JP2001307452A - Glass spacer and information recording device using the same - Google Patents
Glass spacer and information recording device using the sameInfo
- Publication number
- JP2001307452A JP2001307452A JP2000125922A JP2000125922A JP2001307452A JP 2001307452 A JP2001307452 A JP 2001307452A JP 2000125922 A JP2000125922 A JP 2000125922A JP 2000125922 A JP2000125922 A JP 2000125922A JP 2001307452 A JP2001307452 A JP 2001307452A
- Authority
- JP
- Japan
- Prior art keywords
- substrate
- glass
- glass spacer
- spacer
- information recording
- 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
- Holding Or Fastening Of Disk On Rotational Shaft (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、情報記録媒体用
基板を回転軸に固定するためのリング状のガラススペー
サおよびそれを用いた情報記録装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ring-shaped glass spacer for fixing an information recording medium substrate to a rotating shaft, and an information recording apparatus using the same.
【０００２】[0002]
【従来の技術】近年の高度情報化の進展は目覚ましく、
情報記録装置には、記録容量の増大および書き込み読み
出しの高速化が要求され続けている。現在様々な情報記
録装置が存在するが、コンピュータの情報記録装置とし
ては、ハードディスクが一般的に用いられている。2. Description of the Related Art Recent advances in information technology have been remarkable,
Information recording apparatuses are continuously required to have an increased recording capacity and a higher writing / reading speed. Currently, various information recording devices exist, and a hard disk is generally used as an information recording device of a computer.
【０００３】ハードディスクにおいては、記録容量を増
やすために、情報記録媒体の記録密度を高め、また情報
記録媒体用基板（以下、単に「基板」という）を複数枚
用いるなどの手段が取られている。一方、情報記録の高
速化については、基板の回転数を高めまた高密度化によ
るシークタイムの短縮などの手段が取られている。In order to increase the recording capacity of the hard disk, measures have been taken to increase the recording density of the information recording medium and to use a plurality of substrates for the information recording medium (hereinafter simply referred to as "substrates"). . On the other hand, to increase the speed of information recording, measures such as increasing the number of rotations of the substrate and shortening the seek time by increasing the density have been taken.
【０００４】情報記録媒体の記録密度を高めるために
は、基板と磁気ヘッドの間隔を短くし、かつ一定に保つ
ことが必要である。また、情報記録の高速化による基板
の高速回転によってもこの間隔は一定でなければなら
ず、基板が安定して回転することは極めて重要である。
基板と磁気ヘッドの間隔が短くなれば、基板表面の凹凸
が問題となることは明らかである。この表面の凹凸に
は、基板自体の形状に限らず、基板に付着したパーティ
クルと呼ばれる異物の存在も含まれる。基板表面の凹凸
が大きい場合、磁気ヘッドが基板の凸部と接触してバウ
ンドし、基板と磁気ヘッドの間隔が一定に保たれず、記
録読み出しエラーの生じるおそれが高くなる。また、こ
のような接触が頻繁に起こると、磁気ヘッドや基板の凸
部が破損し、情報の記録読み出しができなくなる。In order to increase the recording density of an information recording medium, it is necessary to shorten the distance between the substrate and the magnetic head and keep it constant. This interval must be constant even when the substrate is rotated at a high speed due to an increase in the speed of information recording, and it is extremely important that the substrate rotate stably.
Obviously, if the distance between the substrate and the magnetic head becomes shorter, irregularities on the surface of the substrate become a problem. The irregularities on the surface include not only the shape of the substrate itself but also the presence of foreign matters called particles attached to the substrate. When the unevenness of the substrate surface is large, the magnetic head comes into contact with the convex portion of the substrate and bounces, and the distance between the substrate and the magnetic head is not kept constant. Also, if such contact frequently occurs, the magnetic head and the projections of the substrate will be damaged, making it impossible to record and read information.
【０００５】ハードディスクでは、ドーナツ型の基板を
回転軸に固定する必要があり、基板を両側から挟み込む
ようにリング状のスペーサが回転軸に差し込まれて存在
する。このスペーサは、基板を複数枚用いる場合、基板
間の距離を一定に保つ機能も果たす。そのため、スペー
サには、基板が安定して回転するように、熱や外力によ
って変形しない高い剛性が要求され、従来はステンレス
製のものが使用されてきた。In a hard disk, it is necessary to fix a donut-shaped substrate to a rotating shaft, and a ring-shaped spacer is inserted into the rotating shaft so as to sandwich the substrate from both sides. When a plurality of substrates are used, the spacer also functions to keep the distance between the substrates constant. Therefore, the spacer is required to have high rigidity so as not to be deformed by heat or external force so that the substrate rotates stably. Conventionally, a spacer made of stainless steel has been used.
【０００６】[0006]
【発明が解決しようとする課題】ところが、ステンレス
製のスペーサは、強度および剛性は高いが表面平滑度を
高めることが困難であった。これは、ステンレスは硬度
が高く表面が研削され難いためである。スペーサの表面
平滑度が低い場合、スペーサと基板あるいはスペーサと
回転軸の接触により異物が発生し易くなり、それが基板
に付着して記録読み出しの障害となる場合があった。However, the spacer made of stainless steel has high strength and rigidity, but it is difficult to increase the surface smoothness. This is because stainless steel has high hardness and its surface is hard to be ground. When the surface smoothness of the spacer is low, foreign matter is likely to be generated due to the contact between the spacer and the substrate or between the spacer and the rotating shaft, and the foreign matter may adhere to the substrate and hinder recording and reading.
【０００７】また、現在ハードディスクの基板には、加
工の容易さおよび表面平滑度の高さから、アルミニウム
またはガラス製のものが使用されている。ステンレス製
のスペーサはこれらの基板と熱膨張係数差が大きいた
め、基板回転時に発生する熱によりスペーサと基板の接
触面において応力が生じる。この応力が大きくなると、
スペーサと基板がずれ、基板の回転が不安定になり、情
報の記録読み出しが不安定になる。Further, at present, a substrate made of aluminum or glass is used for a substrate of a hard disk because of its easy processing and high surface smoothness. Since the spacer made of stainless steel has a large difference in thermal expansion coefficient from those of these substrates, stress is generated at the contact surface between the spacer and the substrate due to heat generated when the substrate rotates. When this stress increases,
The spacer and the substrate are displaced, the rotation of the substrate becomes unstable, and the recording and reading of information become unstable.
【０００８】さらに、基板の回転により生じる静電気が
基板表面に溜まると、磁気ヘッドに向かって放電が起き
記録読み出しエラーとなることが知られており、この静
電気を除去する必要がある。特に、最近では感度の良い
磁気抵抗型ヘッドが用いられるようになってきており、
この静電気除去の必要性はますます高まってきている。Further, it is known that, when static electricity generated by the rotation of the substrate accumulates on the substrate surface, a discharge is caused toward the magnetic head and a recording / reading error occurs, and it is necessary to remove the static electricity. In particular, recently, a highly sensitive magnetoresistive head has been used,
The need for this static elimination is increasing.
【０００９】この発明は、このような従来技術に存在す
る問題に着目してなされたものである。その目的とする
ところは、基板の回転による異物の発生を抑制するスペ
ーサ、すなわち表面平滑度が高くかつ加工し易いスペー
サを提供することにある。また、熱によっても基板との
接触面においてずれを生じ難いスペーサ、すなわち基板
と熱膨張係数差の小さいスペーサを提供することにあ
る。さらには、基板表面の静電気を除去するスペーサを
提供することにある。そして、これら特性を備えたガラ
ススペーサを用いた情報記録装置を提供することにあ
る。The present invention has been made by paying attention to such a problem existing in the prior art. An object of the present invention is to provide a spacer that suppresses generation of foreign matter due to rotation of a substrate, that is, a spacer that has high surface smoothness and is easy to process. Another object of the present invention is to provide a spacer that is unlikely to be displaced by heat even on the contact surface with the substrate, that is, a spacer having a small difference in thermal expansion coefficient from the substrate. Another object of the present invention is to provide a spacer for removing static electricity from the surface of the substrate. Another object of the present invention is to provide an information recording apparatus using a glass spacer having these characteristics.
【００１０】[0010]
【課題を解決するための手段】上記の目的を達成するた
めに、請求項１に記載の発明のガラススペーサは、基板
に接する部分の平均表面粗さが１μm以下であるもので
ある。In order to achieve the above object, the glass spacer according to the first aspect of the present invention has an average surface roughness of 1 μm or less at a portion in contact with the substrate.
【００１１】請求項２に記載の発明のガラススペーサ
は、基板に接する部分の平均表面粗さが０．００１〜
０．３μmであるものである。In the glass spacer according to the second aspect of the present invention, an average surface roughness of a portion in contact with the substrate is 0.001 to 0.001.
It is 0.3 μm.
【００１２】請求項３に記載の発明のガラススペーサ
は、請求項１または２に記載の発明において、基板に接
する部分の最大表面粗さが３μm以下であるものであ
る。According to a third aspect of the present invention, there is provided the glass spacer according to the first or second aspect, wherein a maximum surface roughness of a portion in contact with the substrate is 3 μm or less.
【００１３】請求項４に記載の発明のガラススペーサ
は、請求項１〜３のいずれか１項に記載の発明におい
て、基板との熱膨張係数の差が２×１０-6℃-1以下であ
るものである。According to a fourth aspect of the present invention, in the glass spacer according to any one of the first to third aspects, the difference in thermal expansion coefficient between the glass spacer and the substrate is 2 × 10 −6 ° C.- 1 or less. There is something.
【００１４】請求項５に記載の発明のガラススペーサ
は、請求項１〜４のいずれか１項に記載の発明におい
て、電気伝導率が１×１０7(Ω・m)-1以下であるもので
ある。A glass spacer according to a fifth aspect of the present invention is the glass spacer according to any one of the first to fourth aspects, wherein the electrical conductivity is 1 × 10 7 (Ω · m) -1 or less. It is.
【００１５】請求項６に記載の発明の情報記録装置は、
請求項１〜５のいずれか１項に記載のガラススペーサを
用いたものである。[0015] The information recording apparatus of the invention according to claim 6 is:
A glass spacer according to any one of claims 1 to 5 is used.
【００１６】[0016]
【発明の実施の形態】以下、この発明の実施形態につい
て詳細に説明する。ガラススペーサは、表面加工が比較
的容易で研磨後の表面平滑性が極めて高い。これは、ガ
ラスが非結晶性物質であるため、結晶単位で研削される
ことがないからである。なお、ガラスには結晶化ガラス
が含まれる。結晶化ガラスは、ガラス全体が結晶化した
ものではなく、結晶性を帯びた原子団が散在するもので
ある。そのため、通常のガラスほどではないが、ステン
レスに比べれば研磨が容易で表面平滑性も高い。したが
って、結晶化ガラスであっても通常のガラスに近似する
効果が発揮される。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. The surface processing of the glass spacer is relatively easy, and the surface smoothness after polishing is extremely high. This is because glass is an amorphous substance and is not ground in crystal units. Note that the glass includes crystallized glass. Crystallized glass is not crystallized glass as a whole, but is one in which atomic groups with crystallinity are scattered. Therefore, although not as good as ordinary glass, it is easier to polish and has higher surface smoothness than stainless steel. Therefore, even in the case of crystallized glass, an effect similar to that of ordinary glass is exhibited.
【００１７】ガラススペーサは、基板を回転軸に固定連
結するため、基板を挟み込むようにして密着する。基板
を複数枚使用する情報記録装置においては、ガラススペ
ーサ１１は、図２に示すように基板１０と交互に回転軸
に挿入され、基板間の間隙を確保する機能を果たす。ガ
ラススペーサは基板と密着し摩擦力によって基板を固定
するので、その表面平滑度が高いほど、接触面積が大き
くなり摩擦力も大きくなる。一方、表面平滑度が低いす
なわち表面の凹凸が大きいと、凸部に大きな負荷が掛か
り、凸部が破損し、それが異物として基板表面に付着し
易くなる。そのため、ガラススペーサの表面平滑度は、
一定の範囲に制御されることが好ましく、具体的には基
板に接する部分の平均表面粗さ（以下「Ｒａ」とする）
が１μm以下であることが好ましい。これは、本発明者
らの行った多くの実験の結果から明らかになった好適範
囲である。ここで、Ｒａとは、原子間力顕微鏡（ＡＦ
Ｍ）により算出される値であって、任意の２５μm□に
おける表面凹凸の平均値をいう。また、Ｒａが１μmを
越えると、ガラススペーサ表面に研磨剤が残存し易くな
ることも確認されている。The glass spacer is tightly connected to the rotating shaft so as to sandwich the substrate therebetween. In an information recording apparatus using a plurality of substrates, the glass spacers 11 are alternately inserted into the rotating shaft with the substrates 10 as shown in FIG. Since the glass spacer is in close contact with the substrate and fixes the substrate by the frictional force, the higher the surface smoothness, the larger the contact area and the greater the frictional force. On the other hand, if the surface smoothness is low, that is, if the unevenness of the surface is large, a large load is applied to the convex portion, and the convex portion is damaged, and this easily adheres to the substrate surface as foreign matter. Therefore, the surface smoothness of the glass spacer is
It is preferable that the surface is controlled within a certain range. Specifically, the average surface roughness of a portion in contact with the substrate (hereinafter referred to as “Ra”)
Is preferably 1 μm or less. This is a preferable range that has become clear from the results of many experiments performed by the present inventors. Here, Ra is an atomic force microscope (AF)
M), which means the average value of surface irregularities at an arbitrary 25 μm square. It has also been confirmed that when Ra exceeds 1 μm, the abrasive tends to remain on the surface of the glass spacer.
【００１８】さらに、ガラススペーサの基板に接する部
分のＲａは、０．００１〜０．３μmであることが好ま
しい。Ｒａが０．３μmより大きい場合は、ガラススペ
ーサの電気伝導率が下記目標値に達し難くなり、またガ
ラススペーサの温度が６０℃以上になると異物の発生率
が高くなることが確認されている。一方、Ｒａが０．０
０１μmより小さい場合は、異物の発生は抑えられる
が、研磨コストが高くなり実用的でなくなる。したがっ
て、Ｒａの下限値は０．００１μmが適当である。Further, Ra of the portion of the glass spacer in contact with the substrate is preferably 0.001 to 0.3 μm. It has been confirmed that when Ra is larger than 0.3 μm, the electrical conductivity of the glass spacer hardly reaches the target value described below, and when the temperature of the glass spacer becomes 60 ° C. or higher, the generation rate of foreign matters increases. On the other hand, Ra is 0.0
When the diameter is smaller than 01 μm, the generation of foreign matter can be suppressed, but the polishing cost becomes high, and it is not practical. Therefore, the lower limit of Ra is suitably 0.001 μm.
【００１９】上記異物の発生は、ガラススペーサの最大
表面粗さ（以下「Ｒmax」とする）の問題として把握す
ることもできる。ここで、ＲmaxとはＡＦＭにより算出
される値であって、任意の２５μm□における平均基準
線からの凹凸の最大値をいう。ガラススペーサの基板に
接する部分のＲmaxは、３μm以下であることが好まし
い。このＲmaxの好適範囲は、本発明者らの多くの実験
の結果初めて明らかになったものである。The generation of the foreign matter can be understood as a problem of the maximum surface roughness (hereinafter referred to as "Rmax") of the glass spacer. Here, Rmax is a value calculated by AFM, and refers to the maximum value of unevenness from an average reference line at an arbitrary 25 μm square. Rmax of the portion of the glass spacer in contact with the substrate is preferably 3 μm or less. This preferred range of Rmax was first clarified as a result of many experiments by the present inventors.
【００２０】ハードディスクでは、回転軸の回転に伴い
熱が発生し、この熱を受けてガラススペーサおよび基板
が熱膨張する。ガラススペーサと基板の熱膨張の差が大
きい場合、ガラススペーサと基板の接触面に大きな応力
が発生する。そして、ガラススペーサと基板の接触面に
おける摩擦力がこの応力に耐えられなくなると、ガラス
スペーサと基板表面の相対位置にずれが生じる。したが
って、ガラススペーサと基板の熱膨張係数が近いか、ま
たこれらの使用温度が低く抑えられれば、このようなず
れの発生は抑えられる。しかし、記録読み出し速度の向
上のため、基板の回転速度がさらに高くなることは必至
であり、ガラススペーサの使用温度は現状以上に高くな
ると予想される。そこで、今後要求される性能をも充た
すために、ガラススペーサと熱膨張差の小さな基板を選
択することが好ましい。具体的には、ガラススペーサと
同じ組成のガラスからなる基板が最適である。なお、ガ
ラスの熱膨張係数は、ソーダライムガラスが９．９×１
０-6℃-1、アルミノシリケートガラスが４．３×１０-6
℃-1であり（ガラスの事典第３６７頁 １９８５年朝倉
書店発行）、一方ステンレスは９．０〜１７．３×１０
-6℃-1（改訂２版金属データブック第１１６頁 昭和５
９年 丸善株式会社発行）である。ガラススペーサは、
ステンレスのスペーサに比べ熱膨張係数が小さいため、
熱膨張に関する問題は起こり難い。ハードディスクにお
いては、通常の使用温度が０〜６０℃程度であるから、
ガラススペーサと基板との熱膨張係数の差が２×１０-6
℃-1以下であれば、熱膨張差が１．２μm／mm以下とな
り、実質上問題がなくなる。In the hard disk, heat is generated as the rotating shaft rotates, and the heat causes the glass spacer and the substrate to thermally expand. When the difference in thermal expansion between the glass spacer and the substrate is large, a large stress is generated on the contact surface between the glass spacer and the substrate. Then, when the frictional force at the contact surface between the glass spacer and the substrate cannot withstand this stress, the relative position between the glass spacer and the substrate surface shifts. Therefore, if the thermal expansion coefficients of the glass spacer and the substrate are close to each other, and if the operating temperatures thereof are kept low, occurrence of such a shift can be suppressed. However, in order to improve the recording / reading speed, it is inevitable that the rotation speed of the substrate will be further increased, and the use temperature of the glass spacer is expected to be higher than the current state. Therefore, in order to satisfy the performance required in the future, it is preferable to select a substrate having a small thermal expansion difference from the glass spacer. Specifically, a substrate made of glass having the same composition as the glass spacer is optimal. The thermal expansion coefficient of the glass was 9.9 × 1 for soda-lime glass.
0 -6 ° C -1 , 4.3 × 10 -6 aluminosilicate glass
° C- 1 (Glass Encyclopedia, p. 367, published by Asakura Shoten, 1985), whereas stainless steel is 9.0-17.3 × 10
-6 ℃ -1 (Revised 2nd edition Metal Data Book p.116 Showa 5
9 years, published by Maruzen Co., Ltd.). The glass spacer is
Because the thermal expansion coefficient is smaller than stainless steel spacers,
Problems with thermal expansion are unlikely. In a hard disk, since the normal use temperature is about 0 to 60 ° C,
The difference in the coefficient of thermal expansion between the glass spacer and the substrate is 2 × 10 -6
If the temperature is lower than -1 ° C., the difference in thermal expansion becomes 1.2 μm / mm or less, and there is practically no problem.
【００２１】ステンレス製のスペーサは導電性が高いた
め上述の静電気は問題とならなかったが、ガラススペー
サは絶縁体であるので、これを用いたハードディスクで
は静電気が基板上に溜まり易い。したがって、静電気を
除去するため、ガラススペーサに電気伝導性を付与する
必要がある。その手段としては、浸漬法、蒸着法または
スパッタリング法などによりガラススペーサの表面に金
属膜を設ける手段、またガラススペーサの組成中にイオ
ン伝導率を高める鉄分などの成分を多く含ませる手段な
どがある。この電気伝導率は、１×１０7(Ω・m)-1以上
であることが好ましい。電気導電率が１×１０7(Ω・m)
-1より小さい場合は、基板表面に静電気が残留し易くな
り、磁気ヘッドへの放電による記録読み出しエラーの生
じるおそれが高くなる。Since the spacer made of stainless steel has high conductivity, the above-mentioned static electricity is not a problem. However, since the glass spacer is an insulator, the static electricity easily accumulates on the substrate in a hard disk using the spacer. Therefore, in order to remove static electricity, it is necessary to impart electric conductivity to the glass spacer. As the means, there is a means for providing a metal film on the surface of the glass spacer by an immersion method, an evaporation method, a sputtering method, or the like, or a means for increasing a component such as iron which increases ionic conductivity in the composition of the glass spacer. . This electric conductivity is preferably 1 × 10 7 (Ω · m) −1 or more. Electric conductivity is 1 × 10 7 (Ω · m)
If it is smaller than -1 , static electricity tends to remain on the substrate surface, and the possibility of occurrence of a recording / reading error due to discharge to the magnetic head increases.
【００２２】ガラススペーサの材質は、特に限定される
ものではなく、アルミノシリケートガラス、ソーダライ
ムガラス、ソーダアルミノケイ酸ガラス、アルミノボロ
ンシリケートガラス、ボロンシリケートガラス、石英ガ
ラスまたは結晶化ガラスなどが挙げられる。アルミノシ
リケートガラスは、二酸化ケイ素（SiO2）：５９〜６３
重量％、酸化アルミニウム（Al2O3）：５〜１６重量
％、酸化リチウム（Li2O）：２〜１０重量％、酸化ナト
リウム（Na2O）：２〜１２重量％、酸化ジルコニウム
（ZrO2）：０〜５重量％を主成分とするガラスである。
このガラスは、剛性が高く、熱膨張係数が低い点で、ガ
ラススペーサに好適である。ソーダライムガラスは、Si
O2：６５〜７５重量％、Al2O3：１〜６重量％、CaO：２
〜７重量％、Na2O：５〜１７重量％、ZrO2：０〜５重量
％を主成分とするガラスである。このガラスは、比較的
柔らかく研磨が容易であるので、表面平滑度を高め易い
点で、ガラススペーサに適している。The material of the glass spacer is not particularly limited, and examples thereof include aluminosilicate glass, soda lime glass, sodaaluminosilicate glass, aluminoborosilicate glass, boron silicate glass, quartz glass and crystallized glass. Aluminosilicate glass, silicon dioxide (SiO 2): 59~63
% By weight, aluminum oxide (Al 2 O 3 ): 5 to 16% by weight, lithium oxide (Li 2 O): 2 to 10% by weight, sodium oxide (Na 2 O): 2 to 12% by weight, zirconium oxide (ZrO) 2 ): A glass mainly containing 0 to 5% by weight.
This glass is suitable for a glass spacer because of its high rigidity and low coefficient of thermal expansion. Soda lime glass is Si
O 2 : 65 to 75% by weight, Al 2 O 3 : 1 to 6% by weight, CaO: 2
7 wt%, Na 2 O: 5~17 wt%, ZrO 2: is a glass composed mainly of 0-5 wt%. Since this glass is relatively soft and easy to polish, it is suitable for a glass spacer in that the surface smoothness is easily increased.
【００２３】ガラススペーサは、フロート法やダウンロ
ード法などにより製造した板状ガラスをドーナツ状に切
り出したもの、プレス法で熔融ガラスを成型したもの、
管引き法で製造したガラス管を適当な長さにスライスし
たものなどいずれの方法によるものでもよい。このよう
に成形されたガラススペーサは、少なくとも基板と接す
る部分を研磨される。研磨の方法は、特に限定されるも
のではなく、ガラスの基板の研磨方法がそのまま利用可
能である。具体的には、ガラススペーサの内径面と外径
面を粗研磨し、つづいて基板と接する部分を粗研磨およ
び精密研磨する方法である。The glass spacer is obtained by cutting a plate-like glass manufactured by a float method, a download method, or the like into a donut shape, by molding a molten glass by a press method,
Any method may be used, such as a glass tube produced by a tube drawing method sliced to an appropriate length. The glass spacer formed in this manner is polished at least at a portion in contact with the substrate. The polishing method is not particularly limited, and a polishing method for a glass substrate can be used as it is. Specifically, this method is a method in which the inner and outer diameter surfaces of the glass spacer are roughly polished, and then the portion in contact with the substrate is roughly and precisely polished.
【００２４】ガラススペーサは情報記録装置の組立時に
押圧されて基板と密着し、ガラススペーサと基板との間
には接着剤は不要である。これは、接着剤には有機性の
ものが多く、熱や酸化により接着剤自体が劣化し異物発
生の原因となるおそれがあるからである。しかし、ガラ
ススペーサを用いる場合は、熱や酸化に強くまた接着強
度の高いシラン系無機接着剤の利用が可能となる。そこ
で、シラン系無機接着剤をガラススペーサと基板の間に
介在させてもよい。The glass spacer is pressed during the assembly of the information recording apparatus and comes into close contact with the substrate, and no adhesive is required between the glass spacer and the substrate. This is because many adhesives are organic, and the adhesive itself may be degraded by heat or oxidation, which may cause generation of foreign substances. However, when a glass spacer is used, a silane-based inorganic adhesive that is resistant to heat and oxidation and has high adhesive strength can be used. Therefore, a silane-based inorganic adhesive may be interposed between the glass spacer and the substrate.
【００２５】[0025]
【実施例】以下、実施例および比較例によりこの発明を
さらに具体的に説明する。 （実施例１） １．ガラススペーサ成形工程 フロート法で製造された厚さ２．１mmの板状アルミノシ
リケートガラスを、内径１９mm、外径２３mmに切り出
し、これを化学強化した。このアルミノシリケートガラ
スの組成比（酸化物換算）は、SiO2：６０重量％、Al2O
3：１２重量％、Li2O：５重量％、Na2O：８重量％、ZrO
2：２重量％、その他１３重量％であった。The present invention will be more specifically described below with reference to examples and comparative examples. (Example 1) 1. Glass Spacer Forming Step A plate-shaped aluminosilicate glass having a thickness of 2.1 mm manufactured by a float method was cut into an inner diameter of 19 mm and an outer diameter of 23 mm, and this was chemically strengthened. The composition ratio (in terms of oxide) of this aluminosilicate glass is SiO 2 : 60% by weight, Al 2 O
3 : 12% by weight, Li 2 O: 5% by weight, Na 2 O: 8% by weight, ZrO
2 : 2% by weight, other 13% by weight.
【００２６】２．研磨工程 ダイヤモンドを座金に電着したダイヤモンド砥石（＃５
００）を用いて上記ガラススペーサの内径面および外径
面を、内径２０mm、外径２２mmまで研磨した。このと
き、ガラススペーサの内周面および外周面のＲmaxは共
に１２μmであった。つぎに、酸化セリウムを含有した
研磨砥石で、外周面および内周面を所定量面取り加工し
た。そして、ガラススペーサの上下面（基板に接する部
分）を両面研磨のラッピング装置を用いて粒度＃１００
０のアルミナ砥粒で厚さ２mmになるまで研磨した。この
段階でガラススペーサの上下面のＲmaxは共に２μmであ
った。つづいて、スラリーを使用してブラシ研磨によ
り、ガラススペーサを回転させながら内径面および外径
面を２０分間で２０μmずつ研磨した。その後、ガラス
スペーサの上下面に残っている傷や歪みを除去するため
仕上げ研磨を行った。仕上げ研磨の条件は、以下の通り
である。2. Polishing process Diamond whetstone electrodeposited with diamond on washer (# 5
00), the inner and outer diameter surfaces of the glass spacer were polished to an inner diameter of 20 mm and an outer diameter of 22 mm. At this time, Rmax of both the inner and outer peripheral surfaces of the glass spacer was 12 μm. Next, the outer peripheral surface and the inner peripheral surface were chamfered by a predetermined amount using a polishing grindstone containing cerium oxide. Then, the upper and lower surfaces of the glass spacer (parts in contact with the substrate) are ground to a grain size of # 100
Polishing was performed with alumina abrasive grains of 0 until the thickness became 2 mm. At this stage, both the Rmax of the upper and lower surfaces of the glass spacer were 2 μm. Subsequently, the inner diameter surface and the outer diameter surface were polished by brush polishing using the slurry at an interval of 20 μm for 20 minutes while rotating the glass spacer. Thereafter, finish polishing was performed to remove scratches and distortion remaining on the upper and lower surfaces of the glass spacer. The conditions of the final polishing are as follows.
【００２７】 研磨液 ： 酸化セリウム水溶液（平均粒径１μ
m） 研磨布 ： 軟質ポリッシャ（ポリラックス） 下定盤回転数 ： ５０r.p.m 研磨加重 ： １００g/cm2 研磨時間 ： ２０分間 研磨量 ： ２０μmPolishing liquid: cerium oxide aqueous solution (average particle size 1 μm)
m) Polishing cloth: Soft polisher (Porelax) Lower platen rotation speed: 50 rpm Polishing load: 100 g / cm 2 Polishing time: 20 minutes Polishing amount: 20 μm
【００２８】仕上げ研磨後、ガラススペーサを中性洗
剤、純水、イソプロピルアルコール（ＩＰＡ）およびＩ
ＰＡ蒸気乾燥槽に順次浸漬して洗浄した。After the final polishing, the glass spacer is replaced with a neutral detergent, pure water, isopropyl alcohol (IPA) and I
It was immersed in a PA steam drying tank and washed.
【００２９】３．化学強化工程 ガラススペーサを端面保持可能なホルダーに入れ、４０
０℃に加熱した硝酸カリウム（６０％）と硝酸ナトリウ
ム（４０％）の混合溶液に３時間浸漬した。その後、ガ
ラススペーサを中性洗剤、純水、ＩＰＡおよびＩＰＡ蒸
気乾燥の洗浄槽に順次浸漬して洗浄した。3. Chemical strengthening process Put the glass spacer into a holder that can hold
It was immersed in a mixed solution of potassium nitrate (60%) and sodium nitrate (40%) heated to 0 ° C. for 3 hours. Thereafter, the glass spacers were sequentially immersed in a washing bath of a neutral detergent, pure water, IPA and IPA vapor drying for washing.
【００３０】化学強化後、ガラススペーサの表面平滑度
を測定したところ、 上面および下面 ： Ｒａ＝０．００１〜０．００５μ
m、 Ｒmax＝０．００７〜０．０４μm 内径面 ： Ｒａ＝０．１μm Ｒmax＝０．８９μm 外径面 ： Ｒａ＝０．１７μm Ｒmax＝１．２μmAfter the chemical strengthening, the surface smoothness of the glass spacer was measured. The upper surface and the lower surface: Ra = 0.001 to 0.005 μm
m, Rmax = 0.007-0.04 μm Inner diameter surface: Ra = 0.1 μm Rmax = 0.89 μm Outer diameter surface: Ra = 0.17 μm Rmax = 1.2 μm
【００３１】このガラススペーサの表面を光学顕微鏡で
精査したところ、異物の存在は認められなかった。Examination of the surface of the glass spacer with an optical microscope revealed that no foreign matter was present.
【００３２】４．導電性付与工程 スパッタリング法により、ガラススペーサ表面にクロム
(Cr)膜を２０nm成膜した。このガラススペーサの電気伝
導率を測定したところ、２×１０6(Ω・m)-1であった。4. Conductivity-imparting process Chromium on the glass spacer surface by sputtering
A (Cr) film was formed to a thickness of 20 nm. The measured electrical conductivity of the glass spacer was 2 × 10 6 (Ω · m) −1 .
【００３３】５．ガラススペーサの性能評価 このガラススペーサを同じ組成のアルミノシリケートガ
ラスの基板と共に、定法にしたがいハードディスクに組
み込んだ。ハードディスクのフライングハイトを１５nm
に設定して、２４時間連続シークテストを行ったとこ
ろ、ハードディスクの内部温度は６０℃にまで上昇した
が、磁気ヘッドと基板の接触および記録読み出しエラー
は生じなかった。このテストの後、ガラススペーサと基
板とのずれの発生を調査したが、ずれの生じた跡は確認
できなかった。また、基板の表面を精査したが、異物の
存在は確認できなかった。上記の製造条件および評価結
果を下記「表１」に示す。5. Performance Evaluation of Glass Spacer The glass spacer was mounted on a hard disk together with a substrate of aluminosilicate glass having the same composition according to a standard method. 15nm hard disk flying height
And a continuous 24-hour seek test, the internal temperature of the hard disk rose to 60 ° C., but no contact between the magnetic head and the substrate and no recording / reading error occurred. After this test, the occurrence of a displacement between the glass spacer and the substrate was examined, but no trace of the displacement could be confirmed. Further, although the surface of the substrate was closely examined, the presence of foreign matter could not be confirmed. The above manufacturing conditions and evaluation results are shown in Table 1 below.
【００３４】（実施例２） １．ガラススペーサ成形工程 外径２２mm、内径２０mmのソーダライムガラスのガラス
管をスライシングマシーンで厚さ２．１mmにスライスし
た。このソーダライムガラスの酸化物換算の組成比は、
SiO2：７０重量％、Al2O3：５重量％、CaO：７重量％、
Na2O：１５重量％、ZrO2：２重量％、その他：１重量％
である。(Embodiment 2) Glass Spacer Forming Step A glass tube of soda lime glass having an outer diameter of 22 mm and an inner diameter of 20 mm was sliced with a slicing machine to a thickness of 2.1 mm. The composition ratio of this soda lime glass in terms of oxide is
SiO 2 : 70% by weight, Al 2 O 3 : 5% by weight, CaO: 7% by weight,
Na 2 O: 15% by weight, ZrO 2 : 2% by weight, others: 1% by weight
It is.
【００３５】２．研磨工程 実施例１と同様である。2. Polishing Step Same as in the first embodiment.
【００３６】３．化学強化工程 硝酸カリウム（６０％）と硝酸ナトリウム（４０％）の
混合溶液の温度を４３０℃にした以外は、実施例１と同
様にして化学強化を行った。3. Chemical strengthening step Chemical strengthening was performed in the same manner as in Example 1 except that the temperature of the mixed solution of potassium nitrate (60%) and sodium nitrate (40%) was 430 ° C.
【００３７】化学強化後、ガラススペーサの表面平滑度
を測定したところ、以下の通りであった。 上面および下面 ： Ｒａ＝０．００１〜０．００５μ
m、 Ｒmax＝０．００７〜０．０４５μm 内径面 ： Ｒａ＝０．０５μm Ｒmax＝０．５６μm 外径面 ： Ｒａ＝０．０９μm Ｒmax＝０．９５μmAfter the chemical strengthening, the surface smoothness of the glass spacer was measured. Upper and lower surfaces: Ra = 0.001 to 0.005μ
m, Rmax = 0.007-0.045 μm Inner diameter surface: Ra = 0.05 μm Rmax = 0.56 μm Outer diameter surface: Ra = 0.09 μm Rmax = 0.95 μm
【００３８】このガラススペーサの表面を光学顕微鏡で
精査したところ、異物の存在は認められなかった。Examination of the surface of the glass spacer with an optical microscope revealed that no foreign matter was present.
【００３９】４．導電性付与工程 実施例１と同様にして、２×１０6(Ω・m)-1のCr膜を成
膜した。4. Conductivity imparting step In the same manner as in Example 1, a Cr film of 2 × 10 6 (Ω · m) −1 was formed.
【００４０】５．ガラススペーサの性能評価 実施例１と同様にして、その性能を評価した。その結果
を下記「表１」に示す。5. Performance evaluation of glass spacer The performance was evaluated in the same manner as in Example 1. The results are shown in Table 1 below.
【００４１】（比較例１）実施例１において、２．研磨
工程の仕上げ研磨を行わず、また４．伝導性付与工程の
Cr膜の成膜を行わない以外は同様にして、ガラススペー
サを製造した。化学強化後のガラススペーサの表面平滑
度は、以下の通りであった。(Comparative Example 1) 3. Finish polishing is not performed in the polishing step. Of the conductivity imparting process
A glass spacer was manufactured in the same manner except that the Cr film was not formed. The surface smoothness of the glass spacer after the chemical strengthening was as follows.
【００４２】 上面および下面 ： Ｒａ＝１〜２μm、 Ｒmax＝３〜５μm 内径面 ： Ｒａ＝０．１μm Ｒmax＝０．８９μm 外径面 ： Ｒａ＝０．１７μm Ｒmax＝１．２μmUpper and lower surfaces: Ra = 1 to 2 μm, Rmax = 3 to 5 μm Inner diameter surface: Ra = 0.1 μm Rmax = 0.89 μm Outer diameter surface: Ra = 0.17 μm Rmax = 1.2 μm
【００４３】化学強化後、ガラススペーサの表面を光学
顕微鏡で観察したところ、凸部に引っ掛かるように研磨
剤が残存していた。また、シークテストでは、磁気ヘッ
ドへの放電によると思われる記録読み出しエラーが確認
され、また開始後１時間で磁気ヘッドが基板に接触した
ため、テストを中止した。シークテスト後の基板表面を
光学顕微鏡で精査したところ、ガラススペーサとの接触
面付近に２〜４μm径の異物が散見された。これらの結
果を、下記「表１」に併せて示す。After the chemical strengthening, the surface of the glass spacer was observed with an optical microscope. As a result, the abrasive remained so as to be caught on the projection. Further, in the seek test, a recording / reading error considered to be caused by discharge to the magnetic head was confirmed, and the test was stopped because the magnetic head contacted the substrate one hour after the start. When the substrate surface after the seek test was closely examined with an optical microscope, foreign matters having a diameter of 2 to 4 μm were found near the contact surface with the glass spacer. These results are shown in Table 1 below.
【００４４】[0044]
【表１】 [Table 1]
【００４５】[0045]
【発明の効果】この発明は、以上のように構成されてい
るので、つぎのような効果を奏する。請求項１に記載の
発明によれば、基板に接する部分の平均表面粗さが１μ
m以下であるので、基板とのずれが生じ難く、かつ異物
を発生させないガラススペーサが得られる。The present invention is configured as described above and has the following effects. According to the first aspect of the present invention, the average surface roughness of the portion in contact with the substrate is 1 μm.
m or less, it is possible to obtain a glass spacer which is unlikely to be displaced from the substrate and does not generate foreign matter.
【００４６】請求項２に記載の発明によれば、基板に接
する部分の平均表面粗さが０．００１〜０．３μmであ
るので、使用温度が６０℃以上になっても、基板とのず
れが生じ難く、異物を発生させないガラススペーサが確
実に得られる。According to the second aspect of the present invention, since the average surface roughness of the portion in contact with the substrate is 0.001 to 0.3 μm, even if the operating temperature exceeds 60 ° C., the deviation from the substrate can occur. And a glass spacer that does not generate foreign matter is reliably obtained.
【００４７】請求項３に記載の発明によれば、請求項１
または２の発明の効果に加えて、基板に接する部分の最
大表面粗さが３μm以下であるので、ガラススペーサの
表面に研磨剤が残存し難くなる。According to the invention described in claim 3, according to claim 1
In addition to the effect of the second aspect, since the maximum surface roughness of the portion in contact with the substrate is 3 μm or less, the abrasive hardly remains on the surface of the glass spacer.
【００４８】請求項４に記載の発明によれば、請求項１
〜３の発明の効果に加えて、基板との熱膨張係数の差が
２×１０-6℃-1以下であるので、使用温度が６０℃以上
の環境下でも、ガラススペーサと基板のずれの発生を確
実に防止できる。According to the invention described in claim 4, according to claim 1
In addition to the effects of the inventions of (1) to (3), the difference between the thermal expansion coefficient of the substrate and that of the substrate is 2 × 10 −6 ° C.- 1 or less. Generation can be reliably prevented.
【００４９】請求項５に記載の発明によれば、請求項１
〜４の発明の効果に加えて、ガラススペーサの電気伝導
率が１×１０7(Ω・m)-1以上であるので、静電気が基板
上に溜まり難く、記録読み出しエラーが発生し難くな
る。According to the invention of claim 5, according to claim 1,
In addition to the effects of the inventions of (1) to (4), since the electric conductivity of the glass spacer is 1 × 10 7 (Ω · m) −1 or more, static electricity hardly accumulates on the substrate, and recording and reading errors hardly occur.
【００５０】請求項６に記載の発明によれば、上記ガラ
ススペーサを用いるので、記録読み出し速度が早く、か
つ、エラーの少ない情報記録装置が得られる。According to the sixth aspect of the present invention, since the glass spacer is used, an information recording apparatus having a high recording / reading speed and having few errors can be obtained.
【図１】ハードディスクの内部構造の略図である。FIG. 1 is a schematic diagram of the internal structure of a hard disk.
【図２】図１のＡ−Ａ鎖線にしたがう略断面図である。FIG. 2 is a schematic sectional view taken along the line AA in FIG. 1;
１ ハードディスク １０ 情報記録媒体用基板 １１ ガラススペーサ １２ ガラススペーサ固定治具 １３ 磁気ヘッド １４ 磁気ヘッドアーム １５ スピンドル １６ ケース １７ モーター DESCRIPTION OF SYMBOLS 1 Hard disk 10 Information recording medium substrate 11 Glass spacer 12 Glass spacer fixing jig 13 Magnetic head 14 Magnetic head arm 15 Spindle 16 Case 17 Motor
Claims (6)
表面粗さが１μm以下であるガラススペーサ。1. A glass spacer having an average surface roughness of 1 μm or less at a portion in contact with an information recording medium substrate.
表面粗さが０．００１〜０．３μmであるガラススペー
サ。2. A glass spacer having an average surface roughness of 0.001 to 0.3 μm at a portion in contact with an information recording medium substrate.
表面粗さが３μm以下である請求項１または２に記載の
ガラススペーサ。3. The glass spacer according to claim 1, wherein the maximum surface roughness of a portion in contact with the information recording medium substrate is 3 μm or less.
が２×１０-6℃-1以下である請求項１〜３のいずれか１
項に記載のガラススペーサ。4. The method according to claim 1, wherein a difference in thermal expansion coefficient between the substrate and the information recording medium substrate is 2 × 10 −6 ° C.- 1 or less.
The glass spacer according to the item.
ある請求項１〜４のいずれか１項に記載のガラススペー
サ。5. The glass spacer according to claim 1, wherein the glass spacer has an electric conductivity of 1 × 10 7 (Ω · m) −1 or more.
ラススペーサを用いた情報記録装置。6. An information recording apparatus using the glass spacer according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000125922A JP4136268B2 (en) | 2000-04-26 | 2000-04-26 | Glass spacer and information recording apparatus using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000125922A JP4136268B2 (en) | 2000-04-26 | 2000-04-26 | Glass spacer and information recording apparatus using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001307452A true JP2001307452A (en) | 2001-11-02 |
| JP4136268B2 JP4136268B2 (en) | 2008-08-20 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000125922A Expired - Lifetime JP4136268B2 (en) | 2000-04-26 | 2000-04-26 | Glass spacer and information recording apparatus using the same |
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