Papers by Keyword: Nanoindenter

Abstract: The mechanical properties of anodic oxide films of Nb, Ta and Zr were studied by the nanoindentation method. Anomalously high elastic recovery after deformation was observed for oxides with thickness of 20 nm. An analogue of this behavior can be elastic membrane fixed on soft base that does not prevent the membrane from bending. Increase of the oxide thickness to 300 nm reduced the effect associated with the high elasticity of oxide and easy deformation of the soft metal substrate, and was accompanied by an increase in the plastic component of deformation, which is similar to the behavior of ceramic materials with low elastic and significant residual plastic deformation.

Abstract: Effect of microstructure size and type on the hardness for the duplex steel were disclosed by using of optical microscope (OM), scanning electron microscope (SEM) and nanoindenter for the samples hot compressed under different temperature with reduction of 10%, 30%, 50% and 70%. OM and SEM were used to measure the average martensite lamellar width, space and indenter morphology. nanoindenter test characterized the microstructure hardness for the samples under different process. Experiment results show that martensite hardness for the sample hot compressed at 950°C has larger diversity than that of sample hot compressed at 1200°C. The martensite hardness fluctuation range for the sample compressed at 950°C is almost from about 7GPa to 12GPa, while, for the sample compressed at 1200°C, the fluctuation range is basically from about 9GPa to 12GPa. However, the average hardness for the samples hot compressed at 950°C is comparably smaller, which is related with lower quench temperature. The larger martensite hardness fluctuation is mainly related with induced ferrite formation and finer martensite lamellar width. For the ferrite phase, the hardness fluctuation range is lower.

Abstract: We report an investigation of the formation of triangular defects (TDs) in 4H–SiC expitaxial layers using Kelvin probe force microscopy (KPFM) and a nano-indenter. The results provide valuable information on the crystallographic structure, including the polytype nature of the TDs and surface potential profile. The TDs were also characterized using micro-Raman spectroscopy and high-resolution transmission electron microscopy. We found that the TDs were composed of a thick 3C-SiC band, as well as stacking faults (SFs) in the 4H-SiC epilayer.

Abstract: In semiconductor packaging, conventional test procedures for evaluating mechanical properties of ball bonded gold wire bonding are well established. However these tests do not provide clear understanding related to the strength mechanism leading to improper reliability data. The nanoindentation approach, uses equipment called nanoindenter, gives advances mechanical (sub-micromechanical) characterization, particularly the combination effect of elastic and plastic deformation. Wire bonding process was prepared using thermosonic-wire bonding technology with 25m diameter gold wire and copper as substrate. To obtain mechanical properties, ball-bonded was cross-sectioned diagonally before indented at various locations. Results show that mechanical properties vary according the locations throughout the surface; at the centre, at the edge and at the area near intermetallics layer. This indicates test location plays important role in determining ‘meaningful’ mechanical properties.

Abstract: A series of the magnesium apatite coatings according to (Ca_10-xMg_x)(PO₄)₆(OH)₂, where x = 0 to 2, was synthesized through a sol-gel dip-coating method. The roughness of the magnesium coatings increased as more magnesium incorporated into the coatings. The mechanical properties of the coatings were analyzed with Nanoindentor. The incorporation of magnesium decreased the hardness and the Young’s modulus of the coating. The X-ray Photoelectron Spectroscopy (XPS) analysis revealed that only part of magnesium was incorporated into the apatite structure while the rest existed in the form of MgO in the coating.

Abstract: For producing high-quality components through a nanoimprint lithographic (NIL) process, it is important to measure quantitative properties about the behavior of polymers with regard to thermal-nano variation. NanoScale indents can be used as cells for molecular electronics and drug delivery and slots for integration into nanodevices; they can be used to detect defects for tailoring the structure and properties. This study evaluates the mechanical characteristics of polymers, such as Polymethylmetacrylate (PMMA) and COP (Cyclo-olefin Polymer), at high temperatures for the manufacture of nano/micro-sized polymers through thermal nanoindentation at high temperatures. At high temperatures, the mechanical properties of polymers exhibit extreme variation. When a polymer is heated, it becomes softer than at room temperature. In this regard, it is especially important to study the mechanical properties of polymers at high temperatures.

Abstract: Underfilling is the vital process to reduce the impact of the thermal stress that results from the mismatch in the co-efficient of thermal expansion (CTE) between the silicon chip and the substrate in Flip Chip Packaging. This paper reported the pattern of underfill’s hardness during curing process for large die Ceramic Flip Chip Ball Grid Array (FC-CBGA). A commercial amine based underfill epoxy was dispensed into HiCTE FC-CBGA and cured in curing oven under a new method of two-step curing profile. Nano-identation test was employed to investigate the hardness of underfill epoxy during curing steps. The result has shown the almost similar hardness of fillet area and centre of the package after cured which presented uniformity of curing states. The total curing time/cycle in production was potentially reduced due to no significant different of hardness after 60 min and 120 min during the period of second hold temperature.

Abstract: Fracture surface and surface of two kind of membrane of antibacterial bone china, which includes 3% and 5% of weight of composite phosphate containing rare earth respectively, were characterized by SEM and nanoindenter, respectively. Nanohardness and nanoscale friction coefficients were measured by nanoindenter. Friction coefficients were conducted at the maximal load being 300un,500un,1000un and scratching speed 15um/s, 0.75um/s, 0.5um/s, respectively. The nanohardness and friction coefficients of ceramic membrane including 3% and 5% of rare earths are 2.03GPa,0.18282 and 8.54GPa,0.051998, respectively. The two kind of ceramic membrane has stable nanotribology property. Obvious plastic flow and pile-up scratch impression of ceramic membrane including 3% rare earths is observed by AFM in situ imaging, but scratch impression of 5% has no plastic flow and take on the sink-in topography. Nanohardness and friction coefficients of this two kind of ceramic membrane have strong relationships each other but weak relations with elastic modulus.

Abstract: Electroplated nickel manufactured via the LIGA process, offers the possibility of stronger structure and connectors in a micro electro mechanical systems (MEMS). In this study, the mechanical properties of electroplated Nickel thin film were characterized using two methods; tension test and nano-indentation test. In tension test, a linear guided motor was used as actuator and the applied force was measured using a load cell. Strain was measured with a dual microscope that obtains the displacement of two separated zone by the tracking process of the image captured with CCD camera. In indentation test, elastic modulus was measured using a CSM(continuous stiffness measurement) module. Two types of specimen were prepared in the same wafer and tested after four months of aging, which reduces the variation of properties caused by fabrication condition and aging effect. The tension specimen is 15 µm thick and 300 µm wide. The indentation specimen is also 15 µm thick. Young's modulus were measured by two different testing methods and compared quantitatively.