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no clean rework

Gian.D

#10229

no clean rework | 9 August, 1999

hello to everybody, we have a really satisfactory no clean process, both smt/reflow and wave soldering, but we get troubles with defects rework; does anybody know how to eliminate flux residues or how not to produce them during rework operations? Thanks to everyone. g.d.

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Dreamsniper

#10230

Re: no clean rework | 10 August, 1999

| hello to everybody, | we have a really satisfactory no clean process, both smt/reflow and wave soldering, but we get troubles with defects rework; | does anybody know how to eliminate flux residues or how not to produce them during rework operations? | Thanks to everyone. | g.d. | do you mean that u r having residues from your no clean process? and that during rework u produce residues? try changing to other flux, solder or solder paste supplier. during rework u need to use no clean stuffs too... if this is already what u r doing try above step. hope it might help.

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Gian.D

#10231

Re: no clean rework | 10 August, 1999

| | hello to everybody, | | we have a really satisfactory no clean process, both smt/reflow and wave soldering, but we get troubles with defects rework; | | does anybody know how to eliminate flux residues or how not to produce them during rework operations? | | Thanks to everyone. | | g.d. | | | do you mean that u r having residues from your no clean process? | and that during rework u produce residues? | try changing to other flux, solder or solder paste supplier. | during rework u need to use no clean stuffs too... if this is already what u r doing try above step. | hope it might help. |

yes and thanks dreamsniper, the problem is, above all, using rework materials (fluxes) because ,i think, yhat it is difficult to reach right decomposition temperatures such to eliminate white residues. Obviously we don,t like using solvent for cleaning... ok? thanks again. g.d.

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Brian

#10232

Re: no clean rework | 10 August, 1999

| | | hello to everybody, | | | we have a really satisfactory no clean process, both smt/reflow and wave soldering, but we get troubles with defects rework; | | | does anybody know how to eliminate flux residues or how not to produce them during rework operations? | | | Thanks to everyone. | | | g.d. | | | | | do you mean that u r having residues from your no clean process? | | and that during rework u produce residues? | | try changing to other flux, solder or solder paste supplier. | | during rework u need to use no clean stuffs too... if this is already what u r doing try above step. | | hope it might help. | | | | yes and thanks dreamsniper, | the problem is, above all, using rework materials (fluxes) because ,i think, yhat it is difficult to reach right decomposition temperatures such to eliminate white residues. | Obviously we don,t like using solvent for cleaning... ok? | thanks again. | g.d. | | Gian

You alarm me when you talk of white residues in a "no-clean" process. This should not happen. It sounds like you have compatibility problems between different residues and/or a poorly polymerised solder mask.

There exists on the market flux-cored wire specifically for what you are doing. Much of the 1.5% flux is sublimated, and the rest leaves a thin, clear, transparent, not-too-glossy residue which is almost invisible. As far as I know, it is compatible with many other products. The only caveat is that the operator must know how to use it, for best results.

Ciao

Brian

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#10233

Re: no clean rework | 10 August, 1999

Hello,

Could be that touchup operators are using too much flux. What are you dispensing flux with. Disposable or refillable flux pens are good to have around.

| | | |

hello to everybody, | | | | we have a really satisfactory no clean process, both smt/reflow and wave soldering, but we get troubles with defects rework; | | | | does anybody know how to eliminate flux residues or how not to produce them during rework operations? | | | | Thanks to everyone. | | | | g.d. | | | | | | | do you mean that u r having residues from your no clean process? | | | and that during rework u produce residues? | | | try changing to other flux, solder or solder paste supplier. | | | during rework u need to use no clean stuffs too... if this is already what u r doing try above step. | | | hope it might help. | | | | | | | yes and thanks dreamsniper, | | the problem is, above all, using rework materials (fluxes) because ,i think, yhat it is difficult to reach right decomposition temperatures such to eliminate white residues. | | Obviously we don,t like using solvent for cleaning... ok? | | thanks again. | | g.d. | | | | | Gian | | You alarm me when you talk of white residues in a "no-clean" process. This should not happen. It sounds like you have compatibility problems between different residues and/or a poorly polymerised solder mask. | | There exists on the market flux-cored wire specifically for what you are doing. Much of the 1.5% flux is sublimated, and the rest leaves a thin, clear, transparent, not-too-glossy residue which is almost invisible. As far as I know, it is compatible with many other products. The only caveat is that the operator must know how to use it, for best results. | | Ciao | | Brian |

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Gian.D

#10234

Re: no clean rework | 12 August, 1999

| Hello, | | Could be that touchup operators are using too much flux. What are you dispensing flux with. Disposable or refillable flux pens are good to have around. | |Good! could you suggest some suppliers name or address or web site or e.mail....ecc.? it could be part of the problem solution ; many thanks ...if you can. G.D. | | | | | | | | | | | | | hello to everybody, | | | | | we have a really satisfactory no clean process, both smt/reflow and wave soldering, but we get troubles with defects rework; | | | | | does anybody know how to eliminate flux residues or how not to produce them during rework operations? | | | | | Thanks to everyone. | | | | | g.d. | | | | | | | | | do you mean that u r having residues from your no clean process? | | | | and that during rework u produce residues? | | | | try changing to other flux, solder or solder paste supplier. | | | | during rework u need to use no clean stuffs too... if this is already what u r doing try above step. | | | | hope it might help. | | | | | | | | | | yes and thanks dreamsniper, | | | the problem is, above all, using rework materials (fluxes) because ,i think, yhat it is difficult to reach right decomposition temperatures such to eliminate white residues. | | | Obviously we don,t like using solvent for cleaning... ok? | | | thanks again. | | | g.d. | | | | | | | | Gian | | | | You alarm me when you talk of white residues in a "no-clean" process. This should not happen. It sounds like you have compatibility problems between different residues and/or a poorly polymerised solder mask. | | | | There exists on the market flux-cored wire specifically for what you are doing. Much of the 1.5% flux is sublimated, and the rest leaves a thin, clear, transparent, not-too-glossy residue which is almost invisible. As far as I know, it is compatible with many other products. The only caveat is that the operator must know how to use it, for best results. | | | | Ciao | | | | Brian | | | |

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DENNIS FOWLER

#10235

Re: no clean rework | 18 August, 1999

| | | Gian | | | | | | You alarm me when you talk of white residues in a "no-clean" process. This should not happen. It sounds like you have compatibility problems between different residues and/or a poorly polymerised solder mask. | | | | | | There exists on the market flux-cored wire specifically for what you are doing. Much of the 1.5% flux is sublimated, and the rest leaves a thin, clear, transparent, not-too-glossy residue which is almost invisible. As far as I know, it is compatible with many other products. The only caveat is that the operator must know how to use it, for best results. | | | | | | Ciao | | | | | | Brian | | |

Dennis

The white residue you spoke about is a chemical reaction between the no-clean flux and alcohol. If your operators indicate they used nothing to clean the area, look at the top of their alcohol bottles you will see the same residue..

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