How do you calculate die attach yield?

Divide good bonded dies by total dies attempted and multiply by 100. With 8 good out of 250, that is 8 ÷ 250 × 100 = 3.2%.

What is a good die attach yield?

Mature die-attach processes typically run 98-99.9%, since it's an early step whose losses cascade into all downstream value. A 3.2% result like the default indicates a serious excursion or a process still in bring-up.

What causes low die attach yield?

The usual culprits are epoxy voiding, die tilt, misplacement or offset, contamination, and cure-profile drift. X-ray voiding analysis and placement-accuracy checks usually isolate the dominant mode.

What does the gap-to-target mean here?

It is actual yield minus target in points. A 3.2% yield against a 95% target gives a 91.8-point gap, signaling the die-attach cell is far below where it needs to run.

Die attach yield vs assembly yield — how do they relate?

Die-attach yield covers just the bonding step; overall assembly yield multiplies it with wire bond, mold, and other steps. Because it's early, die-attach loss protects you from spending on units that would fail later.

Why catch die-attach failures early?

Every step after die-attach adds cost, so scrapping a bad bond here is far cheaper than discovering it after wire bond, mold, or final test. That's why die-attach yield is a leading indicator worth watching closely.

Semiconductor Advanced Packaging & Test calculator

Die Attach Yield Calculator

Die attach yield is the share of dies that bond correctly to the substrate or lead frame without voiding, tilt, misplacement, or bondline defects that fail inspection. Assembly process engineers, OSAT yield teams, and packaging quality owners watch it because die-attach is one of the earliest and most defect-prone steps in the package flow — a void under a power die or a tilted placement can compromise thermal path and reliability long before final test. Tracking yield against a target flags epoxy dispense, pick-and-place accuracy, or cure-profile drift early. Because every downstream step adds value on top of an attached die, a die-attach loss is cheaper to catch here than after wire bond or molding.

What this calculator does

Estimate die attach 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 die attach yield in semiconductor advanced packaging and test needs a clean rate and gap-to-target you can put on a tier board.
It computes the percentage of dies that pass die-attach inspection out of all attempted, plus the point gap above or below your target.

Formula used

Die attach yield rate = die attach yield count ÷ total die attach yield population × 100
Die attach yield gap to target = die attach yield rate - target die attach yield rate

Inputs explained

Dies attached passing bondline inspection:
Total dies attempted at die-attach:
Target die attach yield rate:

How to use the result

Use it after each die-attach lot or process change to confirm dispense, placement, and cure are holding your yield budget.
A single small lot can read noisy, and the percentage alone won't tell you whether losses come from voiding, tilt, or placement — pair it with X-ray and defect-mode data.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
The producer price index for plastic resins and materials stands at 319.371 (BLS, May 2026), up 19.5% 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 276.831 (BLS, May 2026), up 8.8% 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 die attach yield? Divide good bonded dies by total dies attempted and multiply by 100. With 8 good out of 250, that is 8 ÷ 250 × 100 = 3.2%.
What is a good die attach yield? Mature die-attach processes typically run 98-99.9%, since it's an early step whose losses cascade into all downstream value. A 3.2% result like the default indicates a serious excursion or a process still in bring-up.
What causes low die attach yield? The usual culprits are epoxy voiding, die tilt, misplacement or offset, contamination, and cure-profile drift. X-ray voiding analysis and placement-accuracy checks usually isolate the dominant mode.
What does the gap-to-target mean here? It is actual yield minus target in points. A 3.2% yield against a 95% target gives a 91.8-point gap, signaling the die-attach cell is far below where it needs to run.
Die attach yield vs assembly yield — how do they relate? Die-attach yield covers just the bonding step; overall assembly yield multiplies it with wire bond, mold, and other steps. Because it's early, die-attach loss protects you from spending on units that would fail later.

Last reviewed 2026-05-12.