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Tin Whisker Formation?

Views: 1295

H

#41798

Tin Whisker Formation? | 25 May, 2006

Anyone think that this, http://img336.imageshack.us/my.php?image=nodule27wc.jpg, is a nodule which will eventually grow into a tin whisker?

Observe the plating on the component lead. Thanks in advanced for opinions.

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#41799

Tin Whisker Formation? | 25 May, 2006

hi, can't really see your picture, please rewiev the link regards Dominik

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Chunks

#41800

Tin Whisker Formation? | 25 May, 2006

REMOVE THE COMMA AT THE END OF THE LINK! H made a boo boo. Tin Whisker "Nodule"?

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#41801

Tin Whisker Formation? | 25 May, 2006

H, I tried without the commaat the end

http://img336.imageshack.us/my.php?image=nodule27wc.jpg

Seems to work. IMO, it looks like questionable component plating and not this so-called "nodule".

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Chunks

#41803

Tin Whisker Formation? | 25 May, 2006

Given the magnification used on this picture, this does not look like a nodule I've ever seen.

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#41806

Tin Whisker Formation? | 25 May, 2006

This sure doesn't look very healthy. The important things to know are A) You see this already right after reflow B) Is this showing up after the board has been in use for a while If you could answer these questions we could take it a step further.

Patrick

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H

#41847

Tin Whisker Formation? | 26 May, 2006

Patrick:

The image that you see was from a unit that was known to have gone through a 5-year environmental life test.

However, we took another board, pre-refow, and scoped a similar device. It exhibited the same grainy component plating.

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#41850

Tin Whisker Formation? | 26 May, 2006

Its it possible to post a picture from right after reflow? To see what we start with and compare the difference after 5 years.

The grainy structure is not as much a concern as the growth-like appearance on the boundary of the solder.

What paste alloy are you using? What is the plating alloy?

A spectrum analyses would also be helpful, if that growth is a "pure tin crystal" it could indicate a potential start of whiskering.

Thanks a lot for sharing that with us.

Patrick

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