Internal Shield Wall Layout for Compact RF Package Cross-Coupling
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Solution Overview
Problem
Existing microelectronic packages experience significant electromagnetic (EM) cross-coupling between signal paths, particularly in compact, high-power RF applications, which limits performance and efficiency.
Innovation Solution
The implementation of an internally-shielded microelectronic package with a shield structure composed of magnetically-permeable and electrically-conductive materials, positioned to reduce magnetic and electric cross-coupling between adjacent circuit elements, including a shield wall orthogonal to the substrate and grounded to further enhance shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If signal paths are placed in close proximity to reduce package size, then compact form factor is achieved, but EM cross-coupling between signal paths increases
Solution Approach 1:
A shield structure composed of magnetically-permeable material is positioned between adjacent signal paths to block electromagnetic fields. The shield acts as an intermediary that redirects EM energy away from sensitive signal paths, allowing compact packaging while preventing cross-coupling interference.
Solution Approach 2:
The shield structure utilizes magnetically-permeable composite materials that provide both magnetic shielding and structural support. These composite materials offer superior EM attenuation compared to conventional single-material shields, enabling effective cross-coupling reduction in compact package designs.
2Object-affected harmful factors
If shield structures are added to reduce EM cross-coupling, then shielding effectiveness improves, but manufacturing complexity increases
Solution Approach 1:
The shield structure is integrated with the leadframe assembly, combining multiple functions into a single component. The shield walls are formed as extensions of the leadframe structure itself, eliminating separate assembly steps and reducing manufacturing complexity while maintaining effective EM shielding.
Solution Approach 2:
The leadframe structure serves multiple functions: electrical interconnection, mechanical support, and electromagnetic shielding. By making the shield structure multi-functional as part of the leadframe, the patent avoids adding dedicated shielding components that would increase manufacturing complexity.
3Object-affected harmful factors
If magnetically-permeable shield material is used, then magnetic field shielding improves, but electrical conductivity decreases
Solution Approach 1:
The shield structure is positioned and dimensioned to provide magnetic shielding specifically in regions where cross-coupling occurs, rather than attempting to shield the entire package. This localized approach uses magnetically-permeable material only where needed, minimizing the impact on overall electrical conductivity while maintaining effective magnetic field blocking.
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
The internal shield structure effectively reduces EM cross-coupling, maintaining high performance and efficiency while being cost-effective to manufacture, particularly in compact, high-power RF applications.
Implementation Method 1
a magnetic shield layer having a magnetic permeability greater than that of the electrical shield layer
Implementation Method 2
an electrical shield layer... having an electrical conductivity less than that of the electrical shield layer
Data Source
Figure 1~2
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AI summary
Internally-shielded microelectronic packages having increased resistances to electromagnetic cross-coupling are disclosed, as are methods for fabricating such microelectronic packages. In embodiments, the internally-shielded microelectronic package includes a substrate having a frontside and a longitudinal axis. A first microelectronic device is mounted to the frontside of the substrate, while a second microelectronic device is further mounted to the frontside of the substrate and spaced from the first microelectronic device along the longitudinal axis. An internal shield structure includes or consists of a shield wall, which is positioned between the first and second microelectronic devices as taken along the longitudinal axis. The internal shield structure is at least partially composed of a magnetically-permeable material, which decreases electromagnetic cross-coupling between the first and second microelectronic devices during operation of the internally-shielded microelectronic package.