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AIM SN100C Solder paste

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#40863

AIM SN100C Solder paste | 6 April, 2006

Last week I had the opportunity to get a sample of AIM SN100C solder paste. The SN100C paste was very nice to work with. My initial observations was that the paste had a very light odor, much less than the Alpha UP78 paste that we are currently using. The paste was mixed before being applied to our stencil and was run without any changes to the print pressure or speed on our SMT 2020. The paste adhered evenly to the stencil blades and according to my SMT operator seemed to roll better than our regular paste. The paste deposit on our pads was crisp and resisted slump for more than 30 minutes while we set up for the next job. This time is artificially long for our process. Usually paste won't sit on a board for more than 10-15 minutes max. Our normal stencil is a 5mil stainless steel laser cut electro polished foil. IC lead apertures are reduced to 90% size and most other apertures are home plated, unless otherwise noted. I developed a ramp soak peak profile similar to the graph that was provided me; the assemblies were run through our five zone 1500 Heller. My peak temperature was 250C. Instead of a 3.5 minute run time as suggested I ended up with a 4.5 minute profile. The re-flowed results were very encouraging. The solder joints were shiny with the solder migrating out to the edge of the pad. The solder appears to be very robust in nature. A little bit of destructive testing demonstrated that there was much less voiding than the SAC305 alloy and that it would take considerable force to pry off the component. Upon visual inspection I found that the solder re flowed to the edges of the pad and produced good heel, side and toe fillets. The appearance was smooth, shiny and uniform. One intersesting fact to note is that compared to the Kester EM907 paste the peak temperture is recommended to be 240-245C on the AIM reflow profile. This is right between 235-255C that is published on the Kester data sheet. All in all, I liked working with this alloy I wish that I had this solder a year ago when I approved the EM907 from Kester. I think that that we may have opted for the SN100c instead.

Jay Brower

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RDR

#40864

AIM SN100C Solder paste | 6 April, 2006

this is all good jay but would WML have to say about this paste?

I'm gonna wait for his response before I do anything!

I am bringing in some samples of this soon to try for myself. I have a part that the manufacturer says to run with a paste with no silver(?). They say it wicks up the terms and causes interface problems(S) its a BGA socket.

Currently running Alpha OM338 and like it very much.

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#40865

AIM SN100C Solder paste | 6 April, 2006

I'm just dying to hear. I think this past will be a contender for us, I'd use it but I allready commited to using the Kester EM907. Maybe after the first of the year I'll look at switching to this paste. Ive never heard of a problem like that, but my plant doesn't do BGA's yet. I convinced the engineers that BGA in assembly would be a better idea AFTER moving to lead free assembly, not during the transition. Jay

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RDR

#40866

AIM SN100C Solder paste | 6 April, 2006

You're a smart man Jay!

I'll let you know on the paste

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#40887

AIM SN100C Solder paste | 7 April, 2006

I still have half of a 500 g jar of this paste left. I'm going to give it another shot, but my first experience was not so wonderful. Everything was great until we reflowed it. Our profile matched AIM's recommendation, as far as I can see. The chip caps soldered fine, but the solder did not wet at all to the SOTs on the board. It acted like the leads were stainless steel. I only had a limited number of PCBs to work with so I didn't mess around with any more boards. We switched back to a SAC305 paste and oven recipe and it wetted beautifully.

If anyone is curious, I can email you some pictures of the bad joints and the profile we used. Suggestions and advice are welcome, since I'm not really an SMT process wizard just yet.

Here's the thing that bothers me... The day I had this problem I emailed the profile and pictures to our AIM rep asking for advice. That was on 3/24! Never heard back from him. On 4/4 I emailed AIM directly, and never heard back from them. Good support and service are as important as a quality product. As far as I'm concerned, I'm not going to buy any of their solder OR tooth paste.

As far as odor is concerned, for our Pb-free paste evaluation we only considered SAC305's. So I have smelled quite a few SACs recently and of all the SACs I have smelled, I thought that MRI's SAC smelled the best. The SN100C sample was only considered after it was determined that our Pb-free wave will be filled with either SN100C or SnCuCo.

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#40893

AIM SN100C Solder paste | 8 April, 2006

Hilarious cuculi...

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#40920

AIM SN100C Solder paste | 11 April, 2006

Cuculi,

I'm sorry to hear this. AIM prides itself on our service and support, but clearly something fell through the cracks here. If you would, please contact me offline at dsuraski@aimsolder.com and I will make sure that you receive the support you need.

Thanks, David

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#41805

AIM SN100C Solder paste | 25 May, 2006

I find it hard to believe that AIM never contacted you either by the rep or directly. I switched to AIM solder 4 years ago after using several of their competitor�s pastes for the very fact that the products were as good but Aim�s technical support was better.

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#41808

AIM SN100C Solder paste | 25 May, 2006

AIM contacted me the day after I posted this on SMTnet.

I have still not heard anything back from my AIM rep.

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#41839

AIM SN100C Solder paste | 26 May, 2006

250C peak temp seems very high for components. Thermal damage, which is latent like ESD damage, can occur on components at temps as low as 235C. Looking at component specs to see what the max temps are is a good idea I think when doing Pb Free trials on your products, then select a solderpaste that meets these max temp requirements.

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#41842

AIM SN100C Solder paste | 26 May, 2006

Hey Pete. I agree, 250c is a bit on the high side, I'm working with the EM907 paste and getting great results witha top end of 230-236. Best of all, our CEO had a very dificult time telling which board was lead free and which was lead. Have a great day, Jay

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