The Advanced Packaging Summit 2026, held in July, adopted the theme “Packaging the Future of AI – From Silicon to Photon” — a signal that the industry’s next performance leap is optical. As AI clusters exhaust electrical I/O bandwidth and power budgets, co-packaged optics (CPO) — putting optical engines directly inside the chip package — has moved from research to roadmap.
CPO is a packaging story, but it is also a sealing story. Laser sources, photonic dies and fiber arrays inside a package create requirements that traditional electronics packaging never faced: hermeticity, cleanliness, and controlled atmospheres. For vacuum component manufacturers, CPO is where precision sealing technology meets the AI boom.
Why CPO Modules Need Hermetic Sealing
- Laser reliability: semiconductor lasers degrade when exposed to moisture and oxygen. They must live in hermetic (sealed) environments — often with dry nitrogen or inert fill — to meet telecom-grade reliability targets.
- Photonic performance: contaminants on waveguides and gratings change coupling efficiency. Cleanliness requirements approach those of MEMS and optical components.
- Fiber feedthroughs: light must enter and exit the package through fiber feedthroughs — glass-to-metal seals and fiber arrays whose leak integrity protects the whole module.
- Thermal management: lasers generate heat; active cooling paths cross the package boundary, creating additional sealing interfaces.
Where Vacuum-Grade Hardware Appears in CPO Production
1. Hermetic fiber feedthroughs
Fiber arrays crossing a package wall must seal while preserving sub-micron alignment. The same metal-sealing discipline used in vacuum feedthroughs applies — helium leak testing, clean assembly, thermal-cycle survival.
2. Sealed test and burn-in chambers
Before modules ship, they are burned in under controlled atmosphere. Test chambers use bellows-sealed doors, feedthroughs for RF and fiber, and precise atmosphere control — mini vacuum systems in production.
3. Bellows in optical alignment equipment
Active alignment of fibers to photonic dies happens on stages that often operate in clean nitrogen or vacuum environments; edge welded bellows protect the motion mechanisms while sealing the environment.
Engineering Notes for CPO Hardware
- Hermeticity targets: package-level leak rates typically ≤ 1×10-8 mbar·L/s; components should be tested tighter.
- Materials: kovar and glass-matched alloys dominate optics sealing; stainless and Inconel appear in tooling and chambers.
- Cleanliness: organic contamination kills laser life — parts must be solvent-cleaned, baked, and handled in cleanroom conditions.
- Thermal cycling: modules cycle from assembly temperature to operating temperature continuously; seals and bellows must survive thousands of cycles.
Alpha Technology’s Sealing Expertise
Alpha Technology brings the vacuum industry’s sealing discipline to CPO and photonics hardware: custom edge welded bellows, metal-sealed feedthroughs, and cleanroom-assembled test chamber components — all helium leak tested and documented. For help selecting materials under thermal cycling, see the material guide; for envelope and stroke design, the design guide.
FAQ
What is co-packaged optics (CPO)?
Placing optical engines — lasers, modulators, photonic integrated circuits — directly inside or adjacent to the chip package to move data optically instead of electrically.
Why can’t lasers just be encapsulated in epoxy?
Epoxy is not hermetic over telecom lifetimes; moisture and oxygen still reach the laser facet and cause degradation. True hermetic sealing requires metal/glass systems.
Do CPO modules need vacuum?
Not always full vacuum — many use hermetic packages with inert gas fill. But the sealing technology, leak testing and cleanliness are the same as vacuum hardware.
Can Alpha Technology make hermetic fiber feedthroughs?
We build metal-sealed feedthroughs for vacuum service and can engineer fiber/electrical feedthroughs for hermetic packaging applications with documented leak rates.
Working on CPO or photonics packaging hardware? Contact Alpha Technology with your hermeticity target and temperature requirements.