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Lead frame tape is a crucial support for lead frames in the IC assembly process. The tape residue on the quad flat non-leaded (QFN) could result in low reliability and failure in electrical conductivity tests. The tape residue would affect overall performance of the chips and contribute to low pass yield. The purpose of this paper is to present an in-depth study of tape residue and factors that may affect it.

An experiment using lead frame and tapes from three manufacturers with two types of die bond adhesives, namely, die attach film (DAF) and wafer back coating (WBC), was conducted. Copper (Cu) wire bonding and die bonding performances were measured in terms of process capability, stitch bond strength and die attach strength.

Results showed that no tape residue was observed on the thermoplastic adhesive-based lead frames manufactured by Hitachi after the de-taping process because of the tape’s thermoplastic adhesive properties.

This paper studies the occurrence of tape residue and a viable solution for it through the correct process optimization and combination of semiconductor manufacturing materials. Factors that may affect tape residue have also been studied and further research can be done to explore other options in the future as an alternate solution.

Die edge quality with its corresponding die strength are two important factors for excellent dicing quality especially for low-k wafers due to their weak mechanical properties and fragile structures. It is shown in past literatures that laser dicing or grooving does yield good dicing quality with the elimination of die mechanical properties. This is due to the excess heat energy that the die absorbs throughout the procedure. Within the internal structure, the mechanical properties of low-k wafers can be further enhanced by modification of the material. The purpose of this paper is to strengthen the mechanical properties of wafers through the heat-treatment process.

The methodology of this approach is by heat treating several low-k wafers that are scribed with different laser energy densities with different laser micromachining parameters, i.e. laser power, frequency, feed speed, defocus reading and single/multibeam setup. An Nd:YAG ultraviolet laser diode that is operating at 355 nm wavelength was used in this study. The die responses from each wafer are thoroughly visually inspected to identify any topside chipping and peeling. The laser grooving profile shape and deepest depth are analysed using a laser profiler, while the sidewalls are characterized by scanning electron microscopy (SEM) to detect cracks and voids. The mechanical strength of each wafer types then undergoes three-point bending test, and the performance data is analyzed using Weibull plot.

The result from the experiment shows that the standard wafers are most susceptible to physical defects as compared to the heat-treated wafers. There is improvement for heat-treated wafers in terms of die structural integrity and die strength performance, which revealed a 6% increase in single beam data group for wafers that is processed using high energy density laser output but remains the same for other laser grooving settings. Whereas for multibeam data group, all heat-treated wafer with different laser settings receives a slight increase at 4% in die strength.

Heat-treatment process can yield improved mechanical properties for laser grooved low-k wafers and thus provide better product reliability.

This paper aims to discuss the effects of ionic contaminations on the die surface of high lead flip chip ball grid array (FCBGA) package. Ionic contaminations from the flux residue, formed during the die attachment process, could affect the package long‐term performance.

Thus, the flux‐cleaning process was implemented and the cleanliness effect was evaluated. Cleaning experiments using a new water‐based solvent were carried out to investigate the flux‐cleaning efficiency. The test packages were then evaluated via ion chromatography (IC).

Ion chromatograms show that there are high levels of ionic elements detected prior to the cleaning process. After the cleaning process, the contamination levels reduced significantly.

The value of the work here is testing of the new environmental friendly water‐based MPC^® cleaning efficiency. The reduction of ionic contamination is thus reported.

The increased use recently of area‐array technology in electronic packaging has similarly increased the importance of predicting the thermal distribution of area‐array solder interconnection. As the interconnection technology for flip chip package is getting finer and smaller, it is extremely difficult to obtain the accurate values of thermal stresses by direct experimental measurements. Different types of solder bumps used for interconnection would also influence the thermal distribution within the package. Because the solder balls are too small for direct measurement of their stresses, finite element method (FEM) was used for obtaining the stresses instead.

This paper will discuss the results of the thermal stress distribution using numerical method via ABAQUS software. The variation of the thermal stress distribution with the temperature gradient model was evaluated to study the effects of the different material thermal conductivity of solder bumps used. A detailed 2D finite element model was constructed to perform 2D plain strain elastoplastic analysis to predict areas of high stress.

It is found that thermal distribution of solder bumps starts to propagate from the top region to the bottom region of the solder balls. Other than that, thermal stress effect increases in parallel with the increasing of the temperature. The simulation results shows that leaded solder balls, SnPb have higher maximum thermal stress level compared to lead‐free SAC solder balls.

The paper describes combination of stress with thermal loading correlation on a flip chip model. The work also shows how the different thermal conductivity on solder balls influences the thermal induced stress on the flip chip package.

This study explored the ramifications of COVID-19 on construction operations in Malaysia.

Following a detailed literature review, 37 ramifications are identified and divided into nine aspects. A self-designed survey is then employed to seek the perceptions of construction practitioners around the Klang Valley region regarding the significance of the ramifications. A total of 203 valid responses are subjected to statistical analyses to prioritise the ramifications.

All the potential ramifications are perceived to be significant, with the five utmost critical ramifications being rescheduling the project timeline, compliance with government SOP, delay in the handover project, compulsory COVID-19 test for all workers and the extra cost incurred to provide COVID-19 test for workers.

This study highlights the ramifications of COVID-19 on construction operations and deliberately informs construction organizations regarding the shortcomings of recent construction management. Besides, the insights suggested that industry practitioners devise corresponding strategies for project sustainability in future similar crises.

The findings serve as a valuable reference and are benign to industry professionals and researchers from developing nations, especially nations that share similar characteristics to Malaysia.

The surging entrance of new mobile payment merchants into the growing market has prompted the need for an in-depth understanding of loyalty formation to retain customers. This study examines customers' loyalty generation process in mobile payment services by exploring the serial effect of cognitive drivers (i.e. brand awareness, perceived quality, brand image, perceived value and layout) on affective response, satisfaction and loyalty.

A survey using self-administered questionnaires was conducted. The data was collected from 370 consumers who have experience using mobile payment services in Vietnam. The data were submitted to partial least square structural equation modeling (PLS-SEM) and artificial neural networks (ANN) analysis.

The results indicated that all the proposed cognitive drivers show significant impacts on affective response, which, in turn, translates into satisfaction and loyalty. The post-hoc analysis revealed enjoyment as the vital affective response in determining satisfaction. Moreover, the multigroup analysis indicated that the relationship between affective response and satisfaction is stronger for the female group. In addition, the ANN's nonlinear result revealed complementary insight into the importance of cognitive drivers.

The current study revealed both linear and nonlinear mechanisms that explicate the roles of cognitive drivers and affective responses in fostering loyalty toward mobile payment merchants. The findings add to the existing literature that emphasizes consumers' initial mobile payment adoption.