Joining Challenges in the Assembly and Packaging of Implantable Biomedical Devices

R. Witte¹, H.J. Herfurth1, S. Heinemann¹, G. Newaz², A. Mian², D. Georgiev², G. Auner²

¹Fraunhofer Center for Laser Technology CLT, Plymouth, MI, USA

 ²Wayne State University, College of Engineering, Detroit, Michigan, USA

Abstract:

Research and development efforts in BioMEMS and MOEMS are currently driven by the vast potential of implantable biomedical devices for the treatment of disease. A variety of implants already exist including such well-known devices as pacemakers and defibrillators. Other examples are neural stimulators for the treatment of seizures and cochlear implants for hearing impaired patients. Novel implantable microsystems currently under development incorporate increased functionality such as localized sensing of temperature and pressure, electrical stimulation of neural tissue and the delivery of drugs. These devices are designed for long-term implantation and therefore are remotely powered and controlled. The development of new, biocompatible materials and manufacturing processes that ensure long-lasting functionality and reliability are critical challenges. Materials selection is based mainly on functionality of the device. Important factors in the assembly and packaging of such systems are the minute size of the features, the heat sensitivity of integrated electronics and media, and the type of materials and material combinations to be hermetically sealed. Laser micromachining has emerged as a compelling solution to address these manufacturing challenges. Fraunhofer has been successfully developing advanced laser joining and packaging technology for many years. This paper will describe the latest achievements in microjoining of dissimilar materials. The focus is on glass, metal and polymers 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. The potential for applications in the biomedical sector will be demonstrated.