[sdiy] My PCB positives are see through!

[Rutger Vlek]

Dear Maarten,

i had some very good results with special transparants for inktjet printers 
printed on my home HP Inkjet printer on highest quality from Eagle PCB 
designer. The UV exposure time i used is about 1,5 to 2 minutes with a face 
tanner (4 UV tubes) from a distance of 30 cm. The only thing you really need 
to be carefull with is that you don't touch the ink when it's still wet and 
that no dust comes on the transparents.

Greetings,

Rutger


>From: "Maarten Halmans" <halmans at home.nl>
>To: "sdiy" <synth-diy at dropmix.xs4all.nl>
>Subject: Re: [sdiy] My PCB positives are see through!
>Date: Wed, 14 Dec 2005 10:06:04 +0100
>
>A few years back I also had better results with printing or photocopying on 
>transparancies. At that time you could feel the toner on the sheets. 
>Nowadays new printers and copiers use less toner, my guess it is  because 
>it is cheaper and toner cartridge last longer, maybe it's also an 
>environmental thing. Some tricks help to get somewhat better results with 
>the new stuff. Rotating the image so that the smallest side corresponds 
>with the smallest side of the paper helps. In several board designing 
>programs you can select the fill style for the polygon planes. Use stripes 
>or crosses instead  of a solid fill style.
>If you print on plastic sheets it's also possible to "wash" them with black 
>ink. Just use a piece of cotton wool and gently rub the ink over the sheet. 
>Most ink will stick to the toner and it will fill the tiny holes. Remove 
>the redundant ink with clean cottons. I stopped with the plastic sheets 
>because they tend to deform a little because of the heat of the fuser. This 
>becomes a problem when using double side design especially when on one side 
>there is a power plane. Nowadays I use calques with good results.
>
>>I guess it's possible that this isn't a big deal, but I just got my
>>prints back on transparancies for etching a few boards and, despite
>>having them done at high quality, I can see right through the ground
>>plane when I hold it up to any light.  The traces themselves look alot
>>better, but I'm still a bit un-nerved about this.  I called the
>>printers and they've assured me this is normal for anything that uses
>>toner and the only real option for better quality is to use a press
>>(big money).  I'd rather not try to stack multiple copies on top of
>>one another (even with 3 I can still see through them a bit) as
>>aligning them will be a pain.  Comments?
>>
>