Laser welding of glass / silicon

Joining highly dissimilar materials – glass and silicon – while ensuring high mechanical strength, perfect hermeticity and optical transparency. The challenge is to achieve a reliable bond without degrading either the optical properties of the glass or the electronic functions of the silicon.

Development of a transmission welding process using ultrashort pulse lasers, combined with numerical simulation tools to control the phenomena at the interface. This approach enables direct bonding without additives or global heat input.

Controlling complex geometries while greatly limiting heat-affected zones. The process must enable localised welding at the interface with the formation of stable volumetric weld seams, despite the differences in thermal and mechanical behaviour between the materials.

The process produces transparent weld seams with very high mechanical strength and perfect hermeticity. It ensures competitive cycle times without post-processing, while enabling the integration of electronic and optical functions within a single assembly. Resistance to thermal cycling has also been validated.