RF Semiconductor Package With Dual Absorption Layers for Channel Isolation
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Solution Overview
Problem
In RF semiconductor devices, undesired RF signal coupling between transmission channels leads to poor performance and potential failure due to signal reflection and scattering, which is not adequately addressed by existing mold compounds with low-loss properties.
Innovation Solution
The implementation of an RF semiconductor device with a dual-layer RF absorption layer arrangement, where the first and second layers have different real-parts of dielectric constants, strategically positioned to absorb RF signals scattered at varying angles, improving channel-to-channel isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If mold compound with low-loss properties is used to encapsulate the semiconductor die, then RF signal propagation is maintained without significant attenuation, but RF signal reflection and coupling between channels occurs leading to poor device performance
Solution Approach 1:
The RF absorption function is segmented into multiple layers with different dielectric properties. The patent introduces a first RF absorption layer with a first dielectric constant and a second RF absorption layer with a second dielectric constant, where the first dielectric constant is greater than the second dielectric constant. This segmentation allows different layers to handle different aspects of RF signal absorption, effectively reducing signal coupling while maintaining low attenuation.
Solution Approach 2:
Different regions of the RF absorption layer arrangement are assigned different dielectric constants to optimize local absorption characteristics. The first RF absorption layer with higher dielectric constant is positioned to address specific coupling paths, while the second RF absorption layer with lower dielectric constant handles other regions. This local differentiation of material properties enables targeted suppression of RF signal coupling between channels.
2Adaptability or versatility
If more functions are packed into RF semiconductor devices with small packages or multi-die RF devices are introduced, then device functionality and performance are improved, but interfering RF signal coupling between different RF transmission channels increases
Solution Approach 1:
The RF absorption layer arrangement acts as an intermediary between different RF transmission channels. Positioned between the semiconductor die and the mold compound, this intermediate structure absorbs stray RF signals and prevents them from coupling into adjacent channels. The dual-layer configuration with different dielectric constants provides graded absorption, effectively mediating the electromagnetic interaction between closely spaced RF channels in compact multi-functional devices.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances RF signal absorption and reduces unwanted coupling between transmission channels, thereby improving device performance and compliance with regulatory standards while maintaining cost-effectiveness.
Implementation Method 1
The first RF absorption layer has a first value of a real-part of a dielectric constant and the second RF absorption layer has a second value of a real-part of a dielectric constant, wherein the first value is different than the second value
Implementation Method 2
an elimination of an undesired radiation or signal is a crucial factor for reliable device performance
Data Source
AI summary
A radio frequency (RF) semiconductor device and a method to manufacture the RF semiconductor device. The RF semiconductor device includes a semiconductor die including a first surface and sidewalls vertical to the first surface. A mold compound encapsulates the sidewalls of the semiconductor die, wherein the mold compound extends beyond sidewalls of the semiconductor die in a first direction vertical to sidewalls of the semiconductor die. The RF semiconductor device further includes an RF absorption layer arrangement including a first RF absorption layer and a second RF absorption layer. The first RF absorption layer and the second RF absorption layer extend above the first surface of the semiconductor die in the first direction. The RF absorption layer arrangement includes a first side facing towards the semiconductor die.