I was recapping my evga nforce6200, and damaged a though hole. The thin metal lining is gone. Is there a way to repair it? Should I just junk the board? It was just a spare that had blown Sacon FZs anyway.
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Re: through hole repair??
On multi-layered boards, as in your case, it is rumored that the cap is still connected by the vias which run through the layers even if the pad is ripped from the bottom. I don't know how reliable this is though, because the way I look at it is, even if there are vias, the solder will still have to melt through the later so that the lead makes contact with the via. Most times when I ripped pads off completely on these said boards, the hole was small enough as it is, and my iron is only like 15-30 watts, so I doubt the solder was able to penetrate to the vias.
On a single-layer board, it's easy. Just scrape away some of the laminate, and run the lead to the exposed area."We have offered them (the Arabs) a sensible way for so many years. But no, they wanted to fight. Fine! We gave them technology, the latest, the kind even Vietnam didn't have. They had double superiority in tanks and aircraft, triple in artillery, and in air defense and anti-tank weapons they had absolute supremacy. And what? Once again they were beaten. Once again they scrammed [sic]. Once again they screamed for us to come save them. Sadat woke me up in the middle of the night twice over the phone, 'Save me!' He demanded to send Soviet troops, and immediately! No! We are not going to fight for them."
-Leonid Brezhnev (On the Yom Kippur War) -
Re: through hole repair??
Well I had written something, but mockingbird's explanation is much better.Originally posted by asand1 View Post--- begin sig file ---
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Re: through hole repair??
The thin metal lining inside the hole is called a via.
Repair of those is hit-miss and the outlook isn't good.
Some vias make connections to the other side of the board and that's it.
Other vias make connections between layers of the board.
You really can't tell just by looking at one.
The usual cause for problems with vias and pads is too wimpy a soldering iron or too low a temp.
The PCB material doesn't conduct much heat but with too 'cold' a tip you end up 'on the work' -longer- so the PCB material has time to absorb enough heat to melt a little and get soft releasing the pad or via.
.Last edited by PCBONEZ; 11-20-2011, 09:34 PM.Mann-Made Global Warming.
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Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
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You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
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Re: through hole repair??
I read somewhere (probably here:http://www.qsl.net/n9zia/desolder.html)
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How accurate that is I have no idea."Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
-David VanHornComment
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Re: through hole repair??
I thought the copper was electroplated on.
I'm pretty sure it is for the vias themselves.
I understand that's how they make the connections to the middle layers.
Quite possible both methods are used depending on what the board is and what they are doing.
.Mann-Made Global Warming.
- We should be more concerned about the Intellectual Climate.
-
Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
- Dr Seuss
-
You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
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Re: through hole repair??
Sorry, should have been more specific, yeah the vias and through holes would be electroplated (I don't know how you'd do it any other way)
It was just some additional information I thought was relevant to the subject of PCB damage, but should only apply to tracks\pads not the vias themselves."Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
-David VanHornComment
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Re: through hole repair??
That's not what I meant.
I thought the whole board was electroplated with copper before the etching.
You might be right and the copper is glued on or maybe they do either/or depending on the board.
Or maybe even the preferred method has changed over time.
.Mann-Made Global Warming.
- We should be more concerned about the Intellectual Climate.
-
Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
- Dr Seuss
-
You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
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Re: through hole repair??
Oh right. Yeah I wouldn't know for sure what they do now. I always thought it was glued on (that's what I always read) but that was often in books quite old."Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
-David VanHornComment
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Re: through hole repair??
As far as I know they chemically deposit the copper inside the vias,until the exact diameter of the hole is reached (the holes are drilled slightly larger on purpose)
See at about 3:45
http://www.youtube.com/watch?v=SXsch...eature=relatedComment
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Re: through hole repair??
Yeah we established that already, but what about the copper already on the board for tracks\pads etc?
Do they glue or electroplate that?"Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
-David VanHornComment
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Re: through hole repair??
And the copper layers in between PCB layers on multilayer boards.Originally posted by Agent24 View Post
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I had in my head it was electroplated on, but I really don't know.
.Mann-Made Global Warming.
- We should be more concerned about the Intellectual Climate.
-
Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.
- Dr Seuss
-
You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
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Re: through hole repair??
If it's multilayer, I'm betting glued, as they have to bond the layers with insulation between them. The video I posted shows some sort of machine where they use heat and pressure to bond them together.
I think electroplating is used just to deposit layers of gold or silver on the pads - it would take a lot of time to deposit the copper tracks at that thickness on the fiber board.
There was another Youtube video where they showed every step of pcb manufacturing with a more classical production line, with lots of vats of liquid and chemical etching and less high tech machines but I can't find it now. That explained everything in more detail...Comment
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Re: through hole repair??
Fix the board as normal and see if it operates. The power sections are usually quite simple with the front and back being ground and power so there's no need for vias to connect to internal layers.Originally posted by asand1 View Post
If a trace on either side seems to go somewhere useful then there's probably no internal connection. If neither side seems to go anywhere then there probably is an internal connection. Many caps are in parallel. As long as you didn't damage the via closest to the inductor output then adding more capacitance at an undamaged parallel location would fix the problem.
Sometimes the only purpose for the via is to connect the front to the back. If so then extra care must be taken to ensure the soldering maintains this connection.Comment
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