Semiconductor Packaging Shielding Layers for EMI
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Solution Overview
Problem
Current electromagnetic shielding solutions for semiconductor packaging structures are inadequate in effectively addressing electromagnetic interference (EMI) due to issues with uneven thickness and poor edge coverage of shielding layers, leading to incomplete shielding and reduced shielding effectiveness.
Innovation Solution
A packaging structure with a first shielding layer covering the non-functional and sidewall surfaces of semiconductor chips, and a second shielding layer fully covering the first shielding layer, both having ellipsoidal shapes to ensure uniform coverage and improved edge coverage, along with a bottom shielding layer covering the functional surface to prevent EMI entry from the bottom.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a magnetic field shielding layer is provided on the semiconductor packaging structure, then electromagnetic interference between chips is shielded, but the shielding effect is insufficient due to uneven thickness and poor edge coverage
Solution Approach 1:
The shielding structure is divided into multiple independent shielding layers (first shielding layer, second shielding layer, and optional third shielding layer) that can be formed separately and stacked. Each layer contributes to the overall shielding effect, and the segmentation allows each layer to be optimized independently for coverage and thickness uniformity, resolving the issue of poor edge coverage in single-layer structures
Solution Approach 2:
The shielding layers are arranged in a nested configuration where the first shielding layer is positioned at a lower level, the second shielding layer is positioned at a higher level covering portions of the first layer, and optionally a third shielding layer provides additional coverage. This nested arrangement ensures comprehensive edge coverage and creates overlapping shielding zones that enhance overall shielding effectiveness while maintaining thickness uniformity
2Object-affected harmful factors
If shielding layers are added to cover all surfaces of semiconductor chips, then comprehensive electromagnetic shielding is achieved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
Each shielding layer is designed with specific local coverage characteristics - the first shielding layer covers certain surfaces, the second shielding layer covers other surfaces and portions of the first layer, and the third shielding layer (when present) provides additional localized coverage. This local quality approach ensures that each area of the chip receives appropriate shielding without requiring uniform complex structures everywhere, thus reducing overall device complexity while maintaining comprehensive shielding
Solution Approach 2:
The shielding structure transitions from a single-layer two-dimensional coverage to a multi-layer three-dimensional nested configuration. By adding the vertical dimension with stacked layers at different heights, the patent achieves comprehensive surface coverage and edge protection without requiring each individual layer to be overly complex, as the dimensional stacking naturally provides the necessary coverage overlap
3Ease of manufacture
If existing single-layer shielding structures are used, then the manufacturing process is simple, but the shielding effectiveness is reduced due to incomplete coverage
Solution Approach 1:
The first shielding layer is formed preliminarily on the semiconductor chip surfaces before the second shielding layer is applied. This preliminary action establishes a base shielding structure that can be subsequently enhanced by additional layers. The preliminary formation of the first layer allows for systematic building of the shielding structure, maintaining manufacturing simplicity while enabling comprehensive coverage through subsequent layers
Solution Approach 2:
The shielding structure employs composite construction with multiple shielding layers made of magnetically conductive materials, where each layer contributes different shielding characteristics. The composite multi-layer structure combines the advantages of each individual layer to achieve superior overall shielding effectiveness compared to single-layer structures, while the modular composite approach maintains ease of manufacture through standardized layer formation processes
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 integrated shielding solution provides comprehensive and intact shielding, enhancing the electromagnetic shielding effect by preventing EMI entry from all directions and improving production efficiency through mass production capabilities.
Implementation Method 1
a first shielding layer and a second shielding layer disposed between a semiconductor chip of the plurality of semiconductor chips and the encapsulation layer. The first shielding layer covers the non-functional surface and a sidewall surface of the semiconductor chip
Implementation Method 2
a bottom shielding layer formed on the functional surface of a semiconductor chip of the plurality of semiconductor chips. The bottom shielding layer covers the entire functional surface of the semiconductor chip
Data Source
AI summary
Packaging structure and formation method are provided. The packaging structure includes a pre-encapsulation panel, which includes an encapsulation layer containing a plurality of semiconductor chips. Each semiconductor chip includes a functional surface and a non-functional surface opposite to the functional surface. A plurality of pads are formed on the functional surface, and the encapsulation layer exposes the plurality of pads. The packaging structure also includes a first shielding layer and a second shielding layer disposed between a semiconductor chip and the encapsulation layer. The first shielding layer covers the non-functional surface and a sidewall surface of the semiconductor chip. The second shielding layer is disposed between the first shielding layer and the encapsulation layer and fully covers a surface of the first shielding layer. Further, the packaging structure includes an external contact structure disposed on a back side of the pre-encapsulation panel and connected to a pad.