JPH05282661A - Magnetic recording medium and its production - Google Patents
Magnetic recording medium and its productionInfo
- Publication number
- JPH05282661A JPH05282661A JP7500492A JP7500492A JPH05282661A JP H05282661 A JPH05282661 A JP H05282661A JP 7500492 A JP7500492 A JP 7500492A JP 7500492 A JP7500492 A JP 7500492A JP H05282661 A JPH05282661 A JP H05282661A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- recording medium
- magnetic recording
- protective film
- protective layer
- 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.)
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Links
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- 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、耐久性に優れた磁気記
録媒体及びその製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium having excellent durability and a method for manufacturing the same.
【０００２】[0002]
【発明の背景】最近、コンピュータシステムの外部記憶
装置としての磁気ディスク装置の重要度は高まる一方で
あり、その記録密度は著しい向上を遂げている。このよ
うな磁気ディスク装置の駆動方式は、磁気ディスクが高
速で定速回転している際には、磁気ヘッドが磁気ディス
クから離間した浮上状態にあり、磁気ディスク停止時に
は、磁気ヘッドと磁気ディスクが接触するＣＳＳ（Ｃｏ
ｎｔａｃｔ Ｓｔａｒｔａｎｄ Ｓｔｏｐ）方式が採用
されている。すなわち、磁気ディスクの停止および起動
時には、磁気ヘッドは磁気ディスクに対して摺動してい
る状態にある。2. Description of the Related Art Recently, the importance of a magnetic disk device as an external storage device of a computer system has been increasing, and its recording density has been remarkably improved. In such a drive system of the magnetic disk device, when the magnetic disk is rotating at a high speed and at a constant speed, the magnetic head is in a floating state separated from the magnetic disk, and when the magnetic disk is stopped, the magnetic head and the magnetic disk are separated from each other. Contact CSS (Co
The ntact start and stop method is adopted. That is, when the magnetic disk is stopped and started, the magnetic head is in a state of sliding on the magnetic disk.
【０００３】そして、このような磁気ディスク装置に使
用される磁気ディスクの磁性層は、スパッタリング等の
薄膜形成手段により構成されている。ところで、このよ
うな薄膜形成手段で構成される磁性層は、塗布手段によ
り構成される磁性層のように潤滑剤を内部に含有させて
おくことが困難な為、一般的には潤滑性に乏しい。この
為、磁気ディスクの停止および起動時に作用する摺動力
により磁性層が損傷し易い問題点が有る。The magnetic layer of the magnetic disk used in such a magnetic disk device is composed of thin film forming means such as sputtering. By the way, a magnetic layer formed by such a thin film forming means is generally poor in lubricity because it is difficult to contain a lubricant inside like a magnetic layer formed by a coating means. . Therefore, there is a problem that the magnetic layer is easily damaged by the sliding force that acts when the magnetic disk is stopped and started.
【０００４】このような問題点を解決する為に、従来よ
り、磁性層上に保護膜を設ける手段が提案されている。
例えば、特開昭５３−７６０１３号公報や特公昭５５−
２９５００号公報で提案されている如く、ポリ珪酸やＳ
ｉＯ2 などの酸化物の硬質保護膜を塗布手段やスパッタ
リング等の薄膜形成手段で設ける技術が提案されてい
る。しかしながら、ポリ珪酸やＳｉＯ2 は硬く、摩耗に
対して強いものの、脆く、この為磁気ヘッドの接触によ
る衝撃でポリ珪酸やＳｉＯ2 が欠け、これによる粒子が
磁気ディスクの表面に付着したり、磁気ヘッドの目詰ま
りとなったりし、ヘッドクラッシュの原因とも成り兼ね
ない。In order to solve such a problem, conventionally, a means for providing a protective film on the magnetic layer has been proposed.
For example, JP-A-53-76013 and JP-B-55-
As proposed in Japanese Patent No. 29500, polysilicic acid and S
A technique has been proposed in which a hard protective film of oxide such as iO 2 is provided by a coating means or a thin film forming means such as sputtering. However, although polysilicic acid and SiO 2 are hard and strong against abrasion, they are brittle, and therefore, polysilicic acid and SiO 2 are chipped by the impact of the contact of the magnetic head, resulting in particles adhering to the surface of the magnetic disk or magnetic particles. It may also clog the head and cause a head crash.
【０００５】そこで、このような欠点に対処する為、Ｓ
ｉＣを保護膜として設ける技術が提案（特開昭６２−９
７１２３号公報）されている。しかしながら、この提案
の保護膜でも充分なものでないことが次第に判明して来
た。すなわち、ＣＳＳに対するさらなる高耐久化の要
請、磁気ディスク装置の使用環境の多様化、磁気ヘッド
の高硬度化等に伴い、従来のＳｉＣ膜では硬度不足及び
潤滑性が不足し、信頼性の低下が問題になっている。Therefore, in order to deal with such a defect, S
A technique for providing iC as a protective film is proposed (Japanese Patent Laid-Open No. 62-9).
7123). However, it has gradually been found that the proposed protective film is not sufficient. That is, with the demand for higher durability of CSS, diversification of operating environment of the magnetic disk device, and higher hardness of the magnetic head, the conventional SiC film lacks hardness and lubricity, resulting in deterioration of reliability. It's a problem.
【０００６】[0006]
【発明の開示】前記の問題点に対処する為、本発明者に
より、ガラス状炭素のターゲットをインライン型スパッ
タ装置に装着し、磁気ディスクの磁性層上に成膜させ、
ガラス状炭素に由来するＣ元素を主成分とする素材から
なる保護膜が形成されてなる磁気ディスクの耐久性につ
いての検討が行われた結果、このものは耐久性が高いこ
とが判って来た。そして、さらなる開発が鋭意押し進め
られて行った結果、Ｂ元素を含むガラス状炭素のターゲ
ットをインライン型スパッタ装置に装着し、磁気ディス
クの磁性層上に成膜させ、ガラス状炭素に由来するＣ元
素及びＢ元素を主成分とし、しかも酸化物の量が少なく
制限された素材からなる保護膜が形成されてなる磁気デ
ィスクの耐久性についての検討が行われた結果、この保
護膜はより高硬度なものとなっており、かつ、潤滑性に
も富むものとなっており、摺動特性に優れ、耐久性が著
しく高いことが判って来た。DISCLOSURE OF THE INVENTION In order to solve the above-mentioned problems, the present inventor installed a glassy carbon target in an in-line type sputtering apparatus and formed a film on a magnetic layer of a magnetic disk.
As a result of a study on the durability of a magnetic disk having a protective film made of a material whose main component is C element derived from glassy carbon, it has been found that this has high durability. .. As a result of further intensive development, a glassy carbon target containing B element was attached to an in-line type sputtering apparatus to form a film on the magnetic layer of the magnetic disk, and a C element derived from glassy carbon was formed. As a result of a study on the durability of the magnetic disk having a protective film formed of a material containing B and B as the main components and having a limited amount of oxide, the protective film has a higher hardness. It has been found that it has excellent lubricity, has excellent sliding properties, and has extremely high durability.
【０００７】このような知見を基にして本発明が達成さ
れたものであり、本発明の目的は、耐久性に富む磁気記
録媒体を提供することである。この本発明の目的は、基
板と、この基板上に設けられた磁性層と、その上に設け
られた保護層とを具備してなる磁気記録媒体であって、
前記保護層はＢ元素及びＣ元素を主成分とする素材で構
成されてなり、かつ、この保護層におけるＯ元素量が１
ａｔ％未満であることを特徴とする磁気記録媒体によっ
て達成される。The present invention has been achieved based on such knowledge, and an object of the present invention is to provide a magnetic recording medium having high durability. An object of the present invention is a magnetic recording medium comprising a substrate, a magnetic layer provided on the substrate, and a protective layer provided thereon,
The protective layer is made of a material containing B element and C element as main components, and the amount of O element in the protective layer is 1 or less.
It is achieved by a magnetic recording medium characterized by being less than at%.
【０００８】又、Ｂ元素やＣ元素を成分として含有する
素材をターゲットとして薄膜形成手段により磁性層上に
保護膜を設ける磁気記録媒体の製造方法であって、薄膜
形成時の雰囲気は非酸化性のガス下にあり、このガス圧
は約２〜５ｍＴｏｒｒであって、温度が約１００〜２５
０℃の条件で行われることを特徴とする磁気記録媒体の
製造方法によって達成される。[0008] A method of manufacturing a magnetic recording medium in which a protective film is formed on a magnetic layer by a thin film forming means using a material containing B element or C element as a target as a target, and the atmosphere during the thin film formation is non-oxidizing. The gas pressure is about 2-5 mTorr and the temperature is about 100-25.
This is achieved by a method of manufacturing a magnetic recording medium, which is performed under the condition of 0 ° C.
【０００９】尚、この磁気記録媒体における保護層のＯ
元素量は望ましくは０．８ａｔ％以下、より望ましくは
約０．５ａｔ％以下であることが好ましく、そして保護
層のＣ元素とＢ元素との割合は、Ｃ元素が５０ａｔ％以
上、望ましくは８０ａｔ％以上であることが好ましく、
又、保護層におけるＣ元素はガラス状炭素に由来するも
のであることが好ましい。又、保護層の厚さは約１０〜
３０ｎｍ程度である。The O of the protective layer in this magnetic recording medium is
The element amount is preferably 0.8 at% or less, more preferably about 0.5 at% or less, and the ratio of C element and B element in the protective layer is such that the C element is 50 at% or more, preferably 80 at%. % Or more is preferable,
The C element in the protective layer is preferably derived from glassy carbon. The thickness of the protective layer is about 10
It is about 30 nm.
【００１０】ここで、Ｂ元素及びＣ元素を主成分とする
素材からなる保護層を構成する手段としては、ホウ素含
有炭素製のターゲット、特にホウ素を含有するガラス状
炭素をターゲット材料あるいは蒸着源材料としてスパッ
タリング、イオンビームスパッタリング、蒸着あるいは
イオンプレーティング等の薄膜形成手段で形成させるこ
とにより、又、ガラス状炭素及びホウ素を基にして二元
スパッタあるいは蒸着させることにより形成させること
が出来る。尚、薄膜形成時の雰囲気はＣＨ4 ，Ａｒ，Ｋ
ｒなどの非酸化性雰囲気であることが好ましい。そし
て、このようにしてＢ元素及びＣ元素を主成分とする保
護膜が構成されるに際しては、ターゲット上にコーン状
生成物が出来ることもなく、従って異常放電が起き難
く、安定な放電が期待でき、均質な保護膜が構成され
る。Here, as a means for forming a protective layer made of a material containing B and C elements as main components, a target made of carbon containing boron, particularly glassy carbon containing boron is used as a target material or an evaporation source material. Can be formed by a thin film forming means such as sputtering, ion beam sputtering, vapor deposition or ion plating, or can be formed by binary sputtering or vapor deposition based on glassy carbon and boron. The atmosphere during thin film formation is CH 4 , Ar, K.
A non-oxidizing atmosphere such as r is preferable. When the protective film containing the B element and the C element as the main components is formed in this manner, no cone-shaped product is formed on the target, and therefore abnormal discharge is unlikely to occur and stable discharge is expected. A uniform protective film is formed.
【００１１】本発明で用いられるホウ素含有ガラス状炭
素ターゲットは次のようにして得られる。例えば、フル
フリルアルコール（花王クエーカー（株）製）１０００
部に０．０１１Ｎ−ＨＣｌ水溶液を５部添加し、９６℃
で６時間反応させた後、減圧脱水して熱硬化性樹脂を得
た。この熱硬化性樹脂に、一次粒子の平均粒径が約２０
ｎｍのＢ4 Ｃを加え、ボールミルで分散混合した。得ら
れたフルフリルアルコール初期縮合物樹脂１００部に対
して７０％ｐ−トルエンスルホン酸水溶液１．５部を添
加し、充分に攪拌した。これを厚さ４ｍｍの板状の型に
注入して減圧脱泡した。次に、５０〜６０℃で３時間、
さらに９０℃で５日間加熱した。これにより得られた板
状の複合硬化樹脂を焼成炉に入れ、窒素気流中にて１０
℃／ｈｒの昇温速度で１２００℃まで昇温し、この温度
で２時間保持した後に冷却した。その後、この焼成物を
所定の形状に加工し、ターゲットとした。The boron-containing glassy carbon target used in the present invention is obtained as follows. For example, furfuryl alcohol (Kao Quaker Co., Ltd.) 1000
5 parts of 0.011 N-HCl aqueous solution was added to the parts, and 96 ° C.
After reacting for 6 hours, it was dehydrated under reduced pressure to obtain a thermosetting resin. This thermosetting resin has an average primary particle size of about 20
nm B 4 C was added and dispersed and mixed by a ball mill. To 100 parts of the obtained furfuryl alcohol initial condensate resin, 1.5 parts of a 70% aqueous p-toluenesulfonic acid solution was added and sufficiently stirred. This was poured into a plate-shaped mold having a thickness of 4 mm and degassed under reduced pressure. Next, at 50-60 ° C for 3 hours,
It was further heated at 90 ° C. for 5 days. The plate-shaped composite cured resin thus obtained was placed in a firing furnace and heated in a nitrogen stream for 10
The temperature was raised to 1200 ° C. at a heating rate of ° C./hr, and the temperature was maintained for 2 hours and then cooled. After that, the fired product was processed into a predetermined shape and used as a target.
【００１２】又、Ｂ4 Ｃ粉末とＣ1 （コークス粉末）と
をボールミルにより混合し、この混合粉末をターゲット
状に加圧成形し、この成形体をＡｒガスなどの不活性雰
囲気中において約２５００℃の温度で焼成することによ
り得られるＢ含有黒鉛製のターゲットを用いることも出
来る。以下、実施例を挙げて本発明を具体的に説明す
る。Further, B 4 C powder and C 1 (coke powder) are mixed by a ball mill, the mixed powder is pressure-molded into a target, and the compact is subjected to about 2500 in an inert atmosphere such as Ar gas. It is also possible to use a B-containing graphite target obtained by firing at a temperature of ° C. Hereinafter, the present invention will be specifically described with reference to examples.
【００１３】[0013]
〔実施例１〕インライン型スパッタ装置を用い、そして
上記したような製造方法で得られたＢ含有ガラス状炭素
をターゲットとし、Ａｌ基板−Ｎｉ・Ｐメッキ膜−Ｃｒ
膜（５０ｎｍ）−ＣｏＣｒＴａ磁性膜（４０ｎｍ）から
なる磁気ディスクのＣｏＣｒＴａ磁性膜面上にＢ含有ガ
ラス状炭素に由来するＣ元素及びＢ元素からなる保護膜
を２０ｎｍ厚形成し、本発明になる磁気ディスクを得
た。[Example 1] Using an in-line type sputtering apparatus and targeting the B-containing glassy carbon obtained by the above-described manufacturing method, Al substrate-Ni / P plating film-Cr
Film (50 nm) -CoCrTa magnetic film (40 nm) of a magnetic disk, a protective film made of C element and B element derived from B-containing glassy carbon having a thickness of 20 nm is formed on the CoCrTa magnetic film surface of the magnetic disk to form a magnetic film according to the present invention. I got a disc.
【００１４】保護膜形成の為のスパッタ条件 基板温度：２５０℃ Ａｒガス圧：４ｍＴｏｒｒ 〔実施例２〕インライン型スパッタ装置を用い、そして
上記したような製造方法で得られたＢ含有黒鉛をターゲ
ットとし、Ａｌ基板−Ｎｉ・Ｐメッキ膜−Ｃｒ膜（５０
ｎｍ）−ＣｏＣｒＴａ磁性膜（４０ｎｍ）からなる磁気
ディスクのＣｏＣｒＴａ磁性膜面上にＢ含有黒鉛に由来
するＣ元素及びＢ元素からなる保護膜を２０ｎｍ厚形成
し、本発明になる磁気ディスクを得た。Sputtering Conditions for Forming Protective Film Substrate temperature: 250 ° C. Ar gas pressure: 4 mTorr [Example 2] A B-containing graphite obtained by the above-described manufacturing method using an in-line type sputtering apparatus as a target. , Al substrate-Ni / P plating film-Cr film (50
nm) -CoCrTa magnetic film (40 nm), a protective film made of C element and B element derived from B-containing graphite having a thickness of 20 nm was formed on the CoCrTa magnetic film surface of the magnetic disk to obtain the magnetic disk of the present invention. ..
【００１５】保護膜形成の為のスパッタ条件 基板温度：２００℃ Ａｒガス圧：３ｍＴｏｒｒ 〔比較例１〕実施例１において、保護膜形成の為のスパ
ッタ条件を、 基板温度：２５０℃ Ａｒガス圧：６ｍＴｏｒｒ とした他は同様に行った。Sputtering conditions for forming a protective film Substrate temperature: 200 ° C. Ar gas pressure: 3 mTorr [Comparative Example 1] In Example 1, the sputtering conditions for forming a protective film were: substrate temperature: 250 ° C. Ar gas pressure: The same procedure was performed except that the pressure was set to 6 mTorr.
【００１６】〔比較例２〕実施例２において、保護膜形
成の為のスパッタ条件を、 基板温度：２５０℃ Ａｒガス圧：８ｍＴｏｒｒ とした他は同様に行った。[Comparative Example 2] The same procedure as in Example 2 was carried out, except that the sputtering conditions for forming the protective film were a substrate temperature: 250 ° C., an Ar gas pressure: 8 mTorr.
【００１７】〔比較例３〕実施例２において、保護膜形
成の為のスパッタ条件を、 基板温度：２８０℃ Ａｒガス圧：８ｍＴｏｒｒ とした他は同様に行った。[Comparative Example 3] The same procedure as in Example 2 was carried out except that the sputtering conditions for forming the protective film were the substrate temperature: 280 ° C., the Ar gas pressure: 8 mTorr.
【００１８】〔特性〕上記各例で得られた磁気ディスク
について、保護膜のＢ，Ｃ，Ｏ各元素の組成を調べたの
で、その結果を表１に示した。すなわち、組成が既知の
膜を用意し、ＥＳＣＡによりＢ，Ｃ及びＯ1Sのピーク強
度を測定し、各強度の相対感度係数を算出した。又、各
例の磁気ディスクの保護膜についてもＥＳＣＡにより
Ｂ，Ｃ及びＯ1Sのピーク強度を測定し、保護膜における
各元素の組成比を算出した。尚、測定した膜は予めＸｅ
イオンによりエッチングし、表面吸着層を取り、清浄に
しておいた。[Characteristics] With respect to the magnetic disks obtained in the above examples, the compositions of the B, C and O elements in the protective film were examined. The results are shown in Table 1. That is, a film having a known composition was prepared, the peak intensities of B, C and O 1S were measured by ESCA, and the relative sensitivity coefficient of each intensity was calculated. Also, with respect to the protective film of the magnetic disk of each example, the peak intensities of B, C and O 1S were measured by ESCA, and the composition ratio of each element in the protective film was calculated. In addition, the measured film has Xe in advance.
It was etched with ions to remove the surface adsorption layer and kept clean.
【００１９】 表 １（各元素の組成、原子比） Ｂ元素 Ｃ元素 Ｏ元素 実施例１ １５ ８５ ０．２以下 実施例２ １５ ８５ ０．５以下 比較例１ １５ ８４ １ 比較例２ １５ ８４ １ 比較例３ １４ ８２ ３ 又、各例の磁気ディスクについて、ＣＳＳテストを行っ
たので、その結果を表２に示す。Table 1 (Composition and atomic ratio of each element) B element C element O element Example 1 15 85 0.2 or less Example 2 15 85 0.5 0.5 or less Comparative Example 1 15 84 1 Comparative Example 2 15 84 1 Comparative Example 3 14 82 3 A CSS test was conducted on the magnetic disks of the respective examples, and the results are shown in Table 2.
【００２０】表２ ＣＳＳテスト中にディスクに傷が発生、又はヘッドとの
摩擦形数が０．５を越えた際のＣＳＳ回数 実施例１ ８００００回以上 実施例２ ６００００回（摩擦形数が０．
５を越えた） 比較例１ ３００００回（摩擦形数が０．
５を越えた） 比較例２ １００００回（摩擦形数が０．
５を越えた） 比較例３ ５０００回（ヘッドに傷が観
察） ＣＳＳテスト条件 ヘッド：３３８０型Ａ１2 ０3 ・ＴｉＣヘッド ヘッド荷重：１０ｇ ＣＳＳテスト１回のサイクル：０ｒｐｍ〜３６００ｒｐ
ｍ （５ｓｅｃ） ３６００ｒｐｍ （１ｓｅｃ） ３６００ｒｐｍ〜０ｒｐｍ （５ｓｅｃ） ０ｒｐｍ （１ｓｅｃ） この表１及び表２から、Ｃ元素及びＢ元素を主成分とす
る素材で構成された保護膜におけるＯ元素が１％未満の
少ないものである場合には、耐久性に著しく優れている
ことが判る。Table 2 Number of CSSs when scratches were generated on the disk during the CSS test or the number of friction types with the head exceeded 0.5 Example 1 80,000 times or more Example 2 60,000 times (the number of friction types was 0 ．
Comparative Example 1 30000 times (friction type number was less than 0.5).
Comparative Example 2 10000 times (friction type number was less than 0.5).
5 beyond a) Comparative Example 3 5000 times (scratches head observation) CSS Test Conditions head: 3380 Type A1 2 0 3 · TiC Head Head load: 10 g CSS test one cycle: 0Rpm～3600rp
m (5 sec) 3600 rpm (1 sec) 3600 rpm to 0 rpm (5 sec) 0 rpm (1 sec) From Table 1 and Table 2, the O element in the protective film composed of the material containing the C element and the B element as the main components is less than 1%. It can be seen that the durability is remarkably excellent in the case of a small amount.
【００２１】[0021]
【効果】本発明の磁気記録媒体は、耐久性に富み、か
つ、記録再生装置に悪影響が起きないものである。The magnetic recording medium of the present invention has a high durability and does not adversely affect the recording / reproducing apparatus.
Claims (4)
と、その上に設けられた保護層とを具備してなる磁気記
録媒体であって、前記保護層はＢ元素及びＣ元素を主成
分とする素材で構成されてなり、かつ、この保護層にお
けるＯ元素の量が１ａｔ％未満であることを特徴とする
磁気記録媒体。1. A magnetic recording medium comprising a substrate, a magnetic layer provided on the substrate, and a protective layer provided thereon, the protective layer containing B element and C element. A magnetic recording medium comprising a material having a main component, wherein the amount of O element in the protective layer is less than 1 at%.
は、Ｃ元素が５０ａｔ％以上であることを特徴とする請
求項１の磁気記録媒体。2. The magnetic recording medium according to claim 1, wherein the ratio of the C element and the B element in the protective layer is such that the C element is 50 at% or more.
由来するものであることを特徴とする請求項１または請
求項２の磁気記録媒体。3. The magnetic recording medium according to claim 1 or 2, wherein the C element in the protective layer is derived from glassy carbon.
材をターゲットとして薄膜形成手段により磁性層上に保
護膜を設ける磁気記録媒体の製造方法であって、薄膜形
成時の雰囲気は非酸化性のガス下にあり、このガス圧は
約２〜５ｍＴｏｒｒであって、温度が約１００〜２５０
℃の条件で行われることを特徴とする磁気記録媒体の製
造方法。4. A method for producing a magnetic recording medium, wherein a protective film is provided on a magnetic layer by means of a thin film forming means using as a target a material containing element B or element C as a component, wherein the atmosphere during thin film formation is non-oxidizing. The gas pressure is about 2-5 mTorr and the temperature is about 100-250.
A method of manufacturing a magnetic recording medium, which is performed under the condition of ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7500492A JPH05282661A (en) | 1992-03-31 | 1992-03-31 | Magnetic recording medium and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7500492A JPH05282661A (en) | 1992-03-31 | 1992-03-31 | Magnetic recording medium and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05282661A true JPH05282661A (en) | 1993-10-29 |
Family
ID=13563625
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7500492A Pending JPH05282661A (en) | 1992-03-31 | 1992-03-31 | Magnetic recording medium and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05282661A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5552204A (en) * | 1995-01-13 | 1996-09-03 | International Business Machines Corporation | Magnetic disk with boron carbide overcoat layer |
-
1992
- 1992-03-31 JP JP7500492A patent/JPH05282661A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5552204A (en) * | 1995-01-13 | 1996-09-03 | International Business Machines Corporation | Magnetic disk with boron carbide overcoat layer |
| US5750231A (en) * | 1995-01-13 | 1998-05-12 | International Business Machines Corporation | Magnetic disk with boron carbide overcoat layer |
| US5897931A (en) * | 1995-01-13 | 1999-04-27 | International Business Machines Corporation | Magnetic disk with boron carbide overcoat layer |
| US6010601A (en) * | 1995-01-13 | 2000-01-04 | International Business Machines Corporation | Method of making magnetic disk with boron carbide overcoat layer and adhesion layer |
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