Semiconductor Fab Equipment Manufacturing worked example

Vacuum Chamber Leak Rate at 68% target first-pass leak-test yield: a worked example

Suppose target first-pass leak-test yield falls to 68%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate vacuum chamber leak rate for semiconductor fab equipment manufacturing using production-ready inputs so teams can track KPI performance and decide whether corrective action is needed.

The inputs for this scenario

  • Chambers failing helium leak test: 8 count (held at the documented default)
  • Chambers leak-tested this build lot: 250 count (held at the documented default)
  • Target first-pass leak-test yield: 68 % (the input this scenario stresses; the baseline uses 95)

Working through the calculation

  • The calculation starts from the formula this tool documents: Vacuum chamber leak rate = vacuum chamber leak rate count ÷ total vacuum chamber leak rate population × 100.
  • Vacuum chamber leak rate works out to 3.2 % at these inputs, and this is the headline figure for the scenario.
  • Vacuum chamber leak rate gap to target works out to 64.8 points at these inputs.
  • Vacuum chamber leak rate count works out to 8 count at these inputs.
  • Total vacuum chamber leak rate population works out to 250 count at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where target first-pass leak-test yield sits at 95% and the headline result is 3.2 %, this scenario lands almost exactly on the baseline at 3.2 %.
  • It computes what percent of leak-tested chambers failed, and the point gap between that rate and your target first-pass yield. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Vacuum chamber leak rate: 3.2 % (headline result)
  • Vacuum chamber leak rate gap to target: 64.8 points
  • Vacuum chamber leak rate count: 8 count
  • Total vacuum chamber leak rate population: 250 count

Run it with your numbers

  • To rerun this with your own numbers, open the live Vacuum Chamber Leak Rate calculator, set target first-pass leak-test yield to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.