Chip Inductor의 기술동향

구기덕 에스케이텔레콤 (주) 1993 Telecommunications Review Vol.3 No.7

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SiO$_2$-TiO$_2$-RO(RO: BaO, CaO, SrO)계 고유전율 유리 제조 및 글라스/세라믹스의 소결 거동에 관한 연구

구기덕,오근호 한국결정성장학회 1998 한국결정성장학회지 Vol.8 No.4

본 연구에서는 고유전율의 저온소성용 글라스/세라믹을 제조하고자, SiO2-TiO2-RO계 결정화 유리를 제조하고 Al2O3를 필러 물질로 혼합하여 복합체를 제조하고 그 특성을 관찰하였다. 본 유리조성으로써 $900^{\circ}C$ 이하에서 결정화되는 유리의 제조가 가능하였고, RO (BaO, CaO, SrO)의 성분에 따라 결정화 온도는 변화함을 알 수 있었다. 본 유리조성에 $Bi_2O_3$를 플럭스로 첨가하고, 세라믹 필러로써 Al2O3를 사용하여 $860^{\circ}C$에서 소성함으로써 고유전율의 저온소성용 글라스/세라믹의 제조가 가능하였고, 이때 복합체의 밀도는 3.96g/$\textrm{cm}^3$ 이었고, 유전율은 17, Q.f 값은 600이었다. For the fabrication of low temperature cofirable glass/ceramic with high dielectric constant, crystallizing glass [$SiO_2-TiO_2-RO (RO:BaO, CaO:SrO)$] was formed. The glass/ceramic composites were made by mixing this glass and alumina ceramic as filler, and its characteristics was investigated. With this glass compositon, it was possible to fabricate the glass which could be crystallized under $900^{\circ}C$. And it was found that the crystallizing temperature was changed in accordance with the composition of RO in glass. By adding $Bi_2O_3$ as flux, using $Al_2O_3$ as filler and sintering at $860^{\circ}C$, low temperature cofirable glass/ceramic with high dielectric constant was fabricated. The density of that composites was 3.96 g/$\textrm{cm}^3$, dielectric constant was 17 and Q. f was 600.

유리 프릿트의 연화점이 저온소성용 글라스/세라믹 복합체의 소결거동에 미치는 영향

구기덕,오근호 한국결정성장학회 1998 韓國結晶成長學會誌 Vol.8 No.4

The effect of softening point and glass amount of glass frit on the sintering behavior of low temperature cofirable glass/ceramic composites was studied and according to these results, glass/ceramic composites with high sintered density was fabricated. The density of composites was increased as the glass amount was increased. In case of using the glass with low softening point, the deformation of specimen was occurred though the ratio of the glass amount in the specimen was low. But, in case of using the glass with high softening point, the sintered density of composites was increased in accordance with glass amount. With the specimen of high softening point, the deformation was not happened. Therefore, it was found that the densification was progressed continuously in high glass amount. From the study on the effect of softening point of glass on sintering behavior, the suitable softening point and glass amount for fabrication of glass/ceramic composites can be anticipated. When glass frit with softening point of $790^{\circ}C$ was chosen according to this result, low temperature cofirable glass/ceramic composites with high density (97%) at $900^{\circ}C$ was fabricated. 저온소성용 글라스/세라믹 복합체 제조시 사용되는 유리 프릿트의 연화점과 유리의 함량이 소결특성에 미치는 영향에 대해 고찰하였고, 이에 따라 고밀도의 저온소성용 글라스/세라믹 복합체를 제조하였다. 유리의 함량이 증가함에 따라 복합체의 소결밀도는 증가하였고, 이때 사용되는 유리의 연화점이 낮을 경우 유리의 함량이 적은 시현의 경우에도 변형이 일어남을 알수 있었다. 유리의 연화점이 높은 유리를 사용한 시편의 경우, 유리의 함량을 증가시켜도 시편의 변형은 일어나지 않았으며, 소결밀도는 계속적으로 증가하여 치밀화가 하고 있음을 알수 있었다. 이러한 유리함량과 유리의 연화점이 소결특성에 미치는 영향을 고찰함으로써 높은 밀도의 동시소성용 글라스/세라믹을 제조할 수 있는 유리의 연화점과 유리함량을 예측할 수 있었고, 이에따라 $790^{\circ}C$의 연화점을 갖는 유리를 유리 프릿트로 사용함으로써 $900^{\circ}C$의 소성온도에서 소결밀도 97%이상의 고밀도의 저온소성용 글라스/세라믹 복합체를 제조할 수 있었다.

다층 세라믹스의 소결 수축율에 대한 Binder Burnout 온도의 영향

성재석,구기덕,윤종광 한국세라믹학회 1996 한국세라믹학회지 Vol.33 No.12

Change of sintering shrinkage in alumina-based multilayer ceramics was observed in various lamination condi-tions and binder burnout (BBO) temperatures. It was found that the linear shrinkages in X and Y directions were nearly the same with the BBO temperatures but a large shrinkage difference in Z direction was observed. However this phenomenon was diminished when BBO temperature was increased. A linear relationship between the laminated density and the sintering shrinkage was found and the slope was independant on the BBO temperature but dependant on the shrinkage direction.

다층세라믹스 제조시 적층 공정 변수에 따른 수축율 조절

성재석,구기덕,윤종광 한국세라믹학회 1996 한국세라믹학회지 Vol.33 No.11

In the fabrication of alumina-based multilayer ceramics sintering shrinkages with lamination conditions such as lamination pressure temperature and laminating with and without press die were compared. The sintering shrinkage was affected substantially by lamination pressure and temperature and in the case of laminatino without press die the lower laminated density and a large difference in shrinkage with direction were observed. These results can be explained by introducing a new factor which is the ratio of the changes of areas before and after lamination.

알루미나/텅스텐 동시소성에 의한 다층 팩키지 제조시 적층조건에 따른 camber의 변화

성재석,구기덕,윤종광,이상진,박정현 한국세라믹학회 1997 한국세라믹학회지 Vol.34 No.6

In cofiring of multilayered alumina with tungsten, the change of camber with lamination condition was experimented and the effect of sintering shrinkage of alumina and tungsten was investigated. From the exact measurement of sintering shrinkage of tungsten thick film, as lamination pressure increased, the sintering shrinkage of alumina decreased but that of tungsten thick film was not changed. So it was though that the main factor which induced the sintering shrinkage difference between ceramics and metal with lamination condition was the change of sintering shrinkage of ceramics. In case of high lamination pressure, high green sheet density, the cofired specimen showed low camber due to low shrinkage difference between alumina and tungsten and there was a linear relation between camber and shrinkage difference. It was found that this shrinkage difference could change the thickness of tungsten film and the microstructure within via hole during cofiring.

알루미나를 첨가한 코디어라이트계 결정화 유리의 소결거동 및 결정화 특성

박정현,노재호,성재석,구기덕 한국세라믹학회 1998 한국세라믹학회지 Vol.35 No.7

The MgO-{{{{ { {Al }_{2 }O }_{3 } }}-{{{{ { {SiO }_{2 } }_{ } }}system containing alumina powder was fabricated sintered at various temperature and analyzed in order to study the sintering mechanism and crystallization characteristics. The specimen composed of glass powder with average particle size of 8.27 $\mu\textrm{m}$ and 0-40 vol% alumina powder were sint-ered for 3 hrs at the temperature between 850$^{\circ}C$ and 1350$^{\circ}C$ The sintering mechanism consists of the redis-tribution of particles occuring at 750$^{\circ}C$ and the viscous flow at 850∼950$^{\circ}C$. The degree of crystallization and sintering temperatue were dependent upon the ratio of glass/alumina. The second phase from the reaction between glass and alumina was not observed which was confirmed by XRD and properties analysis. The density dielectric constant and specific resistivity of specimen were 2.30∼3.26g/cm2 5.8∼7.38 at 1 GHz density dielectric constant and specific resistivity of specimen were 2.30∼3.26g/cm3 5.8∼7.38 at 1GHz and 1.23∼4.70${\times}$107 $\Omega$$.$m respectively.

Alumina Green Sheet의 동시소성용 텅스텐 페이스트 제조 및 금속 접합에 관한 연구

이준,박경리,윤종광,구기덕 한국마이크로전자및패키징학회 1996 하이브리드마이크로일렉트로닉스 Vol.3 No.2

In order to develop a tungsten metallizing paste well fitted to a specific alumina green sheet, series of pastes were formulated in conjunction with particle size of tungsten powder, content and composition of glass frits and organic vehicles. The pastes were screen printed on the alumina green sheet and fired in wet hydrogen atmosphere at 1540 ℃. After the printed substrates were fired, various properties, such as adhesion strength between the tungsten film and alumina substrate, camber of the substrate, were examined and evaluated in concerned with their microstructural morphologies. As the results of experiments examining the applicability of tungsten particle size, a paste having tungsten powder of 1.9㎛ particle showed the most favorable adhesion strength and shrinkage matching. Moreover, two pastes formulated with two frits of MgO·0.39 Al₂O₃·0.67Si₂ and CaO·1.1 Al₂O₃·0.9SiO₂ among 14 glass frits were fairly better in improving the adhesion strength of the metallization and the maximum adhesion strength were obtained at the content of the frits as following formula.

고주파용 저온 동시소성 세라믹(LTCC)칩 커플러 제조: II. Ag 이온 확산에 대한 소결공정의 영향

이선우,김경훈,심광보,구기덕 한국세라믹학회 1999 한국세라믹학회지 Vol.36 No.5

The sintering behavior of LTCC (low temperature cofired ceramics) chip couplers was investigated in relation with Ag diffusion at the interface of glass ceramic substrate-Ag electrode. Sintering temperature was in the range of 825$^{\circ}C$-975$^{\circ}C$. The commercial green sheet and silver electrode were used. Below 875$^{\circ}C$ the diffusion of the Ag ion into the substrate and the penetration of glassy phases into the electrode occurred due to an increase of fluidity. Thus the lectrode line was severely deformed and damaged. At 975$^{\circ}C$ the transformation of crystalline phases into glassy phases and the melting of the Ag electrode resulted in the diffusion of the considerable amount of Ag ions.

고주파용 저온 동시소성 세라믹(LTCC)칩 커플러 제조: I. 전극형성에 대한 결합제 분해공정의 영향

조남태,심광보,이선우,구기덕 한국세라믹학회 1999 한국세라믹학회지 Vol.36 No.6

In the fabrication of ceramic chip couples for high frequency application such as the mobile communication equipment the formation of electrode lines and Ag diffusion were investigated with heat treatment conditions for removing organic binders. The deformation and densification of the electrode line greatly depended on the binder burnout process due to the overlapped temperature zone near 400$^{\circ}C$ of the binder dissociation and the solid phase sintering of the silver electrode. Ag ions were diffused into the glass ceramic substrate. The Ag diffusion was led by the glassy phase containing Pb ions rather than by the crystalline phase containing Ca ions. The fact suggests that the Ag diffusion could be controlled by managing the composition of the glass ceramic substrate.