Homebrew PCBs

Last week you all may remember me having a ton of problems getting 
toner to stick to some PCB material.  Alan suggested that I pre-etch 
the board to see if that would help.  It was tried and seem to improve 
the adhesion on the smaller test samples, but not on the larger 
boards.  

I am wondering if any of you chemically smart folks here can shed some 
light on what would happen to silicone when imersed int he ferric 
chloride?  

This new board material is rather shiny, more so than the previous 
material I have bought in the past.  So I suspect that there is some 
sort of coating on the boards that is causing me these problems.

Thanks for the input!

Chris

On Mon, 07 Nov 2005 22:29:54 +0100, lcdpublishing  
<lcdpublishing@...> wrote:

> Last week you all may remember me having a ton of problems getting
> toner to stick to some PCB material.  Alan suggested that I pre-etch
> the board to see if that would help.  It was tried and seem to improve
> the adhesion on the smaller test samples, but not on the larger
> boards.
> I am wondering if any of you chemically smart folks here can shed some
> light on what would happen to silicone when imersed int he ferric
> chloride?
> This new board material is rather shiny, more so than the previous
> material I have bought in the past.  So I suspect that there is some
> sort of coating on the boards that is causing me these problems.
> Thanks for the input!
> Chris


I'm not chemically smart, but silicone sealant is not attaacked by CuCl. I  
dunno about silicone oil/grease but i do no think it is cleaned off.

Make sure first it is really the material. Get some old stock and make  
100% identical test. I do suspect it might be something else.

ST

Okay, will do some side-by-side comparitive tests.  I don't have 
much left of the material I was using, but hopefully there is enough 
here that is big enough to do some good comparisons.

Thanks!
Chris




--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> On Mon, 07 Nov 2005 22:29:54 +0100, lcdpublishing  
> <lcdpublishing@y...> wrote:
> 
> > Last week you all may remember me having a ton of problems 
getting
> > toner to stick to some PCB material.  Alan suggested that I pre-
etch
> > the board to see if that would help.  It was tried and seem to 
improve
> > the adhesion on the smaller test samples, but not on the larger
> > boards.
> > I am wondering if any of you chemically smart folks here can 
shed some
> > light on what would happen to silicone when imersed int he ferric
> > chloride?
> > This new board material is rather shiny, more so than the 
previous
> > material I have bought in the past.  So I suspect that there is 
some
> > sort of coating on the boards that is causing me these problems.
> > Thanks for the input!
> > Chris
> 
> 
> I'm not chemically smart, but silicone sealant is not attaacked by 
CuCl. I  
> dunno about silicone oil/grease but i do no think it is cleaned 
off.
> 
> Make sure first it is really the material. Get some old stock and 
make  

> 100% identical test. I do suspect it might be something else.
> 
> ST
>

Theoreticaly, silicone sealant is chemically inert. So should no 
interact whith no other chemical element. This is the reason for 
silicone usings in  medicine.
This is also the reason for bad things. Silicone grease is verry hard 
to remouve. If an object is contaminated whith this grease...bad news. 
Is allmost imposible to paint it, glue it, or etch it.






Adrian 



--- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing" 
<lcdpublishing@y...> wrote:
>
> Last week you all may remember me having a ton of problems getting 
> toner to stick to some PCB material.  Alan suggested that I pre-etch 
> the board to see if that would help.  It was tried and seem to 
improve 
> the adhesion on the smaller test samples, but not on the larger 
> boards.  
> 
> I am wondering if any of you chemically smart folks here can shed 
some 

> light on what would happen to silicone when imersed int he ferric 
> chloride?  
> 
> This new board material is rather shiny, more so than the previous 
> material I have bought in the past.  So I suspect that there is some 
> sort of coating on the boards that is causing me these problems.
> 
> Thanks for the input!
> 
> Chris
>

Hi Adrian,

Thanks for the info. The boards do etch fine, I just can't get toner 
to stick to them.  However, I am sure there is something on the boards 
making them stay shiny and also there is a good chance they use 
something in the mfg process to lubricate the rollers and such while 
forming the copper.  However, I would think if they used silicone 
during the copper mfg. process, they would have trouble bonding the 
copper to the epoxy-glass boards.

WIll report back any further findings...
Thanks again!

Chris



--- In Homebrew_PCBs@yahoogroups.com, "adicont2" <adicont2@y...> wrote:
>
> Theoreticaly, silicone sealant is chemically inert. So should no 
> interact whith no other chemical element. This is the reason for 
> silicone usings in  medicine.
> This is also the reason for bad things. Silicone grease is verry 
hard 
> to remouve. If an object is contaminated whith this grease...bad 
news. 

> Is allmost imposible to paint it, glue it, or etch it.
> 
> 
> 
> 
> 
> 
> Adrian 
>

On Mon, 07 Nov 2005 23:51:25 +0100, lcdpublishing  
<lcdpublishing@...> wrote:

> Hi Adrian,
> Thanks for the info. The boards do etch fine, I just can't get toner
> to stick to them.  However, I am sure there is something on the boards
> making them stay shiny and also there is a good chance they use
> something in the mfg process to lubricate the rollers and such while
> forming the copper.  However, I would think if they used silicone
> during the copper mfg. process, they would have trouble bonding the
> copper to the epoxy-glass boards.
> WIll report back any further findings...
> Thanks again!
> Chris


Chris,

it makes no sense to coat the PCBs with something that prevents coating  
with resist, intentionally or by accident.
The manufacturer could not sell the material so he can not produce it.
If it was coated with some "mystery material" it must have been by  
accident later on, or maybe a silly person "preventing corrosion".

In PCB houses the boards are cleaned by motorised scrubbers and water  
only, usually, i'm told.

ST

On Mon, 07 Nov 2005 22:59:28 +0100, adicont2 <adicont2@...> wrote:

> Theoreticaly, silicone sealant is chemically inert. So should no
> interact whith no other chemical element. This is the reason for
> silicone usings in  medicine.
> This is also the reason for bad things. Silicone grease is verry hard
> to remouve. If an object is contaminated whith this grease...bad news.
> Is allmost imposible to paint it, glue it, or etch it.
> Adrian


It can not be solved by solvents like acetone?


ST

I don't think so, but not sure. Like someone mentioned last week, 
autobody shops have a horrible time dealing with "Fish eyes" in the 
paint.  This is caused by silicone "waxes" people apply to their 
cars to keep them shiny and new looking.  I know that laquer thinner 
doesn't seem to remove it good enough to prevent problems. Don't 
know about acetone though, never seen the body shops use acetone.  
However, I scrubbed the boards good with acetone prior to 
transfering the toner.  

Gosh this is frustrating.  What was working so perfectly now works 
horridly.  I hope to get some time to focus on this and get to the 
bottom of it in the coming weeks.  

Also, for what it is worth, I tried many different ink jet papers 
(glossy stuff), pages from magazines, toner transfer paper, and the 
pulsar transfer paper, and something else of which I can't remember 
now.  All yielded nearly identical problems, in other words, none of 
them performed better than the other - so now I know I don't have to 
buy the expensive papers anymore - just use the glossy papers :-)

CHris



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
>
> On Mon, 07 Nov 2005 22:59:28 +0100, adicont2 <adicont2@y...> wrote:
> 
> > Theoreticaly, silicone sealant is chemically inert. So should no
> > interact whith no other chemical element. This is the reason for
> > silicone usings in  medicine.
> > This is also the reason for bad things. Silicone grease is verry 
hard
> > to remouve. If an object is contaminated whith this grease...bad 
news.

> > Is allmost imposible to paint it, glue it, or etch it.
> > Adrian
> 
> 
> It can not be solved by solvents like acetone?
> 
> 
> ST
>

Stefan,

By chance do you happen to know what process the board MFGs use to 
remove the excess copper? (as in etching boards the way we do to leave 
only the traces)

 I am guessing it is a chemical etching of some sort, but have no idea 
beyond a guess.

Chris


 
> it makes no sense to coat the PCBs with something that prevents 
coating  
> with resist, intentionally or by accident.
> The manufacturer could not sell the material so he can not produce 
it.
> If it was coated with some "mystery material" it must have been by  
> accident later on, or maybe a silly person "preventing corrosion".
> 
> In PCB houses the boards are cleaned by motorised scrubbers and 
water  

> only, usually, i'm told.
> 
> ST
>

On Tue, 08 Nov 2005 00:12:41 +0100, lcdpublishing  
<lcdpublishing@...> wrote:

> Stefan,
> By chance do you happen to know what process the board MFGs use to
> remove the excess copper? (as in etching boards the way we do to leave
> only the traces)
> I am guessing it is a chemical etching of some sort, but have no idea
> beyond a guess.
> Chris


usually chemical etching. as far as i know mostly sulphuric etchants and  
some CuCl, conveyor spraying any maybe bubble tanks in smaller operations  
i think.

Most seem to use laminated film resists (as those are tenting THP), or  
"inverted" resist and tin plating with sulphuric etchants.

That's what i gathered seems common, not 100% sure. Never seen a  
industrial etching shop inside, actually. There are sure ppl here that  
have seen some.

ST

In my knowledge there is no solvent for silicone. Don't ask me how the 
manufacturers of silicone products deal whith this problem.
All this products, is made by mixing some aditives and silicone. 
Imagine this mysterious silicone like microscopic balls, mixed in some 
oil or grease. When you try to remove it, you use acetone. The acetone 
wash aditives but not the balls. Some balls, because there is no 
aditive to stick them in place, will be removed. Never all.

Your problem is allmost sure not a silicone problem, because you can 
etch the PCB. Is a realy weird problem. Maybe is related to copper 
quality like thermal or electrostatic proprieties.



Adrian


--- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing" 
<lcdpublishing@y...> wrote:
>
> I don't think so, but not sure. Like someone mentioned last week, 
> autobody shops have a horrible time dealing with "Fish eyes" in the 
> paint.  This is caused by silicone "waxes" people apply to their 
> cars to keep them shiny and new looking.  I know that laquer thinner 
> doesn't seem to remove it good enough to prevent problems. Don't 
> know about acetone though, never seen the body shops use acetone.  
> However, I scrubbed the boards good with acetone prior to 
> transfering the toner.  
> 
> Gosh this is frustrating.  What was working so perfectly now works 
> horridly.  I hope to get some time to focus on this and get to the 
> bottom of it in the coming weeks.  
> 
> Also, for what it is worth, I tried many different ink jet papers 
> (glossy stuff), pages from magazines, toner transfer paper, and the 
> pulsar transfer paper, and something else of which I can't remember 
> now.  All yielded nearly identical problems, in other words, none of 
> them performed better than the other - so now I know I don't have to 
> buy the expensive papers anymore - just use the glossy papers :-)
> 
> CHris
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
> <stefan_trethan@g...> wrote:
> >
> > On Mon, 07 Nov 2005 22:59:28 +0100, adicont2 <adicont2@y...> 
wrote:

> > 
> > > Theoreticaly, silicone sealant is chemically inert. So should no
> > > interact whith no other chemical element. This is the reason for
> > > silicone usings in  medicine.
> > > This is also the reason for bad things. Silicone grease is verry 
> hard
> > > to remouve. If an object is contaminated whith this grease...bad 
> news.
> > > Is allmost imposible to paint it, glue it, or etch it.
> > > Adrian
> > 
> > 
> > It can not be solved by solvents like acetone?
> > 
> > 
> > ST
> >
>

Some potentially related info:

 http://www.eng-tips.com/viewthread.cfm?qid=28166

The best advice here IMO is to Ask the mfr.! 

Funny how seldom we do that...

Hope this helps,

Ballendo

--- In Homebrew_PCBs@yahoogroups.com, "adicont2" <adicont2@y...> 
wrote:
>
> In my knowledge there is no solvent for silicone. Don't ask me how 
the 
> manufacturers of silicone products deal whith this problem.
<snip>

In a message dated 11/7/2005 3:31:57 P.M. Central Standard Time,  
lcdpublishing@... writes:

So I  suspect that there is some 
sort of coating on the boards that is causing  me these problems.



Chris!
 
If so (I'd have NO clue!), then scrub off all the "shiny" with  grey 
Scotchbrite, using liquid soap (like one uses for dishes!) and hot  water.  RINSE 
super-well with clean water, dry, and try that.  


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

In a message dated 11/7/2005 5:05:06 P.M. Central Standard Time,  
stefan_trethan@... writes:

It can  not be solved by solvents like acetone?


no


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

In a message dated 11/7/2005 5:10:13 P.M. Central Standard Time,  
stefan_trethan@... writes:

it makes  no sense to coat the PCBs with something that prevents coating with 
 resist, intentionally or by accident.  The manufacturer could not sell  the 
material so he can not produce it.  If it was coated with some  "mystery 
material" it must have been by accident later on, or maybe a  silly person 
"preventing corrosion".<<
ST!  SURE it makes sense!  An "invisible" goop that  keeps the fresh copper 
bright is a "sales tool", of course!  The USERS must  realize this must be 
scrubbed off before resist-application!





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

On Tue, 08 Nov 2005 06:23:49 +0100, <JanRwl@...> wrote:

>
> it makes  no sense to coat the PCBs with something that prevents coating  
> with
>  resist, intentionally or by accident.  The manufacturer could not sell   
> the
> material so he can not produce it.  If it was coated with some  "mystery
> material" it must have been by accident later on, or maybe a  silly  
> person
> "preventing corrosion".<<


> ST!  SURE it makes sense!  An "invisible" goop that  keeps the fresh  
> copper
> bright is a "sales tool", of course!  The USERS must  realize this must  
> be
> scrubbed off before resist-application!



But surely, if they put some protection on (and they seem to do on my
boards) it must be something that is easily cleaned off, NOT silicone
grease!

ST

In a message dated 11/8/2005 4:02:27 A.M. Central Standard Time,  
stefan_trethan@... writes:

surely,  if they put some protection on (and they seem to do on my
boards) it must  be something that is easily cleaned off, NOT  silicone
grease!



I agree with you, there!


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