JPH01304174A - Polishing fluid and method of polishing hard disc base plate - Google Patents
Polishing fluid and method of polishing hard disc base plateInfo
- Publication number
- JPH01304174A JPH01304174A JP63134478A JP13447888A JPH01304174A JP H01304174 A JPH01304174 A JP H01304174A JP 63134478 A JP63134478 A JP 63134478A JP 13447888 A JP13447888 A JP 13447888A JP H01304174 A JPH01304174 A JP H01304174A
- Authority
- JP
- Japan
- Prior art keywords
- polishing
- abrasive grains
- hard disk
- sintered
- polishing liquid
- 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
- 238000005498 polishing Methods 0.000 title claims abstract description 107
- 239000012530 fluid Substances 0.000 title abstract 7
- 238000007517 polishing process Methods 0.000 title description 4
- 239000006061 abrasive grain Substances 0.000 claims abstract description 100
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 15
- 239000002904 solvent Substances 0.000 claims abstract description 13
- 239000000758 substrate Substances 0.000 claims description 81
- 239000007788 liquid Substances 0.000 claims description 54
- 239000002245 particle Substances 0.000 claims description 32
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 21
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 21
- 239000000919 ceramic Substances 0.000 claims description 17
- 239000003082 abrasive agent Substances 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 16
- 230000003746 surface roughness Effects 0.000 abstract description 44
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 13
- 238000012545 processing Methods 0.000 abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 8
- 239000006185 dispersion Substances 0.000 abstract 2
- 239000003125 aqueous solvent Substances 0.000 abstract 1
- 239000004744 fabric Substances 0.000 abstract 1
- 238000004062 sedimentation Methods 0.000 description 7
- 239000004745 nonwoven fabric Substances 0.000 description 6
- 239000000956 alloy Substances 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000011521 glass Substances 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 3
- 229910010271 silicon carbide Inorganic materials 0.000 description 3
- 239000004094 surface-active agent Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000002270 dispersing agent Substances 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 150000002843 nonmetals Chemical class 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
Landscapes
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野]
本発明は、磁気ディスク等のハードディスク用基板表面
を研磨する際に使用する研磨液に関するものであり、さ
らにはその研磨液を用いたハードディスク用基板の研磨
方法に関するものである。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a polishing liquid used when polishing the surface of a substrate for a hard disk such as a magnetic disk, and further relates to a polishing liquid for use in hard disks using the polishing liquid. The present invention relates to a method for polishing a substrate.
〔発明の概要]
本発明は、焼結砥粒を主体とする研磨材が溶媒中に分散
されてなる研磨液において、上記焼結砥粒に破砕砥粒を
所定量添加することにより、大きな表面粗度が得られる
研磨液を提供しようとするものである。[Summary of the Invention] The present invention provides a polishing liquid in which an abrasive mainly composed of sintered abrasive grains is dispersed in a solvent, and by adding a predetermined amount of crushed abrasive grains to the sintered abrasive grains, a large surface The purpose of this invention is to provide a polishing liquid that provides a high level of roughness.
また本発明は、前述の焼結砥粒と破砕砥粒とからなる研
磨材が溶媒中に分散された研磨液を使用してハードディ
スク用のセラミックス基板表面を研磨することにより、
ハードディスク用基板に必要な表面粗度を得ようとする
ものである。Further, the present invention provides a method of polishing the surface of a ceramic substrate for a hard disk using a polishing liquid in which an abrasive material consisting of the above-mentioned sintered abrasive grains and crushed abrasive grains is dispersed in a solvent.
The objective is to obtain the surface roughness required for hard disk substrates.
〔従来の技術]
例えば、コンピュータ等の記憶媒体としては、ランダム
アクセスが可能な円盤状の磁気ディスクが広く用いられ
ており、なかでも応答性に優れること、記憶容量が多い
こと等から、ハードディスク用基板にセラミックス板や
ガラス板あるいは表面がアルマイト処理されたA1合金
等の硬質材料を用いた磁気ディスクが使用されるように
なっている。[Prior Art] For example, disk-shaped magnetic disks that can be randomly accessed are widely used as storage media for computers and the like. Magnetic disks whose substrates are made of hard materials such as ceramic plates, glass plates, or A1 alloys whose surfaces are alumite-treated have come to be used.
上記磁気ディスクは、例えばハードディスク用基板等の
上に記録再生に関与する磁性層と該磁性層を保護する保
護膜層及び走行性の向上を図る潤滑剤層等が順次積層形
成されたもので、円周方向に高速で回転して同心円状の
多数のトラックに情報の記録再生を行うものである。The above-mentioned magnetic disk is one in which, for example, a magnetic layer involved in recording and reproduction, a protective film layer that protects the magnetic layer, a lubricant layer that improves running properties, etc. are sequentially laminated on a hard disk substrate or the like. It rotates at high speed in the circumferential direction to record and reproduce information on a large number of concentric tracks.
ところで、このような磁気ディスクにあっては、磁性層
形成前のハードディスク用基板の表面が微細な凹凸を有
していることが必要とされる。すなわち上記微細な凹凸
は、磁気ディスクの走行性や耐久性又は出力に大きく関
与し、さらには基板上に被膜される磁性層の付着力の向
上にも関与するものであるからである。Incidentally, in such a magnetic disk, it is necessary that the surface of the hard disk substrate before the magnetic layer is formed has fine irregularities. That is, the above-mentioned fine irregularities greatly contribute to the running performance, durability, and output of the magnetic disk, and also contribute to improving the adhesion of the magnetic layer coated on the substrate.
この微細な凹凸を形成する手法としては、例えば研磨加
工の一種であるポリシング加工が挙げられる。上記ボリ
シング加工は、研磨用の研磨材を水又はオイル等で混合
して液化させたスラリー状砥粒、すなわち研磨液を平坦
な面を有する定盤と被加工物の間に供給し、加工圧力を
加えながら定盤の回転運動を利用して研磨材の切刃で被
加工物から必要量の取り代を取り除き、定盤の持つ平面
度を転写する加工方法である。An example of a method for forming these fine irregularities is polishing, which is a type of polishing. In the above-mentioned borishing process, slurry-like abrasive grains made by mixing an abrasive material with water or oil, etc., and liquefying it, that is, a polishing liquid, is supplied between a surface plate with a flat surface and a workpiece, and the machining pressure is This is a processing method that transfers the flatness of the surface plate by removing the necessary amount of machining allowance from the workpiece with an abrasive cutting edge using the rotational movement of the surface plate while adding
ところで、上記ハードディスク用y&阪表面のボリシン
グ加工において使用される研+91は、例えば直径0.
2〜0.3ミクロン程度の細かい酸化アルミナの粒を焼
結した焼結砥粒を研磨材に用い、これに水又はオイル、
分散剤、界面活性剤等を混合してスラリー状としたもの
を使用している。By the way, the grinder +91 used in the boring process of the hard disk surface has a diameter of, for example, 0.
Sintered abrasive grains made by sintering fine alumina oxide grains of about 2 to 0.3 microns are used as an abrasive, and water or oil,
A slurry made by mixing a dispersant, a surfactant, etc. is used.
ところが、上記ハードディスク用基板においては、耐久
性や出力の観点からある一定の値(例えば、中心線平均
粗さRa=35人程度)の表面粗度が要求されるが、市
販される焼結砥粒(ポリシング液)ではその値を満足さ
せるには非常に難しい。すなわち、上記焼結砥粒は細か
い酸化アルミナの粒の固まりであるためにその強度は余
り強くなく、ポリシング加工時にその砥粒が砕け、実際
に加工に関与する粒径は小となってしまう。このため上
記焼結砥粒のみでは、ハードディスク用基板に必要な表
面粗度を得ることができない。However, the above-mentioned hard disk substrate requires a surface roughness of a certain value (for example, center line average roughness Ra = about 35 people) from the viewpoint of durability and output, but commercially available sintered abrasives It is extremely difficult to satisfy this value with grains (polishing liquid). That is, since the sintered abrasive grains are agglomerates of fine alumina oxide grains, their strength is not very strong, and the abrasive grains break during polishing, resulting in a small particle size actually involved in the processing. Therefore, the surface roughness required for a hard disk substrate cannot be obtained using only the sintered abrasive grains.
そこで、上記焼結砥粒の粒径を大きくしてその表面粗度
を大とすることも考えられるが、表面粗度は、第3図に
示すようにある程度砥粒径に比例して大きくなるが、前
述のように実際に加工に関与する粒径は小さくなるため
にその表面粗度には限界がある。特に、表面が硬い酸化
物からなるセラミックス基板やガラス板あるいはアルマ
イト処理が施されたA2合金基板等にあっては顕著であ
る。このため従来は、上記ハードディスク用基板に必要
な表面粗度を得るために、さらにその基板表面に対して
テクスチャリング加工等が施されている。したがって、
ハードディスク用基板表面の研磨加工は二工程かかるた
めにコストアップとなっている。Therefore, it is possible to increase the surface roughness by increasing the particle size of the sintered abrasive grains, but as shown in Figure 3, the surface roughness increases to some extent in proportion to the abrasive grain size. However, as mentioned above, since the grain size actually involved in processing becomes small, there is a limit to the surface roughness. This is particularly noticeable in ceramic substrates or glass plates whose surfaces are made of hard oxides, or A2 alloy substrates subjected to alumite treatment. For this reason, conventionally, in order to obtain the necessary surface roughness for the hard disk substrate, texturing processing or the like is further performed on the surface of the substrate. therefore,
Polishing the surface of a hard disk substrate requires two steps, which increases costs.
他方、焼結砥粒の粒径が大きくなるとポリシング加工中
に砥粒が沈降し易くなる。このため、ハードディスク用
基板表面を両面研磨する場合には、その基板両面に供給
される焼結砥粒の粒径にばらつきを生じ、これによりそ
の表面粗度にばらつきを生ずることになる0例えばその
ハードディスク用基板の下面側の中心線平均粗さは、上
面側の中心線平均粗さの約1.5〜2倍の表面粗度にも
なる。このため、得られる磁気ディスクはスペーシング
ロス等を生じその性能に差が生じ、信頼性の高い磁気デ
ィスクを提供することができない。On the other hand, as the particle size of the sintered abrasive grains increases, the abrasive grains tend to settle during polishing. For this reason, when polishing both sides of the surface of a hard disk substrate, the particle size of the sintered abrasive grains supplied to both sides of the substrate varies, which causes variations in the surface roughness. The centerline average roughness of the lower surface of the hard disk substrate is about 1.5 to 2 times the centerline average roughness of the upper surface. As a result, the resulting magnetic disks suffer from spacing loss and other differences in performance, making it impossible to provide highly reliable magnetic disks.
そこで本発明は、上述のような従来の問題に鑑みて提案
されたものであって、大きな表面粗度が得られる研磨液
を提供することを目的とするものである。また、本発明
は砥粒の沈降を防止する研mン夜を提イ共することを目
的とするものである。Therefore, the present invention has been proposed in view of the above-mentioned conventional problems, and an object of the present invention is to provide a polishing liquid that can provide a high surface roughness. Another object of the present invention is to provide a polishing method that prevents sedimentation of abrasive grains.
さらに本発明は、ハードディスク用基板に必要な表面粗
度が得られるハードディスク用基板の研磨方法を提供す
ることを目的とするものである。A further object of the present invention is to provide a method for polishing a hard disk substrate that provides the surface roughness required for the hard disk substrate.
また、本発明は基板両面の表面粗度を均一にするハード
ディスク用基板の研磨方法を提供することを目的とする
ものである。Another object of the present invention is to provide a method for polishing a hard disk substrate to make the surface roughness of both surfaces of the substrate uniform.
本発明者等は、前述の目的を達成せんものと長期間に亘
り研究を重ねた結果、大きな表面粗度を得るのに焼結砥
粒の粒径より大径の破砕砥粒が有効であり、沈降防止に
ポリビニルアルコールが有効であるとの知見を得て本発
明を完成するに至った。The inventors of the present invention have conducted research over a long period of time to achieve the above-mentioned objective, and have found that crushing abrasive grains with a diameter larger than that of sintered abrasive grains are effective in obtaining a large surface roughness. The present invention was completed based on the knowledge that polyvinyl alcohol is effective in preventing sedimentation.
すなわち、本発明の研磨液は、焼結砥粒を主体とする研
磨材が溶媒中に分散されてなる研磨液において、前記焼
結砥粒100重景重量対して1〜30重量部の破砕砥粒
が添加されていることを特徴とするものである。That is, the polishing liquid of the present invention is a polishing liquid in which an abrasive mainly composed of sintered abrasive grains is dispersed in a solvent, and in which 1 to 30 parts by weight of crushed abrasive is added to 100 parts by weight of the sintered abrasive grains. It is characterized by the addition of grains.
さらに本発明の研磨液は、上記破砕砥粒の粒径が焼結砥
粒の粒径よりも大であることを特徴とするものである。Furthermore, the polishing liquid of the present invention is characterized in that the particle size of the crushed abrasive grains is larger than the particle size of the sintered abrasive grains.
さらに本発明の研磨液は、前記研磨液に沈降防止剤であ
るポリビニルアルコールが添加されたことを特徴とする
ものである。Furthermore, the polishing liquid of the present invention is characterized in that polyvinyl alcohol, which is an anti-settling agent, is added to the polishing liquid.
また本発明のハードディスク用基板の研磨方法は、ハー
ドディスク用のセラミックス基板表面を研磨するに際し
、焼結砥粒100重量部と破砕砥粒1〜30重量部とか
らなる研磨材が溶媒中に分散された研Ig液を使用する
ことを特徴とするものである。Further, in the method for polishing a hard disk substrate of the present invention, when polishing the surface of a ceramic substrate for a hard disk, an abrasive material consisting of 100 parts by weight of sintered abrasive grains and 1 to 30 parts by weight of crushed abrasive grains is dispersed in a solvent. This method is characterized by using a highly refined Ig solution.
また本発明のハードディスク用基板の研磨方法は、ハー
ドディスク用のセラミックス基板表面を両面研磨するに
際し、焼結砥粒100重量部と破砕砥粒1〜30重量部
とからなる研磨材及び沈降防止剤であるポリビニルアル
コールが溶媒中に分散された研磨液を使用することを特
徴とするものである。Further, in the method for polishing a hard disk substrate of the present invention, when polishing both sides of the surface of a ceramic substrate for a hard disk, an abrasive consisting of 100 parts by weight of sintered abrasive grains and 1 to 30 parts by weight of crushed abrasive grains and an anti-settling agent are used. This method is characterized by the use of a polishing liquid in which a certain polyvinyl alcohol is dispersed in a solvent.
上記破砕砥粒は、例えばアルミナ質研削材又は炭化珪素
質研削材を粉砕機等により粉砕した後整粒したもので、
細かい粒の固まりである焼結砥粒とは異なり、いわゆる
粒子単体のものである。このため、上記破砕砥粒は強度
的に強く、研磨加工を施してもその粒子が砕ける虞れが
ない。The above-mentioned crushing abrasive grains are obtained by pulverizing an alumina abrasive material or a silicon carbide abrasive material using a pulverizer, etc., and then grading the particles.
Unlike sintered abrasive grains, which are agglomerates of fine grains, abrasive grains are so-called single grains. Therefore, the above-mentioned crushing abrasive grains are strong and there is no risk of the particles breaking even when subjected to polishing.
またその破砕砥粒の割合は、前記焼結砥粒100重量部
に対して1〜30重量部とすることが好ましい。すなわ
ち、上記破砕砥粒が1重量部以下であると、大きな表面
粗度を必要とするハードディスク用基板の研磨に対して
はその破砕砥粒の添加量が不足し、所望の表面粗度を得
ることができない。他方、その破砕砥粒を30重量部以
上添加しても、基板の表面粗度はその添加量に比して大
きくならないためこれ以上添加しても無意味である。The proportion of the crushed abrasive grains is preferably 1 to 30 parts by weight based on 100 parts by weight of the sintered abrasive grains. That is, if the amount of the above-mentioned crushing abrasive grains is 1 part by weight or less, the amount of the crushing abrasive grains added is insufficient for polishing a hard disk substrate that requires a large surface roughness, and the desired surface roughness cannot be obtained. I can't. On the other hand, even if 30 parts by weight or more of the crushing abrasive grains are added, the surface roughness of the substrate will not increase compared to the amount added, so it is meaningless to add more than this amount.
また上記破砕砥粒の粒径は、前記焼結砥粒の粒径よりも
大であることが好ましく、さらにはその粒度(番手)を
小さくすることが好ましい。すなわち、上記破砕砥粒の
粒径が焼結砥粒の粒径と同じ或いは小さいと、やはり大
きな表面粗度が得られない。なお研磨加工を施す際は、
被加工物に必要な表面粗度に応じて、その粒径及び粒度
を適宜選択すればよい。Further, the particle size of the crushing abrasive grains is preferably larger than the particle size of the sintered abrasive grains, and further preferably, the particle size (count) is smaller. That is, if the particle size of the crushed abrasive grains is the same as or smaller than the particle size of the sintered abrasive grains, a large surface roughness cannot be obtained. When performing polishing,
The grain size and grain size may be appropriately selected depending on the surface roughness required for the workpiece.
かかる破砕砥粒としては、アルミナ質系の破砕砥粒1例
えば高裁工業社製のハイランプ、ホワイト・ハイランプ
、タカミジン等が挙げられ、また炭化珪素質系の破砕砥
粒、同じく高裁工業社製のブラック・ハイラップ、グリ
ーン・ハイラップ等が挙げられる。上記ハイラップは、
熔融アルミナ質研削材でチタン、シリカ等を少量含有し
た暗褐色結晶で最も靭性が高く最も広く利用されている
研磨材である。ホワイト・ハイラップは、純度の極めて
高い熔融アルミナ質研削材で白色結晶であり、A研磨材
(JIS R6210−1958)に比して硬度が高
いが若干脆さを持った研磨材である、また、タカミジン
は、酸化アルミナを1300°C以上の高温で焼成後粉
砕微粒子となし整粒した乳白色の粒形の良い研磨材であ
り、硬度は熔融アルミナ質研削材より軟らかく粒子径が
平均2゜5ミクロンで最も小さい粒子である。上記ブラ
ンク・ハイラップは、黒色の結晶をした研削材で熔融ア
ルミナ質研削材より硬度が高いが脆さがあり、例えば石
材、硝子、陶磁器等の非金属の研磨に好適な研磨材であ
る。またグリーン・ハイラップは、純度が極めて高い炭
化珪素質研削材で緑色結晶であり、C研磨材(JIS
R6210−1958)に比して硬度が貰<脆<且つ
熱伝導度のよい研磨材である。Examples of such crushing abrasive grains include alumina-based crushing abrasive grains such as Hi-Lamp, White Hi-Lamp, and Takamijin manufactured by Kosho Kogyo Co., Ltd., and silicon carbide-based crushing abrasive grains such as Black, also manufactured by Kosho Kogyo Co., Ltd. - Examples include high lap, green high lap, etc. The above high lap is
It is a fused alumina abrasive with dark brown crystals containing a small amount of titanium, silica, etc. It has the highest toughness and is the most widely used abrasive. White Hi-Lap is an extremely pure fused alumina abrasive with white crystals, which is harder than A abrasive (JIS R6210-1958) but slightly brittle. Takamijin is a milky-white abrasive with good grain shape made by firing alumina oxide at a high temperature of 1300°C or higher and then pulverizing it into fine particles.It is softer than fused alumina abrasives and has an average particle size of 2.5 microns. It is the smallest particle in The Blank Hi-Lap is a black crystalline abrasive that is harder but more brittle than a fused alumina abrasive, and is suitable for polishing nonmetals such as stone, glass, and ceramics. In addition, Green Hi-Lap is an extremely pure silicon carbide abrasive with green crystals, and is a C abrasive (JIS
R6210-1958) is an abrasive with less hardness than brittleness and good thermal conductivity.
上記ポリビニルアルコール(PVA)は、研磨液に完全
に溶解し分散するもので、研磨液としての性能を害せず
又研磨装置等にも悪影響を及ぼすことなく研磨材の沈降
を防止するものである。このため、特に大きな表面粗度
を必要とするハードディスク用基板の表面を研磨するに
は好適である。The above-mentioned polyvinyl alcohol (PVA) completely dissolves and disperses in the polishing liquid, and prevents the abrasive from settling without impairing the performance of the polishing liquid or adversely affecting the polishing equipment. . Therefore, it is particularly suitable for polishing the surface of a hard disk substrate that requires a high surface roughness.
すなわち、大きな表面粗度を得るためには、破砕砥粒の
粒径を焼結砥粒の粒径よりも大としているため、特にそ
の破砕砥粒は下定盤側に沈降し易くなっている。したが
って、その研磨液に沈降防止材であるポリビニルアルコ
ールを添加すれば、砥粒の沈降が防止されこれにより基
板両面の表面粗度に差が生ずることがなくなる。また、
上記ポリビニルアルコールは安価であるので、コスト的
にも満足でき安価な研磨液を掃供できる。That is, in order to obtain a large surface roughness, the particle size of the crushed abrasive grains is made larger than the particle size of the sintered abrasive grains, so the crushed abrasive grains in particular tend to settle toward the lower surface plate. Therefore, if polyvinyl alcohol, which is an antisedimentation agent, is added to the polishing liquid, the abrasive grains are prevented from settling, thereby eliminating the difference in surface roughness between the two surfaces of the substrate. Also,
Since the above-mentioned polyvinyl alcohol is inexpensive, it is possible to supply an inexpensive polishing liquid that is satisfactory in terms of cost.
なお、沈降防止剤として前述のポリビニルアルコールの
他に、例えば水溶性の高分子剤等も使用可能である。In addition to the above-mentioned polyvinyl alcohol, for example, a water-soluble polymeric agent can also be used as the anti-settling agent.
他方、溶媒としては水又はオイル、分lit剤、界面活
性剤等が挙げられる。なお、分散剤及び界面活性剤は必
要に応じて適宜使用すればよい。On the other hand, examples of the solvent include water or oil, a separating agent, a surfactant, and the like. In addition, a dispersant and a surfactant may be used appropriately as necessary.
また、前記焼結砥粒を主体とする研磨材を溶媒中に分散
した研磨液は、市販されているものを使用する。これは
、研磨液として必要特性を生かすためと、添加する破砕
砥粒の懸濁性を良くするためである。Furthermore, a commercially available polishing liquid in which an abrasive material mainly composed of the sintered abrasive grains is dispersed in a solvent is used. This is to make use of the characteristics required as a polishing liquid and to improve the suspension of the crushed abrasive grains added.
前記ハードディスク用基板としては、セラミックス基板
が使用される。なお、セラミックス基板には、表面研磨
が施される面が酸化物であるセラミックス単体からなる
セラミックス板、ガラス板。A ceramic substrate is used as the hard disk substrate. Note that the ceramic substrate includes a ceramic plate and a glass plate made of a single ceramic whose surface to be polished is an oxide.
アルマイト処理が施されたA42合金板等が使用される
。An alumite-treated A42 alloy plate or the like is used.
[作用]
本発明の研磨液によれば、焼結砥粒を主体とする研磨材
に所定量の破砕砥粒を添加しているので、研磨加工時に
砥粒が砕けることがない。これにより、砥粒径が確保さ
れるため大きな表面粗度が得られる。また、上記破砕砥
粒の粒径を焼結砥粒の粒径より大とすることで、やはり
大きな表面粗度が得られる。さらに、これら研磨材にポ
リビニルアルコールを添加することで、砥粒の沈降が防
止される。[Function] According to the polishing liquid of the present invention, since a predetermined amount of crushing abrasive grains are added to the abrasive material mainly composed of sintered abrasive grains, the abrasive grains are not crushed during polishing. This ensures the abrasive grain size and provides a large surface roughness. Further, by making the particle size of the crushed abrasive grains larger than the particle size of the sintered abrasive grains, a large surface roughness can also be obtained. Furthermore, by adding polyvinyl alcohol to these abrasives, sedimentation of the abrasive grains is prevented.
かかる研磨液を使用してハードディスク用のセラミック
ス基板表面を研磨すると、ハードディスク用基板に必要
な大きな表面粗度が得られるとともにその基板両面の表
面粗度は均一となる。When the surface of a ceramic substrate for a hard disk is polished using such a polishing liquid, a large surface roughness required for the hard disk substrate can be obtained, and the surface roughness on both sides of the substrate can be made uniform.
以下、本発明を具体的な実施例に基づいて説明する。 The present invention will be described below based on specific examples.
先ず、本発明にかかる研磨液を使用してハードディスク
用基板を研磨する研磨装置について説明する。First, a polishing apparatus for polishing a hard disk substrate using a polishing liquid according to the present invention will be described.
上記研磨装置は、第1図に示すように、ハードディスク
用基板(1)を上下方向から挟み込むように配設される
下定盤(2)及び上定盤(3)を主たる構成とするもの
である。これら下定盤(2)及び上定盤(3)は、ハー
ドディスク用基板(1)と接する面が平坦な面を有した
円盤状のもので、互いに反対方向に回転するようになっ
ている。その定盤のうち上定盤(3)は、上下動可能と
なっており前記ハードディスク用基板(1)に所定の加
工圧力を与えるようになっている。また、その下定盤(
2)と上定盤(3)との間には、上記ハードディスク用
基板(1)を保持するためのキャリア(4)が配設され
、ここに上記ハードディスク用基板(1)が保持される
。上記キャリア(4)は、装置本体に設けられた太陽ギ
アとインターナルギア(いずれも図示は省略する。)に
よって前記下定盤(2)と同一方向に公転しながら自転
するようになっている。また、前記下定盤(2)と上定
盤(3)には、それぞれポリシングバッド、すなわち不
織布(5) 、 (6)が貼り付けられており、この不
織布(5)、(6)が研磨液を保持し前記ハードディス
ク用基板(1)に接触する。As shown in Fig. 1, the polishing device described above mainly consists of a lower surface plate (2) and an upper surface plate (3) that are arranged to sandwich the hard disk substrate (1) from above and below. . The lower surface plate (2) and the upper surface plate (3) are disk-shaped and have a flat surface that contacts the hard disk substrate (1), and are configured to rotate in opposite directions. Among the surface plates, the upper surface plate (3) is movable up and down and is adapted to apply a predetermined processing pressure to the hard disk substrate (1). Also, the lower surface plate (
A carrier (4) for holding the hard disk substrate (1) is disposed between the hard disk substrate (1) and the hard disk substrate (1). The carrier (4) is configured to rotate while revolving in the same direction as the lower surface plate (2) by a sun gear and an internal gear (both not shown) provided in the main body of the device. Furthermore, polishing pads, that is, nonwoven fabrics (5) and (6), are attached to the lower surface plate (2) and the upper surface plate (3), respectively, and these nonwoven fabrics (5) and (6) are attached to the polishing liquid. and comes into contact with the hard disk substrate (1).
なお、上記上定盤(3)及び該上定盤(3)に貼り付け
られた不織布(6)には、研UWXをハードディスク用
基板(1)に供給するための研磨液供給孔(3a) 。The upper surface plate (3) and the nonwoven fabric (6) attached to the upper surface plate (3) have polishing liquid supply holes (3a) for supplying the polishing UWX to the hard disk substrate (1). .
(6a)が穿設され、この供給孔(3a) 、 (6a
)を通してボリシンダ液が供給されるようになっている
。(6a) are drilled, and these supply holes (3a), (6a
) is supplied with Boricinda liquid.
上記研磨装置を用いてハードディスク用基板を研磨する
には、先ず、ハードディスク用基板(1)をキャリア(
4)に複数枚保持させ、前記上定盤(3)を下降させて
該上定盤(3)と下定盤(2)とでハードディスク用基
板(1)を挟み込む、そして、上記上定盤(3)により
前記ハードディスク用基板(1)に所定の加工圧力を加
える。次に、下定盤(2)及び上定盤(3)並びにキャ
リア(4)をそれぞれ各自回転させると同時に、前記研
磨液供給孔(3a) 、 (6a)を通して研磨液を供
給しながら研磨加工を施す。To polish a hard disk substrate using the polishing device described above, first, the hard disk substrate (1) is placed on the carrier (
4) holds a plurality of hard disk substrates, lowers the upper surface plate (3), and sandwiches the hard disk substrate (1) between the upper surface plate (3) and the lower surface plate (2); 3), a predetermined processing pressure is applied to the hard disk substrate (1). Next, while rotating the lower surface plate (2), upper surface plate (3), and carrier (4), the polishing process is performed while supplying the polishing liquid through the polishing liquid supply holes (3a) and (6a). give
これによれば、前記上下定盤(3) 、 (2)及びキ
ャリア(4)の三者間の相対的回転運動により、ハード
ディスク用基板(1)両面が同時に研磨材の持つ切刃に
より削り取られる。According to this, both surfaces of the hard disk substrate (1) are simultaneously scraped off by the cutting edge of the abrasive material due to the relative rotational movement between the upper and lower surface plates (3), (2) and the carrier (4). .
次に、本発明にかかる研0?&を以下の条件で作製し、
前述の研磨装置を使用してハードディスク用のセラミッ
クス基板表面を研磨したヶすなわち、粒径6μの焼結砥
粒を主体とする研磨材に、粒径6μ1粒度2500番の
アルミナ質破砕砥粒及び粒径10μ2粒度1500番の
アルミナ質破砕砥粒をそれぞれ前記焼結砥粒に対して1
.3,5,10.15重量%となるように添加し、水を
溶媒として1:2(研磨材と水)の割合で混合して研磨
液をそれぞれ作製した。なお、本実施例での研磨液は市
販されているものを使用した。Next, the grinding zero according to the present invention? & was prepared under the following conditions,
The surface of a ceramic substrate for a hard disk was polished using the above-mentioned polishing device. In other words, alumina crushing abrasive grains with a grain size of 6μ1 and grain size 2500 were added to an abrasive material mainly consisting of sintered abrasive grains with a grain size of 6μ1. Alumina crushing abrasive grains with a diameter of 10 μ2 and a grain size of No. 1500 were added for each of the sintered abrasive grains.
.. Polishing liquids were prepared by adding 3%, 5%, and 10.15% by weight of each abrasive and mixing them at a ratio of 1:2 (abrasive and water) using water as a solvent. In this example, a commercially available polishing liquid was used.
一方、セラミックス基板にはアルマイト処理が施された
A1合金基板を使用し、9インチのキャリア5枚にそれ
ぞれ保持させ合計10枚のアルマイト処理基板を研磨し
た。その研磨加工条件は、スェードタイプの不織布を使
用し、上定盤の回転数を60rpmとし、加工圧力を5
0g/cJとして上記組成の研磨液を100mf/分で
供給して7分間の研磨加工を施した。On the other hand, an alumite-treated A1 alloy substrate was used as the ceramic substrate, and a total of 10 alumite-treated substrates were polished by holding them on five 9-inch carriers. The polishing conditions were as follows: Suede type non-woven fabric was used, the rotation speed of the upper surface plate was 60 rpm, and the processing pressure was 5.
A polishing liquid having the above composition was supplied at 100 mf/min at 0 g/cJ, and polishing was performed for 7 minutes.
その結果を第2図に示す。なお、第2図中横軸は破砕砥
粒の添加量(重量%)を示し、縦軸は基板表面の中心線
表面粗さ(人)を示す。また、図中実線は粒径10μの
破砕砥粒を、破線は粒径6μの破砕砥粒をそれぞれ添加
した研磨液による基板表面の中心線平均粗さを示す。The results are shown in FIG. In FIG. 2, the horizontal axis indicates the amount of crushing abrasive grains added (% by weight), and the vertical axis indicates the centerline surface roughness (in terms of surface roughness) of the substrate surface. Further, in the figure, the solid line indicates the center line average roughness of the substrate surface using a polishing liquid to which crushing abrasive grains with a particle size of 10 μm are added, and the broken line represents crushing abrasive grains with a particle size of 6 μm.
第2図から分かるように、破砕砥粒の粒径が焼結砥粒の
粒径と同じである場合(すなわち、第2図中破線で示す
。)は、破砕砥粒の添加■の割合に関係なくその表面粗
度は一定となり、ハードディスク用基板に必要な表面粗
度(35人程度)は得られなかった。他方、破砕砥粒の
粒径が焼結砥粒の粒径よりも大きい場合(すなわち、第
2図中実線で示す。)は、破砕砥粒を1重量%添加した
のみであっても大きな表面粗度が得られ、3〜5重量%
の破砕砥粒の添加で上記ハードディスク用基板に必要な
表面粗度が得られた。また、第2図から分かるように、
その破砕砥粒の添加量をさらに増加してもその添加量に
比して表面粗度の向上が図れないため、その破砕砥粒の
添加量は前記したように焼結砥粒100重量部に対して
1〜30重量部とすることが好ましい。As can be seen from Figure 2, when the particle size of the crushed abrasive grains is the same as the particle size of the sintered abrasive grains (i.e., indicated by the broken line in Figure 2), the ratio of addition of the crushed abrasive grains Regardless, the surface roughness was constant, and the surface roughness required for a hard disk substrate (about 35 people) could not be obtained. On the other hand, if the particle size of the crushed abrasive grains is larger than that of the sintered abrasive grains (in other words, as shown by the solid line in Figure 2), even if only 1% by weight of the crushed abrasive grains are added, a large surface Roughness is obtained, 3-5% by weight
By adding the crushing abrasive grains, the surface roughness required for the hard disk substrate was obtained. Also, as can be seen from Figure 2,
Even if the amount of the crushing abrasive grains added is further increased, the surface roughness cannot be improved compared to the amount added, so the amount of the crushing abrasive grains added is 100 parts by weight of the sintered abrasive grains as described above. It is preferable to use 1 to 30 parts by weight.
したがって、本発明の研[?[によれば、市販されてい
る研磨液に安価な破砕砥粒を所定量添加することのみで
、容易にハードディスク用基板に必要な表面粗度が得ら
れる。したがって、研に加工は一工程でその目的が達成
されるので、従来からのテクスチャリング工程が省略で
き製造工程の筒略化が図れる。Therefore, the research of the present invention [? According to [, the surface roughness required for a hard disk substrate can be easily obtained by simply adding a predetermined amount of inexpensive crushing abrasive grains to a commercially available polishing liquid. Therefore, since the purpose of the grinding process is achieved in one step, the conventional texturing process can be omitted and the manufacturing process can be simplified.
また本実施例では、沈陣防止剤であるポリビニルアルコ
ールを添加した研磨液を以下の条件で作製し、その研磨
液を使用してやはり前述の研磨装置を用いてハードディ
スク用のセラミックス基板表面を研磨した。In addition, in this example, a polishing liquid to which polyvinyl alcohol, which is an anti-sinking agent, was added was prepared under the following conditions, and the polishing liquid was used to polish the surface of a ceramic substrate for a hard disk using the above-mentioned polishing apparatus. did.
すなわち、粒径6μの焼結砥粒を主体とする研磨材に、
粒径10μ1粒度1500番のアルミナ質破砕砥粒を前
記焼結砥粒に対して5重量%となるように添加し、さら
にポリビニルアルコールを全体の研磨液に対して0.3
,0.5,1.0゜3.0重量%となるようにそれぞれ
添加し、水を溶媒として1:2(研磨材と水)の割合で
混合して研磨液をそれぞれ作製した。In other words, an abrasive material mainly composed of sintered abrasive grains with a particle size of 6μ,
Alumina crushing abrasive grains with a particle size of 10μ1 and a particle size of No. 1500 were added to the sintered abrasive grains in an amount of 5% by weight, and polyvinyl alcohol was added in an amount of 0.3% by weight based on the entire polishing liquid.
, 0.5, 1.0°, and 3.0% by weight, respectively, and mixed at a ratio of 1:2 (abrasive material and water) using water as a solvent to prepare polishing liquids.
一方、セラミックス基板には先のものと同様アルマイト
処理が施されたへ!合金基板を使用し、9インチのキャ
リア5枚にそれぞれ保持させ合計5枚の5.25インチ
のアルマイト処理基板を研磨した。その研磨加工条件は
、やはりスェードタイプの不織布を使用し、上定盤の回
転数を5Orpmとし、加工圧力を50g/cJとして
上記組成の研磨液を100d/分で供給して5分間の研
磨加工を施した。On the other hand, the ceramic substrate was anodized like the previous one! Using alloy substrates, a total of five 5.25-inch alumite-treated substrates were polished by holding them on five 9-inch carriers. The polishing conditions were as follows: suede type non-woven fabric was used, the rotation speed of the upper surface plate was 5 Orpm, the processing pressure was 50 g/cJ, and the polishing liquid with the above composition was supplied at 100 d/min for 5 minutes. was applied.
その結果を第1表に示す。なお、第1表中Raは上定盤
側の基板表面の中心線平均粗さ、Rbは下定盤側の基板
表面の中心線平均粗さを示す。The results are shown in Table 1. In Table 1, Ra indicates the center line average roughness of the substrate surface on the upper surface plate side, and Rb indicates the center line average roughness of the substrate surface on the lower surface plate side.
第1表
上記第1表から分かるように、ポリビニルアルコールが
0.3重量%又は0.5重量%添加された研磨液を使用
して研磨加工を施した場合は、その基板両面の表面粗度
にばらつきが見られた。すなわち、0.3重量%、0.
5重量%のポリビニルアルコールの添加量では、砥粒の
沈降を完全に防止しきれないためであると考えられる。Table 1 As can be seen from Table 1 above, when polishing is performed using a polishing liquid containing 0.3% or 0.5% by weight of polyvinyl alcohol, the surface roughness of both surfaces of the substrate Variations were observed. That is, 0.3% by weight, 0.
This is believed to be because the addition amount of polyvinyl alcohol of 5% by weight does not completely prevent sedimentation of the abrasive grains.
他方、そのポリビニルアルコールの添加量が1.0重量
%の研磨液を使用して研磨加工を施した場合は、基板両
面の表面粗度にばらつきがなく両面ともに略同じ表面粗
度が得られた。また、ポリビニルアルコールの添加量が
3.0重量%の場合にも、やはりその基板両面の表面粗
度は同し値が得られた。On the other hand, when polishing was performed using a polishing liquid containing 1.0% by weight of polyvinyl alcohol, there was no variation in surface roughness on both sides of the substrate, and almost the same surface roughness was obtained on both sides. . Furthermore, even when the amount of polyvinyl alcohol added was 3.0% by weight, the same surface roughness values were obtained on both sides of the substrate.
したがって、上記ポリビニルアルコールは砥粒の沈降防
止に有効であると言える。よって、このポリビニルアル
コールを研磨液に添加することで、基板両面の表面粗度
を均一化することができ、信頼性の高いハードディスク
用基板が提供できる。Therefore, it can be said that the above-mentioned polyvinyl alcohol is effective in preventing sedimentation of abrasive grains. Therefore, by adding this polyvinyl alcohol to the polishing liquid, the surface roughness on both sides of the substrate can be made uniform, and a highly reliable hard disk substrate can be provided.
以上の説明からも明らかなように、本発明の研磨液によ
れば、焼結砥粒を主体とする研磨材に所定量の破砕砥粒
を添加しているので、研磨加工時に該破砕砥粒は砕ける
ことなくその粒径が確保され、これにより大きな表面粗
度が得られる。また、上記破砕低粒の粒径を焼結砥粒の
粒径より大としているので、やはり大きな表面粗度が達
成される。As is clear from the above explanation, according to the polishing liquid of the present invention, a predetermined amount of crushed abrasive grains is added to the abrasive material mainly composed of sintered abrasive grains, so that the crushed abrasive grains are added during polishing. The particle size is maintained without shattering, resulting in a large surface roughness. Further, since the particle size of the crushed small grains is made larger than the particle size of the sintered abrasive grains, a large surface roughness is also achieved.
さらに、本発明の研T2液によれば、ポリビニルアルコ
ールを研磨液に添加しているので、砥粒の沈降を防止す
ることができる。Furthermore, according to the polishing T2 liquid of the present invention, since polyvinyl alcohol is added to the polishing liquid, sedimentation of the abrasive grains can be prevented.
一方、本発明のハードディスク用基板の研磨方法によれ
ば、破砕砥粒が添加された研磨液を使用して研磨加工を
施しているので、そのハードディスク用基板に必要な表
面粗度を容易に得ることができる
また、さらに本発明のハードディスク用基板の研磨方法
によれば、破砕砥粒が添加された研磨液に沈降防止剤で
あるポリビニルアルコールを添加しているので、砥粒の
沈降が防止されその基板両面の表面粗度は均一となる。On the other hand, according to the method of polishing a hard disk substrate of the present invention, polishing is performed using a polishing liquid to which crushing abrasive grains are added, so that the surface roughness required for the hard disk substrate can be easily obtained. Furthermore, according to the method for polishing a hard disk substrate of the present invention, since polyvinyl alcohol, which is an anti-settling agent, is added to the polishing liquid to which crushing abrasive grains have been added, sedimentation of the abrasive grains is prevented. The surface roughness on both sides of the substrate becomes uniform.
これにより、磁気ディスクとしての出力にもばらつきが
生ずることがなく、信鯨性の高いハードディスク用基板
を提供することができる。Thereby, there is no variation in output as a magnetic disk, and it is possible to provide a highly reliable hard disk substrate.
第1図は本発明に使用した研磨装置の一例を示す概略断
面図であり、第2図は本発明を適用した研磨液を使用し
て研磨加工を施した際の破砕砥粒の添加量と表面粗度の
関係を示す特性図であり、第3図は砥粒径と表面粗度の
関係を示す特性図である。
1・・・ハードディスク用基板
2・・・下定盤
3・・・上定盤
4・・・キャリア
5.6・・・不織布
特許出願人 ソニー株式会社
代理人 弁理士 小 池 晃(他二名)−○
つ
ヤノ
m¥6a@c評!h−’;:@ヤノFigure 1 is a schematic cross-sectional view showing an example of the polishing apparatus used in the present invention, and Figure 2 shows the amount of crushed abrasive grains added when polishing is performed using the polishing liquid to which the present invention is applied. FIG. 3 is a characteristic diagram showing the relationship between surface roughness, and FIG. 3 is a characteristic diagram showing the relationship between abrasive grain size and surface roughness. 1... Hard disk substrate 2... Lower surface plate 3... Upper surface plate 4... Carrier 5. 6... Nonwoven fabric patent applicant Sony Corporation representative Patent attorney Akira Koike (and two others) - ○ Tsuyano m¥6a@c review! h-';: @ Yano
Claims (5)
てなる研磨液において、 前記焼結砥粒100重量部に対して1〜30重量部の破
砕砥粒が添加されていることを特徴とする研磨液。(1) In a polishing liquid in which an abrasive mainly composed of sintered abrasive grains is dispersed in a solvent, 1 to 30 parts by weight of crushing abrasive grains are added to 100 parts by weight of the sintered abrasive grains. A polishing liquid characterized by:
ことを特徴とする請求項(1)記載の研磨液。(2) The polishing liquid according to claim (1), wherein the particle size of the crushed abrasive grains is larger than the particle size of the sintered abrasive grains.
れたことを特徴とする請求項(1)又は(2)記載の研
磨液。(3) The polishing liquid according to claim (1) or (2), further comprising polyvinyl alcohol as an anti-settling agent.
するに際し、焼結砥粒100重量部と破砕砥粒1〜30
重量部とからなる研磨材が溶媒中に分散された研磨液を
使用することを特徴とするハードディスク用基板の研磨
方法。(4) When polishing the surface of a ceramic substrate for a hard disk, use 100 parts by weight of sintered abrasive grains and 1 to 30 parts by weight of crushed abrasive grains.
1. A method for polishing a hard disk substrate, comprising using a polishing liquid in which an abrasive material consisting of parts by weight is dispersed in a solvent.
研磨するに際し、焼結砥粒100重量部と破砕砥粒1〜
30重量部とからなる研磨材及び沈降防止剤であるポリ
ビニルアルコールが溶媒中に分散された研磨液を使用す
ることを特徴とするハードディスク用基板の研磨方法。(5) When polishing both sides of the surface of a ceramic substrate for a hard disk, 100 parts by weight of sintered abrasive grains and 1 to 10 parts of crushed abrasive grains are used.
1. A method for polishing a hard disk substrate, comprising using a polishing liquid in which an abrasive comprising 30 parts by weight and polyvinyl alcohol as an anti-settling agent are dispersed in a solvent.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63134478A JPH01304174A (en) | 1988-06-02 | 1988-06-02 | Polishing fluid and method of polishing hard disc base plate |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63134478A JPH01304174A (en) | 1988-06-02 | 1988-06-02 | Polishing fluid and method of polishing hard disc base plate |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH01304174A true JPH01304174A (en) | 1989-12-07 |
Family
ID=15129266
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP63134478A Pending JPH01304174A (en) | 1988-06-02 | 1988-06-02 | Polishing fluid and method of polishing hard disc base plate |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH01304174A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5691896A (en) * | 1995-08-15 | 1997-11-25 | Rosemount, Inc. | Field based process control system with auto-tuning |
US5812428A (en) * | 1995-09-22 | 1998-09-22 | Rosemount Inc. | Process controller having non-integrating control function and adaptive bias |
US5818714A (en) * | 1996-08-01 | 1998-10-06 | Rosemount, Inc. | Process control system with asymptotic auto-tuning |
WO2016103576A1 (en) * | 2014-12-26 | 2016-06-30 | 株式会社フジミインコーポレーテッド | Polishing composition, polishing method, and method for manufacturing ceramic component |
-
1988
- 1988-06-02 JP JP63134478A patent/JPH01304174A/en active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5691896A (en) * | 1995-08-15 | 1997-11-25 | Rosemount, Inc. | Field based process control system with auto-tuning |
US5812428A (en) * | 1995-09-22 | 1998-09-22 | Rosemount Inc. | Process controller having non-integrating control function and adaptive bias |
US5818714A (en) * | 1996-08-01 | 1998-10-06 | Rosemount, Inc. | Process control system with asymptotic auto-tuning |
WO2016103576A1 (en) * | 2014-12-26 | 2016-06-30 | 株式会社フジミインコーポレーテッド | Polishing composition, polishing method, and method for manufacturing ceramic component |
JP2016124915A (en) * | 2014-12-26 | 2016-07-11 | 株式会社フジミインコーポレーテッド | Polishing composition, polishing method and method for producing ceramic parts |
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