STUDIES ON INFLUENCE OF ANISOTROPIC THERMAL CONDUCTIVITY OF PRINTED CIRCUIT BOARD ON HEAT TRANSFER DURING ELECTRONIC COOLING

2018 ◽  
Author(s):  
Niju Mohammed K ◽  
Samarjeet Chanda ◽  
S.P. Venkateshan ◽  
Sateesh Gedupudi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Printed Circuit Board ◽  
Electronic Cooling ◽  
Circuit Board ◽  
Printed Circuit ◽  
Anisotropic Thermal Conductivity

Evaluation of Effective Thermal Conductivity of Multilayer Printed Circuit Board

2011 ◽  
Author(s):  
Toshio Tomimura ◽  
Yoshihiro Shiotsu ◽  
Yasushi Koito ◽  
Masaru Ishizuka ◽  
Tomoyuki Hatakeyama
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Printed Circuit Board ◽  
Evaluation Method ◽  
Circuit Board ◽  
Printed Circuit ◽  
Plane Direction ◽  
Simple Evaluation

To perform a rational thermal design of a printed circuit board (PCB) with highly anisotropic heat transfer nature in its initial stage, effective thermal conductivities in thickness direction and in in-plane direction must be given depending on the electric circuit of the board. However, a simple evaluation method for the effective thermal conductivities of such PCB has not been developed yet. In this study, as the first step to propose a simple evaluation method, the heat transfer coefficient by natural convection around a horizontal disk, which is indispensable for measuring the effective thermal conductivity, has been evaluated. Furthermore, the thermal conductivity of the glass epoxy resin in in-plane direction has been evaluated by applying the evaluated heat transfer coefficient, and then, the validity of the proposed thermal conductivity measurements of the anisotropic PCB has been confirmed.

Numerical Simulation of Conjugate Heat Transfer From Multiple Electronic Module Packages Cooled by Air

2003 ◽  
Author(s):  
Hideo Yoshino ◽  
Motoo Fujii ◽  
Xing Zhang ◽  
Masud Behnia
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Numerical Simulation ◽  
Conjugate Heat Transfer ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Heat Transfer Area ◽  
Printed Circuit ◽  
Effective Heat ◽  
Parallel Arrangement

This paper reports on the numerical simulation of conjugate heat transfer from multiple electronic module packages (45 × 45 × 2.4 mm) on a printed circuit board placed in a duct. The dimensions of the modules are the same as a single module package previously studied. In the series arrangement, two module packages are installed on the center of the printed circuit board along the airflow direction. In the parallel arrangement, two and/or four module packages are installed normal to the airflow direction. In the numerical simulations, the interval between the module packages was varied and three values were considered (45, 22.5 and 9 mm). The variation of the printed circuit board thermal conductivity was also considered and 0.3, 3 and 20 W/m/K were used with the mean velocity in the duct also at three different values (0.33, 0.67 and 1 m/s). In order to derive a non-dimensional correlation from the numerical results, the concept of the effective heat transfer area previously used for a single module package was used for the multiple module packages. For the series arrangement, the effects of the interval on the effective heat transfer area are relatively low, and the numerical results can be summarized with the same correlation obtained from the single module package. On the other hand, the effective heat transfer area for the parallel arrangement is strongly affected by the parallel interval and the thermal conductivity of printed circuit board. When the interval increases, the temperature of the module packages greatly reduces as the thermal conductivity of the printed circuit board increases.

Computational Modeling of Anisotropic Thermal Conductivity and Joule Heating on Printed Circuit Boards

2011 ◽  
Author(s):  
M. Baris Dogruoz ◽  
Gokul Shankaran ◽  
Gregory Pitner ◽  
Manoj Nagulapally
Keyword(s):  
Thermal Conductivity ◽  
Joule Heating ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Dielectric Material ◽  
Circuit Board ◽  
System Level ◽  
Field Equations ◽  
Printed Circuit ◽  
Anisotropic Thermal Conductivity

A printed circuit board (PCB) consists of consecutive layers of dielectric material and current carrying traces and vias. Conducting system level simulations of PCB’s with detailed trace and via geometries is computationally very expensive. In the present study, the effects of the trace and via geometry in the physical model are taken into account by importing the corresponding ECAD data with which locally varying anisotrpoic thermal conductivity on the PCB is determined accordingly. Moreover, the effects of Joule heating in the current carrying traces are included by using a number of planar heat sources representing individual metal trace layers. The powermap on each of these layers is determined by solving the relevant electric field equations where the temperature dependency of the electrical field is also taken into account. The results are presented on a sample PCB and comparisons are made with the previous studies and conventional models. It is demonstrated that temperature values differ substantially depending on the method of Joule heating treatment used.

Separation of Natural Convection and Radiation by Changing Rotational Acceleration

Volume 1 ◽  
2004 ◽  
Author(s):  
Arnout Willockx ◽  
Gilbert De Mey ◽  
Michel De Paepe ◽  
Boguslaw Wiecek ◽  
Mariusz Felczak ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Centripetal Force ◽  
Rotational Acceleration ◽  
Governing Equations ◽  
Total Heat Transfer ◽  
Closed Cavity ◽  
Printed Circuit

The objective is to separate natural convection and radiation experimentally. Therefore a heat source is placed inside a closed cavity and the acceleration inside the cavity can be changed. A centrifuge is used to change the acceleration. A flat resistor etched on a printed circuit board of 10mm × 48mm, is placed in a hermetically sealed cylinder, which hangs under the arm of the centrifuge. The resistor is powered by a battery, dissipates 0,35W and has a surface temperature of 60°C at 1g. Natural convection is maintained inside the cylinder. Conduction is reduced to a negligible amount by construction of the experiment, thus convection and radiation are the main modes of heat transfer. The rotational speed of the centrifuge determines the centrifugal force in the cylinder. When the centripetal force increases, the temperature of the resistor decreases due to the increase of natural convection. The amount of radiation and total heat transfer can be determined from the experiment, so the amount of natural convection can also be determined. The experimental results are compared with the governing equations to validate the experiment. The reproducibility of the experiment is also checked.

Thermal Performance of Microelectronic Substrates With Submillimeter Integrated Vapor Chamber

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Sangbeom Cho ◽  
Yogendra Joshi
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Printed Circuit Board ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Circuit Board ◽  
Working Fluid ◽  
Vapor Chamber ◽  
Conduction Model ◽  
Printed Circuit

We develop a vapor chamber integrated with a microelectronic packaging substrate and characterize its heat transfer performance. A prototype of vapor chamber integrated printed circuit board (PCB) is fabricated through successful completion of the following tasks: patterning copper micropillar wick structures on PCB, mechanical design and fabrication of condenser, device sealing, and device vacuuming and charging with working fluid. Two prototype vapor chambers with distinct micropillar array designs are fabricated, and their thermal performance tested under various heat inputs supplied from a 2 mm × 2 mm heat source. Thermal performance of the device improves with heat inputs, with the maximum performance of ∼20% over copper plated PCB with the same thickness. A three-dimensional computational fluid dynamics/heat transfer (CFD/HT) numerical model of the vapor chamber, coupled with the conduction model of the packaging substrate is developed, and the results are compared with test data.

Studying heat transfer on inclined printed circuit boards during vapour phase soldering

2017 ◽  
Vol 29 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Attila Geczy ◽  
Daniel Nagy ◽  
Balazs Illes ◽  
Laszlo Fazekas ◽  
Oliver Krammer ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Vapour Phase ◽  
Circuit Board ◽  
Efficient Production ◽  
Content Type ◽  
Printed Circuit ◽  
Heat Transfer Efficiency ◽  
Uneven Heating

Purpose The paper aims to present an investigation of heating during vapour phase soldering (VPS) on inclined printed circuit board (PCB) substrates. The PCB is a horizontal rectangular plate from the aspect of filmwise condensation with a given inclination setting. Design/methodology/approach The paper focuses on the measurement of temperature distribution on the PCBs with a novel setup immersed in the saturated vapour space. The measuring instrumentation is optimized to avoid and minimize vapour perturbing effects. Findings The inhomogeneity of the heating is presented according to the lateral dimensions of the PCB. The inclination improves temperature uniformity, improves heat transfer efficiency; however, a minor misalignment may affect the flow and result in uneven heating. Practical implications The results can be implemented for practical improvements in industrial ovens with the use of intended inclination. The improvements may consequently point to more efficient production and better joint quality. Originality/value The novel method can be used for deeper investigation of inclination during and can be complemented with numerical calculations. The results highlight the importance of precise PCB holding instrumentation in VPS ovens.

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