Thermal Conductivity and the Cooling Performance of Cu Alloy-Graphite Composite Heat Spreaders Fabricated by the Powder Metallurgy.

In order to solve the problem that low thermal conductivity of the plastics for the heat of LED, SiC/Phenolic resin for the heat of LED were fabricated combining powder metallurgy. The effects of particles diameters, content and adding nanoparticles on thermal conductivity of the fabricated composites were investigated, the mechanical properties were also characterized. The experimental results showed that the materials were obtained, and the insulation performance of the fabricated SiC/Phenolic resin was higher than the industry standard one, the thermal conductivity reached 4.1W/(m·k)-1. And the bending strength of the fabricated composites was up to 68.11MPa. The problem of low thermal conductivity of the material is expected to be solved. In addition, it is meaningful for improving LED life.

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Measurements of Aluminum-Annealed Pyrolytic Graphite Composite Baseplates with Improved Thermal Conductivity

Journal of Manufacturing Engineering ◽

10.37255/jme.v16i2pp042-047 ◽

2021 ◽

Vol 16 (2) ◽

pp. 042-047

Author(s):

Yanfei Bian ◽

SHI Jian-zhou ◽

XIE Ming-jun ◽

CAI Meng

Keyword(s):

Thermal Conductivity ◽

Thermal Properties ◽

Thermal Management ◽

Pure Aluminum ◽

Pyrolytic Graphite ◽

Aluminum Plate ◽

Graphite Composite ◽

Conductive Composites ◽

Thermal Potential ◽

Thermally Conductive

Annealed pyrolytic graphite (APG) is a material with thermal conductivity of about 1500 W/(m·K). This property may enable the usage of APG’s thermal potential to develop highly thermally conductive composites for devices requiring effective thermal management. In this paper, APG has been encapsulated in aluminum by brazing, and the thermal properties of Al-APG composite baseplates were measured. The results show that the thermal conductivity of the Al-APG composite baseplates is about 620 W/(m·K), which is four times higher than the pure aluminum plate (152 W/(m·K)).

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A Novel, Low-Cost C-C Composite Heat Sink Material

MRS Proceedings ◽

10.1557/proc-445-57 ◽

1996 ◽

Vol 445 ◽

Author(s):

W. Kowbel ◽

V. Chellappa ◽

J.C. Withers

Keyword(s):

Thermal Conductivity ◽

Heat Sink ◽

Low Cost ◽

Mechanical And Thermal Properties ◽

New Class ◽

Dielectric Coatings ◽

Potential Applications ◽

New Material ◽

New Type ◽

Composite Heat

AbstractRapid advances in high power electronics packaging require the development of new heat sink materials. Advanced composites designed to provide thermal expansion control as well as improved thermal conductivity have the potential to provide benefits in the removal of excess heat from electronic devices. Carbon-carbon (C-C) composits are under consideration for several military and space electronic applications including SEM-E electronic boxes. The high cost of C-C composits has greatly hindered their wide spread commercialization. A new manufacturing process has been developed to produce high thermal conductivity (over 400 W/mK) C-C composites at greatly reduced cost (less than $50/lb). This new material has potential applications as both a heat sink and a substrate. Dielectric coatings such as A1N and diamond were applied to this new type of heat sink material. Processing, as well as mechanical and thermal properties of this new class of heat sink material will be presented.

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Preparation of Cu-Cr-Zr/AlN Nanocomposites and their Mechanical and Conductive Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.2756 ◽

2011 ◽

Vol 239-242 ◽

pp. 2756-2759

Author(s):

Yong Qiang Qin ◽

Yu Cheng Wu ◽

Yan Wang ◽

Yu Hong ◽

Jing Quan Deng ◽

...

Keyword(s):

Thermal Conductivity ◽

Wear Resistance ◽

High Temperature ◽

Powder Metallurgy ◽

Mechanical Alloying ◽

Room Temperature ◽

Copper Alloys ◽

Morphology Characterization ◽

Conductive Properties ◽

Conductivity Behavior

Copper and copper alloys had various applications in tremendous areas due to their unique properties, such as good conductivity, good thermal conductivity and so on. However, applications of copper and copper alloys were severely restricted as the result of the limited strength at room temperature and poor wear-resistance at high temperature. In this paper, we investigated the preparation of Cu-Cr-Zr/AlN nanocomposites by mechanical alloying process and then powder metallurgy technology. XRD and SEM were performed for the phase and morphology characterization. The conductivity properties were also tested and the results showed that Cu-Cr-Zr/AlN nanocomposites exhibited excellent conductivity behavior.

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Efficient Thermal Analysis of Lab-Grown Diamond Heat Spreaders

10.1115/ipack2021-73017 ◽

2021 ◽

Author(s):

Zihao Yuan ◽

Tao Zhang ◽

Jeroen Van Duren ◽

Ayse K. Coskun

Keyword(s):

Steady State ◽

Real World ◽

High Performance ◽

Silicon Layer ◽

Maximum Temperature ◽

Cooling Performance ◽

Thermal Models ◽

Heat Spreaders ◽

Transient Simulations ◽

Transient Thermal

Abstract Lab-grown diamond heat spreaders are becoming attractive solutions compared to traditional copper heat spreaders due to their high thermal conductivity, the ability to directly bond them on silicon, and allow for an ultra-thin silicon layer. Researchers have developed various thermal models and prototypes of lab-grown diamond heat spreaders to evaluate their cooling performance and heat spreading ability. The majority of existing thermal models are built using finite-element method (FEM) based simulators such as COMSOL and ANSYS. However, such commercial simulators are computationally expensive and lead to long solution times along with large memory requirements. These limitations make commercial simulators unsuitable for evaluating numerous design alternatives or runtime scenarios for real-world high-performance processors. Because of this modeling challenge, none of the existing works have evaluated the thermal behavior of lab-grown diamond heat spreaders on real-world high-performance processors running realistic application benchmarks. Recently, we have developed a parallel compact thermal simulator, PACT, that is able to carry out fast and accurate steady-state and transient thermal simulations and can be extended to support emerging integration and cooling technologies. In this paper, we use PACT to evaluate the steady-state and transient cooling performance of lab-grown diamond heat spreaders against traditional copper heat spreaders on various real-world high-performance processors (e.g., Intel i7 6950X, IBM Power9, and PicoSoC). By using PACT with architectural performance and power simulators such as Sniper and McPAT, we are able to run transient simulations with realistic benchmarks. Simulation results show that lab-grown diamond heat spreaders achieve maximum temperature and thermal gradient reductions of up to 26.73 °C and 13.75 °C when compared to traditional copper heat spreaders, respectively. The maximum steady-state and transient simulation times of PACT for the real-world high-performance chips and realistic applications used in our experiments are 259 s and 22 min, respectively.

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Integration of Silver Heat Spreaders in LTCC utilizing Thick Silver Tape in the Co-fire Process

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/cicmt-tp13 ◽

2015 ◽

Vol 2015 (CICMT) ◽

pp. 000062-000066 ◽

Cited By ~ 1

Author(s):

T. Welker ◽

S. Günschmann ◽

N. Gutzeit ◽

J. Müller

Keyword(s):

Thermal Conductivity ◽

Thermal Resistance ◽

Heat Sink ◽

Junction Temperature ◽

Large Area ◽

Heat Spreader ◽

Integration Density ◽

Heat Spreaders ◽

Cte Mismatch ◽

Pattern Resolution

The integration density in semiconductor devices is significantly increased in the last years. This trend is already described by Moore's law what forecasts a doubling of the integration density every two years. This evolution makes greater demands on the substrate technology which is used for the first level interconnect between the semiconductor and the device package. Higher pattern resolution is required to connect more functions on a smaller chip. Also the thermal performance of the substrate is a crucial issue. The increased integration density leads to an increased power density, what means that more heat has to dissipate on a smaller area. Thus, substrates with a high thermal conductivity (e. g. direct bonded copper (DBC)) are utilized which spread the heat over a large area. However, the reduced pattern resolution caused by thick metal layers is disadvantageous for this substrate technology. Alternatively, low temperature co-fired ceramic (LTCC) can be used. This multilayer technology provides a high pattern resolution in combination with a high integration grade. The poor thermal conductivity of LTCC (3 … 5 W*m−1*K−1) requires thermal vias made of silver paste which are placed between the power chip and the heat sink and reduce the thermal resistance of the substrate. The via-pitch and diameter is limited by the LTCC technology, what allows a maximum filling grade of approx. 20 to 25 %. Alternatively, an opening in the ceramic is created, to bond the chip directly to the heat sink. This leads to technological challenges like the CTE mismatch between the chip and the heat sink material. Expensive materials like copper molybdenum composites with matched CTE have to be used. In the presented investigation, a thick silver tape is used to form a thick silver heat spreader through the LTCC substrate. An opening is structured by laser cutting in the LTCC tape and filled with a laser cut silver tape. After lamination, the substrate is fired using a constraint sintering process. The bond strength of the silver to LTCC interface is approx. 5.6 MPa. The thermal resistance of the silver structure is measured by a thermal test chip (Delphi PST1, 2.5 mm × 2.5 mm) glued with a high thermal conducting epoxy to the silver structure. The chip contains a resistor and diodes to generate heat and to determine the junction temperature respectively. The backside of the test structure is temperature stabilized by a temperature controlled heat sink. The resulting thermal resistance is in the range of 1.1 K/W to 1.5 K/W depending on the length of silver structure (5 mm to 7 mm). Advantages of the presented heat spreader are the low thermal resistance and the good embedding capability in the co-fire LTCC process.

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