• 제목/요약/키워드: X-ray microscopy

검색결과 3,210건 처리시간 0.033초

FLIP CHIP SOLDER BUMPING PROCESS BY ELECTROLESS NI

  • Lee, Chang-Youl;Cho, Won-Jong;Jung, Seung-Boo;Shur, Chang-Chae
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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    • pp.456-462
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    • 2002
  • In the present work, a low cost and fine pitch bumping process by electroless Ni/immersion Au UBM (under bump metallurgy) and stencil printing for the solder bump on the Al pad is discussed. The Chip used this experimental had an array of pad 14x14 and zincate catalyst treatment is applied as the pretreatment of Al bond pad, it was shown that the second zincating process produced a dense continuous zincating layer compared to first zincating. Ni UBM was analyzed using Scanning electron microscopy, Energy dispersive x-ray, Atomic force microscopy, and X-ray diffractometer. The electroless Ni-P had amorphous structures in as-plated condition. and crystallized at 321 C to Ni and Ni$_3$P. Solder bumps are formed on without bridge or missing bump by stencil print solder bump process.

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Electrochemical Behavior and Biocompatibility of Co-Cr Dental Alloys

  • Kang, Jung-In;Yoon, Jun-Bin;Choe, Han-Cheol
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2015년도 춘계학술대회 논문집
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    • pp.107-107
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    • 2015
  • In order to investigate electrochemical behavior and biocompatibility of Co-Cr dental alloy by electrochemical corrosion test and MTT assay, the xCo-25Cr-yW-zNi alloys were used in this study. Samples of Co-Cr-W-Ni alloys were manufactured using arc melting furnace. The microstructure of the alloys was examined by optical microscopy (OM), Field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), MTT assay, and corrosion test. Corrosion resistance increased slightly as cobalt (Co) content increased. And bioactivity was concerned with nickel (Ni) and tungsten (W). Biocompatibility of Co-Cr alloy depended on Ni and W contents.

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Regulation of depth and composition of airway surface liquid

  • J. H. Widdicombe;S. J. Bastacky;D. X.Y. Wu;Lee, C. Y.
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1996년도 춘계학술대회
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    • pp.119-130
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    • 1996
  • We review the factors which regulate the depth and composition of the human airway surface liquid (ASL). These include secretion from airway submucosal glands, ion and fluid transport across the surface epithelium, goblet cell discharge, surface tension and transepithelial gradients in osmotic and hydrostatic pressure. We describe recent experiments in which we have used low temperature scanning electron microscopy of rapidly frozen specimens to detect changes in depth of ASL in response to submucosal gland stimulation. We also present preliminary data in which X-ray microanalysis of frozen specimens has been used to determine the elemental composition of ASL.

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$(1-x)NdAlO_3-xCaTiO_3$ 시스템의 미세구조 관찰 (Microstructure Observations in $(1-x)NdAlO_3-xCaTiO_3$ System)

  • 이확주;류현;박현민;조양구;김재천;남산
    • Applied Microscopy
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    • 제32권1호
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    • pp.9-15
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    • 2002
  • NACT 복합 페브로스카이트 화합물에 대한 미세조직 관찰을 X-ray diffractometer, neutron diffraction 그리고 TEM으로 관찰하였다. $0.3{\leq}x{\leq}0.9$일 때 NACT는 양이온의 1 : 1 chemical ordering 뿐만 아니라 산소팔면체의 antiphase와 inphase tilting을 보여준다. 따라서 APB와 ferroelastic domain 경계가 미세구조에 나타나 있다. X값이 0.3보다 작아지면, chemical ordering은 나타나지 않고 단지 산소팔면체의 antiphase tilting 만이 나타난다. 미세구조에는 tangled dislocation과 2차상이 또한 발견되었다.

Design of a Cylindrical Flexure Jointed Stewart Platform for Aligning the Condenser in an X-ray Microscope

  • Kang Sung-Hoon;Kang Dong-Woo;Gweon Dae-Gab;Yoon Gwon-Ha;Min Jin-Young
    • International Journal of Precision Engineering and Manufacturing
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    • 제7권3호
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    • pp.60-65
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    • 2006
  • This paper proposes a new type of six degree-of-freedom fine positioner that can be used to align the condenser in X-ray microscopy precisely. The new concept was based on the requirements for an X-ray microscope. A proposed modeling method was used to obtain an optimal design, which was verified with a finite element analysis. The fine positioner was then constructed and an experiment was used to validate its performance.

Insight Into the Crystallinity of Chinese Ancient Silk by Synchrotron Radiation-Based and Conventional X-ray Diffraction Methods

  • Gong, Decai;Zhang, Xiaoning;Gong, Yuxuan
    • 보존과학회지
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    • 제36권1호
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    • pp.1-14
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    • 2020
  • This study investigates the crystallinity distribution of ancient silk. Owing to the inherent multi-hierarchical structure of silk protein and the complicated structural changes that occur due to various burial environments, it is challenging but worthwhile to study ancient silk ageing behavior, which is based on the fact that ageing begins with a single fiber and then spreads to a whole fabric. Crystallinity was one of the most effective indicators found to reveal the ageing status of silk. Therefore, a synchrotron radiation-based X-ray diffraction(SR-XRD) method was employed to study the crystallinity distribution of single fibers of ancient silk unearthed from seven archaeological sites in China from historical periods including the warring states, Han dynasty, Song dynasty, and Ming dynasty. In comparison, the conventional X-ray diffraction method, which uses large amounts of samples, was also performed to determine the integral crystallinity of ancient silk. Thermal stability experiments by thermogravimetry(TG) as well as morphology observations by scanning electron microscopy(SEM) and optical microscopy(OM) all confirmed the deterioration of ancient silk. Moreover, the ageing mechanism of ancient silk was proposed with the assistance of an artificial ageing study. The results confirmed the effectiveness of SR-XRD as an ageing indicator, revealing the crystallinity distribution. This research could provide motivation to determine the deterioration status of ancient silk, and would also aid in explaining the fragility of ancient silk due to ageing.