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Solder balls - Pb wave soldering

Rafal M.

#29833

Solder balls - Pb wave soldering | 4 August, 2004

Hello! My problem are solder balls in normal (with Pb) wave soldering proces. Balls appears between connector pads. I tried to change fluxes and preheating in machine (and combinations of both). What else can I do? I have no wide experience in soldering process.

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#29837

Solder balls - Pb wave soldering | 4 August, 2004

Are these solder balls on the wave side or the non-wave side?

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Rafal M.

#29851

Solder balls - Pb wave soldering | 5 August, 2004

Balls are on the wave side.

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Bryan

#29854

Solder balls - Pb wave soldering | 5 August, 2004

In my normal Pb process,we 've a station names "Remove the solder balls and clean the board",I think we'll also have such a station in our Pb-free process. Bryan

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#29876

Solder balls - Pb wave soldering | 5 August, 2004

For the �The Chip Wave Dilemma", look here: http://www.alphametals.com/products/fluxes/PDF/dilemma1.pdf

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#29877

Solder balls - Pb wave soldering | 5 August, 2004

If you like to absorb the cost of removing solder balls with SnPb, you will like it an even greater amount with Pb-free

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RDR

#29895

Solder balls - Pb wave soldering | 5 August, 2004

what type of flux are you using and what type of solder resist is on the PCB solder resist (Gloss or Matte), also what is the orientation of the connector to the wave flow and what is the pitch of the leads?

Russ

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#29992

Solder balls - Pb wave soldering | 11 August, 2004

Check cure of solder resist. Use a No clean low solids rosin flux this will stop problem. Should see almost zero solder balls if put through a single wave compared to a dual wave. If this is true then it is a resist issue and cannot 'resist' the solder for two heat cycles.

Either undercured or insufficient catalyst or hardener when first applied. Very common, but correct it does get a hell of alot worse with lead free. Its going to be fun cheers Greg BLT Circuit Services Ltd

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Loz

#29993

Solder balls - Pb wave soldering | 11 August, 2004

Last time I experienced this, one of the operators had increased the wave height. Reverted it back to the original setting and no more balls.

Under cured solder resist again? Mr Greg? Not doubting your summation but PWB vendors are too blame again?

I'd hoped that a similar thread could have provoked a reaction form the PWB vendors.

Anyone in that field care to comment?

Loz

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Rafal M.

#30002

Solder balls - Pb wave soldering | 12 August, 2004

We used fluxes: Cobar 94-QMB (no bismuth), RF800, Cobar94RXZ-M, with foam and spray fluxers: MBO clean alloy SN63PB37.experienced with changing preheatting, speed of covoyer single and double wave., we tried every combination. I think the problem is PCB - it's to adhesive when it's in soldering machine.

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#30005

Solder balls - Pb wave soldering | 12 August, 2004

Yes unfortunately solder resist again, getting boring I know. That green stuff on the boards causes all kinds of problems if not applied correctly. Can't blame the flux (as usual) or the process as he has tried all varients to no avail and therosin should have been an immediate fix. Resist has been a problem for years and believe me will be a problem for years to come, unless the PWB industry and resist suppliers get together. For instance we analysed one customers boards from eight different PWB vendors and got solder mask/plasticizers off the boards in the range of 0.6797 - 5.8210, the pass rate is 0.2-0.3 guess what these were all the same boards as well, so it is a fairly large problem. All the best Greg York Technical Sales Manager BLT Circuit Services Ltd

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roel

#30034

Solder balls - Pb wave soldering | 16 August, 2004

Concerning the solder-balls, there are a few causes for this. Try to slow down your solder-speed (P.e 80cm/min). Can you measure temperature after the pre-heat zone? Are there also blow-holes in the joints? Personally I think there is some water in the pcb's. You can also try to warm them in an external oven. (Your wave and fluxer are clean and straight?) Try these things as a beginning. Good Luck Roel

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Shean Dalton

#30058

Solder balls - Pb wave soldering | 16 August, 2004

Try to observe the board as it exits the wave, look for solder snapping as the leads finally exit the solder. The surface tension could be such that a "string" of solder stretches away from the wave until it finally breaks. Then, as the string recoils to the board it splatters creating solder balls. If you observe this action, try adjusting the amount of flux applied, or, try introducing quality nitrogen to your wave's exit side.

Shean Dalton Austin American Technology www.aat-corp.com

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