STP-301/451 Series Instruction Manual 
 
11-12
Troubleshooting 
11.3.5 Overhaul 
The recommended maintenance intervals for different process applications are tabulated 
below: 
Process Period  Remarks 
Metal Etch  1 year  Ensure that TMS (Temperature Management 
System) is fitted and operational to prevent 
accumulation of by-product deposition in the 
pump. 
Other Etch 
Processes 
2 years   
Etching
*1
 
It is recommended to change the pump rotor after 5 years due to accumulated wear of 
the protective plating material 
Other semiconductor 
process 
2 years  Processes resulting in accumulation of deposits in 
the pump will require more frequent service. 
Clean applications 
(Only vacuum pumping) 
5 years   
Other use  (2 years)  Dependent on application, contact Edwards. 
 
◇  The touch down bearing inside the STP pump will be worn out after a number of full 
speed touch downs. 
 
The costs of replacing parts that need to be replaced because of deterioration or abrasion will 
be at your own charge. 
When overhaul of the STP pump or the STP control unit is needed, contact Service office. 
 
  
 
*1
  “Etching” includes semiconductor etching and LCD etching.