Logitech WBS7 - Procedure for Wax Mounting with bulk Crystalbond Stick

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Contributed by Miguel Daal, Mazin Group  -- 2018-04-24

Procedure for wax-mounting a 100mm Silicon wafer to another 100mm silicon carrier wafer, using the Logitech WBS7 Wafer Bonder.

  • Cover Hotplate surface with tinfoil, heat hotplate to 120°C. (Keep flammable solvents away!)
  • Place 4" polished handle wafer on hotplate.
  • Apply wax to center of wafer only, approximately 2-inch diameter size puddle of crystal bond wax directly from the crystalbond stick.
    • For mounting a 4-inch wafer, you need a good amount of wax to ensure coverage to wafer edges, eg.2-3mm thick.
    • Then remove wafer from hotplate. and cool. 
  • Open Logitech Bonder chamber:
    • Unscrew clamp until higher than clamp arm,
    • Swing front of clamp arm to the left (Difficult to disengage),
    • Lift bonder lid (also takes some force to open - ignore vacuum reading on digital display)
  • On the glass plate of the Logitech bonder:
    • Align work wafer on top of handle wafer placed.
    • Align the two wafers' flats.  
  • Place 6" piece of filter paper on top of work wafer.
  • Turn on Logitech bonder power (bottom right of machine chassis)
  • Close and lock Logitech bonder hatch.
  • On front panel of  Logitech bonder, confirm that Applied Pressure gauge is set to 5 psi.
  • Enter the process settings:
    • [setup] -> [Temp]
      • Bonding: 120°C      
      • Endpoint: 65°C
      • Offset: 20°C           
      • Units: C
    • [setup] -> [Vac Thres]
      • Proceed if Below: 2.4E+01 mBar
      • Abort if Below: 3.2E+01 mBar
    • [setup] -> [Process Control]
      • Process: Heat + Outgas
      • Soak: 5min
      • Bond: 15min
      • O.G. Limit: 20min
      • P.P. del: 1min
    • [Setup] -> [Heads]
      • Head 1 On
  • Start Process: [Process] -> [Start]
  • Process takes about 45min
    • Unload when it displays Status: Ready
  • If wax leaked onto the glass plate: remove glass plate and clean with Acetone+Wipe.
  • Turn off Logitech bonder (bottom right of machine chassis)
    • Close lid and clamp
  • Clean excess wax off your wafer using the POLOS Spinners, and an Acetone squirt bottle, followed by ISO & N2 dry (run both sides of the wafer).