Logitech WBS7 - Procedure for Wax Mounting with bulk Crystalbond Stick

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