There's been a few times I see this on circuit boards. My ps2 guitar hero controller ( a cordless guitar) it was acting up lagging and shorting out. So i took it apart the power wires detached from the circuit as I moved them gently. This reddish brown stuff has eaten the copper wires. The potentiometer failed for the same reason. Scraped it all off re-soldered and BAM!! Better than new. Question. What is this stuff?
Merlin3189
- Aug 4, 2011
- 250
- Joined
- Aug 4, 2011
- Messages
- 250
I'd guess it was copper oxide, the result of corroding copper wire or PCB track.
I think it is harmless and the significant thing you are removing when you clean it off, is the electrolyte which caused the corrosion. Electrolytes conduct electricity.
I'm not sure of the chemistry behind this. Electrolytes usually come from leaking batteries. An electrolytic cell will dissolve copper at the anode, though I'd guess it would produce copper hydroxide or copper chloride, both of which are blue (and I have seen this as well as the red.) Perhaps they can further react with air to produce the oxide?
Thinking again about it another possibility is that copper metal is re-deposited at the cathode. This is often an amorphous powdery deposit which would be brownish colour.
I think it is harmless and the significant thing you are removing when you clean it off, is the electrolyte which caused the corrosion. Electrolytes conduct electricity.
I'm not sure of the chemistry behind this. Electrolytes usually come from leaking batteries. An electrolytic cell will dissolve copper at the anode, though I'd guess it would produce copper hydroxide or copper chloride, both of which are blue (and I have seen this as well as the red.) Perhaps they can further react with air to produce the oxide?
Thinking again about it another possibility is that copper metal is re-deposited at the cathode. This is often an amorphous powdery deposit which would be brownish colour.
I found this site as I was trying to figure this stuff out. Thanks got the replies. I thought of taking a photo before I started. It's too late now. I scraped it off and had to re-solder a lot of wires that connect to the board. I reassembled the cordless guitar. Calibrated it. The best it's ever been. I'm thinking it was some kind of glue. Or? The assembly plant was instructed to put that stuff on the connections knowing that it will corrode the wires in a few years. Cause most people are not like us. We fix shit if it breaks. Most would say oh well toss it in the trash and buy another one. And just maybe, the company can sell more that way
My experience with a lot of the devices coming out of China is that the assemblers are in a hurry for piece-work. They just want to get the item done and tested, and out the door.
To speed things up I've seen (maybe authorized, maybe just somebody just getting the job done), parts tacked in place so it will hold, so that the assembler can solder the wires or part in place.
Quality control is virtually non-existent in a lot of these 'get 'er done' places.
I would suspect the assembler used some sticky-stuff of some kind to hold the wires in place while they soldered the connections. The assembler was unconcerned about what might happen
later, they just wanted to quickly do what they were being paid to do. Whatever the sticky 'tack in place' stuff was , just corroded the wires over time.
No good guess on your photo. Smoke illuminated from behind maybe?
To speed things up I've seen (maybe authorized, maybe just somebody just getting the job done), parts tacked in place so it will hold, so that the assembler can solder the wires or part in place.
Quality control is virtually non-existent in a lot of these 'get 'er done' places.
I would suspect the assembler used some sticky-stuff of some kind to hold the wires in place while they soldered the connections. The assembler was unconcerned about what might happen
later, they just wanted to quickly do what they were being paid to do. Whatever the sticky 'tack in place' stuff was , just corroded the wires over time.
No good guess on your photo. Smoke illuminated from behind maybe?
Good guess. I've built and designed a few lasers and powered them up as much possible Trial and error I fried a few laser diodes. My son had lit a Roman candle and there was quite a bit of smoke so I activated the laser beam and used real fast back and forth swiping motion and the smoke contained those excited electrons which became photons long enough for me photograph it
This is what I was trying to explain. They don't become a photon they release one. I found this which explains it better. It's all Amazing to me. After I shut the laser off that green cloud just hovered and slowly disappeared. It looked like I created a temporary plasma field x
My son with the Roman candle. Or "munition". I like that word. He was at the other end of the driveway. Do steaks on the BBQ release phosphorus? I can produce a similar cloud at night from the smoke that comes from the BBQ. You guys really got me thinking on this now. The common factor is heat. The laser brings something to view out of the heat and smoke. Radiation. Infrared heat waves.
With you smart guys I better start proof reading my sentences before I hit the reply button. I probably would of caught that then I wouldn't have felt the imbarrassment of making myself look dumb. This is a photo of my son illuminating phosphorous with a laser. Totally different from the munitions smoke
- Joined
- Dec 18, 2013
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The fact you actually know what a photon and electron are makes you not dumb
how they interact can get quite complex.Adam
