Metal Cage EMI Shielding for Semiconductor Devices

Solution Overview

Problem

Existing EMI shielding solutions for semiconductor devices are either costly and large, shielding the entire die, or they fail to protect individual devices from both external and internal interference, and do not allow for independent testing of electronic devices.

Innovation Solution

A metal cage structure with a lateral and top EMI shield portion, comprising contacts and metal interconnect segments, is used to shield individual electronic devices on a semiconductor die, effectively protecting against both external and internal electromagnetic interference while occupying a small area and being cost-effective.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large shielding structure is used to protect the entire semiconductor die, then EMI protection is improved, but the area occupied and manufacturing cost increase

Engineering Contradiction:

ImproveEMI protectionVSAvoidarea occupied

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent divides the shielding structure into individual metal cages that surround specific electronic devices rather than shielding the entire die. Each metal cage is a segmented structure comprising vertical and horizontal metal segments positioned at different levels, creating localized EMI shields around individual devices or interconnect regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies EMI shielding selectively to specific locations where electronic devices or interconnects are present, rather than uniformly shielding the entire die. The metal cage structures are positioned only where needed to protect particular devices or signal paths, optimizing both protection and space utilization.

Inventive Principle:

Principle #3Local quality

2Reliability

If a large shielding structure is used to protect the entire semiconductor die, then EMI protection is improved, but manufacturing cost increases

Engineering Contradiction:

ImproveEMI protectionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent divides the shielding structure into individual metal cages that surround specific electronic devices rather than shielding the entire die. Each metal cage is a segmented structure comprising vertical and horizontal metal segments positioned at different levels, creating localized EMI shields around individual devices or interconnect regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies EMI shielding selectively to specific locations where electronic devices or interconnects are present, rather than uniformly shielding the entire die. The metal cage structures are positioned only where needed to protect particular devices or signal paths, optimizing both protection and space utilization.

Inventive Principle:

Principle #3Local quality

3Reliability

If the entire semiconductor die is shielded, then external EMI protection is improved, but the ability to independently test individual devices is lost

Engineering Contradiction:

Improveexternal EMI protectionVSAvoidindependent testing capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent divides the shielding structure into individual metal cages that surround specific electronic devices rather than shielding the entire die. Each metal cage is a segmented structure comprising vertical and horizontal metal segments positioned at different levels, creating localized EMI shields around individual devices or interconnect regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies EMI shielding selectively to specific locations where electronic devices or interconnects are present, rather than uniformly shielding the entire die. The metal cage structures are positioned only where needed to protect particular devices or signal paths, optimizing both protection and space utilization.

Inventive Principle:

Principle #3Local quality

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 metal cage structure effectively shields electronic devices from both external and internal EMI, allowing for independent testing and preventing interference between adjacent devices, while being economically viable and space-efficient.

Implementation Method 1

a first metal cage EMI shield structure 102, 102a, 102b surrounding the transistor 104... the metal cage structure effectively shields electronic devices from both external and internal EMI

Methodology Applied

Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 2

a number of metal interconnect segments forming a top EMI shield portion of the metal cage... EMI can propagate by induction, when an EMI signal is induced magnetically

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS7518067B2Metal cage structure and method for EMI shielding

Publication Date: 2009.04.14 GLOBALFOUNDRIES US INC

AI summary

According to one exemplary embodiment, a structure comprises an electronic device situated over a substrate of a semiconductor die. The structure further includes a metal cage comprising a number of contacts situated over the substrate and surrounding the electronic device. The contacts form a lateral EMI shield portion of the metal cage. The structure also includes a number of vias connecting a number of metal interconnect segments to the contacts. The metal interconnect segments form a top EMI shield portion of the metal cage.