[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

RE: Surface mount component holder

Solder in the mouth is not a good idea. 

Here is how we do surface mount discrete:
1. Put water soluble flux on the pad.
2. Place the component on the pad, but do not align it. Just place it so the
component touches the pads.
3. Put a little bit of solder on the solder-gun's tip (first hand).
4. Hold the part down with your favorite set of tweezers. Don't hold it from
its sides, just use the tip of the tweezers to keep it from moving. If you try
to hold it from the sides the muscles in your hand will cause it to
shake. It's the same muscles that work against us when we do sharpshooting.
5. Apply the solder to one of the pads. Due to the flux, the solder should get
sucked onto the pad.
6. Now that one side is tacked down, you can remove the tweezers, get some
more solder on the tip and go for the other side.
7. In order to align the component properly, we used another solder gun to do
what we call "solder reflow". Take to solder guns. One in each hand, and heat
both pads at the same time. Due to surface friction, the component will
"pop" into place. This technique was taught to us but Chuck Green N0ADI -
thanks Chuck!
8. you are done! and only used two hands - no extra appendages needed!

BTW, we also have a fan to carry the flux fumes away. Some of my guys said it
gives them headaches, it doesn't to me, but I guess my brain is already fried!
Also, I make sure that the guys are well fed before they do SMD work, hungry
people tend to shake. Pizza does it really well for students :-) (After
extensive research it turns out that Papa-Johns is better than Pizza-Hut for
Assi 4X1KX/KK7KX

  Assi Friedman, ASUSat Program
  Tel: 480-844-1458 (home)
  Tel: 480-965-2859 (Office)
  Tel: 480-965-2474 (ASUsat lab)
  Fax: 480-965-0277 (ASUsat lab)
  Email: assib@asu.edu
  Home Page: http://www.public.asu.edu/~assib
  ASUSat Page: http://nasa.asu.edu

Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org