Hi Gents,
I'd like to use an anti-flux sometimes but I don't want to contaminate
the board or have unwanted results between opamp/IC socket pins.
If you used something that works and is safe I'd like to know
and how you use it as it would help me and maybe
some other DIYers.
Cheers,
I'd like to use an anti-flux sometimes but I don't want to contaminate
the board or have unwanted results between opamp/IC socket pins.
If you used something that works and is safe I'd like to know
and how you use it as it would help me and maybe
some other DIYers.
Cheers,
At work I have used a few flux cleaners, but none are ideal. They will all leave residue in the spots you can't get to.
If it's critical, I'll spray the board with cleaner and use compressed air to remove it from under ICs and such. That will leave streaks, though, that you might lessen a bit with a dry brush.
Note: brushing and blowing easily create ESD.
If it's critical, I'll spray the board with cleaner and use compressed air to remove it from under ICs and such. That will leave streaks, though, that you might lessen a bit with a dry brush.
Note: brushing and blowing easily create ESD.
I tried a lot of PCB cleaners and everything I tried left nasty residue which as very difficult to remove afterwards.
I always rinse PCB's under running water after cleaning and then use a hairdryer to speed up the drying process.
I use a two step process that works well for me:-
1. Break down the Flux using "Kontact" PCC cleaner (this leaves Flux residue spread evenly over the PCB like a thin sticky film).
2. The I use Electrolubes "SWA" Safewash 2000 Aqueous Foam Cleaner and using the Brush attached to the Can's "Spout" brushing in the foam on the PCB and leave for 5 minutes for the foam to "do its thing", then rinse under running water.
The PCB's are then perfectly clean with all traces of flux removed.
If you miss the first step, then the SWA Foam cleaner leaves a white residue "Halo" around each component pad... it seems the Flux needs to be broken down first before using the SWA cleaner, maybe even IPA would do in place of the Kontact PCC...
I tried many Flux cleaners, and I'm not sure if its due to the new environmental regulations, but nothing seem to work, only Electrolubes SWA...
Electrolube also offers an "After Rinse" called SRI, but I've never had problems with the PCB, it might be a different matter at 20KV, but nothing I could see visually, and I sometimes I use very high impedance designs using integrators etc.
Not sure what you can get State side...
I always rinse PCB's under running water after cleaning and then use a hairdryer to speed up the drying process.
I use a two step process that works well for me:-
1. Break down the Flux using "Kontact" PCC cleaner (this leaves Flux residue spread evenly over the PCB like a thin sticky film).
2. The I use Electrolubes "SWA" Safewash 2000 Aqueous Foam Cleaner and using the Brush attached to the Can's "Spout" brushing in the foam on the PCB and leave for 5 minutes for the foam to "do its thing", then rinse under running water.
The PCB's are then perfectly clean with all traces of flux removed.
If you miss the first step, then the SWA Foam cleaner leaves a white residue "Halo" around each component pad... it seems the Flux needs to be broken down first before using the SWA cleaner, maybe even IPA would do in place of the Kontact PCC...
I tried many Flux cleaners, and I'm not sure if its due to the new environmental regulations, but nothing seem to work, only Electrolubes SWA...
Electrolube also offers an "After Rinse" called SRI, but I've never had problems with the PCB, it might be a different matter at 20KV, but nothing I could see visually, and I sometimes I use very high impedance designs using integrators etc.
Not sure what you can get State side...
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The use of water isn't as strange as it might seem at first, as lots of pcbs used in sensitive instruments and devices needing an extremely high input impedance are washed in industrial "dish"washers using water and a detergent specificly designed for the job.
Just make sure that before you start, there are only components on the board(s) that are suitable for washing (e.g. sealed relays, no variable capacitors, buzzers with the hole still covered etc.). Whether or not a component can be washed should be in the datasheets.
Just make sure that before you start, there are only components on the board(s) that are suitable for washing (e.g. sealed relays, no variable capacitors, buzzers with the hole still covered etc.). Whether or not a component can be washed should be in the datasheets.
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Alright, I understand that.
I'm looking for an anti-flux to use before soldering so that
I can keep the solder from flowing into an area.
Looking for something that will prevent flux from
flowing to an area....like a boarder, for lack of a
better word.
I seen some jewelery anti-fluxes that prevent solder flow
to sections of a piece of jewelery when soldering.
Just looking for something similar to use for electronics.
I'm looking for an anti-flux to use before soldering so that
I can keep the solder from flowing into an area.
Looking for something that will prevent flux from
flowing to an area....like a boarder, for lack of a
better word.
I seen some jewelery anti-fluxes that prevent solder flow
to sections of a piece of jewelery when soldering.
Just looking for something similar to use for electronics.
Yep we are talking solder resist, there have been threads on this, generally it is a thinly applied epoxy based resin.... Green is best.
So if I'm working on various pitch chips,
if I try some epoxy...it's going to cause more
problems and harder/difficult/impossible to
removed during wash without destroying the
board, IC, etc.
if I try some epoxy...it's going to cause more
problems and harder/difficult/impossible to
removed during wash without destroying the
board, IC, etc.
Solder mask really needs to be put on by the board manufacturer, you can do it on home made boards but its not easy for fine pitch devices.
Kapton Tape is often used to mask areas on PCB' during solder / reflow (Gold contact Fingers etc):-
HMC Electronics Blog: Should I Use Kapton Tape or Solder Mask?
HMC Electronics Blog: Should I Use Kapton Tape or Solder Mask?
I'm not quite sure what your goals are here and why? This is a situation where the why is just as important as the what. Is it for aesthetics or is there a specific physical need. Are you wanting to prevent solder bridges and the like? In that case, the best thing in the world you can use is a good high quality flux. When the surface is properly cleaned by the flux, the solder "wets" to the surface properly and it's own surface tension and interaction with the properly cleaned surface will break up essentially ALL solder bridges. The only exception is for ultra fine pitched stuff (like BGAs), which for those situations, solder paste with a stencil is your only real option. If for some reason you want to prevent back flow of solder into particular areas and I'm not sure why but hey. You can use some sort of oxidizer to make the metal surface repulsive to solder. You could also just use solder paste. It allows a controlled addition of both solder and flux, meaning that you can control how much excess is there and as a result the amount of creepage to othre areas.
To prevent solder bridges when soldering
causing shorts or erratic electrical behavior.
Especially on the blind side after an IC socket
has be soldered into a double layer board.
causing shorts or erratic electrical behavior.
Especially on the blind side after an IC socket
has be soldered into a double layer board.
Then a good flux and a high quality solder is going to be your best bet. The flux cleans surfaces properly, and prevents solder bridging by promoting surface wetting. Anything past that, you are looking at the standard solder resist or something similar. As long as you aren't dumping huge amounts of solder into the joints then you will be just fine.
There are a variety of reasons, to not use a solder mask at times. He might have been designing an ultra low current or voltage or high impedance device. In these circuits, the leakage caused by the solder mask is not acceptable, so the use of a solder mask is not an option. These circuits though would not use a socket but I figured I would confirm.
No, Originally it didn't have a socket in it. I put one in
so that I could change opamps of different types and see
if what made improvements or didn't make improvements.
so that I could change opamps of different types and see
if what made improvements or didn't make improvements.
No, Originally it didn't have a socket in it. HP339A.
I put one in so that I could change opamps of different types and see
if what made improvements or didn't make improvements.
I had a solder bridge that I didn't detect, but it gave me problems
that I didn't know how to at the time resolve or properly diagnose.
Richard was kind enough to check it out and diagnosed and
solved the problem.
Now that I'm aware of it I know not to go back and reheat the
pins after the initial soldering. It can get tricky on dual layer
boards. Which I have limited experience working on.
So that was my original question.
Now, I'm cleaning up a ShibaSoku 725D distortion analyzer
that I got that had two problems:
1. Leaky NiCad battery on one of the boards.
2. An over night quarantine laden with DDT.
Trying to clean off the battery board with Iso OH.
That didn't work so used a solution of Ethyl OH and Baking soda.
Then H20 rinse followed by a few more Ethyl OH and Iso OH rinses.
I think I got it clean.
Then the other boards chassis, with Ethyl OH. ISO OH doesn't seem
to work as well as Ethyl OH. Also trying to remove as much of that sticky
board clean residue as JohnW described, which is on the other 9 boards.
I only use the purest Ethyl OH, the worst part is the hazardous shipping charges
for it and I can't justify a locked space for a 55gal drum. This and baking
soda are used to DECON some of the nasty chemical agents.
What I've done to two of the boards is place a kim wipe on it then
sprinkle some OH on to wet, then with a bristle brush dab and brush
which picks up the residue. I've got to do it a few times each section
to remove the sticky residue.
I'm wondering if this is the best method?
I don't have a schematic, and cannot get one, I've tried
so have many others.
On some of the boards a many chips some of which are proprietary
and if contaminated, I'm screwed. I'll never get another or the
parts to fix it with out buying another analyzer, finding a good
one is expensive.
I put one in so that I could change opamps of different types and see
if what made improvements or didn't make improvements.
I had a solder bridge that I didn't detect, but it gave me problems
that I didn't know how to at the time resolve or properly diagnose.
Richard was kind enough to check it out and diagnosed and
solved the problem.
Now that I'm aware of it I know not to go back and reheat the
pins after the initial soldering. It can get tricky on dual layer
boards. Which I have limited experience working on.
So that was my original question.
Now, I'm cleaning up a ShibaSoku 725D distortion analyzer
that I got that had two problems:
1. Leaky NiCad battery on one of the boards.
2. An over night quarantine laden with DDT.
Trying to clean off the battery board with Iso OH.
That didn't work so used a solution of Ethyl OH and Baking soda.
Then H20 rinse followed by a few more Ethyl OH and Iso OH rinses.
I think I got it clean.
Then the other boards chassis, with Ethyl OH. ISO OH doesn't seem
to work as well as Ethyl OH. Also trying to remove as much of that sticky
board clean residue as JohnW described, which is on the other 9 boards.
I only use the purest Ethyl OH, the worst part is the hazardous shipping charges
for it and I can't justify a locked space for a 55gal drum. This and baking
soda are used to DECON some of the nasty chemical agents.
What I've done to two of the boards is place a kim wipe on it then
sprinkle some OH on to wet, then with a bristle brush dab and brush
which picks up the residue. I've got to do it a few times each section
to remove the sticky residue.
I'm wondering if this is the best method?
I don't have a schematic, and cannot get one, I've tried
so have many others.
On some of the boards a many chips some of which are proprietary
and if contaminated, I'm screwed. I'll never get another or the
parts to fix it with out buying another analyzer, finding a good
one is expensive.
News to me, what leakage caused by solder resist, are we talking real world or audio here?
In fact the only boards I have done without solder mask have been for actually going into space for ESA etc.
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