Papers by Author: Rozaidi Rashid

Abstract: Melt compounding technique was employed to prepare thermoplastic natural rubber (TPNR) nanocomposite. The ultrasonic bath was used to improve the filler-matrix interfacial adhesion. TPNR nanocomposites were prepared in the ratio of (70:20:10) from polypropylene (PP), natural rubber (NR) and liquid natural rubber (LNR) as a compatibilizer, with 4% NanolinDK4. The clay layers were found to be separated further with ultrasonic treatment as compared to the sample without ultrasonic treatment as exhibited from X-ray diffraction. Young's modulus, tensile strength and elongation at break of TPNR nanocomposites increased with ultrasonic treatment, the optimum results achieved at 3h. .The results obtained from dynamic mechanical analysis (DMA) curves indicate that the addition of MWNTs led to an increase in the storage modulus E' and loss modulus E'' with maximum value is obtained at 3 hours. The glass transition temperature (Tg) also increases with Ultrasonic treatment. Ultrasonic treatment can promote the dispersion of the clay in TPNR also improve the compatibility of organoclay filler and the TPNR matrix.

Abstract: Nanocomposites prepared from blend of high density polyethylene (HDPE), natural rubber (NR) and organoclay were melt compounded using an internal mixer. The phase morphology and mechanical properties of this thermoplastic natural rubber nanocomposites samples were examined. The transmission electron microscope (TEM) and wide angle X-ray scattering (WAXS) was used to determine the exfoliation of organoclay in this blend. The tensile and Izod impact test were used to evaluate the mechanical properties of HDPE/organoclay nanocomposites with and without the presence of NR. The Izod impact results shows an improvement more than 300% with addition of 10% NR content in the matrix. The X-ray diffraction results indicated intercalation of blend into the silicate interlayer of nano-filler I.44P and partially exfoliation of silicate layer into the blend. The SEM morphology revealed that there was some part of uneven dispersion of organoclay in the blend.

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: Underfilling is the preferred process to reduce the impact of the thermal stress that results from the mismatch in the coefficient of thermal expansion (CTE) between the silicon chip and the substrate in Flip Chip Packaging. Voids formation in underfill is considered as failure in flip chip manufacturing process. Voids formation possibly caused by several factors such as poor soldering and flux residue during die attach process, voids entrapment due moisture contamination, dispense pattern process and setting up the curing process. This paper presents the optimization of two steps curing profile in order to reduce voids formation in underfill for Hi-CTE Flip Chip Ceramic Ball Grid Array Package (FC-CBGA). A C-Mode Scanning Aqoustic Microscopy (C-SAM) was used to scan the total count of voids after curing process. Statistic analysis was conducted to analyze the suitable curing profile in order to minimize or eliminate the voids formation. It was shown that the two steps curing profile provided solution for void elimination.