Graphite Thermal Conduction Sheet for Warpage-Resistant Heat Dissipation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thermal conduction sheets fail to effectively adjust to thermal deformation (warpage) in semiconductor packages, leading to detachment from heat generating and dissipating elements, which hampers heat dissipation.
Innovation Solution
A thermal conduction sheet with graphite particles oriented in the thickness direction, combined with a liquid component, acrylate-based polymer, ethylene-α-olefin copolymer, hot-melt agent, and antioxidant, providing an elastic modulus of 1.4 MPa or less and a tack strength of 5.0 N·mm or higher, ensuring stable adhesion and adjustability to warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional thermal conduction sheets are used, then thermal conductivity is maintained, but the sheets cannot adjust to warpage and detach from heat generating elements
Solution Approach 1:
The patent applies parameter changes by controlling the elastic modulus of the thermal conduction sheet to be within a specific range (0.1-10 MPa) through material composition adjustments. This allows the sheet to be soft enough to conform to warpage while maintaining sufficient adhesion strength to prevent detachment during thermal cycling and operation.
Solution Approach 2:
The patent uses composite materials by combining rubber base resin with specific additives including plasticizers, adhesives, and conductive fillers (graphite powder or metal particles). This composite structure enables the sheet to simultaneously achieve flexibility for warpage adjustment and adequate adhesion strength for reliable mounting.
2Temperature
If graphite particles are oriented in the thickness direction to improve thermal conductivity, then heat dissipation performance increases, but the sheet becomes more rigid and less adaptable to warpage
Solution Approach 1:
The patent controls the elastic modulus within a narrow range (0.1-10 MPa) even with graphite particle orientation, by carefully balancing the rubber base resin composition, plasticizer content, and particle loading. This maintains the sheet's flexibility for warpage adjustment while achieving improved thermal conductivity through particle orientation.
Solution Approach 2:
The patent applies local quality by orienting graphite particles primarily in the thickness direction where thermal conductivity is most critical for heat dissipation, while the in-plane properties remain more flexible due to the rubber matrix. This directional arrangement optimizes thermal performance without completely sacrificing adaptability to warpage.
3Adaptability or versatility
If the sheet is made softer to adjust to warpage, then adaptability improves, but adhesion strength decreases and detachment occurs
Solution Approach 1:
The patent uses composite materials by incorporating adhesive agents and plasticizers into the rubber base resin matrix. This composite structure enables the sheet to simultaneously achieve flexibility for warpage adjustment and adequate adhesion strength for reliable mounting, resolving the trade-off between softness and bonding strength.
Solution Approach 2:
The patent optimizes the elastic modulus to a specific range (0.1-10 MPa) that balances flexibility and adhesion. Within this range, the sheet is soft enough to conform to warpage but maintains sufficient mechanical strength to prevent detachment during thermal cycling and operation.
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 thermal conduction sheet maintains tight adhesion to heat generating and dissipating elements, reducing thermal contact resistance and ensuring effective heat dissipation even with significant warpage, thereby prolonging the service life of heat dissipating devices.
Implementation Method 1
a thermal conduction sheet, and a heat dissipating device including the thermal conduction sheet
Implementation Method 2
a thermal conduction sheet with graphite particles oriented in the thickness direction, combined with a liquid component
Implementation Method 3
combined with a liquid component, acrylate-based polymer, ethylene-α-olefin copolymer, hot-melt agent, and antioxidant, providing an elastic modulus of 1.4 MPa or less and a tack strength of 5.0 N·mm or higher, ensuring stable adhesion
Data Source
AI summary
A thermal conduction sheet includes graphite particles (A) of at least one kind selected from the group consisting of flake-shaped particles, ellipsoidal particles, and rod-shaped particles. When the graphite particles (A) are flake-shaped particles, a planar direction of the graphite particles (A) is oriented in a thickness direction of the thermal conduction sheet, when the graphite particles (A) are ellipsoidal particles, a major axis direction of the graphite particles (A) is oriented in the thickness direction of the thermal conduction sheet, when the graphite particles (A) are rod-like particles, a longitudinal direction of the graphite particles (A) is oriented in the thickness direction of the thermal conduction sheet, the thermal conduction sheet has an elastic modulus of 1.4 MPa or less under a compression stress of 0.1 MPa at 150° C., and the thermal conduction sheet has a tack strength of 5.0 N·mm or higher at 25° C.