![Sample our Engineering & Technology journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5933/TOC-Subject-Sample-2021-Engineering-Tech.jpg"})
ABSTRACT
Thermal management is one of the main issues for electronics cooling especially for tightly packaged PCBs that experience local heat generation. Thus, theoretical and experimental investigations have been conducted to predict thermal performance of a novel heat-pipe-embedded-PCB. First, plain heat-pipe is experimentally tested under various inclination angles and validated by theoretical and numerical calculations. Flattened heat-pipes have been embedded into PCB prototypes made of polymer and aluminum and have been tested for similar experimental parameters; they have shown a decrease in compared with conventional heat pipe. Accordingly, reduction of
approximately 50% is achieved for both embedded PCB prototypes.
Acknowledgements
The funding for this project was provided by the Turkish Ministry of Science and Technology under the grant number 01464.STZ.2012-2. This work was supported by the Istanbul Development Agency under the contract number ISTKABIL26 and ISTKATR10/15/YNK/0029. The authors would like to thank FARBA Corporation for their support in building the experimental setup.
Nomenclature
| A | = | surface area, (m2) |
| d | = | diameter, (m) |
| g | = | gravity, (m/s2) |
| h | = | heat transfer cofficient, (W/m2 ·K) |
| hfg | = | enthalpy of vaporization, (J/kg) |
| K | = | permeability |
| L | = | length, (m) |
| = | mass flow rate, (kg/s) | |
| P | = | pressure, (Pa) |
| q | = | total heat transport, (W) |
| = | energy, (J/s) | |
| r | = | radius, (m) |
| R | = | thermal resistance, (oC/W) |
| rn | = | radius of the nucleation |
| T | = | temperature, (oC) |
Dimensionless groups
| f | = | friction factor |
| Nu | = | Nusselt number |
| Pr | = | Prandtl number |
| Ra | = | Rayleigh number |
Greek Symbols
| Δp | = | Pressure difference, (Pa) |
| α | = | diffusivity, (m2/s) |
| ε | = | emissivity of the surface |
| ∞ | = | infinite |
| K | = | thermal conductivity, (W/m·K) |
| μ | = | Dynamic viscosity, (kg/m·s) |
| ν | = | kinematic viscosity, (m2/s) |
| ψ | = | Axial angle |
| θ | = | surface angle, (rad) |
| ρ | = | density, (kg/m3) |
| σ | = | surface tension, (N/m) |
Subscripts
| a | = | adiabatic |
| b | = | boiling |
| cap | = | capillary |
| c | = | condenser |
| conv | = | convection |
| eff | = | effective |
| e | = | evaporator |
| en | = | entrainment |
| EES | = | engineering equation solver |
| h | = | hydrostatic |
| HP | = | heat pipe |
| i | = | inner |
| l | = | liquid |
| v | = | vapour |
| rad | = | radiation |
| So | = | sonic |
| Surr | = | surrounding |
| O | = | outside |
| PSB | = | printed circuit board |
| wi | = | wick |