Boron Nitride Heat Dissipation Sheet Cracking Prevention
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Solution Overview
Problem
Existing heat dissipation sheets using boron nitride aggregates suffer from cracking, falling, and poor insulation properties during the forming process, which hinders their thermal conductivity and insulation effectiveness.
Innovation Solution
A cured product of an organopolysiloxane composition containing a boron nitride aggregate, specifically formulated with organopolysiloxanes, organohydrogenpolysiloxanes, a peroxide cross-linking agent, and a platinum group catalyst, is used to create an insulating heat dissipation sheet that is hot-press cured to prevent cracking and enhance insulation properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If boron nitride aggregate with large average particle diameter is used as filler, then thermal conductivity is improved, but cracks occur easily and sheet falls away during forming
Solution Approach 1:
The patent optimizes the average particle diameter of boron nitride aggregate to a specific range (10-50 μm) to balance thermal conductivity and structural integrity. This parameter optimization prevents cracks and sheet falling during forming while maintaining high thermal conductivity, resolving the contradiction between improving thermal performance and ensuring structural reliability.
2Temperature
If boron nitride aggregate is used as filler, then thermal conductivity is improved, but insulation property deteriorates
Solution Approach 1:
The patent achieves directional thermal conductivity by controlling the orientation of boron nitride aggregate particles. The particles are arranged with their major axes aligned in the thickness direction of the sheet, creating high thermal conductivity in the heat transfer direction while maintaining insulation properties in the plane direction. This local quality differentiation resolves the contradiction between improving thermal conductivity and maintaining insulation.
3Ease of manufacture
If scale-like boron nitride is arranged along sheet direction, then manufacturing is simplified, but heat conductivity in thickness direction becomes insufficient
Solution Approach 1:
The patent transitions from in-plane arrangement to through-thickness orientation of boron nitride particles. By aligning the major axes of the scale-like particles perpendicular to the sheet plane (in the thickness direction), the patent enables efficient heat transfer across the sheet while maintaining manufacturing feasibility through unidirectional alignment processes.
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 resulting heat dissipation sheet exhibits improved thermal conductivity, heat resistance, and insulation properties, reducing the likelihood of cracking and falling during formation, and is cost-effective for use in electronic devices and integrated circuits.
Implementation Method 1
a platinum group curing catalyst
Implementation Method 2
a peroxide cross-linking agent
Implementation Method 3
a high thermal conductivity and an insulation property have been required in a thermally conductive layer for transferring heat from a heat generating member(s) to a heat dissipation member(s)
Implementation Method 4
The scale-like boron nitride has an anisotropic thermal conductivity where a high thermal conductivity is exhibited in a major axis direction (direction of axis a in hexagonal crystal), and a low thermal conductivity is exhibited in a minor axis direction (direction of axis c in hexagonal crystal)
Implementation Method 5
hot-press curing
Implementation Method 6
hot-press curing
Data Source
AI summary
Provided is an insulating heat dissipation sheet hardly producing cracks, and exhibiting a favorable insulation property. The insulating heat dissipation sheet consists of a cured product of an organopolysiloxane composition comprising: (a) 100 parts by mass of an organopolysiloxane exhibiting an average degree of polymerization of 3,000 to 10,000; (b) 10 to 100 parts by mass of an organopolysiloxane exhibiting an average degree of polymerization of 2 to 2,000, and having alkenyl groups only at both ends of a molecular chain thereof, but at no other position on the molecular chain; (c) 2 to 20 parts by mass of an organohydrogenpolysiloxane having hydrogen atoms directly bonded to silicon atoms (Si-H groups); (d) 100 to 300 parts by mass of a boron nitride aggregate; (e) 0.1 to 10 parts by mass of a peroxide cross-linking agent; and (f) 0.1 to 10 parts by mass of a platinum group curing catalyst.