Ultra-fine pitch palladium-coated copper wire bonding: Effect of bonding parameters

Copper (Cu) wire bonding has become a mainstream IC assembly solution due to its significant cost savings over gold wire. However, concerns on corrosion susceptibility and package reliability have driven the industry to develop alternative materials. In recent years, palladium-coated copper (PdCu) wire has become widely used as it is believed to improve reliability. In this paper, we experimented with 0.6 ml PdCu and bare Cu wires. Palladium distribution and grain structure of the PdCu Free Air Ball (FAB) were investigated. It was observed that Electronic Flame Off (EFO) current and the cover gas type have a significant effect on palladium distribution in the FAB. The FAB hardness was measured and correlated to palladium distribution and grain structure. First bond process responses were characterized. The impact of palladium on wire bondability and wire bond intermetallic using a high temperature storage test was studied.     

Photocatalytic degradation of organic dye using titanium dioxide modified with metal and non-metal deposition

In this study, photocatalytic degradation of methyl orange (MO) as an example of organic dye was investigated using different wt% Pd-loaded and N-doped P-25 titanium dioxide (TiO₂) nanoparticles, as example of metal and nonmetal-doped TiO₂, respectively. The Pd-loaded and N-doped TiO₂ photocatalysts were prepared by post-incorporation method using K₂PdCl₄ and urea, respectively, as precursors. A variety of surface analysis techniques were used for characterization of surface and functional group while using ultraviolet/visible (UV–vis) analysis for monitoring photocatalytic degradation of MO. Kinetic parameters were obtained using Langmuir-Hinshelwood model to determine the degradation rate constants. It was found that the metal-loaded titanium dioxide degraded MO in water at a higher rate than did non-metal-loaded titanium dioxide fabricated by using the post-synthesis method. Also, the pure P25-TiO₂ degraded MO more than N-doped TiO₂ because of decreased surface area by particle agglomeration after being made by the post-incorporation method.     

电子接插件的快速连续电镀方法

介绍了适于电子接插件的快速连续电镀金、钯及Ｓｎ－Ｐｂ合金工艺的流程、操作要领等,对镀层的性能进行了分析比较,提出了快速电镀应解决的问题。     

用DSPCF分光光度法测定钯

在室温下以硝酸为介质,钯与DSPCF形成有色络合物,其表观摩尔吸光系数ε_(520)=1.2×10~4,络合物组成为Pd(Ⅱ):DSPCF=1:2。其特点是在室温下发生显色反应,当加入HNO_3使介质达1.75N时,只有Pd(Ⅱ)—DSPCF红色络合物不褪色,可用于铂钯二次精矿等的测定。     

扫描电镜和EDS研究钯的加入对SAPO—5分子筛合成及结构的影响

在硅磷酸铝反应物凝胶中采用引入钯盐共晶化的方法，一步合成了ＰｄＳＡＰＯ－５分子筛。通过不同温度的水热处理来对分子筛材料进行改性，用扫描电子显微镜观察处理前后样品的晶形变化，用ＥＤＳ分析不同晶粒上的元素组成。     

Metal hydride batteries research using nanostructured additives

We describe here, our recent research efforts to improve the capacity of metal hydride batteries using nanostructured additives. Nanostructured additives of palladium, copper and nickel were incorporated separately into the negative electrode of the metal hydride batteries. The nanomaterials were synthesized by template-based methods and characterized by scanning electron microscopy. These nanomaterials were incorporated in the negative electrode of the metal hydride battery and the electrochemical performance at 2 C rate was studied. The nanomaterial-incorporated negative electrodes all showed increased cell voltage and negative electrode potential compared to that of a pristine cell. The increase in discharge capacity for a cut-off voltage of 1 V depends on the nanomaterial incorporated and a comparative analysis of the performance of the different batteries is presented.     

Adhesion and Percolation Parameters in Two Dimensional Pd–LSCM Composites for SOFC Anode Current Collection

This paper is concerned with palladium–(La_0.75Sr_0.25)_0.97Cr_0.5Mn_0.5O₃ (LSCM) composite current collectors for solid oxide fuel cells (SOFCs); the composites, which are in a 2D configuration (thickness of about 8–10 µm), are deposited upon an LSCM electrode layer on top of an yttria zirconia electrolyte substrate. The influence of the LSCM particle size on the adhesion between palladium and LSCM are reported and discussed. Compositions using four different LSCM particle sizes (0.21, 0.49, 0.64, and 0.81 µm) with sintered Pd particle sizes approaching 10 µm are investigated. The best bonding is obtained when smaller particles are used. The electrical dc conductivity of the composite is reported as a function of the palladium volume fraction for all used LSCM particle sizes. The measured experimental values present typical insulating–conductive percolation. However, the transition occurs at ～33% of the conductive phase, that is, a lower percentage than for 2D ideal systems and a higher percentage than for 3D ideal systems. This is consistent with lower‐dimension percolation for a system of large‐grained conductors and small‐grained insulators. The general effective media (GEM) equation is used to fit the experimental data, and the two main parameters (the threshold point ?_c and the exponent t) are defined.     

A low-power readout circuit for nanowire based hydrogen sensor

This paper presents a fully integrated lock-in amplifier intended for nanowire gas sensing. The nanowire will change its conductivity according to the concentration of an absorbing gas. To ensure an accurate nanowire impedance measurement, a lock-in technique is implemented to attenuate the low frequency noise and offset by synchronous demodulation or phase-sensitive detection (PSD). The dual-channel lock-in amplifier also provides both resistive and capacitive information of the nanowire in separate channels. Measurement results of test resistors and capacitors show a 2% resolution in the resistance range 10-40 kΩ and a 3% resolution in the capacitance range 0.5-1.8 nF. Moreover, a 28.7-32.1 kΩ impedance variation was measured through the lock-in amplifier for a single palladium nanowire that was exposed to a decreasing hydrogen concentration (10% H₂ in N₂ to air). The chip has been implemented with UMC 0.18 μm CMOS technology and occupies an area of 2 mm². The power consumption of the readout circuit is 2 mW from a 1.8 V supply.     

Characterization of palladium supported on sulfated zirconia catalysts by DRIFTS, XAS and n-butane isomerization reaction in the presence of hydrogen

Palladium supported on sulfated zirconia (PdSZ) has been characterized by the n-butane isomerization reaction in the presence of hydrogen, X-ray absorption spectroscopy (XAS) and diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) of adsorbed carbon monoxide. Catalyst calcination at 873 K followed by hydrogen reduction at 513 K results in the formation of 30–40 Å Pd metal clusters, but the surface can only weakly adsorb CO, though stronger than Pd-free, sulfated zirconia catalysts. In the presence of hydrogen, PdSZ has a lower n-butane isomerization activity than SZ, and the Pd function cannot stabilize the reaction at low H₂/n-butane ratios.     

Solvent-free oxidation of benzyl alcohol using titania-supported gold–palladium catalysts: Effect of Au–Pd ratio on catalytic performance

The oxidation of benzyl alcohol with molecular oxygen under solvent-free conditions has been investigated using a range of titania-supported Au–Pd alloy catalysts to examine the effect of the Au–Pd ratio on the conversion and selectivity. The catalysts have been compared at high reaction temperature (160 °C) as well as at 100 °C, to determine the effect on selectivity since at lower reaction temperature the range of by-products that are formed are limited. Under these conditions the 2.5 wt.% Au–2.5 wt.% Pd/TiO₂ was found to be the most active catalyst, whereas the Au/TiO₂ catalyst demonstrated the highest selectivity to benzaldehyde. Toluene, formed via either a hydrogen transfer process or an oxygen transfer process, was observed as a major by-product under these forcing conditions.