Hermetic Packaging for LiDAR — Two Wavelengths, Two Routes

I. 905nm vs. 1550nm: One Plays It Safe, the Other Reaches Far

The previous article covered silicon photonics packaging; this one turns to the "eyes" of intelligent driving — LiDAR.

LiDAR's mainstream wavelengths follow two routes: 905nm and 1550nm. The 905nm route started earlier, has a mature supply chain and relatively low cost, making it the mainstream market choice today. But it sits close to visible light, and for the sake of eye safety its emission power is strictly limited.

The 1550nm route is the opposite — it stays far from the eye-sensitive band, allows higher emission power, and enables longer detection range. The trade-offs are higher component cost, and light sources and detectors that are particularly sensitive to moisture and impurities, raising the bar for hermetic packaging accordingly.

Xuri has mature products on both routes: TO-series headers for the 905nm route, and butterfly and ceramic packages for the 1550nm route.

II. Packaging That Rides in a Car — Which Hurdles Must It Clear?

LiDAR is not installed in a machine room — it is installed on a vehicle, expected to work year-round through wind and rain. That means three hurdles for the package.

The first is temperature. The bitter cold of northern winters and the scorching heat of summer sun demand that the package never cracks or leaks under drastic thermal swings — this depends on how closely the thermal expansion of the housing and the glass are matched, and it is the core competence of glass-to-metal sealing technology.

The second is vibration. Continuous bumps and sudden-brake shocks during driving test the "muscles and bones" of the sealing interface and solder layers. The package must endure years of vibration without developing micro-cracks.

The third is lifetime. A LiDAR unit must accompany its owner safely for over a decade — an early "retirement" is unacceptable. The package must keep moisture firmly outside for the entire life of the product.

[Next Article] Next up: localization of packaging materials — the domestic story of housings, glass and pastes.

[Glossary]

1. 905nm / 1550nm: the two mainstream operating wavelengths for LiDAR; 905nm offers low cost and a mature supply chain, while 1550nm offers longer detection range and better eye safety.

2. LiDAR: a sensor that perceives 3D information about its surroundings by emitting laser light and receiving reflections — one of the core components of intelligent driving.