Solder Balls on end of long pins

I am wave soldering a single sided through hole PCB array with (6) .040" round diameter pins that sit .5" off the PCB, and .080" apart. The problem being experienced is that solderballs are appearing on the end of the pins. I have tried decreasing the conveyor speed along with changes to the lamda wave with no significant results. Currently in order to eliminate the solder balls I have to raise the conveyor running the arrays through a second time allowing just the bottom of the pins to touch the wave, thus eliminating the solder balls. Anyone have any suggestions as to solder long pins without solder balls on only one pass through the wave?

Regards,

Rob

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| I am wave soldering a single sided through hole PCB array with (6) .040" round diameter pins that sit .5" off the PCB, and .080" apart. The problem being experienced is that solderballs are appearing on the end of the pins. I have tried decreasing the conveyor speed along with changes to the lamda wave with no significant results. Currently in order to eliminate the solder balls I have to raise the conveyor running the arrays through a second time allowing just the bottom of the pins to touch the wave, thus eliminating the solder balls. Anyone have any suggestions as to solder long pins without solder balls on only one pass through the wave? | | Regards, | | Rob | I know it's not in the cards/wallet, but if it was a double sided, plated through hole board, better thermal transfer would be effected. This would eliminate the condition you describe.

Earl Moon

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| I am wave soldering a single sided through hole PCB array with (6) .040" round diameter pins that sit .5" off the PCB, and .080" apart. The problem being experienced is that solderballs are appearing on the end of the pins. I have tried decreasing the conveyor speed along with changes to the lamda wave with no significant results. Currently in order to eliminate the solder balls I have to raise the conveyor running the arrays through a second time allowing just the bottom of the pins to touch the wave, thus eliminating the solder balls. Anyone have any suggestions as to solder long pins without solder balls on only one pass through the wave? | | Regards, | | Rob | Rob - let me clarify my vision of what you are describing. you are running 0.5" pins through a wave and winding up with a drop like formation of excess solder at the bottom of the pin rather than what would normally be called a solder ball? then you are simply remelting the tips to remove the excess formation. if so, I would call it another case of gravity sucks. I would guess that the solder coating the pin is running down the length of the pin while still liquid, forming a drop at the bottom with surface tension, and then solidifying. what to do... put the pins in as a second op, mask most of the pin before soldering, use some sort of hot air knife to blow the drops off before they solify? any other ideas gang? good luck John Thorup

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