Solder braid: width?
Bookmark this page:
 Yahoo!
 Google
 Windows Live
 del.icio.us
 digg
 Netscape
|
|
||||||||||||||||||||||||||||||||||||||||
|
Posted by aleksa on July 16, 2008, 5:30 pm
Please log in for more thread options 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? | ||||||||||||||||||||||||||||||||||||||||
|
Posted by ian field on July 16, 2008, 5:46 pm
Please log in for more thread options 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. | ||||||||||||||||||||||||||||||||||||||||
|
Posted by Ben Jackson on July 16, 2008, 7:10 pm
Please log in for more thread options >
> 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 http://www.ben.com/ | ||||||||||||||||||||||||||||||||||||||||
|
Posted by aleksa on July 17, 2008, 12:29 pm
Please log in for more thread options >
> > > > 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 >
t
> I'm not sure what 'tinnol' is, but assuming it's some kind of liquid > flux: =A0Skip step 2. =A0You can readily solder fine pitch parts like tha= > in a puddle of flux. =A0Fine pitch + lots of flux =3D easy. =A0In fact, t=
he
> first remedy I would suggest for almost any problem (including bridged
t
> pins) is to add flux and reheat it. =A0You can often "pick up" the excess > solder with the iron and remove it or redistribute it. =A0With 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. =A0If you do, you will remove traces, bend pins, etc. =A0I= > can help to tin the braid as well, but it will corrode over time.
> > -- > Ben Jackson AD7GD 'tinnol' =3D 'solder wire'. What is liquid flux? SMD solder paste? Schukat has it, 15EUR for only 10ml of paste. Maybe it is possible to place the braid across all the pins (min 3cm), heat the whole braid and it will pick up all the solder at once? If the braid is enough heated, it won't break the traces. BTW, the minimum braid width at Schukat is 0.5mm, max 2mm. | ||||||||||||||||||||||||||||||||||||||||
|
Posted by Tim Wescott on July 16, 2008, 7:39 pm
Please log in for more thread options 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? 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 | ||||||||||||||||||||||||||||||||||||||||
| Similar Threads | Posted |
| Solder braid: width? | July 16, 2008, 5:30 pm |
| Sodler braid | November 28, 2006, 5:59 pm |
| Silver Solder, Lead Free Solder . . . . | February 11, 2006, 7:04 am |
| low width and pincushion | March 14, 2006, 6:30 pm |
| Delay without affecting pulse width | March 7, 2005, 3:15 pm |
| How to generate a narrow pulse it width 500 - 700 picosecond? | January 6, 2006, 9:39 pm |
| pulse width modulation spectrum analysis | August 20, 2007, 6:33 am |
| Phase lock loop 4046 ( band width) | August 15, 2005, 6:55 am |
| Using a solder pot | July 9, 2007, 3:29 pm |
| Solder pump | January 1, 2005, 2:38 am |
| DIY Solder mask? | February 16, 2005, 1:07 pm |
| Solder Training | March 19, 2006, 9:57 pm |
| What kind of Solder for SMD please !!!! | April 11, 2006, 9:51 am |
| What is the use of FLUX when we solder? | August 22, 2006, 1:51 pm |
| Re: Splattering solder into eye? | October 25, 2008, 2:57 pm |
> 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?