Design and Optimization of a Composite Heat Spreader to Improve the Thermal Management of a 3D Integrated Circuit

2021 ◽  
Author(s):  
Andisheh Tavakoli ◽  
Kambiz Vafai
Keyword(s):  
Thermal Conductivity ◽  
Heat Sink ◽  
Variable Temperature ◽  
Heat Removal ◽  
High Conductivity ◽  
High Thermal Conductivity ◽  
Maximum Temperature ◽  
Optimal Distribution ◽  
Heat Spreader ◽  
The Impact

Abstract The present study analyzes the optimal distribution of a limited amount of high thermal conductivity material to enhance the heat removal of circular 3D integrated circuits, IC. The structure of the heat spreader is designed as a composite of high thermal conductivity (Boron Arsenide) and moderate thermal conductivity (copper) materials. The volume ratio of high-conductivity inserts to the total volume of the spreader is set at a fixed pertinent ratio. Two different boundary conditions of constant and variable temperature are considered for the heat sink. To examine the impact of adding high-conductivity inserts on the cooling performance of the heat spreader, various patterns of the single and double ring inserts are studied. A parametric study is performed to find the optimal location of the rings. Moreover, the optimal distribution of the high-conductivity material between the inner and outer rings is found. The results show that for the optimal conditions, the maximum temperature of the 3D IC is reduced up to 10%; while the size of the heat sink, and heat spreader can be diminished by as much as 200%.

Constructal Design of Y-Shaped Conductive Pathways for Cooling a Heat-Generating Body

2014 ◽  
Vol 348 ◽  
pp. 245-260 ◽  
Author(s):  
Cristina dos Santos Horbach ◽  
Elizaldo Domingues dos Santos ◽  
Liércio André Isoldi ◽  
Luiz Alberto Oliveira Rocha
Keyword(s):  
Thermal Conductivity ◽  
Temperature Field ◽  
Thermal Performance ◽  
Hot Spots ◽  
Finite Size ◽  
High Conductivity ◽  
High Thermal Conductivity ◽  
Optimal Distribution ◽  
Constructal Design ◽  
Optimal Geometry

This paper applies constructal design to obtain numerically the configuration that facilitates the access of the heat that flows through Y-shaped pathways of a high-conductivity material embedded within a square-shaped heat-generating medium of low-conductivity to cooling this finite-size volume. The objective is to minimize the maximal excess of temperature of the whole system, i.e., the hot spots, independent of where they are located. The total volume and the volume of the material of high thermal conductivity are fixed. Results show that there is no universal optimal geometry for the Y-shaped pathways for every value of high conductivity investigated here. For small values of high thermal conductivity material the best shape presented a well defined format of Y. However, for larger values of high thermal conductivity the best geometry tends to a V-shaped (i.e., the length of stem is suppressed and the bifurcated branches penetrates deeply the heat-generating body towards the superior corners). A comparison between the Y-shaped pathway configuration with a simpler I-shaped blade and with X-shaped configuration was also performed. For constant values of area fraction occupied with a high-conductivity material and the ratio between the high thermal conductivity material and low conductivity of the heat-generating body (φ = 0.1 and = 100) the Y-shaped pathways performed 46% and 13% better when compared to I-shaped and X-shaped pathway configuration, respectively. The best thermal performance is obtained when the highest temperatures (hot spots) are better distributed in the temperature field, i.e., according to the constructal principle of optimal distribution of imperfections.

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

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000062-000066 ◽  
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.

Challenges in Package Cooling of High Performance Servers

2007 ◽  
Author(s):  
Jie Wei
Keyword(s):  
Thermal Conductivity ◽  
Power Dissipation ◽  
High Performance ◽  
Heat Pipes ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Heat Spreader ◽  
Asymmetric Power ◽  
Heat Spreading ◽  
Silver Composite

Cooling technologies for dealing with high-density and asymmetric power dissipation are discussed, arising from thermal management of high performance server CPU-packages. In this paper, investigation and development of associated technologies are introduced from a viewpoint of industrial application, and attention is focused on heat conduction and removal at the package and heatsink module level. Based on analyses of power dissipation and package cooling characteristics, properties of a new metallic thermal interface material are presented where the Indium-Silver composite was evaluated for integrating the chip and its heat-spreader, effects of heat spreading materials on package thermal performance are investigated including high thermal conductivity diamond composites, and evaluations of enhanced heatsink cooling capability are illustrated where high thermal conductivity devices of heat pipes or vapor chambers were applied for improving heat spreading in the heatsink base.

Thermal Enhancement of an LED Light Engine for Automotive Exterior Lighting With Advanced Heat Spreader Technology

2016 ◽  
Author(s):  
Umut Zeynep Uras ◽  
Enes Tamdoğan ◽  
Mehmet Arık
Keyword(s):  
Thermal Conductivity ◽  
Numerical Models ◽  
Maximum Temperature ◽  
Vapor Chamber ◽  
Metal Core ◽  
Heat Spreader ◽  
Printed Circuit ◽  
Thermal Enhancement ◽  
Wide Range ◽  
Light Engine

In recent years, light emitting diodes (LEDs) have become an attractive technology for general and automotive illumination systems. LEDs have been preferable for automobile lighting due to its numerous advantages such as long life, low power consumption, optical control and light quality as well as robustness for high vibration. Thermal management is one of the main issues due to severe ambient conditions and compact volume. Conventionally, tightly packaged double sided FR4 based printed circuit boards are utilized for both driver electronics components and LEDs. In fact, this approach will be a leading trend for advanced Internet of Things (IOT) applications in near future. A series of numerical models are developed to determine the local temperature distribution on both sides of a light engine. Results showed that FR4 PCB has a temperature gradient of over 63°C while the maximum temperature is 105°C. This causes a significant degradation of lifetime and lumen extraction as many LEDs are recommended to be operated below 100°C. In addition to FR4, Aluminum metal core and vapor chamber based advanced heat spreader substrates are developed to obtain thermal impact on the substrate due to a wide range of thermal conductivity of three boards. To mimic real application, two special flex circuits are developed for LEDs and driver circuit. 10 red and 6 amber LEDs at one flex-PCB, and driver components are populated on the other flex-PCB are mounted. Both flex circuits are attached each side of the substrate. Experimental results showed that the local hotspots occurred at FR4 PCB due to low thermal conductivity. Later, a metal core printed circuit board is investigated to minimalize local hot spots. High conductivity metal core PCB showed a 19.9% improvement over FR4 based board. A further study has been performed with an advanced heat spreader based on vapor chamber technology. Results showed that a thermal enhancement of 7.4% and 25.8% over Al metal core and FR4 based boards with an advanced vapor chamber substrate.

Introduce a novel configurationof microchannel andhigh-conductivity insertsfor cooling of disc-shaped electronic components

2019 ◽  
Vol 30 (6) ◽  
pp. 2845-2859 ◽  
Author(s):  
Reza Dadsetani ◽  
Ghanbar Ali Sheikhzadeh ◽  
Mohammad Reza Hajmohammadi ◽  
Mohammad Reza Safaei
Keyword(s):  
Thermal Conductivity ◽  
Hybrid Method ◽  
High Thermal Conductivity ◽  
Maximum Temperature ◽  
Thermal Conductivity Ratio ◽  
Conductivity Ratio ◽  
Electronic Components ◽  
Content Type ◽  
Micro Pump ◽  
Hybrid Configuration

Purpose Electronic components’ efficiency is the cornerstone of technology progress. The cooling process used for electronic components plays a main role in their performance. Embedded high-conductivity material and provided microchannel heat sink are two common cooling methods. The former is expensive to implement while the latter needs micro-pump, which consumes energy to circulate the flow. The aim of this study is providing a new configuration and method for improving the performance of electronic components. Design/methodology/approach To manage these challenges and improve the cooling efficiency, a novel method named Hybrid is presented here. Each method's performance has been investigated, and the results are widely compared with others. Considering the micro-pump power, the supply of the microchannel flow and the thermal conductivity ratio (thermal conductivity ratio is defined as the ratio of thermal conductivity of high thermal conductivity material to the thermal conductivity of base solid), the maximum disk temperature of each method was evaluated and compared to others. Findings The results indicated that the Hybrid method can reduce the maximum disk temperature up to 90 per cent compared to the embedded high thermal conductivity at the same thermal conductivity ratio. Moreover, the Hybrid method further reduces the maximum disk temperature up to 75 per cent compared to the microchannel, at equivalent power consumption. Originality/value The information in this research is presented in such a way that designers can choose the desired composition, the limited amount of consumed energy and the high temperature of the component. According to the study of radial-hybrid configuration, the different ratio of microchannel and materials with a high thermal conductivity coefficient in the constant cooling volume was investigated. The goal of the investigation was to decrease the maximum temperature of a plate on constant energy consumption. This aim has been obtained in the radial-hybrid configuration.

scholarly journals Constructal Design of an Arrow-Shaped High Thermal Conductivity Channel in a Square Heat Generation Body

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 475 ◽  
Author(s):  
Fengyin Zhang ◽  
Huijun Feng ◽  
Lingen Chen ◽  
Jiang You ◽  
Zhihui Xie
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Heat Generation ◽  
Degrees Of Freedom ◽  
High Thermal Conductivity ◽  
Maximum Temperature ◽  
Thermal Conductivity Ratio ◽  
Maximum Temperature Difference ◽  
Conduction Model ◽  
Three Degrees Of Freedom

A heat conduction model with an arrow-shaped high thermal conductivity channel (ASHTCC) in a square heat generation body (SHGB) is established in this paper. By taking the minimum maximum temperature difference (MMTD) as the optimization goal, constructal designs of the ASHTCC are conducted based on single, two, and three degrees of freedom optimizations under the condition of fixed ASHTCC material. The outcomes illustrate that the heat conduction performance (HCP) of the SHGB is better when the structure of the ASHTCC tends to be flat. Increasing the thermal conductivity ratio and area fraction of the ASHTCC material can improve the HCP of the SHGB. In the discussed numerical examples, the MMTD obtained by three degrees of freedom optimization are reduced by 8.42% and 4.40%, respectively, compared with those obtained by single and two degrees of freedom optimizations. Therefore, three degrees of freedom optimization can further improve the HCP of the SHGB. Compared the HCPs of the SHGBs with ASHTCC and the T-shaped one, the MMTD of the former is reduced by 13.0%. Thus, the structure of the ASHTCC is proven to be superior to that of the T-shaped one. The optimization results gained in this paper have reference values for the optimal structure designs for the heat dissipations of various electronic devices.

scholarly journals Gallium nitride heterostructure field-effect transistor with a heat-removal system based on a trench in the passivation layer filled by a high thermal conductivity material

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 74-82
Author(s):  
V. S. Volcheck ◽  
V. R. Stempitsky
Keyword(s):  
Thermal Conductivity ◽  
Gallium Nitride ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Heat Removal ◽  
High Thermal Conductivity ◽  
Device Structures ◽  
Effect Transistor ◽  
Heat Removal System ◽  
Removal System

The self-heating effect poses a main problem for high-power electronic and optoelectronic devices based on gallium nitride. A non-uniform distribution of the dissipated power and a rise of the average temperature inside the gallium nitride heterostructure field-effect transistor lead to the formation of a hot spot near the conducting channel and result in the degradation of the drain current, output power and device reliability. The purpose of this work is to develop the design of a gallium nitride heterostructure field-effect transistor with an effective heat-removal system and to study using numerical simulation the thermal phenomena specific to this device. The objects of the research are the device structures formed on sapphire, each of whom features both a graphene heat-eliminating element on its top surface and a trench in the passivation layer filled by a high thermal conductivity material. The subject of the research is the electrical and thermal characteristics of these device structures. The simulation results verify the effectiveness of the integration of the heat-removal system into the gallium nitride heterostructure field-effect transistor that can mitigate the self-heating effect and improve the device performance. The advantage of our concept is that the graphene heat-eliminating element is structurally connected with a heat sink and is designed for removing the heat immediately from the maximum temperature area through the trench in which a high thermal conductivity material is deposited. The results can be used by the electronics industry of the Republic of Belarus for developing the hardware components of gallium nitride power electronics.

scholarly journals Impacto de las variaciones de temperatura diaria en la historia natural de los anuros tropicales

2016 ◽  
Vol 65 (1) ◽  
pp. 55 ◽  
Author(s):  
Manuel Hernando Bernal-Bautista ◽  
Jorge Luis Turriago-González ◽  
Francisco Antonio Villa-Navarro
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Variable Temperature ◽  
Developmental Time ◽  
Maximum Temperature ◽  
Medium Temperature ◽  
Variable Environment ◽  
Gosner Stage ◽  
C 23 ◽  
The Impact

Anuran embryos and tadpoles are daily exposed to wide thermal variations in their ponds, with maximum temperatures at midday. The aim of this research was to study the impact of three daily variable thermal environments (with maximum experimental temperatures between 10:00 and 16:00 hours), on the survival, developmental time and body size of metamorphs of four tropical anuran species from lowland habitats in Colombia. A total of 50 embryos (Gosner stage ten) to metamorphosis (Gosner stage 46) of Rhinella humboldti, Hypsiboas crepitans and Engystomops pustulosus were exposed to each one of the three daily variable temperature treatments: high temperature (mean = 27.5 °C; maximum temperature = 34 ± 1 °C; range = 23-35 °C), medium temperature (25.5 °C; 29 ± 1 °C; 23-30 °C), and low temperature (24 °C; 24 ± 1 °C; 23-25 °C). For the other species, Espadarana prosoblepon, 40 embryos to metamorphosis were exposed to each one of the following thermal treatments: high temperature (mean = 22 °C; maximum temperature = 25 ± 1 °C; range = 18-26 °C), medium temperature (20.5 °C; 22 ± 1 °C; 18-23 °C), and low temperature (19 °C; 19 ± 1 °C; 18-20 °C). For all species, the thermal variable environment with the highest temperature showed the greatest accumulated survival, reduced significantly the developmental time from embryos to metamorphs, and the snout-vent-length of metamorphs. Therefore, under field conditions where ponds are exposed to thermally variable environments, the highest temperatures may promote a decrease in the period of time to metamorphosis, and a positive increase for the anuran survival; nevertheless, extreme temperatures were also found in the microhabitat of the species studied, higher than their upper thermal limits reported, which suggest a vulnerable situation for them and other tropical anurans from similar habitats.

Steady-state heat conduction analysis for two-terminal microwave oscillator devices with rectangular integral heat sinks

1995 ◽  
Vol 451 (1942) ◽  
pp. 375-381 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Steady State ◽  
Temperature Rise ◽  
Heat Sink ◽  
Microwave Oscillator ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Maximum Temperature Rise ◽  
Steady State Heat

The outline of a theoretical analysis to calculate the steady-state temperature distribution within a rectangular prism mounted on a semi-infinite heat sink is presented. The incident heat flux is uniform over a given centralized circular region on one face of the prism. The thermal conductivity of the material is treated as being dependent on the temperature. The model is used to calculate the maximum temperature rise within a heat sink configuration that is used to package contemporary two-terminal microwave oscillator devices. Results are presented that show how the maximum temperature rise within such commercially available heat sink packages depends on the input heat flux and the dimensions and thermal conductivity of the materials. These results are presented in a generalized form for device design purposes.

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