Microjoining of dissimilar materials for Optoelectronic and Biomedical Applications  

Reiner Witte, Hans J. Herfurth, Ingo Bauer

Fraunhofer Center for Laser Technology, Plymouth, MI

Abstract:

The growing market of bio-medical implants combined with integrated circuits is one of the high potential research fields of the last years. Advanced microsystems for biomedical and also for optoelectronic applications incorporate a variety of dissimilar 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. Investigations have been conducted on laser ablation for precise localized material removal, laser cutting, and drilling; and application data for a range of relevant materials already exists. In contrast, applications of laser joining are currently limited to microwelding and soldering of metals. The assembly of SMD’s and the sealing of pacemakers are typical examples.

This paper will describe the latest achievements in laser microjoining of similar and dissimilar materials. The focus will be on glass-to-glass, glass-to-polymer and metal-to-polymer that have been joined using CO2, Nd:YAG and diode lasers. Results in joining similar and dissimilar materials in different joint configurations will be presented, as well as requirements for sample preparation and fixturing. The potential for applications in the optoelectronic and biomedical sector will be demonstrated.