• Resources Recycling
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• v.28 no.1
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• pp.3-14
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• 2019

Copper is used in many electronic components and construction parts due to its excellent electrical conductivity and heat transfer characteristics, and also used for pre-plating for double layer coating such as nickel, so that copper is an essential material in modern industry. Despite the expected increase of usage and importance on wiring, sensors and data equipment in the next generation industries, it is hard for securing stable copper supply and resource management resulting from the copper prices are fluctuating owing to the economic crisis in Europe, the low economic growth trend in China, and President Trump's commitment to public industrial facilities investment in U.S.. Since most of the domestic copper consumption is used by electrolytic copper cathode, we studied not only copper recycling technology which is being commercialized but also current research trend under the research stage. This study aims to examine the characteristics of each process and the areas where future recycling technology development is required.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.4
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• pp.105-111
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• 2023

Electronic devices have been evolved to be mechanically flexible that can be endured repetitive deformation. This evolution emphasizes the importance of long-term reliability in metal wiring connecting electronic components, especially under bending fatigue in compressed environments. This study investigated methods to enhance adhesion between copper (Cu) and polyimide (PI) substrates, aiming to improve the reliability of copper wiring under such conditions. We applied oxygen plasma treatment and introduced a chromium (Cr) adhesion layer to the polyimide substrate. Our findings revealed that these adhesion enhancement methods significantly affect compression fatigue behavior. Notably, the chromium adhesion layer, while showing weaker fatigue characteristics at 1.5% strain, demonstrated superior performance at 2.0% strain with no delamination, outperforming other methods. These results offer valuable insights for improving the reliability of flexible electronic devices, including reducing crack occurrence and enhancing fatigue resistance in their typical usage environments.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.84-84
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• 1999

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.164-164
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• 2013

전기수력학을 이용한 프린팅 기술은 마이크로 나노 크기의 프린팅에 효과적으로 응용되고 있으며, 전도성 입자의 인쇄를 통한 미세 전기 배선의 형성에도 사용되고 있다. 본 연구에서는 금속 고체 입자를 사용하지 않고, 금속 이온 기반의 용액을 제조하여 마이크로 크기의 패턴을 형성하였다.

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.723-733
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• 2016

Intensive researches have been focused on the 3-dimensional packaging technology using through silicon via (TSV) to overcome the limitation in Cu interconnection scaling. Void-free filling of TSV by the Cu electrodeposition is required for the fabrication of reliable electronic devices. It is generally known that sufficient inhibition on the top and the sidewall of TSV, accompanying the selective Cu deposition on the bottom, enables the void-free bottom-up filling. Organic additives contained in the electrolyte locally determine the deposition rate of Cu inside the TSV. Investigation on the additive chemistry is essential for understanding the filling mechanisms of TSV based on the effects of additives in the Cu electrodeposition process. In this review, we introduce various filling mechanisms suggested by analyzing the additives effect, research on the three-additive system containing new levelers synthesized to increase efficiency of the filling process, and methods to improve the filling performance by modifying the functional groups of the additives or deposition mode.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.95-99
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• 2008

Cu has been used for metallic interconnects in ULSI applications because of its lower resistivity according to the scaling down of semiconductor devices. The resistivity of Cu lines will affect the RC delay and will limit signal propagation in integrated circuits. We investigated the electrolyte effects of the electroplating solution in the resistivity value of Cu films grown by electroplating deposition (EPD). The resistivity was measured with a four-point probe and the material properties were investigated with XRD (X-ray Diffraction), AFM (Atomic Force Microscope), FE-SEM (Field Emission Scanning Electron Microscope) and XPS (X-ray Photoelectron Spectroscopy). From these experimental results, we found that the electrolyte condition plays an Important role in formation of Cu film with lower resistivity by EPD.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.1
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• pp.49-54
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• 2022

The copper plating process used to fabricate the submicron damascene pattern of Cu wiring for Si wafer was applied to the plating of a PCB pattern of several tens of microns in size using the same organic additives and current density conditions. In this case, the non-uniformity of the plating thickness inside the pattern was observed. In order to quantitatively analyze the cause, a numerical calculation considering the solution flow and electric field was carried out. The calculation confirmed that the depletion of Cu²⁺ ions in the solution occurred relatively earlier at the bottom corner than the upper part of the pattern due to the plating of the sidewall and the bottom at the corner of the pattern bottom. The diffusion coefficient of Cu²⁺ ions is 2.65 10^-10 m²/s, which means that Cu²⁺ ions move at 16.3 ㎛ per second on average. In the cases of small damascene patterns, the velocity of Cu²⁺ ions is high enough to supply sufficient ions to the inside of the patterns, while sufficient time is required to replenish the exhausted copper ions in the case of a PCB pattern having a size of several tens of microns. Therefore, it is found that the thickness uniformity can be improved by reducing the current density to supply sufficient copper ions to the target area.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.517-523
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• 2015

As the aluminum (Al) metallization process was replaced with copper (Cu), the damascene process was introduced, which required the planarization step to eliminate over-deposited Cu with Chemical Mechanical Polishing (CMP) process. In this study, the verification of the corrosion inhibitors, one of the Cu CMP slurry components, was conducted to find out the tendency regarding the carboxyl and amino functional group in neutral environment. Through the results of etch rate, removal rate, and chemical ability of corrosion inhibitors based on 1H-1,2,4-triazole as the base-corrosion inhibitor, while the amine functional group presents high Cu etching ability, carboxyl functional group shows lower Cu etching ability than base-corrosion inhibitor which means that it increases passivation effect by making strong passivation layer. It implies that the corrosion inhibitor with amine functional group was proper to apply for 1st Cu CMP slurry owing to the high etch rate and with carboxyl functional group was favorable for the 2nd Cu CMP slurry due to the high Cu removal rate/dissolution rate ratio.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1806-1809
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• 2008

Study that form micro pattern by direct ink jet printing method is getting attention recently. Direct ink jet printing spout fine droplet including nano metal particle by force or air pressure. There is reason which ink jet printing method is profitable especially in a various micro-patterning technology. It can embody patterns directly without complex process such as mask manufacture or screen-printing for existent lithography. In this study, research of a technology that ejects fine droplet form of Pico liter and forms metal micro pattern was carried with inkjet head of piezoelectricity drive system. Droplet established pattern while ejecting consecutively and move on the surface at the fixed speed. Patterns formed in ink are mixed with organic solvent and polymer that act as binder. So added thermal hardening process after evaporate organic solvent at isothermal after printing. I executed high frequency special quality estimation of CPW transmission line to confirm electrical property of manufactured circuit board. We tried a large area printing to confirm application possibility of an ink jet technology.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.4
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• pp.69-74
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• 2010

A new package substrate for dynamic random access memory(DRAM) devices has been developed using selective aluminum anodization. Unlike the conventional substrate structure commonly made by laminating epoxy-based core and copper clad, this substrate consists of bottom aluminum, middle anodic aluminum oxide and top copper. Anodization process on the aluminum substrate provides thick aluminum oxide used as a dielectric layer in the package substrate. Placing copper traces on the anodic aluminum oxide layer, the resulting two-layer metal structure is completed in the package substrate. Selective anodization process makes it possible to construct a fully filled via structure. Also, putting vias directly in the bonding pads and the ball pads in the substrate design, via in pad structure is applied in this work. These arrangement of via in pad and two-layer metal structure make routing easier and thus provide more design flexibility. In a substrate design, all signal lines are routed based on the transmission line scheme of finite-width coplanar waveguide or microstrip with a characteristic impedance of about $50{\Omega}$ for better signal transmission. The property and performance of anodic alumina based package substrate such as layer structure, design method, fabrication process and measurement characteristics are investigated in detail.