【発明の詳細な説明】本発明は、高密度記録φ再生用の薄膜磁気ディスク基板
に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thin film magnetic disk substrate for high-density recording φ reproduction.
従来、スパッタ、メッキ、イオンブレーティング等の薄
膜形成技術を用いて、磁性薄膜を形成してなる磁気ディ
スク用基板としては、アルミ合金表面をアルマイト被覆
し、これを鏡面仕上げしたものや、あるいはアルミ合金
表面にＮ１−Ｐメッキを数ｌＯμｍの厚さに施して、こ
れを研削、ラップ、ポリシュ等の加工手段を用いて表面
粗さＲａ０．００５μｍ以下の鏡面にしたものが使用さ
れてきた（第１図（ａ）参照）。Conventionally, magnetic disk substrates made by forming magnetic thin films using thin film forming techniques such as sputtering, plating, and ion blating have been made by coating an aluminum alloy surface with alumite and finishing it with a mirror finish, or by coating aluminum alloy surfaces with anodized aluminum. It has been used to apply N1-P plating to a thickness of several 10 μm on the alloy surface, and use processing methods such as grinding, lapping, and polishing to create a mirror surface with a surface roughness Ra of 0.005 μm or less. (See Figure 1(a)).
しかしながら、高密度記録化に伴ない、磁気ヘッド浮上
隙間の低減が要求される一方、磁気ヘッドのコンタクト
・ストップ時に、磁気ヘッドと、磁気ディスク間の微小
隙間の潤滑剤、或いは吸着水分の表面張力によシ磁気ヘ
ッドが吸着されて、次のディスク起動時に損傷を引き起
すことがあった。However, with higher density recording, it is required to reduce the flying gap of the magnetic head, but when the magnetic head contacts and stops, the surface tension of lubricant or adsorbed moisture in the minute gap between the magnetic head and the magnetic disk increases. Otherwise, the magnetic head could be attracted, causing damage when the next disk was started.
すなわち、従来の磁気ディスク基板に、磁性薄膜を形成
し、液体又は固体潤滑剤を塗布した場合、ディスク表面
に潤滑剤の溜ｐ場がないために、磁気ディスクの回転中
に、潤滑剤が飛散消失したシ、殊に液体潤滑剤では、磁
気ヘッドのコンタクト・ストップ時に磁気ヘッドと鏡面
仕上げした磁気ディスクとの微小隙間に存在する潤滑剤
あるいは吸着水分の表面張力によシ磁気ヘッドが吸着さ
れる。従って次のディスク起動時に磁気ヘッド、磁気デ
ィスクの損傷ｔ−まねく惧れがある。In other words, when a magnetic thin film is formed on a conventional magnetic disk substrate and a liquid or solid lubricant is applied, the lubricant scatters while the magnetic disk rotates because there is no lubricant reservoir on the disk surface. When the magnetic head disappears, especially with a liquid lubricant, the magnetic head is attracted by the surface tension of the lubricant or adsorbed moisture that exists in the minute gap between the magnetic head and the mirror-finished magnetic disk when the magnetic head makes contact and stops. . Therefore, there is a risk that the magnetic head and magnetic disk will be damaged when the next disk is started.
そこで、上述した弊害を避けるため、磁気ディスク表面
粗さを粗くすることも考えられるが、所定以上に表面粗
さを粗くすることは、低浮上隙間で動作する磁気ヘッド
の浮上安定性を損ねる突起が増加し、さらに信号Ｏ８Ｎ
比低下、或いはエラー特性が劣化する等の欠点があった
。Therefore, in order to avoid the above-mentioned disadvantages, it is possible to increase the surface roughness of the magnetic disk, but increasing the surface roughness beyond a certain level may cause protrusions that impair the flying stability of the magnetic head that operates with a low flying clearance. increases, and further the signal O8N
There were drawbacks such as a decrease in ratio or deterioration of error characteristics.
本発明は、上述した従来の欠点を解決するために、磁気
ディスク基板表面を適度に粗面化し、磁気ヘッドとの摩
擦係数及び潤滑剤の飛散消失や表面張力による吸着力を
小さく保ち、信号ＳＮ比の劣化がなく、しかも信号エラ
ーとなる欠陥のない磁気ディスク基板を提供するもので
ある。In order to solve the above-mentioned conventional drawbacks, the present invention has been developed by appropriately roughening the surface of the magnetic disk substrate, keeping the coefficient of friction with the magnetic head, the scattering loss of lubricant, and the adsorption force due to surface tension small, thereby reducing the signal SN. To provide a magnetic disk substrate which is free from deterioration in ratio and also free from defects that may cause signal errors.
以下、本発明を実施例に基づいて詳細に説明する。Hereinafter, the present invention will be explained in detail based on examples.
本発明は磁気ディスクのアルミ合金基板上に表面被覆を
施し、この表面を所定の表面粗さの範囲に成形する（第
１図（ｂ）参照）。ここで上記表面粗さの範囲について
は第２図に示すように所定の範囲において摩擦係数、吸
着力に関して大幅な相違がみられる。In the present invention, a surface coating is applied to an aluminum alloy substrate of a magnetic disk, and this surface is formed to have a predetermined surface roughness range (see FIG. 1(b)). As for the range of surface roughness mentioned above, as shown in FIG. 2, there are significant differences in the friction coefficient and adsorption force within a predetermined range.
第２図は本発明の実施例による効果を示す磁気ディスク
基板の表面粗さｈ（μｍ）と、磁気ヘッドとの吸着力（
１ｆ）及び磁気ディスク媒体の摩擦係数との測定結果で
ある。Figure 2 shows the effect of the embodiment of the present invention, showing the surface roughness h (μm) of the magnetic disk substrate and the adsorption force (μm) with the magnetic head.
1f) and the friction coefficient of the magnetic disk medium.
すなわち、Ｎ１−Ｐメッキ面を研削、ラップ及びポリシ
ュによシ鏡面仕上げした表面粗さＲａＯ，００５μｍの
従来型の８インチ基板、及びポリシュの砥粒粒度を変え
て仕上げ表面粗さＲａ Ｏ，００６〜０．０１４μｍま
で振った８インチ基板を用意し、これに湿式によるＣｏ
−Ｎ１−Ｐ磁性メッキ膜を０．０８μｍに形成するとと
もに、ＲＦスパッタによ、り Ｓｉｎ、保護膜を０．０
８μｍ施し、その上に潤滑剤としてデュポン社りライト
ツクスＡＣ等所定のＯ，Ｏ１％フレオン溶液をスピンコ
ー）して試料を作成する。That is, a conventional 8-inch substrate with a surface roughness of RaO, 005 μm in which the N1-P plated surface was ground, lapped, and polished to a mirror finish, and a finished surface roughness of RaO, 006 by changing the abrasive grain size of the polish. An 8-inch substrate shaken to ~0.014 μm was prepared, and Co was applied to it by a wet method.
-N1-P magnetic plating film was formed to a thickness of 0.08 μm, and a protective film of 0.0 μm was formed using RF sputtering.
A sample is prepared by applying a predetermined O, O 1% Freon solution such as DuPont's Litex AC as a lubricant thereon by spin coating.
上述した試料を各表面粗さＲａ値毎３枚ずつ作成し、Ｍ
ｎ−Ｚｎフェライト製テーパフラットタイプの磁気ヘッ
ド（負荷６ｆｆ）との摩擦係数及び同磁気５ツドをコン
タクト状態にしたま＼常温常湿に保持し、２４時間後に
磁気ヘッドと磁気ディスクを低速でずらすに要する吸着
力を測定した結果をまとめたものである。Three samples were prepared for each surface roughness Ra value, and M
The coefficient of friction with a tapered flat type magnetic head made of n-Zn ferrite (6ff load) and the same magnetic 5-pin are maintained at room temperature and humidity in a state of contact, and after 24 hours the magnetic head and magnetic disk are shifted at low speed. This is a summary of the results of measuring the adsorption force required.
図からも明らかなように、表面粗さＲａが０．００５μ
ｍから０．００６μｍに増加すると、急激に摩擦係数と
吸着力は低下し、以後Ｒａの増加とともに、両値は徐々
に低下していく。特に摩擦係数はＲａＯ，０１０μｍ以
上で一定値を示している。As is clear from the figure, the surface roughness Ra is 0.005μ
When increasing from m to 0.006 μm, the friction coefficient and adsorption force suddenly decrease, and thereafter, as Ra increases, both values gradually decrease. In particular, the friction coefficient shows a constant value above RaO, 010 μm.
これは、基板の粗面化によシ潤滑剤の溜り場が多く形成
されるためである。This is because many lubricant reservoirs are formed due to the roughened surface of the substrate.
一方、基板の粗面化とともに、信号ＳＮ比の低下、信号
エラーとなる欠陥の増加が懸念されるため、上記磁気デ
ィスクと磁気ヘッドとの組合わせで、両特性の測定を行
なった。この結果を第３図に示す。On the other hand, since there is a concern that as the surface of the substrate becomes rougher, the signal-to-noise ratio decreases and defects that cause signal errors increase, both characteristics were measured using the combination of the magnetic disk and magnetic head described above. The results are shown in FIG.
ここで、信号エラーとなる欠陥測定は、ヘッドトラック
幅１７μｍ、）ラックピッチ２５μｍ、ディスク回当ｐ
２２００ ）ラック、ヘッド浮上隙間０．２５μｍ１信
号記録密度６００ ｂｉｔ／ｍ。Here, the defect measurement that causes a signal error is as follows: head track width 17 μm, rack pitch 25 μm, disk rotation p
2200) Rack, head flying gap 0.25 μm 1 signal recording density 600 bit/m.
ディスク回転数３６０ Ｏｒｐｍ、信号エラーとする信
号レベル（スライスレベル）ｋ６０％として測定した結
果である。This is the result of measurement at a disk rotation speed of 360 Orpm and a signal level (slice level) k60% to be considered as a signal error.
上述した第２図の結果から、表面粗さＲａが０．００５
μｍから増加するに従い、欠陥数は徐々に劣化していく
が、０．０１０μｍを越えると急激に劣化する。From the results shown in Figure 2 above, the surface roughness Ra is 0.005.
As the number of defects increases from μm, the number of defects gradually deteriorates, but when it exceeds 0.010 μm, it rapidly deteriorates.
また、信号のＳＮ比はＲａがｏ、ｏｉｏμｍまでは、は
とんど変化せず、０．０１０μｍ’ｒ越えるとやや劣化
する。Further, the signal-to-noise ratio of the signal hardly changes until Ra reaches o or oioμm, and deteriorates slightly when it exceeds 0.010μm'r.
さらに、磁気ディスク表面の突起に関しては、潤滑剤塗
布後にサファイア製スライダを用いて１５分間パニシュ
した後、ＡＥ素子を応用したディスク表面突起物検査装
置上用いてディスク全面を検査したところ、磁気ヘッド
の浮上隙間０．２μｍでは突起との接触箇所は０であシ
、０．１５μｍでは表面粗さＲａが０．０１０μｍを越
えた場合のみ１〜１０箇所／面が検出された。Furthermore, regarding protrusions on the surface of the magnetic disk, after applying lubricant and punishing for 15 minutes using a sapphire slider, the entire surface of the disk was inspected using a disk surface protrusion inspection device that applied an AE element. At a floating gap of 0.2 μm, there were no contact points with the protrusion, and at 0.15 μm, 1 to 10 points/surface were detected only when the surface roughness Ra exceeded 0.010 μm.
以上詳細に説明したように、本発明の高密度記録・再生
用の薄膜磁気ディスク基板は、基板の表面粗さＲａを０
．００６〜０．０ＩＯμｍとすることによシ、磁気ディ
スクと磁気ヘッドとの摩擦係数及び磁気ヘッドの吸着力
を小さく保持することができるとともに、信号ＳＮ比の
劣化及び、信号エラーとなる欠陥が少なく、しかも磁気
ヘッド浮上安定性を損うディスク表面突起を少なくする
ことができる等の効果を奏する。As explained in detail above, the thin film magnetic disk substrate for high-density recording and reproduction of the present invention has a surface roughness Ra of 0.
．． By setting it to 0.006 to 0.0 IO μm, the coefficient of friction between the magnetic disk and the magnetic head and the adsorption force of the magnetic head can be kept small, and there is less deterioration of the signal-to-noise ratio and defects that cause signal errors. Moreover, it is possible to reduce the number of protrusions on the disk surface that impair the flying stability of the magnetic head.
第１図（ａ） （ｂ）は磁気ディスク基板表面の粗さ曲
線を示すグラフであシ、（ａ）は従来の例、（ｂ）は本
発明の例を示す。第２図は磁気ディスク基板の表面粗さ
Ｒａとディスク媒体の摩擦係数および磁気ヘッドの吸着
力との関係を示すグラフ、第３図は磁気ディスク基板の
表面粗さＲａと信号欠陥箇所数、ＳＮ比との関係を示す
グラフである。特許出願人 日本電信電話公社代理人 弁理士 光 石 士 部（他１名）第１図（ａ）（ｂ）第２図・“［ｌ？「FIGS. 1(a) and 1(b) are graphs showing roughness curves of the surface of a magnetic disk substrate, where (a) shows a conventional example and (b) shows an example of the present invention. Fig. 2 is a graph showing the relationship between the surface roughness Ra of the magnetic disk substrate, the friction coefficient of the disk medium, and the adsorption force of the magnetic head, and Fig. 3 is a graph showing the relationship between the surface roughness Ra of the magnetic disk substrate and the number of signal defects, SN It is a graph showing the relationship with the ratio. Patent Applicant Nippon Telegraph and Telephone Public Corporation Agent Patent Attorney Mitsuishi Shibu (and 1 other person) Figure 1 (a) (b) Figure 2 "[l?"
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57190737AJPS5982626A (en) | 1982-11-01 | 1982-11-01 | Substrate for magnetic disk |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57190737AJPS5982626A (en) | 1982-11-01 | 1982-11-01 | Substrate for magnetic disk |
| Publication Number | Publication Date |
|---|---|
| JPS5982626Atrue JPS5982626A (en) | 1984-05-12 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57190737APendingJPS5982626A (en) | 1982-11-01 | 1982-11-01 | Substrate for magnetic disk |
| Country | Link |
|---|---|
| JP (1) | JPS5982626A (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61220119A (en)* | 1985-03-26 | 1986-09-30 | Sony Corp | Magnetic disk |
| JPS6361409A (en)* | 1986-09-01 | 1988-03-17 | Hitachi Ltd | Magnetic recording medium |
| US4803577A (en)* | 1985-06-12 | 1989-02-07 | Tdk Corporation | Vertical magnetic recording system using rigid disk |
| JPH06203371A (en)* | 1992-12-28 | 1994-07-22 | Nec Corp | Magnetic recording medium |
| JPH06342520A (en)* | 1994-01-13 | 1994-12-13 | Fuji Electric Co Ltd | Production of magnetic disk |
| US5626970A (en)* | 1985-11-12 | 1997-05-06 | Hedgcoth; Virgle L. | Sputtered magnetic thin film recording disk |
| US5825591A (en)* | 1993-07-23 | 1998-10-20 | Hitachi, Ltd. | Frictionally sliding head magnet disk apparatus |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56114125A (en)* | 1980-02-14 | 1981-09-08 | Hitachi Ltd | Substrate for magnetic recording medium and its production |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56114125A (en)* | 1980-02-14 | 1981-09-08 | Hitachi Ltd | Substrate for magnetic recording medium and its production |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61220119A (en)* | 1985-03-26 | 1986-09-30 | Sony Corp | Magnetic disk |
| US4803577A (en)* | 1985-06-12 | 1989-02-07 | Tdk Corporation | Vertical magnetic recording system using rigid disk |
| US4908727A (en)* | 1985-06-12 | 1990-03-13 | Tdk Corporation | Disk with substrate of alumina silicate resin glass |
| US5626970A (en)* | 1985-11-12 | 1997-05-06 | Hedgcoth; Virgle L. | Sputtered magnetic thin film recording disk |
| US6036824A (en)* | 1985-11-12 | 2000-03-14 | Magnetic Media Development Llc | Magnetic recording disk sputtering process and apparatus |
| JPS6361409A (en)* | 1986-09-01 | 1988-03-17 | Hitachi Ltd | Magnetic recording medium |
| JPH06203371A (en)* | 1992-12-28 | 1994-07-22 | Nec Corp | Magnetic recording medium |
| US5825591A (en)* | 1993-07-23 | 1998-10-20 | Hitachi, Ltd. | Frictionally sliding head magnet disk apparatus |
| JPH06342520A (en)* | 1994-01-13 | 1994-12-13 | Fuji Electric Co Ltd | Production of magnetic disk |
| Publication | Publication Date | Title |
|---|---|---|
| JPH01251308A (en) | Floating magnetic head and its manufacture | |
| US4820584A (en) | Magnetic recording medium and method of manufacturing the same | |
| JPH04339312A (en) | magnetic disk | |
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