Semiconductor Package Stiffener Ring Thermal Dissipation

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Solution Overview

Problem

The challenge in semiconductor packaging is effectively dissipating heat without compromising the structural rigidity of the package, especially as die power consumption, size, and heat density increase with new microprocessor generations.

Innovation Solution

A semiconductor package design featuring a package substrate with an interposer, two semiconductor dies mounted side-by-side, and a stiffener ring with reinforcement ribs that encircles the dies, directly bonded to a heat sink through a thermal interface material, enhancing thermal dissipation and structural rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a metal lid is used to dissipate heat from the chip, then heat dissipation is improved, but structural rigidity deteriorates

Engineering Contradiction:
Improveheat dissipationVSAvoidstructural rigidity
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The package structure is divided into distinct functional components: a package substrate for structural support, a separate heat sink for thermal management, and an interposer for electrical interconnection. This segmentation allows each component to optimize its specific function without compromising overall structural integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The package employs composite material construction with a rigid package substrate (e.g., ceramic or high-strength polymer) combined with a thermally conductive heat sink. This composite approach enables simultaneous achievement of structural rigidity and effective heat dissipation through material property complementarity.

Inventive Principle:
Principle #40Composite materials

2Productivity

If die size and heat density increase to improve processing power, then productivity is improved, but heat dissipation becomes more difficult

Engineering Contradiction:
Improveprocessing powerVSAvoidheat dissipation difficulty
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

A thermally conductive interface material is introduced as an intermediary between the high-power die and the heat sink. This intermediary ensures efficient thermal transfer from the concentrated heat source (high-density die) to the heat dissipation structure, overcoming the heat dissipation challenges posed by increased power density.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The heat dissipation approach transitions from planar (through the metal lid) to three-dimensional by implementing a heat sink structure that extends vertically from the package substrate. This dimensional change increases the thermal dissipation surface area and improves heat removal capability for high-power dies.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Strength

If a stiffener is added to fix the semiconductor chip and interposer substrate, then structural rigidity is improved, but device complexity increases

Engineering Contradiction:
Improvestructural rigidityVSAvoidpackage structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The stiffener function is merged with the package substrate by integrating reinforcement ribs directly into the substrate structure. This integration provides structural rigidity without adding separate stiffener components, thereby reducing overall device complexity while maintaining enhanced mechanical strength.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The package substrate is designed to serve multiple functions simultaneously: it provides the mounting platform for the interposer and dies, establishes electrical connections, and incorporates reinforcement features for structural rigidity. This multi-functionality eliminates the need for dedicated stiffener components.

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 design improves thermal dissipation and structural integrity by directly bonding the heat sink to the semiconductor dies via reinforcement ribs, effectively managing high thermal stresses and maintaining package rigidity.

Implementation Method 1

a heat sink directly bonded to the rear surface of the first semiconductor die and the rear surface of the second semiconductor die through a thermal interface material (TIM) layer

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3373331B1Semiconductor package with stiffener ring
Publication Date: 2020.11.04 MEDIATEK INC
  • EP3373331B1 patent drawingFigure 1~2
  • EP3373331B1 patent drawingFigure 3~4
  • EP3373331B1 patent drawingFigure 5~6

AI summary

A semiconductor package (1a) includes a package substrate (10) having a top surface (10a) and a bottom surface (10b), an interposer (20) mounted on the top surface (10a) of the package substrate (10), a first semiconductor die (31) and a second semiconductor die (32) mounted on the interposer (20) in a side-by-side manner, and a stiffener ring (40) secured to the top surface (10a) of the package substrate (10). The stiffener ring (40) encircles the first semiconductor die (31) and the second semiconductor die (32). The stiffener ring (40) comprises a reinforcement rib (401) striding across the interposer (20).