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Solder paste Thawing

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Solder paste Thawing - Feb 13, 2006 by sumxp  

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Solder paste Thawing - Feb 13, 2006 by RFredericks  

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Solder paste Thawing - Feb 13, 2006 by Steve Thomas  

Solder paste Thawing - Feb 14, 2006 by Sr.Tech  

Solder paste Thawing - Feb 14, 2006 by

#39634

Solder paste Thawing | 13 February, 2006

Certain paste mfg specify 6 hours paste thawing time to normalize the temperature.
I am using solder paste softerner to spin the paste taken out from fridge for 9 minutes and measure the paste temperature in jar.It is around 26'c(same as the ambient temp).My question,is this the correct procedure?I use it immediately after spinning.

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TZ

#39639

Solder paste Thawing | 13 February, 2006

Why not use microwave oven, it would be faster ?

Be careful, rheology and all paste's characteristics are strongly dependent from the "not stressing" reaction moving from low temperature to Room Temperature.

Best regards

TZ

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#39643

Solder paste Thawing | 13 February, 2006

I'd be curious if a microwave would activate the flux. I'd also suspect that the metal content of solder might just give you that excellent "microwave+fork" effect. I can see this R+D failing miserably.
-Russ

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Chunks

#39649

Solder paste Thawing | 13 February, 2006

Sure, if your solder joints are reliabale after reflow. TZ is right about watching how you mix it, but 9 minutes sounds like it's not moving too fast. What brand of mixer are you using?

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#39658

Solder paste Thawing | 13 February, 2006

You can put metal in a microwave (at least you can mine) as long as it doesn't contact the enclosure, but there's no way you'll get consistent heating of the volume in a microwave, even if it employs a "carousel".

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#39679

Solder paste Thawing | 14 February, 2006

Good morning,

Solder paste softeners are designed to allow solder paste reach ambient temperature during shorter time period (only 5-10 minutes instead of hours). You are preparing your material in right way. No reason to worry.

BR, Pavel

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#39687

Solder paste Thawing | 14 February, 2006

Pardon me for being so bold, but I still cannot understand to this day why solder paste thawing is an issue.

I am not sure what types of paste you all are using but it has been my experience that the only thing you gain by refrigerating is 3 months extra or so shelf life....

It has also been my experience that refrigerating paste causes more problems than it prevents.

So before you go spending a bazillion dollars on some plasma arc accumulator/solder paste homogenizing device, I suggest you ask your paste manufactuer what you are actually gaining by refrigerating.

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Chunks

#39694

Solder paste Thawing | 14 February, 2006

Well, you don't want your paste to spoil! It'll give it a bad aftertaste.

Actually, we refrig our paste mainly cause our stock room gets rather on the toasty side. Jars left un-friged will cause the metals to sink and leave a puddle of flux on top. Now you can remix this back in, but it's one more variable that depends on an operator. We try to take such variables away from our operators. So since we need to refriderate other materials to slow their cure, we also keep the paste in there. We simply take out a few jars at the begining of the shift for the NEXT shift. 8 hours in an unopened jar works well and requires hardly any mixing.

Now, Captain Nabbers needs to inquire how I can get me mits on one of dem plasma arc accumulator/solder paste homogenizing devices?

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