shear test

**Shear test** is the **destructive test that applies lateral force to bonded features such as ball bonds to measure interfacial strength and adhesion quality** - it complements pull testing in bond integrity evaluation. **What Is Shear test?** - **Definition**: Mechanical shear force is applied near bond interface until separation occurs. - **Primary Target**: Often used to evaluate first-bond ball adhesion to die pads. - **Result Data**: Includes shear force magnitude and observed fracture interface characteristics. - **Inspection Link**: Failure morphology indicates metallurgical and process quality at the interface. **Why Shear test Matters** - **Interface Validation**: Directly measures adhesion quality at critical bond surfaces. - **Defect Detection**: Identifies contamination, weak IMC formation, or pad-metallurgy issues. - **Process Control**: Sensitive metric for bonding parameter drift and tool wear. - **Qualification Strength**: Combined with pull test for fuller mechanical reliability assessment. - **Yield Protection**: Early shear failures signal high-risk lots before final release. **How It Is Used in Practice** - **Test Standardization**: Control shear tool height, speed, and contact position precisely. - **Failure Mapping**: Classify fracture types to link results with specific process defects. - **Corrective Loop**: Use shear trends to adjust bonding recipes and cleaning procedures. Shear test is **a key adhesion-focused test in bond quality qualification** - shear testing provides critical visibility into first-bond interface robustness.