Integrated EMI Shield Structure for Low-Profile Semiconductor Modules
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Solution Overview
Problem
Conventional electromagnetic interference (EMI) shielding methods for semiconductor devices, such as using a grounded metal enclosure, are costly, inflexible, and increase device size and weight, which is undesirable in modern RF communication systems.
Innovation Solution
A packaged semiconductor module with an integrated EMI shield is created by using a substrate with a ground plane, conductive posts, and a conductive layer on the mold compound, where the conductive posts extend from the bond pad to the conductive layer in a direction perpendicular to the substrate surface, forming a robust and flexible EMI shield with minimal size and weight addition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a grounded metal enclosure is used for EMI shielding, then EMI protection is improved, but device size and weight increase
Solution Approach 1:
The patent divides the EMI shielding function into multiple discrete conductive posts distributed around the RF device, replacing the single monolithic metal enclosure. Each post acts as an independent shielding element, collectively providing EMI protection while minimizing overall structure size and weight.
Solution Approach 2:
The patent uses thin conductive posts and conductive layers instead of thick metal enclosure walls. The conductive posts extend through the substrate and are connected to ground planes, creating effective EMI shielding with minimal material thickness, thereby reducing weight while maintaining protection.
2Object-affected harmful factors
If a grounded metal enclosure is used for EMI shielding, then EMI protection is improved, but manufacturing cost increases
Solution Approach 1:
The patent combines the EMI shielding function with existing structural elements of the device package, specifically the substrate and its ground planes. The conductive posts are integrated into the substrate structure, and the shielding function is merged with the mechanical support structure, eliminating the need for separate metal enclosure components and reducing manufacturing complexity.
Solution Approach 2:
The substrate serves multiple functions: it provides mechanical support, electrical interconnection, and EMI shielding. The ground planes on the substrate serve both as electrical reference planes for RF circuits and as part of the EMI shielding system, eliminating the need for dedicated shielding structures and reducing overall manufacturing cost.
3Object-affected harmful factors
If a grounded metal enclosure is used for EMI shielding, then EMI protection is improved, but design flexibility decreases
Solution Approach 1:
The distributed conductive posts can be selectively placed and configured based on specific design requirements. Different numbers, positions, and configurations of posts can be used for different RF devices or applications, allowing high design flexibility while maintaining EMI protection. The modular nature of individual posts enables easy adaptation to various package sizes and device layouts.
4Object-affected harmful factors
If a grounded metal enclosure is used for EMI shielding, then EMI protection is improved, but device footprint increases
Solution Approach 1:
The conductive posts and conductive layers create an effective EMI shielding structure with minimal footprint. The posts extend vertically through the substrate thickness rather than requiring lateral space, and the conductive layers are deposited as thin films on the substrate surface, maintaining compact device dimensions while providing comprehensive EMI protection.
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 solution provides effective EMI shielding with high design flexibility and reduced manufacturing costs, achieving inter/intra-module isolation and low package profile, which was not possible with conventional technologies.
Implementation Method 1
the conductive post, the conductive layer, and the ground plane together forming the integrated electromagnetic interference shield
Implementation Method 2
a conductive post disposed on a side of the electronic device, the conductive post extending from the bond pad and at least partially through the mold compound
Data Source
AI summary
A packaged semiconductor module comprises a substrate having a ground plane, an electronic device mounted on a surface of the substrate, a bond pad disposed on the surface of the substrate and electrically connected to the ground plane, a mold compound covering the electronic device, a conductive post disposed on a side of the electronic device, the conductive post extending from the bond pad and at least partially through the mold compound, and a conductive layer disposed on the mold compound and electrically coupled to the conductive post and to the ground plane, the conductive post, the conductive layer, and the ground plane together forming the integrated electromagnetic interference shield, the conductive post extending from the bond pad to the conductive layer in a direction perpendicular to a plane defined by the surface of the substrate.