• Proceedings of the KIEE Conference
• /
• 2006.10a
• /
• pp.75-76
• /
• 2006

최근 고주파 유전체 소재로 많이 연구가 되고 있는 $BaSrTiO_3$ 소재와 polymer계열을 이용한 composite복합체를 이용하여 embedded capacitor를 제작하였으며, 후막을 제작하기 위한 방법으로는 두께의 신뢰성이 비교적 높은 screen printing기법을 사용하여 제작하였다. 제작된 소자의 온도별, 주파수별 특성을 연구하여 그 응용 가능성을 알아보았다.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.3
• /
• pp.180-187
• /
• 2004

A conventional power supply of a microwave oven has a 60Hz transformer and high voltage capacitor(HVC). Though it is very simple and has low cost, it has several problems such as large size, heavy weight and low efficiency To improve these problems, various high frequency inverter type power supply have been investigated and developed in recent years. But these cost is higher than the conventional one due to additional control circuit, fast switching devces. In this paper, a novel pulse power supply for microwave oven using high frequency transformer embedded HVC(High Voltage Capacitor) is proposed for down-sizing, cost reduction and efficient improvement. To verify the effectiveness of the proposed transformer, an equivalent circuit of transformer embedded HVC is derived and it's characteristic is described. And the validity of the proposed pulse power supply embedded HVC-high frequency transformer is shown by simulations and experiments accroding to various operating conditions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.4
• /
• pp.342-347
• /
• 2007

$Bi_6Mg_2Nb_4O_{21}(BMN)$ thin films were deposited at various substrates by sputtering system for embedded capacitor applications. BMN thin films deposited at room temperature are manufactured as MIM(Metal/Insulator/Metal) structures. Dielectric properties and leakage current density were investigated as a function of various substrates and thickness of BMN thin films. Leakage current density of BMN thin films deposited on CCL(Copper Clad Laminates) showed relatively high value ($1{\times}10^{-3}A/cm^2$) at an applied field of 300 kV/cm on substrates, possibly due to relatively high value of roughness(rms $50{\AA}$) of CCL substrates. 100 nm-thick BMN thin films deposited on Cu/Ti/Si substrates showed the capacitance density of $300 nF/cm^2$, a dielectric constant of 32, a dielectric loss of 2 % at 100 kHz and the leakage current density of $1{\times}10^{-6}A/cm^2$ at an applied field of 300 kV/cm. BMN capacitors are expected to be promising candidates as embedded capacitors for printed circuit board(PCB).

• The Optical Journal
• /
• s.117
• /
• pp.23-25
• /
• 2008

RF embedded 기판의 기술은 Module과 Package라는 응용 제품을 거치면서 최종적으로는 기존의 여러 가지 제품의 Mother Board(특히 휴대폰)에 접목 시키기 위한 노력이 계속 진행되고 있다. 업계 및 Research 기관의 조사 결과에 따르면 PCB 시장의 성장세와 맞물려 Embedded 시장규모는 큰 폭의 상승이 예상된다. 본 고에서는 높은 유전율을 가지는 강유전체 물질의 Embedded capacitor 적용을 위해 레이저 기술을 전자부품 제조현장에 적용하는 연구의 진행상황을 소개하고자 한다.

• Journal of the Microelectronics and Packaging Society
• /
• v.11 no.1
• /
• pp.87-96
• /
• 2004

Polymer/ceramic composites are the most promising embedded capacitor material for organic substrates application. Predicting the effective dielectric constant of polymer/ceramic composites is very important for design of composite materials. In this paper, we measured the dielectric constant of epoxy/$BaTiO_3$ composite embedded capacitor films with various $BaTiO_3$ particles loading for 5 different sizes $BaTiO_3$ powders. Experimental data were fitted to several theoretical equations to find the equation useful for the prediction of the effective dielectric constant of polymer/ceramic composites and also to estimate the dielectric constant of $BaTiO_3$ powders. The Lichtenecker equation and the Jayasundere-Smith equation were useful for the prediction of the effective dielectric constant of epoxy/$BaTiO_3$ composites. And calculated dielectric constants of the $BaTiO_3$ powders were in the range of 100 to 600, which were lower than those of $BaTiO_3$ bulk ceramics.

• Transactions on Electrical and Electronic Materials
• /
• v.8 no.2
• /
• pp.84-88
• /
• 2007

[ $Bi_{1.5}Zn_{1.0}Nb_{1.5}O_7$ ] (BZN), $Bi_2Mg_{2/3}Nb_{4/3}O_7$ (BMN), and $Bi_2Cu_{2/3}Nb_{4/3}O_7$ (BCN) pyrochlore thin films were prepared on $Cu/Ti/SiO_2/Si$ substrates by pulsed laser deposition and the micro-structural and electrical properties were characterized for embedded capacitor applications. The BZN, BMN, and BCN films deposited at $25\;^{\circ}C$ and $150\;^{\circ}C$, respectively show smooth surface morphologies and dielectric constants of about $39\;{\sim}\;58$. The high dielectric loss of the films deposited at $150\;^{\circ}C$ compared with films deposited at $25\;^{\circ}C$ was attributed to the defects existing at interface between the films and copper electrode by an oxidation of copper bottom electrode. The leakage current densities and breakdown voltages in 200 nm thick-BMN and BZN films deposited at $150\;^{\circ}C$ are approximately $2.5\;{\times}\;10^{-8}\;A/cm^2$ at 3 V and above 10 V, respectively. Both BZN and BMN films are considered to be suitable materials for embedded capacitor applications.

• Journal of the Microelectronics and Packaging Society
• /
• v.8 no.4
• /
• pp.59-65
• /
• 2001

Epoxy/$BaTiO_3$composite capacitor films with excellent stability at room temperature, uniform thickness, and electrical properties over a large area ware successfully fabricated. The composite capacitor films with good film formation capability and easy process ability were made from epoxy resin developed for ACF as a matrix and two kinds of $BaTiO_3$powders as fillers to increase the dielectric constant of the composite film. The crystal structure of the powders and its effects on dielectric constant of the films were investigated by X-ray diffraction (XRD). And the optimum amount of dispersant, phosphate ester, was determined by viscosity measurement of suspension. DSC and dielectric property tests were conducted to decide the right curing temperature and the optimum amount of the curing agent. As a result, the capacitors of 7 $\mu \textrm{m}$ thick film with 10 nF/$\textrm{cm}^2$ and low leakage current were successfully demonstrated.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2001.11a
• /
• pp.21-27
• /
• 2001

Epoxy/BaTiO$_3$composite film type capacitors with excellent stability at room temperature, uniform thickness, and electrical properties over a large area were successfully fabricated. We fabricated composite capacitor films with good film formation capability and easy process ability, from ACF-resin as a matrix and two kinds of BaTiO$_3$powders as fillers to increase the dielectric constant of the composite film. The crystal structure of the powders and its effects on dielectric constant of the films were investigated by X-ray diffraction. DSC and dielectric properties tests were conducted to decide the right curing temperature and the optimum amount of the curing agent. As a result, the capacitors of $7{\mu}{\textrm}{m}$ thick film with 10nF/cm2 and low leakage current were successfully demonstrated.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.4
• /
• pp.918-923
• /
• 2008

We proposed an embedded capacitor with the unique electrode structure, which electrodes are located on the same plane and dielectric gap was formed by electrodes. We named it 'Gap type EC', and it was analyzed by the FEM(Finite element Method) program tool. The resonant frequency of Cap type EC was obtained at more higher frequency region. Also, resonant frequency was changed with the magnitude and thickness of electrodes. The Gap type EC with the dielectric gap of $50{\mu}m$ showed capacitance density of $55pF/cm^2$. This value is the higher than that of conventional EC. So, we concluded that the Gap type EC can be a good candidate for high frequency decoupling.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.342-345
• /
• 2002

As the size of chip components and module decreases, new patteming method for fine line and geometry is needed. So far, in LTCC(Low Temperature Cofired Ceramic) process, screen printing method has been used generally. But screen printing method has some disadvantages as follows. First, the geometry including line, vias, etc. smaller than $100{\mu}m$ can't be evaluated easily. Second, the patterned dimension is different from designed value, which makes distortion in charactersitics of not only chip components but also modules. Thick film lithography has advantages of thick film screen printing process, low cost and thin film process, fine line feasibility. Using this method, the line with $30{\mu}m$ width and the geometry with expected dimension can be evaluated. In this study, the fine line with $35{\mu}m$ line/space is formed and the embedded capacitor with very small tolerance is developed using thick film lithography.