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Lead Free Dross

Views: 2818


CG

#38974

Lead Free Dross | 11 January, 2006

We have recently started using lead free solder on our wave. The dross accumulates rather quickly. The dross flakes (tin oxide?) are light enough to sometimes fall or float into the main wave. What kind of quality concerns are there if the dross is mixed into the solder joint on the bottom side of the board?

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Cmiller

#38980

Lead Free Dross | 11 January, 2006

What alloy are you using in your wave? SN100, SAC305, SACX?

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CG

#38981

Lead Free Dross | 11 January, 2006

SAC305

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Cmiller

#39000

Lead Free Dross | 12 January, 2006

We tested SAC305 in our selective solder machine and found the dross production made it an unnaceptable choice of alloy.

Personaly, I cant imagine dross in a joint being a good thing but if it is a very small amount and does not occur very often, you might be able to let it go. Long ago with some old wave solder machines using tin/lead we used to get little specs of dros coming up in the pump and sometimes getting in the joint. We left them alone figuring re-work was worse than the dross. We never got any complaints and now-about a decade later, have not seen anmy boards come back with failures. If the flakes actually protrude from the joints, I would re-work them.

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CG

#39001

Lead Free Dross | 12 January, 2006

Thanks very much for your response. It has been very helpful.

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sarar

#39010

Lead Free Dross | 12 January, 2006

If you want to try and reduce the dross, there is a really interesting product out there that you might want to examine called MS2 - it's developed by P Kay metals out in LA, and is known to completely eliminate dross in lead free processes. I'm not sure how available it is yet to the general market, but here is a link to their website - http://www.ms2technologies.com/ I'm in no way affiliated with the company, but I do know the owner through business, and have seen the product in action, and its pretty amazing.

Sara Rice Foresite Inc. www.residues.com

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Cmiller

#39014

Lead Free Dross | 12 January, 2006

It really does not say what it is. We used to use oil on our wave, it even had a built in pump and drain in the pot to keep it fresh and at the right level, worked great, made a hell of a mess. A big no-no for no-clean. I think most people got away from that practice 10 years ago or so.

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#39019

Lead Free Dross | 12 January, 2006

Sara, this MS2 stuff sounds great, but just wondering what kind of residue is left behind on the PWB. Is it kind of like the oil injection days of old? Thanks, FrankP

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#39675

Lead Free Dross | 13 February, 2006

Hi all, I will do my best to answer questions on MS2 here. I will try to check back at least every other day.

MS2 is a new process chemical. It is not an oil or powder. It does not leave a residue; it does not mix with the solder. All SIR testing is good and we have done a lot of it. We have a great deal of reliability testing and have been doing production testing for months that is how the word got out. The product was just formally announced. We are in the process of setting up our distribution partners but we are not in full scale sales as yet. We are not supplying samples without being able to come in and show you how to use it. As you might expect we are overwhelmed by requests right now. We do have a data sheet, MSDS forms for both formulations and reliability and economic data. The installation and maintenance guide will be ready soon. The material totally eliminates dross for all alloys, leaded and lead free. I gave a paper on this material at APEX and will give another at the lead free conference in Santa Clara in a few weeks.

As I stated, I will try to keep up and monitor the forums here and answer your questions.

Dan (Baer) Feinberg

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#39680

Lead Free Dross | 14 February, 2006

I saw this MS2 in action at APEX on my friend's lead free wave during the show. Very impressive results. Appeared to simply pool in one specific location at the end of the pot...away from the wave completely...although I wasn't sure if this was due to the design of the pot or the MS2 itself. I think as long as it isn't introduced in the wave and therefore introduced onto the board it looks like a great product.

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#39683

Lead Free Dross | 14 February, 2006

Rick, You are correct, it does need the solder dross in the pot to mirgate (pool) to an area. Some machine mfrs. are doing this already, others don't. For those that don't, there is a modification offered. It absolutley does not get into the wave. It only sits on top. They have done the proper testing to prove it is not in the solder.

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#41191

Lead Free Dross | 25 April, 2006

I tried the MS2 after listening to the claims from PK Metals. It was a distaster. What a mess. Everything was coated in a black soot and scum. We nearly lost a customer because the quality went down and we had so many problems. Steer away from this. What sounds too good to be true usually is.

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Baer

#41262

Lead Free Dross | 28 April, 2006

So what is your company? P. KAY is not aware of you or of this situation and we would like to discuss it. The only way that you could have what you claim is if the maintenance were not done and if spent MS2 were left on the solder pot for days. Like any process chemical if you do not maintain the process or install or run it correctly you can have a problem but what you describe could only happen with gross neglect of the process. If this had happened and we were called we would have sent someone to train the operators to be sure it was running correctly. Hundreds of thousands of dollars savings should be worth a little attention to detail. Contact me either privately or here and we will be glad to get you running correctly. We can not help if we have no idea who you are. I can also put you in touch with a numbers of others who are running MS2 and saving a bundle on solder purchases and also seeing improved quality.

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#41359

Lead Free Dross | 3 May, 2006

I am based in Nogales and I have also tried the MS2, I was told to immediately cancel my trials, It did reduced the build up of dross but the mess it made to the wave and the surrounding areas was very bad, Everything was coated black and the smell and fumes were very strong, Also we have a increase in quality issues and managment put it down this this, As soon as we removed it from the process the quality issues went away, I found that when you look at the cost of this per lt and the cost of shipping back to the supplier the numbers are not good.

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Harry

#41470

Lead Free Dross | 10 May, 2006

This stuff is great! Remember to do the maintenance correctly and you'll have great results. I've been using for about 2 months and reduced my solder purchases nearly 70% with my 63/37. I will be using the lead free version in my SAC 305 machine as soon as I get it up and running.

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#41483

Lead Free Dross | 11 May, 2006

Harry is correct. Like any process chemical it has to be installed and maintained properly. It is not hard to do but it is important that it be done correctly. After all it is easy to plug in a light but if you do not do it it will not light up. Does that mean that you continue to burn a torch because you think electric light's do not work? In wave solder machines, when installed and maintained properly MS2 works. If you need more information go to the web site ( http://www.pkaymetal.com) or e mail me.

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Reflow Oven

SMT in-printer dispensing