liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
On thermomechanical durability analysis combined with computational fluid dynamics thermal analysis
Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
Jönköping University Jönköping, Sweden, and SP Technical Research Institute of Sweden Borås, Sweden.
The Boeing Company Phantom Works Seattle, WA, USA.
The Boeing Company Commercial Airplanes Seattle, WA, USA.
Show others and affiliations
2007 (English)In: Proceedings of IMECE2007: ASME International Mechanical Engineering Congress and Exposition, American Society of Mechanical Engineers , 2007, 233-240 p.Conference paper (Refereed)
Abstract [en]

Results are presented on durability analysis of an electronic module subjected to thermal and power cycles, and vibration. A hierarchical analysis process for analyzing the durability of the module is described. The initial step is a transient thermal analysis of the unit in which the module is located. The three operating modes of the unit are modeled and analyzed using a commercially available computational fluid dynamics (CFD) tool. The tool generates a time history of the temperature at all points within the unit and module.

The second step comprises exporting temperatures from the transient temperature analysis to a durability prediction tool. The temperatures calculated by the global analysis are mapped to the printed wiring assembly (PWA) mounted within the box, yielding the temperature distribution of the PWA as functions of time. The durability tool utilizes a modified Coffin Manson formula together with the transient temperature profile to estimate the durability of each lead and solder joint included in the module. Thermomechanical fatigue level of leads and solder joints within the unit are reported as a cumulative damage index (CDI). The CDI is the ratio of the number of cycles required for the test item to endure under a life time to the number of cycles the item is predicted to sustain before failure.

Durability analysis of solder joint due to vibration is performed separately. The environment is specified according to the location where the unit is mounted. CDI due to vibration is added to form an overall CDI based on Miner’s rule.

Place, publisher, year, edition, pages
American Society of Mechanical Engineers , 2007. 233-240 p.
Keyword [en]
Durability analysis, thermal cycling, vibration, transient power dissipation
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
URN: urn:nbn:se:liu:diva-91897ISBN: 0791842991OAI: diva2:619542
ASME International Mechanical Engineering Congress and Exposition (IMECE 2007), November 11–15, 2007, Seattle, Washington, USA
Available from: 2013-05-04 Created: 2013-05-04 Last updated: 2013-12-03Bibliographically approved
In thesis
1. Thermal Fatigue Life Prediction of Solder Joints in Avionics by Surrogate Modeling: A Contribution to Physics of Failure in Reliability Prediction
Open this publication in new window or tab >>Thermal Fatigue Life Prediction of Solder Joints in Avionics by Surrogate Modeling: A Contribution to Physics of Failure in Reliability Prediction
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Manufacturers of aerospace, defense, and high performance (ADHP) equipment are currently facing multiple challenges related to the reliability of electronic systems. The continuing reduction in size of electronic components combined with increasing clock frequencies and greater functionality, results in increased power density. As an effect, controlling the temperature of electronic components is central in electronic product development in order to maintain and potentially improve the reliability of the equipment. Simultaneously, the transition to lead-free electronic equipment will most probably propagate also to the ADHP industry. Compared to well-proven tin-lead solder, the knowledge about field operation reliability of lead-free solders is still limited, as well as the availability of damage evaluation models validated for field temperature conditions. Hence, the need to fill in several knowledge gaps related to reliability and reliability prediction of lead-free solder alloys is emphasized. Having perceived increasing problems experienced in the reliability of fielded equipment, the ADHP industry has suggested inclusion of physics-of-failure (PoF) in reliability prediction of electronics as one potential measure to improve the reliability of the electronic systems.

This thesis aims to contribute to the development of reliable ADHP systems, with the main focus on electronic equipment for the aerospace industry. In order to accomplish this, the thesis provides design guidelines for power distribution on a double-sided printed circuit board assembly (PBA) as a measure to improve the thermal performance without increasing the weight of the system, and a novel, computationally efficient method for PoF-based evaluation of damage accumulation in solder joints in harsh, non-cyclic field operation temperature environments.

Thermal fatigue failure mechanisms and state‑of‑the‑art thermal design and design tools are presented, with focus on the requirements that may arise from avionic use, such as low weight, high reliability, and ability to sustain functional during high vibration levels and high g-forces. Paper I, II, and III describes an in-depth investigation that has been performed utilizing advanced thermal modeling of power distribution on a double-sided PBA as a measure to improve the thermal performance of electronic modules.

Paper IV contributes to increasing the accuracy of thermal fatigue life prediction in solder joints, by employing existing analytical models for predicting thermal fatigue life, but enhancing the prediction result by incorporating advanced thermal analysis in the procedure.

Papers V and VI suggest and elaborate on a computational method that utilizes surrogate stress and strain modeling of a solder joint, to quickly evaluate the damage accumulated in a critical solder joint from non-cyclic, non-simplified field operation temperature profiles, with accuracy comparable to finite element modeling. The method has been tested on a ball grid array package with SnAgCu solder joints. This package is included in an extensive set of accelerated tests that helps to qualify certain packages and solder alloys for avionic use. The tests include -20°C to +80°C and -55°C to +125°C thermal cycling of a statistically sound population of a number of selected packages, assembled with SnAgCu, Sn100C, and SnPbAg solder alloys. Statistical analysis of the results confirms that the SnAgCu-alloy may outperform SnPbAg solder at moderate thermal loads on the solder joints.

In Papers VII and VIII, the timeframe is extended to a future, in which validated life prediction models will be available, and the suggested method is expected to increase the accuracy of embedded prognostics of remaining useful thermal fatigue life of a critical solder joint.

The key contribution of the thesis is the added value of the proposed computational method utilized in the design phase for electronic equipment. Due to its ability for time-efficient operation on uncompressed temperature data, the method gives contribution to the accuracy, and thereby also to the credibility, of reliability prediction of electronic packages in the design phase. This especially relates to applications where thermal fatigue is a dominant contributor to the damage of solder joints.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2013. 64 p.
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1521
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
urn:nbn:se:liu:diva-91903 (URN)978-91-7519-618-3 (print) (ISBN)
Public defence
2013-06-11, K3, Kåkenhus, Campus Norrköping, Linköpings Universitet, Norrköping, 10:15 (English)
The Knowledge Foundation
Available from: 2013-05-08 Created: 2013-05-04 Last updated: 2013-05-08Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Johansson, Jonas
By organisation
Physics and ElectronicsThe Institute of Technology
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 52 hits
ReferencesLink to record
Permanent link

Direct link