Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

How to avoid a carbon formation on PCB?

Status
Not open for further replies.

gravi

Full Member level 2
Joined
May 30, 2006
Messages
126
Helped
10
Reputation
20
Reaction score
10
Trophy points
1,298
Location
Hyderabad, India
Activity points
2,424
Hi,
We have designed an PCB and tested it's performance in lab and tested in field for about 2 years and found Every functionality OK but we have observed some kind of dust black in colour looks like carbon is formed on PCB will this affect the performance of the PCB in long run. Can Anyone suggest me to avoid this carbon formation on PCB.


With Regard's,
Ravi Kumar
 

sabeti_1990

Full Member level 4
Joined
Nov 16, 2007
Messages
195
Helped
23
Reputation
46
Reaction score
12
Trophy points
1,298
Activity points
2,216
Re: Carbon on PCB

hi
if be possible give a picture from it
have your pcb a silk screen on the top of board ?
it may be because of your soldering wire
 

ASIC

Full Member level 3
Joined
May 18, 2001
Messages
164
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,298
Activity points
1,205
Carbon on PCB

where would this "carbon" come from?
 

pranam77

Advanced Member level 5
Joined
Apr 22, 2008
Messages
2,786
Helped
553
Reputation
1,104
Reaction score
371
Trophy points
1,363
Location
INDIA
Activity points
16,415
Re: Carbon on PCB

Carbon formation on PCB is not possible. It may be a copper layer oxidized appearing like black spots. If a photo is given will try to guess more about that.
 

tanuki

Member level 5
Joined
Jun 11, 2001
Messages
92
Helped
4
Reputation
8
Reaction score
1
Trophy points
1,288
Location
Spain
Activity points
841
Re: Carbon on PCB

Copper is oxidized to a black finish to improve laminate adhesion.

If it's copper oxide, dilute sulfuric acid will dissolve the particles, making the resulting solution blue ( or blue tinted, if there are enough particles.).

If it's carbon, even concentrated sulfuric acid will not dissolve it. However it can be burned rather easily, where as any metal oxides will be unaffected but high temperatures.

More info: https://www.wipo.int/pctdb/en/wo.jsp?IA=GB1995002909&DISPLAY=DESC
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top