Automotive electronics design and manufacture present unique challenges for product reliability. Recent trends toward mounting electronic systems directly onto engines introduce a new level of severity in terms of thermal and vibration environments. Automotive microelectronic packages experience thermal stresses that can possibly cause components and electrical interconnection damage. The loss of electrical interconnection due to coarse Aluminium wires in electronic modules is one of the most critical reliability problems in automotive electronics packaging. The paper intends to help understand and investigate the reliability of Aluminium wire bonds that make the electrical connection between integrated chips and the leads inside a typical leaded electronic package like TO247. Finite element modeling (FEM) is used to simulate the stresses the package goes through during reliability tests. Results are compared to empirical testing. The FE model consists of the entire TO247 package including the leadframe, overmold, chip, substrate, Al wire loops and corresponding bond pads. Results from simulations provide information to map out high stress locations on the heels of the wirebonds due to package warp. In addition, the results also provide manufacturing engineers the insight to develop general bonding guidelines for Aluminium wires. As a result of this exercise, the development team is able to counter the issue and provide a design guideline to design the leadframe, place components away from high stress locations and pursue a more symmetrical layout to reduce the effect of thermal stresses.

Volume Subject Area:
Electronic and Photonic Packaging
Topics:
Finite element analysis, Reliability, Wire, Aluminum, Design, Stress, Finite element model, Thermal stresses, Bonding, Damage, Electronic packages, Electronic packaging, Electronic systems, Electronics, Engineering simulation, Engineers, Engines, Manufacturing, Modeling, Product reliability, Simulation, Symmetry (Physics), Teams, Testing, Vibration, Warping
1.
F. Thome and D. B. King, “Applications, Needs, and Alternatives,” High Temperature Electronics, R. Kirschman, Editor, IEEE Press, New Jersey, 1999, pp. 106.
2.
Cuong Van Pham, PhD., “A New Approach to Robust Wire bonding.”
3.
Richard J. Harries, Suresh K. Sitaraman, “Numerical Modeling of Interfacial Delamination Propagation in a Novel Peripheral Array Package,” IEEE Transaction on Components and Packaging Technologies, Vol. 24, No. 2, June 2001
4.
Yasuo Takahashi, Michinobu Inoue, “Numerical Study of Wire Bonding–Analysis of Interfacial Deformation between Wire and Pad,” Journal of Electronic Packaging, Vol. 124/27, March 2002.
5.
Cuong Van Pham, PhD, “Let revise the ASTM Method F.459 for Wirebonding process control.”
6.
“Nordic Electronics Packaging Guideline”
7.
Sihua Wen, M. Sc. Thesis, Virginia Polytechnic Institute and State University, “Thermal and Thermo-Mechanical Analyses of Wire Bond vs. Three-dimensionally Packaged Power Electronics Modules,” December 16, 1999.
8.
Ciappa
 
Mauro
, “
Selected failure mechanisms of modern power modules
,”
Microelectronics Reliability
,
42
(
2002
)
653
–
667
.
This content is only available via PDF.
Copyright © 2005
 by ASME
You do not currently have access to this content.