Electronics Manufacturing worked example

Reflow Dwell Time at 3.6% carrier and loading allowance: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop carrier and loading allowance to 3.6%, then walk the calculation through step by step. Estimate reflow oven dwell minutes from heated tunnel length, conveyor speed, and profile allowance.

The inputs for this scenario

  • Effective heated oven length: 240 in (held at the documented default)
  • Conveyor speed: 32 in / min (held at the documented default)
  • Carrier and loading allowance: 3.6 % (the input this scenario stresses; the baseline uses 5)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base oven dwell time = effective heated oven length รท conveyor speed.
  • Estimated reflow dwell time works out to 7.77 min at these inputs, and this is the headline figure for the scenario.
  • Base oven dwell time works out to 7.5 min at these inputs.
  • Carrier and loading allowance works out to 3.6 % at these inputs.
  • Conveyor speed works out to 32 in / min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where carrier and loading allowance sits at 5% and the headline result is 7.88 min, this scenario comes in 1.33% below the baseline at 7.77 min.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to carrier and loading allowance, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It gives total time in the heated tunnel, not the per-zone breakdown or time-above-liquidus; only an instrumented profile board confirms the actual joint thermal history.

Results at a glance

  • Estimated reflow dwell time: 7.77 min (headline result)
  • Base oven dwell time: 7.5 min
  • Carrier and loading allowance: 3.6 %
  • Conveyor speed: 32 in / min

Run it with your numbers

  • To rerun this with your own numbers, open the live Reflow Dwell Time calculator, set carrier and loading allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.