Optical Sensor EMI Shield Structure for Crosstalk and Leakage Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional EMI shields for optical sensors face challenges such as increased component and assembly costs, larger footprints due to rounded corners, and reduced effectiveness against higher frequency EM waves, along with internal crosstalk and gaps in multi-can shielding, and insufficient performance in thin packaging.

Innovation Solution

The use of localized conductive envelopments formed by EMI shields around electrical components, with protrusions and apertures, and integrated into device packaging, providing effective shielding while reducing material and assembly costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple metal cans are used to reduce footprint, then the footprint of the EMI shield is reduced, but gaps are introduced through which EM waves may leak

Engineering Contradiction:
Improvefootprint of EMI shieldVSAvoidEM wave leakage
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent merges multiple separate EMI shielding functions into a single integrated EMI shield structure with multiple chambers. Instead of using multiple separate metal cans that create gaps at interfaces, the invention provides one continuous conductive envelope with internal partitions that separates different components while maintaining overall shielding integrity and preventing EM wave leakage.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If conventional stamping fabrication techniques are used, then metal cans can be fabricated, but corners must have wide radius which increases footprint

Engineering Contradiction:
Improvefabrication of metal cansVSAvoidfootprint of EMI shield
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

The patent changes the geometric parameters of the EMI shield by incorporating sharp corners and right-angle features that are impossible to achieve with conventional stamping fabrication. This allows the shield to achieve minimal footprint without the need for rounded corners, thereby reducing the overall area occupied by the shielding structure.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If EMI shield is introduced into packaging of optical sensor, then EMI shielding is provided, but internal EMI crosstalk between electrical components within the same EMI shield occurs

Engineering Contradiction:
Improveexternal EMI shieldingVSAvoidinternal EMI crosstalk
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent segments the internal space of the EMI shield into multiple separate chambers using internal partitions or walls. Each electrical component is housed in its own isolated chamber, preventing electromagnetic interference between components while the outer EMI shield provides protection against external electromagnetic fields.

Inventive Principle:
Principle #1Segmentation

4Object-generated harmful factors

If multiple EMI shields are used to isolate electrical components, then internal EMI crosstalk is reduced, but material costs and assembly complexity increase

Engineering Contradiction:
Improveinternal EMI crosstalkVSAvoidnumber of EMI shields
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines multiple EMI shielding functions into a single integrated structure that provides both external shielding and internal component isolation. The EMI shield serves dual purposes: protecting against external electromagnetic interference while simultaneously separating internal components through integrated partitions, thereby eliminating the need for multiple separate shields.

Inventive Principle:
Principle #5Merging (Combining)

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

Enhances EMI shielding performance, reduces material costs, and optimizes space efficiency by using EMI shields as both shielding and spacers, minimizing internal interference and leakage.

Implementation Method 1

EMI shielding creates a Faraday cage effect which attenuates radiation of electromagnetic (EM) waves

Methodology Applied
Scientific EffectFaraday cage effect: Faraday Cage

Implementation Method 2

a lens coupled to the first EMI shield, wherein the lens is positioned above the first electrical component, and wherein the lens is substantially aligned with the first aperture

Methodology Applied
Scientific EffectLens focusing: Lens

Data Source

PatentEP4665105A1Methods, systems, and apparatuses for electromagnetic interference (EMI) shielding in optical sensors
Publication Date: 2025.12.17 STMICROELECTRONICS INT NV
  • EP4665105A1 patent drawingFigure 1
  • EP4665105A1 patent drawingFigure 2A~2B
  • EP4665105A1 patent drawingFigure 3

AI summary

Methods, systems, and apparatuses for electromagnetic interference (EMI) shielding are provided. An apparatus comprises a plurality of electrical components coupled to a substrate. The plurality of electrical components comprises a first electrical component coupled to a first region of the substrate and at least one other electrical component coupled to at least one other region of the substrate. The first electrical component is configured to emit electromagnetic waves. The apparatus also comprises an EMI shield forming a conductive envelopment around the first region. The first electrical component is inside the conductive envelopment and the one other electrical component is outside of the conductive envelopment. The EMI shield comprises an aperture positioned above the first electrical component. The apparatus further comprises a lens coupled to the EMI shield. The lens is positioned above the first electrical component and is substantially aligned with the aperture.