How do you calculate PCB assembly yield?

Divide the number of boards that pass inspection and test by the total boards started, then multiply by 100. With 8 passing out of 250 started, yield is 8 ÷ 250 × 100 = 3.2%.

What is a good PCB assembly yield for consumer IoT boards?

Mature SMT lines running consumer IoT boards typically hold first-pass yield above 98–99%. The 3.2% in this example signals a broken process or a mislabeled input, not a normal build.

What is first-pass yield vs final yield?

First-pass yield counts only boards that pass without any rework, while final yield includes boards recovered after touch-up. First-pass yield is the honest measure of process capability.

Why is my PCB yield gap to target so large?

The gap is your yield minus target. Here 3.2% − 95% gives a −91.8 point shortfall, meaning either the process is failing badly or the passing-count field was entered incorrectly.

Does this include rework and repaired boards?

No. Enter only boards that passed clean on the first pass. Counting reworked boards as good inflates the number and hides the real defect rate.

How many boards should I sample to trust the yield?

Use the full lot when possible. A 250-board population gives a reasonable read, but for low defect rates you may need thousands of boards to detect ppm-level issues.

Smart Home & Consumer IoT Hardware calculator

PCB Assembly Yield Calculator

PCB assembly yield is the percentage of printed circuit boards that clear reflow, AOI, and functional test on the first pass without rework. For smart home and consumer IoT hardware makers running high-mix SMT lines, it is the single clearest signal of solder paste quality, placement accuracy, and component sourcing health. Process engineers and SMT line leads watch it per build to catch tombstoning, cold joints, and BGA voiding before they become field returns. A yield that drifts below target usually means paste stencil aperture, oven profile, or reel quality needs attention.

What this calculator does

Estimate pcb assembly yield for smart home and consumer IoT hardware using production-ready inputs so teams can track KPI performance and decide whether corrective action is needed.
Use it when pcb assembly yield in smart home and consumer iot hardware needs a clean rate and gap-to-target you can put on a tier board.
It computes the share of boards that pass assembly and test on the first pass, then the gap in percentage points between that yield and your target.

Formula used

Pcb assembly yield rate = pcb assembly yield count ÷ total pcb assembly yield population × 100
Pcb assembly yield gap to target = pcb assembly yield rate - target pcb assembly yield rate

Inputs explained

Boards passing SMT & AOI inspection:
Boards started into the assembly line:
Target first-pass yield for this build:

How to use the result

Use it after each SMT run or shift to grade line health and decide whether a build needs process containment before shipping.
First-pass yield alone hides where losses occur — a low number tells you something is wrong but not whether it's paste, placement, reflow, or a bad component lot.

Current U.S. benchmarks

Global copper trades at $13,484 per tonne (IMF via FRED, May 2026), up 41.5% in a year, and U.S. industrial electricity averages 8.66 cents per kWh. Both feed electrified-hardware unit economics.
Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).

Common questions

How do you calculate PCB assembly yield? Divide the number of boards that pass inspection and test by the total boards started, then multiply by 100. With 8 passing out of 250 started, yield is 8 ÷ 250 × 100 = 3.2%.
What is a good PCB assembly yield for consumer IoT boards? Mature SMT lines running consumer IoT boards typically hold first-pass yield above 98–99%. The 3.2% in this example signals a broken process or a mislabeled input, not a normal build.
What is first-pass yield vs final yield? First-pass yield counts only boards that pass without any rework, while final yield includes boards recovered after touch-up. First-pass yield is the honest measure of process capability.
Why is my PCB yield gap to target so large? The gap is your yield minus target. Here 3.2% − 95% gives a −91.8 point shortfall, meaning either the process is failing badly or the passing-count field was entered incorrectly.
Does this include rework and repaired boards? No. Enter only boards that passed clean on the first pass. Counting reworked boards as good inflates the number and hides the real defect rate.

Last reviewed 2026-05-12.