how to use SOLDERING PASTE cream ?

[slackeruser]

Hi
I have this one (in picture)
**broken link removed**

Uploaded with ImageShack.us
**broken link removed**

Uploaded with ImageShack.us
my question is : what is this cream for and how to use it ?
thanks

 

[3v0]

Looks like a flux.

 

[KeepItSimpleStupid]

It doesn't look like soldering paste and when I went looking, ebay showed these results: **broken link removed**

AND

called it solder flux paste.

Flux helps clean surfaces and helps parts stick. It is usually cored inside of some wire solders. It's used in surface mount technology primarily for large parts like a USB connector when using solder paste. It's dabbed on the USB connector tabs, so it more likely bonds to the screened solder paste.

Solder paste is like shipped in a cold pack. Flux would not be.

Also see:

http://www.youtube.com/watch?v=c_Qt5CtUlqY&feature=results_main&playnext=1&list=PL73D0ABDA85D1234E

Which shows how to hand solder a QFN package with flux and wire solder.

 

[slackeruser]

thank you

 

[ElectroNewby]

I always use this. I put some on the parts I want to solder with a toothpick and bring a melted drop of tin on them, the drop reacts with the wax and places itself exactly where it needs to be. I know it's not a by-the-book trick but doing this got me a 100% in my soldering class (the only one doing this and getting this lol) but I know I'm not alone, the engineer working in the electronics of my father in law's plane did the same the other day and he works on the planes of the military base.

On the other hand, I can't just heat a component with my soldering iron and try to solder with the tin wire alone.. it works but not near as round and sexy

 

[KeepItSimpleStupid]

I remember one Surface mount IC I replaced in a car radio and I didn't believe how easy it was to solder with the part upside down after tacking the corners.