Effect of CeO2 particles on the high phosphorus electroless Ni layer
Electroless Ni (EN) technology is widely used in electronic package field and the high phosphorus composite EN technology was studied. In this paper, we discussed the influence of nano-CeO2 and micro-CeO2 particles with different amounts when they were added in high phosphorus content Ni-P composite coating. The microstructure and crystal structure of the coating were observed by scanning electron microscope (SEM) and X-ray diffraction analysis (XRD) respectively. The results showed that whether nano-CeO2 or micro-CeO2, both refined the grain, increased the specific surface area, however the micro-CeO2 particles made more obvious effect. As the XRD result showed, the peak gradually become gentle, the coating turned into amorphous which may cause by the CeO2 particles absorbed in the grain boundary and crystal defects. The results indicated the CeO2 deposited with the coating very well. Finally, the corrosion resistance of the coating was tested with the method of electrochemical impedance (EIS) and linear polarization. The results were unified. When the dosage is 5g/L, the corrosion resistance was the best. However, lower corrosion resistance was got when excessive CeO2 particles were added which may affect by the catalytic property.
Improvement of Wire Bond Strength to Electroless Au/Pd/Ni-P Plating Pads on Printed Wiring Boards by Knocking in Plating Bath
Au wire bond strength on Cu interconnects printed wiring boards was investigated for electroless Au/Pd/Ni-P pads plating prepared with knocking substrates in plating baths. A scanning electron microscope revealed that the surface of Ni-P plating formed with knocking was smoother than that of Ni-P plating formed without knocking. Furthermore, X-ray photoelectron spectroscopy indicated that no a Ni peak was recognized on Au/Pd/Ni-P plating formed with knocking, while a Ni peak was observed on ones formed without knocking. The wire bond strength to Au/Pd/Ni-P plating pads formed with knocking was larger than that to ones formed without knocking. These findings are due to removing hydrogen from a Ni-P surface by knocking substrates during formation of Ni-P plating. © The Electrochemical Society of Japan, All rights reserved.
Do Arab public opinion support policies of regional powers in MENA? View from Tunisia
ABSTRACT The Arab Uprisings and subsequent events continue to transform policies of regional and major powers toward the Middle East and North Africa. These powers have shown different approaches toward the Uprisings, ranging from support for the status quo to endorsing regime changes. Their policies have also exerted a significant impact on the course of events. Despite this growing importance and implications of policies of regional powers on the Uprisings and the Syrian conflict, we still do not know much about how the public assesses these policies and to what extent domestic cleavages shape these assessments. Using a nationally representative original survey conducted in 2014 in Tunisia, this study examines the perceptions of the policies of France, Turkey, and Saudi Arabia towards the Uprisings and the Syrian conflict. It finds that French and Turkish policies about the Uprisings have garnered substantial support among citizens, whereas most citizens negatively assess the Saudi policies. On the other hand, the majority of Tunisians negatively assess all these countries’ policies toward the Syrian conflict. Another major finding suggests that political identity reflecting secular/religious cleavages shapes how citizens view the policies of these three countries toward both issues, but its effect is higher in assessing the Uprisings.