Solder type?

[zvacman]

I was reading the instructions on one of my DIY kits and it specifies using 63/37 solder and NOT to use 60/40. Is there any validity to this that can be backed up with an explanation? I have used 60/40 for over a decade on PCB's and never had an issue. I live in a small town and haven't been able to locate any 63/37 solder anywhere. I could order some online but I was really hoping to build some controllers this weekend. Input?

Z

[LOR Staff]

If you have 60/40 and are an experienced solder head, you can use the 60/40.  

 

63/37 has a better crystalline structure when it sets up (goes from melted back to solid) and is more forgiving for neophytes in that regard.   You'll get less 'cold' joints with 63/37 if you are a newbie.  Basically, 60/40 has a larger 'plastic' range - that is a range of temps where things are not quite liquid, but not quite solid either.  Moving a component during the plastic phase will change the crystal structure and result in a cold joint.  With 63/37 the plastic range is very small.  

 

You won't see the difference when you are soldering, since we are talking down on the molecule scale.

 

63/37 also has a lower melt point than 60/40 allowing you to get on and off the pad quicker than 60/40.

 

I stick with my 60/40 since I've been using it for as long as I can remember.  However if you are not an expert, you may want to use the 63/37.

 

FYI, our kits come with solder.  Why are you not using it?  You can also easily find it online:  http://amzn.to/1UdZSYh

[zvacman]

DevMike,

I do use it when building one of your kits, other companies aren't so generous. I'm building a couple of E682's right now.

Z

[LOR Staff]

DevMike,

I do use it when building one of your kits, other companies aren't so generous. I'm building a couple of E682's right now.

Z

 

Sorry, I was confused since you posted this in the LOR DIY kit area.  Since this isn't an LOR kit question after all, I moved the topic.

[zvacman]

Sorry, I was confused since you posted this in the LOR DIY kit area.  Since this isn't an LOR kit question after all, I moved the topic.

Sorry for the mis-post I just thought it was a good fit in the DIY area.  30 lashes with a wet noodle are in order.

 

Z

[Ed K]

60/40 works fine, and I'd stick with it.  The advantage of 63/37 is that it melts at one specific temperature only (technically, within a much narrower range than 60/40).