Laser joining of non-metallics for optoelectronic and biomedical applications

Advanced microsystems for optoelectronic and biomedical applications incorporate a variety of non-metallic materials such as glass, silicon, sapphire and polymers. Examples include switches and multiplexers for fiber-optical data transmission in telecommunications, and innovative implantable microsystems currently being developed to monitor, stimulate and deliver drugs. Laser micromachining has proven to be an effective tool to address specific manufacturing challenges for these devices. Studies have been conducted on laser cutting, laser drilling and laser ablation for precise localized material removal. Application data for a range of relevant materials also exists. In contrast, applications of laser joining are currently limited to microwelding and soldering of metals. The assembly of surface mounted devices (SMD) and the sealing of pacemakers are typical examples. This paper describes the latest achievements in laser microjoining of non-metallic materials. The focus will be on glass and silicon that have been joined using CO2, Nd:YAG and diode lasers. Results in joining similar and dissimilar materials in different joint configurations are presented, as well as requirements for sample preparation and fixturing are discussed. The potential for applications in the optoelectronic and biomedical sector is demonstrated.