Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


SMT SOLDERING

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CHITRA

#45031

SMT SOLDERING | 14 November, 2006

When we reflow solder SMT PCB with SMT Electrolytic capacitor- 5MM sized ,the capacitor gets burst and all other adjacent and surrounding components also get disturbed. What could be reason for this. What should be done to avoid this problem.

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aj

#45036

SMT SOLDERING | 14 November, 2006

I take it you mean that the Cap "explodes"! If so it sounds like the cap is not rated for the Temperature profile you are using.

Check the temp.spec of the part. Check your reflow profile.

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Rob

#45037

SMT SOLDERING | 14 November, 2006

Degassing - the air in the void above the electrolyte expands, or in some cases the electrolyte vapourises, blowing the top of the cap from the base.

Sometimes electrolyte can also leak out around the base seal. This is also a failure as the cap won't last that long without this.

As AJ mentioned these may not be rated for Lead Free temperatures, or they may have been store for a long period, absorbing moisture through the bung.

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SMT in-printer dispensing

reflow oven profiler