Method of Manufacturing Silicon Substrates for Magnetic Recording Medium, Silicon Substrate for Magnetic Recording Medium, Magnetic Recording Medium, and Magnetic Recording Apparatus

Abstract

A manufacturing method for silicon substrates for a magnetic recording medium has the steps of forming a stack body of a number of silicon substrates which are stacked via spacers therebetween, wherein each silicon substrate has a circular hole at a center of the substrate; immersing the stack body of the silicon substrates in a polishing liquid in which grains are suspended; and polishing inner peripheral end faces of the circular holes of the silicon substrates, wherein in polishing, a polishing brush contacts the end faces while performing a relative rotation between the end faces and the polishing brush, and the stack body of the silicon substrates is inverted during polishing. The step of polishing the inner peripheral end faces may be performed before inner and outer peripheries of the silicon substrate are subjected to chamfering. Preferably, the polishing brush is made of polyamide resin.

1 . A manufacturing method for silicon substrates for a magnetic recording medium, comprising the steps of: 
 forming a stack body of a number of silicon substrates which are stacked via spacers therebetween, wherein each silicon substrate has a circular hole at a center of the substrate;    immersing the stack body of the silicon substrates in a polishing liquid in which grains are suspended; and    polishing inner peripheral end faces of the circular holes of the silicon substrates, wherein in polishing, a polishing brush contacts the end faces while performing a relative rotation between the end faces and the polishing brush, and the stack body of the silicon substrates is inverted during polishing.    
   
   
       2 . The manufacturing method as claimed in  claim 1 , wherein the step of polishing the inner peripheral end faces is performed after inner and outer peripheries of the silicon substrate are subjected to chamfering.  
   
   
       3 . The manufacturing method as claimed in  claim 1 , wherein the polishing brush is made of polyamide resin.  
   
   
       4 . The manufacturing method as claimed in  claim 1 , wherein the difference between a maximum inner diameter and an minimum inner diameter of the circular hole of each silicon substrate of the stack body is 10 μm or less.  
   
   
       5 . The manufacturing method as claimed in  claim 1 , wherein the difference between a maximum inner diameter and an minimum inner diameter of the circular hole of each silicon substrate of the stack body is 4 μm or less.  
   
   
       6 . A silicon substrate for a magnetic recording medium, manufactured by a manufacturing method as claimed in  claim 1 .  
   
   
       7 . A magnetic recording medium made using a silicon substrate as claimed in  claim 6 , wherein at least a magnetic layer is formed on a main surface of the silicon substrate.  
   
   
       8 . A magnetic recording apparatus into which a magnetic recording medium as claimed in  claim 7  is mounted.