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Highly Integrated (highly + integrate)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Self-Organization of a Highly Integrated Silicon Nanowire Network on a Si(110),16,×,2 Surface by Controlling Domain Growth

ADVANCED FUNCTIONAL MATERIALS, Issue 21 2009
Ie-Hong Hong
Abstract Here, bottom-up nanofabrication for the two-dimensional self-organization of a highly integrated, well-defined silicon nanowire (SiNW) mesh on a naturally-patterned Si(110),16,×,2 surface by controlling the lateral growths of two non-orthogonal 16,×,2 domains is reported. This self-ordered nanomesh consists of two crossed arrays of parallel-aligned SiNWs with nearly identical widths of 1.8,2.5,nm and pitches of 5.0,5.9,nm, and is formed over a mesoscopic area of 300,×,270,nm2 so as to show a high integration density in excess of 104,µm,2. These crossed SiNWs exhibit semiconducting character with an equal band gap of ,0.95,eV as well as unique quantum confinement effect. Such an ultrahigh-density SiNW network can serve as a versatile nanotemplate for nanofabrication and nanointegration of the highly-integrated metal-silicide or molecular crossbar nanomesh on Si(110) surface for a broad range of device applications. Also, the multi-layer, vertically-stacked SiNW networks can be self-assembled through hierarchical growth, which opens the possibility for creating three-dimensionally interconnected crossbar circuits. The ability to self-organize an ultrahigh-density, functional SiNW network on a Si(110) surface represents a simple step toward the fabrication of highly-integrated crossbar nanocircuits in a very straightforward, fast, cost-effective, and high throughput process. [source]

Syntheses and characterizations of thermally degradable epoxy resins.

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 11 2002

Abstract In flip-chip technology, the development of reworkable underfill materials has been one of the keys to the recovery of highly integrated and expensive board assembly designs through the replacement of defective chips. This article reports the syntheses, formulations, and characterizations of two new diepoxides, one containing secondary ester linkages and the other containing tertiary ester linkages, that are thermally degradable below 300 °C. The secondary and tertiary ester diepoxides were synthesized in three and two steps, respectively. Both compounds were characterized with NMR and Fourier transform infrared spectroscopy and formulated into underfill materials with an anhydride as the hardener and an imidazole as the catalyst. A dual-epoxy system was also formulated containing the tertiary ester diepoxide and a conventional aliphatic diepoxide, 3,4-epoxy cyclohexyl methyl-3,4-epoxycyclohexyl carboxylate (ERL-4221E), with the same hardener and catalyst. The curing kinetics of the formulas were studied with differential scanning calorimetry (DSC). Thermal properties of cured samples were characterized with DSC, thermogravimetric analysis, and thermomechanical analysis. The dual-epoxy system showed a viscosity of 18.7 and 0.87 P at 25 and 100 °C, respectively. The cured secondary, tertiary, and dual-epoxy formulas showed decomposition temperatures around 265, 190, and 220 °C, glass-transition temperatures around 120,140, 110,157, and 140,157 °C, and coefficients of thermal expansion of 70, 72, and 64 ppm/°C below their glass-transition temperatures, respectively. The shear strength of the cured dual-epoxy system decreased quickly with aging at 230 °C. The reworkability test showed that the removal of a chip underfilled with this material from the board was quite easy, and the residue on the board could be thoroughly removed with a mechanical brush without obvious damage to the solder mask. In summary, the synthesized tertiary epoxide can be used as a reworkable underfill for flip-chip applications. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1796,1807, 2002 [source]

LTCC broadband deep embedded interconnects (DEI) with application for embedded bandpass filter

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2003
J. J. Yu
Abstract Careful design of via transitions intended for use in practical microwave applications is needed to realize the advantages of low-temperature co-fired ceramic (LTCC), such as highly integrated buried passive circuits. Grounded coplanar waveguide (GCPW) to asymmetrical stripline vertical interconnects is optimized for thick LTCC substrate. The focus is to develop a vertical transition through thick substrate supporting deep embedded interconnects (DEI). The measured results demonstrate vertical transitions with good performance up to 20 GHz. Embedded LTCC bandpass filter with such vertical transition has been demonstrated with an insertion loss of 2.2 dB and return loss better than ,20 dB at 16.2 GHz. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 179,181, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11007 [source]

Acculturation, social support and academic achievement of Mexican and Mexican American high school students: An exploratory study

PSYCHOLOGY IN THE SCHOOLS, Issue 3 2002
Eric J. López
Concerns about the high dropout rate among Mexican American high school students has led researchers and educators to determine which variables affect academic success. The study investigated two factors associated with academic achievement: acculturation and social support. The sample consisted of 60 ninth-grade students of Mexican decent in a southwestern school district. Results indicated that students identified as highly integrated and strongly Anglo-oriented bicultural tended to have higher academic achievement. In addition, the sample as a whole perceived social support from all four sources. Although no generational effects were identified, females tended to have higher GPAs, and perceive more social support, while the males, interestingly, were slightly more acculturated. © 2002 Wiley Periodicals, Inc. [source]