Magnesium Hydroxide Package Layer for TDDB Treeing Suppression

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Solution Overview

Problem

Early TDDB failure in packages due to electrical treeing at polyimide/oxide interfaces leads to device failure, and existing methods to hinder treeing within the epoxy molding compound are ineffective in stopping its progression outside the compound.

Innovation Solution

Incorporating a magnesium hydroxide layer at interfaces prone to electrical treeing, such as oxide/imide and encapsulation material interfaces, to act as a flame retardant, increase surface roughness, and improve interfacial interaction, thereby hindering treeing progression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrical treeing is allowed to progress in the package, then the breakdown path forms through the polyimide/oxide interface, but this leads to oxide erosion and device failure

Engineering Contradiction:

ImproveTDDB performanceVSAvoidelectrical treeing progression

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A magnesium hydroxide layer is introduced as an intermediary material between the polyimide and oxide layers at the interface. This intermediate layer acts as a barrier that interrupts the electrical treeing path, preventing direct contact and energy transfer between the polyimide and oxide, thereby protecting the oxide from erosion and improving TDDB performance

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The magnesium hydroxide layer utilizes the heat generated by electrical treeing as a beneficial effect. When electrical treeing occurs, the magnesium hydroxide absorbs the heat energy through endothermic decomposition, converting the harmful thermal energy into a protective mechanism that suppresses further treeing progression and protects the oxide layer

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If magnesium hydroxide layer is added at interfaces, then electrical treeing is restricted and TDDB performance improves, but the package structure becomes more complex

Engineering Contradiction:

ImproveTDDB performanceVSAvoidpackage structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The magnesium hydroxide layer is applied locally only at the critical polyimide/oxide interface where electrical treeing originates, rather than throughout the entire package. This localized application provides maximum protection at the most vulnerable point while minimizing the addition of structural complexity and material volume

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 magnesium hydroxide layer effectively restricts electrical treeing by absorbing heat, lengthening the breakdown path, and enhancing interfacial stability, improving TDDB performance, especially in high voltage applications and packages using wide bandgap materials.

Implementation Method 1

it is believed that the magnesium hydroxide may restrain an progression of electrical trees by absorbing heat generated by the electrical trees

Methodology Applied

Scientific EffectEndothermic reaction: Endothermic Reaction

Implementation Method 2

increasing a surface roughness of the interface between the polyimide and the oxide

Methodology Applied

Scientific EffectSurface roughness:

Data Source

PatentUS20260047479A1Package and method of forming a package

Publication Date: 2026.02.12 INFINEON TECHNOLOGIES AG

AI summary

A package is provided. The package includes an electronic chip and at least one magnesium hydroxide layer (Mg(OH)2) over the electronic chip. A method of forming the package is also described.