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ive solder profiles

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I am having some problems with some of my pcbs at ive solder... - Jul 29, 2008 by garyr  

GR@ICS, can you be mo... - Aug 06, 2008 by Chris1963  

GR@ICS, I copied a... - Aug 11, 2008 by Chris1963  

#55736

ive solder profiles | 29 July, 2008

I am having some problems with some of my pcbs at ive solder. We are using an ersa versaflow. It has an automated spot/spray fluxer (Interflux Pacific 2009M) , 1 preheat stage, a leaded pot/nozzel, and finally a lead-free pot/nozzel. Nozzels move, board is stationery.

We are getting an ABUNDANCE of solder balls between the solder joints of certain THT components, mainly connectors. (i.e. DB-50 Dsub Connector)

I am wondering if it is a Delta T issue. Due to the machine only using 1 preheater stage, I imagine it is losing heat as it travels to the nozzel to be soldered (or is losing heat while waiting to be soldered.)and leaving flux on board. I second guess this though because of how uniform the placement of the solder balls are. They are not random.

Anyways, I want to check the board temp and was curious how you guys were gathering data off of your assemblies.

Thanks

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#55738

ive solder profiles | 29 July, 2008

Hi,

for this kind of issues I will always go with the flux first. Are you using only one type of flux? Is it alcohol based or water based? Do you apply a good quantity? Second I will go with the wave shape and speed, and last will be the temperature. I believe in your case you can try more turbolent wave and decrease the Z.

Emil

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#55742

ive solder profiles | 29 July, 2008

We only use one type of flux for Lead Free. It is an alcohol based no clean flux. Is the wave shape and speed as large a factor in ive soldering as in traditional wave soldering? When you say "decrease the Z" do you mean the nozzel or solder height? Also, do you mean increase or decrease the distance between the nozzel and the board?

thanks

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#55796

ive solder profiles | 1 August, 2008

Any other suggestions????

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#55822

ive solder profiles | 4 August, 2008

If you are getting top side wetting, I doubt if this is a Delta-T problem.

It also could be there is a lot of flux on the top side of the board stuck between the connector and the board. This is easily checked by fluxing and not running th eZ axis all the way up. Try it on a board and see how flux is there when you remove the connector.

Other that, check the finish on your board. Glossy finishes ball easier than matt finish.

Has this always been a problem or did someone get a new micro-scope and just started seeing this? We call it the Ozone Hole problem.

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#55824

ive solder profiles | 4 August, 2008

The 2009M is a water based flux and requires more preheating compared to alcohol based fluxes. After checking real chunks advice you might check if you hear sizzling when the solder touches the board (indicator that the water is not eliminated by your preheating).

BTW electronics and water is not a very good match.

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#55825

ive solder profiles | 4 August, 2008

Patrick, you are right. I am sorry. It is a Water based flux. (We have another no clean flux indium 3592 that is used in our leaded process. It is alcohol based and had their base confused)

Chunks, yes, this has always been a problem. If there is too much flux on the top side, how would that give me solder balls on the solder side?

I have suspected the mask material before... We have the same problem at our lead free wave too, but it is way worse on our s e l e c t ive solder.

I have attached a couple of images so you could see what I was talking about. This example is from the wave. It only happens when its single or multiple row connectors/headers.

Attachments:

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#55828

ive solder profiles | 4 August, 2008

After analyzing the pictures I don't think the solder balls are caused by the solder mask. If the problem would be solder mask related the solder balls would only show up on the solder mask but there are also solder balls on the plastic tabs. To me it looks like the areas with a haze are the areas where flux was applied or present. The areas where flux gets trapped easy (connector and plastic taps) are the areas where you get the solder balls. I believe it's either the fluxes you use that produce these solder balls or you are not using the flux manufactures preheat profile or recommended dwell time in the wave for the fluxes.

What puzzles me is that on the bottom of the picture there is a half circle (dark green) that never seen any flux and evidently no sign of solder balls.

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#55829

ive solder profiles | 4 August, 2008

Hey Patrick, thanks. The area that is dark (half circle) is where the camera was. It is the same color as the above. But you may be correct still. I also noticed that the majority of the solder balls were along the "Dark" blue depression around the leads but not all of them.

We are hitting the manufacturers temp in the wave on the top side, but maybe our dwell time is too long. I am wondering also if maybe we are placing too much flux.

Thanks for your feed back.

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#55835

ive solder profiles | 5 August, 2008

Have you tried the alcohol based flux on your ive yet? (even if it isn't specd for leadfree). Water based flux seems more prone to solderballing.

edit: why is sel ective changed to ive and alte rnative changed to native?? censorship for innovation on the smtnet?

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#55866

ive solder profiles | 6 August, 2008

GR@ICS, can you be more specific about your up in the Ersa machine please?

Nozzle size, pump rate (%), and is your machine equipped with monitors on the solder pots? We have the same machine it sounds like, however we run Pb-Free in both pots.

I know that we have had similar problems in the past but I am not exactaly certain of how it was resolved. I'm not the Ersa programmer in our plant, however, I do maintain it on third shift when necessary. If you like, email me and I could hook you up with our programmer who could help you troubleshoot your problem with the solder balls. The reason I ask about the nozzle and flow rate and such is that the programmer here will be asking those exact questions when I ask him about your problem.

Good luck!

Chris

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#55869

ive solder profiles | 6 August, 2008

We have a 3/6 Nozzle We do have monitors. One of our pots is leaded, the other is lead free.

Our average wave height is ussually around 50%.

Also, do you have any or found any benefits to removing nozzels at the end of your shift. I recall you saying you ran 3 shifts, so I am not e.x.p.e.c.ting that this is the case for you.

Thanks

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#55908

ive solder profiles | 8 August, 2008

I would have to second the opinion on the water based flux. If you don't want to deal with the solder balls, switch to an alcohol based flux. Unless you have a board that takes a while (water based tends to stay active longer), alcohol is easier to use.

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#55925

ive solder profiles | 11 August, 2008

GR@ICS,

I copied and pasted all of the thread here including the photos and sent them to our programmer for the machine. I will get back to you if he doesnt come on here himself and respond to your problem.

Hopefully we will have an answer for you in a day or two...

Chris

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#55941

ive solder profiles | 11 August, 2008

Too much flux will spatter and can leave balls on either side.

From your pix you may too little flux. Try turning up and see. Also try hand applying your alcohol based flux and running through. Will take away a few question marks.

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#55957

ive solder profiles | 12 August, 2008

GR@ICS:

Are you drag soldering or point-to-point soldering? Keep in mind. Drag soldering mimics wave soldering. Molten solder is contacting and dragging across the solder mask. Keep in mind, too, that "semi-matt" or "semi-gloss" will also tend to solder ball, so just 'cause the board ain't glossy, if it's even "semi-glossy" it'll solder ball.

Yes, try to play around with flux deposition. You can do that 2 ways on ERSA...through your Flux percentage setting or your flux drag speed. Contact time (less is better) also plays factors in solder ball mitigation.

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#56076

ive solder profiles | 20 August, 2008

I would like to thank everyone for their help on this one...We havent had the board back at S E L E C TIVE on this yet, But I will keep all updated (if there is the care for it...

Thanks again

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#56077

ive solder profiles | 20 August, 2008

Let us know what the �sol� was we can all learn from it.

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#56305

ive solder profiles | 2 September, 2008

use the 2009MLF from Interflux it will take away your solder balls. this is a known issue.

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