Flip Chip Module Multi-Layer Mold Compound Thermal Management

Solution Overview

Problem

High-performance semiconductor dies generate significant heat due to dense integration of transistors, requiring improved heat dissipation in flip chip packaging without increasing package size.

Innovation Solution

A method involving multiple mold compounds is used, where a first mold compound provides protection, a second mold compound with ferrite nanopowder enhances magnetic permeability, and a third mold compound with thermally conductive additives improves thermal conductivity, combined with an etching and filling process to create a flip chip module with enhanced thermal performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional single mold compound is used to encapsulate flip chip dies, then protection against environmental damage is provided, but thermal performance and heat dissipation are insufficient

Engineering Contradiction:

Improveheat dissipationVSAvoidprotection against environmental damage

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The encapsulation is divided into multiple mold compound layers, each with distinct functions: the first mold compound layer provides environmental protection and mechanical strength, while the second mold compound layer provides thermal management. This segmentation allows each layer to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses composite mold compounds with different material compositions. The first mold compound contains silica particulates for mechanical strength and protection, while the second mold compound contains thermally conductive additives for heat dissipation. This composite approach enables simultaneous achievement of protection and thermal performance.

Inventive Principle:

Principle #40Composite materials

2Temperature

If thermally conductive mold compound is used to improve heat dissipation, then thermal performance is enhanced, but mechanical strength and protection are compromised

Engineering Contradiction:

Improvethermal conductivityVSAvoidmechanical strength

Core Design Contradiction:

TemperatureVSStrength

Solution Approach 1:

The encapsulation is divided into multiple mold compound layers, each with distinct functions: the first mold compound layer provides environmental protection and mechanical strength, while the second mold compound layer provides thermal management. This segmentation allows each layer to optimize its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses composite mold compounds with different material compositions. The first mold compound contains silica particulates for mechanical strength and protection, while the second mold compound contains thermally conductive additives for heat dissipation. This composite approach enables simultaneous achievement of protection and thermal performance.

Inventive Principle:

Principle #40Composite materials

3Adaptability or versatility

If ferrite nanopowder is added to enhance magnetic permeability, then magnetic properties are improved, but manufacturing complexity increases

Engineering Contradiction:

Improvemagnetic permeabilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines ferrite nanopowder with the mold compound material during the encapsulation process. This integration allows the magnetic properties to be incorporated into the existing manufacturing workflow without requiring separate processing steps, thereby minimizing manufacturing complexity while achieving the desired magnetic permeability.

Inventive Principle:

Principle #5Merging (Combining)

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 method effectively enhances thermal performance of encapsulated flip chip dies, improving heat dissipation while maintaining package size and mechanical strength, and magnetic properties.

Implementation Method 1

Some of the mold compounds can be used as a barrier withstanding chemistries such as potassium hydroxide (KOH), sodium hydroxide (NaOH), and acetylcholine (ACH) without breakdown

Methodology Applied

Scientific EffectChemical barrier:

Implementation Method 2

the first mold compound includes a ferrite nanopowder to provide magnetic permeability

Methodology Applied

Scientific EffectFerromagnetism: Ferromagnetism

Implementation Method 3

the third mold compound includes a thermally conductive additive to provide thermal conductance through the third mold compound

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3332419B1Flip chip module with enhanced properties

Publication Date: 2023.03.29 QORVO US INC

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AI summary

A flip chip module having at least one flip chip die is disclosed. The flip chip module includes a carrier having a top surface with a first mold compound residing on the top surface. A first mold compound is disposed on the top surface of the carrier. A first thinned flip chip die resides over a first portion of the first mold compound with interconnects extending through the first portion to the top surface wherein the first portion of the mold compound fills a region between the first flip chip die and the top surface. A second mold compound resides over the substrate and provides a first recess over the first flip chip die wherein the first recess extends to a first die surface of the first flip chip die. A third mold compound resides in the first recess and covers an exposed surface of the flip chip die.