Homebrew PCBs

Slavko,

One thing to check is if there is a change related to the high fusing
temperature.

On paper, try "printing " a blank page so it will go through the printer and
be dried and then print your test image on the same paper the second time.

 

The transparency might have similar issues.

The transparency might be slipping and you could try a backing paper which
might make it better or worse.

 

Finally, try an inkjet since it will not have any temperature issues.

Bertho

 

From: Slavko Kocjancic    Sent: Monday, September 16, 2013 16:15



...so to clean up the problem, and not to argue...

I can make small board with toner transfer metod. Fine traces aren't 
problem.
I can make small board with sensitived board and printed transparency on 
laser Fine traces aren't problem.

... But I have problem with accuarcy. If I draw rectangle 200mm x 200mm 
and then print that and then measure that, the dimennsion is not right. 
With few prints made with same settings I measure the side from 199.5mm 
up to 201.3mm. I tested 3 printers I own, and LaserJet 1018 and 1020 
works identicaly. The Brother HL2030 is little better (from 200mm to 201.1)

So If I pick some big SOIC or TQFP with side of 20mm the error is aprox 
aprox 0.1mm. It's bare visible with naked eye. So no problem with that.

Then I pick some chip in DIL40. The last pin is aprox 0.4mm off the 
hole. If holes are drilled oversized then package should fit, else wil NOT.

Now I have terminal blocks on the edge of board. I have 20 pins stacked 
(200 mils) and in last pin the difference can be 1mm and it's not 
possible to fit that component.

And other thing is that I drill with CNC. And of course if one side of 
board is ok the other is not.

Why the print's isnt consistent I don't know.
For toner transfer (printing on paper) It can be humidity, but when 
printing on plastic transparency I think the humidity can't be problem. 
As image is more distorted in height I assume that it's printer 
mechanics problem.

As I know that my CNC is way under 0.1mm precission It's logical for me 
to try to use it as photoploter.
The process is slower but got accuracy. So If I need accuracy (large 
board) I should go with photoploter style, for small board's the toner 
transfer is better choice...

I know that my english isn't perfect, but think that majority of people 
will understand me. ...ker ne govorim kitajsko.

Slavko.

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