Graphene Based Thermal Conducting Paste and a Standalone Embedded System for Measurement of Thermal Conductivity
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2017-02-28 |
| Journal | International Journal for Research in Applied Science and Engineering Technology |
| Authors | Ankur Jyoti Borthakur |
| Institutions | Sikkim Manipal University |
| Analysis | Full AI Review Included |
As an expert material scientist and technical engineer for 6CCVD, the following documentation analyzes the research into high-performance Thermal Interface Materials (TIMs) and frames it against the superior thermal capabilities of MPCVD Diamond.
Graphene Based Thermal Conducting Paste Analysis & 6CCVD Diamond Solutions
Section titled âGraphene Based Thermal Conducting Paste Analysis & 6CCVD Diamond SolutionsâExecutive Summary
Section titled âExecutive SummaryâThis paper successfully validates the use of high-thermal-conductivity carbon allotropes, specifically Graphene, as a filler material for next-generation thermal interface compounds crucial for high-power semiconductor devices.
- Benchmark Achievement: The optimized Graphene-based thermal paste (Batch C: 40% ZnO2, 22% TE-Graphene) achieved a thermal conductivity ($K$) of 263.96 W/mK.
- Performance Superiority: This Graphene compound demonstrated significantly higher performance than commercial market equivalents (IDL at 122.24 W/mK, Silvo at 67.143 W/mK).
- Application Focus: The research addresses the critical need for advanced TIMs in high-density electronic packages (like CPUs), where shrinking die sizes and increasing power dissipation demand materials far exceeding traditional metal or Boron Nitride fillers.
- Measurement Validation: The standalone embedded measurement system was rigorously validated against a standard Copper test, achieving an error margin of ± 0.96%, confirming the reliability of the thermal data extracted.
- Material Implication: The outstanding performance of the Graphene composite (a form of engineered carbon) confirms the potential for ultra-high thermal management solutions, directly positioning 6CCVD Single Crystal Diamond (SCD) as the ultimate material for high-flux heat spreading and electronic packaging substrates.
Technical Specifications
Section titled âTechnical SpecificationsâHard data extracted from the thermal measurements and system validation parameters.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Graphene Paste $K$ (Batch C) | 263.96 | W/mK | 40% ZnO2 + 22% TE-Graphene |
| Commercial Paste $K$ (IDL) | 122.24 | W/mK | Commercial heat sink compound |
| Commercial Paste $K$ (Silvo) | 67.143 | W/mK | Commercial heat sink compound |
| Standardization Material | Copper (Cu) | N/A | Verification of embedded system |
| Actual $K$ (Copper) | 385 | W/mK | Standard Material |
| Measured $K$ (Copper) | 392 | W/mK | Embedded system output |
| Measurement Error | ± 0.96 | % | System verification accuracy |
| Temperature Sensor Type | K-type | Thermocouple | Used for T1, T2, T3, T4 measurement points |
| Sensor Spacing | 2.5 | cm | Distance between temperature measurement points |
| Maximum Temperature Difference | 117 | °C | Measured $\Delta$T over 1 min (Copper Test) |
| Microcontroller | ATMega328 | N/A | Data logging and system control |
| Input Voltage (MCU) | 1.8 - 5.5 | Volts | Operating voltage range |
Key Methodologies
Section titled âKey MethodologiesâThe experiment utilized a custom-designed standalone embedded system following the principles of Fourierâs Law ($q = KAT$, where $K$ is thermal conductivity).
- Component Integration: A test structure was fabricated using a Micro Ceramic Heater (MCH) to provide uniform heat flux at the initial position (T1).
- Thermal Sensing: Four K-type thermocouples (MAX6675 digitized), labeled T1, T2, T3, and T4, were embedded along the test substance (slide), spaced 2.5 cm apart.
- Data Acquisition: Temperature data from the four sensors, along with elapsed time (ET), were logged onto an ATMega328 Microcontroller and transmitted via a PL2303HX USB to TTL UART converter to a host PC.
- Software Analysis: A dedicated proprietary GUI (Graphical User Interface) developed in Visual Basic automatically imported temperature values to calculate Specific Heat ($C$) and Thermal Conductivity ($K$).
- Standardization: The system functionality was verified by measuring the known thermal conductivity of Copper (Cu) and Aluminium standards, achieving highly acceptable accuracy (error < 1%).
- Material Formulation: Experimental thermal pastes were synthesized by mixing various proportions of TE-Graphene and Zinc Oxide (ZnO2) filler materials into a base matrix of Silicone Grease.
- Thermal Testing: The synthesized thermal pastes were applied as the Thermal Interface Material (TIM) and tested to determine their heat transfer capability and specific thermal conductivity ($K$).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe research highlights the critical importance of carbon materials with exceptional phonon transport characteristics in thermal management applications. The measured performance of the best Graphene batch (263.96 W/mK) confirms Graphene as an excellent thermal filler, but also serves to underscore the vastly superior properties of MPCVD diamond, which 6CCVD provides.
Applicable Materials
Section titled âApplicable MaterialsâFor engineers and researchers seeking to replicate, exceed, or integrate the highest possible thermal performance demonstrated in this paper, 6CCVD offers the following materials:
| Material Type | Recommended Grade | Relevant Application / Benefit |
|---|---|---|
| Optical Grade SCD | SCD (Single Crystal Diamond) | The Benchmark: SCD offers thermal conductivity > 2000 W/mK, far exceeding any reported Graphene paste or metallic filler. Ideal for high-power electronics, laser diode substrates, and RF/microwave devices requiring maximum heat flux dissipation. |
| Electronic Grade PCD | PCD (Polycrystalline Diamond) | Cost-effective alternative for high heat spreading. Available in wafers up to 125 mm, providing large-area coverage for complex heat sink interfaces or hybrid packaging architectures. |
| Ultra-Smooth SCD Plates | High-Polish SCD (Ra < 1 nm) | Perfect substrates for studying TIM contact resistance. The ultra-low surface roughness minimizes air gaps, allowing researchers to isolate and accurately measure the intrinsic thermal performance of thin interface films (like the Graphene paste analyzed). |
Customization Potential
Section titled âCustomization PotentialâReplicating or extending this research into industrial electronic packaging requires precise material engineering, a core capability of 6CCVD:
- Custom Plate Dimensions: While the paper used a small test slide, 6CCVD provides custom diamond wafers and plates up to 125 mm in diameter (PCD), suitable for full-scale CPU/GPU heat spreader designs.
- Precision Thickness Control: We offer SCD and PCD layers ranging from 0.1 ”m (for ultra-thin film studies, relevant to TIM research) up to 500 ”m for robust heat spreaders, allowing precise control over thermal resistance modeling.
- Advanced Metalization Services: For studies requiring integration into an electronic system, 6CCVD provides in-house sputtering and plating of thermal and electrical contacts including Ti, Pt, Au, Pd, W, and Cu. This is critical for creating reliable interfaces between the diamond spreader and the heat sink/CPU package.
- Microfabrication: Custom geometries, including laser cutting and via formation necessary for complex embedded sensor setups (similar to the T1-T4 layout) or micro-heat channels, are available through our specialized engineering services.
Engineering Support
Section titled âEngineering SupportâGraphene-based TIMs represent an excellent step forward, but CVD Diamond provides the required leap for next-generation thermal limitations. 6CCVDâs in-house PhD engineering team can assist with:
- Material Selection: Guiding researchers on selecting the optimal diamond material (SCD vs. PCD, specific grain size) for high-flux semiconductor packaging or advanced thermal analysis systems.
- Modeling and Simulation: Providing material parameters (K values, specific heat) necessary for Finite Element Analysis (FEA) modeling of thermal management solutions in similar high-power computing projects.
- Interface Optimization: Consulting on metalization stack design and polishing specifications to achieve the lowest possible thermal boundary resistance at the diamond-to-silicon or diamond-to-copper interface.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Graphene is an allotrope of carbon which is arranged in a honey-comb lattice structure. It is the basic building block of all other carbon allotropes such as graphite, charcoal, carbon nanotubes and fullerenes. Graphene has many miraculous properties. It is hypothesized to be 100 times stronger than steel and it is the only 2-dimensional substance in the world. The thickness of one layer of Graphene is so negligible i.e. it is just one carbon atom thick and so its single layer is considered to be 2-D. It is nearly transparent and conducts heat and electricity efficiently. This paper is based on exploiting the following properties of graphene: Graphene is the best known thermal conductor. Graphene forms bonds with a huge number of materials at molecular level. Graphene exhibits a variety of properties under the influence of different constraints. Thermal grease (also called CPU grease, heat sink compound, heat sink paste, thermal compound, thermal gel, thermal interface material, thermal paste) is a kind of thermally conductive (but usually electrically insulating) compound, which is commonly used as an interface between heat sinks and heat sources (e.g., high power consuming semiconductor devices). The main purpose of thermal grease is to eliminate air gaps or spaces which turn the junction into a dielectric layer (which act as thermal insulator) from the interface area so as to maximize heat transfer. [1] This Thermal paste/grease we created is comprised of TE-Graphene and ZnO2 (Zinc Oxide) mixed with the base matrix SiliconeGrease where ZnO 2 is the binding agent.The extraordinary thermal conductivity of graphene makes this paste much more efficient than its counterparts which uses filler materials like diamond, silver, Boron Nitride etc.To measure the thermal conductivity of the aforementioned material, we have designed a standalone embedded system to measure its thermal conductivity.This systemâs functionality is verified using the calculation and verification of the thermal conductivity of two standard materials viz.copper and aluminium.