• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2011.05a
• /
• pp.113-113
• /
• 2011

알루미늄 박막 커패시터 제작을 위해 선택적인 알루미늄 etching과 anodizing을 이용한 유전체($Al_2O_3$) 형성, 전극층 형성을 위한 무전해 Ni-P 도금을 진행하였다. $5{\mu}m$ patterns/$10{\mu}m$ space를 가지는 dot patterns을 알루미늄 기판에 patterning하고, 이를 각각의 전류밀도 조건에서 etching한 후, barrier type anodizing을 진행하였다. 유전체에 전극층은 무전해 Ni-P 도금을 통해 형성하였으며, 이렇게 제작된 알루미늄 박막 커패시터 특성을 평가하였다.

• Korean Journal of Materials Research
• /
• v.16 no.7
• /
• pp.430-434
• /
• 2006

Au/Ni coatings are widely used in the electrical interconnect system, such as connectors, sockets and wire crimps. But due to repeated mechanical contacts, fretting corrosion occurs and causes a rapid increase in resistance. As an attempt to resolve these problem, application of Ni-P-PTFE to replace Ni undercoats was proposed, for which basic materials properties of Ni-P-PTFE coatings for preventing fretting corrosion was examined in this study. The Ni-P-PTFE coatings were formed by electroless Ni plating and PTFE coating followed by the heat-treatment. PTFE particles were found to be uniformly distributed in the Ni-P matrix. The Ni-P-PTFE coatings showed the excellent anti-adherent property with the contact angle of $104.3^{\circ}$, microhardness of 144.3 Hv comparable to that of Ni-P, and electric conductivity equivalent to that of Ni-P.

• Proceedings of the KAIS Fall Conference
• /
• 2002.11a
• /
• pp.243-245
• /
• 2002

ABS(Acrylonitrile Butadiene Styrene) 수지는 낮은 비중과 전기전도도, 가공성 등 우수한 물리적 성질을 갖는다. ABS 수지 제조방법인 Conventional process와 이를 개선한 MmSH(Momentary mold Surface Heating) injection process로 제조하여 나타나는 도금의 최적 조건을 연구하였다. 탈지, 에칭, Neutralization, Catalyzing, Accelerating의 전처리 과정을 거쳐 pH 변화에 따른 무전해 Ni 도금을 실시한 결과 각 수지 모두 pH7 이상에서 도금속도와 밀착력이 증가하였으나 MmSH injection process로 제작된 ABS 수지보다 Coventional process에서 제작된 ABS 수지의 밀착력이 우수한 경향이 나타났다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.6
• /
• pp.481-486
• /
• 2010

ENIG (electroless Ni immersion gold) is one of surface finishing which has been most widely used in fine pitch SMT (surface mount technology) and BGA (ball grid array) packaging process. The reliability for package bondability is mainly affected by interfacial reaction between solder and surface finishing. Since the behavior of IMC (intermetallic compound), or the interfacial reaction between Ni and solder, affects to some product reliabilities such as solderability and bondability, understanding behavior of IMC should be important issue. Thus, we studied the properties of ENIG with P contents (9 wt% and 13 wt%), where the P contents is one of main factors in formation of IMC layer. The effect of P content was discussed using the results obtained from FE-SEM(field-emission scanning electron microscope), EPMA(electron probe micro analyzer), EDS(energy dispersive spectroscopy) and Dual-FIB(focused ion beam). Especially, we observed needle type irregular IMC layer with decreasing Ni contents under high P contents (13 wt%). Also, we found how IMC layer affects to bondability with forming continuous Kirkendall voids and thick P-rich layer.

• Journal of Powder Materials
• /
• v.24 no.3
• /
• pp.242-247
• /
• 2017

In this study, the electroless nickel plating method has been investigated for the coating of Ni nanoparticles onto fine Al powder as promising energetic materials. The adsorption of nickel nanoparticles onto the surface of Al powders has been studied by varying various process parameters, namely, the amounts of reducing agent, complexing agent, and pH-controller. The size of nickel nanoparticles synthesized in the process has been optimized to approximately 200 nm and they have been adsorbed on the Al powder. TGA results clearly show that the temperature at which oxidation of Al mainly occurs is lowered as the amount of Ni nanoparticles on the Al surface increases. Furthermore, the Ni-plated Al powders prepared for all conditions show improved exothermic reaction due to the self-propagating high-temperature synthesis (SHS) between Ni and Al. Therefore, Al powders fully coated by Ni nanoparticles show the highest exothermic reactivity: this demonstrates the efficiency of Ni coating in improving the energetic properties of Al powders.

• Particle and aerosol research
• /
• v.10 no.4
• /
• pp.177-182
• /
• 2014

In this study, nickel-coated aluminum (Ni/Al) powders were synthesized for the utilization of energetic applications. Oxide materials present at the surface of Al powders of $45{\mu}m$ in averaged size were removed by using sodium hydroxide(NaOH) solution which is used for controlling pH. Nickel material is coated into the surface of oxide-removed Al powders by electroless-plating process. The microstructure of fabricated Ni/Al powders shows that nickel layers with a few hundreds nm were very homogeneously formed onto the surface of Al powders. The oxidation behavior of Ni/Al exihibit somewhat faster oxidation rate than that of pure Al with surface oxidation. Also, the higher exothermic reaction was observed from the Ni/Al powders. From the result of this, nickel coating is very promising method to obtain highly reactive and safe Al powders for energetic applications.

• Journal of the Microelectronics and Packaging Society
• /
• v.30 no.1
• /
• pp.49-54
• /
• 2023

Recently, System in Packaging(SIP) technology needs to meet high frequency (5G and more) communication technology and fine pitch surface treatment. The conventional Electroless Ni/Immersion Au plating(ENIG) is not suitable for high frequency range because of magnetic properties are increasing the transmission loss. Without nickel plating layer, the pattern and pad reliability level must be meet the condition. In this review paper, we investigated research trends on Ni-less surface treatment technology for high-frequency communication and frequency characteristics according to materials.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2002.05a
• /
• pp.85-91
• /
• 2002

Even though electroless Hi and Sn-Ag-Cu solder are widely used materials in electronic packaging applications, interfacial reactions of the ternary Ni-Cu~Sn system have not been known well because of their complexity. Because the growth of intermetallics at the interface affects reliability of solder joint, the intermetallics in Ni-Cu-Sn system should be identified, and their growth should be investigated. Therefore, in present study, interfacial reactions between electroless Ni UB7f and 95.5Sn-4.0Ag-0.5Cu alloy were investigated focusing on morphology of the IMCs, thermodynamics, and growth kinetics. The IMCs that appear during a reflow and an aging are different each other. In early stage of a reflow, ternary IMC whose composition is Ni$_{22}$Cu$_{29}$Sn$_{49}$ forms firstly. Due to the lack of Cu diffusion, Ni$_{34}$Cu$_{6}$Sn$_{60}$ phase begins growing in a further reflow. Finally, the Ni$_{22}$Cu$_{29}$Sn$_{49}$ IMC grows abnormally and spalls into the molten solder. The transition of the IMCs from Ni$_{22}$Cu$_{29}$Sn$_{49}$ to Ni$_{34}$Cu$_{6}$Sn$_{60}$ was observed at a specific temperature. From the measurement of activation energy of each IMC, growth kinetics was discussed. In contrast to the reflow, three kinds of IMCs (Ni$_{22}$Cu$_{29}$Sn$_{49}$, Ni$_{20}$Cu$_{28}$Au$_{5}$, and Ni$_{34}$Cu$_{6}$Sn$_{60}$) were observed in order during an aging. All of the IMCs were well attached on UBM. Au in the quaternary IMC, which originates from immersion Au plating, prevents abnormal growth and separation of the IMC. Growth of each IMC is very dependent to the aging temperature because of its high activation energy. Besides the IMCs at the interface, plate-like Ag3Sn IMC grows as solder bump size inside solder bump. The abnormally grown Ni$_{22}$Cu$_{29}$Sn$_{49}$ and Ag$_3$Sn IMCs can be origins of brittle failure.failure.

• Korean Journal of Materials Research
• /
• v.5 no.8
• /
• pp.1013-1019
• /
• 1995

The thin plate of Co-Ni-P was deposited on the polyester film by the electroless plating method. Through present experiments, deposition rates and metal compositions of the plates were determined according to compositions of solution, pH and temperature. Also, magnetic properties of plates were examined according to metal compositions. Considering magnetic properties and deposition rates of electroless plating, the best condition was obtained as pH of 8.5 and 90℃. It was observed that metal compositions were evidently varied by the pH of solutions and the concentration of complex agents. However. they were not affected by other factors. At the optimum condition, the composition of the plate was Co(78%), Ni(16%), and P(6%). Also, it was found that the coercive force was 370 Oe, and squareness was 0.65 at this condition. Magnetic properties (hard or soft) of thin plates were determined by metal compositions. Therefore. the plate became soft magnetic plate as the composition of nickel increased over 30 per cents. The crystal structure of the soft magnetic plate was found to be amorphous in which it was strongly oriented to the (111)phahe of nickel. On the ohter hand, the hard magnetic place was found to be hcp crystalline of α-cobalt which was oriented to the (101)phase of cobalt and the (100)phase of cobalt.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2004.11a
• /
• pp.59-59
• /
• 2004