No abstract

The sticking of product material to injection molding tools is a serious problem, which reduces productivity and reliability. Depositing alloy nitride coatings (TiN, ZrN, CrN, and TiAlCrN) using closed field unbalanced magnetron sputter ion plating and electrodeposition of chromium, and characterizing their surface free energies in the temperature range 20-120 C have led to the development of a non-sticking (with a low surface free energy) coating system for semiconductor IC packaging molding dies. The contact angles of water, diiodomethane and ethylene glycol on the coated surfaces were measured at temperatures in the range 20-120 C using a Dataphysics OCA-20 contact angle analyzer. The surface free energy of the coatings and their components (dispersion and polar) were calculated using the Owens-Wendt geometric mean approach. The surface roughness of these coatings were investigated by atomic force microscopy (AFM). The adhesion force of these coatings were measured using direct tensile pull-off test apparatus. The experimental results revealed that TiAlCrN, CrN and ZrN coatings outperformed Hard-Cr and TiN coatings in terms of anti-adhesion, and thus have the potential as working layers for injection molding industrial equipment, especially in semiconductor IC packaging molding applications.

A systematic study of the photocurrent activity and the nanostructure of a TiO 2 indium tin oxide ͑ITO͒ electrode prepared using reactive sputtering was carried out. The photocurrent was measured in 0.1 M NaClO 4 aqueous solution using an amperometric method under irradiation. The total conversion efficiency (eff) was estimated. Various photoelectrode TiO 2 films were synthesized by controlling deposition times, sputtering powers, total pressures, and the mole percentage of oxygen used in reactive sputtering. The physical properties of the TiO 2 film such as the crystal phase, particle size, bandgap energy, and thickness were characterized using X-ray diffraction ͑XRD͒, scanning electron microscopy ͑SEM͒, UV-visible spectroscopy, and profilometry. The results indicated that the optimal photocurrent was obtained at a thickness of approximately 1.2 m and mean particle size of approximately 50 nm. The ͑112͒-preferred orientation anatase shows higher photocurrent than ͑101͒-orientation anatase due to its regular columnar structure. The phase diagram of the prepared TiO 2 film defined by sputtering power and total pressure was also studied.

The photoelectrochemical oxidation of nitrite ion on a rutile form of a TiO2 particulate film immobilized on a titanium plate (TiO2/Ti) with applying bias potential was studied. The experimental results indicate that the oxidation of nitrite ion is mainly affected by the applied potential and irradiation of power of light, and the oxidation is also independent of both nitrite ion concentration and pH. Theoretical analysis results correlate well with experimental ones, indicating that the reaction is of zero order with respect to the concentrations of nitrite ion and the hydroxyl ion. Meanwhile, the reaction is of 0.30 and 0.80 order with respect to the applying bias potential and the output power of light, respectively.