Assembly Process Optimization

“DPBO – A New Control Chart for Electronics Assembly”

Author: Daryl L. Santos, Ph.D.; This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Abstract: As Six-Sigma and better processes are demanded for higher yields, and as organizations move from measuring defects in terms of parts-per-million (ppm) toward parts-per-billion (ppb), the resolution of extant control charts is becoming insufficient to monitor process quality. This work describes the development of a new SPC chart that is used to monitor processes in terms of defects-per-billion-opportunities (dpbo). A logical extension of the defects-per-million-opportunities (dpmo) control chart, calculations used to derive the dpbo control limits will be presented and examples of in-control and out-of-control processes will be offered. (SMTA Pan Pac Symposium, February 2010)

Component Fabrication

“High Performance Airbrushed Organic Thin Film Transistors”
Authors: C.K. Chan, L.J. Richter, B.Dinardo, C.Jaye, B.R. Conrad, H.W. Ro, D. S. Germack, D.A. Fischer, D.M. DeLongchamp and D. J. Gundlach; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
Abstract: High-performance airbrushed organic thin-film transistors were demonstrated and characterized using electrical and structural methods. For example, high molecular weight poly-3-hexylthiophene (P3HT) transistors exhibited an average saturation regime mobility >0.02 cm2V-1s-1, which is comparable to the best mobilities observed for transistors of this material prepared using other methods. Complex droplet and film formation dynamics were inferred, and the resulting film structure was observed using optical microscopy, atomic force microscopy, near-edge x-ray absorption fine structure spectroscopy, and grazing incidence x-ray diffraction. (Applied Physics Letters, March 30, 2010)

Conductive Polymers

“Directly Patternable, Highly Conducting Polymers for Broad Applications in Organic Electronics”
Authors: Joung Eun Yoo, Kwang Seok Lee, A. Garcia, J. Tarver, E. Gomez, K. Baldwin, Y. Sun, H. Meng, T. Nguyen, and Yueh-Lin Loo; lloo@
princeton.edu.
Abstract: Post-deposition solvent annealing of water-dispersible conducting polymers induces dramatic structural rearrangement and improves electrical conductivities by more than two orders of magnitude. We attain electrical conductivities in excess of 50 S/cm when polyaniline films are exposed to dichloroacetic acid. Subjecting commercially available poly(ethylene dioxythiophene) to the same treatment yields a conductivity as high as 250 S/cm. This process has enabled the wide incorporation of conducting polymers in organic electronics; conducting polymers not typically processable can now be deposited from solution and their conductivities subsequently enhanced to practical levels via a simple and straightforward solvent annealing process. The treated conducting polymers are thus promising alternatives for metals as source and drain electrodes in organic thin-film transistors, as well as for transparent metal oxide conductors as anodes in organic solar cells and LEDs. (Proceedings of the National Academy of Sciences, March 8, 2010)

Flexible Electronics

"A Conformal, Bio-Interfaced Class of Silicon Electronics for Mapping Cardiac Electrophysiology”

Authors: Jonathan Viventi, John Rogers, Brian Litt, et al; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
Abstract: In all current implantable medical devices such as pacemakers, deep brain stimulators, and epilepsy treatment devices, each electrode is independently connected to separate control systems. The ability of these devices to sample and stimulate tissues is hindered by this configuration and by the rigid, planar nature of the electronics and the electrode-tissue interfaces. Here, we report the development of a class of mechanically flexible silicon electronics for multiplexed measurement of signals in an intimate, conformal integrated mode on the dynamic, three-dimensional surfaces of soft tissues in the human body. We demonstrate this technology in sensor systems composed of 2016 silicon nanomembrane transistors configured to record electrical activity directly from the curved, wet surface of a beating porcine heart in vivo. The devices sample with simultaneous submillimeter and submillisecond resolution through 288 amplified and multiplexed channels. We use this system to map the spread of spontaneous and paced ventricular depolarization in real time, at high resolution, on the epicardial surface in a porcine animal model. This demonstration is one example of many possible uses of this technology in minimally invasive medical devices. (Science Translational Medicine, March 24, 2010)