Agglomerated Boron Nitride Particles for 3D IC Thermal Management

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Solution Overview

Problem

Conventional boron nitride particles used in three-dimensional integrated circuits suffer from low thermal conductivity in the thickness direction due to their anisotropic structure, which limits the effectiveness of heat dissipation and leads to performance degradation.

Innovation Solution

The development of agglomerated boron nitride particles with radially arranged hexagonal boron nitride crystal primary particles, which enhances thermal conductivity in both the plane and thickness directions by increasing the contact frequency of highly conductive planes, thereby improving the thermal conductivity of the filling interlayer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional boron nitride particles are used as filler, then the composition can be formed into a filling interlayer, but the thermal conductivity in the thickness direction remains poor due to anisotropic structure

Engineering Contradiction:
Improvethermal conductivityVSAvoidanisotropic structure
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The boron nitride particles are segmented into primary particles (0.1-10 μm) that aggregate into larger particles (1-50 μm). This segmentation allows the primary particles to be oriented with their high thermal conductivity planes parallel to the lamination surface, while the aggregate structure provides isotropic thermal conductivity in the thickness direction, resolving the anisotropy problem.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses composite boron nitride particles consisting of multiple primary particles aggregated together. This composite structure combines the high in-plane thermal conductivity of individual BN crystals with isotropic thermal conductivity in the thickness direction through the aggregate morphology, achieving overall isotropic thermal conductivity in the filling interlayer.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If boron nitride particles are kneaded with resin, then a filling interlayer can be formed, but alignment problems occur due to particle shape and size

Engineering Contradiction:
Improvekneading propertyVSAvoidparticle alignment
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The boron nitride particles are designed with a spherical aggregate morphology composed of primary particles. This spherical shape improves kneading properties by reducing particle interlocking and facilitating uniform distribution in the resin, while the internal structure of radially arranged primary particles prevents unwanted alignment during the forming process.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The particles exhibit local quality with primary particles having specific crystal orientations (c-axis perpendicular to the lamination surface) while the overall aggregate maintains spherical symmetry. This local crystalline order within spherical aggregates provides good kneading properties without causing alignment issues in the bulk material.

Inventive Principle:
Principle #3Local quality

3Loss of energy

If the filling interlayer is formed with conventional particles, then the structure is completed, but heat dissipation efficiency is insufficient

Engineering Contradiction:
Improveheat dissipationVSAvoidheat accumulation
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The patent changes the particle size parameters and morphological parameters of the boron nitride filler. By controlling primary particle size (0.1-10 μm) and aggregate size (1-50 μm), and ensuring specific surface area (5-50 m²/g) and pore volume (0.1-2.0 mL/g), the filling interlayer achieves optimized thermal conductivity in both in-plane and thickness directions, enabling efficient heat dissipation and preventing heat accumulation.

Inventive Principle:
Principle #35Parameter changes

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 approach results in a three-dimensional integrated circuit with improved thermal conductivity in the thickness direction, enhanced kneading properties with resin, and a homogeneous coating film, leading to a high-quality circuit with effective heat dissipation.

Implementation Method 1

enhances thermal conductivity in both the plane and thickness directions

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3269682B1Agglomerated boron nitride particles, composition containing said particles, and three-dimensional integrated circuit having layer comprising said composition
Publication Date: 2020.01.01 MITSUBISHI CHEM CORP
  • EP3269682B1 patent drawingFigure 1(a)
  • EP3269682B1 patent drawingFigure 1(b)
  • EP3269682B1 patent drawingFigure 2(a)

AI summary

A composition for a three-dimensional integrated circuit, comprising agglomerated boron nitride particles constituted by primary particles of hexagonal boron nitride crystals, wherein the primary particles of hexagonal boron nitride crystals are arranged in a normal direction so that their a-axes face outward.