A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier; and a first circuit component. The power amplifier includes: a first amplifying element; a second amplifying element; and an output transformer that includes a primary coil and a secondary coil. An end of the primary coil is connected to an output terminal of the first amplifying element, another end of the primary coil is connected to an output terminal of the second amplifying element, an end of the secondary coil is connected to an output terminal of the power amplifier, the first amplifying element and the second amplifying element are disposed on the first principal surface, and the first circuit component is disposed on the second principal surface.

This disclosure relates to a transmission line for high performance radio frequency (RF) applications. One such transmission line can include a bonding layer configured to receive an RF signal, a barrier layer, a diffusion barrier layer, and a conductive layer proximate to the diffusion barrier layer. The diffusion barrier layer can have a thickness that allows a received RF signal to penetrate the diffusion barrier layer to the conductive layer. In certain implementations, the diffusion barrier layer can be nickel. In some of these implementations, the transmission line can include a gold bonding layer, a palladium barrier layer, and a nickel diffusion barrier layer.

A semiconductor device that includes a bipolar transistor, wherein a third opening, through which a pillar bump and a second wiring line, which is electrically connected to an emitter layer, contact each other, is shifted in a longitudinal direction of the emitter layer away from a position at which the third opening would be directly above the emitter layer. The third opening is arranged, with respect to the emitter layer, such that an end portion of the emitter layer in the longitudinal direction of the emitter layer and the edge of the opening of the third opening are substantially aligned with each other.

A circuit element is formed on a substrate made of a compound semiconductor. A bonding pad is disposed on the circuit element so as to at least partially overlap the circuit element. The bonding pad includes a first metal film and a second metal film formed on the first metal film. A metal material of the second metal film has a higher Young's modulus than a metal material of the first metal film.

A semiconductor device includes an HBT; emitter wiring which is connected to an emitter electrode of the HBT and covers the HBT; a passivation film having an opening on the HBT in plan view; a UBM layer which is connected to the emitter wiring through the opening and made of a refractory metal with a thickness of 300 nm or more; and a pillar bump which is arranged on the UBM layer and includes a metal post and a solder layer. The UBM layer serves as a stress relaxation layer, thereby relaxing stress on the HBT due to a difference in thermal expansion coefficient between a GaAs-based material of each layer constituting the HBT and the pillar bump.

A semiconductor chip has a first transistor that amplifies a first signal and outputs a second signal, a second transistor that amplifies the second signal and outputs a third signal, and a semiconductor substrate having a main surface parallel to a plane defined by first and second directions and which has the first and second transistors formed thereon. The main surface has thereon a first bump connected to a collector or drain of the first transistor, a second bump connected to an emitter or source of the first transistor, a third bump connected to a collector or drain of the second transistor, and a fourth bump connected to an emitter or source of the second transistor. The first bump is circular, the second through fourth bumps are rectangular or oval, and the area of each of the second through fourth bumps is larger than that of the first bump.

Two transistor rows are arranged on or in a substrate. Each of the two transistor rows is configured by a plurality of transistors aligned in a first direction, and the two transistor rows are arranged at an interval in a second direction orthogonal to the first direction. A first wiring is arranged between the two transistor rows when seen from above. The first wiring is connected to collectors or drains of the plurality of transistors in the two transistor rows. The first bump overlaps with the first wiring when seen from above, is arranged between the two transistor rows, and is connected to the first wiring.

A high frequency module includes a transmission power amplifier, a bump electrode connected to the transmission power amplifier, and a mounting board on which the transmission power amplifier is mounted, wherein the mounting board includes a via conductor having an elongated shape in the plan view of the mounting board, a board main part placed outside the via conductor, and an insulating part placed inside the via conductor, and the bump electrode and the via conductor are connected while at least partially overlapping each other in the foregoing plan view, and the board main part and the insulating part are each composed of an insulating material of the same kind.

This disclosure relates to a radio frequency (RF) transmission line for high performance RF applications. The RF transmission line includes a bonding layer having a bonding surface and configured to receive an RF signal, a barrier layer proximate the bonding layer, a diffusion barrier layer proximate the bonding layer and configured to prevent contaminant from entering the bonding layer, and a conductive layer proximate the diffusion barrier layer. The diffusion barrier layer has a thickness that allows the received RF signal to penetrate the diffusion barrier layer to the conductive layer. The diffusion barrier layer can be a nickel layer.

One aspect of this disclosure is a power amplifier system that includes a control interface, a power amplifier, a passive component on a same die as the power amplifier, and a bias circuit on a different die than the power amplifier. The control interface can operate as a serial interface or as a general purpose input/output interface. The power amplifier can be controllable based at least partly on an output signal from the control interface. The bias circuit can generate a bias signal based at least partly on an indication of the electrical property of the passive component. Other embodiments of the system are provided along with related methods and components thereof.