How do you calculate flip chip yield?

Divide good units by total assembled units and multiply by 100. With 245 good units out of 250, yield is 98%.

What is the gap to target?

It is yield minus your target. Here 98% against a 95% target leaves 3 points of headroom, a lot comfortably above its release threshold.

What is a good flip chip yield?

Mature flip-chip lines run well above 99% at package assembly; the example's 98% is solid production territory with room to push. A single-digit yield, by contrast, would indicate a gross process or test-escape problem.

Why is my flip chip yield so low?

Common causes of yield loss are solder-bump non-wets, bridging from excess paste, warpage-driven opens, and underfill delamination. At the example's 98%, chase the residual 2% by defect Pareto rather than suspecting a systemic fault.

Flip chip yield vs. bump yield: what's the difference?

Bump yield scores the bumping step alone; this metric scores the assembled package after reflow and test, so it captures joining and underfill defects bump yield cannot.

Does the target field change the yield number?

No, the target only sets the gap. Yield itself is purely good over total; the target defines how far short you are of the goal.

Semiconductor Advanced Packaging & Test calculator

Flip Chip Yield Calculator

Flip Chip Yield measures the fraction of flip-chip assemblies that pass after bump, reflow, and interconnect test, then compares it against your target. Yield engineers and OSAT process teams use it to gauge how well solder-bump joining, underfill, and reflow are performing and how far short of goal a lot fell. Because flip-chip defects like non-wets, bridging, and open bumps are expensive at package level, tracking yield per lot is central to ramp readiness. It turns a good-unit count and population into a clean percentage plus a gap-to-target figure.

What this calculator does

Estimate flip chip yield for semiconductor advanced packaging and test using production-ready inputs so teams can track KPI performance and decide whether corrective action is needed.
Use it when flip chip yield in semiconductor advanced packaging and test needs a clean rate and gap-to-target you can put on a tier board.
It computes flip chip yield as good units over total assembled, times 100, and the point gap to your target yield.

Formula used

Flip chip yield rate = flip chip yield count ÷ total flip chip yield population × 100
Flip chip yield gap to target = target flip chip yield rate − flip chip yield rate (positive = below target)

Inputs explained

Good flip chip units passing:
Total flip chip units assembled:
Target flip chip yield:

How to use the result

Use it at end of line or after interconnect test to score a lot and quantify how far it sits below the yield goal.
A single pass/fail ratio hides the defect Pareto; a low number tells you there is a problem but not whether it is bump bridging, non-wet, or underfill voiding.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 542.853 (BLS, Jul 2026), up 52.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,543 per tonne (IMF via FRED, Jul 2026).
The producer price index for plastic resins and materials stands at 292.875 (BLS, Jul 2026), up 10.7% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The producer price index for paperboard and containers stands at 283.012 (BLS, Jul 2026), up 10.4% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 11,261 computer and electronic products establishments employing about 815,443 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate flip chip yield? Divide good units by total assembled units and multiply by 100. With 245 good units out of 250, yield is 98%.
What is the gap to target? It is yield minus your target. Here 98% against a 95% target leaves 3 points of headroom, a lot comfortably above its release threshold.
What is a good flip chip yield? Mature flip-chip lines run well above 99% at package assembly; the example's 98% is solid production territory with room to push. A single-digit yield, by contrast, would indicate a gross process or test-escape problem.
Why is my flip chip yield so low? Common causes of yield loss are solder-bump non-wets, bridging from excess paste, warpage-driven opens, and underfill delamination. At the example's 98%, chase the residual 2% by defect Pareto rather than suspecting a systemic fault.
Flip chip yield vs. bump yield: what's the difference? Bump yield scores the bumping step alone; this metric scores the assembled package after reflow and test, so it captures joining and underfill defects bump yield cannot.

Last reviewed 2026-08-12.