Interposer Heat Spreader for Vertical Thermal Dissipation

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Solution Overview

Problem

Conventional multiple-die packages face challenges with heat dissipation due to the use of low thermal conductivity materials in interposers, which restrict vertical heat dissipation and lead to increased temperatures and reduced reliability of electrical interconnects, especially as die density increases.

Innovation Solution

The implementation of a heat spreader with a cap thermally coupled to a die above an interposer and a pillar thermally coupled to a die below the interposer, allowing for enhanced vertical heat dissipation by extending through an opening in the interposer, along with thermal interface features to improve conductivity and secure the heat spreader.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional low thermal conductivity materials are used in interposers, then the interposer structure is simple and easy to manufacture, but vertical heat dissipation is restricted and temperatures increase

Engineering Contradiction:

Improveheat dissipationVSAvoidinterposer structure

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The heat spreader is divided into two functional segments: a cap portion that interfaces with the upper die and a pillar portion that extends through the interposer to interface with the lower die. This segmentation allows each portion to be optimized for its specific thermal management function while maintaining overall structural integrity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The heat spreader acts as an intermediary thermal management component between the upper and lower dies, with the pillar portion serving as a thermal conduit through the interposer. This intermediary structure enables heat to be conducted from both dies through the heat spreader to external heat sinks, resolving the heat dissipation limitation of conventional interposers

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If die density is increased to improve processing capacity, then more functionality is contained in small space, but heat-related problems become more acute

Engineering Contradiction:

Improveprocessing capacityVSAvoidheat dissipation

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The heat spreader utilizes the vertical dimension by extending the pillar portion through the interposer substrate, creating a three-dimensional heat dissipation pathway. This vertical thermal management approach complements traditional lateral heat spreading, providing enhanced heat removal capability that scales with increased die density without requiring larger package footprints

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If conventional interposer materials are used, then manufacturing is simpler, but reliability of electrical interconnects is reduced due to heat accumulation

Engineering Contradiction:

Improveelectrical interconnect reliabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The heat spreader structure serves multiple functions simultaneously: the cap portion provides thermal management for the upper die, the pillar portion conducts heat through the interposer, and the overall structure can be integrated with existing interposer manufacturing processes. This multi-functionality achieves improved reliability without proportionally increasing manufacturing complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 configuration significantly enhances vertical heat dissipation from semiconductor dies, improving performance and reliability while enabling further miniaturization and addressing heat-related issues in multiple-die packages.

Implementation Method 1

a heat spreader with a cap thermally coupled to a die above an interposer and a pillar thermally coupled to a die below the interposer, allowing for enhanced vertical heat dissipation by extending through an opening in the interposer

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS10971422B2Semiconductor die assembly having a heat spreader that extends through an underlying interposer and related technology

Publication Date: 2021.04.06 MICRON TECHNOLOGY INC

AI summary

A semiconductor die assembly in accordance with an embodiment of the present technology includes a first semiconductor die, a package substrate underlying the first semiconductor die, an interposer between the package substrate and the first semiconductor die, and a second semiconductor die between the package substrate and the interposer. The semiconductor die assembly further comprises a heat spreader including a cap thermally coupled to the first semiconductor die at a first elevation, and a pillar thermally coupled to the second semiconductor die at a second elevation different than the first elevation. The heat spreader is configured to transfer heat away from the first and second semiconductor dies via the cap and the pillar, respectively. The interposer extends around at least 75% of a perimeter of the pillar in a plane between the first and second elevations.