What is better and safer for soldering SOIC and TSSOP, butane micro torch or the heat gun?
Another question is what solder paste is best for fine soldering? I assume some low-temp one, right? It doesn't have to be lead-free, as I assume.

 

1) Heat gun, if you insist. Although, I just use a temperature-regulated soldering iron. With a torch, you need to be concerned about which part of the flame you are using -- ever try to solder a pipe using one where you heat the solder rather than the joint? With the devices you mention, you will have a difficult time just heating the joint, not the solder.
2) The paste I have seen is generally no different than the solder I use. You do not need a special low-temp paste.

John

 

1) Heat gun, if you insist. Although, I just use a temperature-regulated soldering iron. With a torch, you need to be concerned about which part of the flame you are using -- ever try to solder a pipe using one where you heat the solder rather than the joint? With the devices you mention, you will have a difficult time just heating the joint, not the solder.
2) The paste I have seen is generally no different than the solder I use. You do not need a special low-temp paste.

John

I agree. A heat gun will give you a more uniform heat, and there is also no chemical reaction going on that could contaminate crucial components. (I do use a butane torch for outdoor work, but on much less delicate parts(.

Eric

 

Thank you. As for paste, there's a great variety of them. Silver, lead free, etc. I think I'll take some regular lead-tin, preferably with no-wash flux. Any particular recommendations?

 

You can look for the ratio 63% lead & 37% tin as having the lowest melting point. Extra points for the addition of 2% silver (makes the joints very smooth and shiny, very slightly improves the electrical properties).

If I could recall the article, I would point you at the one that was from a man who had managed to create a stencil out of thin plastic. He positioned it over the lead traces and used a squeegee to wipe solder paste across. The method produced very accurate results.

This is not that article - http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=58 - but has an idea. You can always Google "solder paste stencil" for more.

 

Thanks! I have ordered what I need from proto-advantage.com, including paste, boards, and a stencil kit.

 

You can look for the ratio 63% lead & 37% tin as having the lowest melting point.

I think you mean 63% tin and 37% lead (http://www.efunda.com/materials/solders/tin_lead.cfm).

John

 

Quite possibly.