Electromagnetic Isolation Structure Using Conformal Coating and Faraday Cage

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Solution Overview

Problem

Conventional fabrication techniques struggle to produce high-density multi-chip modules with effective electromagnetic isolation, leading to issues like crosstalk and performance degradation due to RF interference, as semiconductor devices shrink and operating conditions become more demanding.

Innovation Solution

The integration of an electromagnetic shielding layer, a coating layer with a conductive layer, and the use of hollow spheres filled with inert gas or air to reduce the dielectric constant, forming a Faraday cage around integrated circuits to facilitate electromagnetic isolation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional approaches (via-fence enclosures, metal lids, metal cans) are used for electromagnetic isolation, then shielding effectiveness is improved, but device complexity and manufacturing complexity increase

Engineering Contradiction:

Improveelectromagnetic interferenceVSAvoidmanufacturing complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses a thin film coating layer deposited directly onto the integrated circuit substrate, replacing bulky conventional shielding structures like metal lids and via-fence enclosures. This thin film approach provides electromagnetic isolation while maintaining a compact form factor and simplifying the overall device structure.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent combines multiple functions into a single integrated structure: the coating layer serves both as an electromagnetic shielding layer and as part of the device's structural envelope. This merging eliminates the need for separate shielding components and their associated joining processes (brazing, soldering, welding, sealing).

Inventive Principle:

Principle #5Merging (Combining)

2Object-affected harmful factors

If conventional shielding structures (via-fence enclosures, metal lids) are used, then electromagnetic isolation is improved, but device size increases

Engineering Contradiction:

Improveelectromagnetic interferenceVSAvoiddevice size

Core Design Contradiction:

Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The patent employs a thin film coating layer that conformally coats the integrated circuit, providing electromagnetic shielding without the bulk of conventional structures. This thin film approach enables miniaturization while maintaining shielding effectiveness, which is critical for modern compact electronic devices.

Inventive Principle:

Principle #30Flexible shells and thin films

3Object-affected harmful factors

If conventional joining techniques (brazing, soldering, welding, sealing) are used to attach shielding structures, then shielding effectiveness is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveelectromagnetic interferenceVSAvoidmanufacturing complexity

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent integrates the electromagnetic shielding function directly into the device structure through a deposited coating layer, eliminating the need for separate shielding components that would require joining processes. This integration removes complex manufacturing steps such as brazing, soldering, welding, and sealing from the production workflow.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces mechanical joining processes (brazing, soldering, welding, sealing) with a deposition process where the coating layer is directly formed on the substrate. This substitution eliminates the need for complex mechanical attachment operations and their associated quality control requirements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach effectively reduces electromagnetic interference, enabling high-performance miniaturization of RFICs and other electronic systems, meeting isolation requirements of up to 150 dB while reducing manufacturing complexity and size.

Implementation Method 1

the conductive layer is formed to connect with the electromagnetic shielding layer, to facilitate electromagnetically isolating the integrated circuit

Methodology Applied

Scientific EffectFaraday cage: Faraday Cage

Implementation Method 2

the coating layer comprising a conformal coating and at least one hollow sphere, the sphere filled with at least one of an inert gas or air

Methodology Applied

Scientific EffectDielectric constant reduction: Dielectric Permittivity

Data Source

PatentUS10026701B1Electromagnetic isolation structure

Publication Date: 2018.07.17 NATIONAL TECHNOLOGY & ENGINEERING SOLUTIONS OF SANDIA LLC

AI summary

The various technologies presented herein relate to isolating an integrated circuit from electromagnetic radiation/interference. The integrated circuit can be encapsulated in a coating (e.g., a conformal coating). A conductive layer can be formed over the coating, where the conductive layer is deposited to connect with an electromagnetic shielding layer included in a substrate upon which the integrated circuit is located thereby forming a Faraday cage around the integrated circuit. Hollow spheres can be included in the coating to improve the dielectric constant of the coating. The conductive layer can be formed from at least one of metallic material or a polymer coating which includes conductive material. The integrated circuit can be utilized in conjunction with a heat sink and further, the integrated circuit can be of a flip chip configuration.