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Reply To: | TechNet E-Mail Forum. |
Date: | Thu, 11 Nov 1999 18:23:23 -0500 |
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aged solder paste sometimes have void problems...usually, under high RH% MFG
condition...If you are "lucky", you would see solder splash coupled with
voids (solder balls, etc), otherwise, it is not so easy to spot the problem
...(it was a hard lesson to learn many years ago).
where are you located? warm and high RH?
jk
At 10:45 AM 11/11/99 -0500, you wrote:
> Hi gang,
> We are cross-sectiong some solder joints, and are seeing some
> voiding inside the joint itself, that appears to be "air pockets" that
> were inside the joint when reflowed. There is no visible indication
> externally of any voiding, but it is fairly prevalent inside various
> component solder joints when cross-sectioned.
>
> I cannot find criteria or mention of this in the specifications I
> have. ANSI/IPC-A-610A shows voiding criteria for thru-hole components,
> but none for SMD.
>
> Does anyone have knowledge they can share on this topic? Is there a
> spec on internal SMD joint voiding available? Do you guys and gals see
> this occasionally in your joints?
>
> Please, enlighten me with your collective wisdoms!
> TIA!
>
> Jeff Hempton
> United Technologies Electronic Controls
>
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