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91.
Analyses of the practical adhesion strengths of the metal/polymer interfaces in electronic packaging
There is a plethora of techniques to measure the adhesion strength of metal/polymer interfaces. However, the practical adhesion
strength, which is the work done in separating the film from the substrate (or one film from another), is very sensitive to
the test methods and the mechanical effects, such as the residual stress, thickness and mechanical properties of the layers,
strain rate, and phase angle. Deriving intrinsic-adhesion properties of the interfaces, which are independent of such parameters,
from the practical adhesion-strength measurements is a formidable task. In the present work, data from the three commonly
used adhesion tests; pull-out, 90°-peel, and T-peel tests are compared with the intrinsic-adhesion properties of the interface,
such as the interface-fracture toughness or the interface-fracture energy, and their implications are discussed. Material
systems analyzed were Cu-based lead frame/epoxy-molding compound (EMC) and Cu/Cr/polyimide. 相似文献
92.
K-S. Park S-H. Park Y-K. Sun K-S. Nahm Y-S. Lee M. Yoshio 《Journal of Applied Electrochemistry》2002,32(11):1229-1233
The structural and electrochemical properties of LiNiO2 powders were investigated as a function of the oxygen flow rate employed in the preparation of lithium nickel oxide. It was found that oxygen played an important role in the synthesis of highly crystallized LiNiO2(R3¯m). In the crystallization process of LiNiO2, a deficiency of oxygen in the calcination reactor induced the formation of impurities and cubic rock-salt structure (Fm3m) in LiNiO2 powders. For LiNiO2 prepared at higher oxygen flow rates, the electrode delivered high discharge capacities with relatively good retention rates. But very low electrode capacity was obtained from LiNiO2 prepared at lower oxygen flow rates. 相似文献
93.
Kyeong Joong Kim Jong-Yeul Suh Moon Gi Kang Kyu Tae Park 《Electronics letters》1998,34(13):1302-1303
The boundary is approximated by a polygon which can be encoded with the smallest number of bits for maximum distortion. The temporal redundancy between two successive frames is efficiently removed with the proposed scheme, resulting in a lower bit rate than the conventional algorithms 相似文献
94.
DC and microwave measurements on AlSb/InAs HEMTs with a gate length of 0.21 μm are reported. The reverse gate characteristics exhibit relatively low gate leakage current and gate-drain breakdown voltages as high as 5 V. Equivalent circuit modelling yields an fT of 110 GHz after removal of the gate bonding pad capacitance. The bias dependence of fmax is examined indicating a significant reduction in the unilateral gain due to impact ionisation 相似文献
95.
White Desiree A.; Craft Suzanne; Hale Sandra; Park T. S. 《Canadian Metallurgical Quarterly》1994,8(2):180
A. D. Baddeley, N. Thomson, and M. Buchanan (1975) suggested that articulatory rehearsal rate determines the amount of verbal material that can be maintained in working memory. In the current study, 12 children with spastic diplegic cerebral palsy (SDCP) and 38 normal children were tested on measures of articulation rate and memory span for 1-, 2-, and 3-syllable words. Across all conditions, articulation rate for the SDCP group was significantly slower than for the normal group; nonetheless, memory span was equivalent for both groups. This finding implies that covert rehearsal proceeded normally for the SDCP group, in spite of decrements in speech rate. Thus, the relationship between overt and covert rehearsal rates differs for children with SDCP compared with normal children. Findings from the current study further suggest that normal speech rates are not necessary for development of normal covert rehearsal rates. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
96.
97.
A new controller for a digital audio amplifier with bit stream input is proposed. The proposed controller has excellent features such as wide error correction range and no limitation on the modulation index. The controller is implemented in the half-bridge class-D amplifier and performance is verified through experiments. 相似文献
98.
The interaction of alkali metal with surfaces has been of great interest to the community of catalysis since alkali metal can play an important role as a promoter. On alkali-doped MoS2, such a promotion effect of alkali metal has been exemplified in the direct synthesis of linear alcohols from CO and H2, where the alkali-doping switches the catalyst selectivity from methanation to alcohol synthesis. This paper reviews recent high-resolution X-ray photoelectron spectroscopy experiments that have provided direct
observation of electron transfer from alkali metals to a model single crystal MoS2 and the capture of the supra-valence electrons in the subsequent oxidation reactions. 相似文献
99.
100.
This paper deals with the pricing and investment decision problem of multi-modal transportation systems in which the congestion
is a significant factor in the assessment of system costs. This study approaches this congestion pricing problem with a number
of social welfare maximization problems, all of which have the identical structure except financial constraints. One welfare
maximization problem examined in this study yields the pricing and investment decision, which can attain the first-best social
optimality for multi-modal transportation systems. Other welfare maximization problems show he second-best optimal solutions
that can address two policy questions in transportation economics, namely, the cross-subsidy between competing modes and peak-period
congestion charges on a single highway link.
Received: February 2001/Accepted: December 2001
This work was supported in part by funds from BK21 Research Division of Seoul National University for Social Infrastructure
and Construction Technology. 相似文献