CN1279137C - Grinding liquid used for grinding back surface of storage hard disk magnetic head - Google Patents

Abstract

The invention discloses a grinding liquid used for grinding the back surface of a magnetic head of a memory hard disk, belonging to the technical field of surface superfine grinding. The grinding liquid contains the following components: mineral oil of eleven-carbon to thirteen-carbon alkanes, oily agent, diamond single crystal superfine powder, anti-oxidation and anti-corrosion agent, non-ionic surfactant, defoamer and antistatic agent, The weight ratio of each component is: alkane mineral oil: 50-94.79%; oily agent: 5-35%; diamond superfine powder: 0.01%-5%; anti-oxidant preservative: 0.02-0.5%; Surfactant: 0.1-5%; defoamer: 0.03-1.5%; antistatic agent: 0.05-3.0%. The use of the grinding liquid can reduce the cost, improve the work efficiency and improve the surface grinding precision, the surface has no scratches after grinding, the surface residual stress is low, and the surface roughness is 0.3-0.4 nanometers.

Description

A kind of abrasive liquid used for grinding the back of magnetic head of memory hard disk

technical field

The invention relates to a grinding liquid used for grinding the back surface of a magnetic head of a memory hard disk, and belongs to the technical field of surface ultrafine grinding.

Background technique

The surface quality of memory hard disk heads is the bottleneck that limits the capacity and storage density of memory hard disks. In order to improve the surface quality of the magnetic head, many people have conducted a lot of research. The current research mainly focuses on the superfine grinding and polishing of the front side of the magnetic head, while the research on the back side of the magnetic head is rarely involved. The surface quality of the back of the magnetic head is very important to eliminate the stress concentration phenomenon of the magnetic head and the subsequent processing quality of the magnetic head. At present, the grinding liquid on the back of the magnetic head is the same as that on the front of the magnetic head. The grinding liquid composed of nano-diamond powder or diamond polycrystalline ultrafine powder and oily medium is used. On the one hand, it is expensive, and on the other hand, the grinding rate is very low.

Contents of the invention

The object of the present invention is to provide a kind of diamond powder particle size is micron grade abrasive liquid, can reduce product surface roughness to nanoscale level, can be used in the grinding of memory hard disk magnetic head backside, the magnetic head surface after grinding has no scratches, the surface The roughness is 0.3-0.4nm, and at the same time, the residual stress on the surface of the magnetic head after grinding is small, the grinding efficiency is high, and the cost is low.

The magnetic head back grinding liquid of the present invention contains alkane mineral oil, oily agent, diamond powder, anti-oxidation anticorrosion agent, nonionic surfactant, defoamer and antistatic agent, and described alkane mineral oil is carbon eleven Any one of normal paraffin mineral oils to carbon thirteen, isoparaffin mineral oils; the oily agent is pentaerythritol esters in synthetic oils, polyalpha-olefins, rapeseed oil in natural refined vegetable oils, castor Any one in sesame oil; the described diamond powder is a diamond single crystal superfine powder, and its particle average size accounts for more than 95% in 0.1～0.2 μ m; Phenolic anti-oxidant preservative T501, combined with a small amount of benzotriazole derivative anti-oxidant preservative to increase its anti-oxidative synergistic effect and reduce the amount of T501, or use high-temperature antioxidant liquid mixed with dialkyl diphenylamine; Described nonionic surfactant can adopt any one in polyoxyethylene sorbitan monooleate, sorbitan monooleate, fatty alcohol polyoxyethylene ether; Described defoamer can be Adopt any one in the 889D non-silicon defoamer of Lubrizol Company, the IRGALUBE AF1 liquid ester polymer defoamer produced by Ciba Company; Described antistatic agent is selected N for use, N-ethylene diester amide, nonylphenol Any of polyoxyethylene ethers.

The weight proportion of each described component is as follows:

Alkane mineral oil 50～94.79%

  Oil agent 5～35%

  Superfine diamond powder 0.01%～5%

  Antioxidant preservative 0.02～0.5%

   Non-ionic surfactant 0.1～5%

  Defoamer 0.03～1.5%

  Antistatic agent 0.05～3.0%

The grinding liquid particles prepared by the invention have uniform distribution and good dispersion stability, and are used in the field polishing of the back of the computer magnetic head. The surface roughness after polishing is 0.3-0.4nm measured by an atomic force microscope, and the surface is very smooth. During the polishing process, hydrocarbon mineral oil and synthetic oil or natural refined vegetable oil can fully cool and lubricate, so that the back of the computer magnetic head can achieve the required processing accuracy in a short time.

Features of the present invention:

The grinding liquid of the present invention can be used for grinding the back of the magnetic head of the memory hard disk, or the grinding of the metal or non-metallic surface similar to the back of the magnetic head. In order to ensure a relatively high grinding rate, no scratches and black spots on the surface, and no excessive residual stress after grinding, the grinding liquid has a reasonable viscosity, and 5-35% of the viscosity index is added to the components to compare High synthetic oil or natural vegetable oil makes the abrasive have a relatively high viscosity index. During the grinding process, it will not cause insufficient lubrication due to the increase in temperature and decrease in viscosity; at the same time, the grinding liquid uses diamond single crystal ultrafine powder, which The price is low, and the surface of the crystal is relatively sharp, which is conducive to improving the grinding rate. The abrasive liquid is used for ultra-fine grinding on the back of the memory hard disk magnetic head to obtain a high-quality surface, and it can also be used on metal or non-metallic surfaces that require a high degree of finish similar to the back of the hard disk magnetic head.

Detailed ways:

Embodiment one: get single crystal diamond superfine powder 0.5g, polyoxyethylene (20) sorbitan monooleate nonionic surfactant 2g, pentaerythritol ester 60g, carbon 12 n-paraffin mineral oil 240g, di-tert-butyl 1 g of p-cresol anti-oxidant preservative, 0.1 g of benzotriazole derivative anti-oxidant preservative, 1 g of 889D non-silicon antifoaming agent of Lubrizol Company, 1 g of N, N-ethylene diester amide antistatic agent, fully mixed to make It becomes a suspension-like grinding liquid. The back of the magnetic head of the computer is ground with the abrasive liquid, and the surface roughness of the back of the magnetic head can reach 0.3-0.4nm.

Embodiment 2: Take 0.8g of single crystal diamond superfine powder, 2g of fatty alcohol polyoxyethylene ether nonionic surfactant, 80g of polyalphaolefin, 220g of carbon 13 isoparaffin mineral oil, di-tert-butyl p-cresol antioxidant Preservative 1.5g, benzotriazole derivative anti-oxidant preservative 0.1g, Lubrizol 889D non-silicon antifoaming agent 1g, N, N-ethylene diester amide antistatic agent 1g, mix well to make it into a suspension Slurry. The back of the magnetic head of the computer is ground with the abrasive liquid, and the surface roughness of the back of the magnetic head can reach 0.3-0.4nm.

Embodiment three: get single crystal diamond superfine powder 0.6g, sorbitan monooleate nonionic surfactant 2g, natural refined rapeseed oil 50g, carbon 13 n-paraffin mineral oil 250g, high temperature antioxidant liquid mixing two Alkyl diphenylamine 1g, IRGALUBEAF1 liquid ester polymer defoamer 1g, nonylphenol polyoxyethylene ether 1g, mix well to make it into a suspension-like grinding liquid. The back of the magnetic head of the computer is ground with the abrasive liquid, and the surface roughness of the back of the magnetic head can reach 0.3-0.4nm.

Embodiment 4: Get 0.8g of single crystal diamond superfine powder, 2g of fatty alcohol polyoxyethylene ether nonionic surfactant, 30g of natural refined castor oil, 270g of carbon 11 isomeric alkane mineral oil, di-tert-butyl p-cresol antioxidant Preservative 1.5g, benzotriazole derivative anti-oxidant preservative 0.1g, Lubrizol 889D non-silicon antifoaming agent 1g, N, N-ethylene diester amide antistatic agent 1g, mix well to make it into a suspension Slurry.

Claims (1)

1. a lapping liquid that is used for grinding back surface of storage hard disk magnetic head contains bortz powder, antioxidant preservative, nonionic surface active agent, defoamer and static inhibitor, it is characterized in that still containing the mineral oil and the oiliness improver of alkane; Any that described alkane mineral oil is carbon 11 in the alkane mineral oil of the normal paraffin mineral oil of carbon 13 and isomery; Described oiliness improver is rapeseed oil, in the Viscotrol C any in the pentaerythritol ester, poly-alpha olefins, natural exquisite vegetables oil in the synthetic oil; Described bortz powder is that diameter Distribution is the diamond single crystal body of 0.1～0.2 μ m; Described antioxidant preservative can be ditertbutylparacresol antioxidant preservative T501, and the 124 Triazole derivative antioxidant preservative that is equipped with trace is to increase in its antioxygen synergism, the high-temperature antioxidant liquid mixing dialkyl diphenylamine any; Described nonionic surface active agent can adopt any in polyoxyethylene 20 sorbitan monooleate, sorbitan mono-oleic acid ester, the fatty alcohol-polyoxyethylene ether; Described defoamer can adopt any in the IRGALUBEAF 1 liquid ester polymkeric substance defoamer that the 889D non-silicon defoaming agent, Ciba company of Lubrizol company produce; Described static inhibitor can be selected N for use, any in N-ethylene dibasic acid esters acid amides, the polyoxyethylene nonylphenol ether,

The weight proportion of described each component is as follows:

The mineral oil 50～94.79% of alkane

Oiliness improver 5～35%

Diamond super-fine powder 0.01%～5%

Antioxidant preservative 0.02～0.5%

Nonionic surface active agent 0.1～5%

Defoamer 0.03～1.5%

Static inhibitor 0.05～3.0%.