A packaged RF amplifier device includes input and output leads and a transistor die. The transistor die includes a transistor with a drain-source capacitance below 0.1 picofarads per watt. The device also includes a conductive connection between the transistor output terminal and the output lead, and a baseband termination circuit between the transistor output terminal and a ground reference node. The baseband termination circuit presents a low impedance to signal energy at envelope frequencies and a high impedance to signal energy at RF frequencies. The baseband termination circuit includes an inductive element, a resistor, and a capacitor connected in series between the transistor output terminal and the ground reference node. Except for a minimal impedance transformation associated with the conductive connection, the device is unmatched between the transistor output terminal and the output lead by being devoid of impedance matching circuitry between the transistor output terminal and the output lead.

Example power amplifier chips and communication devices are described. One example power amplifier chip includes a package housing and a plurality of power amplifier dies. The plurality of power amplifier dies are packaged in the package housing, and each of the plurality of power amplifier dies includes at least one stage of power amplifier.

A high-frequency module includes a module substrate having main surfaces, one or more module components disposed on the main surface, a resin member covering the main surface, and a metal shield layer covering a top surface of each of the resin member and the one or more module components, and set to ground potential. A sub-module component, which is one of the one or more module components, has a sub-module substrate having main surfaces, a first circuit component disposed on the main surface, one or more second circuit components disposed on the main surface, a resin member covering the main surface, and a side surface shield layer covering a side surface of each of the resin member and the sub-module substrate, and set to the ground potential. An end surface on a top surface side of the side surface shield layer contacts the metal shield layer.

Radio frequency (RF) packages containing substrates having coefficient of thermal expansion (CTE) matched mount pads are disclosed, as are methods for fabricating RF packages and substrates. In embodiments, the RF package contains a high thermal performance substrate including a metallic base structure, which has a frontside facing a first RF power die and a first die attach region on the frontside of the base structure. A first CTE matched mount pad is bonded to the metallic base structure and covers the first die attach region. The first CTE mount pad has a CTE greater than the CTE of RF power die and less than the CTE of the metallic base structure. An electrically-conductive bonding material attaches the RF power die to the first CTE matched mount pad, while RF circuitry integrated into first RF power die is electrically coupled to the metallic base structure through the mount pad.

RF transistor amplifiers are provided that include a submount and an RF transistor amplifier die that is mounted on top of the submount. A multi-layer encapsulation is formed that at least partially covers the RF transistor amplifier die. The multi-layer encapsulation includes a first dielectric layer and a first conductive layer, where the first dielectric layer is between a top surface of the RF transistor amplifier die and the first conductive layer.

Package assemblies for improving heat dissipation of high-power components in microwave circuits are described. A laminate that includes microwave circuitry may have cut-outs that allow high-power components to be mounted directly on a heat slug below the laminate. Electrical connections to circuitry on the laminate may be made with wire bonds. The packaging allows more flexible design and tuning of packaged microwave circuitry.

Disclosed herein are IC structures, packages, and device assemblies with III-N transistors that include additional materials, referred to herein as “stressor materials,” which may be selectively provided over portions of polarization materials to locally increase or decrease the strain in the polarization material. Providing a compressive stressor material may decrease the tensile stress imposed by the polarization material on the underlying portion of the III-N semiconductor material, thereby decreasing the two-dimensional electron gas (2DEG) and increasing a threshold voltage of a transistor. On the other hand, providing a tensile stressor material may increase the tensile stress imposed by the polarization material, thereby increasing the 2DEG and decreasing the threshold voltage. Providing suitable stressor materials enables easier and more accurate control of threshold voltage compared to only relying on polarization material recess.

A transistor amplifier includes a group III-nitride based amplifier die including a gate terminal, a drain terminal, and a source terminal on a first surface of the amplifier die and an interconnect structure electrically bonded to the gate terminal, drain terminal and source terminal of the amplifier die on the first surface of the amplifier die and electrically bonded to an input path and output path of the transistor amplifier.

A radio-frequency module includes a multilayer substrate, a first semiconductor device, a second semiconductor device, and an anisotropic conductive resin component. The multilayer substrate includes a plurality of stacked layers, and has a first major face and a second major face. The first major face includes a first recess. The first semiconductor device is mounted over a bottom face of the first recess with the anisotropic conductive resin component interposed therebetween. The second semiconductor device is mounted over the first major face so as to overlie the first recess. The first semiconductor device is connected with a metallic via that extends through a portion of the multilayer substrate from the bottom face of the first recess to the second major face.

The present disclosure relates to a system in package having a chiplet with a first substrate and a first die deposed over the first substrate, a second die, a second substrate that the chiplet and the second die are deposed over, and a heatsink spreader deposed over the chiplet and the second die. Herein, the first substrate includes layered-cake shaped heatsink stanchions that are coupled to the first die, and the second substrate includes layered-cake shaped heatsink stanchions that are coupled to the chiplet and the second die. As such, heat generated by the first die can be dissipated by the heatsink stanchions within the first and second substrates, and heat generated by the second die can be dissipated by the heatsink stanchions within the second substrate. Furthermore, the heat generated by the first die and the second die can be dissipated by the heatsink spreader above them.