Apparatus for cleaning glass substrate for use in information recording medium

Abstract

An apparatus for cleaning a glass substrate for use in information recording medium, having improved detergency, includes a plurality of gas feeding pipes, provided in a cleaning tank storing therein a cleaning fluid, for feeding air into the cleaning tank to generate bubbles of air in the cleaning fluid in which a glass substrate is immersed. The bubbles are brought into contact with the glass substrate while stirring the cleaning fluid to effectively remove deposits on the surface of the glass substrate.

What is claimed is:  
     
         1 . An apparatus for cleaning a glass substrate for use in information recording medium, the apparatus comprising: 
 a cleaning tank for storing therein a cleaning fluid; and    a gas feeding pipe, provided in the cleaning tank, for feeding a gas into the cleaning tank to generate bubbles of the gas in the cleaning fluid in which a glass substrate is immersed.    
     
     
         2 . The cleaning apparatus according to  claim 1 , wherein the cleaning tank has an inlet and an outlet for the cleaning fluid, the cleaning apparatus further comprising: 
 a circulation pipe connecting the inlet to the outlet;    a pump, provided in the circulation pipe, for circulating the cleaning fluid; and    a heater, provided on the circulation pipe, for heating the cleaning fluid being circulated.    
     
     
         3 . The cleaning apparatus according to  claim 2 , wherein the heater heats the cleaning fluid being circulated so that the temperature of the cleaning fluid stored in the cleaning tank is maintained at about 20 to 70° C.  
     
     
         4 . The cleaning apparatus according to  claim 2 , wherein the pump circulates the cleaning fluid at a rate of {fraction (1/20)} to {fraction (1/10)} of the capacity of the cleaning tank per minute.  
     
     
         5 . The cleaning apparatus according to  claim 2 , further comprising: 
 a filter, provided in the circulation pipe, for removing fine particles being present in the cleaning fluid and having a particle diameter equal to or greater than a predetermined particle diameter.    
     
     
         6 . The cleaning apparatus according to  claim 5 , wherein the filter removes fine particles having a particle diameter equal to greater than about 0.2 μm.  
     
     
         7 . The cleaning apparatus according to  claim 1 , wherein the bubbles have a diameter of about 1 to 40 mm.  
     
     
         8 . The cleaning apparatus according to  claim 1 , wherein the gas feeding pipe is one of a plurality of gas feeding pipes disposed in parallel on the bottom surface of the cleaning tank.  
     
     
         9 . The cleaning apparatus according to  claim 1 , wherein the rate of feeding the gas into the cleaning tank is about 30,000 to 110,000 cm 3  per minute.  
     
     
         10 . The cleaning apparatus according to  claim 1 , further comprising: 
 a filter, connected to the gas feeding pipe, for removing fine particles having a particle diameter equal to or greater than about 0.3 μm from the gas fed to the gas feeding pipe.    
     
     
         11 . The cleaning apparatus according to  claim 1 , wherein the cleaning fluid is water, and wherein the gas is air.  
     
     
         12 . A process for cleaning a glass substrate for use in information recording medium, comprising the steps of: 
 storing a cleaning fluid in a cleaning tank;    immersing a glass substrate in the cleaning fluid; and    feeding a gas into the cleaning tank to generate bubbles of the gas so that the bubbles are brought into contact with the glass substrate while stirring the cleaning fluid to remove deposits on the surface of the glass substrate.    
     
     
         13 . The process according to  claim 12 , further comprising the steps of: 
 circulating the cleaning fluid stored in the cleaning tank; and    heating the cleaning fluid being circulated.    
     
     
         14 . The process according to  claim 13 , wherein the heating step includes heating the cleaning fluid stored in the cleaning tank to about 20 to 70° C.  
     
     
         15 . The process according to  claim 13 , wherein the circulating step includes circulating the cleaning fluid at a rate of {fraction (1/20)} to {fraction (1/10)} of the capacity of the cleaning tank per minute.  
     
     
         16 . The process according to  claim 13 , further comprising the step of: 
 removing fine particles being present in the cleaning fluid being circulated and having a particle diameter equal to or greater than a predetermined particle diameter.    
     
     
         17 . The process according to  claim 16 , wherein the removing step comprises removing fine particles having a particle diameter equal to or greater than about 0.2 μm.  
     
     
         18 . The process according to  claim 12 , wherein the bubbles have a diameter of about 1 to 40 mm.  
     
     
         19 . The process according to  claim 12 , wherein the gas feeding pipe is one of a plurality of gas feeding pipes disposed in parallel on the bottom surface of the cleaning tank.  
     
     
         20 . The process according to  claim 12 , wherein the rate of feeding the gas into the cleaning tank is about 30,000 to 110,000 cm 3  per minute.  
     
     
         21 . The process according to  claim 12 , further comprising the step of: 
 removing fine particles having a particle diameter equal to or greater than about 0.3 μm from the gas fed to the gas feeding pipe.    
     
     
         22 . The process according to  claim 12 , wherein the cleaning fluid is water, and wherein the gas is air.