Bombing Leak Test
What is a Bombing Leak Test?
Bombing (helium bomb testing) is the trace gas method for finished, hermetically sealed parts with no fill port — implantable devices, MEMS, sealed relays, crystals. The parts are placed in a pressure vessel (“the bomb”) filled with helium at elevated pressure for a timed soak: if a part has a leak path, helium is forced inside it. The parts then move to a vacuum chamber where a mass spectrometer measures any helium bleeding back out — revealing and quantifying the leak with fine-leak sensitivity down to the 10⁻⁹–10⁻¹⁰ mbar·l/s range.
One nuance matters: a very large (gross) leak fills and empties quickly, so its helium can escape before the vacuum test — which is why bombing is always paired with a gross leak test, in the style of MIL-STD-883 and JEDEC fine/gross qualification. A Zaxis controller sequences both so every part gets full coverage. See all trace gas leak testing methods.
Here’s how it works:
- Bomb — sealed parts soak in a pressure vessel of helium at elevated pressure for a timed period; helium is forced into any part with a leak path.
- Transfer — parts are removed and surface helium is allowed to dissipate so it cannot mask the measurement.
- Evacuate — the part goes into a vacuum chamber and the chamber is pumped to hard vacuum.
- Measure — the mass spectrometer reads helium escaping from inside the part; a tight part shows only background.
- Judge — the fine-leak reading is compared to the reject limit for PASS/FAIL, and a companion gross leak test closes the large-leak blind spot.
Helium bombed into a leaker bleeds back out above the reject limit within seconds of reaching vacuum. Zaxis bombing test systems sequence soak, measurement, and gross leak automatically.
Sample Applications:
- Implantable medical devices — pacemakers, neurostimulators
- Hermetic MEMS, sensors & crystals
- Sealed relays & switches
- Optoelectronic & photonic packages
- Airbag igniters & pyrotechnic devices
- Hermetic connectors & feedthroughs
Qualifying sealed devices to a fine/gross leak spec? Contact Zaxis — our engineers will size the soak pressure, dwell, and measurement sequence for your standard.
Why Choose Bombing for Your Sealed Products
When a part leaves the line hermetically sealed, bombing is the method that can still prove it is tight — no port, no problem.
- The only trace gas method for sealed parts — no fill port or connection required
- Hard-vacuum sensitivity on finished devices — fine leaks to the 10⁻⁹–10⁻¹⁰ mbar·l/s range
- Batch throughput — an entire tray of parts soaks in one bomb cycle
- Standards-ready — supports MIL-STD-883 / JEDEC style fine & gross leak workflows
- Quantitative, audit-ready data — a recorded leak rate for every serial number
- Full coverage — paired gross leak testing closes the large-leak blind spot
Contact Zaxis Inc today to build the right bombing solution for your sealed product.
Suggested Leak Testers For Bombing
Helium leak detector for the post-bomb vacuum measurement — calibrated reject limits and a clear PASS/FAIL for every part.
Manages the helium side of the process — evacuate, purge, and charge the bombing vessel to soak pressure, repeatable every batch.
The 8″ modular platform that sequences bomb soak, vacuum measurement, and the paired gross leak test — with logged results for every part.
Bombing gives manufacturers of hermetically sealed devices a quantitative, standards-ready way to prove fine-leak integrity on the finished product — batch after batch. Zaxis builds complete bombing solutions — pressure vessel control, vacuum measurement, and the paired gross leak test — engineered as one integrated cell. Explore all trace gas leak testing methods or request a quote to get started.