JP-7855325-B2 - Amplifier module and system where the ground terminal is adjacent to the power amplifier die

JP7855325B2JP 7855325 B2JP7855325 B2JP 7855325B2JP-7855325-B2

Inventors

ジェフリーケビンジョーンズ
ケビンキム
フレークエグバートバンストラーテン
イブラヒムカリル

Assignees

エヌエックスピーユーエスエイインコーポレイテッド

Dates

Publication Date: 20260508
Application Date: 20211015
Priority Date: 20201229

Claims (14)

It is an amplifier module, A module substrate having a mounting surface, a signal transmission layer, a ground layer, and a first ground terminal pad on the mounting surface, A heat dissipation structure extending through the module substrate, having a first surface and a second surface, wherein the first surface is exposed on the mounting surface of the module substrate, A power transistor die having a ground contact, wherein the ground contact is coupled to the first surface of the heat dissipation structure, An encapsulation material that covers the mounting surface of the module substrate and the power transistor die, wherein the surface of the encapsulation material forms the contact surface of the amplifier module, An amplifier module comprising: a first ground terminal embedded in the encapsulating material, having a base end coupled to the first ground terminal pad and a tip exposed on the contact surface, and electrically coupled to the ground contact of the power transistor die through the first ground terminal pad, the ground layer of the module substrate, and the heat dissipation structure.
The amplifier module according to claim 1, wherein the heat dissipation structure comprises a conductive structure selected from a metal coin and a set of thermal vias.
The amplifier module according to claim 1, wherein the ground layer of the module substrate is in contact with the heat dissipation structure.
The amplifier module according to claim 1, wherein the first ground terminal is provided with a conductor pillar.
The first ground terminal is, The amplifier module according to claim 1, comprising an interposer terminal having a dielectric having a top surface and a bottom surface, and a conductive via extending between the top surface and the bottom surface of the dielectric.
The first ground terminal is, A first conductor pad located on the top surface of the dielectric and connected to the first end of the conductor via, the first conductor pad corresponding to the tip of the first ground terminal, The amplifier module according to claim 5, further comprising: a second conductor pad located on the bottom surface of the dielectric and connected to the second end of the conductor via, the second conductor pad corresponding to the base end of the first ground terminal.
The module board further comprises a signal terminal pad, a second ground terminal pad, and a third ground terminal pad on the mounting surface, wherein the signal terminal pad is electrically connected to either the input or output of the power transistor die through the signal transmission layer, and the second ground terminal pad and the third ground terminal pad are adjacent to the signal terminal pad. The aforementioned amplifier module is A signal terminal embedded within the aforementioned encapsulating material, having a base end coupled to the signal terminal pad and a tip exposed at the contact surface, A second ground terminal embedded within the aforementioned sealing material, having a base end coupled to the second ground terminal pad and a tip end exposed at the contact surface, A third ground terminal embedded within the aforementioned sealing material, further comprising a base end coupled to the third ground terminal pad and a tip end exposed at the contact surface, The amplifier module according to claim 1, wherein the signal terminal, the second ground terminal, and the third ground terminal form a ground-signal-ground terminal structure.
It is an amplifier system, A system substrate having a first mounting surface, a first signal transmission layer, a first ground layer, and a ground pad on the first mounting surface, wherein the ground pad is electrically coupled to the first ground layer, An amplifier module having a contact surface and a heat sink mounting surface, wherein the amplifier module is coupled to the system board such that the first mounting surface of the system board faces the contact surface of the amplifier module, and the amplifier module is A module substrate having a second mounting surface, a second signal transmission layer, a second ground layer, and a first ground terminal pad on the second mounting surface, A heat dissipation structure extending through the module substrate, having a first surface and a second surface, wherein the first surface is exposed on the second mounting surface of the module substrate, A power transistor die having a ground contact, wherein the ground contact is coupled to the first surface of the heat dissipation structure, An encapsulation material that covers the second mounting surface of the module substrate and the power transistor die, wherein the surface of the encapsulation material forms the contact surface of the amplifier module, An amplifier system further comprising: a first ground terminal embedded in the encapsulating material, having a base end coupled to the first ground terminal pad and a tip exposed on the contact surface, and electrically coupled to the ground contact of the power transistor die through the first ground terminal pad, the second ground layer of the module substrate, and the heat dissipation structure.
The amplifier system according to claim 8 , wherein the tip of the first ground terminal is coupled to the ground pad of the system board.
The module board further comprises a signal terminal pad, a second ground terminal pad, and a third ground terminal pad on the second mounting surface, wherein the signal terminal pad is electrically connected to either the input or output of the power transistor die through the second signal transmission layer, and the second ground terminal pad and the third ground terminal pad are adjacent to the signal terminal pad. The aforementioned amplifier module is A signal terminal embedded within the encapsulating material, having a base end coupled to the signal terminal pad and a tip exposed at the contact surface and electrically coupled to the first signal transmission layer of the system substrate, A second ground terminal embedded within the encapsulating material, having a base end coupled to the second ground terminal pad and a tip end exposed at the contact surface and electrically coupled to the first ground layer of the system substrate, A third ground terminal embedded in the encapsulating material, further comprising a base end coupled to the third ground terminal pad and a tip end exposed at the contact surface and electrically coupled to the first ground layer of the system substrate, The amplifier system according to claim 8 , wherein the signal terminal, the second ground terminal, and the third ground terminal form a ground-signal-ground terminal structure.
The amplifier system according to claim 8 , further comprising a heat sink bonded to the heat sink mounting surface.
A method for fabricating a power amplifier, A process for coupling a power transistor die to a heat dissipation structure extending through a module substrate, The module substrate has a first mounting surface, a first signal transmission layer, a first ground layer, and a first ground terminal pad on the first mounting surface. The first surface of the heat dissipation structure is exposed on the first mounting surface of the module substrate. The power transistor die has a ground contact coupled to the first surface of the heat dissipation structure, and the process is as follows: A step of connecting the base end of the first ground terminal to the first ground terminal pad of the module substrate, A method comprising the steps of covering the first mounting surface of the module substrate and the power transistor die with an encapsulation material to form an amplifier module, wherein the surface of the encapsulation material forms a contact surface of the amplifier module, the tip of the first ground terminal is exposed at the contact surface, and the first ground terminal is electrically coupled to the ground contact of the power transistor die through the first ground terminal pad, the first ground layer of the module substrate, and the heat dissipation structure.
The method according to claim 12, further comprising the step of coupling the amplifier module to a system board such that the second mounting surface of the system board faces the contact surface of the amplifier module, wherein the system board further comprises a second signal transmission layer, a second ground layer, and a ground pad on the second mounting surface, the ground pad being electrically coupled to the second ground layer, and the tip of the first ground terminal being coupled to the ground pad.
The amplifier module has a heat sink mounting surface opposite to the contact surface, and the method is The method according to claim 13 , further comprising the step of coupling the heatsink to the heatsink mounting surface of the amplifier module.

Description

The embodiments of the subject matter described herein generally relate to amplifier modules, and more particularly to amplifier modules comprising power transistor dies. Wireless communication systems utilize power amplifier modules to increase the power of radio frequency (RF) signals. A power amplifier module comprises a module board and an amplifier circuit coupled to the mounting surface of the module board. A typical module board has input and output (I/O) terminals on its bottom surface (i.e., the surface opposite the mounting surface) and may also have conductive signal routing structures extending through and across the module board between the I/O terminals and bond pads. Furthermore, one or more ground/heat dissipation structures may extend through the module board between the mounting surface and the bottom surface. Amplifier circuits often comprise a power transistor die containing one or more integrated power transistors with a bottom-side conductor ground layer. The bottom-side conductor ground layer of the power transistor die is directly connected to the surface of a ground/heat dissipation structure exposed on the mounting surface of the module substrate. In addition to dissipating heat from the power transistor die, the ground/heat dissipation structure may function to provide a ground reference to the power transistor die. An electrical connection is established between the bond pad on the module's mounting surface and the I/O bond pad on the power transistor die to transmit RF signals between the module substrate and the power transistor die. When the integrated power transistor is a field-effect transistor (FET), the die's input bond pad is connected to the FET's gate terminal, and the die's output bond pad is connected to the FET's drain terminal. The FET's source terminal is coupled through the die to the bottom-side conductor ground layer, which, as described above, is similarly connected to the module substrate's ground/heat dissipation structure. To integrate the above-described power amplifier module into a communication system, the module is typically coupled to the mounting surface of a printed circuit board (PCB). More specifically, the bottom surface of the module board is connected to the top surface of the system PCB so that the module's bottom-side signal I/O terminals are aligned with the corresponding signal I/O pads on the PCB mounting surface. In addition, the module board is connected to the system PCB so that the module's ground/heat dissipation structure contacts a PCB heat spreader extending through the system PCB. Therefore, the combination of the module's ground/heat dissipation structure and the system PCB heat spreader may perform a dual function: providing a thermal path to remove heat generated by the power transistor die and providing a ground reference for the power transistor die. During operation, the power transistor amplifies the input RF signal received through the input bond pad of the transistor die and transmits the amplified RF signal to the output bond pad of the transistor die. During this process, the heat generated by the power transistor die is dissipated through a ground/heat dissipation structure embedded in the module substrate and through the system PCB heat spreader. A ground reference is also provided through the ground/heat dissipation structure and the system PCB heat spreader. The above configuration works well for many applications. However, other applications require a different configuration where the thermal path for the heat generated by the power transistor die extends away from the system PCB rather than through it. However, such different structures introduce new challenges, including difficulties related to providing a sufficient ground reference to the power transistor die. A more complete understanding of the subject matter can be obtained by referring to the detailed description and claims, when considered in conjunction with the following drawings. Similar reference numbers refer to similar elements throughout the drawings. U.S. Patent No. 7,755,186 Schematic diagram of a Doherty power amplifier in a power amplifier module.A top view of a power amplification module embodying the Doherty power amplifier of Figure 1, according to an exemplary embodiment.A side view of the power amplifier module along line 3-3 in Figure 2.A cross-sectional side view along line 4-4 of an exemplary embodiment of the power amplifier module in Figure 2.A cross-sectional side view along line 4-4 of an exemplary embodiment of the power amplifier module in Figure 2.A cross-sectional side view along line 5-5 of an exemplary embodiment of the power amplifier module in Figure 2.A cross-sectional side view along line 5-5 of an exemplary embodiment of the power amplifier module in Figure 2.A cross-sectional side view along line 5-5 of an exemplary embodiment of the power amplifier module in Figure 2.A cross-sectional side view of an amplifier system com