IC Package Lid and Hybrid TIM Structure for Multi-Die Cooling

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The semiconductor industry faces challenges in efficiently dissipating heat from integrated circuit dies while maintaining structural integrity and flexibility in packaging, particularly as devices shrink and generate varying amounts of heat.

Innovation Solution

The implementation of a hybrid heat sink structure using thermal interface materials (TIMs) with metallic and low-stress, non-metallic components, combined with a conformal lid assembly featuring protrusions and trenches, to enhance heat dissipation and reduce stress, improving the structural integrity and flexibility of integrated circuit packages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a conventional heat sink structure is used, then heat dissipation is achieved, but structural integrity and flexibility are compromised

Engineering Contradiction:

Improveheat dissipationVSAvoidstructural integrity

Core Design Contradiction:

TemperatureVSStrength

Solution Approach 1:

The heat sink is divided into multiple segments including a first heat sink portion and a second heat sink portion that can be independently attached to different dies. This segmentation allows each portion to be optimized for its specific thermal load while maintaining overall structural integrity through modular construction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs different materials for different portions of the heat sink structure. The first heat sink portion uses a material optimized for high thermal conductivity to handle high heat-generating dies, while the second heat sink portion uses a different material suited for low heat-generating dies, creating a composite structure that balances thermal performance with mechanical properties.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If thermal interface materials are applied uniformly to all dies, then manufacturing is simplified, but heat dissipation efficiency decreases due to varying heat generation

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidheat dissipation efficiency

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

Different thermal interface materials are applied to different portions of the heat sink structure. A first thermal interface material is applied between the first die and the first heat sink portion, while a second thermal interface material is applied between the second die and the second heat sink portion. This local differentiation optimizes thermal transfer for each die's specific heat generation characteristics.

Inventive Principle:

Principle #3Local quality

3Stability of the object's composition

If the lid assembly is made rigid, then structural stability is improved, but flexibility and stress reduction are compromised

Engineering Contradiction:

Improvestructural stabilityVSAvoidflexibility

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The lid assembly incorporates a recessed portion that can deform or flex in response to thermal expansion and contraction of the underlying components. This dynamic feature allows the rigid lid structure to accommodate dimensional changes during thermal cycling, maintaining structural stability while providing necessary flexibility.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The recessed portion in the lid assembly acts as a pre-designed stress relief feature that anticipates thermal expansion forces. By incorporating this compliant element beforehand, the structure can absorb thermal stresses without compromising the overall rigidity or requiring additional stress management components.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 solution effectively dissipates heat from both high and low heat-generating integrated circuit dies, maintaining structural integrity and flexibility, even under thermal cycling, by optimizing the contact area and stress distribution within the package.

Implementation Method 1

a first thermal interface material being attached to the first die, the first thermal interface material having a first thermal conductivity; a second thermal interface material being attached to the second die, the second thermal interface material having a second thermal conductivity

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS20240128148A1Integrated Circuit Packages and Methods of Forming the Same

Publication Date: 2024.04.18 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method includes attaching a package component to a package substrate, the package component includes: an interposer disposed over the package substrate; a first die disposed along the interposer; and a second die disposed along the interposer, the second die being laterally adjacent the first die; attaching a first thermal interface material to the first die, the first thermal interface material being composed of a first material; attaching a second thermal interface material to the second die, the second thermal interface material being composed of a second material different from the first material; and attaching a lid assembly to the package substrate, the lid assembly being further attached to the first thermal interface material and the second thermal interface material.