RFIC Package Sidewall Shielding Without Antenna Resonance
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Solution Overview
Problem
Conventional RFIC packages face challenges in effectively shielding electro-magnetic interference (EMI) without degrading the performance of substrate antenna layers, particularly in new generation 5G antennas operating at millimeter wavelengths, where EMI shields extending to antenna layers can create resonance cavities and degrade antenna performance.
Innovation Solution
The implementation of a substrate sidewall partial shield that extends down the shared sidewalls of the IC die layer and substrate metallization layers, but not the substrate antenna layers, to provide EMI shielding while maintaining antenna performance by avoiding the creation of resonance cavities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an EMI shield extends down to the substrate antenna layers, then EMI shielding effectiveness is improved, but antenna performance deteriorates due to resonance cavity formation
Solution Approach 1:
The EMI shield is segmented into two distinct parts: a first EMI shield portion extending down to the substrate metallization layers, and a second EMI shield portion extending further to the substrate antenna layers. This segmentation allows the first portion to provide EMI shielding for the RFIC die while the second portion is selectively positioned to avoid creating resonance cavities that would degrade antenna performance.
Solution Approach 2:
Different regions of the EMI shield are designed with different extension depths based on local requirements. The region adjacent to the RFIC die receives full EMI shielding (first portion), while the region adjacent to the antenna elements receives no EMI shield extension (second portion omitted), preserving local antenna performance while maintaining overall EMI protection.
2Area of stationary object
If the substrate antenna layers are reduced in size for 5G millimeter wavelength operation, then device integration is improved, but antenna performance becomes more sensitive to EMI shield placement
Solution Approach 1:
The EMI shield structure is segmented to provide differentiated protection levels. The first EMI shield portion provides shielding for the RFIC die without extending into the antenna region, while the second portion is selectively added or omitted based on whether full shielding is needed. This allows compact antenna design while preventing harmful resonance effects.
Solution Approach 2:
The EMI shield configuration is locally optimized for different functional regions. In regions where RFIC dies are mounted, full EMI shielding is provided. In regions where antenna elements are located, the EMI shield is truncated to avoid creating resonance cavities. This local differentiation enables compact antenna design for 5G applications while maintaining performance.
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
This approach effectively shields the RFIC die from EMI interference without degrading the antenna performance, ensuring improved antenna performance even when substrate antenna layers are reduced in size, as seen in 5G antennas.
Implementation Method 1
an EMI shield. The EMI shield surrounds the IC die layer and extends down the shared sidewalls of the IC die layer and the substrate
Data Source
AI summary
Radio-frequency (RF) integrated circuit (IC) (RFIC) packages employing a substrate sidewall partial shield for electro-magnetic interference (EMI) shielding. A RFIC package includes an IC die layer that includes a RFIC die(s) mounted on a substrate that includes substrate metallization layers, a substrate core, and substrate antenna layers. The RFIC package includes an EMI shield surrounding the IC die layer and extending down shared sidewalls of the IC die layer and the substrate. The EMI shield extends down the sidewalls of the IC die layer and substrate metallization layers of the substrate to at least the interface between the substrate metallization layers and the substrate core, and without extending adjacent to the sidewall of the substrate antenna layers. In this manner, antenna performance of the antenna module may not be degraded, because extending the EMI shield down sidewalls of the substrate antenna layers can create a resonance cavity in the substrate.