In this study, we report the microstructural evolution and shear strength of an Sn-Sb alloy, used for die attach process as a solder layer of backside metal (BSM). The Sb content in the binary system was less than 1 at%. A chip with the Sn-Sb BSM was attached to a Ag plated Cu lead frame. The microstructure evolution was investigated after die bonding at 330 °C, die bonding and isothermal heat treatment at 330 °C for 5 min and wire bonding at 260 °C, respectively. At the interface between the chip and lead frame, Ni3Sn4 and Ag3Sn intermetallic compounds (IMCs) layers and pure Sn regions were confirmed after die bonding. When the isothermal heat treatment is conducted, pure Sn regions disappear at the interface because the Sn is consumed to form Ni3Sn4 and Ag3Sn IMCs. After the wire bonding process, the interface is composed of Ni3Sn4, Ag3Sn and (Ag,Cu)3Sn IMCs. The Sn-Sb BSM had a high maximum shear strength of 78.2 MPa, which is higher than the required specification of 6.2 MPa. In addition, it showed good wetting flow.

Zintl phase Mg3Sb2 is a promising thermoelectric material in medium to high temperature range due to its low band gap energy and characteristic electron-crystal phonon-glass behavior. P-type Mg3Sb2 has conventionally exhibited lower thermoelectric properties compared to its n-type counterparts, which have poor electrical conductivity. To address these problems, a small amount of Sn doping was considered in this alloy system. P-type Mg3Sb2 was synthesized by controlled melting, pulverizing, and subsequent vacuum hot pressing (VHP) method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate phases and microstructure development during the process. Single phase Mg3Sb2 was successfully formed when 16 at.% of Mg was excessively added to the system. Nominal compositions of Mg3.8Sb2-xSnx (0 ≤ x ≤ 0.008) were considered in this study. Thermoelectric properties were evaluated in terms of Seebeck coefficient, electrical conductivity, and thermal conductivity. A peak ZT value ≈ 0.32 was found for the specimen Mg3.8Sb1.994Sn0.006 at 873 K, showing an improved ZT value compared to intrinsic one. Transport properties were also evaluated and discussed.

Zr-0.8Sn합금의 재결정에 미치는 V, Sb의 영향을 조사하기 위해 냉간 압연 후 여러 온도 조건에서 열처리된 시편의 미세조직을 편광광학현미경, SEM, TEM으로 관찰하였고 미소경도계로 경도값을 측정하였다. 미세조직을 관찰한 결과 V과 Sb의 첨가에 의해 재결정이 지연되었으며, 재결정 완료 후의 결정립 성장도 억제됨이 관찰되었다. 특히 Sb는 V보다 재결정을 완료하는데 필요한 온도를 상승시키므로 재결정을 지연시키는 효과가 더욱 큰 것으로 생각된다. 이 처럼 첨가원소가 증가함에 따라 재결정에 늦어지고 결정립이 미세화 되는 것은 V이나 Sb 첨가에 의해 형성된 석출물이 전위나 입계의 이동을 방해하기 때문인 것으로 사료된다.

전형적인 f-f 및 nf-f 공정합금계로 분류되는 Sb-InSb 및 Sn-Bi 합금계를 일방향 응고시켜서 성장속도에 따른 전기비저항값의 변화를 조사함으로써 미세조직의 이방성을 전기비저항의 특성으로 분석하고자 하였다. Sb-InSb 계의 경우 26-34wt.% In, Sn-Bi 계의 경우 53-65wt.% Bi의 조성을 갖는 공정합금을 진공봉합시켜 Bridgman형의수직관상로에서 일방향응고시켰다. 일방향응고 시편을 횡단면 및 종단면으로 절단 채취하여 미세조직을 관찰한 후 전기비저항을 측정하였다. Sb-InSb , Sn-Bi공정복합조직의 경우 모두 성장속도의 증가에 따라 성장방향에 수평한 방향의 비저항값(ρ┴)은 감소하였으며, Sb InSb 공정복합조직의 경우 특히 성장 속도의 증가에 따르는 미세조직상의 두가지 변화 즉, 상경계면적(phase boundary area)의 증가와 fiber방향성의 감소는 공히 ρ ll 값을 증가시키는 반면 ρ┴ 값에는 서로 상반된 영향을 끼쳤다. 또한 성장속도의 증가에 따라 점차 조직의 이방성이 상실되었다. 이와 같이 측정된 전기비저항은 미세조직특성과 잘 일치하는 바 전기비저항 측정은 조직 특성분석의 유효한 도구가 될 수 있다.

For electrolysis process using an insoluble electrode, electrochemical performance was greatly affected by the manufacturing method and procedure, such as the firing temperature, pre-treatment, type of precursor solution, coating method, electrode material, etc. Components of the electrode therein is one of the most important factors in electrochemical reaction. To achieve such characteristics, a appropriate ratio of the electrode material should be carefully chosen. The aim of this research was to apply experimental design method in the optimization of electrode component for the maximum generation of oxidants in electrochemical oxidation process. Mixture design, especially expanded simplex lattice design, in DOME (design of mixture experiments) with Design Expert - commercial software - was used to analyze the data. Analysis of variance (ANOVA) showed a high coefficient of determination (R2) value of 0.9470, thus ensuring a satisfactory adjustment of the 3rd order special cubic regression model with the experimental data. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the TRO generation concentration and independent variables(mol ratio of 3 electrode components) in a real unit: TRO generation concentration (mg/L) = TRO conc. = 98.25×[Ir] + 49.71×[Sn] + 95.29×[Sb] 16.91×[Ir]×[Sn] - 29.47×[Ir]×[Sb] 22.65×[Sn]×[Sb] + 703.19 ×[Ir]×[Sn]×[Sb]. The optimized formulation of the 3 component electrode for an high TRO (total residual oxidants) generation was acquired at mol ratio of Ir 0.406, Sn 0.210, Sb 0.384 (desirability d value, 1).