Multi-Layer Package Lid for Hot-Spot Heat Dissipation

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Solution Overview

Problem

Semiconductor packages face challenges in thermal management due to non-uniform heat distribution, leading to hot spots and potential damage from inefficient heat dissipation in packages made of single materials like copper.

Innovation Solution

A package lid with a spatially varying thermal conductivity, incorporating a metal/diamond composite material supported by a copper layer, which enhances heat dissipation efficiency and reduces thermal-expansion induced warpage by adjusting the coefficient of thermal expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single material like copper is used for the package lid, then the manufacturing process is simple, but the heat dissipation efficiency is insufficient leading to hot spots

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidheat dissipation efficiency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The package lid is constructed as a composite structure with a first region containing a first material (e.g., copper) and a second region containing a second material (e.g., diamond or diamond-like carbon) having higher thermal conductivity. This composite approach enables the lid to effectively dissipate heat from high-power semiconductor devices by utilizing the superior thermal properties of the second material in regions requiring enhanced heat removal, while maintaining manufacturability through established bonding processes.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If a single material is used for the package lid, then the structure is uniform and easy to manufacture, but thermal-expansion induced warpage occurs

Engineering Contradiction:

Improvestructural uniformityVSAvoidthermal expansion stability

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The package lid employs local quality by having different materials in different regions: the first material (e.g., copper) provides structural uniformity and ease of manufacture, while the second material (e.g., diamond) in the second region provides thermal expansion stability. This spatial differentiation of material properties allows the lid to resist thermal-expansion induced warpage in high-heat regions while maintaining overall manufacturability.

Inventive Principle:

Principle #3Local quality

3Reliability

If high thermal conductivity material is used throughout, then heat dissipation is improved, but manufacturing complexity and cost increase

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidmulti-layer structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Rather than using high thermal conductivity material throughout the entire package lid, the invention applies the high thermal conductivity second material (e.g., diamond) only in the second region where enhanced heat dissipation is most needed. This localized approach improves heat dissipation efficiency at critical hot spots while avoiding the manufacturing complexity and cost associated with fabricating an entirely complex multi-layer structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention applies partial action by implementing the second material with higher thermal conductivity only in specific regions (second region) where it is most needed for heat dissipation, rather than throughout the entire package lid. This partial application achieves the necessary heat management performance while minimizing manufacturing complexity and material costs.

Inventive Principle:

Principle #16Partial or excessive action

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 solution effectively increases heat dissipation efficiency and mitigates thermal-expansion related deformations, providing improved structural stability and heat management in semiconductor packages.

Implementation Method 1

A package lid with a spatially varying thermal conductivity, incorporating a metal/diamond composite material supported by a copper layer, which enhances heat dissipation efficiency

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

reduces thermal-expansion induced warpage by adjusting the coefficient of thermal expansion

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS20240290683A1Package lid including a multi-layer structure for heat dissipation and methods of forming the same

Publication Date: 2024.08.29 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

An embodiment semiconductor package structure may include a package substrate, a semiconductor die coupled to the package substrate, and a package lid attached to the package substrate and covering the semiconductor die. The package lid may include a top portion having a spatially varying thermal conductivity that is greater in a first region than in a second region. The first region may include a multi-layer structure including a metal/diamond composite material supported by a copper layer. The metal/diamond composite material may include a silver/diamond, copper/diamond, or aluminum/diamond material and may have a thermal conductivity that is within a range from 600 W/m·K to 900 W/m·K and a coefficient of thermal expansion that is in a second range from 5 ppm/° C. to 10 ppm/° C. The package lid may have an effective coefficient of thermal expansion that is in a range from 14.5 ppm/° C. to 17 ppm/° C.