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Selective Soldering Issues

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#66640

Selective Soldering Issues | 21 June, 2012

We are currently using an ACE K.I.S.S. 104. We used SN100 solder with AIM NC265 flux (no clean, alcohol-based). Also, we use topside preheat at 100 degrees C and a 6mm nozzle (as big as we can go with this application). The PCB has a matte finish as well.

We tend to get inconsistent solder issues: webbing, balls, bridging, etc. We have tried about every trick that we know and have even had a technician come out. Nothing helps. We've sent boards to ACE to see if they could help. Nope. Does anyone have any tips or tricks they have used in their selective soldering process or ideas of something we should try.

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#66641

Selective Soldering Issues | 21 June, 2012

Check your nitrogen. It sound like you do not have any.

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#66648

Selective Soldering Issues | 22 June, 2012

We are using Nitrogen from Dewer tanks. We have purchased a generator from On-Site gas that we will be installing in 2 weeks. I guess Nitrogen purity could be an issue, but the company that sells us Nitrogen said it is five 9s (99.999%)

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#66652

Selective Soldering Issues | 22 June, 2012

Is this a new process or are you experiencing a change in results from an already established process?

We have KISS Slective Soldering (2 machines)and we do not have these issues, but we are not doing NC either, we are fully aqueous, using Nitrogen from a generator as well.

Webbing, balls and bridging sounds like it is pointing in the direction of the flux, or your solder pot temp, or a combination of both....

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#66653

Selective Soldering Issues | 22 June, 2012

I have had Selective issues such as yours on two very different Selective Solder Machines. I was able to eliminate these issues by using Alpha EF-9301 wave flux with any SAC305 solder. It's a more aggressive flux, but really made the difference. Another key part of the process is keeping the solder pump and nozzles clean. Also make sure you wipe the flux residue away from your flux jet or pump sprayer. I use DeNatured Alcohol which you can buy at any home improvement store like Lowe’s. I was able to speed up the entire dipping cycle yielding in a higher thru-put. My dwell time is down to less than 1 second with a dip cycle of 1 second.

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tommyg_fla

#66702

Selective Soldering Issues | 29 June, 2012

It sounds like the flux is not holding up during the soldering operations. That would account for the webbing, etc. Also is the problem specific to a certain board type or lot code of boards? Do you think that your boards are outgassing during soldering? Have you tried baking them out immediately before soldering?

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#66704

Selective Soldering Issues | 29 June, 2012

We have not tried baking the boards yet. We are first going to try a new flux. If the flux fails we may try baking.

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#66801

Selective Soldering Issues | 11 July, 2012

never heard about Seho powerselective??

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#67260

Selective Soldering Issues | 14 September, 2012

The Alpha EF-9301 flux worked great! We went from ~4 solder issues per PCB to <1 per PCB.

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#67262

Selective Soldering Issues | 14 September, 2012

Grauen06-Glad to hear it worked out for you. If you adjust your dwell and dip times, you should be able to eliminate your last little issue. Feel free to contact me personally at frankg@fleetwoodgroup.com.

Frank

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