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First attempt at Surface mount soldering

Posted: Thu Jan 15, 2009 5:46 am
by longracing
Here's a little pic of my first attempt at SMT.
It's a logic probe kit that uses a PIC10F202. Indication is with a red LED (1), green LED (0) and an amber LED to indicate a change in logic level.
I found good old blu-tack was useful to hold the parts in place for the first solder join.
Image

The only trouble with the kit is finding a clear pen casing that this fits in.

Re: First attempt at Surface mount soldering

Posted: Thu Jan 15, 2009 11:22 am
by jharvey
About SMT soldering, check out this page.

http://www.zianet.com/erg/SMT_Soldering.html

This guy recommends the use of some semi special hardware. In my opinion the solder paste makes a world of difference. I'd recommend getting some solder past from this fellow, or where ever you can get it. I think you'll find the SMT soldering is actually easy, easy if you have the solder paste that is.

Re: First attempt at Surface mount soldering

Posted: Mon Jan 19, 2009 4:34 am
by longracing
I'll agree the solder paste or a flux pen would make the job easier.

Over all I still found SMT easy and would like to use it a bit more. Maybe in my next work project. 8-)

Re: First attempt at Surface mount soldering

Posted: Mon Jan 19, 2009 5:01 am
by toalan
I have only used 1 type of paste, I am not sure if better paste is available.

I found that solder paste is lumpy, air bubbles get into the syringe, and that makes applying small amounts of paste uniformly very very hard. I am not sure if there is smoother paste out there, I buy my paste from circuitspecialists. Paste also has a tendency to turn into an even more of a lumpy mess over time.

Using sold core solder and tinning the pads is easy and very quick.

I do 99% of my SMT work with a fine iron and sold core solder. I only use the hot air tool at the very end, mostly to make the board look pretty. I apply lots of flux and then use the hot air, it does a good job at straightening crockedly places resistors/caps and makes most of the ugly joints look clean.

If you do not have a hot air tool and paste, I do not think you are missing out on much. The exception being that desoldering SMD components with more than 2 pads is virtually impossible without a hot air tool.

My opinion is that for fine SMD work a nice fine tipped iron and a nice set of tweezers is more important than a hot air tool and paste.

http://www.dealextreme.com/details.dx/sku.7042
That is what I use for tweezers, that are fantastic.

http://www.dealextreme.com/details.dx/sku.4711
That paste is dirt cheap, I have not used it but I am going to get some once my current paste gets used up or goes totally bad.