Integrated-Ultra%20High%20Density%20(iUHD)%20die%20thinning%20and%20handling%20Draper%20Labs%20IR

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Integrated-Ultra High Density (iUHD) die thinning
and handlingDraper Labs IRD 2007

• Motivation
• This project is driven by an increasing demand
  for vanishingly small electronic devices
  especially for intelligence operations.
• The use of thinner die directly translates into
  lower internal stresses within the chips.
• iUHD die thickness goal
• Forty microns (40 um) or less is the die
  thickness goal.
• Thinning is currently envisioned as a two step
  process.
• 1. Coarse thinning - Bulk silicon is removed
  from the back of each die using a lapping process
  with diamond slurry.
• 2. Fine thinning The remainder of silicon is
  removed using cmp to eliminate stress raising
  scratches and provide a mirror-like surface.
• Unique carrier fixture for die thinning is
  required
• The goal is to develop a thinning process that
  will allow dies to be thinned, inspected, and
  applied to the substrate as a group.

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Device Variables

• Die range in size from about 12 mm square to
  about 0.5 mm square.
• Die have unique topography and surface dielectric
  coating

• Common Defects
• Edge chips
• Sub-surface damage
• Scratches
• Curled/Wavy die
• Particulate embedded in die face