
L-2000 ") was applied to a thickness of 2 nm to prepare a magnetic recording medium.
【0032】表−1に実施例と比較例の基板へのレーザ
による突起作成条件、線速度、レーザの強度、レーザの
平均照射時間、平均突起密度(レーザ照射のインターバ
ルに相当)、平均突起高さ、レーザの集光に用いた対物
レンズの開口率NA、およびその後の機械テキスチャに
よる表面の単位面積当りの研削量を示す。Table 1 shows the conditions for forming projections on the substrates of Examples and Comparative Examples by laser, linear velocity, laser intensity, average laser irradiation time, average projection density (corresponding to laser irradiation interval), average projection height. Now, the numerical aperture NA of the objective lens used for focusing the laser and the amount of grinding per unit area of the surface by the subsequent mechanical texture are shown.
【0033】[0033]
【表1】 表−1 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 基板 レーザ 平均 平均 平均 対物 研削量 線速度 強度 照射時間 突起密度 突起高さ レンズ (mm/sec) (mW) (μsec)(個/mm2) (nm) 開口率 (mg/cm2) −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 実施例1 1714 163 0.6 9260 30 0.6 0.03 実施例2 1714 163 0.6 9260 30 0.6 0.02 実施例3 1714 163 0.6 9260 25 0.6 0.18 比較例1 1714 163 0.6 9260 35 0.6 − −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−[Table 1] Table-1 ------------------------------------- Substrate Laser Average Average Average Objective grinding amount Linear velocity Strength Irradiation time Protrusion density Protrusion height Lens (mm / sec) (mW) (μsec) (pieces / mm 2 ) (nm) Aperture ratio (mg / cm 2 ) −−−−−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−− Example 1 1714 163 0.6 9260 30 0.6 0.03 Example 2 1714 163 0.6 9260 30 0.6 0.02 Example 3 1714 163 0.6 9260 25 0.6 0.18 Comparative Example 1 1714 163 0.6 9260 35 0.6 − −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
【0034】表−2にこれらのディスクのCSSテスト
前の静止摩擦係数(初期スティクション)及びCSS2
万回後の摩擦力を示した。CSSテストはヘッド浮上量
1.6μインチ、ロードグラム6gfの薄膜ヘッド(ス
ライダ材質Al2O3TiC)を用いた。CSSゾーン
の安定浮上高さは、全て1.2μインチであった。な
お、実験の条件としては、常温、常湿で行なった。表−
3は、表−2に示した実験を温度が35°C、湿度が8
0%の条件で行なったものである。Table 2 shows the static friction coefficient (initial stiction) and CSS2 before CSS test of these disks.
The frictional force after 10,000 times was shown. For the CSS test, a thin film head (slider material: Al2O3TiC) having a head flying height of 1.6 μinch and a loadgram of 6 gf was used. The stable flying heights of the CSS zones were all 1.2 μ inches. The experimental conditions were normal temperature and normal humidity. Table-
No. 3, the experiment shown in Table-2 was performed at a temperature of 35 ° C and a humidity of 8
It was performed under the condition of 0%.
【0035】[0035]
【表2】 表ほ2 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 初期スティクション CSS2万回後の (摩擦係数) 摩擦力 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 実施例1 0.18 7gf 実施例2 0.24 10gf 実施例3 3.25 25gf 比較例1 0.19 8gf −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−[Table 2] Table 2 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Initial stiction CSS after 20,000 times (Friction coefficient) Frictional force --------------------------------------------- Example 1 0.18 7gf Example 2 0.24 10 gf Example 3 3.25 25 gf Comparative Example 1 0.198 8 gf ------------------------. -----
【0036】[0036]
【表3】 表−3 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 初期スティクション CSS2万回後の (摩擦係数) 摩擦力 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 実施例1 0.20 6gf 実施例2 0.27 8gf 実施例3 5.15 34gf 比較例1 0.25 21gf −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−Table 3 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Initial stiction CSS after 20,000 times (Friction coefficient) Frictional force --------------------------------------------- Example 1 0.20 6gf Example 2 0.27 8gf Example 3 5.15 34gf Comparative Example 1 0.25 21gf ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -----
【0037】[0037]
【発明の効果】本発明によれば、磁気記録媒体の基板ま
たは下地層の表面に先端形状および高さが制御された突
起を作成し、更にその突起先端に機械的にテキスチャを
施すため、形成した突起の先端の面積をさらに小さくす
ることができる、したがって、磁気ヘッド下面と磁気記
録媒体表面との接触面積が少なくなるため、CSS時の
摩擦が極端に小さくなり、また、ヘッドの媒体表面への
スティキングも全く発生しなくなる。特に、高温、高湿
下等の環境テストにおいても安定なCSS特性を示す磁
気記録媒体を得ることができる。According to the present invention, a protrusion whose tip shape and height are controlled is formed on the surface of a substrate or an underlayer of a magnetic recording medium, and the tip of the protrusion is mechanically textured. It is possible to further reduce the area of the tip of the protrusion, and therefore the contact area between the lower surface of the magnetic head and the surface of the magnetic recording medium is reduced, so that the friction during CSS becomes extremely small, and the surface of the medium of the head is reduced. No sticking will occur at all. In particular, it is possible to obtain a magnetic recording medium exhibiting stable CSS characteristics even in environmental tests such as under high temperature and high humidity.
【0038】また、ヘッドのCSS領域のみにこうした
突起を作った場合でも、機械的なテキスチャはデータ記
録領域とCSS領域とを均一に行なうため、それぞれの
平均的な面の高さはほとんど変わらず、ヘッドをデータ
記録領域とCSS領域との間でシークした時にヘッドの
安定浮上高さの変動が少なく、ヘッドクラッシュやヘッ
ドの空間での不安定化が起こらない。Further, even if such a protrusion is formed only in the CSS area of the head, the mechanical texture makes the data recording area and the CSS area uniform, so that the average heights of the respective surfaces hardly change. When the head is sought between the data recording area and the CSS area, the fluctuation of the stable flying height of the head is small, and the head crash and the destabilization in the space of the head do not occur.
【0039】更に、このレーザによる突起の高さや密度
をデータゾーンに近付くにしたがって制御することもで
きるため、ヘッドのデータ記録領域とCSS領域間での
シークは極めて滑らかに行なうことができ、ヘッドのフ
ライングハイトを小さくできる。したがって、高密度の
磁気記録媒体の製造が可能となり、工業的な意義は極め
て大きい。Furthermore, since the height and density of the protrusions produced by the laser can be controlled as they approach the data zone, the seek between the data recording area and the CSS area of the head can be performed extremely smoothly, and the head The flying height can be reduced. Therefore, it becomes possible to manufacture a high-density magnetic recording medium, which is of great industrial significance.
【図1】表面形状装置により観察した本発明の実施例1
のNiP下地層表面の突起の形状を示す斜視図。FIG. 1 is a first example of the present invention observed by a surface profiler.
3 is a perspective view showing the shape of a protrusion on the surface of the NiP underlayer of FIG.
【図2】図1の突起の機械的テキスチャ方向と平行な断
面(a断面)および機械的テキスチャ方向に直角方向の
断面(b断面)を示す図。2 is a view showing a cross section (cross section a) parallel to the mechanical texture direction of the projection of FIG. 1 and a cross section (cross section b) perpendicular to the mechanical texture direction.
【図3】表面形状装置により観察した本発明の比較例1
のNiP下地層表面の突起の形状を示す斜視図。FIG. 3 is a comparative example 1 of the present invention observed by a surface profiler.
3 is a perspective view showing the shape of a protrusion on the surface of the NiP underlayer of FIG.
【図4】図3の突起のディスクの周方向に平行な断面
(a断面)およびディスクの周方向に直角方向の断面
(b断面)を示す図。4 is a view showing a cross section (cross section a) parallel to the circumferential direction of the disk of the protrusion of FIG. 3 and a cross section (cross section b) perpendicular to the circumferential direction of the disk.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 神津 順一 神奈川県横浜市青葉区鴨志田町1000番地 三菱化学株式会社横浜総合研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Kozu 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Mitsubishi Chemical Corporation Yokohama Research Institute
Claims (7)
に、エネルギー線を照射して基板または下地層の表面に
突起を形成した後、基板または下地層の表面に機械的な
テキスチャを施し、その後、必要とする下地層、磁気記
録層または保護層を製膜することを特徴とする磁気記録
媒体の製造方法。1. A surface of a substrate or an underlayer of a magnetic recording medium is irradiated with energy rays to form protrusions on the surface of the substrate or the underlayer, and then the surface of the substrate or the underlayer is mechanically textured. After that, a required underlayer, magnetic recording layer or protective layer is formed into a film, which is a method for producing a magnetic recording medium.
被照射表面において、1回当りの照射時間におけるパル
ス状レーザの走査距離がパルス状レーザのスポット径の
1/2以上である請求項1に記載の磁気記録媒体の製造
方法。2. The energy beam is a pulsed laser,
2. The method for manufacturing a magnetic recording medium according to claim 1, wherein a scanning distance of the pulsed laser on the irradiated surface per irradiation time is ½ or more of a spot diameter of the pulsed laser.
mW以下、1回当りの照射時間が5μsec以下、被照
射表面における集光ビームのスポット径が4μm以下で
あるパルス状レーザであり、被照射表面に対して走査速
度1m/sec以上で相対的に走査する請求項1に記載
の磁気記録媒体の製造方法。3. An energy beam having a laser power of 500
mW or less, irradiation time per time is 5 μsec or less, and the spot diameter of the focused beam on the irradiated surface is 4 μm or less, which is a pulsed laser, and is relatively relative to the irradiated surface at a scanning speed of 1 m / sec or more. The method of manufacturing a magnetic recording medium according to claim 1, wherein scanning is performed.
Watt/mK以下である請求項1ないし3のいずれか
に記載の磁気記録媒体の製造方法。4. The thermal conductivity of the substrate or the base layer is 100.
4. The method for producing a magnetic recording medium according to claim 1, wherein the value is Watt / mK or less.
トアンドストップ)を行なう領域のみに突起を設ける請
求項1ないし4のいずれかに記載の磁気記録媒体の製造
方法。5. The method of manufacturing a magnetic recording medium according to claim 1, wherein the magnetic head is provided with protrusions only in a region where CSS (contact start and stop) is performed.
出力をデータ記録領域に向かって減少させる請求項1な
いし5のいずれかに記載の磁気記録媒体の製造方法。6. The method of manufacturing a magnetic recording medium according to claim 1, wherein the output of energy rays is decreased toward the data recording area in the CSS area.
の掃引を螺旋状に行うことを特徴とする請求項1ないし
6のいずれかに記載の磁気記録媒体の製造方法。7. The method of manufacturing a magnetic recording medium according to claim 1, wherein the medium is disk-shaped, and the energy rays are swept in a spiral shape.
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9699395A JP2970466B2 (en) | 1995-04-21 | 1995-04-21 | Manufacturing method of magnetic recording medium |
DE19524220A DE19524220A1 (en) | 1994-07-04 | 1995-07-03 | Magnetic recording medium allowing head suspension distance to be reduced for hard disc scanning |
KR1019950019855A KR960005459A (en) | 1994-07-04 | 1995-07-03 | Magnetic recording medium, manufacturing method thereof, and recording and reading method |
US08/937,045 US5928759A (en) | 1994-07-04 | 1997-09-24 | Magnetic recording medium, method of producing the same, and recording and reading-out method |
US09/306,909 US6217970B1 (en) | 1994-07-04 | 1999-05-07 | Magnetic recording medium, method of producing the same, and recording and reading-out method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9699395A JP2970466B2 (en) | 1995-04-21 | 1995-04-21 | Manufacturing method of magnetic recording medium |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH08293117A true JPH08293117A (en) | 1996-11-05 |
JP2970466B2 JP2970466B2 (en) | 1999-11-02 |
Family
ID=14179728
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JP9699395A Expired - Fee Related JP2970466B2 (en) | 1994-07-04 | 1995-04-21 | Manufacturing method of magnetic recording medium |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2009031473A1 (en) * | 2007-09-03 | 2009-03-12 | Ngk Insulators, Ltd. | Uniaxially eccentric screw pump rotor |
-
1995
- 1995-04-21 JP JP9699395A patent/JP2970466B2/en not_active Expired - Fee Related
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2009031473A1 (en) * | 2007-09-03 | 2009-03-12 | Ngk Insulators, Ltd. | Uniaxially eccentric screw pump rotor |
JP5456476B2 (en) * | 2007-09-03 | 2014-03-26 | 日本碍子株式会社 | Uniaxial eccentric screw pump rotor |
Also Published As
Publication number | Publication date |
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JP2970466B2 (en) | 1999-11-02 |
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