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Any tips for soldering on etched boards?

Started by Guybrush, July 29, 2012, 11:59:17 AM

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Guybrush

I'm waiting for a couple of enclosures to dry so thought I'd have a go at populating a couple of etched boards I have.  I've only soldered on Madbean's fabbed boards before and not really had any problems but I'm struggling with these etched ones. 

The 1st one I tried was one that I'd etched myself.  I ruined it within 5 minutes of getting started.  I burnt a pad and lifted a trace.  After going through the etching process then drilling the pad holes I could have screamed when I screwed up the soldering.  :'(

My second effort was on a board that Haberdasher etched for me.  It is obviously of much higher quality than the one I'd made but I'm still struggling.  I've gotten a little further in but I seem to be making (I think) solder bridges.

Here's a pic of what I think is a solder bridge. 




Could someone please confirm if it is a solder bridge and let me know if it's worth carrying or should I just scrap it?


And secondly, has anyone got any tips for successfully soldering on etched boards?  Why is it so much more difficult than on a fabbed board?

Thanks guys


mgwhit

I'm not familiar with that board, but it looks like those three "bridged" pads are also connected by traces.  If that's the case, then you don't need to worry about the solder blobs touching each other.

gtr2

It helps if you lightly take something like a green scotchbrite pad and rub it over the copper traces/pads.  The copper oxidizes very quickly and it makes it difficult to solder.  Then take some rubbing alcohol 98% or acetone and clean it before soldering.

Josh
1776 EFFECTS STORE     
Contract PCB designer

jimijam

Quote from: gtr2 on July 29, 2012, 12:29:35 PM
It helps if you lightly take something like a green scotchbrite pad and rub it over the copper traces/pads.  The copper oxidizes very quickly and it makes it difficult to solder.  Then take some rubbing alcohol 98% or acetone and clean it before soldering.

Josh
agree.... by the way the solder appears to by "resisting" the traces you should clean the oxidation off the copper before soldering. if a board sits around it will oxidize pretty quickly making soldering difficult. scoth bright or very light sandpaper.600 grit or more should clean it up. or if you want to store the boards use some "tinnit" solution to plate the trace side with a thin layer of tin that resists oxidation and makes soldering easier
tried lifting weights once....they were too heavy!

slimtriggers

This won't help with soldering, I guess, but I always have the original etch image handy when I'm soldering components.  Then when I question whether I've messed up, I can refer back to that.

In this case, I agree that it looks like those are connected by traces, so you should be good.

pryde

It also helps to have a conical solder tip on your iron as direct, focused heat on the area you want solder makes the solder flow more predictible on etched boards.

They are a little different to get used to but once you get dialed in the etched boards are not so bad

Guybrush

Thanks for the replies everyone.  I'll be sure to give it a decent clean and scrub before I start soldering again.

Can I take it that if you make a solder bridge between two pads that aren't also connected by traced that the board is a write off?  I've never had much luck completely removing solder with a braid or pump.

pryde

Quote from: Guybrush on July 29, 2012, 03:10:30 PM
Thanks for the replies everyone.  I'll be sure to give it a decent clean and scrub before I start soldering again.

Can I take it that if you make a solder bridge between two pads that aren't also connected by traced that the board is a write off?  I've never had much luck completely removing solder with a braid or pump.

No you can remove as much solder as you can and then scribe a line between the pads with an exacto-blade to separate the bridge

9Lives

Quote from: pryde on July 29, 2012, 02:05:45 PM
It also helps to have a conical solder tip on your iron as direct, focused heat on the area you want solder makes the solder flow more predictible on etched boards.

They are a little different to get used to but once you get dialed in the etched boards are not so bad


+1 on the conical tip. I use the weller station with the variable temp. When I solder on my own boards I usually bump up the temp as well. I "try" to use a little solder as possible, so the when that happens I can tell if it should be connected or not. If your DMM has a continuity option on it, it never hurts to check your traces before you drill just to make sure your not wasting time. I've actually had a finished board that was grounding somewhere around the input that was invisible to the naked eye and did all the work for nothing. Check it twice do it once..  I love etched boards. Allows alot more freedom with my building. Vero is another option I use alot. Sometimes get difficult to debug but usually pretty smooth sailing if you know your layout is verified. One more thing. To me, I agree with these folks. It looks like the three pads are connected. One trick I ALWAYS use  when that happens (more often that not I forget what's supposed to be connected even after checking) is to heat up on of the solder blobs and let it sit there a second. If the solder flows into the other blob making one big blob, more than likly it's suppose to be connected. If they aren't you can usually see it try to disconnect if it doesn't actually disconnect. (comes from using small amounts of solder). It's no super secret. Just somthin I picked up on bc it happens alot. Hope that's good info for you. Conical tips the way to go dude.

9Lives

#9
o ya, meant to say this. I use a desoldering pump if all else fails just suck up the blob before you start damaging the trace/pad. When that happens you'll be so pissed. I can't stand "jerry rigging" pcbs just bothers me. So just use the pump and have a looksie. If you have trouble with the pump, just keep trying man, you'll figure it out. I'm not very good with it myself. Mine always break and the plunger won't stay in when I push it down. So I have to hold the plunger down with on hand and soldering iron in the other and just lift my thumb once it's good and melted. Somthing I also do which probably isn't  the best method is, I heat up the solder and just try to pull up the damn lead from the other side and then suck up the rest of the solder. My set of helping hands is a God-send. A Must have, if mine broke I wouldn't even attempt to try with out. I find that 9 times out of 10 (assuming your good with a soldering iron, which looked pretty good to me) if your solder bridges like that then it's supposed to be. Just be easy on the solder, use as little as possible is the key, to keep it from getting messy.

Guybrush

As always, lots of good advice.  Thank you all.

Whenever I use my solder pump (or braid for that matter) There's always a little bit of solder left on the board.  I keep trying to remove it then end up burning the pad.  In future I'll just try and cut the bridge with a craft knife as Pryde mentioned.

Good tip on heating the solder blobs 9lives.  I'll give it a try next time.  I do my best to use as little solder as possible but it still runs together.  Just need more practice I guess!

Thanks again!

9Lives

I'd put my money down that it's ok. Bc the pattern below it is the same shape. I notice people stick to similar design with their layouts. On amps and things that would be super screwed it the pad is damaged, I just cut the leads of the old component.  Then use the pump. When the lead is still in tact there a tiny bit of solder under the lead in the direction it's bent, I'm sure you noticed that's. Once you cut the leads the pump will work much better bc the piece of lead is free floating. Alot of the time it will suck it on out. (that don't sound right lol). I personally have not tried cuting the bridge before. Sounds promising. Remember this, if you lift a pad from a fabed board it's not to late. Your cab use a blade to scratch off the mask over the trace and solder directly to it. Or look at schematic and hard wire it to the previous component. It's pretty difficult to lift pads off an etched board IMO. Before I transfer I take a piece of steel wool and rough it up (just a little) just enough to give it a shiney look. If you wool it to much it makes the trace thinner leading to damaged pads and traces. Good thing about the etch board is if that happens you, you can just ben the lead to the trace and solder it on down. I'm still horrible with eagle. I'm trying to learn, but the small traces and pads are the worse culprits.

mgwhit

Don't worry about leaving a little bit of solder on the pad.  As long as it's not bridging traces or blocking the hole it shouldn't be a problem.  And on etched boards, once you've removed the component lead, the solder tends to evacuate the hole.  If it doesn't, try poking a wooden toothpick through the hole while you heat the pad.  That's more for fabbed/plate-through boards, but would work just fine for an etched board if you had that problem.  Remember, solder WANTS to flow on the heated metal trace, not the gaps.

Vallhagen

Another, maybe helpful hint:

On onesided (etched, stripboard etc)  boards i do a sharp 90 degree bend on the component leg before soldering. I want the leg flat/parallell to the board before soldering. Some kind of small tool is useful to flatten it out. Often you have to cut the leg before the solder.

On fabbed boards with feedthrough holes, everything is easier, sorta just put the component in its place and solder.

***

Hope i make myself clear... also see attached horrible paintjob...

Cheers
Bengt



Yes i still have Blüe Monster pcb-s for sale!

...and checkout: https://moodysounds.se/

9Lives

Quote from: mgwhit on July 29, 2012, 05:14:11 PM
Don't worry about leaving a little bit of solder on the pad.  As long as it's not bridging traces or blocking the hole it shouldn't be a problem.  And on etched boards, once you've removed the component lead, the solder tends to evacuate the hole.  If it doesn't, try poking a wooden toothpick through the hole while you heat the pad.  That's more for fabbed/plate-through boards, but would work just fine for an etched board if you had that problem.  Remember, solder WANTS to flow on the heated metal trace, not the gaps.
I failed to mention this too. Running the iron along the trace spreads the solder out. With the conical tips I use I usually carefully put the tip through the hole (once again, doesn't sound right) and it works well. Good point.