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SMT electronics assembly manufacturing forum.


Solder Paste

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#54118

Solder Paste | 20 March, 2008

We have a class 3 SMT build that requires the paste conforms to J-STD-005 RE LO. We have not used a low activity flux in the past and would prefer not to have to change our wash process or change to no-clean paste for these builds. I have researched a few options but they are brands I am not familiar with and this type of product seems hard to come by unless I'm missing something. Has anyone used a low activity flux paste in which the flux can easily be removed with plain DI water wash? What is it and was it good stuff?

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#54119

Solder Paste | 20 March, 2008

Why are you planning to clean low residue flux? There are cleanable low residue fluxes, but why would you wan to clean it?

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#54120

Solder Paste | 20 March, 2008

In addition to Dave�s comments

RE: Stands for RESIN (purified or modified rosin) No resin can be cleaned with pure DI water (requires saponification).

L0: Stand for halide free activation which can safely be left on the boards. To my knowledge all activators that qualify for L0 are not soluble in pure DI water.

All flux types ending in L0 according J-STD-004 are no-clean/ low residue and are not formulated for cleaning.

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#54122

Solder Paste | 20 March, 2008

Our customer is putting our process under a microscope and is requiring that we wash all product. They want no flux residues left on the solder joints. We do not want to add anything to our DI only wash system so we're trying to find a way around it.

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#54124

Solder Paste | 20 March, 2008

You need to use speial cleaning solution to clean the residues from no clean pastes. Alpha has a solution,(I think Alpha 2010)that can clean no-clean residues. Zestron is another company which specializes in cleaning no clean residues.

contact Alpha and Zestron

www.zestron.com

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#54176

Solder Paste | 26 March, 2008

well i do not know if u fixed this problem already. But i cand share form my experience some info with u. We used a vigon A200 solution for such an application. the cleaner is good. But...it gives u troubles depending on the quantity of flux. It can remains there...this solution are usually silicon based. I think silicon is sticking there and leaves white traces on board. SO, depending on ur process even u can try this one...or the agressive one..S200 or something like this. Take care with the cleanliness of the machine....if the PH of the solution is sliglhy changed,,,the cleaning solution..is precipitating on ur boards...so...good luck :) nico

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#54187

Solder Paste | 26 March, 2008

Thanks for the replies. Our customer has shifted toward allowing us to prove that our current cleaning process can provide a product that meets their cleanliness requirements using our current paste/wire/flux products. (This is just a pilot build for the possibility of production runs). We do not want to add detergents or saponifiers to our in-line wash. Due to tight time contraints, we do not have time to add a new wash system.

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#54190

Solder Paste | 26 March, 2008

Isn't this great? After all those bad things people said about customers in a recent thread. Good thing they weren't listening, eh?

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#54203

Solder Paste | 27 March, 2008

AMTech makes REL0 (4300 series) pastes that are water washable. You might want to try a sample...

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