Next-generation microvia and global wiring technologies for SOP

© 2004 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.DOI: 10.1109/TADVP.2004.831890As microsystems continue to move toward higher speed and microminiaturization, the demand for interconnection density both on the IC and the package levels increases tremendously. The 2002 ITRS roadmap update identifies the need for sub-100-µm area array pitch and data rates of 10 Gb/s in the package or board by the year 2010, requiring much finer lines and vias than the current microvias of 50 µm diameter and lines and spaces of 25 µm. After a brief description of the future need for high-density substrates, the historical evolution of microvia technologies worldwide is summarized. With the move toward highly integrated and higher performance system-on-a-package (SOP) technology, the demand for microvia wiring density in the package is increasing dramatically requiring new innovations in fine line, ultralow-loss, and ultrathin-film dielectrics. The low-cost needs of this technology are driving research in high throughput and large area processes in dielectric and conductor deposition. The third section of this paper describes in detail some of the key emerging global microvia research and development in the fabrication of microminiaturized, multifunction SOP packages including rapid curing of low-loss dielectric thin films on organic substrates, environmentally friendly high-speed electroless copper plating, ultrafine lines, and spaces down to 5 µm and low-cost stacked via structures without chemical-mechanical polishing. This paper concludes with a perspective on future directions in dielectrics and conductor materials and processes leading to ultrahigh-density and low-cost microvia technologies for build-up SOP implementation

45 Degree Polymer Micromirror Integration for Board-Level Three-Dimensional Optical Interconnects

© 2009 Optical Society of AmericaThe definitive version of this paper is available at: http://dx.doi.org/10.1364/OE.17.010514DOI: 10.1364/OE.17.010514We introduce here a simple method of integrating 45° total internal reflection micro-mirrors with polymer optical waveguides by an improved tilted beam photolithography on printed circuit boards to provide surface normal light coupling between waveguides and optoelectronic devices for optical interconnects. De-ionized water is used to couple ultraviolet beam through the waveguide core polymer layer at 45° angle during the photo exposure process. This technique is compatible with PCB manufacturing facility and suitable to large panel board-level manufacturing. The mirror slope is controlled accurately (within ±1°) with high repeatability. The insertion loss of an uncoated micro-mirror is measured to be 1.6 dB

Precision measurements for propagation properties of high-definition polymer waveguides by imaging of scattered light

©2008 SPIE--The International Society for Optical Engineering. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. The electronic version of this article is the complete one and can be found online at: http://dx.doi.org/10.1117/1.2842390DOI: 10.1117/1.2842390We present a reliable, nondestructive, and real-time technique for characterization of propagation properties of planar optical waveguides based on accurately imaging the scattered light from the optical waveguide using a sensitive charge-coupled device (CCD) camera with built-in integration functionality. This technique can be used for real-time investigation of the propagation properties (loss, mode profile, bending properties, etc.) as well as the fabrication quality of planar optical waveguides. With this technique, we evaluate high-definition polymer optical waveguides on printed circuit board (PCB) substrates with a very low loss of 0.065dB/cm at a wavelength of 850nm, and measurement accuracy is less than 0.01dB/cm. We expect this technique with the given CCD camera to be suitable for reliably measuring loss coefficients well below 0.1dB/cm

Analysis of the spatial evolution of coastal defense patterns in the Ming Dynasty based on long-time-series Wokou invasions (Zhejiang)

Abstract As a famous coastal defense heritage in the world’s military history, the maritime defense heritage of China’s Ming Dynasty represents the highest achievement of China’s ancient coastal military defense. There is a relative lack of holistic research on this defense system from its establishment to stabilization. Additionally, there is a lack of comparative research on the combination of Wokou invasions and defense patterns from a spatio-temporal perspective. The study aims to offer insights into the temporal and spatial evolution of ancient military defense heritage and investigate the significance of Ming Dynasty coastal defense. This study focuses on Zhejiang, a key coastal defense during the Ming Dynasty. Using GIS tools, it analyzes the spatio-temporal evolution characteristics of Wokou invasions and defense mode in the process of Zhejiang coastal defense from its establishment to its perfection by using GIS analytical tools, and explores the driving factors of the dynamic adjustment of this coastal defense system. The results show that: (1) Hongwu 1 to 31 (1368–1398) witnessed the construction of a 12-area defense system, encompassing Wei and Suo citadels. This followed a multi-point defense strategy, with Wei citadels controlling the coastline and Suo citadels supporting them; (2) Hongwu to Wanli (1368–1588) saw the evolution of five defense modes, evolving from decentralized to centralized and then to a coexistence of both. This culminated in the establishment of 4–6 Defense Mode (4 Canjiang and 6 Bazong); (3) the evolution of the defense paradigm is largely driven by Wokou incursions and is an adaptation from small-scale, short-duration infestations to large-scale, long-duration infestations. The findings show that the Ming Dynasty’s coastal defense system in China was flexible and adaptive, evolving to meet changing defense needs

Proximity Lithography in Sub-10 Micron Circuitry for Packaging Substrate

© 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Rapid changes in the semiconductor industry will continue toward higher functionality that leads to higher input/outputs (I/O) counts, pushing packaging towards higher density architectures. In the next two to three years, the I/O pitch will fall within 100 μm for area array die and 30 μm for periphery die. That raises an important question to the packaging industry: How will the rapid shrinkage of the I/O pitch affect the package substrate for chip attaching? The answer is sub-10 micron copper line technology. Theoretical and experimental studies on the limitations of using mercury i-line ultraviolet photolithography have been carried at the Packaging Research Center at Georgia Tech. Furthermore, ultra fine copper line routing substrates are demonstrated for flip chip attaching by using semi-additive metallization process

"Zero-Undercut" Semi-Additive Copper Patterning -A Breakthrough for Ultrafine-line RDL Lithographic Structures and Precision RF Thinfilm Passives

Abstract This paper presents the first demonstration of a "zeroundercut" precision formation of ultrafine-line copper conductor patterns for redistribution layers (RDL) and thin film RF passives. This is accomplished by using a highlyanisotropic and uniform copper plasma-etching process to remove the seed layer with no lateral etching of the copper patterns, unlike what is seen with traditional seed-layer removal by wet-etching. Application of this technical breakthrough for large-area panel processes allows demonstration of precision copper patterns demonstrated, for the first time, on organic laminates with no measurable lateral undercut. Two different plasma chemistries, one pure physical sputter-etching, and the other based upon chemical-physical processes with a hydrogen plasma, were investigated and compared

Detecting Early Stage Pressure Ulcer on Dark Skin Using Multispectral Imager

©Copyright 2010 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.Presented at the SPIE International Symposium on Biomedical Vibrational Spectroscopy, 2010, San Francisco, CA.http://dx.doi.org/10.1117/12.85108

Single sensor that outputs narrowband multispectral images

© 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3277669]We report the work of developing a hand-held (or miniaturized), low-cost, stand-alone, real-time-operation, narrow bandwidth multispectral imaging device for the detection of early stage pressure ulcers