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Trouble with wave solder pallet

SuePH

#32009

Trouble with wave solder pallet | 12 January, 2005

Help!! Just got some new wave solder pallets in house. The pallets are 12 by 8 inches solid composite, with only two 1/2 inch by 1 inch spots cut out for the connectors. When they go over the wave, the solder wants to cling to the bottom of the pallet instead of falling back into the solder pot which causes molten solder to cascade over the side of the pot onto the bed of the wave solder machine. The fixture house says they have never heard of this before. Has anyone had this happen and what did you do to solve it.

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Grant

#32013

Trouble with wave solder pallet | 12 January, 2005

Hi,

Are you coating the bottom of the palette with flux? What's the material of the palette. I have not seen that, but we did have some weird problems when we did not add flux on a virgin palette, but once it dirtied up a little it was ok.

We had a solder residue sticking to the palette, but that went away after about 2 passes through the machine. Nothing like you are mentioning though, and it sounds severe.

Regards,

Grant

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guest

#32014

Trouble with wave solder pallet | 12 January, 2005

Try scoring the underside of the pallet every inch or so, perpendicular to direction of travel

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RDR

#32016

Trouble with wave solder pallet | 12 January, 2005

Are you positive that the solder is sticking to the bottom of the fixture OR is it pushing the wave down so far that the solder is "squirting" out from underneath the pallet. This happens when deep/thick pallets are run at the same wave height as a non-fixtured PCBA.

I would make sure that the fixture is getting fluxed if sticking is really the problem.

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SuePH

#32019

Trouble with wave solder pallet | 12 January, 2005

Thanks for the replies. I use a foam fluxor, so the pallet is well fluxed. This is my first expierence with this thick of a pallet. Maybe Russ has a handle on it when he says that the wave height is just too high.

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RDR

#32021

Trouble with wave solder pallet | 12 January, 2005

I have seen the solder shoot out at least 4"-6" from both the leading and trailing edge when this happens. If the open pockets are real deep you may want to use a turbulent/chip wave for soldering, sometimes this leaves bridges however.

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#32023

Trouble with wave solder pallet | 12 January, 2005

Sue, What is the material your pallet is made of?? Are your thru pocket openings beveled??

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KEN

#32024

Trouble with wave solder pallet | 12 January, 2005

How thick is this pallet? 6mm, 8mm, 10mm?

I would look at:

Make sure you're pot height is correct (lead clearance). If you are burrying the pallet in the fountain, your going to "push" a large volume away. The solder "push" should not plow over the pallet leading edge (which equals the top of the PCB)

I bet your solder fountain is too tall. I have seen this exact same problem where the pump RPM was way too high (compensating for a piss-poor thermal profile). The excess volume of solder was deflected out the sides and actually fell outside the pot.

If it turns out to be a pallet issue, you might consider contacting

Pentagon EMS

These guys have an incredible wealth of knowledge about wave pallets and selective soldering.

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SuePH

#32038

Trouble with wave solder pallet | 13 January, 2005

The pallets are made of a black composite that is 5MM thick, and yes, the bottom is beveled to the cut out space for the connectors. The wave solder machine is a Treiber, so the wave height is hand set. I always aim for the center of the leading edge of the pallet, never had this problem before. But like I said earlier, I have not had the opportunity to use a pallet this thick before either.

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