caa a22 4500 463222393 CHVBK 20180405153216.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1007/s10853-007-1703-x doi (NATIONALLICENCE)springer-10.1007/s10853-007-1703-x Mechanical characterization of glass/polyimide microjoints fabricated using cw fiber and diode lasers [Elektronische Daten] [Ahsan Mian, Golam Newaz, Tonfiz Mahmood, Greg Auner] This paper discusses the laser-irradiated microjoints between glass and polyimide for applications in neural implants. To facilitate bonding between them, a thin titanium film with a thickness of approximately 0.2μm was deposited on glass wafers using the physical vapor deposition (PVD) process. Two sets of samples were fabricated where the bonds were created using diode and fiber lasers. The samples were subjected to tension using a microtester for bond strength measurements. The failure strengths of the bonds generated using fiber laser are quite consistent, while a wide variation of failure strengths are observed for the bonds generated with diode laser. Few untested samples were sectioned and the microstructures near the bond areas were studied using an optical microscope. The images revealed the presence of a sharp crack in the glass substrate near the bond generated with the diode laser. However, no such crack was observed in the samples made using fiber laser. To investigate the reasons behind such discrepancy in bond quality further, uncoupled three-dimensional finite element analyses (FEA) were conducted only for the samples created using diode laser. First, the transient heat diffusion-based FEA was conducted by using the laser power intensity distribution as a time dependent heat source. This model calculates the temperature distribution within the substrates as a function of time. Next, the structural model predicts the amount of residual stresses developed in the joint system as it is cooled down to room temperature. The out-of-plane normal component of residual stresses was within the failure strength range of glass that may have caused fracture initiation in the substrate. Springer Science+Business Media, LLC, 2007 Mian Ahsan Department of Mechanical and Industrial Engineering, Montana State University, 220 Roberts Hall, Bozeman, MT, USA aut Newaz Golam Department of Mechanical Engineering, Wayne State University, Detroit, MI, USA aut Mahmood Tonfiz Department of Mechanical Engineering, Wayne State University, Detroit, MI, USA aut Auner Greg Department of Electrical and Computer Engineering, Wayne State University, Detroit, MI, USA aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/19(2007-10-01), 8150-8157 0022-2461 42:19<8150 2007 42 10853 https://doi.org/10.1007/s10853-007-1703-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-007-1703-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mian Ahsan Department of Mechanical and Industrial Engineering, Montana State University, 220 Roberts Hall, Bozeman, MT, USA aut NATIONALLICENCE 700 1- Newaz Golam Department of Mechanical Engineering, Wayne State University, Detroit, MI, USA aut NATIONALLICENCE 700 1- Mahmood Tonfiz Department of Mechanical Engineering, Wayne State University, Detroit, MI, USA aut NATIONALLICENCE 700 1- Auner Greg Department of Electrical and Computer Engineering, Wayne State University, Detroit, MI, USA aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/19(2007-10-01), 8150-8157 0022-2461 42:19<8150 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer