← Back to team overview

kicad-developers team mailing list archive

Re: Re: What is scale adjust in plot for?


On Fri, 26 Jun 2009, Lorenzo wrote:

Said that, I found that most laser toner today are not opaque enough and paper transport isn't
exactly linear in printers (traction is 'wavvy'). I won't recommend doing <25 mil work on home
printers :P

Going a bit OT here, but anyway... For one layer UV-mask one should use full green from inkjet (cyan and yellow). Some experimentation for ink brand may be needed (try searching web first ;). I've seen 5 mils stuff done that way. Stuff that is opaque to UV is not necessarily opaque to VIS range.

For toner transfer the largest error comes from paper shrinkage during hot lamination step. That may be about half to one percent or so. Drying the peper before printing is of help as is low work area humidity. If wave amplitude is low enough and has not a cumulative efect, it's possible to stay in tolerances I think ;P. The old LaserJet 4000 TN does fine for TSSOP and, while not exactly home printer is cheap enough :). Newer colour HP at ¤JOB is more than good enough, 6 mils works too. It might be priced around 2 k¤ or so though. Proper temperature control for the transfer step is also a must, as is enough pressure and cooling. Old GBC four roll (hot + cold rolls) laminators are great, but home made one is good enough most of the time. While shopping, try to find one with magical L-405 (hyphen may be elsewhere too) on it. Various brands with those numbers have a good design and are cheap. Pic of the guts here:


One has to make temperature control for it and PD-controller with P(D/W)M power stage is easily made around a dual opamp. Oh, I should probably put that on the Wiki...