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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Ron Costa

#14719

Solder Balls | 12 August, 1998

Hello everyone, I am currently running a gold plated SMT board and am experiencing tiny solder balls between the pads and the masking between the 20 mil pitch devices. I'm looking at these boards with a 60x microscope. IPC-610 say's any visible solder balls are not acceptable. The balls do not come off in wash. The profile is good. Are tiny solder balls a problem as far as reliability? Should they be removed? I also see grainy solder joints on the gold leaded devices. Does anyone have any information on this? Thanks for the inputs...........Ron

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Ben Salisbury

#14720

Re: Solder Balls | 21 August, 1998

| Hello everyone, | I am currently running a gold plated SMT board and am experiencing tiny solder balls between the pads and the masking between the 20 mil pitch devices. I'm looking at these boards with a 60x microscope. IPC-610 say's any visible solder balls are not acceptable. The balls do not come off in wash. The profile is good. | Are tiny solder balls a problem as far as reliability? | Should they be removed? | I also see grainy solder joints on the gold leaded devices. Does anyone have any information on this? | Thanks for the inputs...........Ron Ron- According to IPC-A-610 Rev B section 4.1 NonConforming Process indicator-Class 1,2,3 Solder Balls/Splashes which are within .13mm of lands or traces, or exceed .13mm in diameter. More than five(5) solder balls/splashes (.13mm or less) per 600 mm Squared. If they meet this criteria they must be removed. We ran into the exact same problem a while back and it turned out to be operator error...the underside on the stencil was not being cleaned off properly. -Ben

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