Inductively coupled plasma reactive ion etching (ICP-RIE) of copper thin films patterned with SiO₂ hard masks was carried out using piperidine/O₂/Ar gas mixture. The etch rate, etch selectivity, and etch profile of copper thin films were investigated by varying gas concentration in piperidine/O₂/Ar gas mixture. In addition, the etch parameters including ICP RF power, DC-bias voltage to substrate, and process pressure were varied to examine the etch characteristics. X-ray photoelectron spectroscopy and optical emission spectroscopy were employed to elucidate the etch mechanism under piperidine/O₂/Ar gas chemistry. Finally, 150 nm-line patterned copper thin films were successfully etched using piperidine/ O₂/Ar etch gas under the optimized etch conditions.

Lithium-ion batteries used for IT, automobiles, and industrial energy-storage devices have battery management systems (BMS) to protect the battery from abnormal voltage, current, and temperature environments, as well as safety devices like, current interruption device (CID), fuse, and vent to obtain positive temperature coefficient (PTC). Nonetheless, there are harmful to human health and property and damage the brand image of the manufacturer because of smoke, fire, and explosion of lithium battery packs. In this paper, we propose a systematic protection algorithm combining battery temperature, over-current, and interconnection between protection elements to prevent copper deposition, internal short circuit, and separator shrinkage due to frequent and instantaneous over-current discharges. The parameters of the proposed algorithm are suggested to utilize the experimental data in consideration of battery pack operating conditions and malicious conditions.

This work reports the surface morphology and transmittance of copper oxide thin films for semitransparent solar cell applications. We prepared the oxide specimens by subjecting copper thin films to an oxidation reaction at annealing temperatures ranging between 100℃ and 300℃. The color of the as-deposited specimen was red, but changed to purple at the annealing temperature of 300℃. The surface morphology and transmittance of the specimens were significantly dependent on the annealing temperature and thickness of the copper films. Copper oxide nanoparticles prepared from a 20-nm-thick copper film at an annealing temperature of 300℃ provided a maximum transmittance of 93%. The obtained optical characteristics and surface morphology suggest that copper oxide thin films prepared by an oxidation reaction can be potentially employed as color- and transmittance-adjusting layer in semitransparent thin solar cells.

The effect of particle sizes on the aerosol deposition (AD) of Cu films is investigated in order to understand the deposition behaviors of metal powder during the AD process. The Cu coatings fabricated by using 2 μm Cu powders had a dense microstructure, a high deposition rate (1.6 ± 0.2 μm/min), and low resistance (9.42 ± 0.4 μΩ·cm) compared to that from using Cu powder with a particle size greater than 5 μm. Also, from estimating the internal micro-strain of Cu films, the Cu coatings fabricated by using 2 μm Cu particles exhibited a high micro-strain value of 3.307×10^-3. On the other hand, the strain of Cu coatings fabricated with 5 μm particles was decreased to 2.76×10^-3. These results seem to show that the impacted Cu particles are compressed and flattened by shock waves, and that their bonding is associated with the high internal micro-strain caused by plastic deformation.

In this paper, we designed and fabricated low cost imprinting process for micro patterning on FCCL (flexible copper clad laminate). Compared to conventional imprinting process, developed fabrication method processing imprint and UV photolithography step simultaneously and it does not require resin etch process and it can also reduce the fabrication cost and processing time. Based on proposed method, patterns with 10 ㎛ linewidth are fabricated on 180 ㎜ × 180 ㎜ FCCL. Compared to conventional methods using LDI (laser direct imaging) equipment that showed minimum line with 10 ∼ 20 ㎛, proposed method shows comparable pattern resolution with very competitive price and shorter processing time. In terms of mass production, it can be applied to fabrication of large-area low cost applications including FPCB.

Copper manganite thin films were fabricated on SiNx/Si substrate by metal organic decomposition (MOD) process. They were burned-out at 400℃ and annealed at various temperatures (400∼800℃) for 1h in ambient atmosphere. Their micro-structure and negative temperature coefficient of resistance (NTCR) characteristics were analyzed for micro-bolometer application. The copper manganitefilm with a cubic spinel structure was well developed at 500℃ which confirmed by XRD and HRTEM analysis. It showed a low resistivity (47.5 Ω·cm) at room temperature and high NTCR characteristics of-4.12%/℃ and -2.15%/℃ at room temperature and 85℃, implying a good thin film for micro-bolometer application. Furthermore, its crystallinity was enhanced with increasing temperature to 600℃. However, the appearance of secondary phase at temperatures higher than 600℃ lead to deteriorate the NTCR characteristics.

We investigated the luminescence properties of Alq3 in the device structure of ITO/CuPc/TPD/Alq3/Al. The CuPc as a hole-injection material and TPD as hole-transport material. Emission properties were measured by varying a layer thickness of CuPc (0 nm to 50 nm), which is the hole-injection layer. As a result, it was found that the hole injection occurs smoothly when the layer thickness was 20 nm among the thicknesses from 0 nm to 50 nm.

In this study, the surface modification of copper foil using an inductively coupled O2 / Ar plasma as O2 gas fraction (0∼100%) was investigated in order to improve the surface characteristics. After plasma treatment, the measurement of the surface roughness, surface contact angle and surface energy were performed for the surface analysis of copper foil. As a result, the surface roughness and the surface energy were increased. And plasma diagnostics was performed by a double Langmuir probe (DLP) and optical emission spectroscopy (OES). Using these results, the plasma surface modification mechanism was investigated.

This paper carried out the comparative analysis on ground impedance of a carbon block and a copper rod. Two types of grounding electrode were compared; a carbon block (L: 1 m, ф : 245 mm)buried at depth of 0.8m and a three-linked copper rod (L : 1 m, : ф : 10 mm) of equilateral triangles with 1 m spacing. Ground impedance depending on applied current was evaluated by the application of a sine wave current with 60 Hz~3.5 MHz, fast-rise pulse with rising time of 200 ns, a standard lightning impulse of 8/20 ㎲ and a 600 Hz square wave. Ground impedance for both electrodes were almost the value below 100 KHz, and increased rapidly afterwards. The maximum ground impedance appeared 400 Ω at around 1.5 MHz. Ground impedance of the block was lower at the square wave and was higher at fast-rise pulse that of the copper rod. Also, impedance as ages showed no difference for the 8 months. From the results, it is likely that ground performance for both electrodes shows no difference against commercial frequency and lighting impulse current, while the copper rod shows better performance against fast-rise pulse with rise-time of a few hundred ns.

Thin light-active layers of the CuInSe2 solar cell were prepared on Mo-coated sodalime glass substrates by one-step electrodeposition and post-annealing. The structure, morphology, and composition of CuInSe2 film could be controlled by deposition parameters, such as the composition of metallic precursors, the concentration of complexing agents, and the temperature of post-annealing with elemental selenium. A dense and uniform Cu-poor CuInSe2 film was successfully obtained in a range of parametric variation of electrodeposition with a constant voltage of -0.5 V vs. a Ag/AgCl reference electrode. The post-annealing of the film at high temperature above 500℃ induced crystallization of CuInSe2 with well-developed grains. The KCN-treatment of the annealed CuInSe2 films further induced Cu-poor CuInSe2 films without secondary phases, such as Cu2Se. The structure, morphology, and composition of CuInSe2 films were compared with respect to the conditions of electrodeposition and post-annealing using SEM, XRD, Raman, AES and EDS analysis. And the conditions for preparing device-quality CuInSe2 films by electrodeposition were proposed.

In this paper, thermal analysis of heatsink for 30 W class Chip-on-Board (COB) LED light source is performed by using SolidWorks Flow Simulation package. In order to increase the convection heat transfer, number of fin and shape of the heatsink is optimized. Furthermore, a copper spread is applied between the COB LED light source and the heatsink to mitigate the heat concentration on the heatsink. With the copper spread, the junction temperature between the COB LED light source and the heatsink is 5O.9℃, which is 5.4℃ lower than the heatsink without the copper spread. Due to the improvement of the junction temperature, the light output is improved by 5.8% when the LED light source is stabilized. The temperature difference between the simulation and measured result of the heatsink with the copper spread is within 2℃, which verifies the validity of the thermal design method using a simulation package.

Modified structure of copper pillar bump which has trapezoidal cross section on the top region is suggested with simulation results and concept of fabrication process. Due to the large surface area of joint region between bump and solder in suggested structure, electro-migration effect can be reduced. Reduction of electro-migration is related with current density and joule heating in bump and investigated with finite element methods with variation of dimensional parameters. Mechanical characteristics are also investigated with comparing modified copper pillar bump and conventional copper pillar bump.

The use of plated front contact for metallization of silicon solar cell may alternative technologies as a screen printed and silver paste contact. This technologies should allow the formation of contact with low contact resistivity a high line conductivity and also reduction of shading losses. A selective emitter structure with highly dopes regions underneath the metal contacts, is widely known to be one of the most promising high-efficiency solution in solar cell processing. When fabricated Ni/Cu plating metallization cell with a selective emitter structure, it has been shown that efficiencies of up to 18% have been achieved using this technology.

Copper (Cu) had been attractive material due to its superior properties comparing to other metals such as aluminum or tungsten and considered as the best metal which can replace them as an interconnect metal in integrated circuits. CMP (Chemical Mechanical Polishing) technology enabled the production of excellent local and global planarization of microelectronic materials, which allow high resolution of photolithography process. Cu CMP is a complex removal process performed by chemical reaction and mechanical abrasion, which can make defects of its own such as a scratch, particle and dishing. The abrasive particles remain on the Cu surface, and become contaminations to make device yield and performance deteriorate. To remove the particle, buffing cleaning method used in post-CMP cleaning and buffing is the one of the most effective physical cleaning process. AE(Acoustic Emission) sensor was used to detect dynamic friction during the buffing process. When polishing is started, the sensor starts to be loaded and produces an electrical charge that is directly proportional to the applied force. Cleaning efficiency of Cu surface were measured by FE-SEM and AFM during the buffing process. The experimental result showed that particles removed with buffing process, it is possible to detect the particle removal efficiency through obtained signal by the AE sensor.

Copper pillar tin bump (CPTB) was developed for high density chip interconnect technology. Copper pillar tin bumps that have 100μm pitch were introduced with fabrication process using a KM-1250 dry film photoresist (DFR), copper electroplating method and Sn electro-less plating method. Mechanical shear strength measurements were introduced to characterize the bonding process as a function of thermo-compression. Shear strength has maximum value with 330℃ and 500 N thermo-compression process. Through the simulation work, it was proved that when the copper pillar tin bump decreased in its size, it was largely affected by the copper oxidation.