Multi-Layer Semiconductor Shielding for Broad-Frequency EMI
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices, particularly in high-frequency applications, are susceptible to electromagnetic interference (EMI), radio frequency interference (RFI), and low frequency magnetic interference, which existing shielding materials are ineffective in addressing.
Innovation Solution
A multi-layer shielding structure comprising a combination of protective layers, soft ferromagnetic layers, and high conductivity metals is applied over semiconductor devices to shield against both high and low frequency interferences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-layer shielding structure is used, then the structure is simple and easy to manufacture, but it cannot effectively shield against both high and low frequency interferences
Solution Approach 1:
The shielding structure is segmented into multiple functional layers, each designed to address specific interference frequencies and provide particular protective functions. The soft ferromagnetic layer targets low frequency magnetic fields, the high conductivity metal layer targets high frequency electromagnetic interference, and the protective layers provide mechanical protection. This segmentation allows each layer to be optimized for its specific function while maintaining a relatively simple manufacturing process through sequential deposition.
Solution Approach 2:
The patent employs a composite multi-layer structure combining materials with different electromagnetic and mechanical properties. The soft ferromagnetic material provides high magnetic permeability for low frequency shielding, the high conductivity metal provides electrical conductivity for high frequency shielding, and the protective materials provide mechanical strength and oxidation resistance. This composite approach enables broad-spectrum interference shielding while maintaining manufacturability through established deposition techniques.
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 shielding structure effectively isolates and blocks both high and low frequency interferences, protecting sensitive semiconductor components from electromagnetic noise and magnetic fields.
Implementation Method 1
A multi-layer shielding structure comprising a combination of protective layers, soft ferromagnetic layers, and high conductivity metals is applied over semiconductor devices to shield against both high and low frequency interferences
Implementation Method 2
A high frequency shield can be made with conductive material coating, such as silver (Ag) or copper (Cu). However, most shielding materials are ineffective for low frequency interference, particularly from low frequency magnetic fields
Data Source
AI summary
A semiconductor device has a substrate and electrical components disposed over the substrate. An encapsulant is disposed over the substrate and electrical components. A multi-layer shielding structure is formed over the encapsulant. The multi-layer shielding structure has a first layer of ferromagnetic material and second layer of a protective layer or conductive layer. The ferromagnetic material can be iron, nickel, nickel iron alloy, iron silicon alloy, silicon steel, nickel iron molybdenum alloy, nickel iron molybdenum copper alloy, iron silicon aluminum alloy, nickel zinc, manganese zinc, other ferrites, amorphous magnetic alloy, amorphous metal alloy, or nanocrystalline alloy. The first layer can be a single, homogeneous material. The protective layer can be stainless steel, tantalum, molybdenum, titanium, nickel, or chromium. The conductive layer can be copper, silver, gold, or aluminum. The multi-layer shielding structure protects the electrical components from low frequency and high frequency interference.