Homebrew PCBs

On Mon, 02 Feb 2004 19:32:44 -0000, Phil <phil1960us@...> wrote:

> well, I've only done a couple of pcbs but I had a similar problem -
> the transfer didn't go that well for bigger areas.  I was pretty
> concerned about it since current capacity is a function of width and
> thickness.  So I just took a sharpie and augumented the resist.
> worked fine.
>

similar problems here too.. but it works for the large pads and 0,5mm 
tracks fine...
(seldom need more)

i guess this is because the laser printer can't print large solid dark 
areas.
i would like to know why (someone?) but if you print a all-black page it 
is worse.

maybe with a newer printer (than my HP IIID) or perhaps a copier it works 
better.
(I think i remember having seen copier output which is really dark on a 
all-black page)

Would be nice to know what influences toner density, i have such a green 
knob
inside my printer which obviously adjusts some high voltage but i don't 
know more.
i guess it is the voltage on the corona wire but....


maybe one could make a "blacker than black" cartridge by increasing the 
distance
of this metal wiper blade in the cartridge, may work...
But then again too much toner and you end up with flattening of thin 
traces.


the bad thing is that it is not uniform, what could be done against that?


ST