bond strength

**Bond strength** is the **mechanical robustness of wire-bond interfaces measured by their ability to withstand applied force without failure** - it is a primary quality metric for assembly integrity. **What Is Bond strength?** - **Definition**: Quantitative measure of interconnect mechanical integrity at first and second bond locations. - **Evaluation Methods**: Typically assessed using pull and shear testing with failure-mode classification. - **Influencing Factors**: Bond energy, metallurgy, contamination, and tool condition. - **Acceptance Basis**: Compared against specification limits and qualified process windows. **Why Bond strength Matters** - **Yield Assurance**: Weak bonds correlate strongly with assembly failures and latent escapes. - **Reliability Confidence**: Adequate strength is needed to survive thermal, vibration, and aging stress. - **Process Monitoring**: Strength trends reveal drift in equipment or material quality. - **Customer Compliance**: Bond-strength metrics are common release criteria in qualification plans. - **Failure Prevention**: Early detection of weakened bonds reduces field-return risk. **How It Is Used in Practice** - **Sampling Plan**: Run strength tests by lot, wire type, and package zone. - **Mode Analysis**: Track not only force values but also where and how failure occurs. - **Corrective Action**: Adjust bonding parameters and tool maintenance when trends degrade. Bond strength is **a core mechanical KPI in wire-bond process control** - consistent strength margins are essential for robust package reliability.