Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

----- Original Message -----
From: "Adam Seychell" <adam_seychell@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, June 30, 2003 4:17 AM
Subject: Re: [Homebrew_PCBs] Re: Inkjet Transparencies


>
>
> Ted Inoue wrote:
> > I would think the most productive thing would be to keep a record of
> > all the printers and media that work or don't work. In this way, a
> > newcomer can simply refer to a chart and have an easy time learning
> > from the combined experience of those in the group.
> >
>
> That would be a extremely useful reference to use. I was planning
> on making a web page dedicated to this very topic, but hadn't had
> the time. Ideally some form of measurements would need to be
> taken so all the different printing tests can be accurately
> characterized. Some measurements that come to mind are; overall
> relative light transmittance and line edge jaggedness (or maximum
> deviation of ink droplets from an ideal line). I have a
> microscope that can take pictures of line edge jaggedness.
> The latter is responsible for the minimum PCB line widths that
> can be achieved.

Many years ago I worked on subjective copy quality for Xerox Research (UK),
correlating it with physical measurements. IIRC the main physical parameters
used were 'edge gradient' and 'line darkness', measured automatically with a
very expensive piece of equipment. Line darkness is basically your relative
light transmittance and edge gradient probably isn;t relevant with ink jet
technology using transparency material. I think you would need a statistical
measure of the 'jaggedness'.

Leon
--
Leon Heller, G1HSM
leon_heller@...
http://www.geocities.com/leon_heller