Controlled particle deposition in drives and on media for thermal asperity studies

Abstract

An environmental chamber that can be used to test a device under test such as a hard disk drive. The environmental chamber may include an electronically controlled shutter that controls the flow of controlled particles from a second chamber to a first chamber. The controlled particles flow to a device under the test located within the first chamber. The shutter can be closed when a predetermined threshold of contaminants is detected by the environmental chamber. This two-chamber method provides a stable and uniform density (?) of particle environment around the drive.

What is claimed is:  
     
         1 . An environmental chamber to test a device under test, comprising: 
 a first chamber adapted to contain the device under test;    a second chamber that contains controlled particles;    a shutter located between said first and second chambers, said shutter being adapted to switch between an open position and a closed position; and,    a fan that is coupled to said second chamber and which generates a flow of air that moves the contaminant from said second chamber to said first chamber when said shutter is in an open position.    
     
     
         2 . The environmental chamber of  claim 1 , further comprising a controller that can switch said shutter between the open and closed positions.  
     
     
         3 . The environmental chamber of  claim 2 , further comprising a first chamber detector that is coupled to said controller and can detect a quantity of the contaminant within said first chamber.  
     
     
         4 . The environmental chamber of  claim 2 , further comprising a second chamber detector that is coupled to said controller and can detect a quantity of the contaminant within said second chamber.  
     
     
         5 . The environmental chamber of  claim 1 , further comprising a third chamber that contains said fan.  
     
     
         6 . The environmental chamber of  claim 5 , wherein said third chamber contains a deflector.  
     
     
         7 . The environmental chamber of  claim 1 , wherein said first chamber contains a deflector.  
     
     
         8 . The environmental chamber of  claim 1 , further comprising a tester that can be coupled to the device under test.  
     
     
         9 . The environmental chamber of  claim 1 , further comprising a thermal unit that is coupled to said first chamber.  
     
     
         10 . The environmental chamber of  claim 1 , further comprising a vibration table that can vibrate the device under test.  
     
     
         11 . An environmental chamber to test a device under test, comprising: 
 a first chamber adapted to contain the device under test;    a second chamber that contains a contaminant;    a shutter located between said first and second chambers, said shutter being adapted to switch between an open position and a closed position;    a fan that is coupled to said second chamber and which generates a flow of air that moves the contaminant from said second chamber to said first chamber when said shutter is in an open position;    a first chamber detector that can detect a quantity of the contaminant in said first chamber; and    a controller that is connected to said shutter, and said first chamber detector, said controller opens said shutter until said first chamber contains a predetermined quantity of contaminants.    
     
     
         12 . The environmental chamber of  claim 11 , further comprising a second chamber detector that can detect a quantity of contaminants in said second chamber.  
     
     
         13 . The environmental chamber of  claim 11 , further comprising a third chamber that contains said fan.  
     
     
         14 . The environmental chamber of  claim 13 , wherein said third chamber contains a deflector.  
     
     
         15 . The environmental chamber of  claim 11 , wherein said first chamber contains a deflector.  
     
     
         16 . The environmental chamber of  claim 11 , further comprising a tester that can be coupled to the device under test.  
     
     
         17 . A method for testing a hard disk drive, comprising: 
 placing a hard disk drive in a first chamber;    moving controlled particles from a second chamber to the first chamber; and,    testing the hard disk drive.    
     
     
         18 . The method of  claim 17 , further comprising opening a shutter to allow controlled particles to move from the first chamber to the second chamber, detecting a quantity of controlled particles within the first chamber and closing the shutter when there is a predetermined quantity of contaminants within the first chamber.  
     
     
         19 . The method of  claim 17 , further comprising varying the temperature of the hard disk drive.  
     
     
         20 . The method of  claim 17 , further comprising vibrating the hard disk drive.