JPH0430325A - Production of magnetic disk substrate - Google Patents
Production of magnetic disk substrateInfo
- Publication number
- JPH0430325A JPH0430325A JP13676590A JP13676590A JPH0430325A JP H0430325 A JPH0430325 A JP H0430325A JP 13676590 A JP13676590 A JP 13676590A JP 13676590 A JP13676590 A JP 13676590A JP H0430325 A JPH0430325 A JP H0430325A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic disk
- aluminum
- hydrofluoric acid
- anodic oxide
- disk substrate
- 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.)
- Pending
Links
- 239000000758 substrate Substances 0.000 title claims abstract description 34
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims abstract description 40
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 31
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 31
- 229910052751 metal Inorganic materials 0.000 claims abstract description 18
- 239000002184 metal Substances 0.000 claims abstract description 18
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 10
- 239000010407 anodic oxide Substances 0.000 claims description 28
- 238000000034 method Methods 0.000 claims description 12
- 239000011259 mixed solution Substances 0.000 claims description 7
- 239000000243 solution Substances 0.000 claims description 6
- 238000005530 etching Methods 0.000 abstract description 16
- 229910000838 Al alloy Inorganic materials 0.000 abstract description 6
- 239000000203 mixture Substances 0.000 abstract description 5
- 230000015572 biosynthetic process Effects 0.000 abstract description 3
- 239000010408 film Substances 0.000 description 25
- 239000002244 precipitate Substances 0.000 description 16
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 229910052802 copper Inorganic materials 0.000 description 6
- 239000010949 copper Substances 0.000 description 6
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 4
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 3
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 3
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 239000006061 abrasive grain Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 229910052718 tin Inorganic materials 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000007743 anodising Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- SZMZREIADCOWQA-UHFFFAOYSA-N chromium cobalt nickel Chemical compound [Cr].[Co].[Ni] SZMZREIADCOWQA-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910000365 copper sulfate Inorganic materials 0.000 description 1
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Magnetic Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、磁気ディスク装置に用いられる磁気ディス
クの基板を製造する方法に関し、アルミニウム陽極酸化
被膜の微細孔に非磁性金属を充填したのち、この表面を
エツチングして、非磁性金属を表面から突出させて、微
小凹凸を形成させる際、前記エツチングの工、チャント
としてフッ酸液またはフッ酸、硝酸混液を用いることに
よってアルミニウム中に含まれる異物や析出物を除去し
、微小凹凸面から突出する突起を除去するようにしたち
のである。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a magnetic disk substrate used in a magnetic disk device, in which micropores in an aluminum anodic oxide film are filled with a non-magnetic metal, and then When this surface is etched to make the non-magnetic metal protrude from the surface and form minute irregularities, foreign matter contained in the aluminum is removed by using a hydrofluoric acid solution or a mixed solution of hydrofluoric acid and nitric acid as a chant during the etching process. This method removes deposits and precipitates, and removes protrusions that protrude from the micro-asperity surface.
磁気ディスクの製法の一つに、特開平1−165025
号公報に開示されたものかある。One of the manufacturing methods for magnetic disks is Japanese Patent Application Laid-Open No. 1-165025.
Is there something that was disclosed in the publication?
この方法は、第4図に示すようにアルミニウムやアルミ
ニウム合金なとの基板1に陽極酸化処理を施し、その表
面に無数の微細孔2・・・が形成されたアルミニウム陽
極酸化被膜3を形成する。ついて、この基板lのアルミ
ニウム[i酸(1[膜3の微細孔2・・に第5図に示す
ように、銅、スズ、亜鉛などの非磁性金属4を電解処理
して析出充填させる。次に、この陽極酸化被膜3を表面
を軽く研磨したのち、酸化アルミニウムからなる陽極酸
化被膜3のみをリン酸・クロム酸混合液または水酸化ナ
トリウム水溶液などによってエツチング処理して除去す
る。これにより、第6図に示すように、針状の非磁性金
属4が陽極酸化被膜3表面から突出した状態となり、基
板表面に二次元の微小凹凸が形成される。In this method, as shown in Fig. 4, a substrate 1 made of aluminum or an aluminum alloy is subjected to anodizing treatment, and an aluminum anodic oxide film 3 with numerous micropores 2 formed on its surface is formed. . Then, as shown in FIG. 5, a nonmagnetic metal 4 such as copper, tin, or zinc is precipitated and filled into the micropores 2 of the aluminum film 3 of the substrate 1 by electrolytic treatment. Next, after lightly polishing the surface of this anodic oxide film 3, only the anodic oxide film 3 made of aluminum oxide is removed by etching with a phosphoric acid/chromic acid mixture or an aqueous sodium hydroxide solution. As shown in FIG. 6, the needle-shaped non-magnetic metal 4 protrudes from the surface of the anodic oxide film 3, and two-dimensional minute irregularities are formed on the substrate surface.
ついで、このようにして得られた磁気ディスク基板上に
、スパッタ、メンキなとの周知方法により磁性薄膜から
なる磁気記録層を形成することによって、磁気ディスク
が得られる。Next, a magnetic recording layer made of a magnetic thin film is formed on the thus obtained magnetic disk substrate by a well-known method such as sputtering or coating, thereby obtaining a magnetic disk.
このようにして製造された磁気ディスクにあっては、表
面の磁気記録層が下地の微小凹凸によって、同様の微小
凹凸を有するものになるため、磁気ヘッドと磁気ディス
クとの吸着が発生せず、摺動特性が良好で、コンタクト
スタート・ストップ(CSS)特性も秀れたものとなる
利点がある。In the magnetic disk manufactured in this way, the magnetic recording layer on the surface has the same minute unevenness as the underlying minute unevenness, so the magnetic head and the magnetic disk do not attract each other. It has the advantage of good sliding properties and excellent contact start/stop (CSS) properties.
ところが、この製法においては、基板をなすアルミニウ
ムやアルミニウム合金中には、その製造の際に、不可避
的に微量の異物や析出物が混在し、これら異物や析出物
が基板表面に存在すると、これがそのまま陽極酸化被膜
中に残り、これが第7図に示すように磁気ディスク基板
表面に突起状物5として表れることになる。このため、
針状の非磁性金属4による微小凹凸表面の均一性が乱さ
れ、磁気ヘッドの安定浮上を妨げる欠点がある。そしテ
、前記異物や析出物は、アルミニウムやアルミニウム合
金中のンリコン単体、酸化ケイ素、Mg25 i、 A
11sFe3などであることが判明した。However, in this manufacturing method, trace amounts of foreign matter and precipitates are unavoidably mixed into the aluminum or aluminum alloy that makes up the substrate, and when these foreign matter and precipitates are present on the surface of the substrate, this can cause problems. The particles remain in the anodic oxide film as they are, and appear as protrusions 5 on the surface of the magnetic disk substrate, as shown in FIG. For this reason,
This has the disadvantage that the uniformity of the surface of minute irregularities due to the needle-shaped non-magnetic metal 4 is disturbed, which hinders stable flying of the magnetic head. The foreign substances and precipitates include phosphorus alone in aluminum and aluminum alloys, silicon oxide, Mg25i, A
It turned out to be 11sFe3.
よって、この発明での課題は、磁気ディスク基板表面に
表れる析出物や異物を取り除き、突起状物の生成を防止
し、微小凹凸を乱す大きな突起が存在しない磁気ディス
ク基板を得ることのできる製法を提供することにある。Therefore, the object of this invention is to develop a manufacturing method that can remove precipitates and foreign matter appearing on the surface of a magnetic disk substrate, prevent the formation of protrusions, and obtain a magnetic disk substrate free of large protrusions that disturb minute irregularities. It is about providing.
かかる課題は、非磁性金属充填後のアルミニウム陽極酸
化被膜のエツチングをフッ酸液またはフッ酸、硝酸混液
を用いて行うことで解決される。This problem can be solved by etching the aluminum anodic oxide film after filling with the nonmagnetic metal using a hydrofluoric acid solution or a mixed solution of hydrofluoric acid and nitric acid.
以下、この発明の詳細な説明する。The present invention will be explained in detail below.
この発明の製法における基板としては、純アルミニ’7
A、4Mg−96ACなどのアルミニウム合金などから
なるものが用いられる。The substrate used in the manufacturing method of this invention is pure aluminum '7
A material made of aluminum alloy such as A, 4Mg-96AC, etc. is used.
この基板の表面は、まず周知方法によって陽極酸化処理
が施され、アルミニウム陽極酸化被膜が形成される。つ
いで、このアルミニウム陽極酸化被膜の微細孔に、銅、
スズ、亜鉛などの非磁性金属を充填する。この充填には
、これら金属の塩溶液を電解浴とする電解メツキ処理に
よって行われる。The surface of this substrate is first subjected to anodic oxidation treatment by a well-known method to form an aluminum anodic oxide film. Next, copper,
Filled with non-magnetic metals such as tin and zinc. This filling is performed by electrolytic plating using a salt solution of these metals as an electrolytic bath.
ついで、この非磁性金属が充填されたアルミニウム陽極
酸化被膜は、その表面全面をアルミナ砥粒などを用いて
研磨して、第1図に示すような基板を得る。第1図にお
いて、符号11は基板、12はアルミニウム陽極酸化被
膜、13は微細孔、14は非磁性金属である。また、符
号15は、アルミニウム陽極酸化被膜12に残る異物ま
たは析出物である。Next, the entire surface of the aluminum anodic oxide film filled with the nonmagnetic metal is polished using alumina abrasive grains or the like to obtain a substrate as shown in FIG. In FIG. 1, reference numeral 11 is a substrate, 12 is an aluminum anodic oxide film, 13 is a fine hole, and 14 is a nonmagnetic metal. Further, reference numeral 15 indicates foreign matter or precipitates remaining on the aluminum anodic oxide film 12.
次に、この状態の基板表面を、フッ酸単独あるいはフッ
酸と硝酸との混合液からなるエッチャントを用いてエツ
チング処理する。このエッチャント中のフッ酸の濃度は
0.05〜5重量%程度が好ましく、具体的には、前記
エッチャントに基板を常昌で10〜100秒間程浸漬す
る方法が用いられる。このエッチャントによる工、チン
グでは、そのエツチング速度が、銅などの非磁性金属1
4よりもアルマイト陽極酸化被膜12をなす酸化アルミ
ニウムが太き(、この酸化アルミニウムよりも異物また
は析出物15をなすンリコン単体、酸化ケイ素、Mg+
Siなとのケイ素系化合物かさらに大きくなる。このた
め、基板11表面の異物または析出物15か一番早く溶
解され、ついてアルマイト陽極酸化被膜12か溶解され
、非磁性金属14は少ししか溶解されないことになる。Next, the surface of the substrate in this state is etched using an etchant consisting of hydrofluoric acid alone or a mixture of hydrofluoric acid and nitric acid. The concentration of hydrofluoric acid in this etchant is preferably about 0.05 to 5% by weight, and specifically, a method is used in which the substrate is immersed in the etchant for about 10 to 100 seconds at a constant pressure. In etching using this etchant, the etching speed is higher than that of non-magnetic metals such as copper.
4, the aluminum oxide forming the alumite anodic oxide film 12 is thicker than the aluminum oxide (Aluminum oxide alone, silicon oxide, Mg+ forming the foreign matter or precipitate 15
Silicon-based compounds such as Si are even larger. Therefore, the foreign matter or precipitate 15 on the surface of the substrate 11 is dissolved first, followed by the alumite anodic oxide film 12, and the non-magnetic metal 14 is only slightly dissolved.
よって、このエッチャントによるエツチング処理では、
第2図に示すように、表面に残存する析出物や異物15
はその大部分が溶解除去され、アルマイト陽極酸化被膜
12かわずかに、例えば10〜5゜nm程度溶解除去さ
れ、非磁性金属14はほとんど溶解されず、針状にアル
マイト陽極酸化被膜12から突出した法帖で残り、これ
によって微小凹凸か形成されるとともに析出物や異物1
5が除去された表面が得られる。また、エッチャント濃
度、時間、温度などの工、チング条件を調整することに
よって第3図に示すように析出物または異物15の一部
だけを溶解除去して突起にならない程度におさめること
ができる。Therefore, in the etching process using this etchant,
As shown in Figure 2, precipitates and foreign matter remaining on the surface 15
Most of it was dissolved and removed, and the alumite anodic oxide coating 12 was slightly dissolved and removed, for example, about 10 to 5 nm, and the non-magnetic metal 14 was hardly dissolved and protruded from the alumite anodic oxide coating 12 in the form of needles. It remains in the sand, which forms minute irregularities and also removes precipitates and foreign matter.
A surface with 5 removed is obtained. Further, by adjusting etching conditions such as etchant concentration, time, and temperature, it is possible to dissolve and remove only a portion of the precipitates or foreign matter 15 to the extent that they do not form protrusions, as shown in FIG.
また、この操作の際、析出物または異物15の大きさが
、アルミニウム陽極酸化被膜12の全厚さまたはそれ以
上に相当する場合は、析出物または異物15の全体を除
去すると、アルミニウム陽極1t1 化被膜の一部分に
、その下層のアルミニウム単体またはアルミニウム基合
金が露出するので、その部分の防食のため、クロメート
処理を行うことが好適である。In addition, during this operation, if the size of the precipitate or foreign material 15 corresponds to the total thickness of the aluminum anodic oxide film 12 or more, if the entire precipitate or foreign material 15 is removed, the aluminum anode 1t1 will be formed. Since the underlying aluminum or aluminum-based alloy is exposed in a portion of the coating, it is preferable to perform chromate treatment to prevent corrosion in that portion.
かくして、析出物や異物15が取り除かれた磁気ディス
ク基板は、常法によりその表面に磁気記録層が形成され
て磁気ディスクとされる。A magnetic recording layer is formed on the surface of the magnetic disk substrate from which the precipitates and foreign matter 15 have been removed by a conventional method to form a magnetic disk.
また、この発明では、フッ酸またはフッ酸、硝酸混液か
らなるエッチャントによる工・、チング処理の際、アル
ミニウム陽極酸化被膜12の工・ノチング量(厚さ)が
不足し、所望の微小凹凸が得られない場合には、アルマ
イト陽極酸化被膜12のみをエツチングするための従来
のリン酸・クロム酸混合液または水酸化ナトリウム水溶
液などを用いて別にエツチング処理することもできる。Furthermore, in this invention, when etching and etching the aluminum anodic oxide film 12 with an etchant consisting of hydrofluoric acid or a mixed solution of hydrofluoric acid and nitric acid, the amount of etching and notching (thickness) of the aluminum anodic oxide film 12 is insufficient, and the desired micro-irregularities cannot be obtained. If this is not possible, a separate etching treatment can be carried out using a conventional phosphoric acid/chromic acid mixed solution or sodium hydroxide aqueous solution for etching only the alumite anodic oxide film 12.
この場合の処理は、フッ酸またはフッ酸、硝酸混液によ
るエツチング処理の前工程でも後工程でもよい。In this case, the treatment may be a pre- or post-etching process using hydrofluoric acid or a mixed solution of hydrofluoric acid and nitric acid.
このような磁気ディスク基板の製法にあっては、析出物
や異物が完全に取り除かれ、微小凹凸面から突出する突
起がなくなり、磁気へ/ドの安定な浮上が確保される。In this method of manufacturing a magnetic disk substrate, precipitates and foreign matter are completely removed, there are no protrusions protruding from the micro-asperity surface, and stable floating of the magnetic disk is ensured.
以下、具体例を示して、作用効果を明確にする。Hereinafter, specific examples will be shown to clarify the effects.
(実施例)
4%Mg−96%AQ合金からなる基板を、4重量%の
蓚酸水溶液中で直流電圧50Vで陽極酸化処理を施し、
厚さ約8μmのアルミニウム陽極酸化被膜を形成した。(Example) A substrate made of a 4% Mg-96% AQ alloy was anodized in a 4% by weight oxalic acid aqueous solution at a DC voltage of 50 V,
An aluminum anodic oxide film with a thickness of about 8 μm was formed.
このアルミニウム陽極酸化被膜の微細孔を拡大処理し、
ざらにバリヤ層調整を行ったのち、硫酸銅水溶液中で電
解処理して、銅を微細孔中に充填した。By enlarging the micropores of this aluminum anodic oxide coating,
After rough adjustment of the barrier layer, electrolytic treatment was performed in an aqueous copper sulfate solution to fill the micropores with copper.
ついで、このものの表面をアルミナ砥粒を用いて研磨し
、アルミニウム陽極酸化被膜の厚さを約4μmとした。Then, the surface of this product was polished using alumina abrasive grains, so that the thickness of the aluminum anodic oxide film was about 4 μm.
次に、この研磨表面を、フッ酸と硝酸とを7:3の容量
比で混合した混酸を水で100倍に希釈したエッチャン
トを用意し、このエッチャントに前記基板を20°Cで
60秒間浸漬してエツチングを行った。Next, an etchant prepared by diluting a mixed acid of hydrofluoric acid and nitric acid at a volume ratio of 7:3 with water 100 times was prepared, and the substrate was immersed in this etchant for 60 seconds at 20°C. Then I did the etching.
このようにして得られた基板表面を走査型電子顕微鏡で
観察したところ、表面には針状の銅か約20nm突出し
て微小凹凸が形成されているとともに異物や析出物によ
る突起状物は溶解されてなくなっていた。When the surface of the substrate obtained in this manner was observed with a scanning electron microscope, it was found that microscopic unevenness was formed on the surface with copper needles protruding by approximately 20 nm, and protrusions caused by foreign matter and precipitates were not dissolved. It was gone.
この磁気ディスク基板の表面に、クロム200nm1コ
バルトーニッケル・クロム60 nm、カーボン30n
mを順次スパッタして成膜し、磁気ディスクとした。こ
の磁気ディスクの表面は、微小凹凸面から突出する大き
な突起は全く認められなかった。The surface of this magnetic disk substrate is coated with 200 nm of chromium, 60 nm of cobalt-nickel chromium, and 30 nm of carbon.
A magnetic disk was formed by successively sputtering m. On the surface of this magnetic disk, no large protrusions protruding from the finely uneven surface were observed.
(比較例)
実施例において、エッチャントとして5重量%リン酸と
2重量%クロム酸の混合液を用いる以外は同様にして、
基板表面のアルミニウム陽極酸化被膜に銅を約20nm
突出させて微小凹凸を形成した。(Comparative example) In the same manner as in the example except that a mixed solution of 5% by weight phosphoric acid and 2% by weight chromic acid was used as the etchant,
Approximately 20 nm of copper is applied to the aluminum anodic oxide film on the substrate surface.
It was made to protrude to form minute irregularities.
この基板の表面に、実施例と同様の成膜を施し、磁気デ
ィスクとした。A film similar to that in the example was formed on the surface of this substrate to obtain a magnetic disk.
この磁気ディスクの表面を同様に走査型電子顕微鏡で観
察したところ、微小凹凸以外に最大約100 nmの突
起か多数認められた。When the surface of this magnetic disk was similarly observed using a scanning electron microscope, many protrusions with a maximum diameter of about 100 nm were observed in addition to minute irregularities.
以上説明したように、この発明の磁気ディスク基板の製
法は、アルミニウド陽極酸化被膜の微細孔に非磁性金属
を充填したのち、このアルミニウム陽極酸化被膜をフッ
酸液またはフッ酸、硝酸混液を用いてエツチングするも
のであるのて、アルミニウムやアルミニウム合金に存在
する異物や晶析物が取り除かれ、突起状物の生成が防止
され、均一な微小凹凸が形成された磁気ディスク基板を
製造することかできる。As explained above, the method for manufacturing the magnetic disk substrate of the present invention involves filling the micropores of an aluminum anodic oxide film with a nonmagnetic metal, and then coating the aluminum anodic oxide film with a hydrofluoric acid solution or a mixture of hydrofluoric acid and nitric acid. Since it is an etching process, it removes foreign substances and crystallized substances present in aluminum and aluminum alloys, prevents the formation of protrusions, and makes it possible to manufacture magnetic disk substrates with uniform minute irregularities. .
第1図ないし第3図は、この発明の製法の例を工程順に
示した概略断面図、
第4図ないし第7図は、従来の製法を工程順に示した概
略断面図である。
・基板、
・・アルミニウム陽極酸化被膜、
3・・
・・微細孔、
4 ・・・
・・非磁性金属、
異物。1 to 3 are schematic sectional views showing an example of the manufacturing method of the present invention in the order of steps, and FIGS. 4 to 7 are schematic sectional views showing the conventional manufacturing method in the order of steps.・Substrate, ・・Aluminum anodic oxide film, 3・・・Minor pores, 4・・・Nonmagnetic metal, foreign matter.
Claims (1)
酸化被膜の微細孔中に非磁性金属を充填したのち、 この表面をフッ酸液またはフッ酸、硝酸混液を用いてエ
ッチングすることを特徴とする磁気ディスク基板の製法
。[Claims] After filling the micropores of the anodic oxide film of a substrate provided with an aluminum anodic oxide film with a nonmagnetic metal, the surface is etched using a hydrofluoric acid solution or a mixed solution of hydrofluoric acid and nitric acid. A method for manufacturing a magnetic disk substrate characterized by the following.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13676590A JPH0430325A (en) | 1990-05-25 | 1990-05-25 | Production of magnetic disk substrate |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13676590A JPH0430325A (en) | 1990-05-25 | 1990-05-25 | Production of magnetic disk substrate |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0430325A true JPH0430325A (en) | 1992-02-03 |
Family
ID=15182988
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP13676590A Pending JPH0430325A (en) | 1990-05-25 | 1990-05-25 | Production of magnetic disk substrate |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0430325A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5470636A (en) * | 1991-03-15 | 1995-11-28 | Yamaha Corporation | Magnetic recording medium and method of producing it |
CN113168848A (en) * | 2018-11-26 | 2021-07-23 | 株式会社Uacj | Aluminum alloy substrate for magnetic disk and method for producing same, and magnetic disk and method for producing same |
-
1990
- 1990-05-25 JP JP13676590A patent/JPH0430325A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5470636A (en) * | 1991-03-15 | 1995-11-28 | Yamaha Corporation | Magnetic recording medium and method of producing it |
CN113168848A (en) * | 2018-11-26 | 2021-07-23 | 株式会社Uacj | Aluminum alloy substrate for magnetic disk and method for producing same, and magnetic disk and method for producing same |
US11482251B2 (en) | 2018-11-26 | 2022-10-25 | Uacj Corporation | Aluminum alloy substrate for magnetic disk and method for manufacturing same, aluminum alloy base disk for magnetic disk and method for manufacturing same, and magnetic disk and method for manufacturing the same |
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