• 한국분말재료학회지
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• 제19권4호
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• pp.317-321
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• 2012

In this study, Cu-5Ni-10Sn(wt%) spinodal alloy was manufactured by gas atomization spray forming, and the microstructural features and mechanical properties of Cu-5Ni-10Sn alloy have been investigated during homogenization, cold working and age-hardening. The spray formed Cu-5Ni-10Sn alloy consisted of an equiaxed microstructure with a mixture of solid solution ${\alpha}$-(CuNiSn) grains and lamellar-structure grains. Homogenization at $800^{\circ}C$ and subsequent rapid quenching formed a uniform solid solution ${\alpha}$-(CuNiSn) phase. Direct aging at $350^{\circ}C$ from the homogenized Cu-5Ni-10Sn alloy promoted the precipitation of finely distributed ${\gamma}$' or ${\gamma}-(Cu,Ni)_3Sn$ phase throughout the matrix, resulting in a significant increase in microhardness and tensile strength. Cold working prior to aging was effective in strengthening Cu-5Ni-10Sn alloy, which gave rise to a maximum tensile strength of 1165 MPa. Subsequent aging treatment slightly reduced the tensile strength to 1000-1100 MPa due to annealing effects.

• 한국재료학회지
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• 제9권7호
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• pp.747-752
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• 1999

Sn-3.5Ag, Sn-3.5Ag-lZn Eoa납과 Cu기판과의 계면반응 및 접합특성에 관하여 검토하였다. Eoa납과 Cu기판이 접합된 시편은 $100^{\circ}C$와 $160^{\circ}C$에서 60일간 열처리하였으며, 전단하중을 가하여 강도를 측정하였다. $150^{\circ}C$에서 열처리에 따른 계면반응층의 두게는 Sn-3.5Ag/Cu계면이 Sn-3.5A9-IZn/Cu계면보다 빠르게 성장하였으며, 반응생성물 성장은$ t_{1/2}$에 비례하여 체적 확산 경향을 나타냈다. 계면 반응생성물은 Sn-3.5Ag/Cu계면의 경우 $Cu_{6}Sn_{5}$상이 형성되었고, $Ag_3Sn$상은 반응층 내부 및 반응층과 땜납의 계면에 석출하였으며, Zn을 첨가한 경우에는 계면에 $Cu_{6}Sn_{5}$ 상과 함께 $Cu_{5}Zn_{8}$상이 형성되었다. 땜납/기판의 전단강도는 Sn-3.5Ag합금에 Zn을 1% 첨가하면 증가하였으며, 열처리를 한 경우에는 감소하였다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2002년도 추계기술심포지움논문집
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• pp.55-58
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• 2002

The possibility of SnCuX Solder as alternative for Pb-free Solder have been investigated in this study. SnCuX Solder balls(500${\mu}{\textrm}{m}$) were placed on Si-wafer which is Al/Ni/Cu(500nm/$4{\mu}{\textrm}{m}$/$4{\mu}{\textrm}{m}$)UBM layer. After reflow soldering at $250^{\circ}C$, shear strength and microstructure were analyzed. The results showed that the shear strength(500gf) of SnCuX was higher than that of SnCuX at $230^{\circ}C$ and $Cu_6Sn_5$ intermetallic compounds were formed between Cu and SnCuX Solder layers

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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• pp.265-269
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• 2003

Sn(또는 SnAg)/Ni(P)와 Sn/Cu 계의 열사이클동안 형성되는 금속간화합물에 의해 유기되는 응력의 변화를 in-situ로 관찰하였다. Sn(또는 SnAg)/Ni(11.7P) 박막은 계면반응으로 인해 $Ni_3P$와 $Ni_3Sn_4$ 상이 형성되고 이때 인장응력이 발생하였으며, 한편, Sn(또는 SnAg)/Ni(3P) 박막의 계면반응에 의해서는 동일한 $Ni_3P$와 $Ni_3Sn_4$ 상이 형성됨에도 불구하고 압축응력이 발생하였다. SmAg를 사용할 때 형성되는 $Ag_3Sn$이 응력에 미치는 영향은 거의 없었다. Sn/Cu 박막의 경우는 계면반응 초기에는 인장응력이 발생하였고 어느 정도 이상 반응이 진전됨에 따라 압축응력이 발생하였고 최종적으로 $Cu_3Sn$ 상이 형성되었다. 초기의 인장응력은 계면에서 원자들의 intermixing 베 의한 것이고 압축응력은 Sn 방향으로 일방향 성장하는 금속간화합물 형성에 기인한다.

• 마이크로전자및패키징학회지
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• 제7권1호
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• pp.19-24
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• 2000

Workstation이나 PC seven옹 메모리칩의 고밀도 실장을 위한 stack chips package (SCP)를 만들기 위해서는 여러 개의 리드프레임이 수직으로 접합되어야 한다. 이를 위하여 Cu리드프레임 위에 전기화학증착법으로 Sn 또는 Sn/Ag를 도금한 후 XRD와 SEM으로 미세구조를 분석하였다. 그리고 두 개의 시편을 $250^{\circ}C$에서 10분간 열처리하고 가압하여 접합한 후 전단강도를 측정하여 비교하였다. Sn만이 도금된 경우, Sn과 Cu리드프레임이 반응하여 $Cu_3Sn$이 생성되었고, Sn/Ag의 경우에는 $Cu_3Sn$외에 Sn과 Ag가 반응하여 $Ag_3Sn$이 형성되었다. 전단강도는 Sn/Ag의 경우가 Sn만이 도금되었을 때보다 약 1.2배 정도 강하였다. 이는 접합면에 형성된 $Ag_3Sn$이 전단강도를 강화시켰기 때문이다.

• 한국표면공학회지
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• 제22권1호
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• pp.3-9
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• 1989

The intermetallic compount formation, growth rections, and growth kinetices as functions of the aging temperaturess, time, and the condition of substarte have invedtigted in the Sn/Cu and Sn/Ni bimetal couples. The η'-phase (Cu6Sn5) and $\delta$-phase (Ni3Sn4) were only found to grow at 20 and $70^{\circ}C$in the Sn/Cu and Sn/Ni bimetallic coples repectively. Above that temperatures, all other compounds were formed in sequence of high Sn content plase and the metastable Cu41Sn11 was formed at agend $200^{\circ}C$. The ectivation energy for the growth of intermetallic compounds was 14.7Kxal/mole in the Sn/Cu interface and 26.7Kcal/mole in the Sn/Ni interface.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년 추계학술발표대회 개요집
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• pp.169-171
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• 2006

Solderability and reaction properties were investigated for four Pb-free alloys as a function of Ag contents; Sn-4.0Ag-0.5Cu, Sn-3.0Ag-0.5Cu, Sn-2.5Ag-0.5Cu, and Sn-1.0Ag-0.5Cu. The alloy of the lowest Ag content, i.e., Sn-1.0Ag-0.5Cu, showed poor wetting properties as the reaction temperature decreased to 230oC. Variation of Ag concentration in the Sn-xAg-0.5Cu alloy shifted exothermic peaks indicating the undercooling temperature in DSC curve. For the aging process at 170oC, the thickness of IMCs at the board-side solder/Cu interface increased with the Ag concentration.

• 한국표면공학회지
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• 제36권5호
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• pp.386-392
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• 2003

The electroplating process for a solder bump which can be applied for a flip chip was studied. Si-wafer was used for an experimental substrate, and the substrate were coated with UBM (Under Bump Metallization) of Al(400 nm)/Cu(300 nm)Ni(400 nm)/Au(20 nm) subsequently. The compositions of the bump were Sn-Cu and eutectic Sn-Pb, and characteristics of two bumps were compared. Experimental results showed that the electroplated thickness of the solders were increased with time, and the increasing rates were TEX>$0.45 <\mu\textrm{m}$/min for the Sn-Cu and $ 0.35\mu\textrm{m}$/min for the Sn-Pb. In the case of Sn-Cu, electroplating rate increased from 0.25 to $2.7\mu\textrm{m}$/min with increasing current density from 1 to 8.5 $A/dm^2$. In the case of Sn-Pb the rate increased until the current density became $4 A/dm^2$, and after that current density the rate maintains constant value of $0.62\mu\textrm{m}$/min. The electro plated bumps were air reflowed to form spherical bumps, and their bonded shear strengths were evaluated. The shear strength reached at the reflow time of 10 sec, and the strength was of 113 gf for Sn-Cu and 120 gf for Sn-Pb.

• Journal of Electrochemical Science and Technology
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• 제10권3호
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• pp.329-334
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• 2019

Sn-Cu alloy powders were prepared via a simple chemical reduction method for the negative electrode materials in lithiumion batteries. The addition of Cu can suppress the growth of Sn particles during synthetic process. Furthermore, the Cu also acts as a matrix phase against the volume change during cycling. With increasing amount of the Cu, a stable $Cu_6Sn_5$ phase formed in the Sn-Cu alloy and its cycle performance greatly enhanced depending on the Cu content. To promote the generation of the $Cu_6Sn_5$ phase, the synthesis temperature is raised to $60-100^{\circ}C$ from the ambient temperature. The Sn-Cu alloy powders prepared at elevated temperatures showed remarkable cycle performances. The Sn-Cu alloy powder obtained at $60^{\circ}C$ exhibited a significantly high volumetric capacity of over 2,000 mAh/cc at the 50th cycle.

• 마이크로전자및패키징학회지
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• 제15권4호
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• pp.31-39
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• 2008

캐비티 형성이 불필요한 MEMS 캡 본딩을 위해 전기도금법을 이용하여 Cu/Sn rim 구조를 형성하였으며, $25{\sim}400{\mu}m$ 범위의 rim 폭에 따른 본딩특성을 분석하였다. Cu/Sn rim의 폭이 증가함에 따라 rim 패키지 내부의 유효 실장면적비가 감소하는 반면에 파괴하중비가 증가하며, Cu/Sn rim 폭이 150 ${\mu}m$일 때 유효 실장면적비와 파괴하중비를 최적화할 수 있을 것으로 예측되었다. 폭 25 ${\mu}m$ 및 폭 50 ${\mu}m$인 Cu/Sn rim 접합부에서는 모든 계면에서 본딩이 이루어진 반면에, 100 ${\mu}m$ 이상의 폭을 갖는 rim 접합부에서는 Sn 도금표면의 거칠기에 의해 본딩이 이루어지지 않은 기공 부위가 관찰되었다.