How to Solder

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hagtech

How to Solder
« on: 1 Feb 2007, 12:06 am »
I made me a new movie today.  Not very polished, as I did it in one take.  Just experimenting here with the idea of making useful video clips that might help out DIYers.  This one demonstrates my technique for soldering fine-pitch surface mount chips such as the PCM2704. 

http://www.hagtech.com/media/solder.wmv

jh

steve k

Re: How to Solder
« Reply #1 on: 1 Feb 2007, 12:13 am »
Brilliant!!! :thumb:

Great idea Jim!

I would have never thought of soldering across all the connections and vacuuming away the excess. Now if I could just see the connections without taking my glasses off, and squinting through one of those jeweler's magnifying glasses, I'd be in business! Thanks for the incite.

Here's an idea for another video--how to remove such devices from the same board.  :scratch:

steve k

WGH

Re: How to Solder
« Reply #2 on: 1 Feb 2007, 01:00 am »
Great Video Jim!

I will add this to my collection of tutorials.
I found more soldering tutorial videos at http://tangentsoft.net/elec/movies/
The site has a lot of other electronic articles too.
http://tangentsoft.net/

poseidonsvoice

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Re: How to Solder
« Reply #3 on: 1 Feb 2007, 01:03 am »
Jim,

Excellent video! Action, not words  :thumb:

I just worry about shorting the pins, but I guess the solder sucker should take care of most of my worries.

Anand.

analog97

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Re: How to Solder
« Reply #4 on: 1 Feb 2007, 01:12 am »
Wowwee!!  Great picture.  I asked this question when I saw that small chip installed on the RIPPER.  I was baffled.  Now I think I need some advice on "solder suckers".  I have only used that copper braided stuff to fix my mistakes.  It tends to stick sometimes.  What was the device used in the film?  Thanks. 

TomW16

Re: How to Solder
« Reply #5 on: 1 Feb 2007, 04:28 am »
Great video!  I have always wondered whether my soldering station would be suitable for surface mounted applications and now I have an idea of how to do it.  Thanks!   :thumb:

Tom

hagtech

Re: How to Solder
« Reply #6 on: 1 Feb 2007, 04:46 am »
Quote
how to remove such devices from the same board

Using simple tools, I only know how to destroy-and-remove:

1) Use a razor blade to slice off the pins right at the body of the chip.  Try not to cut board traces underneath.

2) With the plastic body removed, swipe each pin across and off the pad with your iron.  Do one at a time, always go in long direction of pad.

3) Vacuum or braid off any excess. 

Quote
worry about shorting the pins

Sometimes this method leaves a bridge across pins.  I always check with a 10x lupe.  The touch-up swipe almost always fixes this.

Quote
What was the device used in the film?

It's called a "soldapult".  Best $15 you can spend.  I think I get mine from www.allelectronics.com.  Braid is best for cleaning off SM pads.

Quote
soldering station would be suitable

I keep getting more and more lazy.  Used to switch tips for SM stuff.  Now I can use regular tips even on 0603 resistors and caps.  After building so many HAGDACs, it's become second nature.  Hardest so far have been the QFN (leadless) packages.  For them you use a side-swipe technique pushing a solder ball.

jh

BobM

Re: How to Solder
« Reply #7 on: 1 Feb 2007, 03:43 pm »
A great trick there. I also agree about the need for a tutorial on de-soldering technique. I also have only destroyed and removed chips and other surface mount components. I wish I knew how to get these off the board intact, so I could put them back if I need to when what I'm doing doesn't work out the way I planned/hoped.

Thanks,
Bob

hagtech

Re: How to Solder
« Reply #8 on: 1 Feb 2007, 06:03 pm »
Surface mount resistors and capacitors come off nicely with two soldering irons.  That's why you see a pair of them at my bench.

Removing chips with many pins requires more sophisticated and specialized equipment.  I didn't want to spend the money, either.  So I just slice the dang chip off with a razor blade.  In fact, I sometimes do the same with a DIP package.  On a multi-layed board, those pesky ground and power plane connections make it hard to desolder.  For me, I just waste the chip, in return for preserving the board.  Removing pins one at a time is a lot easier.  My technique is to add solder, not remove it.  Get solder and flux on that pin, heat it up and pull out with a small pliers or nippers.  More solder, not less, is the key to prevent damage to delicate pads and traces.

jh

PatOMalley

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Re: How to Solder
« Reply #9 on: 1 Feb 2007, 06:30 pm »
...More solder, not less, is the key to prevent damage to delicate pads and traces.


That is mighty helpful. I just tried it the other way and I can see the benefits clearly now that you mention it. Thanks :thumb:

Chris Muth

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Re: How to Solder
« Reply #10 on: 2 Mar 2007, 01:39 pm »
Nicely done, Jim. I use a slight variation on the theme...
Put small amount of solder on a corner pad.
Hold the chip in place with tweezers and touch the pad to tac.
Put solder on the diagonal pad and push down on the chip with tweezers while soldering.
Reheat the first pad while pushing down; this puts the chip hard to the pads (no gaps).
Slather with solder (so there's enough flux to do the job) as per your nice video.
Use solder braid to remove excess solder.

I have bad luck with a Solda-Pult... tends to remove the trace.
Madell makes a decent hot air station for getting wicked little chips out of circuit without hurting anything.
It's not too expensive if you have to do this stuff a bit.
http://www.madelltech.com/M3-1.html