Can I use solder to connect a broken copper circuit?

Started by bifbangpow, March 10, 2016, 07:04:51 PM

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bifbangpow

Hey so I just etched my own circuit board and everything is perfect except there is one spot where the connection between two pads kinda fades away in the center. Theres no visible copper there. Can I just connect the two ends with a thin line of solder?

Heres a picture:

Keep on keepn on.

armdnrdy

#1
You know...it's kind of funny...solder will bridge across areas where you don't want it to...
and refuse to flow across breaks in traces when that is your goal.

Since I can't see what you're dealing with...the best thing to do.. is to solder a small gauge wire across the separation to bridge the gap.

A piece of component lead will work.

Edit:
Now that I see a picture...definitely use a wire.
You don't need to drill holes...just tack it on the trace side.
Make sure it's a good solder connection.
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

bifbangpow

Quote from: armdnrdy on March 10, 2016, 07:10:23 PM
You know...it's kind of funny...solder will bridge across areas where you don't want it to...
and refuse to flow across breaks in traces when that is your goal.

Since I can't see what you're dealing with...the best thing to do.. is to solder a small gauge wire across the separation to bridge the gap.

A piece of component lead will work.

Edit:
Now that I see a picture...definitely use a wire.

You don't need to drill holes...just tack it on the trace side.
Make sure it's a good solder connection.

Cool. That was a thought I had as well. I'll just solder component lead the to the ends of the trace.
Keep on keepn on.

blackieNYC

Make it a long piece of wire, so the whole thing doesn't move around on you. Like an inch or more.
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Cozybuilder

Whatever goes into the hole closest to the break, bend that lead over and kink it to bridge the gap, flux and solder.
Some people drink from the fountain of knowledge, others just gargle.

J0K3RX

Quote from: Cozybuilder on March 10, 2016, 07:35:02 PM
Whatever goes into the hole closest to the break, bend that lead over and kink it to bridge the gap, flux and solder.

And the winning answer goes to Cozybuilder!  ;)
Doesn't matter what you did to get it... If it sounds good, then it is good!

G. Hoffman

You can always get one of those conductive ink pens, too. 


Gabriel

PRR

My only add-on is: I would use a much-too-long scrap of wire, 6" or a foot. PCB trace and wire pre-tinned. It is easier to cut-off 5.5" of extra than to jockey short scraps.

Agree with Cozy- in this case, the part-leg at the nearest hole may be as convenient as anything. Being an over-thinker, I wonder what happens in 2036 when someone may have to replace that part and doesn't know (can't remember!) why the leg was left long. That does seem very unlikely.

Conductive ink works if you know the current is low. In pedals, that's often true. However I would have to get condy-ink shipped-in from civilization; wire-scraps I got.
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Jdansti

I like cozy's idea. I'm not sure if this is what PRR was saying, but another option would be to not immediately snip the legs of the components soldered to the two pads on each side of the missing trace and solder a small insulated jumper wire between the two legs. The jumper wire could stretch across the board "as the crow flies" and not cause any problems because it's insulated. Be sure not to block any unsoldered pads with the jumper when you do this. Snip the legs after you attach the jumper.
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R.G. Keene: EXPECT there to be errors, and defeat them...

duck_arse



in the very toppest-leftest corner, the top pad and one below it - if they are meant to be linked, they look problematic, and if they are not meant to be linked, they may well be.

[also - the outside track right next to the "S", and the same trace, bottom, bottom-right corner. both places would benefit from a bridging wire.]
don't make me draw another line.

greaser_au

#10
The "correct" way to repair it is to take a small piece of tinned copper wire (an offcut of component lead may be sufficient) at least half the width of the trace, long enough to bridge the gap plus 3.5mm (1/8") either side. Make sure it is straight, then bend it to overlay the trace (but lay flat on the board). Solder it in place (hold it in the gap with tweezers or an icecream (popsicle) stick.  This will meet most general commercial standards for a repair of this nature.  Cleaning off the flux and securing the wire across the gap in the trace with epoxy will get you to 'ordinary' MIL-STD. However, as Duck says, we have 3 more traces that need repair, and I see the track immediately to the left of the broken trace also needs some lurvin' (more than 10% reduction in width). This would be a total of 5 repairs necessary and a possible cause for rejection under reputable manufacturing house standards (more than three).

However, this is a homebrew. If I was doing this for me or someone else to use, for the outright break  I would take some thin solid wire and create a 270+ degree eyelet that loops around the 'isolated' pad, bend it to follow the path of the trace, create another eyelet at the next pad and solder it down along it's whole length. I'd treat the the two top left pads similarly. The other problem tracks would benefit from a nice 'tinning' with solder (or an offcut of resistor lead), and you'd be just fine!

david

bifbangpow

#11
Quote from: greaser_au on March 11, 2016, 09:49:04 AM
...However, as Duck says, we have 3 more traces that need repair, and I see the track immediately to the left of the broken trace also needs some lurvin' (more than 10% reduction in width). This would be a total of 5 repairs necessary and a possible cause for rejection under reputable manufacturing house standards (more than three).

However, this is a homebrew. If I was doing this for me or someone else to use, for the outright break  I would take some thin solid wire and create a 270+ degree eyelet that loops around the 'isolated' pad, bend it to follow the path of the trace, create another eyelet at the next pad and solder it down along it's whole length. I'd treat the the two top left pads similarly. The other problem tracks would benefit from a nice 'tinning' with solder (or an offcut of resistor lead), and you'd be just fine!

david

ok so I made the five corrections to the board. And I now have power at least, but still no sound. I've even resoldered every joint in the pedal three times each. No clean sound and no fx (obviously) but the led lights up.   Help help help!

Here's the new state of the board from copper side with all the repairs:



more pics:









I would greatly appreciate the help. You guys greatly improve my learning curve. And I think I've become blind to the build at this point.
Keep on keepn on.

armdnrdy

#12
You should tell us what circuit this is...
post a schematic....
and possibly a picture of the component side.

There are some very talented individuals that frequent this forum but...I am not aware of anyone here that possesses the power of telepathy.  ;)

Edit: Also...an image of the switch...since you are not passing any signal.
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

armdnrdy

when you are testing this circuit...do you have the board's trace side laying against the metal enclosure as depicted in the images?
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

bifbangpow

Quote from: armdnrdy on March 11, 2016, 04:44:51 PM
when you are testing this circuit...do you have the board's trace side laying against the metal enclosure as depicted in the images?

Yeah do you think its shorting?  should i put some tape down? Nevermind. Just tried it right side up and it still doesnt work
Keep on keepn on.

armdnrdy

It will short...many people use double sided foam tape to secure small PCBs.
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

bifbangpow

Quote from: armdnrdy on March 11, 2016, 04:37:42 PM
You should tell us what circuit this is...
post a schematic....
and possibly a picture of the component side.

There are some very talented individuals that frequent this forum but...I am not aware of anyone here that possesses the power of telepathy.  ;)

Edit: Also...an image of the switch...since you are not passing any signal.

There should be a picture of the switch up there.

its the Maestro FZ-1s from General Guitar Gadgets.
http://www.generalguitargadgets.com/effects-projects/fuzz-tones/maestro-fz-1s

and despite reading the directions in the forum, I always have trouble using my multimeter and being sure im using it correctly. Battery in or battery out etcetera.
Keep on keepn on.

armdnrdy

check the purple wire on the volume pot.

I can't see the entire picture from the picture.....

It looks like the tag end of the wire might be touching the pot body. If that's the case, it would send the output to ground.
I just designed a new fuzz circuit! It almost sounds a little different than the last fifty fuzz circuits I designed! ;)

bifbangpow

Quote from: armdnrdy on March 11, 2016, 05:18:24 PM
check the purple wire on the volume pot.

I can't see the entire picture from the picture.....

It looks like the tag end of the wire might be touching the pot body. If that's the case, it would send the output to ground.

Good to know for the future. I trimmed it. Still no sound. But at least I've learned something!
Keep on keepn on.

lars-musik

#19
Are you sure your traces are all conducting now as they should?

Maybe you should try to tin every trace with your soldering iron - that did the trick for me twice. There could be some hairline cracks somewhere.

Just heat up one joint by shorty touching it with the soldering iron tip then retrace the trace as if you would do it with a pen.

If the traces are not taking on the tin, then they are oxidised (I always use this "Lötlack" on my boards to prevent oxidation) and I have no idea how to do it then.

However, I realised that a home-etched board with one faulty trace is very often prone to fail (because it usually is not just the one faulty trace you spotted). Sometimes this still happens to me (although I etched a lot by now) and I  make it a habit to throw these boards away and etch a better one. The soldered components, the time and the nerves these boards cost are not worth it. If that feels not right for you, you should validate every single trace with your DMM before drilling an populating the board.