Number Of IOs Research Articles

Can a Combination of Convective and Magmatic Heat Transport in the Mantle Explain Io's Volcanic Pattern?

AbstractTidal dissipation makes Jupiter's moon Io the most volcanically active body in the solar system. Most of the heat generated in the interior is lost through volcanic activity. In this study, we aim to answer the questions: Can convection and melt migration in the mantle explain the spatial characteristics of Io's observed volcanic pattern? And, if so, what constraints does this place on the viscosity and thickness of the convective layer? We examine three different spatial characteristics of Io's volcanic activity: (i) The presence of global volcanism, (ii) the presence of large‐scale variations in Io's volcanic activity, and (iii) the number of Io's volcanic systems. Our study relies on the assumptions that melt in the mantle controls Io's global volcanism, that the large‐scale variations of Io's volcanic activity are caused by nonuniform tidal heating, and that the spatial density of volcanoes correlates with the spatial density of convective anomalies in the mantle. The results show that the observed small and large‐scale characteristics of Io's volcanic pattern can be explained by sublithospheric anomalies influenced and caused by convective flow. Solutions that allow for active volcanism and Io's specific large‐scale variations in volcanic activity range from a thick mantle of a high viscosity ( Pa s) to a thin asthenosphere of a low viscosity ( Pa s). Provided that Io's volcanoes are induced by convective anomalies in the mantle, we find that more than 80% of Io's internal heat is transported by magmatic processes and that Io's upper mantle needs to be thicker than 50 km.

Cost Analysis of Flip Chip Assembly Processes: Mass Reflow with Capillary Underfill and Thermocompression Bonding with Nonconductive Paste

Many factors affect the selection of the assembly and interconnect processes used to package a die. For example, the size of the die and package, the type of substrate, and the number of IOs all must be considered. In this paper, two processes are compared: a flip chip process using mass reflow with capillary underfill versus a flip chip thermocompression bonding process using nonconductive paste. Activity based cost modeling is used for the analysis. Both of the process flows are presented in detail, then multiple cost comparisons are presented. Examples of the variables that will change are package size, material cost, and equipment cost. In most cases, the bonding and material portions of the process flows are focused on rather than the entire assembly and substrate processes—this allows for a better analysis of particular details. Conclusions are drawn about which design scenarios are suitable for each process flow. Key cost drivers that may affect future cost comparisons as the technologies advance are also indicated.