With the increasing demand for electronic products, the amount of multilayer ceramic capacitor (MLCC) waste has also increased. Recycling technology has recently gained attention because it can simultaneously address raw material supply and waste disposal issues. However, research on recovering valuable metals from MLCCs and converting the recovered metals into high-value-added materials remains insufficient. Herein, we describe an electrospinning (E-spinning) process to recover nickel from MLCCs and modulate the morphology of the recovered nickel oxide particles. The nickel oxalate powder was recovered using organic acid leaching and precipitation. Nickel oxide nanoparticles were prepared via heat treatment and ultrasonic milling. A mixture of nickel oxide particles and polyvinylpyrrolidone (PVP) was used as the E-spinning solution. A PVP/NiO nanowire composite was fabricated via Espinning, and a nickel oxide nanowire with a network structure was manufactured through calcination. The nanowire diameters and morphologies are discussed based on the nickel oxide content in the E-spinning solution.

The MLCC electronic materials are used to make many industrial parts, for instance, such as smart phone, radio, LCD TV and so on. The screen ways and the rotor ways are known as methods that form electrode in MLCC. In these days, rotor ways have been frequently utilized because of its stability of quality. In this study, mixing characteristics for the inside of barrel of planetary mixer driver were investigated by numerical analysis using k-ε model of unsteady state, including effects for rotation and revolution. As the results, it showed that the flow of radius direction was mixed with regular pattern depending on time, however, the flow of longitudinal direction was mixed with same pattern regardless of time.

During sintering of Ni-electrode multi-layer ceramic capacitors (MLCCs), the Ni electrode often becomes discontinuous because of its lower sintering temperature relative to that of BaTiO3. In an attempt to retard the sintering of Ni, we introduced passivation of the Ni powder. To find the optimal passivation conditions, a thermogravimetric analysis (TGA) was conducted in air. After passivation at 250oC for 11 h in air, a nickel oxide shell with a thickness of 4- 5 nm was formed on nickel nanoparticles of 180 nm size. As anticipated, densification of the compacts of the passivated Ni/NiO core-shell powder was retarded: the starting temperature of densification increased from ~400oC to ~600oC in a 97N2-3H2 (vol %) atmosphere. Grain growth was also retarded during sintering at temperatures of 750 and 1000oC. When the sintering atmosphere was changed from wet 99.93N2-0.07H2 to wet 99.98N2-0.02H2, the average grain size decreased at the same sintering temperature. The conductivity of the passivated powder sample sintered at 1150oC for 8 h in wet 99.93N2-0.07H2 was measured to be 3.9 × 104 S/cm, which is comparable with that, 4.6 × 104 S/ cm, of the Ni powder compact without passivation. These results demonstrate that passivation of Ni is a viable means of retarding sintering of a Ni electrode and hence improving its continuity in the fabrication of BaTiO3-based multi-layer ceramic capacitors.

In this study, the feasible test for the mechanical property characterization of ceramics and multi-layer ceramic capacitor(MLCC) was performed with nanoindentation technique. In case of ceramics, hardness and elastic modulus are dependent on the densification of specimen showing the highest hardness and elastic modulus values of 12.3 GPa and 155 GPa, respectively at . In case of MLCC chip, hardness of dielectric layer was lower than that of margin region. The nanoindentation method could be useful tool for the measurement of mechanical property within dielectric layer of very thin thickness in high capacitance MLCC

고순도 니켈 금속염으로부터 미세하고 입도가 균일한 니켈 분말 직접 제조 연구를 수행하였다. 구형의 형상을 갖는 미세한 니켈 분말을 제조하기 위하여 입도제어가 가능한 슬러리환원법을 사용하였다. 제조된 니켈 분말에 화학성분, 입도, X선회절, 주사전자현미경 분석을 실시하여 니켈 분말의 특성을 조사하였다. 환원제로 하이드라진(hydrazine)을 사용하고, 4.5 M NaOH에서 90분 반응시켜 약 100~200 nm의 입도를 가진 분산도가 양호한 구형의 니켈 분말을 제조할 수 있었다.