Chip Scale Isolator High Permittivity Dielectric Field Confinement

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Solution Overview

Problem

Chip-scale isolators face breakdown issues due to high electric field strengths at the edges of conductive structures, which can lead to electrical breakdown even with increased insulator thickness, as the reduced dimensions introduce new failure mechanisms not seen in discrete component isolators.

Innovation Solution

Incorporating a body of first dielectric material with a tapered or step-wise form and at least one region of second dielectric material with higher relative permittivity than the first material, which is formed to reduce electric field strength adjacent to conductive structures, thereby increasing the breakdown voltage and preventing electrical breakdown.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the thickness of dielectric material between electrodes is increased to increase breakdown voltage, then the breakdown voltage increases, but the device dimensions increase and chip-scale integration becomes difficult

Engineering Contradiction:
Improvebreakdown voltageVSAvoiddielectric layer thickness
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent applies local quality by using different dielectric materials with different permittivities in different regions of the isolator device. Specifically, a first dielectric material with higher permittivity is used in regions where electric field concentration is problematic (such as under conductive structures), while a second dielectric material with lower permittivity is used in other regions. This local differentiation allows the device to achieve high breakdown voltage without requiring uniformly thick dielectric layers throughout the entire device, thus resolving the contradiction between reliability and device dimensions.

Inventive Principle:
Principle #3Local quality

2Volume of moving object

If chip-scale dimensions are reduced to achieve miniaturization, then the device size decreases, but new breakdown mechanisms appear due to high electric field strengths at edges of conductive structures

Engineering Contradiction:
Improvedevice sizeVSAvoidelectrical breakdown resistance
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying the permittivity parameter of dielectric materials in specific regions to address edge effects. By using a first dielectric material with higher permittivity adjacent to conductive structures, the electric field distribution is altered to reduce field strength at critical edges. This parameter modification allows chip-scale miniaturization while preventing electrical breakdown mechanisms that would otherwise occur at reduced dimensions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If higher permittivity dielectric material is used to confine electric fields, then the voltage threshold before breakdown increases, but the device complexity increases due to multiple dielectric layers

Engineering Contradiction:
Improvevoltage thresholdVSAvoiddielectric layer structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the dielectric structure into distinct regions with different materials. The isolator device is segmented into areas containing a first dielectric material with higher permittivity and areas containing a second dielectric material with lower permittivity. This segmentation allows each region to perform its specific function optimally while maintaining an overall manageable device structure that can be fabricated using standard semiconductor processing techniques.

Inventive Principle:
Principle #1Segmentation

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 use of higher permittivity dielectric materials effectively confines strong electric fields away from the lower permittivity dielectric layers, increasing the voltage threshold before dielectric breakdown occurs, enhancing the reliability of chip-scale isolators.

Implementation Method 1

at least one region of second dielectric material between the first dielectric material and at least one of the first and second conductive structures, wherein the second dielectric material has a higher relative permittivity than the first material

Methodology Applied
Scientific EffectDielectric permittivity: Dielectric Permittivity

Data Source

PatentEP3159946B1Chip scale isolator device
Publication Date: 2021.09.01 ANALOG DEVICES INT UNLTD CO
  • EP3159946B1 patent drawingFigure 1
  • EP3159946B1 patent drawingFigure 2
  • EP3159946B1 patent drawingFigure 3

AI summary

An isolator device is provided comprising a body of first dielectric material (90, 92, 94) between the first (52) and second conductors (100), such as primary and secondary coils of a micro-transformer. A region of second dielectric material (302, 304) is provided between the body of first dielectric material and at least one of the first (52) and second conductors (100), wherein the second dielectric material (302, 304) has a higher relative permittivity than the first dielectric material (90, 92, 94). This provides enhanced ability to withstand the electric fields generated at the edge of a conductor. The body of the first dielectric material (90, 92, 94) can be tapered to provide stress relief to prevent the second dielectric material (302, 304) from developing stress cracks.