Method of manufacturing disk drive device for reducing adhesive amount of particles, and disk drive device manufactured by the method

Abstract

In a method of manufacturing a disk drive device, a cleaning process and an assembly process are performed in succession in a clean room having a predetermined cleanness level. The cleaning process includes an alkali cleaning process, a first purified water cleaning process, a second purified water cleaning process, a spray cleaning process, a draining process and a drying process. In the first purified water cleaning process, purified water ultrasonic wave cleaning is sequentially performed on the base member of the disk drive device to be cleaned by using ultrasonic waves of frequencies of 40 kHz, 68 kHz and 132 kHz in purified water filled in a first purified water cleaning tank. The cleaned base member and other components having a predetermined cleanness level are assembled in the assembly process continuous from the cleaning process.

What is claimed is: 
     
         1 . A method of manufacturing a disk drive device comprising a base member, a bearing unit, a hub supported by the bearing unit so that the hub can rotate with respect to the base member, the method including a step of cleaning at least one component of the disk drive device, wherein the step of cleaning includes the steps of:
 subjecting said at least one component to an ultrasonic wave while transporting said at least one component in purified water; and   spraying a mixture of liquid and air on said at least one component,   the method further includes a step of assembling the disk drive device including said at least one component in a clean area which is continuously connected with an area in which the step of cleaning is performed, the clean area having a predetermined level of cleanliness or higher level of cleanliness.   
     
     
         2 . The method according to  claim 1 , wherein, in the step of spraying, the mixture of air and purified water particles with the diameter ranging from 20 micrometers to 80 micrometers is sprayed with a velocity ranging from 20 m/s to 80 m/s. 
     
     
         3 . The method according to  claim 1 , wherein, in the step of spraying, a suction port for recovering the mixture is provided at a position toward which at least a part of the mixture is directed after the mixture has collided with said at least one component. 
     
     
         4 . The method according to  claim 1 , wherein the step of cleaning includes an alkali cleaning in which said at least one component of the disk drive device is subjected to an ultrasonic wave in alkali ion water while being transported, prior to the step of subjecting. 
     
     
         5 . The method according to  claim 1 , wherein the clean area in the step of assembling has a positive pressure relative to the clean area in the step of cleaning. 
     
     
         6 . The method according to  claim 1 , wherein, in the step of subjecting, said at least one component is subjected to ultrasonic waves with two different frequencies. 
     
     
         7 . The method according to  claim 6 , wherein, in the step of subjecting, an ultrasonic wave used on the cleaning end side has a frequency higher than that of an ultrasonic wave used on the cleaning start side. 
     
     
         8 . The method according to  claim 1 , wherein the step of subjecting includes a step of hitting said at least one component with a jet flow of purified water. 
     
     
         9 . The method according to  claim 1 , wherein, in the step of cleaning, said at least one component of the disk drive device is transported while being provided with either a rotational movement or vibrational movement, or both, at least in a cleaning liquid. 
     
     
         10 . The method according to  claim 1 , wherein the step of cleaning includes a step of spraying clean air on said at least one component after it has passed the step of spraying the mixture. 
     
     
         11 . The method according to  claim 1 , wherein the step of cleaning includes a step of drying said at least one component, after it has passed the step of spraying the mixture, by hot air and a far-infrared heater. 
     
     
         12 . A method of manufacturing a disk drive device comprising a base member, a bearing unit, a hub supported by the bearing unit so that the hub can rotate with respect to the base member, the method including the steps of:
 subjecting at least one component of the disk drive device to an ultrasonic wave while transporting said at least one component in purified water;   spraying a mixture of liquid and air on said at least one component; and   assembling the disk drive device including said at least one component in a clean area having a predetermined level of cleanliness or higher level of cleanliness.   
     
     
         13 . The method according to  claim 12 , wherein, in the step of spraying, the mixture of the air and purified water particles with the diameter ranging from 20 micrometers to 80 micrometers is sprayed with a velocity ranging from 20 m/s to 80 m/s. 
     
     
         14 . The method according to  claim 12 , wherein, in the step of spraying, a suction port for recovering the mixture is provided at a position toward which at least a part of the mixture is directed after the mixture has collided with said at least one component. 
     
     
         15 . The method according to  claim 12 , further including a step of alkali cleaning in which said at least one component of the disk drive device is subjected to an ultrasonic wave in alkali ion water while being transported, prior to the step of subjecting. 
     
     
         16 . The method according to  claim 12 , wherein, in the step of subjecting, said at least one component is subjected to ultrasonic waves with two different frequencies. 
     
     
         17 . The method according to  claim 12 , further including a step of spraying clean air on said at least one component after it has passed the step of spraying the mixture. 
     
     
         18 . A method of manufacturing a disk drive device comprising a base member, a bearing unit, a hub supported by the bearing unit so that the hub can rotate with respect to the base member, the method including the steps of:
 spraying a mixture of liquid and air on at least one component of the disk drive device; and   assembling the disk drive device including said at least one component in a clean area having a predetermined level of cleanliness or higher level of cleanliness.   
     
     
         19 . The method according to  claim 18 , wherein, in the step of spraying, the mixture of the air and purified water particles with the diameter ranging from 20 micrometers to 80 micrometers is sprayed with a velocity ranging from 20 m/s to 80 m/s. 
     
     
         20 . The method according to  claim 18 , wherein, in the step of spraying, a suction port for recovering the mixture is provided at a position toward which at least a part of the mixture is directed after the mixture has collided with said at least one component.