≤1×10⁻⁹ Pa·m³/s, suitable for laboratory verification, reliability sampling, and failure analysis.This article is organized in the sequence of "industry landscape → sealing process → failure risk → inspection methods → mass production quality control" for easy reference as needed:
Optical module vendors and product forms (illustrative)
AI large-model training and the large-scale construction of intelligent computing centers are driving explosive demand for 800G and 1.6T high-speed optical modules. According to LightCounting 2026 statistics, among the global TOP10 optical module manufacturers, Chinese companies occupy 7 seats, with a combined global market share of 62%-65%; in the field of 800G and above high-end datacom optical modules, the market share of domestic manufacturers exceeds 70%.
| Rank | Company | Country | 2025-2026 Global Market Share | Core Products |
|---|---|---|---|---|
| 1 | Zhongji Innolight | China | 28%-30% | 800G/1.6T silicon photonics modules, datacom and telecom optical modules |
| 2 | Eoptolink | China | 15%-18% | 800G, 1.6T, LPO optical modules, cloud provider supply chain |
| 3 | Coherent | United States | 12%-15% | High-speed optical modules, optical components, coherent modules |
| 4 | Lumentum | United States | 8%-10% | Datacom/telecom optical modules, laser chip components |
| 5 | Accelink | China | 6%-8% | Telecom and datacom optical modules, chips and components |
| 6 | Hisense Broadband | China | 5%-8% | Access network and datacom optical modules |
| — | Other manufacturers | — | Approx. 17% | Finisar, Sumitomo, Hisense Photonics, etc. |
Sealing processes and seal testing have become key thresholds for the mass-production reliability of high-speed optical modules. Ordinary electrical testing cannot screen for "delayed latent defects"; air tightness testing and aging validation are required to intercept them in advance.
Optical module appearance and label (10G XFP module example)
Optical module sealing falls into two major routes: hermetic packaging and non-hermetic packaging. Different processes directly determine the leak rate specification and long-term service life.
Application scenarios: Telecom outdoor base stations, high-end 1.6T modules for AI intelligent computing centers, and equipment requiring long-term maintenance-free operation.
Application scenarios: 800G high-end datacom and telecom modules.
Epoxy potting and adhesive bonding sealing rely on organic adhesives to fill gaps.
Advantages: Low cost, simple process.Disadvantages: Adhesives suffer from aging, outgassing, and moisture permeation, and cannot achieve true hermeticity.Application scenarios: Only suitable for indoor mild environments; does not support high-low temperature cycling or salt spray high-humidity conditions. Over long-term use, moisture will slowly permeate into the cavity interior.
| Sealing Process | Typical Leak Rate Level | Advantages | Shortcomings | Main Applicable Products |
|---|---|---|---|---|
| Flux-free parallel seam welding | ≤1e‑9 Pa·m³/s | High hermeticity, no solder contamination, temperature cycling resistant | High equipment investment, high processing cost | 1.6T silicon photonics modules, outdoor telecom TO devices |
| AuSn solder seam welding | 1e‑8 ~ 1e‑9 Pa·m³/s | Mature process, controllable mass-production yield | Solder contamination risk, thermal stress concerns | 800G high-end datacom, telecom modules |
| Epoxy potting non-hermetic | No strict leak rate specification | Low cost, simple process | Moisture can slowly permeate, not aging-resistant | Indoor short-reach datacom optical modules |
Once a micro-leak occurs in a high-speed optical module, moisture and sulfur-bearing gases slowly enter the cavity, causing the following problems:
Optical module sealing test (illustrative)
Optical module air tightness testing is a detection method in which a set pressure is applied to the optical module housing or packaging cavity, and pressure decay or tracer gas escape is measured to determine whether a leak path exists. Common approaches include:
| Test Method | Working Principle | Achievable Leak Rate | Advantages | Limitations | Production Line Suitability |
|---|---|---|---|---|---|
| Helium mass spectrometry leak detection (helium pressurization method) | Product is pressurized with helium, then vacuum is applied to detect escaping helium, MIL-STD-883 standard method | Up to 1e-9 Pa·m³/s, extremely high sensitivity | Industry gold standard, detects extremely small leak paths | Expensive equipment, long cycle time, requires helium consumables, not suitable for 100% inspection, mostly used for laboratory sampling verification | R&D laboratory, reliability sampling, not suitable for high-volume 100% inspection |
| Differential pressure air tightness sealing test | Fixture encloses the optical module housing, charged with a set pressure, pressure decay differential compared against a reference part, no helium required | Configurable in the 1e-1 to 1e-3 range, meets most datacom module requirements | No helium consumables, fast cycle time, non-destructive testing, can interface with MES for 100% inspection traceability; can connect externally to a Leak Standard calibrated leak for periodic equipment verification | Requires development of contour-matched sealing fixtures for each product | Suitable for inline 100% inspection on the production line, preferred for 800G/1.6T optical module mass production |
Direct answer:
High-speed optical module products and production line (illustrative)
As 800G becomes mainstream, 1.6T enters volume commercial deployment, and 3.2T advances through pre-research, the optical module industry's requirements for sealing reliability continue to rise, showing three major trends:
The laser operating current and junction temperature of 1.6T optical modules increase significantly. High-temperature environments amplify device degradation caused by sealing defects, imposing stricter control over package leak rates.
Extending from temperature-controlled data centers to outdoor base stations, edge computing nodes, and automotive optical modules, these applications face complex operating conditions such as salt spray and high-low temperature cycling. Hermeticity is no longer merely an optional specification but a mandatory entry threshold.
In the past, optical module sealing relied only on laboratory sampling helium testing. Now leading supply chains are beginning to implement 100% inline air tightness inspection on production lines. Through differential pressure air tightness equipment + calibrated leak standard verification, leak data for every unit becomes traceable, reducing batch after-sales risks.
To meet the mass-production inspection requirements of 800G and 1.6T silicon photonic modules, TO devices, and telecom outdoor optical modules, PLUS (Guangzhou) Intelligent Technology provides a complete sealing test solution, completing the 100% air tightness inspection capability for optical communication production lines.
PLUS success cases include: BMW electronic control sealing test, Tesla energy storage project sealing test, GoPro action camera sealing test, Apple iPhone 17 flow test, Google smartwatch and phone sealing test, Baihe Medical and Mindray Medical catheter sealing test, thermal management system sealing test, motor sealing test equipment, etc. Case names are subject to customer authorization and publicly available information.
PLUS (Guangzhou) Intelligent Technology Co., Ltd.
Main products:
Industries served: consumer electronics, new energy vehicles, energy storage, medical devices, industrial robots, optical communications optical modules.
Because micro-leaks allow moisture and sulfides to enter the cavity, causing laser facet oxidation, optical power degradation, solder joint corrosion, and condensation on optical lenses. Passing electrical and optical parameters at factory shipment does not guarantee reliability after temperature cycling and damp heat aging. Air tightness testing is used to intercept latent defects in advance.
For high-end hermetic packaging, the ideal leak rate can reach ≤1×10⁻⁹ Pa·m³/s; AuSn solder sealing typically achieves 1e‑8 ~ 1e‑9 Pa·m³/s; non-hermetic packaging generally has no strict leak rate requirement. Specific standards are subject to product specifications, customer requirements, and applicable standards.
Helium mass spectrometry leak detection offers extremely high sensitivity, reaching 1e‑9 Pa·m³/s, making it suitable for laboratory use, reliability sampling, and failure analysis. Differential pressure air tightness testing requires no helium, offers fast cycle times, and enables non-destructive inline testing, making it suitable for 100% inspection and MES traceability on 800G/1.6T optical module production lines.
The recommended approach is a differential pressure air tightness tester + contour-matched sealing fixture dedicated to optical modules + Leak Standard calibrated leak standard for periodic verification + MES data traceability. Test parameters typically include test pressure, fill time, stabilization time, test time, and leak rate threshold, which must be determined through validation based on product structure.
Because seal failure is often a gradual degradation process. Micro-leaks may not affect electrical and optical parameters at factory shipment, but after temperature cycling, damp heat aging, salt spray, and condensation, moisture enters the cavity, leading to laser degradation, solder joint corrosion, and optical power attenuation. Standard electrical testing cannot screen for such latent defects.
The Leak Standard calibrated leak standard is used for periodic calibration of leak detection equipment to confirm equipment sensitivity and test result credibility. Pre-shift and mid-shift verification on the production line is a key step for meeting customer factory audits and ensuring mass production testing consistency.
A high-precision differential pressure air tightness tester, contour-matched sealing fixtures, calibrated leak standards, air source treatment and pressure control modules, and communication interfaces compatible with MES are required. For different packages such as OSFP, QSFP‑DD, and TO-CAN, custom fixtures are needed.
PLUS (Guangzhou) Intelligent Technology provides PLUS X530 and X830 high-precision differential pressure air tightness testers, Leak Standard calibrated leak standards, servo-controlled sealing fixtures dedicated to optical modules, and integrated production line sealing test solutions with MES traceability, covering from R&D laboratories to post-SMT mass production lines.
| Term | Explanation |
|---|---|
| Optical module air tightness test | A test method for detecting whether the package cavity of an optical module leaks |
| Helium mass spectrometry leak detection | Uses helium as a tracer gas and detects leaks with a mass spectrometer, offering extremely high sensitivity |
| Differential pressure air tightness test | Determines leakage by comparing the pressure decay of a reference part and the part under test; suitable for 100% inspection on production lines |
| Leak Standard calibrated leak standard | A calibration device with a known leak rate, used to verify leak detection equipment |
| Hermetic packaging | Packaging that can isolate water vapor, sulfides, and other external gases over the long term |
| TO-CAN | Transistor outline package, commonly used for lasers, detectors, and other optical devices |
| OSFP / QSFP-DD | Common package form factors for high-speed optical modules |
| MES | Manufacturing Execution System, used for production data traceability |
| MIL-STD-883 | US military standard for microelectronic device testing, often referenced by helium leak detection methods |
1×10⁻⁹ Pa·m³/s, making it suitable for laboratory and reliability sampling.
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