Technical Support Services 

Heating Ventilation & Air Conditioning System
   

Heating, Ventilation & Air-Conditioning System (HVAC)
     
 

The HVAC System is the backbone of the Facility in maintaining environmental parameters in the Clean Rooms.  Chillers, Volume Controlled Vane Axial Recirculating Air Handlers, Fresh Air Make-up units etc. working in tandem and monitored and controlled by Facilities Control and Monitoring System meet Temperature (20+ 0.5°C), Humidity (40+2.5%), Pressurization (2-3 mm WC) requirements of the Clean Rooms.
       
   


Four Centrifugal Chilling Machines of 550 TR each provide chilled water (medium temperature = 7°C) to 16 RAH (total capacity = 900 K cfm) in the wafer Fab as well as to the AHUs installed in Test & Assembly and other laboratory/office areas.  The Chilled Water requirement for Make-up Air Unit (capacity: 50K cfm), is further augmented with 3 nos. Reciprocating Chillers (110 TR each) which provide low temperature chilled water (3.3°C) to maintain the required humidity conditions inside the Clean Rooms.


Sensors and transmitter mounted in the Clean Rooms provide real time data of actual inside conditions to the microprocessor based controllers which in turn drive various pneumatically controlled HVAC drives.  Redundancy is built in the system to ensure required environmental conditions on a 24x7 basis.


Reciprocating Chillers -110 TR each
   

 
 

Exhaust System
     
   

A centralized exhaust system connected to the process tools removes acid/toxic and solvent exhausts. The acid/toxic exhaust system has a capacity of 40K cfm and is removed in SS ducts while the solvent exhaust of 6K cfm capacity is removed in MS ducts.


The fan static is 244 mmWC for Acid/Toxic exhaust and 144 mmWC for solvent exhaust while at each tool 25 mmWC of static is maintained.  The exhaust is suitably compensated with treated fresh air and positive pressure maintained inside the Clean Rooms.


The exhaust system runs on 24x7 basis and is backed by emergency generators.
    Central stack after wet scrubber
 
Other utilities
 

 

  
 













Compressed Dry Air (CDA)
Process tool requirement of CDA is met through two compressors of 300 cfm each with drying units capable of delivering clean dry air with -73°C dew point.  The distribution is through copper piping. The system is provided with back-up units given the criticality of the utility for the process tools


 Process Cooling Water (PCW)

Heat transfer from the process tools is mainly done by Process Cooling Water System to reduce the A/C load.  The system backed by emergency power has overall capability of producing PCW of 200 gpm at 18.5°C and distributed through SS piping.


 Process Vacuum

 Vacuum for process tool is catered through a centralized vacuum system capable of attaining 150 cfm, –29” Hg vacuum. A 100% capacity vacuum pump is provided as on-line standby unit.