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soldering parts

Posted: Tue May 03, 2005 1:02 pm
by wayward717
greetings

is there a possibility of soldering parts on ordered pcb boards
e.g. like the molex connector of gm862...

of course with added cost?

thank you

Posted: Tue May 03, 2005 2:37 pm
by sparky
Ugh. We'd have to charge so much for setup and testing... Sorry, I don't think we can handle business like this :cry:

Why not learn? We hand soldered that connector 80-90 times before we went to stencils and solder paste. :twisted:

-Nathan

Posted: Wed May 04, 2005 10:49 am
by wayward717
ok ... can you please suggest a soldering guide for such small pitch smt?

Posted: Fri May 06, 2005 5:07 am
by lynchzilla
There's a very nice SMT soldering tutorial at the Solicon Laboratories web site (they manufacture SparkFun's USB-to-UART bridge).

Here's the link:


http://www2.silabs.com/public/documents ... /an114.pdf

Posted: Fri May 06, 2005 5:34 am
by upand_at_them
That PCB vise is cool. Who carries those?

Mike

Posted: Fri May 06, 2005 11:54 am
by donblake
upand_at_them wrote:That PCB vise is cool. Who carries those?
It looks like the PanaVise product. My local electronic store carries them. So does Digi-Key and Mouser. From the picture, it looks like the Electronic Work Center (324). You can also purchase base, holders and accessories separately.

Don

Posted: Fri May 06, 2005 8:57 pm
by Norman
hey, thanks for posting the link to that guide! That's very helpful.

Posted: Sat May 07, 2005 1:33 am
by wayward717
GREAT Tutorial

THANK YOU A LOT :lol:

Posted: Sat May 07, 2005 11:04 am
by MGP
That was a good tutorial and Panavises are great -- I have two of them in my workshop and use them constantly.

My best advice to anyone getting into electronics now (or planning to stay for a while) be it hobbyist or professional is to buy a hot air rework station. Since I bought mine about 2 years ago SMD is no longer a major challenge. That, along with a good temperature controlled soldering station will cover pretty much all the bases (except BGA and that's mostly an inspection issue).

If you don't have a good temperature controlled soldering iron already then a combo hot air rework-soldering iron station like the HR8502 that Sparkfun sells is an excellent investment, a bargain really -- $175 and it will last you for years and years.

I wish Sparkfun had been selling them a couple years ago as it would have saved me some money. Even though I paid a bit more for my hot air rework station elsewhere it was definitely money well spent and has paid itself off in time and frustration saved.

Posted: Sat May 07, 2005 3:09 pm
by nall
MGP wrote:My best advice to anyone getting into electronics now (or planning to stay for a while) be it hobbyist or professional is to buy a hot air rework station.
I am just starting to get my feet wet with SMT. Is there any sort of tutorial (like the excellent one above) that addresses when/how to use a hot air rework station?

Posted: Thu May 12, 2005 8:15 am
by moorejl
nall,

I just received a 850D from Nathan and the universe provided me with an opportunity to use it the day it arrived :o

Without hardly reading the instructions I was able to remove two SOT-23 transistors from 10 boards in about as many minutes, awesome! (they were suposed to be SOT-23 diodes :oops: )

Adhoc procedure for correcting my mistake:
1. Set temp to about 350C (or midway on temp knob)
2. Set air flow to near minimum (don't want to blow away small parts)
3. Put on small tube nozzle
4. Hold 1" above part and preheat about 5 seconds
5. Lower nozzle to about 1/8" above part and watch the solder melt on all pins at the same time in a few seconds.
6. Quickly grab part with metal tweezers and remove
7. Clean up excess solder from pads with solder wick and soldering iron
8. Add fresh solder paste
9. Place proper components
10. Preheat 5 seconds at 1"
11. Reflow at 1/8"
12. Clean off flux (I use water soluable paste and the flux is corrosive)
12. Inspect (looked as good as new)

This thing is also a mad heat shrink tubing gun. Set temp at min setting (160C) and air flow at 1/2 setting and you can shrink the tubing without worring about overheating it using the same small nozzle.

Even though I bought the expensive one, it was worth the price of admission just to watch the solder melt on all pins at te same time.

Jamie

Posted: Thu May 12, 2005 8:29 am
by nall
moorejl wrote:nall,
8. Add fresh solder paste
thanks for the response! is the amount of solder paste you add more art or science? can adding too much be fixed with solder wick?

Posted: Thu May 12, 2005 3:38 pm
by sparky
He's a purist ;) Here in the shop, Ben can hot air off an IC, rotate it 90 degrees, and hot air it back into place in 20 seconds. No extra paste, no wicking.

Why the IC was put down incorrectly in the first place is another story (Pin 1 goes here!!).

You can also reball the pads with regular solder if need be. This adds flux and helps everything flow when re-airing.

-Nathan

Posted: Thu May 12, 2005 9:02 pm
by moorejl
sparky wrote:He's a purist ;) Here in the shop, Ben can hot air off an IC, rotate it 90 degrees, and hot air it back into place in 20 seconds. No extra paste, no wicking.
-Nathan
I might be tempted to try that with an IC, but the SOT-23 is so light, that you would need to keep it in place with tweezers while heating so it doesn't blow away. I find the paste does a good job of holding the tiny parts in place. I am getting old and its hard to keep my hands still enought for the tweezer trick. :)

To answer your question, the amount of paste is not too critical, I use a syringe and a 23 needle which makes it easy. An you can mop up extra with wick.