Embedded Ferromagnetic Shielding for Semiconductor EMI Control
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Solution Overview
Problem
Semiconductor devices are susceptible to electromagnetic interference (EMI), particularly low-frequency magnetic interference, which conventional conductive shielding layers fail to effectively address, and existing ferromagnetic shielding methods face issues like crystalline defects and delamination during deposition.
Innovation Solution
Embedding ferromagnetic film between two layers of encapsulant within the semiconductor package, combined with conductive pillars and a conductive shielding layer, to enhance magnetic interference absorption and prevent delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ferromagnetic film is applied using lamination process, then magnetic shielding effectiveness is improved, but delamination occurs at the interface between magnetic film and adjacent layers
Solution Approach 1:
An adhesive layer is introduced as an intermediary between the ferromagnetic film and the adjacent epoxy molding compound or metal shielding layer. This adhesive layer serves as a mediator that improves bonding and prevents delamination while maintaining the magnetic shielding effectiveness of the ferromagnetic film.
Solution Approach 2:
The patent uses composite material structure by combining ferromagnetic film with adhesive layers and encapsulant materials. This composite approach allows the system to simultaneously achieve magnetic shielding properties from the ferromagnetic film and improved adhesion from the adhesive layers, resolving the contradiction between shielding effectiveness and structural stability.
2Reliability
If magnetic film with high permeability is deposited using physical vapor deposition, then magnetic shielding capability is improved, but crystalline defects occur frequently
Solution Approach 1:
The patent changes the deposition parameters and material composition to achieve high magnetic permeability while reducing crystalline defects. By adjusting deposition conditions and selecting appropriate ferromagnetic materials, the system maintains effective magnetic shielding capability while improving film quality and reducing manufacturing defects.
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 embedded ferromagnetic shielding effectively reduces low-frequency magnetic interference and improves adhesion, enhancing the semiconductor device's performance and reliability by minimizing delamination issues.
Implementation Method 1
materials with a high magnetic permeability or ferrites are used to protect sensitive components
Implementation Method 2
Conductive shielding layers can be formed over semiconductor packages to reduce some interference
Data Source
AI summary
A semiconductor device has a substrate. A semiconductor die is disposed over the substrate. A first encapsulant is deposited over the semiconductor die. A ferromagnetic film is disposed over the first encapsulant. A second encapsulant is deposited over the ferromagnetic film. A shielding layer is optionally formed over the substrate, first encapsulant, and second encapsulant.