Failure Analysis for Gold Wire Bonding of Sensor Packaging Based on Experimental and Numerical Methods

Area of Science:

• Materials Science
• Mechanical Engineering
• Reliability Engineering

Background:

• Automotive sensors operate in demanding environments, increasing the risk of failure.
• Gold wire bonding is critical for sensor reliability, but susceptible to mechanical stress.
• Understanding failure modes is essential for improving sensor durability.

Purpose of the Study:

• To evaluate the reliability of gold wire bonding in automotive sensors.
• To investigate failure modes and mechanisms under mechanical stress.
• To develop a new failure criterion for bonding interfaces.

Main Methods:

• Finite-element analysis (FEA) was used to model wire pull and shear tests.
• Three-dimensional quantitative modeling simulated bonding delamination and stress concentration.
• Experimental verification validated the simulation results.

Main Results:

• FEA revealed stress concentration and delamination during bonding failure.
• The bonding-slip method (BSM) characterized gold ball detachment through three states: deformation accumulation, cracking, and disengagement.
• Failure shear force was determined to be 42 g for complete interface separation.

Conclusions:

• The proposed three-state model effectively illustrates interface stress evolution.
• The study provides a new theoretical framework for understanding bonding interface failure.
• This work contributes to establishing a novel failure criterion for automotive sensor reliability.