Homebrew PCBs

Today I needed a board.... NOW...... so I made one.
Wish I had through hole plating, but that would only have added some
more time, I hand wired the via's by riveting soft copper wire into the
16 mil holes.

SMD C's and R's are 0805

Transparencies exposed in my workshop normal room lighting, printed
using HP laserjet 1100, in the ground plane area I can see light through
it, it look grey when held up to room light. Notice the ground plans are
clean and show not problem with what many would say was not dark enough.

http://hans-w.com/before_touchup.jpg  Shows a scrap of double sided
board I had, who knows how old it is ! Exposure

http://hans-w.com/before_drilling.jpg  just to give an idea of how
cleanly it came out of the etch.

http://hans-w.com/before_riveted_vias.jpg  drilled using drill press and
Dremel drill, ready for wire via's

http://hans-w.com/board_riveted_vias.jpg wires in place and riveted,
before soldering not nice but it's stable.

http://hans-w.com/board_assembled.jpg all SMD parts added and cleaned.

OK so this only has everyday 0805 and 10 mil traces  nothing super
small. Notice where possible I make via pads as big, I like to make it
easy for myself.

So... the edges may not be razor sharp, but I'm fairly sure the
electrons are not going to complain about that, I think they like the
silver plating...( I used CoolAmp)

The point is, making everyday boards does not require rocket science,
special printers and all that. Just get to know you Light source,
distance and
the Lye developer and you can made boards like this all day long.

Could I have done it with an inkjet printer, well I'm sure I could, but
the LJ prints the artwork in 20 seconds, none of my three InkJet and do
that !

If anyone has a problem with this kind of board lets hears some sensible
arguments, tell me why it's not going to work, and explain the reason
please...

As far as I'm concerned the issue that  Laser Jet's are not good, is now
put to rest once and for all.
I suspect the people that tried LJ's may have had poor results because
of bad media, or toner cartridge may have been low, or both.

Have a good fourth...

Hans W

Hans Wedemeyer wrote:
> Today I needed a board.... NOW...... so I made one.
> Wish I had through hole plating, but that would only have added some
> more time, I hand wired the via's by riveting soft copper wire into the
> 16 mil holes.
> 
> SMD C's and R's are 0805
> 
> Transparencies exposed in my workshop normal room lighting, printed
> using HP laserjet 1100, in the ground plane area I can see light through
> it, it look grey when held up to room light. Notice the ground plans are
> clean and show not problem with what many would say was not dark enough.
> 
...
> 
> OK so this only has everyday 0805 and 10 mil traces  nothing super
> small. Notice where possible I make via pads as big, I like to make it
> easy for myself.
> 
> So... the edges may not be razor sharp, but I'm fairly sure the
> electrons are not going to complain about that, I think they like the
> silver plating...( I used CoolAmp)
> 
> The point is, making everyday boards does not require rocket science,
> special printers and all that. Just get to know you Light source,
> distance and
> the Lye developer and you can made boards like this all day long.
> 
> Could I have done it with an inkjet printer, well I'm sure I could, but
> the LJ prints the artwork in 20 seconds, none of my three InkJet and do
> that !
> 
> If anyone has a problem with this kind of board lets hears some sensible
> arguments, tell me why it's not going to work, and explain the reason
> please...
> 
> As far as I'm concerned the issue that  Laser Jet's are not good, is now
> put to rest once and for all.
> I suspect the people that tried LJ's may have had poor results because
> of bad media, or toner cartridge may have been low, or both.

I'd just like to know if anyone has done fine-pitch 256 pin fpga or cpu
boards with a laser...

> I'd just like to know if anyone has done fine-pitch 256 pin fpga or cpu
> boards with a laser...
>
>
The printer is not as big an issue as you think. I have done boards with
FPGA on them in the past with a laser printer. All of my boards have been
made with laser. I made them for a customer. He complimented the work and
ordered more. Quit running down laser printers and look closer at your
process. It is getting tiresome to hear the same ranting and raving about
the printer type on this list. Others have mentioned that they have had
success with them. If you have been following the thread, someone has also
mentioned that the transparency type makes a difference. Telling everyone to
avoid laser printers is spreading misinformation and is not helpful to this
list.
-Mike

Mike Putnam wrote:
>>I'd just like to know if anyone has done fine-pitch 256 pin fpga or cpu
>>boards with a laser...
>>
> The printer is not as big an issue as you think. I have done boards with
> FPGA on them in the past with a laser printer. All of my boards have been
> made with laser. I made them for a customer. He complimented the work and
> ordered more. Quit running down laser printers and look closer at your
> process. It is getting tiresome to hear the same ranting and raving about
> the printer type on this list. Others have mentioned that they have had
> success with them. If you have been following the thread, someone has also
> mentioned that the transparency type makes a difference. Telling everyone to
> avoid laser printers is spreading misinformation and is not helpful to this
> list.

I spent 2 years looking for a cheap way to get good consistant print-outs.
Lasers never worked for finer stuff. If you can say definitely that you can do
fpga boards with 8mil tracks and spacing over the lifetime of the printer, i'll
shut up. Also, can you get good alignment for 1mm via pads when doing double-sided
PCBs? (thermal expansion problems). With the right inkjet, i can make perfect
(15x15cm) double-sided boards with 0.8mm track and spacing and 64pin 0.1" connectors
with no alignment problems with 0.8/1.0mm via pads. I do get some breaks and
shorts because of dust or "stuck" resist. Suitable inkjets (like epson stylus colour)
go for $5 or give-away on ebay while lasers cost a lot more.

Russell Shaw wrote:
> Hans Wedemeyer wrote:
>>
>>As far as I'm concerned the issue that  Laser Jet's are not good, is now
>>put to rest once and for all.
>>I suspect the people that tried LJ's may have had poor results because
>>of bad media, or toner cartridge may have been low, or both.
> 
> 
> I'd just like to know if anyone has done fine-pitch 256 pin fpga or cpu
> boards with a laser...
> 

I've just got a cheapy Cannon S330 (600 x 600 DPI black) that I 
will test soon for PCB photomasks. It has AUD$9 black ink carts.
It would be interesting to see tests from the better Cannon 
inkjets with "1200x2400 DPI black" print modes.

Assuming its possible to print dark and solid like the 
Epson/Epson transparency (no pin holes) then its up to how 
straight the line edges are. I'm not sure if inkjet manufactures 
are improving on this since I don't think accurate dot placment 
is important for photo reproduction.

Adam

Mike,
That's the reason I posted this today.... I'm also sick of the same old
crap about lasjer jet not being any good... it really is
misinformation...

The other point that I can't abid is them needless search for absolute
blackness in the film... Special this and special that... hog wash...

I use MSOP a lot of the time that's 0.0256" (0.65mm) and have no problem
at all.
With regards to 8 mil..... well I demonstrated today,  10 mil is run of
the mil and 8 mil is just as easy.

I remember a stupid board I was presented with some years ago, it was a
very simple circuit about 10 components and the board was about 4" X 4"
( Deer feeder controller)  and the person used 8 mil lines and the
smallest pads ! When they tried to change components of course without a
vacuum driven desoldering tool, pads lifted of and traces got broken.
The golden rule is when you have the space USE IT....

I can do 5 mil if I use Apollo CG7060 film, 3M  CG 3300 is only good to
10 mil (8 at a stretch, with some touch up afterwards)

During the years I have trashed two Epson Inkjet (700 dpi) printers
because the nozzles got blocked and I tried everything to devolve the
hardened ink, but  nothing worked. At the time Epson offered a head
replacement for $130.... I went out and purchased a HP inkjet printer
instead for less.

If people are dumping Epson Inkjet printers for $5 I'd say good luck to
anyone buying one, perhaps buy two and hope the parts are
interchangeable... There are also good deals on eBay for HP Laser
Jets...
I've only put one new toner in this LaserJet since I purchased it two
years ago, my other one (same type, yes I have 5 printers...) is about 6
months older than that and it's on the third toner.
I buy real HP toners for about $48....  I wonder what Epson's inkjet
cartridges cost... !

Hans W


Mike Putnam wrote:

>
> > I'd just like to know if anyone has done fine-pitch 256 pin fpga or
> cpu
> > boards with a laser...
> >
> >
> The printer is not as big an issue as you think. I have done boards
> with
> FPGA on them in the past with a laser printer. All of my boards have
> been
> made with laser. I made them for a customer. He complimented the work
> and
> ordered more. Quit running down laser printers and look closer at your
>
> process. It is getting tiresome to hear the same ranting and raving
> about
> the printer type on this list. Others have mentioned that they have
> had
> success with them. If you have been following the thread, someone has
> also
> mentioned that the transparency type makes a difference. Telling
> everyone to
> avoid laser printers is spreading misinformation and is not helpful to
> this
> list.
> -Mike
>
>
>
>
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[Non-text portions of this message have been removed]

>If you can say definitely that you can do
> fpga boards with 8mil tracks and spacing over the lifetime of the printer,
i'll
> shut up. Also, can you get good alignment for 1mm via pads when doing
double-sided
> PCBs? (thermal expansion problems). With the right inkjet, i can make
perfect
> (15x15cm) double-sided boards with 0.8mm track and spacing and 64pin 0.1"
connectors
> with no alignment problems with 0.8/1.0mm via pads. I do get some breaks
and
> shorts because of dust or "stuck" resist. Suitable inkjets (like epson
stylus colour)
> go for $5 or give-away on ebay while lasers cost a lot more.

Russell,
Where are you finding these $5 and give away printers on E-Bay? I have been
looking for a cheap one to tear apart and try the inkjet straight to a PCB
idea that was on this list earlier.
With a laser printer, I have gone down to 7 mil track and spacing. I have
never needed to go smaller than this on traces and it works fine. I have
never had to deal with breaks or shorts from a laser print. There is some
distortion on larger boards near the end of the print, but if you print in
the same direction from both transparencies, the distortion is not usually
noticable from side to side. The distrtion is also not enough to cause a
problem with parts distance or alignment/size. Any distortion that is a
problem is fixed easily in Acrobat distiller. Like Hans said, you do not
need total blackness. The trick is to get all the traces and pads the same
color, whatever shade of black or grey that may be. If it is consistent,
then it is all a matter of your exposure distance, time and light source.
Best regards,
-Mike

Hans Wedemeyer wrote:
 > Mike,
 > That's the reason I posted this today.... I'm also sick of the same old
 > crap about lasjer jet not being any good... it really is
 > misinformation...

Show me a footprint of 0.5mm pitch 256 pin QFP done on a laser without
most of the pads shorting and i'll be happy.

 > The other point that I can't abid is them needless search for absolute
 > blackness in the film... Special this and special that... hog wash...

The blacker the film, the less critical the exposure.

 > I use MSOP a lot of the time that's 0.0256" (0.65mm) and have no problem
 > at all.

26mil is huge.

 > With regards to 8 mil..... well I demonstrated today,  10 mil is run of
 > the mil and 8 mil is just as easy.

Fine-pitch footprint?

 > I remember a stupid board I was presented with some years ago, it was a
 > very simple circuit about 10 components and the board was about 4" X 4"
 > ( Deer feeder controller)  and the person used 8 mil lines and the
 > smallest pads ! When they tried to change components of course without a
 > vacuum driven desoldering tool, pads lifted of and traces got broken.
 > The golden rule is when you have the space USE IT....

Most of the time i use 20mil tracks and 60-80mil vias.

 > I can do 5 mil if I use Apollo CG7060 film, 3M  CG 3300 is only good to
 > 10 mil (8 at a stretch, with some touch up afterwards)
 >
 > During the years I have trashed two Epson Inkjet (700 dpi) printers
 > because the nozzles got blocked and I tried everything to devolve the
 > hardened ink, but  nothing worked. At the time Epson offered a head
 > replacement for $130.... I went out and purchased a HP inkjet printer
 > instead for less.

Using crap ink i guess. I've used refill stuff just for printing
on paper and sometimes it gets clogged after a few months. The best
way to get it working again is to put in a genuine cartridge and
it flushes the old crap real easy.

 > If people are dumping Epson Inkjet printers for $5 I'd say good luck to
 > anyone buying one, perhaps buy two and hope the parts are
 > interchangeable... There are also good deals on eBay for HP Laser
 > Jets...

I just got a lexmark 4039 R+ 1200dpi, extra paper tray, duplexer (double-
sided printing:), network card, 16ppm for AUS$200 off ebay.com.au.
Great for printing big manuals;)

 > I've only put one new toner in this LaserJet since I purchased it two
 > years ago, my other one (same type, yes I have 5 printers...) is about 6
 > months older than that and it's on the third toner.
 > I buy real HP toners for about $48....  I wonder what Epson's inkjet
 > cartridges cost... !

Black costs AUS$25-35, but i make them last 6 months to a year by using
it only for PCBs. Laser is much cheaper for paper printing.

Mike Putnam wrote:
...
 >>go for $5 or give-away on ebay while lasers cost a lot more.
 >
 > Russell,
 > Where are you finding these $5 and give away printers on E-Bay? I have been
 > looking for a cheap one to tear apart and try the inkjet straight to a PCB
 > idea that was on this list earlier.

Enter: epson stylus
into the ebay search box. For ebay.com.au, the first hit is a stylus C20SX
for $5 with 3 hours to go.

http://search.ebay.com.au/search/search.dll?MfcISAPICommand=GetResult&ht=1&cgiurl=http%3A%2F%2Fcgi.ebay.com.au%2Fws%2F

http://www.sold.com.au
Stylus 460 for $1: http://au.list.sold.yahoo.com/au/23416-category-leaf.html

Past auctions (may need to be logged in):
Stylus C41UX for AUS$67: http://au.page.sold.yahoo.com/au/auction/512163531?aucview=closed
Stylus 480 for $7.50: http://au.page.sold.yahoo.com/au/auction/512025039?aucview=closed
Stylus 660 for $15.50: http://au.page.sold.yahoo.com/au/auction/512025038?aucview=closed
Stylus 680 for AUS$43: http://au.page.sold.yahoo.com/au/auction/511961776?aucview=closed

The market is flooded with cheap printers, motherboards, monitors, and old (but still fast) PCs.

Beware that with the inkjet method, the proper ink and transparency *will* cost more
than the printer.

 > With a laser printer, I have gone down to 7 mil track and spacing. I have
 > never needed to go smaller than this on traces and it works fine. I have
 > never had to deal with breaks or shorts from a laser print. There is some
 > distortion on larger boards near the end of the print, but if you print in
 > the same direction from both transparencies, the distortion is not usually
 > noticable from side to side. The distrtion is also not enough to cause a
 > problem with parts distance or alignment/size. Any distortion that is a
 > problem is fixed easily in Acrobat distiller. Like Hans said, you do not
 > need total blackness. The trick is to get all the traces and pads the same
 > color, whatever shade of black or grey that may be. If it is consistent,
 > then it is all a matter of your exposure distance, time and light source.
 > Best regards,
 > -Mike

>I spent 2 years looking for a cheap way to get good consistant print-outs.
>Lasers never worked for finer stuff. If you can say definitely that you can do
>fpga boards with 8mil tracks and spacing over the lifetime of the printer, i'll
>shut up. Also, can you get good alignment for 1mm via pads when doing double-sided
>PCBs? (thermal expansion problems). With the right inkjet, i can make perfect
>(15x15cm) double-sided boards with 0.8mm track and spacing and 64pin 0.1" connectors
>with no alignment problems with 0.8/1.0mm via pads. I do get some breaks and
>shorts because of dust or "stuck" resist. Suitable inkjets (like epson stylus colour)
>go for $5 or give-away on ebay while lasers cost a lot more.

Russel,

I just lately experimented a lot (well, was forced to do so due to the
transition to through hole plated boards). My findings were that the
printer is really only half of the story. The exposing process AND
also the type of photoactive coating have a huge impact too. I used to
sucessfully and happyly work with regular tracing paper and a HP
LaserJet 4P. By using high quality precoated PCB base material this
worked (and still does of course) very well and I could do 8 mil
traces without problems and repeatable results. Now that I use dry
film resist that I laminate onto the pure copper plated base material
things are different. The main problem with the laser is that all the
film medias I tried (tracing paper, transparencies, different brands
of films for laser, regular paper etc) all were not black enough for
the dry film resist which is magnitudes more light sensitive than the
pre coated material I had. Since I figure that most people on this
list are not laminating dry film photoresist I think that lasers CAN
do really well. Again, the laser is just one part of the process and
if the other material /processing does not match one could get the
impression that lasers were inferior.

What is true (acording to my personal experiennce of course only) is
that there can be problems with propper alignement, but acording to my
experinece this is only then an issue if you use a CNC drilling
machine. For PCB's that are drilled manually this should not matter
cause the miss allignement is the same for both sides of the print if
the output of the artwork is placed at the same spot of the
transparency used.

So, lasers are IMHO a very good option for good quality pre coated
material which I figure is what most people use. 

In order to work with the dry film photoresist I use an epson stylus
C62 which is very cheap ($80), so getting one did not hurt that much.
I did not had the time to find out why this printer is giving so much
better results that the HP DeskJet. After experimenting three days
long I was just happy to have a working setup. Eventually it boils
down to the kind of Ink the different products are using or whatever -
again, I was happy to have a really good working setup.

I also agree with the other poster that there are quality differences
among different products, but the epson stands here exclusively to
produce films and should it break in a year or so I will happyily
spend another $80 to get a replacement.

Markus

i believe that it is possible. i don't doubt that.

but with my old laser jet IIID and with a bad cheap toner and with poor 
cheap ohp transparencys i can't to it.
even on 1mm tracks the center is missing toner. not to talk about ground 
planes...

i think it is possible to make good films with a laser, also with mine.
but it is also possible to make bad films, with only one bad component 
(film, toner, printer).

regards
stefan

On Thu, 03 Jul 2003 09:48:34 +0200, you wrote:

>i believe that it is possible. i don't doubt that.
>
>but with my old laser jet IIID and with a bad cheap toner and with poor 
>cheap ohp transparencys i can't to it.
>even on 1mm tracks the center is missing toner. not to talk about ground 
>planes...

No surprize with most transparencies. Have you ever tried it with
regular tracing paper? Then, the LjIII series of printers were only
300DPI, so this may also impose a serious limit.

>i think it is possible to make good films with a laser, also with mine.
>but it is also possible to make bad films, with only one bad component 
>(film, toner, printer).

The latter is surely not too difficult :-)))

Markus

i have tried with some different transparencys.
but not with tracing paper - didn't see it here anywhere.

the problem is i can't go out and buy "appollo transparencys" because i 
know they work.
they are simply not sold here (as far as i know)....

so i have to experiment myself...


st

>i have tried with some different transparencys.
>but not with tracing paper - didn't see it here anywhere.

Tracing paper is sold in any paper shop. As you know, I'm also from
europe (Switzerland) and as said, every shop should have it. I haven't
found big differences among them. Maybe it's worth a try? Note thouhg
that due to the not so 100% transparency nature of tracing paper
exposure time may have to be increased a little. 

>the problem is i can't go out and buy "appollo transparencys" because i 
>know they work.
>they are simply not sold here (as far as i know)....

Yep, such things often become a problem

>so i have to experiment myself...

Well, at lest somtimes it's fun - somtimes it get's harder. I figure
it depends on the amount of time available.

Markus

I've been doing 100 a few tqfp's that work pretty well.  I've just 
started using toner transfer for the last little while;  I'm sold on 
it.

Pictures
http://wheedal.dyndns.org:8255

> I'd just like to know if anyone has done fine-pitch 256 pin fpga or 
cpu
> boards with a laser...

Very nice.... I'm impressed... bu then Laser can't do this... right ?
:-)
Hans W

wheedal99 wrote:

>  I've been doing 100 a few tqfp's that work pretty well.  I've just
> started using toner transfer for the last little while;  I'm sold on
> it.
>
> Pictures
> http://wheedal.dyndns.org:8255
>
> ? I'd just like to know if anyone has done fine-pitch 256 pin fpga or
> cpu
> ? boards with a laser...
>
>
>                    Yahoo! Groups Sponsor


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> Be sure to visit the group home and check for new Bookmarks and files:
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[Non-text portions of this message have been removed]

For small runs, toner transfer is definitely the way to go.
What is your strategy for separating the paper from the PCB
after you've ironed? It looks very clean.


--- In Homebrew_PCBs@yahoogroups.com, "wheedal99" <wheedal@h...> wrote:

> I've been doing 100 a few tqfp's that work pretty well.  I've just 
> started using toner transfer for the last little while;  I'm sold on 
> it.
> 
> Pictures
> http://wheedal.dyndns.org:8255
> 
> > I'd just like to know if anyone has done fine-pitch 256 pin fpga or 
> cpu
> > boards with a laser...

Well, I meant to say a few 100 pin tqfps, but the results are the 
same...  I use a cheap laminator to fuse the toner and just soak the 
magazine backing off with dishsoap and water, usually peels off 
intact after 30 seconds.  Rub off some of the paper pulp.  I'm 
pleased with the results.  I don't run into very many instances 
anymore that I need to do a home prototype and have to break out the 
photo resist stuff.  I did a preliminary write up of what I do that's 
at the same link --it isn't written very well and some details are 
missing, but you can get the jist.

-Dal
 

--- In Homebrew_PCBs@yahoogroups.com, "rolanyang" <rolan@h...> wrote:

> For small runs, toner transfer is definitely the way to go.
> What is your strategy for separating the paper from the PCB
> after you've ironed? It looks very clean.

> > Pictures
> > http://wheedal.dyndns.org:8255

>  > Where are you finding these $5 and give away printers on E-Bay? I have
been
>  > looking for a cheap one to tear apart and try the inkjet straight to a
PCB
>  > idea that was on this list earlier.
>
> Enter: epson stylus
> into the ebay search box. For ebay.com.au, the first hit is a stylus C20SX
> for $5 with 3 hours to go.
>
>
http://search.ebay.com.au/search/search.dll?MfcISAPICommand=GetResult&ht=1&c
giurl=http%3A%2F%2Fcgi.ebay.com.au%2Fws%2F
>
> http://www.sold.com.au
> Stylus 460 for $1:
http://au.list.sold.yahoo.com/au/23416-category-leaf.html
>
Thanks, but the shipping from AU to US would not be worthwhile for a $5
printer.
-Mike

Hans Wedemeyer wrote:
> Very nice.... I'm impressed... bu then Laser can't do this... right ?
> :-)
> Hans W
> 
> wheedal99 wrote:
> 
> 
>> I've been doing 100 a few tqfp's that work pretty well.  I've just
>>started using toner transfer for the last little while;  I'm sold on
>>it.

Try doing a whole board. I've never got all the pads or tracks to
stick, and i even made special heated press from 5/8" aluminium slabs
to get even pressure and temperature control. The other problem is
that the pressure can cause tracks to be flattened which makes them
spread wider causing ragged edges and shorts.

Mike Putnam wrote:
>> > Where are you finding these $5 and give away printers on E-Bay? I have
>> been looking for a cheap one to tear apart and try the inkjet straight to a
>> PCB idea that was on this list earlier.
>>
>>Enter: epson stylus
>>into the ebay search box. For ebay.com.au, the first hit is a stylus C20SX
>>for $5 with 3 hours to go.
> 
> http://search.ebay.com.au/search/search.dll?MfcISAPICommand=GetResult&ht=1&c
> giurl=http%3A%2F%2Fcgi.ebay.com.au%2Fws%2F
> 
>>http://www.sold.com.au
>>Stylus 460 for $1:
> 
> http://au.list.sold.yahoo.com/au/23416-category-leaf.html
> 
> Thanks, but the shipping from AU to US would not be worthwhile for a $5
> printer.
> -Mike

The US list has similar prices.

I'm not sure what you mean by a "whole board".  Almost everything I 
do is under 6"x6".  Anything larger, or more complicated I send out.  
Ordering boards is fairly inexpensive these days so the only reason I 
do some of them myself is to save time.  What were you trying to do 
that didn't work?
--- In Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@i...> 
wrote:
> Hans Wedemeyer wrote:
> Try doing a whole board. I've never got all the pads or tracks to
> stick, and i even made special heated press from 5/8" aluminium 
slabs

> to get even pressure and temperature control. The other problem is
> that the pressure can cause tracks to be flattened which makes them
> spread wider causing ragged edges and shorts.

Small correction here....
You quote me       >Hans Wedemeyer wrote:

Not me... I think someone  wrote :-
> Try doing a whole board. I've never got all the pads or tracks to
> stick, and i even made special heated press from 5/8" aluminium
slabs
> to get even pressure and temperature control. The other problem is
> that the pressure can cause tracks to be flattened which makes them
> spread wider causing ragged edges and shorts.

Best regards
Hans W


wheedal99 wrote:

>  I'm not sure what you mean by a "whole board".  Almost everything I
> do is under 6"x6".  Anything larger, or more complicated I send out.
> Ordering boards is fairly inexpensive these days so the only reason I
> do some of them myself is to save time.  What were you trying to do
> that didn't work?
> --- In Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@i...>
> wrote:
> > Hans Wedemeyer wrote:
> > Try doing a whole board. I've never got all the pads or tracks to
> > stick, and i even made special heated press from 5/8" aluminium
> slabs
> > to get even pressure and temperature control. The other problem is
> > that the pressure can cause tracks to be flattened which makes them
> > spread wider causing ragged edges and shorts.
>
>


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

wheedal99 wrote:

> --- In Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@i...> 
> wrote:
>>Try doing a whole board. I've never got all the pads or tracks to
>>stick, and i even made special heated press from 5/8" aluminium 
>> slabs to get even pressure and temperature control. The other problem is
>>that the pressure can cause tracks to be flattened which makes them
>>spread wider causing ragged edges and shorts.

 > I'm not sure what you mean by a "whole board".  Almost everything I
 > do is under 6"x6".  Anything larger, or more complicated I send out.
 > Ordering boards is fairly inexpensive these days so the only reason I
 > do some of them myself is to save time.  What were you trying to do
 > that didn't work?

I was trying to get the normal laser printer toner-transfer system to
work for 'normal' 10cm x 10cm PCBs. I was using TTS paper that has a
gelatine coating that dissolves in water. The proper fuser thing costs
US$200 (~AUS$300 then plus postage overseas) so i made my own. I got
a 2.4kW spiral stove element and fastened it to a 30cm x 40cm x 16mm
slab of aluminium. I made a triac control with temperature feedback.
I had a second slab with insulated handle that sits on top. I let the
whole lot preheat before putting the pcb between. I tried varying
temperature, pressure, and cleaning/degreasing the pcb in various
ways, but i would always get a couple of pads or tracks falling off
in the water. Pressing the pcb harder would make the toner stick
better, but then there'd always be some tracks or pads that increased
in area because the toner was flattened. Later, i tried just lasering
onto transparencies, but you could easily say light thru the large
black areas and the resolution was not sharp. Printers were HP laserjet-II
and HP 4M+.

I then experimented with canon, HP, and epson inkjets using
genuine inks and transparencies. The epson stylus color was miles ahead
because they had transparency that absorbs the ink into a flat surface.
Large black areas have not a single pinhole and edges are sharp.
The other printers had "sandpapery" rough transparency that relied on
mechanical adhesion rather than chemical compatibility. They had rougher
edges, pinholing, and took much longer to dry. From what i found,
thermal heads seem to clog more than piezo heads, unless crappy refill
ink is used (anecdotal evidence). IIRC, some printers like HP have the
head built into the cartridge. Epson heads are part of the printer and
the cartridge is only a container.

It was ~5 years ago, and i haven't tried lexmark inkjets or newer
lasers. Lasers are probably better now, and are worth using if you
already have one and its resolution and contrast is *adequate*.
There are many very cheap inkjets and lasers on ebay.

One thing to beware of: with inkjets, after the ink is dried, it can
still be outgassing a vapour that wrecks photoresist that doesn't
have the plastic sheet layer. This happens with the epson transparency
and PRP spray-on resist. To fix, put the printout in front of a fan
heater for 10-15mins before using. It is very important to fully degrease
the copper before spraying with PRP. Vinegar with lots of salt works well.

Well, it sounds like we're talking about the same thing.  10cmx10cm 
is pretty typical for me as well...  The board pictured on the 
earlier site post is ~7cmx10cm.  I'm using a >5 year old HP laserjet 
5L that's been working for me pretty well (2nd genuine HP toner 
cartridge).  I use a paper laminator as the fuser and magazine stock 
as the transfer medium.  I too had somewhat dubious results with the 
press n peel stuff; but I was using a hand iron at the time.  The 
critical part, as with what you say about the spray photo resist, is 
to get the stock very clean  --otherwise the toner doesn't perform 
well.  When I have dropout problems it's usually due to not cleaning 
the board properly, not cleaning the board edges when I cut down 
stock (jagged edges left by the linoleum knife can give the surface 
an uneven pressing in the laminator), or not getting the board hot 
enough (too few passes through the laminator).  All of this can be 
corrected quickly, (clean the board and start again).  With a little 
practice you can get it right most of the time with no dropout.  

One thing that this method won't do is large flooded areas --at least 
with my printer.  I don't think the HP 5L puts down even coverage 
when covering large surfaces.  If I need to have flooded regions, I 
go through with a staedler marker and touch up the fallout.

For quick and dirty boards, you can get a lot of milage out of this 
method.  

I understand you've got a printer/photo process that works well for 
you, but maybe someone who has a different setup might be able to get 
results they're happy with using a laser printer they already have.

-Dal

PS I'll be putting a few more photos and fixing the howto text soon.
http://wheedal.dyndns.org:8255

----- Original Message ----- 

From: "wheedal99" <wheedal@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, July 06, 2003 4:58 AM
Subject: [Homebrew_PCBs] Re: the naked truth about Laser Jet, warts and all
!


>
> One thing that this method won't do is large flooded areas --at least
> with my printer.  I don't think the HP 5L puts down even coverage
> when covering large surfaces.  If I need to have flooded regions, I
> go through with a staedler marker and touch up the fallout.
>

I use cross-hatching on copper pour areas with my LJ IIIp. They come out
very well. Worth trying if your CAD software does it (Pulsonix does).

Leon
--
Leon Heller, G1HSM
leon_heller@...
http://www.geocities.com/leon_heller

I fixed /added a few things to the "howto".  The newer direct link is:
http://myweb.cableone.net/wheedal/pcb.htm

Let me know if there are any glaring errors or too skimpy in any 
areas.
Thanks,
Dal

--- In Homebrew_PCBs@yahoogroups.com, "wheedal99" <wheedal@h...> > PS 
I'll be putting a few more photos and fixing the howto text soon.
> http://wheedal.dyndns.org:8255

> As far as I'm concerned the issue that  Laser Jet's are not good, 
is now
> put to rest once and for all.
> I suspect the people that tried LJ's may have had poor results 
because
> of bad media, or toner cartridge may have been low, or both.

A friend of mine using a LaserJetIII also suggested to send a couple 
of prints through the printer prior to sending the final artwork, so 
the unit get's a chance to heat up.

- Carsten