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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Ryan Jennens

#15949

Pallet problems | 8 May, 1998

I am running boards with gold fingers on a pallet for masking purposes. The pallets worked fine for a while but know the gold fingers are getting solder on them. We have tried everythin: new pallets, cleaning the pallet and board to be sure there were no solder balls or paste involved, changing the pallet material to the high temp stuff, etc. The pallet manufacturer has always given us high quality stuff and I think the pallet is in good shape. There is no visible gap between the pallet and board. We are currently taping, which we all know is very labor intensive. How are the gold fingers being soldered?

reply »

Chrys

#15950

Re: Pallet problems | 8 May, 1998

| I am running boards with gold fingers on a pallet for | masking purposes. The pallets worked fine for a while | but know the gold fingers are getting solder on them. We | have tried everythin: new pallets, cleaning the pallet | and board to be sure there were no solder balls or paste | involved, changing the pallet material to the high temp | stuff, etc. The pallet manufacturer has always given | us high quality stuff and I think the pallet is in good | shape. There is no visible gap between the pallet and | board. We are currently taping, which we all know is very labor | intensive. How are the gold fingers being soldered? This happened to us. Our spray fluxer was not set properly and was dousing the board with flux. Even though there was no noticable gap between the pallet and the gold fingers, there was enough for flux to run in. And, when there's heat and flux, solder will follow. Also, don't forget that even the high temp pallet material will warp a little when its hot, so just because there's no gap when it's cool, doesn't mean there's no gap when it hits the wave. Chrys

reply »

Aric Parr

#15951

Re: Pallet problems | 19 May, 1998

| | I am running boards with gold fingers on a pallet for | | masking purposes. The pallets worked fine for a while | | but know the gold fingers are getting solder on them. We | | have tried everythin: new pallets, cleaning the pallet | | and board to be sure there were no solder balls or paste | | involved, changing the pallet material to the high temp | | stuff, etc. The pallet manufacturer has always given | | us high quality stuff and I think the pallet is in good | | shape. There is no visible gap between the pallet and | | board. We are currently taping, which we all know is very labor | | intensive. How are the gold fingers being soldered?

| This happened to us. Our spray fluxer was not set properly and was dousing the board with flux. Even though there was no noticable gap between the pallet and the gold fingers, there was enough for flux to run in. And, when there's heat and flux, solder will follow. Also, don't forget that even the high temp pallet material will warp a little when its hot, so just because there's no gap when it's cool, doesn't mean there's no gap when it hits the wave. | | Chrys I remember a similar problem from a few years ago at a previous employer this happened with shadow pallets. The problem appeared overnight and no amount of process changes could stop the leaking. We releveled the wave from ground up and the problem was fixed. We found that the lock nuts that held pots, conveyors, rails, wave generators...all had worked loose. The problem dissappeared immediately, never to return.

reply »

Essemtec Spider SMT Fluid Dispenser

PCB X-Ray Inspection