Homebrew PCBs

Well, I finally broke down and bought one of these on sale from 
Staples  ($65 + tax).  

Overall, I like it but it did take some getting used to and its far 
from perfect.

First off, I tried the unmodified laminator with some 32 mil boards.  
It worked fairly well and took about 8 passes through to get 
sufficient toner adhesion.  Basically, one needs to get the board hot 
enough to fuse the toner and that's why so many passes.  The trick is 
to keep the board in laminator as much as possible - as soon as its 
out, feed it right back in the front.  I got pretty good at telling 
when the proper temperature had been reached (i.e. enough passes had 
been made) by touching the board with my fingers.  You also want to 
feed the wider edge of the board to increase the heating area per 
pass.   I trim my paper to have about a 2" border around the board.

I really prefer the 64 mil boards (structurally more sound) so I went 
ahead and make the mods as described on the pulsar site.  The 
instructions are pretty good but I'd suggest reading them carefully 
before opening the case up and once you have the motor/roller 
assembly out, re-read them.  The instructions would be really great 
if there were pictures.   The hardest part is changing the motor 
mount and gearing - the pulsar doc does it in two seperate steps but 
I found it easier to do it as one step.

So I got it back together and fired it up.  There was a clunk when I 
turned it on but it seemed to feed paper ok so I put in a test 64 mil 
board.  It feeds a board ok but makes another clunk when the board 
exits the rollers (as they snap together, I assume).  You can see the 
board jump forward about 1/4" when this happens.  At least there is a 
lot of pressure on the board/paper assembly

I found that when feeding 64 mil stuff, you really need to make a 
*lot* of passes.  20 seems to work ok.  I did a number of boards, the 
largest being 6" x 2.75".  The results are pretty good - nicely 
uniform adhesion and reasonably clean traces.

My biggest issue is alignment of the toner pattern for double sided 
boards.  The pinch rollers tend to pull the top paper so I had to 
resort to using an iron to tack the paper onto the board before 
feeding it.

So, is it better than ironing?  Yes but not as much as I would have 
thought.  The results are more uniform than ironing, especially for 
larger boards.  For smaller ones (2"x3" or so), an iron will produce 
similar results.  People who are making small boards won't benefit as 
much.  Also, given the number of passes you have to make, ironing is 
a little faster.  Another issue I found is that you need to let the 
device warm up even after the light comes on.  If you feed a board as 
soon as the light comes on, about halfway through the light will go 
off indicating that the board cooled off the heater.  I let it warm 
up about 5 minutes more.  Overall, ironing is faster.

One thing I am thinking about doing is figuring out how to slow the 
feed motor to expose the board to more heat for a longer time.  The 
objective is to do the board in a single pass.  Anyone done that?

Phil

> First off, I tried the unmodified laminator with some 32 mil boards.
> It worked fairly well and took about 8 passes through to get
> sufficient toner adhesion.  Basically, one needs to get the board hot
> enough to fuse the toner and that's why so many passes.  The trick is
> to keep the board in laminator as much as possible - as soon as its
> out, feed it right back in the front.

That's the impression i get too.
It's why i have made my fuser _really_ slow and only need 1 pass now.
It seems more reasonable to heat it in one pass to full temperature  
because obviously
there is no chance to cool in between. If you need multiple passes longer  
boards might
need more passes than shorter ones.



> I found that when feeding 64 mil stuff, you really need to make a
> *lot* of passes.  20 seems to work ok.  I did a number of boards, the
> largest being 6" x 2.75".  The results are pretty good - nicely
> uniform adhesion and reasonably clean traces.

that's really a lot of passes?
how long does one page take to feed completely?

>
> My biggest issue is alignment of the toner pattern for double sided
> boards.  The pinch rollers tend to pull the top paper so I had to
> resort to using an iron to tack the paper onto the board before
> feeding it.

I have exactly the same trouble and so far not found a reasonable  
workaround.

>
> So, is it better than ironing?  Yes but not as much as I would have
> thought.  The results are more uniform than ironing, especially for
> larger boards.  For smaller ones (2"x3" or so), an iron will produce
> similar results.  People who are making small boards won't benefit as
> much.  Also, given the number of passes you have to make, ironing is
> a little faster.  Another issue I found is that you need to let the
> device warm up even after the light comes on.  If you feed a board as
> soon as the light comes on, about halfway through the light will go
> off indicating that the board cooled off the heater.  I let it warm
> up about 5 minutes more.  Overall, ironing is faster.

Only with your GBC H200 which is in my opinion far from a good idea.
The fuser is really nice, i usually turn it on before starting to clean  
the PCB,
but it is hot a lot faster than that time. On pass (2 passes for  
double-sided or
broad tracks) is really not that long, and hugely easier than ironing.

>
> One thing I am thinking about doing is figuring out how to slow the
> feed motor to expose the board to more heat for a longer time.  The
> objective is to do the board in a single pass.  Anyone done that?

See above.


I thing the alignment problem could be solved by "tacking" the paper to  
the board
with a iron. I haven't tried so far. I must really find a solution to that  
alignment problem,
it is very annoying.

ST

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
...
> > I found that when feeding 64 mil stuff, you really need to make a
> > *lot* of passes.  20 seems to work ok.  I did a number of boards, 
the
> > largest being 6" x 2.75".  The results are pretty good - nicely
> > uniform adhesion and reasonably clean traces.
> 
> that's really a lot of passes?
> how long does one page take to feed completely?
> 

The time of a pass is dependent on how long the paper/board assembly 
is.  For the 6x2.75" board it was about 5" and it took around 25 
seconds.  So you can see, a big board gets tedious

> >
> > My biggest issue is alignment of the toner pattern for double 
sided
> > boards.  The pinch rollers tend to pull the top paper so I had to
> > resort to using an iron to tack the paper onto the board before
> > feeding it.
> 
> I have exactly the same trouble and so far not found a reasonable  
> workaround.
> 

as I said in the original posting, I use an iron to tack it down.  
With the paper/board assembly lying flat, I start with the iron in 
the middle and go back and forth.  This I flip it over and do the 
same.  It works ok but my wife wants her iron back :)

...
> 
> Only with your GBC H200 which is in my opinion far from a good idea.
> The fuser is really nice, i usually turn it on before starting to 
clean  
> the PCB,
> but it is hot a lot faster than that time. On pass (2 passes for  
> double-sided or
> broad tracks) is really not that long, and hugely easier than 
ironing.

I may yet build a PCB fuser from an old HP LJII I have but its more 
of a project than I want to tackle right now.  Besides, I've kind of 
been waiting for you to post detailed instructions.  lol   By the 
way, I believe this isn't just my H200 but all H200s.

> My biggest issue is alignment of the toner pattern for double sided 
> boards.  The pinch rollers tend to pull the top paper so I had to 
> resort to using an iron to tack the paper onto the board before 
> feeding it.
> 
I have this same kind of laminator. Assuming the packaging is the same
there should have been a sheet of heavy paper included. I took that
paper, folded it in half and put my two sided board inside and solid
against the fold. Leave enough overhang so that when you feed into the
laminator the paper is grabbed first. Keep a tight grip on the paper,
pc board sandwich until board is in between the rollers. If you do not
have the paper I have also used heavy construction paper. Ordinary
notebook paper tended to crumple up rather than coming out the back.

With this technique I have had no problems with maintaining alignment.
This also comes in handy with boards that are too small to appear out
the back side before it has fed all the way through. 

I will mention one other thing about my laminator. I did no
modifications and after about a years worth of use the gears have
started to strip. So I will have to replace mine in the near future.  

With my boards I generally found it took any where from 6-10 passes. I
also  found it also useful with my larger boards to rotate the board
so that different edges fed in first. This helped with problems with
the edges not getting a good transfer.

--- In Homebrew_PCBs@yahoogroups.com, "javaguy11111" 
<javaguy11111@y...> wrote:
...
> > 
> I have this same kind of laminator. Assuming the packaging is the 
same
> there should have been a sheet of heavy paper included. I took that
> paper, folded it in half and put my two sided board inside and solid
> against the fold. Leave enough overhang so that when you feed into 
the
> laminator the paper is grabbed first. Keep a tight grip on the 
paper,
> pc board sandwich until board is in between the rollers. If you do 
not
> have the paper I have also used heavy construction paper. Ordinary
> notebook paper tended to crumple up rather than coming out the back.

I'll give it a try.  thanks. I leave about a 1" border on the paper 
so there I can pull the small boards out.  I've not had any problem 
with the paper getting caught in the machine.

> 
> With this technique I have had no problems with maintaining 
alignment.
> This also comes in handy with boards that are too small to appear 
out
> the back side before it has fed all the way through. 

I saw about 5 mils of misalignment before I started tacking with the 
iron.

> With my boards I generally found it took any where from 6-10 
passes. I
> also  found it also useful with my larger boards to rotate the board
> so that different edges fed in first. This helped with problems with
> the edges not getting a good transfer.

Yeah, I flip my boards over for each pass.  I took careful notes of 
my first 5 attempts.  On the 64 mil stuff, 12 passes wasn't enough 
and 16 had some lifting of traces but 20 did it.  I wonder if they've 
tweaked the design or its normal variation in manufacturing.

What kind of pcb material are you using? I'm using 0.064 FR4 1 oz

Phil - I too found the instructions without pictures frustrating, but
did manage to get the conversion done - but not as quickly as Frank
(Pulsar) predicted though.

I did have a problem Frank did not mention. The PCB's (64 thou) would
not go through most of the time! I did some damage to the rollers
though they seem to work ok in spite of that. Eventually I determined
that the two plates at the rear of the roller were too close together
and so were preventing the PCB's from passing. 

It was simple enough (when I finally figured it out) to shim the top
plate up (closer to the roller) at a slight angle with some little
pieces of 30 thou PCB, inserted at the two back retaining slots or
whatever you call them. Since then there has been no problem. I wonder
if some of your mechanical? problems might be related to that.

I have found that most of my PCB's only need one or two passes. Three
is the most I have ever used. The biggest board I have done so far is
about 2.7 by 5.2", so maybe that's a factor. Bigger boards will aborb
more heat, or need more heat to reach a given temperature than smaller
boards, right?

I know different toners have different melt/fuse temperatures. I am
using a Panasonic KXP-6500 laser printer, and the prescribed Panasonic
toner. I am using Pulsar (formerly Dyna-Art) paper. I am using 64 thou
PCB material (which is apparently only 60 thou, so maybe I did not
need to modify the thing).

Another possible variable is the preparation of the PCB surface - I
use SOS pads to remove oxidation, dirt and grease. They leave the
surface clean and shiny but with some scratching though that's really
not the right term, just that the copper is very slightly roughened.

I find that the laminator is much better than ironing for me, in terms
of consistency, and complete, undistorted toner transfer to the PCB.
It sounds like you are having a lot more frustration than I am. I hope
the group can figure out some solutions to these difficulties.

Grant

--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
> Well, I finally broke down and bought one of these on sale from 
> Staples  ($65 + tax).  
> 
> Overall, I like it but it did take some getting used to and its far 
> from perfect.
[snip]

I can't say I'm having frustrations, just the normal issues with a 
new technique.  

The one thing I see different is that I am using a photocopier (canon 
pc7xx) so the toner may require higher fusing temp.  I really like 
this approach - I print on an inkjet printer that does 1440 dpi.  A 
while ago I tried to track down the fusing temperature for my toner 
but it was harder than getting a straight answer from a politician.

I dont think my board prep is at issue - I use 600 grit wet-or-dry 
sandpaper and degrease with acetone.  Never had a problem.  You 
definitely want to rough up the surface (T&T calls it "activation") 
so that there is more surface area thus making it easier for the 
toner to adhere.  

By the way, you might want switch away from steel based scouring pads 
as it will contaminate the surface of the copper.  I used scotch-
brite for a while but got really good results with 600 grit w-or-d. 
T&T has a cleaning product that I've been thinking of trying.

--- In Homebrew_PCBs@yahoogroups.com, "grantfair2001" 
<grant.fair@s...> wrote:
> Phil - I too found the instructions without pictures frustrating, 
but
> did manage to get the conversion done - but not as quickly as Frank
> (Pulsar) predicted though.
> 
> I did have a problem Frank did not mention. The PCB's (64 thou) 
would
> not go through most of the time! I did some damage to the rollers
> though they seem to work ok in spite of that. Eventually I 
determined
> that the two plates at the rear of the roller were too close 
together
> and so were preventing the PCB's from passing. 
> 
> It was simple enough (when I finally figured it out) to shim the top
> plate up (closer to the roller) at a slight angle with some little
> pieces of 30 thou PCB, inserted at the two back retaining slots or
> whatever you call them. Since then there has been no problem. I 
wonder
> if some of your mechanical? problems might be related to that.
> 
> I have found that most of my PCB's only need one or two passes. 
Three
> is the most I have ever used. The biggest board I have done so far 
is
> about 2.7 by 5.2", so maybe that's a factor. Bigger boards will 
aborb
> more heat, or need more heat to reach a given temperature than 
smaller
> boards, right?
> 
> I know different toners have different melt/fuse temperatures. I am
> using a Panasonic KXP-6500 laser printer, and the prescribed 
Panasonic
> toner. I am using Pulsar (formerly Dyna-Art) paper. I am using 64 
thou
> PCB material (which is apparently only 60 thou, so maybe I did not
> need to modify the thing).
> 
> Another possible variable is the preparation of the PCB surface - I
> use SOS pads to remove oxidation, dirt and grease. They leave the
> surface clean and shiny but with some scratching though that's 
really
> not the right term, just that the copper is very slightly roughened.
> 
> I find that the laminator is much better than ironing for me, in 
terms
> of consistency, and complete, undistorted toner transfer to the PCB.
> It sounds like you are having a lot more frustration than I am. I 
hope
> the group can figure out some solutions to these difficulties.
> 
> Grant
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> 
wrote:
> > Well, I finally broke down and bought one of these on sale from 
> > Staples  ($65 + tax).  
> > 
> > Overall, I like it but it did take some getting used to and its 
far 
> > from perfect.
> [snip]

--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "javaguy11111" 
> <javaguy11111@y...> wrote:
> ...
> > > 
> > I have this same kind of laminator. Assuming the packaging is the 
> same
> > there should have been a sheet of heavy paper included. I took
that
> > paper, folded it in half and put my two sided board inside and
solid
> > against the fold. Leave enough overhang so that when you feed
into 
> the
> > laminator the paper is grabbed first. Keep a tight grip on the 
> paper,
> > pc board sandwich until board is in between the rollers. If you
do 
> not
> > have the paper I have also used heavy construction paper. Ordinary
> > notebook paper tended to crumple up rather than coming out the
back.
> 
> I'll give it a try.  thanks. I leave about a 1" border on the paper 
> so there I can pull the small boards out.  I've not had any problem 
> with the paper getting caught in the machine.
> 
> > 
> > With this technique I have had no problems with maintaining 
> alignment.
> > This also comes in handy with boards that are too small to appear 
> out
> > the back side before it has fed all the way through. 
> 
> I saw about 5 mils of misalignment before I started tacking with
the 
> iron.
> 
> > With my boards I generally found it took any where from 6-10 
> passes. I
> > also  found it also useful with my larger boards to rotate the
board
> > so that different edges fed in first. This helped with problems
with
> > the edges not getting a good transfer.
> 
> Yeah, I flip my boards over for each pass.  I took careful notes of 
> my first 5 attempts.  On the 64 mil stuff, 12 passes wasn't enough 
> and 16 had some lifting of traces but 20 did it.  I wonder if
they've 
> tweaked the design or its normal variation in manufacturing.
> 
> What kind of pcb material are you using? I'm using 0.064 FR4 1 oz

I am using .064 FR4 1oz as well. I use PNP Blue for the transfer. I
use 30gauge wire with a .015 bit for most through holes and have had
no problems with getting a good enough alignment. When I align I use a
small light table and a microscope.

--- In Homebrew_PCBs@yahoogroups.com, "javaguy11111" 
<javaguy11111@y...> wrote:
> 
> I am using .064 FR4 1oz as well. I use PNP Blue for the transfer. I
> use 30gauge wire with a .015 bit for most through holes and have had
> no problems with getting a good enough alignment. When I align I 
use a
> small light table and a microscope.

Like I said, if I tack down before feeding the laminator, it works 
fine.  I get within 1-2 microns.  Aligning the top and bottom isn't 
at all an issue - the laminator was pulling the top sheet slightly.

> 
> I am using .064 FR4 1oz as well. I use PNP Blue for the transfer. I
> use 30gauge wire with a .015 bit for most through holes and have had
> no problems with getting a good enough alignment. When I align I 
use a
> small light table and a microscope.

How do you align ?

Drill before or after ?

I just thought that if one were to drill first, you can put the 
dholes exactly in line with the board and then use the holes as 
guides for the transfer.

Downside is etching the holes.

Dave

--- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" <dave_mucha@y...>
wrote:
> 
> > 
> > I am using .064 FR4 1oz as well. I use PNP Blue for the transfer.
I
> > use 30gauge wire with a .015 bit for most through holes and have
had
> > no problems with getting a good enough alignment. When I align I 
> use a
> > small light table and a microscope.
> 
> How do you align ?
> 
> Drill before or after ?
> 
> I just thought that if one were to drill first, you can put the 
> dholes exactly in line with the board and then use the holes as 
> guides for the transfer.
> 
> Downside is etching the holes.
> 
> Dave

For me, it is easier to etch and then drill.
After printing onto the TT, I will align then tack the two sides
together with scotch tape. I leave a little extra of a tail  on the
side that I will apply the tape to. I also apply tape  to the sides
,along the tail, to minimize any twisting.

Grant,

I'm glad you mentioned the isue of PCBs exiting the laminator; I'll 
watch for it when I do my ocnversion.

Phil, you achieved 2 microns resolution? That is really great!

I've been using 0.032" PCBs so far.

Mike


--- In Homebrew_PCBs@yahoogroups.com, "grantfair2001" 
<grant.fair@s...> wrote:
> Phil - I too found the instructions without pictures frustrating, 
but
> did manage to get the conversion done - but not as quickly as Frank
> (Pulsar) predicted though.
> 
> I did have a problem Frank did not mention. The PCB's (64 thou) 
would
> not go through most of the time! I did some damage to the rollers
> though they seem to work ok in spite of that. Eventually I 
determined
> that the two plates at the rear of the roller were too close 
together
> and so were preventing the PCB's from passing. 
> 
> It was simple enough (when I finally figured it out) to shim the top
> plate up (closer to the roller) at a slight angle with some little
> pieces of 30 thou PCB, inserted at the two back retaining slots or
> whatever you call them. Since then there has been no problem. I 
wonder
> if some of your mechanical? problems might be related to that.
> 
> I have found that most of my PCB's only need one or two passes. 
Three
> is the most I have ever used. The biggest board I have done so far 
is
> about 2.7 by 5.2", so maybe that's a factor. Bigger boards will 
aborb
> more heat, or need more heat to reach a given temperature than 
smaller
> boards, right?
> 
> I know different toners have different melt/fuse temperatures. I am
> using a Panasonic KXP-6500 laser printer, and the prescribed 
Panasonic
> toner. I am using Pulsar (formerly Dyna-Art) paper. I am using 64 
thou
> PCB material (which is apparently only 60 thou, so maybe I did not
> need to modify the thing).
> 
> Another possible variable is the preparation of the PCB surface - I
> use SOS pads to remove oxidation, dirt and grease. They leave the
> surface clean and shiny but with some scratching though that's 
really
> not the right term, just that the copper is very slightly roughened.
> 
> I find that the laminator is much better than ironing for me, in 
terms
> of consistency, and complete, undistorted toner transfer to the PCB.
> It sounds like you are having a lot more frustration than I am. I 
hope
> the group can figure out some solutions to these difficulties.
> 
> Grant
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> 
wrote:
> > Well, I finally broke down and bought one of these on sale from 
> > Staples  ($65 + tax).  
> > 
> > Overall, I like it but it did take some getting used to and its 
far 
> > from perfect.
> [snip]