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Solder balls

AF Ng

#6825

Solder balls | 11 June, 2001

Can someone helps to interpret the IPC-A-610's requirement on solder balls ( less than 5 mils in diameters.). We found about 6 to 10 balls ( less than 5 mils ) scattered in a 600 sq mm board. Is it consider failing for class 2 product ?.

Thank you. AF

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#6830

Solder balls | 11 June, 2001

IPC-A-610 uses words to the effect that it�s a Class 2 process indicator, if either: * Entrapped or encapsulated solder balls that are within 0.13 mm [0.00512 in] of lands or connectors, OR * Entrapped or encapsulated solder balls exceed 0.13mm [0.00512 in] in diameter. OR * More than five solder balls / splashes 0.13 mm [0.00512 in] or less per 600 mm2 [0.3 in2].

IPC-A-610 uses words to the effect that it�s a Class 2 defect if either: * Solder balls / splashes violate minimum electrical clearance [within 0.13 mm [0.00512 in] of lands or connectors]. OR * Solder balls / splashes are not entrapped or encapsulated. OR * Solder balls / splashes not attached to metal surface.

So you probably need to be more specific about the balls that are considering.

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AF Ng

#6836

Solder balls | 12 June, 2001

Thank you, Mr Dave. Specifically, there are tiny balls spreading on the boards ( on top of solder resists, and not encapsulated). They are not near to any land/pad or connector. I do not think they post any electrical problem. They are quite far away from components and IC leads. And these tiny balls are less than 5 mil in diameter. I just would like to find out that does it fail the IPC standards, as the wording used in IPC is quite vague.

Thank you AF

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#6840

Solder balls | 12 June, 2001

I'd say that this is close enough to call a meeting of your Material Review Board and hash this out.

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htwyman

#6841

Solder balls/paste | 12 June, 2001

One of my FAQ pages relates to solder balls - check it out at:

http://www.Twyman.org.uk/FAQ/Solder-Paste.htm

Harvey Twyman http://www.Twyman.org.uk/CV

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