Insulating Thermal Interface on Encapsulation Discontinuity

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Solution Overview

Problem

The existing encapsulation structures in electronic semiconductor packages face issues with electrical leakage currents due to delamination of thermal interface materials, which compromises the dielectric strength and reliability, especially under high mechanical or electrical loads.

Innovation Solution

A method is introduced where a discontinuity is formed in the encapsulation structure, which is then filled with an electrically insulating thermal interface material, increasing the path length for leakage currents and enhancing adhesion, thereby improving dielectric strength and reliability by creating a robust electrical insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If thermal interface material is applied on the encapsulation structure, then thermal coupling is improved, but delamination occurs leading to leakage currents

Engineering Contradiction:

Improvethermal couplingVSAvoiddielectric strength

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The encapsulation structure is segmented by forming a discontinuity ( groove or recess) in the encapsulant material. This segmentation creates a distinct interface region where thermal interface material can be applied, improving thermal coupling while the discontinuity itself acts as a barrier to prevent delamination and leakage currents, thus maintaining dielectric strength

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The thermal interface material is applied locally at the discontinuity of the encapsulation structure rather than uniformly across the entire surface. This local application concentrates the thermal coupling benefit at the critical interface region while the discontinuity design ensures that this localized material maintains proper adhesion and prevents electrical leakage

Inventive Principle:

Principle #3Local quality

2Temperature

If thermal interface material is applied to improve thermal coupling, then heat dissipation is enhanced, but adhesion problems cause leakage currents

Engineering Contradiction:

Improveheat dissipationVSAvoidleakage currents

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The discontinuity (groove or recess) is formed in the encapsulation structure before applying the thermal interface material. This pre-formed structure acts as a cushioning measure that ensures proper adhesion of the thermal interface material and prevents future delamination, thereby preventing leakage currents while maintaining heat dissipation capability

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Strength

If the encapsulation structure is made continuous, then mechanical strength is maintained, but leakage currents can form more easily

Engineering Contradiction:

Improvemechanical strengthVSAvoidelectrical insulation

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

A discontinuity is introduced into the encapsulation structure, segmenting it into regions separated by the groove or recess. This segmentation creates a longer leakage current path and provides a mechanical interlock for the thermal interface material, improving electrical insulation while the overall encapsulation structure maintains its mechanical strength through the distributed design

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

This approach significantly increases the dielectric strength and operational reliability of the semiconductor package, making it suitable for high electric voltages and reducing the susceptibility to leakage currents, while ensuring reliable thermal coupling and mechanical protection.

Implementation Method 1

an electrically insulating thermal interface structure, which covers at least one part of the discontinuity and a volume connected thereto, which adjoins the carrier, wherein the thermal interface structure electrically decouples at least one part of the carrier with respect to its surroundings

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

a thermal interface structure... in order to be able to discharge accumulated waste heat from the electronic semiconductor package to the periphery during the operation

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11049790B2Electrically insulating thermal interface on the discontinuity of an encapsulation structure

Publication Date: 2021.06.29 INFINEON TECHNOLOGIES AG

AI summary

Method for manufacturing an electronic semiconductor package, in which method an electronic chip (100) is coupled to a carrier, the electronic chip is at least partially encapsulated by means of an encapsulation structure having a discontinuity, and the carrier is partially encapsulated, and at least one part of the discontinuity and a volume connected thereto adjoining an exposed surface section of the carrier are covered by an electrically insulating thermal interface structure, which electrically decouples at least one part of the carrier with respect to its surroundings.