Multi-Level Heat Spreader for PoINT Die Stress Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Microelectronic packages using Patch-on-Interposer (PoINT) technology face challenges with die stress, solder squeeze-out issues, cantilever effects, and incompatibility with conventional Land Grid Array (LGA) packages due to the thickness and structural differences, leading to delamination, thermal interface material voiding, and the need for dedicated Independent Loading Mechanisms (ILMs).

Innovation Solution

The implementation of an Integrated Heat Spreader (IHS) with multi-level contact, making contact with both the patch and interposer, allows for the use of conventional LGA ILMs and enables interchangeable PoINT and LGA packages, reducing die stress and package real estate requirements by selectively eliminating unnecessary contact points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If PoINT technology is used to reduce package cost, then manufacturing cost is reduced, but die stress and reliability worsen

Engineering Contradiction:

Improvepackage costVSAvoiddie stress

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent segments the heat spreader into multiple levels: a first level contacting the patch and a second level contacting the interposer. This segmentation allows differential stress management at different locations, reducing overall die stress while maintaining the cost benefits of PoINT architecture.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a vertical dimension to the heat spreader structure by creating multi-level contact surfaces at different heights. The first level is at a first height contacting the patch, and the second level is at a second height contacting the interposer, allowing stress distribution in the vertical dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If conventional LGA ILMs are used with PoINT packages, then compatibility is improved, but die stress management worsens

Engineering Contradiction:

ImproveILM compatibilityVSAvoiddie stress

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The heat spreader is designed with multi-functional contact surfaces that serve both thermal management and mechanical stress distribution functions. The first level provides universal compatibility with conventional LGA ILMs while the second level provides specialized contact with the interposer for stress management.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The second level of the heat spreader acts as an intermediary between the ILM and the interposer, providing a dedicated contact surface that mediates stress distribution. This intermediary structure allows conventional ILMs to work with PoINT packages while properly managing die stress.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If heat spreader contacts only the patch, then manufacturing is simplified, but thermal management and stress distribution worsen

Engineering Contradiction:

Improveheat spreader assemblyVSAvoidthermal management

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The heat spreader is segmented into multiple contact levels: the first level contacts the patch for simplified manufacturing, while the second level contacts the interposer to extend thermal management and stress distribution capabilities without significantly complicating the assembly process.

Inventive Principle:

Principle #1Segmentation

4Reliability

If PoINT package thickness is increased, then die stress is reduced, but package real estate and compatibility worsen

Engineering Contradiction:

Improvedie stressVSAvoidpackage real estate

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

Instead of increasing package footprint area, the patent utilizes the vertical dimension by creating multi-level contact surfaces at different heights. This allows stress distribution and thermal management improvements without increasing the horizontal package real estate requirements.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 manages die stress, eliminates solder thermal interface material voiding, and allows for the use of compatible ILMs across different package types, enhancing the reliability and compatibility of microelectronic packages.

Implementation Method 1

a heat spreader adjacent to a second surface of the die. The heat spreader makes contact with both the first substrate and the second substrate

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS9478476B2Package for a microelectronic die, microelectronic assembly containing same, microelectronic system, and method of reducing die stress in a microelectronic package

Publication Date: 2016.10.25 INTEL CORP

AI summary

A package for a microelectronic die (110) includes a first substrate (120) adjacent to a first surface (112) of the die, a second substrate (130) adjacent to the first substrate, and a heat spreader (140) adjacent to a second surface (111) of the die. The heat spreader makes contact with both the first substrate and the second substrate.