Homebrew PCBs

On Wed, 30 Oct 2013 17:16:36 +0000, you wrote:

>The results with a flat iron are too variable which laminator is best ?

You're dealing with three variables, pressure, temperature, and time.

You want enough pressure to make sure the toner transfers well, but
not enough to spread it out.  You want a temperature high enough to
make the toner sticky, but not run, and you want to subject the board
to the above two things long enough to make the whole thing work.

For pressure, that depends in part on the thickness of the boards you
are using.  0.020?  0.030?  0.060?  Some boards do not feed through a
laminator well at that thickness, with the thicker boards being the
worst.  You may have to modify the laminator.

Some laser printers have different toner/fuser temperatures, Brother
has some that are higher temperature and don't work well with the run
of the mill laminators.  A laminator with adjustable temperature may
be a partial solution to that.  Modifying the laminator itself will
be, but you have to consider that the laminator may be too hot for the
case.

time you can fix by running the board through multiple times, which I
think most do.

That said, for an HP 2100 series printer, 0.020 boards (single sided),
and Pulsar paper, I get good results with a little GBC "creative"
laminator.  

Your results can vary.

Harvey

>
>Thanks for any advice.
>
>Doug

On 10/31/2013 7:48 AM, Harvey White wrote:
> On Wed, 30 Oct 2013 17:16:36 +0000, you wrote:
>
>  >The results with a flat iron are too variable which laminator is best ?
>
> You're dealing with three variables, pressure, temperature, and time.

Sounds to me like there is no cheap and simple laminator out there that 
is really suitable for our job so I have not bothered buying one.

On the other hand, I seem to be whistling in the graveyard as not a 
single response has been made to my solution to getting it right all the 
time with and iron.

The 3 variables mentioned, if properly controlled produce the required 
environment for the toner to  transfer.

If you use an IR thermometer to measure the board and transfer sheet 
temperature while ironing, you get the same results just by getting the 
temperature right.  It takes time to get it their depending on board 
thickness and a bunch of other stuff and the weight of the iron does not 
change if you just move it around.

If it doesn't work the first time, try a different temp.  If mushy, go 
lower.  If incomplete transfer go higher.  Change nothing else and it 
will work every time (more or less).

I find 300F works well for my stuff so that's a good place to start.

You can buy IR thermometers for less than a laminator and they have lots 
of other uses like making martinis, etc.

Try it.... say something, have a martini,

Jack


Astronomy, Beer, Cheese, Fiber, Gems,
Nature, Radio, Sheep, Sausage, Silver

       http://schmidling.com

On Thu, 31 Oct 2013 08:58:17 -0600, you wrote:

>
>
>On 10/31/2013 7:48 AM, Harvey White wrote:
>> On Wed, 30 Oct 2013 17:16:36 +0000, you wrote:
>>
>>  >The results with a flat iron are too variable which laminator is best ?
>>
>> You're dealing with three variables, pressure, temperature, and time.
>
>Sounds to me like there is no cheap and simple laminator out there that 
>is really suitable for our job so I have not bothered buying one.


The laminator I got cost about 30 to 40 USD.  It has no temperature
setting.   It seems to work well, 144 pin 0.5mm spacing FPGAs with
10/10 spacing.
>
>On the other hand, I seem to be whistling in the graveyard as not a 
>single response has been made to my solution to getting it right all the 
>time with and iron.
>

You won't get one from me, since the laminator I use works fine for me
with the equipment and board thickness I have.

I can do a larger board with the laminator (say 5 x 7) than I can do
with an iron.  If I were doing only a small board, say one that would
fit on an iron, I'd be tempted to use it, but.... that's not my
average board size.

>The 3 variables mentioned, if properly controlled produce the required 
>environment for the toner to  transfer.
>
>If you use an IR thermometer to measure the board and transfer sheet 
>temperature while ironing, you get the same results just by getting the 
>temperature right.  It takes time to get it their depending on board 
>thickness and a bunch of other stuff and the weight of the iron does not 
>change if you just move it around.


And the difference in calibrating your process to a laminator?   Seems
to be the same in either case.  The advantage of the laminator is that
the temperature and pressure are fixed, so if they work.........

>
>If it doesn't work the first time, try a different temp.  If mushy, go 
>lower.  If incomplete transfer go higher.  Change nothing else and it 
>will work every time (more or less).

If incomplete transfer, run through more times, if mushy, try lower
board thickness, if you can adjust the temperature (some can) then go
that way as well.


>
>I find 300F works well for my stuff so that's a good place to start.
>
>You can buy IR thermometers for less than a laminator and they have lots 
>of other uses like making martinis, etc.

Or use an iron-constantan thermocouple on a DMM.... another way.


>
>Try it.... say something, have a martini,
>

Something, and I prefer wine, thank you.....

<grin>

Harvey

>Jack
>
>
>Astronomy, Beer, Cheese, Fiber, Gems,
>Nature, Radio, Sheep, Sausage, Silver
>
>       http://schmidling.com

On 10/31/2013 8:24 PM, Harvey White wrote:

> You won't get one from me, since the laminator I use works fine for me
> with the equipment and board thickness I have.

That's great but it seems like the majority of beginners are having 
problems with the iron.  As they not only can work well but usually 
require zero investment, it is still well worth considering a better way 
of using them.

> And the difference in calibrating your process to a laminator? Seems
> to be the same in either case. The advantage of the laminator is that
> the temperature and pressure are fixed, so if they work.........

True, if there is only one variable, you are home free but this is not 
the case as you still have board size and thickness which effect the 
surface temperature as a function of time.
Also most people have mentioned that it takes more than one pass and I 
have heard of more laminators that don't work or need to be modified 
than from people totally happy with them.


> Or use an iron-constantan thermocouple on a DMM.... another way.

How would you measure the transfer medium temperature with a thermocouple?

The best you could do embed it in whatever the board rests on an measure 
the temperature of that general area.

With the IR meter you can scan the entire surface in about  a second and 
know the temperature of the only place that matters.

  js
-- 


Astronomy, Beer, Cheese, Fiber, Gems,
Nature, Radio, Sheep, Sausage, Silver

       http://schmidling.com