Electronic Package Shielding With Ferrite Air-Gap Structure
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Solution Overview
Problem
Conventional semiconductor packages with copper covers fail to provide adequate shielding against magnetic interference, especially for MRAM chips, with shielding performance less than −10 dB under low frequency conditions, and existing enhancements with magnetic conductive materials still fall short of the required −15 dB performance.
Innovation Solution
Incorporating a magnetic conductive member, such as ferrite, with an air gap between the cover and the semiconductor chip, and forming an air gap between the magnetic conductive member and the cover to enhance shielding, using an iron cover and adhesive layers to secure the structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a copper cover is used for shielding, then electrical quality is improved, but magnetic field shielding performance deteriorates (less than -10 dB under low frequency conditions)
Solution Approach 1:
The patent combines copper cover (for electrical shielding) with magnetic conductive material (for magnetic field shielding) to create a composite shielding structure. This resolves the contradiction by integrating materials with complementary properties: copper provides high electrical conductivity for EMI shielding, while the magnetic conductive material layer provides magnetic field shielding capability, achieving both electrical quality improvement and magnetic field protection.
Solution Approach 2:
The magnetic conductive material layer is nested on the inner side of the copper cover, creating a layered shielding structure. This nested configuration allows the copper cover to provide external electromagnetic shielding while the inner magnetic conductive layer specifically targets magnetic field interference, enabling dual-function shielding within a compact structure.
2Object-affected harmful factors
If magnetic conductive material is added to the copper cover, then magnetic field shielding is improved, but shielding performance still falls short (less than -15 dB required)
Solution Approach 1:
The patent introduces an air gap as an intermediary element between the magnetic conductive material layer and the copper cover. This air gap acts as a magnetic flux path mediator, enhancing the overall magnetic shielding effectiveness by creating a multi-path magnetic flux distribution that improves shielding performance to meet the -15 dB requirement.
Solution Approach 2:
The shielding structure is enhanced by combining three elements: copper cover, magnetic conductive material layer, and air gap. This triple-composite structure synergistically improves magnetic field shielding performance, where each component contributes its unique property: copper for electrical shielding, magnetic conductive material for magnetic flux guidance, and air gap for magnetic flux path optimization.
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 shielding performance is enhanced to greater than −15 dB, achieving at least 97% magnetic field shielding, and can reach up to −20 dB, meeting practical requirements.
Implementation Method 1
a magnetic conductive member disposed between the cover and the electronic element... the shielding performance is enhanced to greater than −15 dB, achieving at least 97% magnetic field shielding
Implementation Method 2
the magnetic conductive member and the cover are formed with an air gap therebetween... the shielding performance is enhanced to greater than −15 dB
Implementation Method 3
supporting legs 131 of the copper cover 13 are mounted on the packaging substrate 10 via the adhesive layer 14
Data Source
AI summary
An electronic package and a manufacturing method thereof are provided, in which a cover is disposed on a carrier structure having an electronic element, and the electronic element is covered by the cover. A magnetic conductive member is arranged between the cover and the electronic element, and an air gap is formed between the magnetic conductive member and the cover to enhance the shielding effect of the electronic package.