Full Content is available to subscribers

Subscribe/Learn More  >

System Level Thermal Optimization of an Automotive Lightning Module Incorporating Several Power Devices

[+] Author Affiliations
Victor Chiriac, Tien-Yu Tom Lee

Freescale Semiconductor, Inc., Tempe, AZ

Paper No. IPACK2007-33707, pp. 241-247; 7 pages
  • ASME 2007 InterPACK Conference collocated with the ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference
  • ASME 2007 InterPACK Conference, Volume 1
  • Vancouver, British Columbia, Canada, July 8–12, 2007
  • Conference Sponsors: Electronic and Photonic Packaging Division
  • ISBN: 0-7918-4277-0 | eISBN: 0-7918-3801-3
  • Copyright © 2007 by ASME


The conjugate thermal performance of microelectronics module incorporating several power packages and additional passive components in a custom environment is evaluated and further optimized using numerical simulation and experimental validation. The automotive industry deals on a daily basis with multiple packaging and module-level thermal issues when reducing the size of components for a lightning system in a car, while managing the routing of very high current. The study provides a better understanding of the strengths and weaknesses of the IC incorporation into a system module level, for both present and future product development. The reference design is evaluated at a system level, and several improvements are identified to enhance the overall thermal performance of the lightning system. The main concern is related to the possibility of exceeding the thermal budget for a large system incorporating several PQFN (Power Quad Flat No-Lead Package) packages with additional heat dissipation devices in an enclosure, at an external ambient temperature of 85°C. Due to the compactness of the device, there are only limited solutions to extract the heat from the high power dissipation system. The impact on the thermal balance of the trace dissipation, the location and size of the pins connecting the two boards (motherboard and daughter board) forming the system, the header heating and other passive components under various powered conditions are evaluated. A revised model includes additional pins (reduced diameter), modified motherboard and harness structures and their locations; the impact of additional heater traces on both top and bottom surfaces of the motherboard, and a modified daughter board design, is also evaluated. The resulting peak temperatures range from 118.3°C to 137.3°C and the corresponding junction-to-ambient thermal resistances (Rja) vary from 8.4°C/W to 8.8°C/W. Rja is defined as the temperature difference between the peak device and ambient divided by the total power dissipation of the PQFN packages. An optimized design is further evaluated, with lowered thermal resistance from the motherboard, the board-to-board pins, the junction box board, and the wiring harness. The thermal budget is satisfied, as the peak temperatures reached by the two designs are below the 150°C limit. Additional experimental results are used to benchmark the simulation results, within 1–6% accuracy.

Copyright © 2007 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In