Semiconductor Stem With Nested Metal Block For Heat Dissipation

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Solution Overview

Problem

The existing stem for semiconductor packages has limited heat dissipation performance when a second heat sink with a larger diameter is bonded to the eyelet, which increases the size of the light source module and hampers efficient heat dissipation.

Innovation Solution

A stem design featuring a circular plate-shaped eyelet with a through-hole, a metal base with higher thermal conductivity than the eyelet, and a metal block inserted into the through-hole, where the metal block projects from the eyelet's surface to provide a device mounting surface and enhance heat dissipation, with a thermally conductive bonding material used to secure the components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a second heat sink with a larger diameter than the eyelet is bonded to the eyelet, then the heat dissipation performance is improved, but the size of the light source module increases

Engineering Contradiction:

Improveheat dissipation performanceVSAvoidsize of light source module

Core Design Contradiction:

TemperatureVSArea of stationary object

Solution Approach 1:

The patent applies nesting by placing the metal block inside the through-hole of the eyelet. The metal block is inserted into the through-hole and its lower surface aligns with the lower surface of the eyelet, creating a nested structure that maximizes heat dissipation within the existing footprint without increasing the overall module size

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from a two-dimensional heat dissipation approach (bonding a larger heat sink to the surface) to a three-dimensional approach by utilizing the vertical space within the through-hole. The metal block extends from the lower surface upward into the through-hole, utilizing the Z-dimension to improve heat dissipation without increasing the X-Y plane area

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Temperature

If a second heat sink with a larger diameter than the eyelet is bonded to the eyelet, then the heat dissipation performance is improved, but the thickness of the bonding material increases, reducing thermal conductivity

Engineering Contradiction:

Improveheat dissipation performanceVSAvoidthickness of bonding material

Core Design Contradiction:

TemperatureVSLength of stationary object

Solution Approach 1:

By nesting the metal block within the through-hole and aligning its lower surface with the lower surface of the eyelet, the patent eliminates the need for thick bonding material. The metal block makes direct contact with the eyelet's lower surface, minimizing the bonding material thickness to only what is needed for secure attachment, thereby maintaining high thermal conductivity

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent uses a thermally conductive bonding material as an intermediary between the metal block and the eyelet's lower surface. This bonding material is applied in minimal thickness only where necessary for attachment, serving as a thin thermal bridge rather than a thick insulating layer, thus maintaining effective heat transfer

Inventive Principle:

Principle #24Intermediary (Mediator)

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 improves heat dissipation performance by ensuring the metal block's lower surface aligns with the eyelet's surface, allowing for efficient heat transfer and reducing the thickness of the bonding material to maintain high thermal conductivity, thus effectively dissipating heat generated by semiconductor devices.

Implementation Method 1

the metal base has a thermal conductivity that is higher than or equal to a thermal conductivity of the eyelet... efficient heat transfer... dissipating heat generated by semiconductor devices

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11349278B2Stem for semiconductor package, and semiconductor package

Publication Date: 2022.05.31 SHINKO ELECTRIC IND CO LTD

AI summary

A stem for a semiconductor package, includes an eyelet having a first surface, a second surface opposite to the first surface, and a through-hole penetrating the eyelet from the first surface to the second surface, a metal base bonded to the second surface of the eyelet so as to cover one end of the through-hole, and a metal block having one end thereof inserted into the through-hole and bonded to the metal base inside the through-hole, and another end projecting from the first surface of the eyelet and including a device mounting surface on which a semiconductor device is mounted. The metal base has a thermal conductivity higher than or equal to a thermal conductivity of the eyelet, and a surface at the one end of the metal block matches the second surface of the eyelet.