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Is it good or is it bad?

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BKR

#55437

Is it good or is it bad? | 9 July, 2008

We are using a right-angle SMT power connector on a board. The connector has 4 leads and two board alignment pins. The layout for the board is such that 1 of the leads is not used and the pad for the lead is not connected to anything, not even ground. The situation we are seeing is that this one lead, for whatever reason, does not want to wet as well as the others. In many cases, it looks like the lead is floating on the solder under it when the other 3 leads solder fine. My question is this: Is touch-up of this lead to IPC standards required when the lead of the part is not connected to any circuit on the board?

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#55462

Is it good or is it bad? | 10 July, 2008

We wouldn't get our underware in a knot about poor wetting on a lead that is not connected to the board. IPC standards seen to say that the inspector should use common sense in interpreting standards requirements. Then again, it's not all that common, as they say.

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BKR

#55477

Is it good or is it bad? | 11 July, 2008

I agree that it should be a non-issue considering that the primary purpose of a solder joint is to electrically connect the lead to the board. However, there are some here that think these leads should be touched up because this part is a power jack and feel the added mechanical attachment would be beneficial. Little do they know that by reflowing the joint (lead free, I might add), they are further degrading the bond between the pad and the laminate so in the end, the added time spent "fixing" is doing nothing for the reliability of the assembly and adding cost at the same time.

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#55478

Is it good or is it bad? | 11 July, 2008

But why not find the cause so later when that lead is used you know how to fix it. Working hard at not working is what's wrong with the world today.

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