• Title/Summary/Keyword: $AL_2O_3$

Search Result 6,354, Processing Time 0.031 seconds

Ni/Au Electroless Plating for Solder Bump Formation in Flip Chip (Flip Chip의 Solder Bump 형성을 위한 Ni/Au 무전해 도금 공정 연구)

  • Jo, Min-Gyo;O, Mu-Hyeong;Lee, Won-Hae;Park, Jong-Wan
    • Korean Journal of Materials Research
    • /
    • v.6 no.7
    • /
    • pp.700-708
    • /
    • 1996
  • Electroless plating technique was utilized to flip chip bonding to improve surface mount characteristics. Each step of plating procedure was studied in terms pf pH, plating temperature and plating time. Al patterned 4 inch Si wafers were used as substrstes and zincate was used as an activation solution. Heat treatment was carried out for all the specimens in the temperature range from room temperature to $400^{\circ}C$ for $30^{\circ}C$ minutes in a vacuum furnace. Homogeneous distribution of Zn particles of size was obtained by the zincate treatment with pH 13 ~ 13.5, solution concentration of 15 ~ 25% at room temperature. The plating rates for both Ni-P and Au electroless plating steps increased with increasing the plating temperature and pH. The main crystallization planes of the plated Au were found to be (111) a pH 7 and (200) and (111) at pH 9 independent of the annealing temperature.

  • PDF

Identification of Microplastics in Sea Salts by Raman Microscopy and FT-IR Microscopy (라만 및 FT-IR 현미경을 이용한 천일염 중 미세플라스틱 분석)

  • Cho, Soo-Ah;Cho, Won-Bo;Kim, Su-Bin;Chung, Jae-Hak;Kim, Hyo-Jin
    • Analytical Science and Technology
    • /
    • v.32 no.6
    • /
    • pp.243-251
    • /
    • 2019
  • Microplastics (MP) are found in large quantities in the oceans, posing a major threat to the ecosystem. In Korea, MPs have been reported to be detected in sea salts. In order to analyze MPs, information on their composition, size, and shape is required. FT-IR microscopy is used frequently to measure sizes larger than 20 ㎛. Recently, however, Raman microscopy, which can analyze ultrafine plastics below 20 ㎛, has been applied extensively. In this study, 10.0 g samples of commercially available salts were dissolved and filtered through a 45 ㎛ mesh filter with a size of 25.4 mm × 25.4 mm. These filtered samples were then analyzed by both FT-IR microscopy and Raman microscopy. A total of four MPs, including three polyethylene (PE) of size 70-100 ㎛ and a polypropylene (PP) of size 170 ㎛, were detected by FT-IR microscopy, while 10 MPs, including nine PE of size 10-120 ㎛ and one polystyrene (PS) of size 40 ㎛, were detected by Raman microscopy. Approximately, 1,000 MPs/kg was estimated, which was almost two times higher than the previous reported levels (~550-681 particles/kg in sea salts); this is because Raman microscopy can detect much smaller MPs than FT-IR microscopy. A total of 113 particles were found using Raman microscopy: Carbon (35, 31.5 %), minerals (28, 25 %), and glass (16, 14.4 %) were dominant, forming around 70% of the total, but MPs (10, 8.8 %) and cellulose (5, 4.5 %) were also found. Raman microscopy has great potential as an accurate method for measuring MPs, as it can measure smaller size MPs than FT-IR microscopy. It also has a reduced sample preparation time.

Spectral Characteristics of Sea Surface Height in the East Sea from Topex/Poseidon Altimeter Data (Topex/Poseidon에서 관측된 동해 해수면의 주기특성 연구)

  • 황종선;민경덕;이준우;원중선;김정우
    • Economic and Environmental Geology
    • /
    • v.34 no.4
    • /
    • pp.375-383
    • /
    • 2001
  • We extracted sea surface heights(SSH) from the TopexJPoseidon(T/P) radar altimeter data to compare with fhe SSH estimated from in-situ lide gauges(T/G) at Ulleungdo, Pohang, and SockcholMucko sites. Selection criteria such as wet/dry troposphere, ionosphere, and ocean tide were used to estimate accurate SSH. For time series analysis, the one-hour interval tide gauge SSHs were resampled al lO-day interval of the satellite SSHs. The ocean tide model applied in the altimeter data processing showed periodic aliasings of 175.5 day, 87.8 day, 62J day, 58.5 day, 49.5 day and 46.0 day, and, hence, the ZOO-day filtering was applied to reduce these spectral noises. Wavenumber correlation analysis was also applied to extract common components between the two SSHs, resulting in enhancing the correlation coefficient(CC) dramatically. The original CCs between the satenite and tide gauge SSHs are 0.46. 0.26, and 0.]5, respectively. Ulleungdo shows the largest cc bec;luase the site is far from the coast resulting in the minimun error in the satellite observations. The CCs were then increased to 0.59, 030, and 0.30, respectively, after 200.day filtering, and to 0.69, 0.63. and 0.59 after removing inversely correlative components using wavenumber correlation analysis. The CCs were greatly increased by 87, 227, and 460% when the wavenumber correlation analysis was followed by 2oo-day filtering, resulting in the final CCs of 0.86, 0.85, 0.84, respectively. It was found that the best SSHs were estimated when the two methods were applied to the original data. The low-pass filtered TIP SSHs were found to be well correlated with the TIG SSHs from tide gauges, and the best correlation results were found when we applied both low-pass filtering and spectral correlation analysis to the original SSHs.

  • PDF

La signification du dépassement de soi dans le Thomisme (토미즘의 인간적 행위에서 '자기초월'의 의미)

  • Lee, Myung-Gon
    • Journal of Korean Philosophical Society
    • /
    • v.105
    • /
    • pp.49-74
    • /
    • 2008
  • Le but de notre recherche est $d^{\prime}{\acute{e}}clairer$ la nature du $d{\acute{e}}passement$ de soi aux actes humaines dnas le Thomisme. Dans le Thomisme la nature humaine qui a la raison et la $volont{\acute{e}}$ a une $intentionnalit{\acute{e}}$ ver la fin ultime. De sorte que les actes humaines qui $corr{\grave{e}}spondent$ cette nature humaine a un $caract{\grave{e}}re$ du $d{\acute{e}}passement$ de soi visant toujours plus que le $pr{\acute{e}}sent$. Le fondement de cet acte du $d{\acute{e}}passement$ de soi est $l^{\prime}{\hat{a}}me$ rationelle qui est la forme substantielle de l'homme et de soi subsistante. Chez st. Thomas ce $caract{\grave{e}}re$ du $d{\acute{e}}passement$ a trois ${\acute{e}}taps$ distinctes : (1)le $d{\acute{e}}passement$ dans l'ordre du $progr{\grave{e}}s$ naturel (2)le $d{\acute{e}}passement$ de soi dans l'ordre morale (3)le $d{\acute{e}}passement$ de soi dans l'ordre de la religion. Le $d{\acute{e}}passement$ dans l'ordre du $progr{\grave{e}}s$ naturel apparaît d'abord au $caract{\grave{e}}re$ de $l^{\prime}{\hat{a}}me$ rationelle. St. Thomas $d{\acute{e}}finit$ les vertus rationelles comme $^{\prime}pl{\acute{e}}nitude$ dans le $f{\acute{e}}blesse$, parce qu'il $consid{\grave{e}}re$ la vertu rationelle comme $finalit{\acute{e}}$ des $facult{\acute{e}}s$ du sens $ext{\acute{e}}rieur$. L'homme par le sens $ext{\acute{e}}rieur$ reçoit des $esp{\grave{e}}ces$ sensibles(especies sensibilis), et $poss{\grave{e}}de$ les images. Puis cette images sensible devenant la $r{\acute{e}}alit{\acute{e}}$ spirituelle sous forme du $m{\acute{e}}moire$ et du souvenir, devient aussi la partie de son existence. Donc chez st. Thomas la vertue rationnelle n'est pas simplement un $facult{\acute{e}}$ $sp{\acute{e}}culative$, mais elle est dans l'ordre du devenir et du $pl{\acute{e}}nitude$. A cette raison st. Thomas compare la raison(ratio) comme $g{\acute{e}}n{\acute{e}}ration$(generatio) et l'intelleigence(intellectus) comme ${\hat{e}}tre$(esse). C'est-${\grave{a}}$-dire la raison $d{\acute{e}}passe$ le sensible et l'intelligence $d{\acute{e}}passe$ la raison. Le $d{\acute{e}}passement$ de soi dans l'ordre morale $li{\acute{e}}$ au $progr{\grave{e}}s$ de la conscience. Chez st. Thomas la perception de l'objet $ext{\acute{e}}rieur$ ayant pour but d'avoir conscience de soi, se perfectionne ${\grave{a}}$ ceci. D'avoir conscience de soi signifie d'avoir $l^{\prime}identit{\acute{e}}$ de soi, et de-$l{\grave{a}}$ apparaît l'acte moral en tnat qu'acte $sp{\acute{e}}cifique$ humain. La raison pour laquelle la vie morale elle-$m{\hat{e}}me$ a un $caract{\grave{e}}$ du $d{\acute{e}}passement$, c'est que l'acte humaine qui corresfonde ${\grave{a}}$ $l^{\prime}identit{\acute{e}}$ du soi est une vie qui vise toujours plus que le $pr{\acute{e}}sent$ ou $l^{\prime}id{\acute{e}}al$. Quant au problem du $d{\acute{e}}passement$ dans l'ordre de la religion, chez st. Thomas en raison de $l^{\prime}affinit{\acute{e}}$ entre Dieu et l'homme, $o{\grave{u}}$ il y a des vertues infuses(virtutes infusas), il y a une sorte du $d{\acute{e}}passement$ religieux. Car ces vertues infuses signifie la communication entre Dieu(${\hat{E}}tre$ absolu) et l'homme(${\hat{e}}tre$ fine) et cela signifie le $d{\acute{e}}passement$ de l'humain vers le divin. Cette $id{\acute{e}}e$ thomiste permet de penser que $o{\grave{u}}$ il y a un $d{\acute{e}}passement$ de soi dans la vie religuse d'une personne, il y a une intervention $r{\acute{e}}elle$ de la providence divine. Cette $pens{\acute{e}}e$ thomiste sera alors un $caract{\grave{e}}$ $r{\acute{e}}aliste$ face ${\grave{a}}$ la $pens{\acute{e}}e$ $id{\acute{e}}aliste$ qui n'admette que le $d{\acute{e}}passement$ absolu comme $d{\acute{e}}passement$ religieux.