How do you calculate hermetic seal yield?

Divide packages passing leak test by packages tested and multiply by 100. With 238 of 250 packages passing, yield is 95.2%.

What is a good hermetic seal yield for implantable electronics?

Mature implantable sealing lines typically target 98% or higher, with leading laser-weld processes running above 99%. The 95.2% in the example sits 2.8 points below a 98% target, signaling the weld process needs attention.

What does the yield gap to target tell me?

It is your current yield minus the target, in percentage points. A negative gap means you are below target. Here the gap is 2.8 points short of 98%, which on a 250-unit lot is several extra rejected packages per run.

What causes hermetic seal failures?

Common causes are weld voids or porosity, contamination at the seal interface, insufficient weld energy, lid-to-base misalignment, and braze flux residue. A drop in leak-test yield usually points back to one of these in the sealing or cleaning step.

Fine leak vs gross leak testing, which yield does this use?

This calculator uses the combined pass result, a package must pass both gross (bubble or pressure) and fine (helium mass spectrometry) leak tests to count as passing. Track yields separately as well to localize whether failures are large breaches or slow leaks.

Why track yield instead of just counting rejects?

Yield normalizes for lot size so you can compare runs and trend the process over time. Twelve rejects on a 250-unit lot is 95.2% yield, but the same twelve on a 500-unit lot would be 97.6%; yield makes the comparison fair.

Implantable Electronics & Neurodevices calculator

Hermetic Seal Yield Calculator

Hermetic seal yield is the percentage of implantable-electronics packages, the titanium or ceramic enclosures around pacemaker, neurostimulator, and cochlear-implant electronics, that pass fine and gross leak testing. Process and quality engineers in active implantable device manufacturing use it to monitor the laser, resistance, or braze welding step that creates the hermetic barrier, because a leaking seal lets body fluids reach the electronics and is a patient-safety failure, not just scrap. It matters because hermeticity is one of the most scrutinized characteristics in an ISO 13485 implantable line; yield trends here feed CAPA decisions, weld-parameter tuning, and lot disposition. Tracking the gap to a target yield turns a single test result into an actionable signal about whether the sealing process is in control.

What this calculator does

Calculate the pass rate for implantable device hermetic packages after helium leak testing or seal inspection.
Use it when quality or process engineering needs to compare hermetic package seal results against the release target for a pacemaker, neurostimulator, sensor, or feedthrough lot.
It computes hermetic seal yield as the share of tested packages that pass leak test, and the gap in points to your target yield.

Formula used

Hermetic seal yield = hermetic packages passing leak test ÷ hermetic packages tested × 100
Hermetic seal yield gap to target = hermetic seal yield - target hermetic seal yield

Inputs explained

Hermetic packages passing leak test:
Hermetic packages tested:
Target hermetic seal yield:

How to use the result

Use it for lot-level or run-level monitoring of the hermetic sealing step on an implantable or neurodevice line.
Pass/fail leak-test yield does not capture marginal seals that pass today but may degrade, so it should be read alongside leak-rate distribution and aging 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).
U.S. manufacturing runs at 75.6% of capacity with new factory orders at $657B per month (Federal Reserve and Census, May 2026).
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 hermetic seal yield? Divide packages passing leak test by packages tested and multiply by 100. With 238 of 250 packages passing, yield is 95.2%.
What is a good hermetic seal yield for implantable electronics? Mature implantable sealing lines typically target 98% or higher, with leading laser-weld processes running above 99%. The 95.2% in the example sits 2.8 points below a 98% target, signaling the weld process needs attention.
What does the yield gap to target tell me? It is your current yield minus the target, in percentage points. A negative gap means you are below target. Here the gap is 2.8 points short of 98%, which on a 250-unit lot is several extra rejected packages per run.
What causes hermetic seal failures? Common causes are weld voids or porosity, contamination at the seal interface, insufficient weld energy, lid-to-base misalignment, and braze flux residue. A drop in leak-test yield usually points back to one of these in the sealing or cleaning step.
Fine leak vs gross leak testing, which yield does this use? This calculator uses the combined pass result, a package must pass both gross (bubble or pressure) and fine (helium mass spectrometry) leak tests to count as passing. Track yields separately as well to localize whether failures are large breaches or slow leaks.

Last reviewed 2026-05-12.