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Science Forum Index » Electronics - Basics Forum » Solder braid: width?...
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| aleksa... |
 Posted: Wed Jul 16, 2008 11:30 am |
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I want to solder one TQFP144, but do not have
any experience with anything more than DIP40.
This is what I'm planning to do. I will:
1. apply some tinnol on all the pins on the PCB
2. remove excess tinnol with dump cloth
3. place the chip and solder it pin by pin with solder iron
step 3 will certanly solder several pins together which I plan to
fix with solder braid. The question is: what width should I buy? |
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| ian field... |
| Posted: Wed Jul 16, 2008 4:46 pm |
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"aleksa" <aleksaZR at (no spam) gmail.com> wrote in message
news:29f3968d-491c-4257-8ad8-d059f77253bd at (no spam) t54g2000hsg.googlegroups.com...
Quote: I want to solder one TQFP144, but do not have
any experience with anything more than DIP40.
This is what I'm planning to do. I will:
1. apply some tinnol on all the pins on the PCB
2. remove excess tinnol with dump cloth
3. place the chip and solder it pin by pin with solder iron
step 3 will certanly solder several pins together which I plan to
fix with solder braid. The question is: what width should I buy?
Desolder braid risks pulling up pins if you don't keep it fully and
uniformly heated.
Hold the board upside down but slanted with the ends of the pins downwards
and tease the excess solder away with the tip of the iron, you need enough
flux to prevent a skin of oxide forming. |
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| Ben Jackson... |
| Posted: Wed Jul 16, 2008 6:10 pm |
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On 2008-07-16, aleksa <aleksaZR at (no spam) gmail.com> wrote:
Quote:
1. apply some tinnol on all the pins on the PCB
2. remove excess tinnol with dump cloth
3. place the chip and solder it pin by pin with solder iron
I'm not sure what 'tinnol' is, but assuming it's some kind of liquid
flux: Skip step 2. You can readily solder fine pitch parts like that
in a puddle of flux. Fine pitch + lots of flux = easy. In fact, the
first remedy I would suggest for almost any problem (including bridged
pins) is to add flux and reheat it. You can often "pick up" the excess
solder with the iron and remove it or redistribute it. With lots of
flux, the solder will strongly prefer to stick to the pins rather than
itself which can cure the bridge.
If you get braid, make it very fine, and NEVER PULL IT OFF THE BOARD
if it resists. If you do, you will remove traces, bend pins, etc. It
can help to tin the braid as well, but it will corrode over time.
--
Ben Jackson AD7GD
<ben at (no spam) ben.com>
http://www.ben.com/ |
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| Tim Wescott... |
| Posted: Wed Jul 16, 2008 6:39 pm |
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Guest
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aleksa wrote:
Quote: I want to solder one TQFP144, but do not have
any experience with anything more than DIP40.
This is what I'm planning to do. I will:
1. apply some tinnol on all the pins on the PCB
2. remove excess tinnol with dump cloth
3. place the chip and solder it pin by pin with solder iron
step 3 will certanly solder several pins together which I plan to
fix with solder braid. The question is: what width should I buy?
Contrary to what Ian and Ben have said (and they're both good guys),
when I have to do this I use the following procedure:
1. Locate the part and tack down opposing pins (i.e. pins
1 and 73) so it sits where it belongs.
2. Solder all the pins on one side. Just drag the iron and
make a big glob of solder across all the pins. Think of
it as the Golden Gate of solder bridges.
3. Wick up the solder (carefully) with some honking big (1/8")
solder wick. Just lay it sideways on that Golden Gate of
solder and suck it all up.
It's fast, it's easy, I'm up to about a dozen parts on various boards
now, and I've never had a problem with it.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html |
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| Tony Burch... |
| Posted: Wed Jul 16, 2008 10:19 pm |
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Guest
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"aleksa" <aleksaZR at (no spam) gmail.com> wrote in message
news:29f3968d-491c-4257-8ad8-d059f77253bd at (no spam) t54g2000hsg.googlegroups.com...
Quote: I want to solder one TQFP144, but do not have
any experience with anything more than DIP40.
This is what I'm planning to do. I will:
1. apply some tinnol on all the pins on the PCB
2. remove excess tinnol with dump cloth
3. place the chip and solder it pin by pin with solder iron
step 3 will certanly solder several pins together which I plan to
fix with solder braid. The question is: what width should I buy?
Hi,
I would not recommend using solder braid. Please have a look at the video at
http://www.supersolderingsecrets.com for a reliable technique for had
soldering TQFPs.
If you don't have a "reservoir tip" for your iron, you can just use a broad
chisel tip.
Kind regards,
Anthony Burch |
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| Yukio YANO... |
| Posted: Thu Jul 17, 2008 6:57 pm |
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aleksa wrote:
Quote: I want to solder one TQFP144, but do not have
any experience with anything more than DIP40.
This is what I'm planning to do. I will:
1. apply some tinnol on all the pins on the PCB
2. remove excess tinnol with dump cloth
3. place the chip and solder it pin by pin with solder iron
step 3 will certanly solder several pins together which I plan to
fix with solder braid. The question is: what width should I buy?
I find it very very interesting that NO ONE is talking about the cursed
Lead-free solder !!! "Long-Live eutectic 65/37"
Yukio YANO |
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| Yukio YANO... |
| Posted: Thu Jul 17, 2008 7:00 pm |
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Yukio YANO wrote:
Quote: aleksa wrote:
I want to solder one TQFP144, but do not have
any experience with anything more than DIP40.
This is what I'm planning to do. I will:
1. apply some tinnol on all the pins on the PCB
2. remove excess tinnol with dump cloth
3. place the chip and solder it pin by pin with solder iron
step 3 will certanly solder several pins together which I plan to
fix with solder braid. The question is: what width should I buy?
I find it very very interesting that NO ONE is talking about the cursed
Lead-free solder !!! "Long-Live eutectic 65/37"
Yukio YANO
sorry "63/37 tin/lead" |
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