• Title/Summary/Keyword: substrate degradation

Search Result 482, Processing Time 0.022 seconds

The Dependence of Mechanical Strain on a-Si:H TFTs and Metal Connection Fabricated on Flexible Substrate

  • Lee, M.H.;Ho, K.Y.;Chen, P.C.;Cheng, C.C;Yeh, Y.H.
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.439-442
    • /
    • 2006
  • We evaluated a-Si:H TFTs fabricated on polyimide substrate (PI) at the highest temperature of $160^{\circ}C$ with uniaxial and tensile strain to imitate flexible display. With tensile strain, the threshold voltage of a-Si:H TFTs have positive shift due to extra dangling bond formation in a-Si:H layer. However, no significant degradation of the subthreshold swing and effective mobility with tensile strain of a-Si:H TFTs indicates the similar level of band tail state. The metal wire with the width of $10\;{\mu}m$ for connection on flexible substrate can sustain with curvature radius 2.5 cm.

  • PDF

Prediction Methodology for Reliability of Semiconductor Packages

  • Kim, Jin-Young
    • Proceedings of the International Microelectronics And Packaging Society Conference
    • /
    • 2002.09a
    • /
    • pp.79-94
    • /
    • 2002
  • Root cause -Thermal expansion coefficient mismatch -Tape warpage -Initial die crack (die roughness) Guideline for failure prevention -Optimized tape/Substrate design for minimizing the warpage -Fine surface of die backside Root cause -Thermal expansion coefficient mismatch - Repetitive bending of a signal trace during TC cycle - Solder mask damage Guideline for failure prevention - Increase of trace width - Don't make signal trace passing the die edge - Proper material selection with thick substrate core Root cause -Thermal expansion coefficient mismatch -Creep deformation of solder joint(shear/normal) -Material degradation Guideline for failure Prevention -Increase of solder ball size -Proper selection of the PCB/Substrate thickness -Optimal design of the ball array -Solder mask opening type : NSMD -In some case, LGA type is better

  • PDF

Improved Fluorometric Assay Method for Ribonuclease Activity

  • Lee, Jong-Soo;Choi, Jong-Soo
    • BMB Reports
    • /
    • v.30 no.4
    • /
    • pp.258-261
    • /
    • 1997
  • A simple quantitative assay method for ribonuclease activity has been developed. This method is based on the decrease of fluorescence intensity emitted by the ethidium bromide bound to RNA due to the degradation of RNA by ribonuclease. The substrate RNA was reacted with ribonuclease A and the fluorescence intensity was measured after the addition of ethidium bromide. The intensity difference was calculated using a blank reaction mixture containing no RNase. Whole cellular RNA substrate produced a significant error and was not suitable for this assay method possibly because of local microheterogeniety caused by high molecular weight rRNA. but satisfying results were obtained with tRNA substrate. The intensity difference increased linearly by raising enzyme concentration up to $2{\times}10^{-4}$ Kunitz Units of ribonuclease A. More refined and reliable results were obtained by use of initial reaction velocities which were calculated from the plots of intensity difference vs time. A linear relationship between initial velocities and enzyme concentrations was observed up to 0.01 Kunitz Units of enzyme.

  • PDF

Control of Residual Stress in Diamond Film Fabricated by Hot Filament CVD (열 필라멘트 CVD법에 의해서 제작한 다이아몬드 막의 잔류응력제어)

  • 최시경;정대영;최한메
    • Journal of the Korean Ceramic Society
    • /
    • v.32 no.7
    • /
    • pp.793-798
    • /
    • 1995
  • The relaxation of the intrinsic stresses in the diamond films fabricated by the hot filament CVD was studied, and it was confirmed that the tensile intrinsic stresses in the films could be controlled without any degradation in the quality of the diamond films. The tensile intrinsic stresses in the films decreased from 2.97 to 1.42 GPa when the substrate thickness increased from 1 to 10mm. This result showed that the residual stress was affected by the substrate thickness as well as by the interaction between grains. Applying of +50 V between the W filament and the Si substrate during deposition, the tensile intrinsic stress in the film deposited at 0 V was decreased from 2.40 GPa to 0.71 GPa. Such large decrease in the tensile intrinsic stress was due to $\beta$-SiC which acted as a buffer layer for the stress relaxation. However, the application of the large voltage above +200V resulted in the change of quality of the diamond film, and nearly had no effect on relaxation in the tensile intrinsic stress.

  • PDF

Substrate specificity of bacterial endoribonuclease toxins

  • Han, Yoontak;Lee, Eun-Jin
    • BMB Reports
    • /
    • v.53 no.12
    • /
    • pp.611-621
    • /
    • 2020
  • Bacterial endoribonuclease toxins belong to a protein family that inhibits bacterial growth by degrading mRNA or rRNA sequences. The toxin genes are organized in pairs with its cognate antitoxins in the chromosome and thus the activities of the toxins are antagonized by antitoxin proteins or RNAs during active translation. In response to a variety of cellular stresses, the endoribonuclease toxins appear to be released from antitoxin molecules via proteolytic cleavage of antitoxin proteins or preferential degradation of antitoxin RNAs and cleave a diverse range of mRNA or rRNA sequences in a sequence-specific or codon-specific manner, resulting in various biological phenomena such as antibiotic tolerance and persister cell formation. Given that substrate specificity of each endoribonuclease toxin is determined by its structure and the composition of active site residues, we summarize the biology, structure, and substrate specificity of the updated bacterial endoribonuclease toxins.

Degradation Characteristics of A Novel Multi-Enzyme-Possessing Bacillus licheniformis TK3-Y Strain for the Treatment of High-Salinity Fish Wastes and Green Seaweeds

  • Kang, Kyeong Hwan;Kim, Joong Kyun
    • Fisheries and Aquatic Sciences
    • /
    • v.18 no.4
    • /
    • pp.349-357
    • /
    • 2015
  • To reutilize fisheries waste, we isolated a bacterial strain from a coastal area located in Busan. It was identified as Bacillus licheniformis TK3-Y. Using plate assay and 500-mL flask experiments, we found that the isolate simultaneously possessed cellulolytic, proteolytic, and lipolytic activities with salt tolerance. 10% (v/v) inoculums, were used to examine the biodegradation characteristics of the TK3-Y strain on carboxymethylcellulose, skim milk, and olive oil media. The optimum conditions for pH, temperature, agitation speed, and NaCl concentration on each 1% substrate were 6, $50^{\circ}C$, 180 rpm, and 17.5%, respectively. Under optimal conditions, the TK3-Y strain showed 1.07 U/mL cellulolytic, 1,426 U/mL proteolytic, and 6.45 U/mL lipolytic activities. Each enzyme was stable within a range of 17.5-35% NaCl. Therefore, the salt tolerance ability of strain TK3-Y was superior to other related strains. In degradation of a mixed medium containing all three substrates, both the cellulolytic and proteolytic activities were somewhat lower than those on each single substrate, while the lipolytic activity was somewhat higher. From the above results, the TK3-Y strain appears to be a good candidate for use in the efficient treatment of fisheries waste in which components are not collected separately.

Numerical Classification of Actinomycetes Isolated from Volcanic Soil

  • Kim, Seung-Bum;Lee, Soon-Dong;Kim, Seon-Young;Oh, Hyung-Myung;Kang, Sa-Ouk
    • Journal of Microbiology
    • /
    • v.34 no.2
    • /
    • pp.105-116
    • /
    • 1996
  • Of actinomycetes isolated from volcanic compost soils, 115 representative strains which showed distinctive morphologicla features were numerically classified, compared with reference strains of Streptomyces. One hundred and twenty unit characters were tested and the average probability of error was 4.27%. The cluster analysis resulted in two groups: group A included strains of actinomycetes except streptomycetes. Group A was divided into 2 major clusters (over 5 strains), 10-diaminopimelic acid. Group B was divided into 5 clusters, of which 4 clusters contained mesodiminopimelic acid and 1 cluster LL-diaminopimelic acid. The major clusters of group A showed higher abilities of substrate utilization and degradation, and higher resistance to inhibitors, whereas the minor and single member clusters of group A showed relatively higher antimicrobial activities. On the other hand, all clusters of group B showed relatively lower abilities of substrate utilization and degradation and lower resistance to inhibitors.

  • PDF

Degradation and Failure Analysis of Lead-free Silver Electrodes with Thermal Cycling (무연계 Ag 외부전극재의 열충격에 따른 열화특성과 고장해석)

  • Kim, Jung-Woo;Yoon, Dong-Chul;Lee, Hee-Soo;Jeon, Min-Seok;Song, Jun-Kwang
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.21 no.5
    • /
    • pp.434-439
    • /
    • 2008
  • Silver pastes as the outer electrodes have been prepared using Pb-free glass frits with different content of $Bi_2O_3$ and the effects of glass composition on the degradation behaviors of the Ag electrodes were investigated using the change of adhesion between Ag electrode and alumina substrate with thermal cycle stress. Low adhesion and high surface resistance were observed in Ag electrode using glass frit with a $Bi_2O_3$ content of 60 wt%, owing to the open microstructure formed at the firing temperature of $600^{\circ}C$. When the $Bi_2O_3$ was increased to 80 wt% in the glass frit, the Ag electrodes had a dense microstructure with high adhesion and a low surface resistance. Delamination of the Ag electrodes was a major failure mode under thermal cycle stress and this was attributed to residual stress due to the thermal expansion mismatch between the Ag electrode and the alumina substrate.

Overexpression and Purification of Monooxygenases Cloned from Arthrobacter chlorophenolicus A6 for Enzymatic Decomposition of 4-Chlorophenol (4-Chlorophenol 분해박테리아 Arthrobacter chlorophenolicus A6로부터의 monooxygenase의 복제 및 대량발현과 정제 그리고 기질분해활성도 분석)

  • Ryu, Song-Jung;Kang, Christina S.;Kim, Han S.
    • Journal of Soil and Groundwater Environment
    • /
    • v.19 no.3
    • /
    • pp.47-55
    • /
    • 2014
  • Arthrobacter chlorophenolicus A6 possesses several monooxygenases (CphC-I, CphC-II, and CphB) that can catalyze the transformation of 4-chlorophenol (4-CP) to hydroxylated intermediates in the initial steps of substrate metabolism. The corresponding genes of the monooxygenases were cloned, and the competent cells were transformed with these recombinant plasmids. Although CphC-II and CphB were expressed as insoluble forms, CphC-I was successfully expressed as a soluble form and isolated by purification. The specific activity of the purified CphC-I was analyzed by using 4-CP, 4-chlorocatechol (4-CC), and catechol (CAT) as substrates. The specific activities for 4-CP, 4-CC, and CAT were determined to be 0.312 U/mg, 0.462 U/mg, 0.246 U/mg, respectively. The results of this study indicated that CphC-I is able to catalyze the degradation of 4-CC and CAT in addition to 4-CP, which is a primary substrate. This research is expected to provide the fundamental information for the development of an eco-friendly biochemical degradation of aromatic hydrocarbons.

FE-SEM Image Analysis of Junction Interface of Cu Direct Bonding for Semiconductor 3D Chip Stacking

  • Byun, Jaeduk;Hyun, June Won
    • Journal of the Korean institute of surface engineering
    • /
    • v.54 no.5
    • /
    • pp.207-212
    • /
    • 2021
  • The mechanical and electrical characteristics can be improved in 3D stacked IC technology which can accomplish the ultra-high integration by stacking more semiconductor chips within the limited package area through the Cu direct bonding method minimizing the performance degradation to the bonding surface to the inorganic compound or the oxide film etc. The surface was treated in a ultrasonic washer using a diamond abrasive to remove other component substances from the prepared cast plate substrate surface. FE-SEM was used to analyze the bonding characteristics of the bonded copper substrates, and the cross section of the bonded Cu conjugates at the sintering junction temperature of 100 ℃, 150 ℃, 200 ℃, 350 ℃ and the pressure of 2303 N/cm2 and 3087 N/cm2. At 2303 N/cm2, the good bonding of copper substrate was confirmed at 350 ℃, and at the increased pressure of 3087 N/cm2, the bonding condition of Cu was confirmed at low temperature junction temperature of 200 ℃. However, the recrystallization of Cu particles was observed due to increased pressure of 3087 N/cm2 and diffusion of Cu atoms at high temperature of 350 ℃, which can lead to degradation in semiconductor manufacturing.