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On 09/16/2013 11:14 PM, ctech wrote:
So what I do now is dry the paper in an oven then print the mask and dry it again every time I use them. BTW humidity is generally over 80% here all the timeSlavlo: regarding your print dimensions,..I had a very simliar problem, printed copper and solder mask, etched the board and and then the solder mask did not line up anymore, had up to 3mm on 200mm deviations. And it turned out to be the humidity, makes the paper shrink and expand. Anywho a quick test you can do is draw/print marks on the paper heat it up in the oven for 10 minutes ~80C and measure again
On Mon, Sep 16, 2013 at 2:15 PM, Slavko Kocjancic <eslavko@...> wrote:
...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.