We study how to solder two Siegel chiral bosons into one scalar field in a gravitational background. Permanent address: Instituto de F́ısica, Universidade Federal do Rio de Janeiro, Brasil [email protected] [email protected]

JULY 2012 50 High-temperature solder alloys are extensively used in dieattach, power semiconductor, and optical device packaging, flip-chip packaging, etc. Current industry standard solders for these applications are mainly high-lead solders (90–97 wt-% Pb) and gold-based eutectic solder alloys such as the 80Au20Sn solder. The die-attach process involves connecting the silicon die or chips to a...

Brazed components play an essential role in consistent joining techniques. The brazing process is characterized by low process temperatures and fast processing times, compared to welding techniques. Beside the resulting low manufacturing costs, brazing can join dissimilar materials, e.g. metals and ceramics. Consequently, brazing provides potential for many industrial applications like the prod...

Results: The operating frequency of our radio module is 38GHz and the transition is matched to 5 0 9 . A substrate thickness of 1 7 0 p was chosen which needs a line width of 3 6 3 ~ for the microstrip and coplanar line. The slot width is 3 1 ~ . The via holes are processed with a CO, laser and have diameters of 2 6 0 ~ on the top side and 1 8 0 2 3 0 ~ on the back side. These via holes have to...

Abstract At present, Sn-3.0Ag-0.5Cu (SAC305) solder is one of the commonly used lead-free solders, and copper-clad laminate PCB substrate. SAC copper substrate mainly generate two intermetallic compounds (IMCs) Cu6Sn5 Cu3Sn during soldering process. Based on first principles, this paper analyzes formation difficulty kinds IMCs generated in soldering, failure mechanism Sn/IMC IMC/Cu interfaces. ...