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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


2%Ag?

Jenna Sweterlitsch

#13020

2%Ag? | 11 January, 1999

This question is directed to anyone having eperience with Sn62Pb36Ag2 solder balls for BGA's. Have you seen anything like a rough, raisin-like surface texture after ball attach? If so, what did you do about it?

Thanks!

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Dean

#13021

Re: 2%Ag? | 11 January, 1999

| This question is directed to anyone having eperience with Sn62Pb36Ag2 solder balls for BGA's. | Have you seen anything like a rough, raisin-like surface texture after ball attach? If so, what did you do about it? | | Thanks! | I have seen this before, though it was not 2% silver. Verify your thermal profile...remember this trinary alloy turns liquodus above 230 deg. C. Also, vibration can cause surface texture to form if excessive vibration is present at the point of solifification (cooling down). Sort of like the mineral rings that form when a mud puddle evaporates.

Let us know what you find. Dean.

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Dave F

#13022

Re: 2%Ag? | 13 January, 1999

| This question is directed to anyone having eperience with Sn62Pb36Ag2 solder balls for BGA's. | Have you seen anything like a rough, raisin-like surface texture after ball attach? If so, what did you do about it? | | Thanks! | Jenna: We've used buckets of Sn62Pb36Ag2. It's not the solder type. Bad batch, bad components, bad process, or all of the above. TTYL Dave F

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