Homebrew PCBs

Hi everybody,

removing toner from a PCB after etching leaves toner impregnating the
epoxy, giving "black clouds" on it.

Does anyone of you get the same ?

Has anyone already solved the problem ?

Mike.

On Wed, 31 Oct 2007 16:43:25 -0000, you wrote:

>Hi everybody,
>
>removing toner from a PCB after etching leaves toner impregnating the
>epoxy, giving "black clouds" on it.

It can.
>
>Does anyone of you get the same ?
>

Not all that much

>Has anyone already solved the problem ?

I clean the boards with acetone, which seems to remove it.  Of course,
I also have some black PC material, which renders the question moot.

Harvey

>
>Mike.

Don't use acetone to remove the toner, instead use a steel scraper or
even the edge of another PCB to scrape the toner off mechanically.
Then use acetone to remove any tiny bits that may be left and to clean
the board.

No the scraping will not damage thin traces if you don't scrape with a corner.

Some PCBs seem to be more prone to this clouding thing than others. I
believe they are not all the same epoxy, or maybe some aren't epoxy at
all.

ST

On 10/31/07, bagmik <bagmik@...> wrote:
> Hi everybody,
>
> removing toner from a PCB after etching leaves toner impregnating the
> epoxy, giving "black clouds" on it.
>
> Does anyone of you get the same ?
>
> Has anyone already solved the problem ?
>
> Mike.
>
>

I have noticed this happens when there is less Acetone and what I do is either have a dripping tissue paper with acetone when I rub it off so the board does not dry out till all the black is gone or dip it in acetone and brush it off under acetone.
  This clouding happens only on some boards and there is no way of removing it once it is clouded, so I think there is some reaction going on between the board, toner and acetone as acetone evaporates.
   
  Kim
  

bagmik <bagmik@...> wrote:
  Hi everybody,

removing toner from a PCB after etching leaves toner impregnating the
epoxy, giving "black clouds" on it.

Does anyone of you get the same ?

Has anyone already solved the problem ?

Mike.



Be sure to visit the group home and check for new Links, Files, and Photos:
http://groups.yahoo.com/group/Homebrew_PCBs 
Yahoo! Groups Links






[Non-text portions of this message have been removed]

Thank to all for your answers.
It seems that it doesn't happen with all kind of epoxy, could be dependant of the manufacturing process.
I'll frist try Kim's solution, brushing the toner off under acetone and post the results.

Thank again.

Mike.
 
 __________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

[Non-text portions of this message have been removed]

I'm with Stefan.  After etching, I clean off the toner in running
water, using gentle pressure from a stainless steel pot-scrubber pad,
the same one I use for cleaning the copper beforehand.

It's fast, works fine, and, despite what you might fear, it doesn't
damage the 8-10 mil traces I usually use.  No chemicals, no mess.

James Arthur

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@...> wrote:
>
> Don't use acetone to remove the toner, instead use a steel scraper or
> even the edge of another PCB to scrape the toner off mechanically.
> Then use acetone to remove any tiny bits that may be left and to clean
> the board.
> 
> No the scraping will not damage thin traces if you don't scrape with
a corner.

> 
> Some PCBs seem to be more prone to this clouding thing than others. I
> believe they are not all the same epoxy, or maybe some aren't epoxy at
> all.
> 
> ST
> 
> On 10/31/07, bagmik <bagmik@...> wrote:
> > Hi everybody,
> >
> > removing toner from a PCB after etching leaves toner impregnating the
> > epoxy, giving "black clouds" on it.
> >
> > Does anyone of you get the same ?
> >
> > Has anyone already solved the problem ?
> >
> > Mike.

Acetone is a solvent that actually coftens the resin
used to make PCBs. Soaking the board is not a good
idea. I just rub mine with a paper towel moisend with
acetone.

Bob Macklin
Seattle, Wa.

--- Kim Vellore <kimvellore@...> wrote:

> I have noticed this happens when there is less
> Acetone and what I do is either have a dripping
> tissue paper with acetone when I rub it off so the
> board does not dry out till all the black is gone or
> dip it in acetone and brush it off under acetone.
>   This clouding happens only on some boards and
> there is no way of removing it once it is clouded,
> so I think there is some reaction going on between
> the board, toner and acetone as acetone evaporates.
>    
>   Kim
>   
> 
> bagmik <bagmik@...> wrote:
>   Hi everybody,
> 
> removing toner from a PCB after etching leaves toner
> impregnating the
> epoxy, giving "black clouds" on it.
> 
> Does anyone of you get the same ?
> 
> Has anyone already solved the problem ?
> 
> Mike.
> 
> 
> 
> Be sure to visit the group home and check for new
> Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs 
> Yahoo! Groups Links
> 
> 
> 
> 
> 
> 
> [Non-text portions of this message have been
> removed]
> 
> 
> 
> Be sure to visit the group home and check for new
> Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs 
> Yahoo! Groups Links
> 
> 
> mailto:Homebrew_PCBs-fullfeatured@yahoogroups.com
> 
> 
>

Hi everybody,

Looking to solve this problem, I found in my garage on a shelf an old bottle of synthetic thinner for paint, toluene based (don't know if it can still be sold) that did the work great.
I've been able to remove the toner clouds with it on already etched PCB.
Some of them which were too deep in the epoxy were not removed completly but turned to a light gray.
This thinner is a little bit greasy so cleaning with acetone is needed.

btw, I finally got good results with TT, 8 mils track width and 6 mils spacing.


Michel Baguet <bagmik@...> wrote:                               Thank to all for your answers.
 It seems that it doesn't happen with all kind of epoxy, could be dependant of the manufacturing process.
 I'll frist try Kim's solution, brushing the toner off under acetone and post the results.
 
 Thank again.
 
 Mike.
  
  __________________________________________________
 Do You Yahoo!?
 Tired of spam?  Yahoo! Mail has the best spam protection around 
 http://mail.yahoo.com 
 
 [Non-text portions of this message have been removed]
 
 
     
                               

 __________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

[Non-text portions of this message have been removed]

Yes, and acetone is cheap.
But i am cheaper and that would use way too much of it for my liking.
I think it depends a lot on the toner how well it flakes off with
mechanical scraping.
Mine comes off very easily so i prefer that.

ST

On 10/31/07, Kim Vellore <kimvellore@...> wrote:
> I have noticed this happens when there is less Acetone and what I do is either have a dripping tissue paper with acetone when I rub it off so the board does not dry out till all the black is gone or dip it in acetone and brush it off under acetone.
>  This clouding happens only on some boards and there is no way of removing it once it is clouded, so I think there is some reaction going on between the board, toner and acetone as acetone evaporates.
>
>  Kim