Semiconductor Cleanroom Downtime Cost Calculator

Estimate the total financial hit from a cleanroom outage by combining lost wafer output, contribution margin per wafer, scrap losses, and any insurance recovery. The output shows the residual loss after reimbursements so operations, finance, and risk teams can plan contingencies.

Typical wafer starts or completions each hour before the disruption.
Net margin per wafer after variable costs and scrap allowances.
Total hours the cleanroom or tool is unable to produce wafers.
Share of wafers ruined mid-process because of the downtime event.
Optional — defaults to no recovery

Operational planning tool — validate assumptions with fab finance and risk teams before reporting losses.

Examples

  • 280 wafers/hour, $145.00 margin, 6 hours downtime, 18.0% scrap, no recovery ⇒ $287,448.00 impact
  • 350 wafers/hour, $162.00 margin, 4 hours downtime, 12.0% scrap, 30% recovery ⇒ $177,811.20 impact

FAQ

How can I include cascading tool downtime?

Multiply downtime hours by the number of dependent steps affected or run the calculator separately for each toolset to sum the results.

What if scrap costs differ from contribution margin?

Replace the margin per wafer with the appropriate scrap cost per wafer so the calculation mirrors your accounting method.

Does this account for restart or cleaning labor?

No. Add those expenses to the final impact manually or adjust the contribution margin input to include the extra labor burden.

What if insurance only covers scrap or only lost throughput?

Run the calculator twice — once for throughput loss and once for scrap loss — and apply separate recovery percentages to model partial reimbursements.

Additional Information

  • Lost margin equals wafers per hour multiplied by downtime hours and contribution margin per wafer.
  • Scrap losses account for wafers already in process during the outage using the same margin assumption.
  • Insurance recovery percentage reduces the gross impact after all losses are summed.
  • If recovery exceeds the loss, the result bottoms at $0.00 because the percentage cannot create a gain.

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