Semiconductor Advanced Packaging & Test worked example

Wafer Sort Capacity at 99% expected wafer sort prober uptime: a worked example

What does the result look like when expected wafer sort prober uptime reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when wafer sort capacity in semiconductor advanced packaging and test is being asked to take on more work and you need to know if there is room.

The inputs for this scenario

  • Wafer sort dies tested per prober cycle: 4 units / cycle (unchanged)
  • Available wafer sort prober cycles: 480 cycles (unchanged)
  • Expected wafer sort prober uptime: 99 % (raised for this scenario; the documented default is 90)
  • Expected wafer sort first-pass yield: 97 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross wafer sort capacity = wafer sort capacity output per cycle × available wafer sort capacity cycles) to the inputs above produces each figure below.
  • At this operating point the engine returns 1,844 units for good wafer sort capacity, the number this scenario is built around.
  • At this operating point the engine returns 1,920 units for gross wafer sort capacity.
  • At this operating point the engine returns 19.2 units for wafer sort capacity downtime loss.
  • At this operating point the engine returns 57.02 units for wafer sort capacity yield loss.

How this compares with the baseline

  • Against the tool's baseline example, where expected wafer sort prober uptime sits at 90% and the headline result is 1,676 units, this scenario comes in 10% above the baseline at 1,844 units.
  • A figure at this level is achievable when expected wafer sort prober uptime is genuinely sustained, not just peaked for a shift. It assumes a single steady throughput and yield rate; it does not model index-time variation, retest loops, wafer-to-wafer yield spread, or probe-card touchdown limits.

Results at a glance

  • Good wafer sort capacity: 1,844 units (headline result)
  • Gross wafer sort capacity: 1,920 units
  • Wafer sort capacity downtime loss: 19.2 units
  • Wafer sort capacity yield loss: 57.02 units

Run it with your numbers

  • Every input above is editable in the live Wafer Sort Capacity calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.