Multi-Layer EMI Shield for Semiconductor Packages
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Solution Overview
Problem
Semiconductor devices face electromagnetic interference (EMI) issues due to higher clock speeds and smaller sizes, which traditional metal casings fail to adequately address, especially at lower frequencies, and these solutions increase manufacturing and product costs.
Innovation Solution
A semiconductor device package incorporating a shield layer with a combination of electrically conductive and magnetically permeable layers, where the electrically conductive layer is interposed between two magnetically permeable layers, providing enhanced EMI shielding without the need for a thick, single shielding layer, thus reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal casing or housing is used to shield semiconductor devices, then electromagnetic interference is reduced, but manufacturing and product costs increase
Solution Approach 1:
The patent applies composite materials by combining multiple layers with different properties (conductive layer, magnetically permeable layer, and dielectric layer) to create a shield structure that achieves superior EMI shielding performance while reducing overall thickness and cost compared to traditional solid metal casings. Each layer contributes specific functionality: the conductive layer handles high-frequency EMI, the magnetically permeable layer addresses low-frequency EMI, and the dielectric layer provides structural support and electrical isolation.
Solution Approach 2:
The patent segments the shielding function into multiple distinct layers, each optimized for specific frequency ranges and shielding mechanisms. This segmentation allows the shield to address both high-frequency and low-frequency EMI effectively while using thinner individual layers, reducing total material usage and manufacturing cost compared to a single thick metal casing.
2Object-affected harmful factors
If a metal casing or housing is used to shield semiconductor devices, then electromagnetic interference is reduced, but the thickness of the shielding layer increases
Solution Approach 1:
The composite multi-layer structure achieves effective EMI shielding at reduced thickness by leveraging the complementary shielding mechanisms of different materials. The conductive layer provides reflection and absorption for high-frequency EMI, while the magnetically permeable layer provides absorption for low-frequency EMI, allowing the overall shield to be thinner than a single metal casing would require.
Solution Approach 2:
Each layer in the shield structure has locally optimized properties tailored to specific shielding requirements. The conductive layer is optimized for electrical conductivity to handle high-frequency EMI, the magnetically permeable layer is optimized for magnetic permeability to handle low-frequency EMI, and the dielectric layer provides appropriate thickness and mechanical support, creating a locally optimized multi-functional structure.
3Ease of manufacture
If traditional single-layer shielding is used, then manufacturing is simpler, but shielding performance at low frequencies is insufficient
Solution Approach 1:
The patent introduces a magnetically permeable layer specifically designed to address low-frequency EMI shielding deficiencies of traditional single-layer conductive shields. This layer adds magnetic absorption capability that complements the electrical conduction-based shielding, creating a composite structure that maintains manufacturing feasibility while significantly improving low-frequency shielding 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
The multi-layer EMI shield effectively reduces electromagnetic interference at low frequencies, improving shielding performance while minimizing the overall thickness and cost of the shielding layer, making it more efficient than traditional single-layer solutions.
Implementation Method 1
When electromagnetic emissions from an interior of the package strike an inner surface of the casing, at least a portion of these emissions can be electrically shorted, thereby reducing the level of emissions that can pass through the casing
Implementation Method 2
a first magnetically permeable layer disposed over the package body, a first electrically conductive layer disposed over the first magnetically permeable layer, and a second magnetically permeable layer disposed over the first electrically conductive layer
Data Source
AI summary
A semiconductor device package includes: (1) a carrier; (2) an electronic component disposed over a top surface of the carrier; (3) a package body disposed over the top surface of the carrier and covering the electronic component; and (4) a shield layer, including a first magnetically permeable layer disposed over the package body, a first electrically conductive layer disposed over the first magnetically permeable layer, and a second magnetically permeable layer disposed over the first electrically conductive layer. The first electrically conductive layer is interposed between the first magnetically permeable layer and the second magnetically permeable layer. A permeability of the first electrically conductive layer is different from a permeability of the first magnetically permeable layer and a permeability of the second magnetically permeable layer.