Author Topic: Leadfree solder with 138ºC melting point  (Read 2228 times)

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Offline ablacon64Topic starter

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Leadfree solder with 138ºC melting point
« on: February 24, 2014, 02:18:04 am »
I crossed by this video and it seems amazing. Anyone using it? Is it reliable?



I think it would solve many problems specially with BGA soldering.
 

Offline IanB

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Re: Leadfree solder with 138ºC melting point
« Reply #1 on: February 24, 2014, 02:41:31 am »
As with many things, if it seems too good to be true, it probably is.

If you read up on tin/bismuth solder alloys, you will find there are enough downsides that it is not found in regular use.

Approach with caution.
 

Offline JuKu

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Re: Leadfree solder with 138ºC melting point
« Reply #2 on: February 24, 2014, 11:51:43 am »
As with any  soldering procedure, you must get your process right. But when you do, it is as good as other methods. When you go to details, all solders have good and not so good properties. Notable downsides for bismuth alloys have low surface tension, so parts don't self-align as nicely and fall off more easily if doing double side reflow without glue. Also, those used to be expensive and they don't tolerate lead pollution (but you are supposed to keep leaded and non-leaded separate anyway), but those issues shouldn't be problematic nowadays.
http://www.liteplacer.com - The Low Cost DIY Pick and Place Machine
 

Offline ablacon64Topic starter

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Re: Leadfree solder with 138ºC melting point
« Reply #3 on: February 24, 2014, 01:06:18 pm »
I could not find many information about what would be the behavior of that alloy on soldering high density (as in small pitch) BGA chips like an AMD North Brigde. What's the thermal expansion, if it's subject to cracks, etc...

One of the bigger problems I find when reworking BGAs is leadfree high temperature. I guess it would be really nice to have such a low melt point solder.
 


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