• 한국표면공학회지
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• 제36권5호
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• pp.393-397
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• 2003

The effects of the composition and additives on the blackening and deposition rate of electroless Ni-Zn plating have been examined. Hydrazine resulted in lower sheet resistance of the deposit than sodium hypophosphite. Zinc concentration more than 15 wt% and small amount of ammonium sulfate in the deposits were needed in obtaining Ni-Zn deposit with a black color. An optimum condition was obtained for the black Ni-Zn deposit at an appreciable deposition rate.

• 한국표면공학회지
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• 제33권4호
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• pp.273-280
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• 2000

Silver was deposited on glass by electroless plating and electroplating. Surface properties were investigated using the AFM. Crystal structure of deposit layers was confirmed by TEM and XRD. Electroplating is performed by DC plating and pulse plating, respectively. This study resulted in followings, first, deposit of electroless plating showed fine grain and was similar to the amorphous structure. Second, electrodeposit on the electroless layer was revealed following results ; (1) more uniform layer and finer grains were obtained with increasing frequency (2) more isotropic structure was obtained with increasing frequency (3) finer grains at 25% duty cycle was obtained (4) grain size and roughness of the silver deposit was decreased with increasing frequency.

• 전기화학회지
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• 제3권4호
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• pp.196-199
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• 2000

무전해 도금은 내식성, 내구성, 전도성 특별히 비전도성 물질의 도금이 요구되는 모든 재료에 폭 넓게 사용되는 우수한 표면 처리 방법이다. 무전해 니켈 도금은 비자성, 무정형 구조,내구성, 내식성 그리고 열정 안정성 등의 많은 장점을 갖는다. 본 연구에서는 무전해 니켈 도금의 열처리에 따른 무전해 니켈-인 도금의 경도와 내식성의 변화를 연구하였다. 가장 높은 경도 값은 $500^{\circ}C$열처리에서 얻어졌다. $300^{\circ}C$에서 열처리한 도금의 내식성이 60시간 동안 1몰의 황산 수용액에서 테스트 한 결과 가장 우수하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.625-628
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• 1999

Recently. high-density printed circuit boards(PCB) become indispensable with the minaturization of components. Nickel is deposited on the copper patterns and followed by the gold deposition for improving connection reliability between the printed circuit boards and electronic components. Conventionally electrodeposition has been applied to metalization of copper patterns. However metalization by this method is not applicable for the isolated fine and concentrated patterns. Therefore, metalization technology of the fine patterns by electroless plating is required in place of electrodeposition. The application of electroless nickel plating for interconnection with solder strongly relies on the solderability and the interactions between nickel and solder. Factors such as phosphorus content of the deposit additive and bath temperature may influence solderability of the electroless nickel deposit. So solderability of electroless nickel/ gold deposits was investigated with substrates plated changing the condition of nickel solution.

• 한국표면공학회지
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• 제24권4호
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• pp.187-195
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• 1991

Adhesion strength of electroless-plated Ni, Ni-P and Cu deposites on alumina substrate has been studied. Grain boundary spaces produced on the substrate surface by etching treatment provided anchoring sites for enhancing the adhesion strength. Adhesion strengths of Ni-P and Ni deposit were higher than that of Cu deposit, because of higher initial nucleation rates than the latter. The electroless-plated Ni-P and Ni underlayer improved the adhesion strength of the Cu deposit. In could be attributed to the enhanced adhesion between the substrate and those underlayers as well as the satisfactory adhesion between Cu deposits and those underlayers. Heat treatment was also conducted in order to enhance the adhesion strength of Cu layer. The strength was enhanced by about 19% when the treatment was conducted at $150^{\circ}C$ for 2 hours. The enhancement was attributed to relief of internal stress and release of hydrogen.

• 한국표면공학회지
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• 제37권6호
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• pp.326-334
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• 2004

Deposit charateristics of Electroless nickel(EN) were investigated with various complexing agents. As expected, the deposition rate of nickel is increased with pH and that of Phosphorous is decreased with pH. The result of SEM investigation shows that the rough surface crystallization is appeared with pH. It is show that the surface resistance of EN deposit is decreased with pH at 85$^{\circ}C$.

• 한국재료학회지
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• 제13권2호
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• pp.101-105
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• 2003

In this study, we have investigated the availability of the electroless Ni-B plating for a diffusion barrier of the bus electrode. The Ni-B layer of 1$\beta$: thick was electroless deposited on the electroplated Cu bus electrode for AC plasma display. The layer was to encapsulate Cu bus electrode to prevent from its oxidation and to serve as a diffusion barrier against Cu contamination of the transparent dielectric layer in AC plasma display. The microstructure of the as-plated barrier layer was made of an amorphous phase and the structure was converted to crystalline at about 30$0^{\circ}C$. The concentration of boron was about 5∼6 wt.% in the electroless Ni-B deposit regardless of DMAB concentration. The electroless Ni-B deposit was coated on the surface of the electroplated Cu bus electrode uniformly. And the electroless Ni-B plating was found to be an appropriate process to form the diffusion barrier.

• 대한금속재료학회지
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• 제46권11호
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• pp.725-729
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• 2008

Deposition characteristics of electroless plated Ni-W-P films were investigated for various complexing agents. Used complexing agents are sodium citrate, sodium gluconate and sodium malonate. In this study, the existing mixed potential theory could explain the overall mechanism of Ni-W-P electroless plating for all complexing agents. The deposition rate could be also expected by the theory. The deposited Ni-W-P films were evaluated in term of surface hardness and corrosion resistance. Microhardness of the deposit increased about 1,000 Hv after heat treatment for one hour at $400^{\circ}C$, because it was above the crystallization temperature of $Ni_3P$. The deposited Ni-W-P films can exhibit excellent corrosion resistance in using sodium malonate as a complexing agent, the other hand the using sodium gluconate was the worst corrosion resistance. The worst corrosion resistance was due to a large number of nano-sized pin-holes or small pores. The plating current at the mixed potential increases when the using sodium malonate as a complexing agent, it was explained by the cross section.

• Journal of Welding and Joining
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• 제32권3호
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• pp.60-67
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• 2014

The ability of electronic packages and assemblies to resist solder joint failure is becoming a growing concern. This paper reports on a study of high speed shear energy of Sn-4.0wt%Ag-0.5wt%Cu (SAC405) solder with different electroless Ni-P thickness, with $HNO_3$ vapor's status, and with various pre-conditions. A high speed shear testing of solder joints was conducted to find a relationship between the thickness of Ni-P deposit and the brittle fracture in electroless Ni-P deposit/SAC405 solder interconnection. A focused ion beam (FIB) was used to polish the cross sections to reveal details of the microstructure of the fractured pad surface with and without $HNO_3$ vapor treatment. A scanning electron microscopy (SEM) and an energy dispersive x-ray analysis (EDS) confirmed that there were three intermetallic compound (IMC) layers at the SAC405 solder joint interface: $(Ni,Cu)_3Sn_4$ layer, $(Ni,Cu)_2SnP$ layer, and $(Ni,Sn)_3P$ layer. The high speed shear energy of SAC405 solder joint with $3{\mu}m$ Ni-P deposit was found to be lower in pre-condition level#2, compared to that of $6{\mu}m$ Ni-P deposit. Results of focused ion beam and energy dispersive x-ray analysis of the fractured pad surfaces support the suggestion that the brittle fracture of $3{\mu}m$ Ni-P deposit is the result of Ni corrosion in the pre-condition level#2 and the $HNO_3$ vapor treatment.

• 동력기계공학회지
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• 제8권3호
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• pp.36-43
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• 2004

The effect of bath composition, plating condition and plating rate on the magnetic property of electroless Co-Cu-P deposits were investigated. With increasing $CuCl_2$ concentration in the bath, plating rate increased, while the Br value of deposit decreased sharply. Deposited surface were inferiority by the increase pH above 10.5, bath temperature higher than $80^{\circ}C$. Plating reaction had been ceased by the increase of pH above 11, bath temperature higher than $90^{\circ}C$ and under $40^{\circ}C$. The Br value of deposit was uniform with various concentration of complexing agent(sodium citrate) in the bath. The Br value of deposit was almost equal to that found by the addition of stabilizer (thiourea) and accelerator(NaF). The Br value of deposit was uniform in plating time(20min) and heat treatment temperature(below $200^{\circ}C$), and were confirmed to have adequate bath stability for practical use.