Flip-Chip Packaging of Low-Noise Metamorphic High Electron Mobility Transistors on Low-Cost Organic Substrate

Abstract

A 6-dimensional grand unified theory with the compact space having the topology of a real projective plane, i.e., a 2-sphere with opposite points identified, is considered. The space is locally flat except for two conical singularities where the curvature is concentrated. One supersymmetry is preserved in the effective 4d theory. The unified gauge symmetry, for example SU(5) , is broken only by the non-trivial global topology. In contrast to the Hosotani mechanism, no adjoint Wilson-line modulus associated with this breaking appears. Since, locally, SU(5) remains a good symmetry everywhere, no UV-sensitive threshold corrections arise and SU(5)-violating local operators are forbidden. Doublettriplet splitting can be addressed in the context of a 6d N = 2 super Yang-Mills theory with gauge group SU(6). If this symmetry is first broken to SU(5) at a fixed point and then further reduced to the standard model group in the above non-local way, the two light Higgs doublets of the MSSM are predicted by the group-theoretical and geometrical structure of the model.

Assessment of Thermal Impact on Performance of Metamorphic High-Electron-Mobility Transistors on Polymer Substrates Using Flip-Chip-on-Board Technology

“…To obtain good RF performance of the FCOB structure, the CPW transmission line with compensation design has been considered in Ref. 20. Then, the thick photoresist from TOK Company was patterned for the Au microbump electroplating.…”

“…[8][9][10][11][12][13][14][15][16] Additionally, the flip-chip-on-board (FCOB) technology is a very costeffective solution for high-frequency applications because it bypasses chip-level assembly, which makes it easier for further integration with other components in the system. [17][18][19][20][21] Therefore, such technology not only reduces RF loss but also saves material cost from the elimination of the chip level package. Table I lists the material properties of some conventional substrates for millimeter-wave applications.…”

“…19) The characteristic of the flip-chip-packaged HEMT device on the RO 3210 organic substrate with epoxy-based underfill injection has been reported up to W band in our previous work. 20) While previous research effort was devoted mostly to the electrical performance of the FCOB technology, the impact of the bonding temperature on the device performance after packaging has not been investigated.…”

“…To obtain good RF performance of the FCOB structure, the CPW transmission line with compensation design has been considered in Ref. 20.…”