Boron Nitride Heat Dissipation Sheet for Electromagnetic Transparency
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Solution Overview
Problem
Conventional heat dissipation sheets with high thermal conductivity, such as graphite sheets, absorb or reflect electromagnetic waves, compromising communication performance in GHz frequency band applications like autonomous vehicles and portable terminals, where both efficient heat dissipation and electromagnetic wave transmission are required.
Innovation Solution
A sheet layer composed of 5-35 wt% polymer resin and 65-95 wt% flat boron nitride, with specific particle size and orientation, providing horizontal thermal conductivity of 5 W/mK or more, three times that of vertical conductivity, and low loss tangent for efficient heat dissipation and electromagnetic wave transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a graphite sheet is used for heat dissipation, then heat dissipation performance is improved, but electromagnetic wave transmission is blocked due to absorption or reflection
Solution Approach 1:
The patent uses boron nitride particles dispersed in a polymer matrix to create a composite heat dissipation sheet. Boron nitride provides high thermal conductivity and electromagnetic wave transparency, while the polymer matrix provides structural integrity and flexibility. This composite structure achieves both effective heat dissipation and electromagnetic wave transmission without the absorption/reflection problems of graphite sheets.
Solution Approach 2:
The patent optimizes the particle size distribution of boron nitride (D10, D50, D90 parameters) and the polymer content ratio to achieve optimal thermal conductivity and electromagnetic wave transmission. By controlling particle size parameters and composition ratios, the sheet achieves horizontal thermal conductivity of 5 W/mK or more while maintaining low loss tangent for electromagnetic waves.
2Volume of moving object
If the antenna unit is disposed close to the electronic component, then device size is reduced, but communication performance deteriorates due to heat interference and electromagnetic wave blockage
Solution Approach 1:
The boron nitride-polymer composite sheet enables close placement of antenna and electronic components by providing both heat dissipation capability and electromagnetic wave transmission. The composite structure allows thermal energy to conduct through the sheet while electromagnetic waves pass through with minimal loss, resolving the conflict between compact design and communication performance.
Solution Approach 2:
The heat dissipation sheet acts as an intermediary layer between the heat-emitting electronic component and the antenna unit. It conducts heat away from the component while simultaneously allowing electromagnetic waves to pass through to the antenna, enabling close proximity placement without interference.
3Reliability
If the polymer resin content is increased to improve electromagnetic wave transmission, then heat dissipation performance decreases
Solution Approach 1:
The patent optimizes the polymer resin content ratio and boron nitride particle size distribution to achieve the optimal balance between electromagnetic wave transmission and heat dissipation. By precisely controlling these parameters, the sheet achieves both low loss tangent for electromagnetic waves and sufficient thermal conductivity.
Solution Approach 2:
The composite structure allows the polymer matrix to provide electromagnetic wave transparency while the dispersed boron nitride particles provide thermal conductivity pathways. The synergistic combination of these two materials achieves both functions simultaneously without compromising either performance.
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 sheet layer achieves excellent heat dissipation and high electromagnetic wave transmission efficiency, allowing for closer proximity of heat-emitting components to antenna units without impairing communication performance, thus enhancing the design flexibility of communication devices.
Implementation Method 1
the sheet layer has a horizontal thermal conductivity of 5 W/mK or more
Implementation Method 2
high electromagnetic wave transmission efficiency
Data Source
AI summary
The communication module according to one embodiment of the present invention comprises: a printed circuit board; an antenna unit and electronic components arranged on the printed circuit board; and a sheet layer arranged on the antenna unit and the electronic components, wherein the sheet layer comprises 15-35% of a polymer resin and 65-85 wt % of flat boron nitride, the flat boron nitride has an average particle size (D50) of 40 to 50 μm, a D10 of 10 to 25 μm, and a D90 of 75 to 85 μm, and the θ50 of the flat boron nitride is arranged to form an angle of 40° or less with horizontal components of the sheet layer.