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Recommendations on Mounting

• The surface under the semiconductor contact surface should be flat to 
  within 25.4 mm per 25.4 mm and have a surface finish of 0.03mm or 
  less and must have the heatsink surface free of grease and oxide. The
  extruded surface of the aluminum heatsink should be machined before
  final assembly.

• Good thermal contact between the semiconductor device and the
  heatsink is obtained through the use of a torque wrench. We would like 
  to remember that excessive torque may damage the device
  permanently.

• When the stud type device is going to be used in a threaded hole in an
  aluminum heatsink it is necessary to be very careful about the
  perpendicularity between the surface of the heatsink and the thread. 
  The limit for this non perpendicularity must be smaller than 0.03 mm. It
  is also recommended that the fin hole should be chamfered.

• It is recommended to use always thermal grease between the stud
  device surface and the heatsink surface.

• If the hole is punched, the fin should be subsequently blanked. If the
  hole is drilled, the burr should be carefully removed.