다층 세라믹 패키지 재료와 제조공정

오태성 ( Tae Sung Oh ) 대한금속재료학회 1992 大韓金屬學會會報 Vol.5 No.2

가압소결온도에 따른 p형 (Bi_0.2Sb_0.8)₂Te₃ 가압소결체의 열전특성

최정열,오태성,Choi, Jung-Yeol,Oh, Tae-Sung 한국마이크로전자및패키징학회 2011 마이크로전자 및 패키징학회지 Vol.18 No.4

The p-type $(Bi_{0.2}Sb_{0.8})_2Te_3$ powers were fabricated by mechanical alloying and hot-pressed at temperatures of $350{\sim}550^{\circ}C$. Themoelectric properties of the hot-pressed $(Bi_{0.2}Sb_{0.8})_2Te_3$ were characterized as a function of the hot-pressing temperature. With increasing the hot-pressing temperature from $350^{\circ}C$ to $550^{\circ}C$, the Seebeck coefficient and the electrical resistivity decreased from 237 ${\mu}V/K$ to 210 ${\mu}V/K$ and 2.25 $m{\Omega}-cm$ to 1.34 $m{\Omega}-cm$, respectively. The power factor of the hot-pressed $(Bi_{0.2}Sb_{0.8})_2Te_3$ became larger from $24.95{\times}10^{-4}W/m-K^2$ to $32.85{\times}10^{-4}W/m-K^2$ with increasing the hot-pressing temperature from $350^{\circ}C$ to $550^{\circ}C$. Among the specimens hot-pressed at $350{\sim}550^{\circ}C$, the $(Bi_{0.2}Sb_{0.8})_2Te_3$ hot-pressed at $500^{\circ}C$ exhibited the maximum dimensionless figure-of-merit of 1.09 at $25^{\circ}C$ and 1.2 at $75^{\circ}C$.

전기도금 공정으로 제조한 Bi-Te 박막의 열전특성 및 미세열전소자 형성용 포토레지스트 공정

이광용,오태성,Lee, Kwang-Yong,Oh, Tae-Sung 한국마이크로전자및패키징학회 2007 마이크로전자 및 패키징학회지 Vol.14 No.2

Thermoelectric properties of the electrodeposited Bi-Te films and photoresist process have been investigated to apply for thermoelectric thin film devices. After plating in Bi-Te solutions of 20 mM concentration, which were prepared by dissolving $Bi_2O_3$ and $TeO_2$ into 1M $HNO_3$, thermoelectric properties of the films were characterized with variation of the Te/(Bi+Te) ratio in a plating solution. With increasing the Te/(Bi+Te) ratio in the plating solution from 0.5 to 0.65, Seebeck coefficient of Bi-Te films changed from $-59{\mu}V/K$ to $-48{\mu}V/K$ and electrical resistivity was lowered from $1m{\Omega}-cm$ to $0.8m{\Omega}-cm$ due to the increase in the electron concentration. Maximum power factor of $3.5{\times}10^{-4}W/K^2-m$ was obtained for the Bi-Te film with the $Bi_2Te_3$ stoichiometric composition. Using multilayer overhang process, the photoresist pattern to form thermoelectric legs of 30 m depth and 100m diameter was successfully fabricated fur micro thermoelectric device applications.

칩 스택 패키지에 적용을 위한 Rotating Disc Electrode의 회전속도에 따른 Cu Via Filling 특성 분석

이광용,오태성,Lee, Kwang-Yong,Oh, Tae-Sung 한국마이크로전자및패키징학회 2007 마이크로전자 및 패키징학회지 Vol.14 No.3

For chip-stack package applications, Cu filling characteristics into trench vias of $75{\sim}10\;{\mu}m$ width and 3 mm length were investigated with variations of the electroplating current density and the speed of a rotating disc electrode (RDE). Cu filling characteristics into trench vias were improved with increasing the RDE speed. There was a Nernst relationship between half width of trench vias of Cu filling ratio higher than 95% and the minimum RDE speed, and the half width of trenches with 95% Cu filling ratio was linearly proportional to the reciprocal of root of the minimum RED speed.

Under Bump Metallurgy의 종류와 리플로우 시간에 따른 Sn 솔더 계면반응

박선희,오태성,Park, Sun-Hee,Oh, Tae-Sung,Englemann, G. 한국마이크로전자및패키징학회 2007 마이크로전자 및 패키징학회지 Vol.14 No.3

Thickness of intermetallic compounds and consumption rates of under bump metallurgies (UBMs) were investigated in wafer-level solder bumping with variations of UBM materials and reflow times. In the case of Cu UBM, $0.6\;{\mu}m-thick$ intermetallic compound layer was formed before reflow of Sn solder, and the average thickness of the intermetallic compound layer increased to $4\;{\mu}m$ by reflowing at $250^{\circ}C$ for 450 sec. On the contrary, the intermetallic layer had a thickness of $0.2\;{\mu}m$ on Ni UBM before reflow and it grew to $1.7\;{\mu}m$ thickness with reflowing for 450 sec. While the consumption rates of Cu UBM were 100nm/sec fur 15-sec reflow and 4.50-sec for 450-sec reflow, those of Ni UBM decreased to 28.7 nm/sec for 15-sec reflow and 1.82 nm/sec for 450-sec reflow.

Si 칩에 형성된 박막히터를 이용한 Chip-on-Glass 공정

정부양,오태성,Jung, Boo-Yang,Oh, Tae-Sung 한국마이크로전자및패키징학회 2007 마이크로전자 및 패키징학회지 Vol.14 No.3

New Chip-on-glass technology to attach an Si chip directly on the glass substrate of LCD panel was studied with local heating method of the Si chip by using thin film heater fabricated on the Si chip. Square-shaped Cu thin film heater with the width of $150\;{\mu}m$, thickness of $0.8\;{\mu}m$, and total length of 12.15 mm was sputter-deposited on the $5\;mm{\times}5\;mm$ Si chip. With applying current of 0.9A for 60 sec to the Cu thin film heater, COG bonding of a Si chip to a glass substrate was successfully accomplished with reflowing the Sn-3.5Ag solder bumps on the Si chip.

리플로우 조건에 따른 Sn-52In 솔더범프의 전단응력과 전단에너지 비교

최재훈,오태성,Choi Jae-Hoon,Oh Tae-Sung 한국마이크로전자및패키징학회 2005 마이크로전자 및 패키징학회지 Vol.12 No.4

Comparison of shear strength and shear energy of the 48Sn-52In solder bumps reflowed on Cu UBM were made with variations of reflow temperature from $150^{\circ}C$ to $250^{\circ}C$ and reflow time from 1 min to 20 min to establish an evaluation method for the mechanical reliability of solder bumps. Compared to the shear strength, the shear energy of the Sn-52In solder bumps was much more consistent with the solder reaction behavior and the fracture mode at the Sn-52In/Cu interface, indicating that the bump shear energy can be used as an effective tool to evaluate the mechanical integrity of solder/UBM interface.

도금전류밀도 및 도금액 온도에 따른 비시안계 Au 범프의 표면 형상과 높이 분포도

최은경,오태성,Choi, Eun-Kyung,Oh, Tae-Sung,Englemann, G. 한국마이크로전자및패키징학회 2006 마이크로전자 및 패키징학회지 Vol.13 No.4

Surface roughness and wafer-level thickness distribution of the non-cyanide Au bumps were characterized with variations of the electroplating current density and the bath temperature. The Au bumps, electroplated at $3mA/cm^{2}\;and\;5mA/cm^{2}$, exhibited the surface roughness of $80{\sim}100nm$ without depending on the bath temperature of $40^{\circ}C\;and\;60^{\circ}C$. The Au bumps, electroplated with $8mA/cm^{2}$ at $40^{\circ}C\;and60^{\circ}C$, exhibited the surface roughness of 800nm and $80{\sim}100nm$, respectively. Wafer-level thickness deviation of the Au bumps became larger with increasing the current density from $3mA/cm^{2}\;to\;8mA/cm^{2}$. More uniform thickness distribution of the Au bumps was obtained at a bath temperature of $60^{\circ}C$ than that of $40^{\circ}C$.

0.05wt% $SbI_3$를 첨가한 n형 $Bi_2({Te_{0.95}}{Se_{0.05}})_3$ 가압소결체의 열처리 시간에 따른 열전특성

이선경,오태성,현도빈,Lee, Sun-Kyong,Oh, Tae-Sung,Hyun, Dow-Bin 한국재료학회 2000 한국재료학회지 Vol.10 No.4

Thermoelectric properties of the 0.05wt% $SbI_3$-doped n-type $Bi_2(Te_{0.95}Se_{0.05})_3$ alloy, prepared by melting/grinding and hot pressing, were investigated with variation of the annealing time up to 36 hours. The electron concentration of the 0.05wt% SbI$_3$-doped n-type $Bi_2(Te_{0.95}Se_{0.05})_3$ alloy decreased with increasing the annealing time. The figure-of-merit of the 0.05wt% $SbI_3$-doped n-type $Bi_2(Te_{0.95}Se_{0.05})_3$ alloy was improved from $2.1{\times}10^{-3}/K$ to $2.35{\times}10^{-3}/K$ by annealing at $500^{\circ}C$ for 3 hours. When annealed longer than 12 hours, however, the figure-of-merit decreased substantially due to the increase of the electrical resistivity.

$Bi_{2}Se_{3}$ 함량에 따른 Bi$_{2}$(Te$_{1-x}$Se$_{ x}$)$_{3}$

김희정,오태성,현도빈,Kim, Hee-Jeong,Oh, Tae-Sung,Hyun, Do-Bin 한국재료학회 1998 한국재료학회지 Vol.8 No.5

Thermoelectric properties of Bi$_{2}$(Te$_{1-x}$Se$_{ x}$)$_{3}$(0.05$\leq$x$\leq$0.25) prepared by mechanical alloying and hot pressing, were investigated. Contrary to the p-type behavior of single crystals, the hot-pressed Bi$_{2}$(Te$_{1-x}$Se$_{ x}$)$_{3}$ exhibited ntype conduction without addition of donor dopant. When $Bi_2(Te_{0.85}Se_{0.15})_3$powders were annealed in (50% $H_2$ + 50% Ar) atmosphere, the hot-pressed specimen exhibited a positive Seebeck coefficient due to the reduction of the electron concentration by removal of the oxide layer on the powder surface and annealing-out of the excess Te vacancies. Among the Bi$_{2}$(Te$_{1-x}$Se$_{ x}$)$_{3}$fabricated by mechanical alloying and hot pressing, $Bi_2(Te_{0.85}Se_{0.15})_3$ exhibited a maximum figure-of-merit of 1.92 $\times$ $lO^{-3}$/K.