When I applied thermal paste to my mica pads to put under some TO-3 devices, some squeezed through the PCB onto the solder pad.
Right now, solder is just beading on top of the pad.
I tried cleaning with alcohol, but it didn't work.
What is a PCB safe cleaner I can use to clean the thermal paste off the solder pad?
(C23 is a cap on the back, but it is the leads from the TO-3 device on the top passing through the PCB)
Thank you,
David.
Right now, solder is just beading on top of the pad.
I tried cleaning with alcohol, but it didn't work.
What is a PCB safe cleaner I can use to clean the thermal paste off the solder pad?
(C23 is a cap on the back, but it is the leads from the TO-3 device on the top passing through the PCB)
Thank you,
David.
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It should be 99%. The cheap stuff from the dollar store won't work.
You can also use Methyl hydrate. I use the latter to clean Arctic Silver off of CPU dies.
You can also use Methyl hydrate. I use the latter to clean Arctic Silver off of CPU dies.
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Get a can of compressed air, shake it for about a minute, turn it upside down and spray the liquid gas sideways over the pad. This will freeze and blow away everything thats not ment to be there - especially silicons and grease. Be carefull: Only do this with air circulation and without any heatsource around you (solder iron, ...).
Alternatively get a glasfiberpen and scratch of some of the soldermask next to the contamined pad and use the fresh copper-area to solder the component with a solderbulb.
Alternatively get a glasfiberpen and scratch of some of the soldermask next to the contamined pad and use the fresh copper-area to solder the component with a solderbulb.
Try #0000 steel wool to scrub first, then lighter fluid (clean mineral spirits), then dry off and then methyl alcohol. Dry with clean cotton swab or cloth. Use a high quality liquid flux meant for SMT soldering. Fumes released are noxious so don’t breathwhen soldering but it will cut through most things for a good joint. Kester 951 works great.
But if your joint is near a heatsinked part, or a ground plane that lacks thermal reliefs (as is the case here), there could be too much cooling and the pad never gets hot enough to fully wet with molten solder. You might try preheating with hot air gun to get area up to at least 125C. Then your iron should be able to melt the solder easily and wet parts. Or get a really big high wattage soldering iron.
If your part has a pin sticking through the pad and there’s no room to mechanically scrub, the methanol and liquid flux should do it. But I think problem is your iron is not powerful enough and you are not using the biggest chisel tip for max thermal transfer.
But if your joint is near a heatsinked part, or a ground plane that lacks thermal reliefs (as is the case here), there could be too much cooling and the pad never gets hot enough to fully wet with molten solder. You might try preheating with hot air gun to get area up to at least 125C. Then your iron should be able to melt the solder easily and wet parts. Or get a really big high wattage soldering iron.
If your part has a pin sticking through the pad and there’s no room to mechanically scrub, the methanol and liquid flux should do it. But I think problem is your iron is not powerful enough and you are not using the biggest chisel tip for max thermal transfer.
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agree with "X", you are trying to solder a ground plane, it takes a lot of heat. I turn my Weller up to 400-450 degrees celcius to solder those types of situations.
You are not really making an effort 😉 , I still see a ton of white residue there, both on solder pad and solder mask around it, that area is DIRTY.
It will not "dissolve", you must mechanically clean the area, wipe/brush white grease away.
Wet the area with solvent (ethyl/methyl/isopropyl alcohol, lighter fluid, acetone, even kerosene) , push grease away with a toothpick and wipe remains with a paper towel, repeat twice just in case, area must be squeaky clean.
And yes, you may be using a too small soldering iron.
40W minimum, 60W even better.
And with a conical/chisel/pyramid tip; a thin needle one is good for ICs and SMT stuff, but not there.
It will not "dissolve", you must mechanically clean the area, wipe/brush white grease away.
Wet the area with solvent (ethyl/methyl/isopropyl alcohol, lighter fluid, acetone, even kerosene) , push grease away with a toothpick and wipe remains with a paper towel, repeat twice just in case, area must be squeaky clean.
And yes, you may be using a too small soldering iron.
40W minimum, 60W even better.
And with a conical/chisel/pyramid tip; a thin needle one is good for ICs and SMT stuff, but not there.