JP2006092717A - Manufacturing method and apparatus for glass substrate for magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and an apparatus for a glass substrate for a magnetic recording medium capable of preventing a new defect generated by drying of a washing liquid at a substrate under treatment when a glass substrate is polished and then immersed in the washing liquid to be washed. <P>SOLUTION: A humidifier for humidifying the inner part of a washing device in which a washing vessel storing the washing liquid for immersing and washing the glass substrate after the glass substrate is polished using abrasive grains is provided and the inner part of the washing device is humidified to perform washing treatment operation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for manufacturing a glass substrate for a magnetic recording medium. More specifically, the present invention relates to a method for manufacturing a glass substrate for a magnetic recording medium and an apparatus therefor, comprising washing after the glass substrate is polished and before texture treatment.

  A glass substrate for use in a magnetic recording medium such as a hard disk is required to have a high degree of flatness and smoothness. Therefore, the glass substrate is subjected to a process for polishing the surface and a subsequent cleaning process. And the glass substrate for magnetic recording media obtained by this is attached | subjected to the texture process for surface treatment.

  In order to polish the glass substrate surface efficiently, abrasive grains such as cerium oxide and zirconium oxide are used as an abrasive, but there is a problem that these abrasive grains adhere to the glass surface. Therefore, it is necessary to remove the abrasive grains and glass shavings adhering in the polishing step by washing before the texture treatment.

  In the production of a glass substrate for a magnetic recording medium, it is known to wash the glass substrate with an organic acid such as oxalic acid, an aqueous solution of an inorganic acid such as hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, or a strong alkaline aqueous solution. (For example, see Patent Documents 1 to 3). In general, such cleaning is performed by feeding a large number of polished glass substrates (usually about 50 to 100) into a cleaning substrate carrier while sending clean air from above into a cleaning apparatus provided with a cleaning tank. It is performed by immersing in a cleaning liquid filled in the cleaning tank in a state and pulling up from the cleaning tank after a predetermined time. In this case, such a cleaning tank is usually provided with a plurality of tanks in the cleaning apparatus, and in some cases several to several tens of tanks, and the cleaning with the cleaning liquid and the water washing are usually repeated.

  However, in this case, it may take a considerable time for the substrate carrier to be lifted from one cleaning tank, transferred to the next cleaning tank, and immersed again, during which time the substrate surface dries and is contained in the liquid. In some cases, the particles of the foreign matter that have been aggregated may cause new defects on the surface of the substrate being processed.

JP 2004-2163 A JP 2000-31336 A JP 2000-30482 A

  The present invention provides a method for producing a glass substrate for a magnetic recording medium, which can prevent a new defect caused by drying of the cleaning liquid on the substrate being processed when the glass substrate is polished and then immersed in the cleaning liquid for cleaning. And to provide a device.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have determined that the surface of the substrate by humidifying the inside of the cleaning apparatus in which the cleaning tank for storing the cleaning liquid is installed when the glass substrate is immersed and cleaned with the cleaning liquid after polishing. The inventors have found that new defects can be prevented, and have completed the present invention based on this finding.

  Therefore, this invention consists of the following matters, for example.

  [1] After polishing a glass substrate with abrasive grains and then immersing it in a cleaning solution in a cleaning tank installed in the cleaning device, the cleaning device is humidified to perform a cleaning operation. A method for producing a glass substrate for a magnetic recording medium.

  [2] A humidifying device for humidifying the inside of the cleaning device provided with a cleaning tank containing a cleaning solution for cleaning by immersing the glass substrate in the cleaning solution after polishing the glass substrate is provided. An apparatus for manufacturing a glass substrate for a magnetic recording medium.

  According to the present invention, a glass substrate for a magnetic recording medium can be produced without causing new defects on the substrate surface when cleaning the polished glass substrate.

  Hereinafter, preferred embodiments of the present invention will be described. However, it is understood that these explanations are intended to specifically describe preferred examples for carrying out the present invention, and are not intended to limit the present invention in any way. I want to be.

  In the present invention, an ordinary plate glass is preferably used as the glass substrate.

  For polishing the surface of the glass substrate, abrasive grains such as cerium oxide, zirconium oxide, aluminum oxide, and silicon oxide can be used as an abrasive. Among these, from the viewpoint of polishing efficiency and the like, it is preferable to use polishing abrasive grains made of cerium oxide. The abrasive is preferably used as a suspension by suspending these abrasive grains in water.

  The polished glass substrate is then subjected to a cleaning process. Cleaning is generally performed by feeding a large number of polished glass substrates (usually about 50 to 100) onto a cleaning substrate carrier while sending clean air from above into a cleaning device with a cleaning tank. Is immersed in the cleaning liquid filled in the cleaning tank and pulled up from the cleaning tank after a predetermined time. In this case, such a cleaning tank is usually provided with a plurality of tanks in the cleaning apparatus, and in some cases several to several tens of tanks, and the cleaning with the cleaning liquid and the water washing are usually repeated.

  In the present invention, a humidifier is provided in such a cleaning device, and the inside of the cleaning device is humidified. As a result, the substrate surface is dried while the substrate carrier is pulled up from one cleaning tank, transferred to the next cleaning tank and dipped again, and foreign particles contained in the liquid are aggregated and processed. This prevents a new defect from occurring on the surface of the substrate inside.

  The humidification is preferably performed to such an extent that the humidity in the cleaning apparatus is 50 to 99%, and more preferably 70 to 90%.

  In the present invention, the glass substrate is preferably subjected to mechanical cleaning such as normal brush scrub cleaning before performing immersion cleaning with the cleaning liquid.

  Since the present invention makes it possible to manufacture a glass substrate for a magnetic recording medium without causing new defects on the substrate surface during immersion cleaning with a cleaning liquid after polishing the substrate, it is extremely useful industrially.

Claims (2)

  After the glass substrate is polished with abrasive grains, it is immersed in a cleaning liquid in a cleaning tank installed in the cleaning apparatus, and the cleaning process is performed by humidifying the cleaning apparatus. A method for producing a glass substrate for a recording medium.   A magnetic device characterized by providing a humidifying device for humidifying the inside of a cleaning device in which a cleaning tank containing a cleaning solution for cleaning by immersing the glass substrate in a cleaning solution after polishing the glass substrate. Equipment for manufacturing glass substrates for recording media.