Semiconductor Package Insert for Isolated Heat Sink Coupling

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Solution Overview

Problem

Current semiconductor package configurations that thermally couple a die to a heat sink through an exposed die pad are limited when the die pad is electrically isolated, leading to unwanted process variations and increased time and expense in board assembly.

Innovation Solution

A semiconductor package design featuring a semiconductor die thermally coupled to a planar metal pad, with an encapsulant body having a recess that accommodates a curable polymer insert, allowing for efficient thermal coupling to a heat sink while maintaining electrical isolation, and utilizing overflow channels for height adjustment and adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If an exposed die pad is used for direct thermal coupling to heat sink, then thermal management efficiency is improved, but electrical isolation becomes problematic and assembly complexity increases

Engineering Contradiction:
Improvethermal management efficiencyVSAvoidassembly complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent introduces a thermally conductive insert as an intermediary component between the die pad and heat sink. This insert serves as a mediator that enables thermal coupling while maintaining electrical isolation, resolving the contradiction between efficient heat dissipation and electrical safety requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the thermal management function into distinct components: the die pad, the encapsulant body, the thermally conductive insert, and the heat sink. This segmentation allows each component to perform its specific function independently, simplifying assembly and reducing overall device complexity.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If traditional assembly methods are used for electrical isolation, then manufacturing process is simpler, but process variation increases and assembly time increases

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidprocess variation
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent incorporates the thermally conductive insert into the encapsulant body during the molding process, performing the electrical isolation and thermal conduction setup in advance. This preliminary action eliminates the need for separate assembly steps, reducing both assembly time and process variation while maintaining manufacturing simplicity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges multiple functions into the encapsulant body: structural protection, electrical isolation, and thermal conduction pathway provision. By combining these functions into a single integrated component, the manufacturing process becomes simpler with fewer discrete parts, while achieving precise electrical isolation without increasing assembly complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Temperature

If rigid thermal interface is used between die pad and heat sink, then thermal conduction is more efficient, but height discrepancies cause assembly difficulties

Engineering Contradiction:
Improvethermal conduction efficiencyVSAvoidheight adjustment capability
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The patent employs a curable polymer insert that transitions from a liquid or semi-liquid state to a solid state. In its uncured state, the polymer is fluid and can flow to accommodate height variations and form a planar interface. After curing, it becomes rigid to provide efficient thermal conduction. This dynamic state change allows the same material to adapt to height discrepancies and then maintain stable thermal contact.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical parameters of the thermal interface material by using a curable polymer that transitions between different states (liquid/semi-liquid to solid). This parameter change enables the material to first adapt to surface irregularities and height variations, then maintain stable, efficient thermal conduction after curing, resolving the contradiction between rigidity and adaptability.

Inventive Principle:
Principle #35Parameter changes

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 design enables efficient thermal management with reduced assembly complexity and cost by using a curable polymer insert that redistributes to form a planar interface with the heat sink, accommodating height discrepancies and ensuring reliable thermal conduction.

Implementation Method 1

joining the heat sink to each of the inserts comprises flowing material from the inserts laterally away from the recesses

Methodology Applied
Scientific EffectMaterial flow:

Implementation Method 2

an insert arranged within the recess that is thermally coupled to the die pad and extends to the outer upper side of the encapsulant body

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4376070A1Semiconductor package with insert
Publication Date: 2024.05.29 INFINEON TECH AUSTRIA AG
  • EP4376070A1 patent drawingFigure 1~1A
  • EP4376070A1 patent drawingFigure 1~1B
  • EP4376070A1 patent drawingFigure 2~2A

AI summary

A semiconductor package includes a semiconductor die thermally coupled to a planar metal pad, an encapsulant body that encapsulates the semiconductor die and includes a recess that extends from an outer upper side of the encapsulant body towards a rear side of the planar metal pad, and an insert arranged within the recess that is thermally coupled to the planar metal pad and extends to the outer upper side of the encapsulant body, wherein the insert that is arranged within the recess includes a curable polymer compound.