Homebrew PCBs

On 10/18/2013 6:18 PM, twgray2007@... wrote:
> Is anyone else using the HP LaserJet P1006 printer for toner transfer?
> If so, has anyone been able to get the printer to register correctly
> betwen multiple printer passes?

Me thinks you are trying to make a silk purse out of a sow's ear in 
addition to chasing the wrong spook.

Unless  you are  trying to do something special, the  P1006 puts down 
enough toner to do the job in a single pass.  I run mine at 600 dpi and 
all the paper types seem to work about as well.

The critical step is transferring the toner to the board.  If none is 
left behind, you have a winner.  More toner on the paper is not going to 
assure a good transfer. How you get a good transfer is the step you have 
to work out yourself.  There are lots of  ideas out there but I have not 
found one that works 100%. I am still trying.

I don't make bad boards but still make a lot of bad transfers. 
Fortunately, they are nearly free and I have lots of time.

Jack

-- 


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

       http://schmidling.com

Just to clarify, by "paper types" I am referring to printer set up not 
what you are printing on.

js

> Unless you are trying to do something special, the P1006 puts down
> enough toner to do the job in a single pass. I run mine at 600 dpi and
> all the paper types seem to work about as well.


-- 


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

       http://schmidling.com

On Fri, 18 Oct 2013 21:14:10 -0600, you wrote:

>
>
>On 10/18/2013 6:18 PM, twgray2007@... wrote:
>> Is anyone else using the HP LaserJet P1006 printer for toner transfer?
>> If so, has anyone been able to get the printer to register correctly
>> betwen multiple printer passes?
>
>Me thinks you are trying to make a silk purse out of a sow's ear in 
>addition to chasing the wrong spook.
>
>Unless  you are  trying to do something special, the  P1006 puts down 
>enough toner to do the job in a single pass.  I run mine at 600 dpi and 
>all the paper types seem to work about as well.
>
>The critical step is transferring the toner to the board.  If none is 
>left behind, you have a winner.  More toner on the paper is not going to 
>assure a good transfer. How you get a good transfer is the step you have 
>to work out yourself.  There are lots of  ideas out there but I have not 
>found one that works 100%. I am still trying.
>
>I don't make bad boards but still make a lot of bad transfers. 
>Fortunately, they are nearly free and I have lots of time.
>
>Jack
You can also "overcook" the transfer process. If the paper
coating contains certain types of plastic it is quite possible 
to use too much heat for too long and end up fusing the
surface coating into the paper. Note too that the size of the
board often makes a major difference. The mass of copper being
heated and the surface area available to radiate from the board
can make a major difference. With a 2x2 board I iron for about
70 seconds, while a 4x6 board requires about 150 seconds. YMMV

IIRC my iron is about 430F.  

Sometime back someone suggested placing a paper towel over the board
during ironing. I fold one in half with the board inside. It seems to help.

Keith Bowers WB4LSJ- Thomasville, NC

On 10/19/2013 7:29 AM, kabowers@... wrote:

> You can also "overcook" the transfer process..... With a 2x2 board I iron for about
> 70 seconds, while a 4x6 board requires about 150 seconds. YMMV
>
> IIRC my iron is about 430F.

I mentioned this earlier but one way to take the guess work out of this 
is to measure the board temp with an IR thermometer.  I find that 300F 
works well with PnP and label backing.  I don't think pressure is 
important at all as long as it  is evenly distributed during the 
transfer by moving the iron around.

Preheating the board, and time vs iron temp and heat transfer vs board 
size can all be ignored.  Just scan the board occasionally and stop when 
it gets to 300F or whatever works for you.

I then lay a flat piece of tool steel on top and cool in place.

You can get IR thermometers for less that $20 these days.

Jack K9ACT




-- 


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

       http://schmidling.com

Been using the P1006 for several years now. I use the 1200 dpi setting and turn off the toner save feature. I made a new setup, preferences, Print Task Quit Set, with these setting so I don’t have to remember, also have one set for mirror printing, to get the top and silk layers in PCBExpress.

Registration by running the sheets twice is likely an impossibility. 

A few tricks I learned, 
I have a four roller laminator, 2 before heater, 2 after. I changed the motor so it runs very slow, takes a 4” board over a minute to go thru. adjusted the spring tension as low as it would go and still feed the board, reduced spread. 

I use a temperature of 115 deg. C. actually cycles between 110 and 120, the temp sensor is on the lower roller, takes that long to see a temp. difference when running that slow.

Sand board with random orbital sander, 400 grit, to remove all oxide, and surface blemishes.

Clean board with lacquer thinner, apply very liberally, allow to dry completely, this reforms a thin even oxide layer, this oxide layer gives the toner something better than bare copper to adhere to. Read that they form an oxide layer on the copper to help adhere it to the FRC substrate. This is what allows me to run the laminator at 115 deg. C, instead of the 150 deg. C needed without cleaning with lacquer thinner. 

Make boards about 1/4” larger than needed, toner does not seem to adhere as well next to the edges. 

Don’t tape the art work onto the board, just hold with fingers and feed into laminator. the taped parts don’t transfer well, and the goo is a pain to remove.

I use two or three passes thru the laminator. 

Sand the paper artwork lightly with 100 grit sand paper, after going thru the laminator. Gives the tonner a time to cool and allows the water to penetrate faster, just a few seconds and the paper is translucent.  I use Hammermill Color Laser Gloss Paper. Lowest cost best transfer. Roll the paper off with fingers, very lightly clean bits of paper off with nylon abrasive pad.

I get very repeatable results with traces down to .5 mill for 100 pin smt parts. 

RD