Same pattern of capacitor crack

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Hi All, We encounter capacitor crack in the ICT, it contr... - Nov 13, 2008 by raiders

We have seen a similar problem. Turned out to be mechanical ... - Nov 13, 2008 by Pete B

Yes, it does look like a typical crack due to mechanical ove... - Nov 13, 2008 by Vlad

raiders

#57266

Same pattern of capacitor crack | 13 November, 2008

Hi All,

We encounter capacitor crack in the ICT, it contributes 2% of the failure. We are not sure whether these crack coming from the SMT. All these crack having the same pattern. Please refer to attached file. Anybody encounter the same thing before?

Attachments:

crack.doc

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Pete B

#57270

Same pattern of capacitor crack | 13 November, 2008

We have seen a similar problem. Turned out to be mechanical stress on the component caused by the method of location and clamping at ICT. Where is the component located on the assembly? Poorly adjusted clamping pillars on clamshell fixtures can cause bending moments on the PCB being tested that can lead to stress fractures.

Another potential cause that we have seen is when breaking out PCB from panelisation using either hooked blade 'shear' or pizza cutter type separation systems. If the component is located near to the edge it could be subject to physical impact resulting in mechanical damage. Also components perpendicular to the edge in these scenarios are more susceptible than those parallel to it.

Hope this is helpful.

Pete B.

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Vlad

#57272

Same pattern of capacitor crack | 13 November, 2008

Yes, it does look like a typical crack due to mechanical overloading (bending) of teh component. Usually because of the board flexing

Vlad

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