Defect Description
Component leads that are bent, twisted or of other out-of-shape situations that result in mechanically weak contacts interconnects between the defective leads and the board.
Defect Formation Process(s)
One possible cause of distorted leads is the mechanical stresses during handling, pick and place and board mounting processes.
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List of Tests to Precipitate this Defect |
Failure Acceleration |
Likihood to Precipitate Defect (condition) |
Failure Mechanism(s) |
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Thermal Cycling |
• Cyclic thermal mechanical stress accelerates fatigue of weak contacts • Thermal mechanical stress can cause fracture of weak contacts |
✔ |
Thermal mechanical fatigue Thermal mechanical overstress |
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Random Vibration (RS/ED) |
• Random Vibration accelerates fatigue of weak contacts • Random Vibration can cause fracture of weak contacts |
✔/✇ |
Mechanical fatigue Mechanical |
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Combined Environment |
• Combination of Thermal Shock and Random Vibration |
✔ |
Combination of Thermal Shock and Random Vibration |
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Bend Test |
• Bending can cause fracutre of weak contacts |
✇ |
Mechanical overstress |
References
Permission for pictures
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