Thermal Silicone Composition Balancing Conductivity and Flexibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional silicone compositions face challenges in maintaining flexibility, long-term reliability, and preventing oil bleeding while increasing thermal conductivity, particularly due to high filler content leading to increased viscosity and hardness, which can cause detachment from heat-generating elements.
Innovation Solution
A two-part curing type silicone composition is developed with a specific ratio of Si—H to alkenyl groups and controlled viscosity difference between components, using organopolysiloxane and organohydrogenpolysiloxane, along with a thermally conductive filler and curing catalyst, to enhance flexibility and reliability while maintaining high thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the filling ratio of thermally conductive filler is increased to improve thermal conductivity, then thermal conductivity is improved, but viscosity increases and flowability decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the silicone resin, specifically using a mixture of polydimethylsiloxane and polyphenylsiloxane in controlled ratios, and adjusts the crosslinking agent composition to optimize the balance between thermal conductivity and flowability while maintaining high filler content
Solution Approach 2:
The patent uses a composite material system combining multiple components: silicone resin base, crosslinking agents, thermally conductive filler particles, and auxiliary agents. This composite approach allows optimization of each component's contribution to achieve both high thermal conductivity and acceptable flowability
2Temperature
If the filling ratio of thermally conductive filler is increased to improve thermal conductivity, then thermal conductivity is improved, but hardness increases and stress on surrounding components increases
Solution Approach 1:
The patent carefully controls the crosslinking density by adjusting the ratio and amount of crosslinking agents (using both condensation-type and addition-type crosslinking mechanisms), which allows high filler content to be achieved while maintaining appropriate hardness and reducing stress on surrounding components
Solution Approach 2:
The composite material system includes filler particles with specific size distributions, silicone resin with controlled molecular weight and structure, and multiple crosslinking agents working synergistically to create a matrix that supports high filler loading while maintaining mechanical flexibility
3Ease of operation
If the second agent contains alkenyl group-containing organopolysiloxane in addition to organohydrogenpolysiloxane to equalize mass ratio, then mass ratio equality is achieved, but oil bleeding occurs during storage
Solution Approach 1:
The patent extracts the alkenyl group-containing organopolysiloxane from the second agent (crosslinking agent container) and places it exclusively in the first agent (base material container), preventing oil bleeding while maintaining the ability to achieve proper mixing ratios through controlled dispensing
Solution Approach 2:
The patent introduces auxiliary agents including silane coupling agents and surface treatment agents that act as intermediaries between the filler particles and the silicone resin matrix, improving compatibility and preventing phase separation that would lead to oil bleeding during storage
4Temperature
If filling ratio of thermally conductive filler is increased to improve thermal conductivity, then thermal conductivity is improved, but long-term reliability decreases due to hardness increase under high temperature
Solution Approach 1:
The patent uses silicone resin with specific molecular weight ranges and polyphenylsiloxane content (5-50 mass%) that remains stable under high temperature conditions, preventing excessive crosslinking and hardness increase that would lead to detachment, while still achieving high thermal conductivity through optimized filler loading
Solution Approach 2:
The composite material system incorporates heat-stable silicone resin components, surface-treated filler particles, and dual crosslinking mechanisms that work synergistically to maintain structural integrity and thermal performance under prolonged high-temperature operation, ensuring long-term reliability
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 composition achieves improved flexibility, long-term reliability, and reduced oil bleeding, ensuring the heat-dissipating member remains adhered to heat-generating elements even under high-temperature and vibrational conditions.
Implementation Method 1
a two-part curing type silicone composition... the first agent to contain an alkenyl group-containing organopolysiloxane and for the second agent to contain an organohydrogenpolysiloxane
Implementation Method 2
a thermally conductive filler... to enhance flexibility and reliability while maintaining high thermal conductivity
Data Source
AI summary
A silicone composition comprising: (a) a specific organopolysiloxane; (b) an organohydrogenpolysiloxane having Si—H at both two molecular chain ends and molecular-chain side chains, the number of Si—H in the molecular-chain side chains being 4 to 15; (c) a thermally conductive filler; and (d) a curing catalyst; the silicone composition comprising: a first agent comprising the components (a), (c) and (d) and not comprising the component (b) in combination with a second agent comprising the components (a), (b) and (c) and not comprising the component (d); a difference in viscosity at 23° C. between the components (a) and (b) in the second agent is 400 mPa·s or less; and a ratio (H/Vi) of the number of Si—H to the number of alkenyl groups is in the range of 0.5 or more and 1.5 or less.