• 한국재료학회지
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• 제9권9호
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• pp.926-931
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• 1999

Sn-3.5g 무연합금을 Cu 및 Alloy42 리드프레임에 납땜접합 (solder joint)하고 미세조직, 젖음성, 전단강도, 시효 효과를 측정하여 비교하였다. Cu의 경우, 땜납의 Sn기지상안에 Ag(sub)3Sn과 Cu(sub)6Sn(sub)5상이, 그리고 땜납/리드프레임의 경계면에는 $1~2\mu\textrm{m}$ 두께의 Cu(sub)6Sn(sub)5 상이 형성되었다. Alloy42의 경우, 기지상내에 낮은 밀도의 $Ag_3Sn$상만이, 그리고 계면에는 $0.5~1.5\mu\textrm{m}$ 두께의 $FeSn_2$이 형성되었다. 한편, Cu에 비해 Alloy42 리드프레임에서 퍼짐면적은 크고 접촉각은 작아 더 우수한 젖음성을 나타내었으나, 전단강도는 35%, 연산율은 75%로 낮았다. $180^{\circ}C$에서 1주일간 시효처리 후, Cu 리드프레임에는 계면 $\eta-Cu_6Sn_5$ 층외에 $\xi-Cu_3Sn$층이 성장하였고, Alloy42 리드프레임에는 기지상내에 $Ag_3Sn$이 구형으로 조대하게 성장하였고, 계면에는$FeSn_2$층만이 약 $1.5\mu\textrm{m}$로 성장하였다.

• 한국표면공학회지
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• 제39권6호
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• pp.276-281
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• 2006

In order to improve the performance of PPFs (Pre-Plated Frames), a PPF that employed a Cu-Sn alloy instead of conventionally used Ni was developed and then its properties were investigated. It was found that the electoplated Cu-Sn alloy layer was a mixture of uniformly distributed fine crystallites, resulting In better wettability and crack resistance than those of Ni PPF. Moreover, as in Cu/Ni/Pd/Au PPF, migration of copper atoms from the base metal to the top of the Cu/Cu-Sn/Pd/Au PPF surface was not found although the Cu-Sn layer itself contained considerable amount of copper. It was expected that, by using the newly developed Cu-Sn PPF, any possible heat generation and signal interrupt caused by an external electro-magnetic field could be reduced because the Cu-Sn layer was paramagnetic, i.e., nonmagnetic.

• 한국재료학회지
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• 제12권3호
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• pp.225-230
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• 2002

Sn was selected as an alloying element of Cu. The Cu-Sn thin layers were deposited on the Si substrates by the electroplating method and their properties were studied. By rapidly thermal annealing(RTA) up to 40$0^{\circ}C$ after electroplating, sheet resistance decreased and adhesion strength increased, but that trend was reversed at the 50$0^{\circ}C$ RTA. Cu-Sn particles grew dense and the surface was uniform up to 40$0^{\circ}C$, but at 50$0^{\circ}C$, empty area was introduced and the surface became rough owing to oxidation and particle coarsening and agglomeration. Deposited layer contained significant amount of Si, while pure Cu-Sn layer with the composition ratio of 90:10 was present only on the top surface. However, no significant change in the Cu composition within alloy layers occured by the RTA regardless of its temperature. This indicates that the Cu diffusion into the Si was suppressed by the presence of Sn.

• 한국재료학회지
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• 제13권2호
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• pp.133-136
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• 2003

Sn-2.5Cu alloy layers were deposited on the Alloy 42 lead-frame substrates by the electroplating method, and their microstructures, adhesion strength, and electrical resistivity were measured to evaluate the applicability of Sn-Cu alloy as a surface finishing material of electronic parts. The Sn-2.5Cu layers were electroplated in the granular form, and composed of pure Sn and Cu$_{6}$Sn$_{5}$ intermetallic compound. Surfaces of the electroplated Sn-2.5Cu layers were rather rough and also the thickness variance was large. The adhesion strength of the Sn-2.5Cu electroplated layers was highly comparable to that of the electroplated Cu alloy layer and the electrical conductivity was about 10 times higher than the pure Sn. After the 20$0^{\circ}C$ 30 min. annealing of the electroplated Sn-2.5Cu layers, the surface roughness was reduced, and adhesion strength and conductivity were improved. These results showed the Sn-Cu alloys can be used as an excellent surface finishing material.ial.

• 한국전기전자재료학회논문지
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• 제32권2호
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• pp.134-140
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• 2019

Oxide ($SnO_2$)/metal alloy (Cu(Ni))/oxide ($SnO_2$) multilayer films were fabricated using the magnetron sputtering technique. The oxide and metal alloy were $SnO_2$ and Ni-doped Cu, respectively. The structural, optical, and electrical properties of the multilayer films were investigated using X-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectrophotometry, and 4-point probe measurements, respectively. The properties of the $SnO_2/Cu(Ni)/SnO_2$ multilayer films were dependent on the thickness and Ni doping of the mid-layer film. Since Ni atoms inhibit the diffusion and aggregation of Cu atoms, the grain growth of Cu is delayed upon Ni addition. For $250^{\circ}C$, the Haccke's figure of merit (FOM) of the $SnO_2$ (30 nm)/Cu(Ni) (8 nm)/$SnO_2$ (30 nm) multilayer film was evaluated to be $0.17{\times}10^{-3}{\Omega}^{-1}$.

• 소성∙가공
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• 제7권5호
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• pp.481-488
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• 1998

The active metal brazing was applied to bond Alumina and Ni-Cr steel by Ag-Cu-Zr-Sn alloy and the interfacial microstructure and reaction mechanism were investigated. Polycrystalline monoclinic $ZrO_2$ with a very fine grain of 100-150 nm formed at the alumina grain boundary contacted with Zr segregation layer at the interface. The $ZrO_2$ layer containing the inclusions and cracks were developed at the boundary of inclusion/$ZrO_2$ due to the difference in specific volume. The development of $ZrO_2$ at the interface was successfully explained by the preferential penetration of $ZrO_2$ at the interface was successfully explained by the preferential penetration of Zr atoms a higher concentration of oxygen and a high diffusion rate of Al ions into molten brazing alloy.

• 한국표면공학회지
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• 제4권1호
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• pp.16-23
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• 1971

In this study , fluoborte solution consisting of lead fluoborate, tin fluoborate and cupric acetate was used. By addition of small amount of Cu+= ion to the solution, the Cu content of deposition layer was almost controlled less than 5%. The amount of Cu in deposition layer was almost constant without any influence of Pb++ & Sn++ in the solution, and the amount of Pb was increased by the increase of total concentration of Pb++ +Sn++ in the solution, and the amount of Pb was increased by the increase of total concentration of Pb++ +Sn++ in the solution . Agitation of plating solution & low current density result in the increase of Cu content. Analyzing of microscopic structures and etching tests of the deposited alloy, it was believed that the alloy had a lamellar structure consisting of copper rich lamellar and lead rich layer.

• Applied Science and Convergence Technology
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• 제23권6호
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• pp.345-350
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• 2014

The surface oxidation mechanism of lead-free solder alloys has been investigated with multiple reflow using X-ray photoelectron spectroscopy. It was found that the solder surface of Sn-Ag-Cu-In solder alloy is surrounded by a thin $InO_x$ layer after reflow process; this coating protects the metallic surface from thermal oxidation. Based on this result, we have performed a wetting balance test at various temperatures. The Sn-Ag-Cu-In solder alloy shows characteristics of both thermal oxidation and wetting balance better than those of Sn-Ag-Cu solder alloy. Therefore, Sn-Ag-Cu-In solder alloy is a good candidate to solve the two problems of easy oxidation and low wettability, which are the most critical problems of Pb-free solders.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.640-644
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• 2000

Sn-3.5Ag 무연합금을 Cu 및 Alloy42 리드프레임에 납땜접합(solder joint)하고 미세조직, 젖 음성, 전단강도, 시효효과를 측정하여 비교하였다. CU의 경우, 납땜의 Sn기지상안에 Ag$_3$Sn$_{5}$상이, 그리고 땜납/리드프레임의 경계면에는 1~2$\mu\textrm{m}$ 두께의 Cu$_{6}$Sn$_{5}$상이 형성되었다. Alloy42의 경우, 기지상내에는 낮은 밀도의 Ag$_3$Sn상만이, 그리고 계면에는 0.5~1.5$\mu\textrm{m}$ 두께의 FeSn$_2$이 형성되었다. 한편. Cu에 비해 Alloy42 리드프레임에서 전단강도는 낮았으며, 시효 시간에 따라 전단강도는 모두 감소하였다. 18$0^{\circ}C$에서 1주일간 시효처리 후, Cu 리드프레임에는 계면에 η-Cu$_{6}$Sn$_{5}$ 층이 15-20$\mu\textrm{m}$ 성장하였고, A11oy42 리드프레임에는 기지상내에 AgSn$_3$이 조대하게 성장하였으며, 계면에는 FeSn$_2$층만이 약 $1.5\mu\textrm{m}$로 성장하였다.성장하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.235-237
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• 2007

In this paper, fabrication of Sn-3.0Ag-0.5Cu solder bumping having accurate composition and behavior of intermetallic compounds(IMCs) growth at interface between Sn-Ag-Cu bumps and Cu substrate were studied. The ternary alloy of the Sn-3.0Ag-0.5Cu solder was made by two binary(Sn-Cu, Sn-Ag) electroplating on Cu pad. For the manufacturing of the micro-bumps, photo-lithography and reflow process were carried out. After reflow process, the micro-bumps were aged at $150^{\circ}C$ during 1 hr to 500 hrs to observe behavior of IMCs growth at interface. As a different of Cu contents(0.5 or 2wt%) at Sn-Cu layer, behavior of IMCs was estimated. The interface were observed by FE-SEM and TEM for estimating of their each IMCs volume ratio and crystallographic-structure, respectively. From the results, it was found that the thickness of $Cu_3Sn$ layer formed at Sn-2.0Cu was thinner than the thickness of that layer be formed Sn-0.5Cu. After aging treatment $Cu_3Sn$ was formed at Sn-0.5Cu layer far thinner.