Removal of IPA from DI water in Marangoni Dryers

Marangoni Dryers use DI water and IPA to dry the high quality substrates such as silicon chips or hard disk drives. This talk was presented at the UPW Conference 2015 in Portland.

Transcript

1. IPA  Removal  in  UPW  from     Marangoni  Dryers   Azita  Yazdani,  P.E.  –  Exergy  Systems,  Inc.    
2. Project  Overview   •  Marangoni  dryers  are  a   popular  drying  process  in   high  purity  applicaHons   •  Wafers  submerged  in  water   are  slowly  passed  through  a   thin  layer  of  IPA  liquid   •  Wafers  are  dried  due  to  the   surface  tension  gradient   •  Marangoni  dryers   conHnuously  consume  UPW   and  generate  a  waste  stream   with  IPA    
3. SchemaHc  of  Marangoni  Drying  
4. A  Marangoni  Dryer  
5. Study  Overview   •  A  major  disk  drive  manufacturer  conducted   tests  to  qualify  if  the  recycled  effluent  could   be  treated  back  to  UPW  levels  and  reused  in   the  dryers   •  This  presentaHon  will  focus  on  the  removal   efficiencies  of  the  IPA  from  the  rinse  waters  so   the  water  can  be  recycled  back  to  the  dryer     •  Preliminary  pilot  scale  tesHng  was  conducted   using  Exergy  AEDI  and  Neotech  Aqua  TOC  UV    
6. Process  Layout  
7. Alpha  Test  Closed-­‐Loop  Diagram   30  Gallon   Tank   Misc.  Pre-­‐ treatment     On  the       TOC   UV   Feed  Water   Pre-­‐Made  Test   Batches   10%  reject  from  the  process   UPW  Recovered     AEDI  
8. Study  challenges   •  Due  to  the  site  restricHons,  the  tests  were  set  up  in   an  adjacent  area  to  the  cleanrooms  where  dryers   were  located   •  Batches  of  UPW/IPA  mixture  were  made  by   customer  on-­‐site  personnel  to  simulate  the  effluent   stream   •  The  IPA  tests  were  conducted  by  the  customer  and   the  data  was  recorded  and  provided  by  the  customer   •  Due  to  site  and  equipment  limitaHons,  the  test  were   limited  in  scope  
9. TOC    UV  Technology:     Key  Feature  Uniform  UV  DistribuHon   10  Ray  Tracing  in  3  In.  Chamber   100%  Dose  Assurance  
10. Single  Lamp  &  Single  Chamber     Lamp   Lamp   Lamp   Lamp   Lamp   Lamp   Lamp   Conven+onal  Chamber   Mul+ple  Lamps   w/  Baffles   Need  10x  Disinfec+on  Dose   Lamp   Highly  Reflec+ve  Reactor   Single  Chamber   •  Single  Chambers   •  Reduced  Annulus   •  No  Baffles   •  High  Hydroxyl  Genera+on   •  Need  3x  Disinfec+on  Dose  
11. Comparison  Data  –  Previous  Study   20% 30% 40% 50% 60% 70% 80% 90% 100% 0 1 2 3 4 5 6 7 8 9 % IPA Reduction Flow [Liter/min] 4 Units of Conventional Reactors vs 2 Units of Highly Reflective Reactors 4 x SL-10A 2 x UVS219T
12. Water  Recycling  Test-­‐  Set  up   •  The  made  up  test  water  was  filled  into  30-­‐ gallon  tank     •  IniHal  concentraHons  of  IPA  was  set  at  350   ppb     •  Exergy  AEDI  consists  of  proprietary   pretreatment  and  Exergy  AEDI   •  The  UV  system  was  added  to  provide   addiHonal  IPA  reducHon  capability    
13. Test  Runs   •  The  configuraHon  was  tested  over  a  period  of   3  months  with  various  configuraHons   •  Three  TOC  metrology  equipment  were  tested   –  each  with  varied  results   •  Some  tests  were  with  the  UV  on  or  off   •  The  customer  ran  and  managed  the  tests   •  The  data  shows  that  the  configuraHon  with   the  UV  on  was  the  most  effecHve  in  IPA   removal  
14. Different  Values  by  Different  TOC  Meters   0   50   100   150   200   250   300   350   400   JS3A   JS3A   JS3A   JS3A   JS3A   JS3A   JS3A   JS3A   JS3A   JS3A   JS3A   JS3A   TC609   TC609   TC609   TC609   TC609   TC609   TC609   TC609   TC609   TC609   TC609   DA31C   DA31C   DA31C   DA31C   DA31C   NCL818   NCL818   NCL818   NCL818   NCL818   NCL413   NCL413   NCL413   NCL413   TOC  (ppb)   Chemical  Solu+on   TOC  measured  Analy+cal  Equipment  A  vs.  B   •  Rinse  water  TOC  measurements  are  inconsistent  with  various  meter   •  TOC  measurement  are  impacted  by  the  amount  of  organic  acid  in  soluHon  
15. IPA  ReducHon   y  =  -­‐0.0007x  +  0.9009   R²  =  0.81361   0.0%   10.0%   20.0%   30.0%   40.0%   50.0%   60.0%   70.0%   80.0%   90.0%   100.0%   0   50   100   150   200   250   300   350   400   IPA  Removal  %   IPA  Concentra+on   IPA  Removal  with  UV  Treatment  0.4  GPM  by  IPA   Concentra+on     Removal  %-­‐TOC   Linear  (Removal  %-­‐TOC)   Ini+al     Concentra+on   Through  Filtra+on  Unit   UV  Treatment   AYer  UV      1  pass   Ini+al  Concentra+on     AYer  Pretreatment  
16. Flow  Rate  vs  IPA  ReducHon   95.7%   74.4%   69.70%   0.0%   20.0%   40.0%   60.0%   80.0%   100.0%   0.4  gpm   0.7  gpm   1  gpm   IPA  Percent  Reduc+on   UV  Flow  Rate   IPA  Reduc+on  with  Increasing  Flow  rates  
17. ObservaHons  and  Improvements   •  This  test  was  designed  for  a  0.5  gpm  flow   •  The  equipment  can  easily  be  scaled  for  larger   flow  streams   •  Depending  on  the  need,  IPA  removal  can  be   scaled:   – MulHple  passes     – VariaHon  in  configuraHon  to  enhance  treatment   (UV  and  Pretreatment)   – AddiHonal  treatment  elements  
18. Results   •  A  properly  engineered  system  with  adequate   UV  is  expected  to  reach  TOC<5ppb  -­‐  UPW   specs   •  The  IPA  levels  has  to  achieve  TOC  <  5  ppb  to   allow  reuse  in  this  applicaHon:   – A  reducHon  of  98.6%   •  Preliminary  results  are  promising:  Rinses  from   the  dryer  may  be  recycled  and  a  Marangoni   Dryer  maybe  closed-­‐looped