How to fill in VIA?

[cfox10]

Hello,


I'm currently repairing a damaged amplifier board and was trying to figure out the best method for filling the VIA from where the MOSFET came off of.

Any help would be appreciated.. I've searched and searched.. pictures would be great as well if anyone has any examples.

[stj]

Re: How to fill in VIA?

you mean you ripped out the through-hole plating?

[cfox10]

Re: How to fill in VIA?

you mean you ripped out the through-hole plating?

This amp has been worked on previously before I got it. Appears it will need them filled/fixed.

[Agent24]

Re: How to fill in VIA?

Assuming it's just a double-sided board, then it's easy.

For the two outer legs, the top side pad doesn't go anywhere, so ignore it. For the center leg, if the pad is ripped, scrape some of the soldermask off with a sharp blade (I find a scalpel works very well) next to it on the land and make a solder bridge from the lead to the freshly exposed copper. You can also add a piece of wire to help.

For the bottom side the same applies. If the center lead has connections on both sides of the board you will need to reconnect on both sides. For the outer two legs it seems they only connect on the bottom.

To clear any blocked holes, I would fill them with fresh solder, then holding the board sideways, hold a desolder pump on one side and your iron on the other side of the filled hole. Heat the solder until liquid and then wait a couple seconds more, hit the desolder pump button as you remove the iron, the hole should be cleared easily.

Use the iron on whichever side of the hole has the largest track\plane to heat it more effectively.

[cfox10]

Re: How to fill in VIA?

Assuming it's just a double-sided board, then it's easy.

For the two outer legs, the top side pad doesn't go anywhere, so ignore it. For the center leg, if the pad is ripped, scrape some of the soldermask off with a sharp blade (I find a scalpel works very well) next to it on the land and make a solder bridge from the lead to the freshly exposed copper. You can also add a piece of wire to help.

For the bottom side the same applies. If the center lead has connections on both sides of the board you will need to reconnect on both sides. For the outer two legs it seems they only connect on the bottom.

To clear any blocked holes, I would fill them with fresh solder, then holding the board sideways, hold a desolder pump on one side and your iron on the other side of the filled hole. Heat the solder until liquid and then wait a couple seconds more, hit the desolder pump button as you remove the iron, the hole should be cleared easily.

Use the iron on whichever side of the hole has the largest track\plane to heat it more effectively.

I found this method. Sounds kind of like what you're stating.. scrape back some copper from the trace and solder a wire to it/fill the hole with the wire.

I'm going to for the easiest/cleanest looking method I can. Don't want it looking odd as it's covered by plexiglass showing off the internals of the amp lol

[Agent24]

Re: How to fill in VIA?

Don't use the exact method in that photo then. Besides looking horrible, that wire is quite thin compared to the original pad and may cause some kind of performance issues or such.

I was thinking of a much shorter, and thicker piece of wire, just enough to go between the transistor leg and the land\track immediately next to it.

I'll try to find or take a photo that shows my idea better.

[cfox10]

Re: How to fill in VIA?

Don't use the exact method in that photo then. Besides looking horrible, that wire is quite thin compared to the original pad and may cause some kind of performance issues or such.

I was thinking of a much shorter, and thicker piece of wire, just enough to go between the transistor leg and the land\track immediately next to it.

I'll try to find or take a photo that shows my idea better.

If you could find or take a photo that would be great. I've never actually ran into this issue before, wish it was something I was taught. We had this conductive epoxy stuff that we used to fill the holes with.. I can't find it anywhere, and I'm not sure it'd work in this case anyway.