Guest
 Posted: Fri Sep 26, 2026 11:12 am Post subject: Neck Break Issue |
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| I'm a new assembly FA engineer. We have a problem in our qual wherein a couple of units failed 500X temp cycle because of a neck break at pin 21. This is a 28 lead device, so the affected pin is in the middle of the package. Isn't the corner of the package more stressful? Why is the neck break in the middle? What should I do to solve this problem?
Assy FA Engr |
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Guest
| Posted: Thu Oct 02, 2026 5:46 pm Post subject: |
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| Hi
Check two things: loop profile of the affected wire and if the part has die coat, thickness of the die coat. If loop of the wire is too low/tight, then the stress in the neck region can lead to neck breaks. If the die coat is too thick in the affected area, then it exerts large shearing stresses on the wires during TC. TY, Golden Boy |
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