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01005 components and reflow profiles

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#66130

01005 components and reflow profiles | 9 April, 2012

Hello,

We're building some boards with 01005's and the only issue we are running into is the solder is not reflowing. It's the damnest thing, we are having no issues with the printing process or placing the components, the two areas we thought we would run into all of our issues. We are using a water soluble sn63/pb37 type 4 paste and I have tried numerous profiles that I created using the KIC2000 thermal profiler and the closest thing to a good wetted solder joint didn't occur until I was reaching lead-free solder temperatures and I was way out of spec according to the TDS.

Anyone have experience with 01005's and soldering issues? Any input would be greatly appreciated.

Thank You

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#66131

01005 components and reflow profiles | 9 April, 2012

I forgot to add that we are using a 3 mil stencil. It seems like to me that may be there isn't enough flux left when we reach liquidous?? About half of the solder spheres do melt and wet on each pad, but the top half of each solder joint is just the solder spheres that will brush off easily. I was thinking the next test board I run that I will keep the soak temperatures down and then hit it with the high reflow temps. I am concerned about tombstones then, among other issues that could arise.

Any suggestions would be appreciated.

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#66132

01005 components and reflow profiles | 9 April, 2012

I haven't worked with anything as small as 01005s, but something you didn't mention is the %metal of your paste. I just switch from 90% to 89.5% (AIM NC257-2) and could tell the difference. Just an idea...

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#66133

01005 components and reflow profiles | 9 April, 2012

Interesting thought. Our paste is 89.2% according to the data sheet I have, but it still might be worth trying the 84-86% syringe blend. Thanks for the suggestion.

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#66134

01005 components and reflow profiles | 10 April, 2012

you are seeing a typical issue that is caused when such small volumes of paste are printed....there are several reasons for it..the tiny amount of flux in the small deposit becomes exhausted much quicker then it does in a larger deposit ( the flux may bleed away from the powder when in the reflow oven). If you have no fluxing action left when the solder is above its melt temp then the solder spheres will not flow together. The flux is the medium that transfers the reflow oven heat to the paste so if there is little flux and it is drying out fast then the solder powder doesn't get the heat transferred to it efficiently. Trying a paste with more flux may help reflow but will give issues with printing. Ask your paste supplier for a paste with a thermally stable flux that is proven to reflow ultra small deposits.

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#66156

01005 components and reflow profiles | 13 April, 2012

*Like*

(There should be a way to "Like" or "Dislike" replies so that other Engineers can agree or disagree with a response. Doens't this sound like a good idea?)

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#66158

01005 components and reflow profiles | 13 April, 2012

Hey Frazzled, you mean you don't prefer the back and forth flaming wars when someone disagrees with an opinion?

How about "Agree" & "Disagree" for starters. Later we can add "YGTBK"(you got to be kidding), and "WP" (Wrong Planet)

Great idea Frazz

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#66159

01005 components and reflow profiles | 16 April, 2012

*Like*

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#66168

01005 components and reflow profiles | 16 April, 2012

What is that garbage.

How about you add flamer to like and dislike. I would have used it at least 3 times in this thread alone.

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#66169

01005 components and reflow profiles | 16 April, 2012

6 or 7 replies and 3 *flamer* ratings already?

And here I thought this was good info above...

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reflow oven profiler

Reflow Oven