Numerical Analysis of Printed Circuit Board with Thermal Vias: Heat Transfer Characteristics under Nonisothermal Boundary Conditions
ABSTRACT
A thermal via has been used to enhance the heat transfer through the printed circuit board (PCB). Because the thermal
conductivity of a dielectric material is very low, the array of metal vias is placed to make thermal paths in the PCB.
This paper describes the numerical analysis of the PCB having metal vias and focuses on the heat transfer characteristics
under the nonisothermal boundary conditions. The mathematical model of the PCB has the metal vias between two
metal sheets. Under 2nd and 3rd kinds of boundary conditions, the temperature distribution is obtained numerically by
changing the design parameters. The discussion is also made on the effective thermal conductivity of the PCB. In industry,
the use of effective thermal conductivity is convenient for thermal engineers because it simplifies the calculation
process, that is, the composite board can be modeled as a homogeneous medium. From the numerical results, it is confirmed
that the placement of metal sheets and the population of metal vias are important factors to dominate the heat
transfer characteristics of the PCB. It is also shown that although the nonisothermal boundary conditions are applied at
the boundary surface, the temperature difference between the heated and the cooled section is almost uniform when the
metal vias are populated densely with the metal sheets. In this case, the effective thermal conductivity of the PCB is
found to be the same irrespective of the boundary conditions, that is, whether the isothermal or the nonisothermal
boundary conditions are applied.
A thermal via has been used to enhance the heat transfer through the printed circuit board (PCB). Because the thermal
conductivity of a dielectric material is very low, the array of metal vias is placed to make thermal paths in the PCB.
This paper describes the numerical analysis of the PCB having metal vias and focuses on the heat transfer characteristics
under the nonisothermal boundary conditions. The mathematical model of the PCB has the metal vias between two
metal sheets. Under 2nd and 3rd kinds of boundary conditions, the temperature distribution is obtained numerically by
changing the design parameters. The discussion is also made on the effective thermal conductivity of the PCB. In industry,
the use of effective thermal conductivity is convenient for thermal engineers because it simplifies the calculation
process, that is, the composite board can be modeled as a homogeneous medium. From the numerical results, it is confirmed
that the placement of metal sheets and the population of metal vias are important factors to dominate the heat
transfer characteristics of the PCB. It is also shown that although the nonisothermal boundary conditions are applied at
the boundary surface, the temperature difference between the heated and the cooled section is almost uniform when the
metal vias are populated densely with the metal sheets. In this case, the effective thermal conductivity of the PCB is
found to be the same irrespective of the boundary conditions, that is, whether the isothermal or the nonisothermal
boundary conditions are applied.
Cite this paper
Koito, Y. , Kubo, Y. and Tomimura, T. (2013) Numerical Analysis of Printed Circuit Board with Thermal Vias: Heat Transfer Characteristics under Nonisothermal Boundary Conditions. Journal of Electronics Cooling and Thermal Control, 3, 136-143. doi: 10.4236/jectc.2013.34015.
Koito, Y. , Kubo, Y. and Tomimura, T. (2013) Numerical Analysis of Printed Circuit Board with Thermal Vias: Heat Transfer Characteristics under Nonisothermal Boundary Conditions. Journal of Electronics Cooling and Thermal Control, 3, 136-143. doi: 10.4236/jectc.2013.34015.
References
[1] S. Lee, T. F. Lemczyk and M. M. Yovanovich, “Analysis of Thermal Vias in High Density Interconnect Technology,” Proceedings of the 8th Annual IEEE Semiconductor Thermal Measurement and Management Symposium (SE- MI-THERM), Austin, 3-5 February 1992, pp. 55-61. http://dx.doi.org/10.1109/STHERM.1992.172851 [2] W. Nakayama, “Heat Conduction in Printed Circuit Boards: A Mesoscale Modeling Approach,” ASME Journal of Electronic Packaging, Vol. 130, No. 4, 2008, Article ID: 041106. http://dx.doi.org/10.1115/1.2993126 [3] R. S. Li, “Optimization of Thermal Via Design Parameters Based on an Analytical Thermal Resistance Model,” Proceedings of the 6th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm’98), Seattle, 27-30 May 1998, pp. 475-480. http://dx.doi.org/10.1109/ITHERM.1998.689605 [4] T. Hatakeyama, M. Ishizuka, S. Nakagawa and S. Takakuwa, “Thermal Resistance Measurement and Thermal Network Analysis of Printed Circuit Board with Thermal Vias,” Proceedings of the ASME 2011 Pacific Rim Technical Conference & Exposition on Packaging and Integration of Electronic and Photonic Systems (InterPACK 2011), Portland, 6-8 July 2011, Article ID: 52168. [5] B. Guenin, “Thermal Vias—A Packaging Engineer’s Best Friend,” Electronics Cooling, 2004. http://www.electronics-cooling.com/2004/08/thermal-vias-a-packaging-engineers-best-friend/ [6] N. Kafadarova and A. Andonova, “PCB Thermal Design Improvement through Thermal Vias,” Proceedings of the 8th WSEAS International Conference on Circuits, Sys- tems, Electronics, Control & Signal Processing (CSECS ‘09), Puerto De La Cruz, 14-16 December 2009, pp. 241- 244. [7] V. Bissuel, M. Brizoux, A. Grivon, E. Monier-Vinard and F. Pires, “Impact of Printed Circuit Board Via and Micro-Via Structures on Component Thermal Performances,” ASME Journal of Electronic Packaging, Vol. 133, No. 3, 2011, Article ID: 031013. http://dx.doi.org/10.1115/1.4004830 [8] J. R. Culham and M. M. Yovanovich, “Factors Affecting the Calculation of Effective Conductivity in Printed Circuit Boards,” Proceedings of the 6th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm’98), Seattle, 27-30 May 1998, pp. 460-467. http://dx.doi.org/10.1109/ITHERM.1998.689603 [9] Y. Shabany, “Component Size and Effective Thermal Conductivity of Printed Circuit Boards,” Proceedings of the 8th Intersociety Conference on Thermal and Thermo-mechanical Phenomena in Electronic Systems (ITherm 2002), San Diego, 29 May-1 June 2002, pp. 489-494. http://dx.doi.org/10.1109/ITHERM.2002.1012496 [10] W. Nakayama, K. Koizumi, T. Fukue, M. Ishizuka, T. Nakajima, H. Koike and R. Matsuki, “Thermal Characterization of High-Density Interconnects in the Form of Equivalent Thermal Conductivity,” Proceedings of the ASME2009 InterPACK Conference (IPACK2009), San Francisco, 19-23 July 2009, Article ID: 89086. [11] Y. Shabany, “Effects of Boundary Conditions and Source Dimensions on the Effective Thermal Conductivity of a Printed Circuit Board,” Proceedings of IPACK03 International Electronic Packaging Technical Conference and Exhibition, Maui, 6-11 July 2003, Article ID: 35201.
[1] S. Lee, T. F. Lemczyk and M. M. Yovanovich, “Analysis of Thermal Vias in High Density Interconnect Technology,” Proceedings of the 8th Annual IEEE Semiconductor Thermal Measurement and Management Symposium (SE- MI-THERM), Austin, 3-5 February 1992, pp. 55-61. http://dx.doi.org/10.1109/STHERM.1992.172851 [2] W. Nakayama, “Heat Conduction in Printed Circuit Boards: A Mesoscale Modeling Approach,” ASME Journal of Electronic Packaging, Vol. 130, No. 4, 2008, Article ID: 041106. http://dx.doi.org/10.1115/1.2993126 [3] R. S. Li, “Optimization of Thermal Via Design Parameters Based on an Analytical Thermal Resistance Model,” Proceedings of the 6th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm’98), Seattle, 27-30 May 1998, pp. 475-480. http://dx.doi.org/10.1109/ITHERM.1998.689605 [4] T. Hatakeyama, M. Ishizuka, S. Nakagawa and S. Takakuwa, “Thermal Resistance Measurement and Thermal Network Analysis of Printed Circuit Board with Thermal Vias,” Proceedings of the ASME 2011 Pacific Rim Technical Conference & Exposition on Packaging and Integration of Electronic and Photonic Systems (InterPACK 2011), Portland, 6-8 July 2011, Article ID: 52168. [5] B. Guenin, “Thermal Vias—A Packaging Engineer’s Best Friend,” Electronics Cooling, 2004. http://www.electronics-cooling.com/2004/08/thermal-vias-a-packaging-engineers-best-friend/ [6] N. Kafadarova and A. Andonova, “PCB Thermal Design Improvement through Thermal Vias,” Proceedings of the 8th WSEAS International Conference on Circuits, Sys- tems, Electronics, Control & Signal Processing (CSECS ‘09), Puerto De La Cruz, 14-16 December 2009, pp. 241- 244. [7] V. Bissuel, M. Brizoux, A. Grivon, E. Monier-Vinard and F. Pires, “Impact of Printed Circuit Board Via and Micro-Via Structures on Component Thermal Performances,” ASME Journal of Electronic Packaging, Vol. 133, No. 3, 2011, Article ID: 031013. http://dx.doi.org/10.1115/1.4004830 [8] J. R. Culham and M. M. Yovanovich, “Factors Affecting the Calculation of Effective Conductivity in Printed Circuit Boards,” Proceedings of the 6th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm’98), Seattle, 27-30 May 1998, pp. 460-467. http://dx.doi.org/10.1109/ITHERM.1998.689603 [9] Y. Shabany, “Component Size and Effective Thermal Conductivity of Printed Circuit Boards,” Proceedings of the 8th Intersociety Conference on Thermal and Thermo-mechanical Phenomena in Electronic Systems (ITherm 2002), San Diego, 29 May-1 June 2002, pp. 489-494. http://dx.doi.org/10.1109/ITHERM.2002.1012496 [10] W. Nakayama, K. Koizumi, T. Fukue, M. Ishizuka, T. Nakajima, H. Koike and R. Matsuki, “Thermal Characterization of High-Density Interconnects in the Form of Equivalent Thermal Conductivity,” Proceedings of the ASME2009 InterPACK Conference (IPACK2009), San Francisco, 19-23 July 2009, Article ID: 89086. [11] Y. Shabany, “Effects of Boundary Conditions and Source Dimensions on the Effective Thermal Conductivity of a Printed Circuit Board,” Proceedings of IPACK03 International Electronic Packaging Technical Conference and Exhibition, Maui, 6-11 July 2003, Article ID: 35201.