Semiconductor Package Recess Mounting for Stable Heat Dissipation

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Solution Overview

Problem

Conventional semiconductor devices face reduced heat dissipation properties due to limited contact area between the heat sink and cooling medium, and instability in joining members under severe environments.

Innovation Solution

A semiconductor device design featuring a semiconductor package with a heat spreader and electrode terminals sealed in resin, supported by a heat sink with a recess that exceeds the thickness of an insulation sheet, ensuring the package is joined without being covered by the heat sink, and is stabilized by the recess's side wall.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the heat sink and insulation sheet are covered by the semiconductor package, then displacement and separation between components are prevented, but the contact area between the heat sink and cooling medium is limited, reducing heat dissipation property

Engineering Contradiction:

Improvestability of joining between membersVSAvoidheat dissipation property

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

Instead of covering the heat sink with the semiconductor package as in conventional designs, this invention inverts the arrangement by having the heat sink cover the semiconductor package. The heat sink's recess receives the bottom surface of the semiconductor package, allowing the heat sink to extend beyond the package boundaries and achieve full contact with the cooling medium while maintaining component stability through the recess structure.

Inventive Principle:

Principle #13The other way round (Inversion)

2Loss of energy

If the semiconductor package is fully covered by the heat sink, then heat dissipation is improved, but the joining stability between the semiconductor package, insulation sheet, and heat sink may be compromised

Engineering Contradiction:

Improveheat dissipation propertyVSAvoidstability of joining between members

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The heat sink contains a recess that receives and nests the bottom surface of the semiconductor package. This nesting arrangement allows the heat sink to cover the package for improved heat dissipation while the recess structure provides mechanical support and positioning, preventing displacement and separation between the joined components.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Reliability

If the heat sink recess depth is greater than the insulation sheet thickness, then the semiconductor package is properly supported in the recess, but the insulation sheet may be compressed or deformed

Engineering Contradiction:

Improvesupport stability of semiconductor packageVSAvoidinsulation sheet integrity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The recess depth is designed to be greater than the insulation sheet thickness, creating a localized support structure. The deeper recess provides mechanical support and positioning for the semiconductor package bottom surface, while the insulation sheet maintains its insulating function. The local quality of the recess structure allows it to provide support without requiring uniform compression of the insulation sheet throughout.

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

This design suppresses heat dissipation reduction while preventing displacement and separation of joining parts, enhancing stability and insulation properties.

Implementation Method 1

a heat sink having a recess in which the bottom surface of the semiconductor package is stored

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the contact area between the heat sink and a cooling medium

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 3

an insulation sheet provided at the bottom surface of the semiconductor package

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Data Source

PatentUS20250343093A1Semiconductor device

Publication Date: 2025.11.06 MITSUBISHI ELECTRIC CORP

AI summary

A semiconductor device according to one aspect of the present disclosure includes: a semiconductor package in which a heat spreader, a semiconductor chip provided on one surface of the heat spreader, and an electrode terminal electrically connected to the semiconductor chip are sealed with resin, the semiconductor package having a bottom surface at which another surface of the heat spreader is exposed from the sealing resin, an insulation sheet provided at the bottom surface of the semiconductor package; and a heat sink having a recess in which the bottom surface of the semiconductor package is stored, a depth of the recess being greater than a thickness of the insulation sheet, a bottom surface of the recess and the bottom surface of the semiconductor package being joined to each other via the insulation sheet, thus supporting the semiconductor package in the recess.