Electromagnetic field effects on Υ\Upsilon-meson dissociation in PbPb collisions at LHC energies

We investigate the effect of the electromagnetic field generated in relativistic heavy-ion collisions on the dissociation of $\Upsilon$ mesons. The electromagnetic field is calculated using a simple model which characterizes the emerging quark-gluon plasma (QGP) by its conductivity only. A numerical estimate of the field strength experienced by $\Upsilon$ mesons embedded in the expanding QGP and its consequences on the $\Upsilon$ dissociation is made. The electromagnetic field effects prove to be negligible compared to the established strong-interaction suppression mechanisms.Comment: 7 pages, 4 figure

A numerical study on mitigation of flying dies in compression molding of microelectronic packages

Compression molding with liquid encapsulants is a crucial process in microelectronic packaging. Material properties of highly filled systems of reactive epoxy molding compounds depend on process conditions in a complex manner, such as shear-thinning behavior, which is superimposed by a time- and temperature-dependent conversion rate, both strongly affecting viscosity. The focus is set on forces exerted on individual dice during encapsulation in fan-out wafer-level packaging (FOWLP). The presented framework consists of an analytical approach to calculate the melt front velocity and simulations carried out to capture the nonlinear kinematics, chemorheology, and to extract forces exerted on individual dice. It offers separate evaluation of pressure and shear contributions for two cases, 0° and 45° between the dice' frontal area and the melt front. Process parameters, such as compression speed, thus cycle time, and process temperature, are determined to keep the forces on the dice below the critical level, where drag forces exceed adhesive forces. As a result, process parameters are determined to minimize flying dice and thereby maximize yield. The approach is easily transferable to arbitrary geometries and is therefore well suited to face the challenges that come with the current efforts toward the transition from FOWLP to larger substrates

Using fluidic simulation for parameter optimization in compression molding of microelectronic packages

Compression molding with liquid encapsulants is a crucial process in microelectronic packaging. Material properties of highly filled systems of reactive epoxy molding compounds (EMC) depend on process conditions in a complex manner, such as shear-thinning behavior superimposed by a time- and temperature-dependent conversion rate, both strongly affecting viscosity. The focus of the present work is set on forces exerted on individual dies during encapsulation in Fan-Out Wafer Level Packaging (FOWLP). The presented framework consists of an analytical approach to estimate the meltfront velocity and simulations carried out to capture the nonlinear kinematics. It offers separate evaluation of pressure and shear-contributions and allows to determine process parameters, such as compression speed and process temperature, to choose encapsulants and thermal-release tapes (TRT) to minimize flying dies