Z. X. Qiu

Bio: Z. X. Qiu is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 30 citations.

Local Deposition of Ni‐P Alloy on Aluminum by Laser Irradiation and Electroless Plating

Abstract: Electroless plating of Ni‐P has been widely applied, since it is not selective to substrate materials with respect to electric conductivity and can provide excellent coverage of the substrate, especially those with complicated shapes. Much effort has been made to understand the deposition process, the effects of additives, and the structure and properties of the deposits in Ni‐P electroless deposition. 1‐9 In electroless plating, activation of the substrate is an indispensable pretreatment to initiate the reduction of nickel ions and to improve adhesion between deposit and substrate. Successive immersion in SnCl2 and PdCl2 solutions is a conventional activating process before the Ni‐P electroless plating. Here the specimen is initially immersed in SnCl 2 solution for 1‐2 min at room temperature to adsorb Sn 21 ions on the surface. During the second immersion in PdCl2 solution, Pd 21 ions are reduced by Sn 21

Electrochemical Micromachining of Titanium through a Laser Patterned Oxide Film

Abstract: Selective dissolution of titanium through a laser patterned oxide film has been achieved in a 3M sulfuric acid-methanol electrolyte. The 250 nm thick oxide film was formed anodically on a flat titanium surface in 0.5 M sulfuric acid. The patterning of the film was obtained by local irradiation using a long pulse XeCl eximer laser. Electrochemical dissolution at irradiated lines on the oxide film yielded well-defined grooves comparable to those resulting from electrochemical micromachining through a photoresist mask. The described process permits electrochemical micromachining of titanium without photoresist and thus can lead to new applications of this technique.

Improved adhesion property and electromagnetic interference shielding effectiveness of electroless Cu‐plated layer on poly(ethylene terephthalate) by plasma treatment

Abstract: To develop high-quality electromagnetic interference (EMI) shielding materials, the effect of plasma pretreatment with various gases prior to Cu plating was investigated. Plasma treatment increased the surface roughness in the decreasing order of Ar > O2 > NH3, but adhesion of the Cu layer on poly(ethylene terephthalate) (PET) film increased in the following order of O2 < Ar < NH3, indicating that the appropriate surface roughness and introduction of an affinitive functional group to Pd on the surface of the PET film were key factors for improving adhesion of the Cu layer. As investigated by XPS analysis, plasma treatment with NH3 produced N atoms on the PET film, which enhances the chemisorption of Pd2+ on PET film, resulting in improved adhesion and shielding effectiveness of the Cu layer deposited on the Pd-catalyzed surface, because of the high affinity of Pd2+ for nitrogen. Comparatively, O2 plasma treatment allowed the chemisorption of more Sn2+ than of Pd2+ due to a lack in the affinity of Pd2+ for oxygen, resulting in the lowest Pd3d/Sn3d ratio; thereby, the lowest EMI–shielding effectiveness (SE) value was obtained. In addition, fairly low adhesion was obtained with Ar plasma-treated PET, even though the PET surface was significantly etched with Ar plasma, due to introduced oxygen groups on the PET surface. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1369–1379, 2002; DOI 10.1002/app.10272

Effects of catalyst accelerator on electromagnetic shielding in nonelectrolytic Cu-plated fabrics

Abstract: The effects of etching and catalyst accelerating conditions on microstructures of copper films and electromagnetic interference (EMI) shielding effectiveness (SE) of nonelectrolytic copper-plated fabrics were investigated. Copper films were coated onto polyester fabrics by a conventional nonelectrolytic copper plating process. Comparison of two etchants had the result where uniform deposition of Cu particles in the smaller size was observed using acidic etchant, which provided the better EMI SE than alkaline etchant. We found that KCl was the better catalyst accelerator than commonly used SnCl2. EMI SEs and conductivities of copper-plated fabrics increased as the concentration of KCl increased up to 0.1 mole/l and then decreased with further addition.