EMI Shielding via Selective Metal Coating on Insulating Housing
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Solution Overview
Problem
Existing methods for attenuating electromagnetic interference (EMI) in electrical devices are laborious and expensive, requiring large metal containers that occupy more space than necessary, making them inefficient for variously shaped and dimensioned packages.
Innovation Solution
A shielded electronic package comprising a semiconductor device within an insulating housing coated with a metal layer, except for areas adjacent to connective structures, which are left uncovered to prevent short circuits and minimize space occupation, along with a method of manufacturing this package by forming an insulating housing around the semiconductor device and applying a metal coating using techniques like physical vapor deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal container (can) is used to shield electronic components from EMI, then EMI attenuation is achieved, but the device occupies more space and the manufacturing process becomes laborious and expensive
Solution Approach 1:
The patent divides the shielding structure into segments: an insulating housing that encloses the semiconductor device and a metal coating that partially covers the housing. This segmentation allows the shielding function to be distributed across different materials and structures, reducing the need for a single large metal container while maintaining EMI attenuation effectiveness.
Solution Approach 2:
The metal coating is applied selectively to specific portions of the insulating housing rather than covering the entire structure. The coating covers the top surface and extends down the sides, but stops before the connective structures to prevent short circuits. This local application of metal provides EMI shielding where most needed while minimizing space occupation and material usage.
2Object-affected harmful factors
If a metal container (can) is used to shield electronic components from EMI, then EMI attenuation is achieved, but the manufacturing process becomes laborious and expensive
Solution Approach 1:
The patent combines multiple functions into integrated structures: the insulating housing serves both as mechanical protection and as a substrate for the metal coating, while the metal coating provides both EMI shielding and a reflective surface. The connective structures are integrated directly into the housing, eliminating separate mounting steps. This merging reduces manufacturing complexity compared to assembling separate metal can components.
Solution Approach 2:
The patent replaces the mechanical assembly process of traditional metal cans (stamping, bending, soldering frames and tops) with a more streamlined process: forming an insulating housing and applying a metal coating through vapor deposition or similar techniques. This substitution eliminates labor-intensive metal forming and assembly operations while achieving the same shielding function.
3Object-affected harmful factors
If the metal coating covers all portions of the insulating housing, then EMI shielding is maximized, but short circuits may occur at connective structures
Solution Approach 1:
The metal coating is applied with local quality variation: it covers the top surface and upper portions of the housing where EMI shielding is most critical, but deliberately stops before reaching the connective structures at the bottom. This creates different functional zones on the housing surface, providing maximum shielding where needed while maintaining electrical connectivity where required.
Solution Approach 2:
The insulating housing acts as an intermediary between the metal coating and the connective structures. The housing provides electrical isolation, allowing the metal coating to be positioned close to the connective structures without causing short circuits. This intermediary enables the coating to extend further down the housing sides while maintaining reliable electrical connectivity.
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
This solution effectively reduces EMI while being cost-effective and space-efficient, allowing for easier integration into smaller devices by selectively coating the housing to avoid short circuits and maintain connectivity.
Implementation Method 1
one or more of the electronic components are placed inside of metal container (e.g., a 'can') that forms a Faraday shield around the component
Implementation Method 2
applying a metal coating using techniques like physical vapor deposition
Data Source
AI summary
A shielded electronic package, comprising a semiconductor device, an insulating housing surrounding the semiconductor device and a metal coating on the insulating housing. The metal coating covers all but those portions of the insulating housing that are adjacent to connective structures on one or more mounting sides of the insulating housing.