• Journal of the Korean institute of surface engineering
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• v.49 no.5
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• pp.401-407
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• 2016

In this work, effect of zincate treatment of AZ91 Mg alloy on the following electrodeposition of copper was examined in a non-cyanide bath containing pyrophosphate ions in view of surface morphology and adhesion of the electrodeposited copper layer. Without zincate treatment, the electrodeposited copper layer showed very porous structure and poor adhesion. On the other hand, the copper layer electrodeposited on the zincate-treated surface showed dense structure and good adhesion. The dissolution rate of AZ91 Mg alloy after the zincate treatment appeared to decrease about 40 times in the copper pyrophosphate bath, as compared to that of the surface without zincate treatment. The porous morphology and poor adhesion of a copper layer on the AZ91 Mg alloy surface without zincate treatment were attributed to small number of nucleation sites of copper because of rapid dissolution of the magnesium substrate in the pyrophosphate bath. Based on the experimental results, it is concluded that the zincate treatment to form a conducting and protecting layer on the AZ91 Mg alloy surface is essential for successful electrodeposition of a copper layer on AZ91 Mg alloy with good adhesion and dense structure in the copper pyrophosphate bath.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.194.1-194.1
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• 2016

The present study investigated the effect of zincate treatment time on the dissolution behavior and the deposition of copper by immersion process and electroplating process on AZ31 Mg alloy substrate in a copper pyrophosphate bath. Without zincate pretreatment, the AZ31 Mg substrate quickly dissolved in the copper pyrophosphate solution although an external cathodic current was applied. The copper layers deposited on non-zincate treated AZ31 Mg alloy substrate by both immersion and electroplating processes showed very porous structure and very poor adhesion. With increasing zincate treatment time up to 2 min, the dissolution of AZ31 substrate in pyrophosphate solution rapidly decreased and the deposited copper layer was less porous and exhibited stronger adhesion. The immersion of AZ31 Mg sample in zincate solution for 5 min was found as a critical time for producing a non-porous and adherent electrodeposited copper layer on AZ31 Mg alloy. The optimum zincating time can be determined by observing the open circuit potential (OCP) of AZ31 Mg alloy samples in a copper pyrophosphate electroplating bath. The OCP reached a stable value of about -0.10 V (vs. SCE) after 5 min of immersion in the copper pyrophosphate electroplating solution.

• Journal of the Korean institute of surface engineering
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• v.44 no.6
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• pp.239-245
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• 2011

Magnesium alloys is the lightest by structural metals, but it is not good corrosion resistant because of pit, void. Particularly, AZ31B magnesium alloy sheets that have slag, scratch by rolling process indicate some defects. The objective of this research is to perform uniform plating on AZ31B by studying etching and zincate process. Especially, zincate treatment by zinc salt and pyrophosphate is the most important in the decoration plating. Dissolution of magnesium is reduced by the formation of uniform zinc conversion layer during strick and post process, which decreases defects for plating process.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.166.2-166.2
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• 2016

알루미늄 합금 표면의 도금피막 밀착성을 향상시키는 전처리 방법으로는 아연 치환법[이하; 징케이트(Zincate)처리]이 사용되고 있다. 2중 징케이트 처리에 의해 아연 치환층이 치밀화 하여, 아연 치환층의 일부가 알루미늄과 합금화 한다. 일본에서는 2중 징케이트 처리의 각 과정에 있어서 알루미늄 합금의 표면 상태를 X선 광전자분광장치(XPS)로 조사하였다. 본고에서는 Fe합금 징케이트 처리의 각 공정에 있어서 알루미늄 합금 표면을 XPS로 조사한 결과, 징케이트 처리에 기초한 피막의 구조와 밀착성 개선효과에 관하여 기술하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.100-100
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• 2015

본 연구에서는 AZ31 마그네슘 합금의 징케이트 피막 형성 메커니즘을 용액의 조성에 따라 연구하였고, 징케이팅 공정에서 초음파가 피막의 형성 미 성장에 미치는 영향에 살펴보았다. 또한 AZ31 마그네슘 합금을 징케이트 처리한 후 구리를 도금하여 피막 형성 특성을 살펴보았다.

• Korean Journal of Materials Research
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• v.9 no.11
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• pp.1095-1101
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• 1999

Electroless Ni plating is applied to form bumps and UBM layer for flip chip interconnection. Characteristics of electroless Ni are also investigated. Zincate pretreatment is analyzed and plated layer characteristics are investigated according to variables like temperature, pH and heat treatment. Based on these observations, characteristics dependence to each variables and optimum electroless Ni plating conditions for flip-chip interconnection are suggested. Electroless Ni has 10wt% P, $60\mu\Omega$-cm resistivity, 500HV hardness and amorphous structure. It changes crystallized structure and hardness increases after heat treatment After interconnection of electroless Ni bumps by ACF flip chip method, we show their advantages and possibility in microelectronic package applications.

• Korean Journal of Materials Research
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• v.6 no.7
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• pp.700-708
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• 1996

Electroless plating technique was utilized to flip chip bonding to improve surface mount characteristics. Each step of plating procedure was studied in terms pf pH, plating temperature and plating time. Al patterned 4 inch Si wafers were used as substrstes and zincate was used as an activation solution. Heat treatment was carried out for all the specimens in the temperature range from room temperature to $400^{\circ}C$ for $30^{\circ}C$ minutes in a vacuum furnace. Homogeneous distribution of Zn particles of size was obtained by the zincate treatment with pH 13 ~ 13.5, solution concentration of 15 ~ 25% at room temperature. The plating rates for both Ni-P and Au electroless plating steps increased with increasing the plating temperature and pH. The main crystallization planes of the plated Au were found to be (111) a pH 7 and (200) and (111) at pH 9 independent of the annealing temperature.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.456-462
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• 2002

In the present work, a low cost and fine pitch bumping process by electroless Ni/immersion Au UBM (under bump metallurgy) and stencil printing for the solder bump on the Al pad is discussed. The Chip used this experimental had an array of pad 14x14 and zincate catalyst treatment is applied as the pretreatment of Al bond pad, it was shown that the second zincating process produced a dense continuous zincating layer compared to first zincating. Ni UBM was analyzed using Scanning electron microscopy, Energy dispersive x-ray, Atomic force microscopy, and X-ray diffractometer. The electroless Ni-P had amorphous structures in as-plated condition. and crystallized at 321 C to Ni and Ni$_3$P. Solder bumps are formed on without bridge or missing bump by stencil print solder bump process.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.11a
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• pp.77-78
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• 2007

AZ31 마그네슘 판재의 장식 도금을 공정 개발을 적용하기 위한 기초 연구로서 전처리 특성에 따른 마그네슘 AZ31 판재의 아연치환도금의 특성을 연구하였다. AZ31 판재는 다이캐스팅으로 사용되는 AZ91 소재에 비해 산세에 대해 민감한 반응을 나타내었다. 소재의 균일화는 시편 E와 F에서 균일하고 광택 있는 표면을 얻었고, 질산은 표면 에칭효과만을 가진다는 것을 알 수 있었다. 아연치환도금을 위한 전처리에 있어서는 시편 E에서 우수한 밀착력을 나타내었다. 이후 청화동 도금과 황산동 도금, 니켈도금 3가 크롬도금을 실시하여, X-cutting 테이핑 테스트에서 양호한 밀착성과 내식성 72시간, 열탕시험을 만족하였다.