--- In
Homebrew_PCBs@yahoogroups.com, "a3v03v0" <a3v03v0@...> wrote:
>
> I would guess that you are aware of these, but in case you are not.
>
> Pulsar's paper is coated with starch and will not pull properly attached
> toner from a PCB. The starch dissolves allowing the paper to float away
> from the PCB.
>
> Pulsar has a foil the will help bridge pinholes in the toner. It does
> not bridge missing toner.
>
> The pulsar site also has/had a page on etching the pcb using a sponge.
> The mechanical action greatly reduces the etching time. It uses Ferric
> Chloride so a vent hood is a must.
>
> Daniel Johnson
Yes thanks - I got all the Pulsar stuff recently and have
finished etching 2 boards using the starch paper and the
Green laminating paper. Also I got the pulsar-recommended
laminator which is amazing, I should have tried it sooner.
The results so far look much better esp. using the
Green plastic, the resulting copper is very solid, no
pock marks. Though the edges are quite jagged.
I am using HCl + H2O2 etchant and have so far not tried
the sponge method. My etch times are definitely too slow
considering these are very small boards.
>
> --- In Homebrew_PCBs@yahoogroups.com, "jc805sb" <jc805sb@> wrote:
> >
> > --- In Homebrew_PCBs@yahoogroups.com, "javaguy11111" javaguy11111@
> wrote:
> > >
> > > Are you trying to mount MEMs devices on a pcb or using a pcb for
> making MEMs devices?
> > >
> >
> > I am etching copper patterns which operate as the MEMS
> > (the field calls it MEMS although there's nothing mechanical).
> > I have pictures on my blog here,
> > http://88proof.com/synthetic_biology/blog/archives/280
> >
> > The pictures show pretty poor etch results which
> > I am trying to improve using the best SMT techniques first.
> > Pad size/spacing is 1mm x 1mm with 0.125mm gap, or smaller!
> >
> > Other researchers in the field have made similar MEMS
> > on flexi boards. I can list some interesting articles
> > if interested. These boards move liquid droplets across
> > surfaces (even vertical surfaces). Though this requires
> > maybe >+1000V.
> >
> > Something tangentially interesting, some researchers used
> > an "aborted etch" method with multiple dips in etch and
> > multiple mask steps, to make copper traces of different
> > heights. Not useful for standard PCB however they were
> > able to use it as MEMS for nanoparticle separation.
> > They used ferric chloride as the etchant and found it
> > to be a linear etch, so the copper "steps" could be
> > precisely made. These steps were 10um to 50um or
> > something.
> >
> >
> >
> > >
> > > --- In Homebrew_PCBs@yahoogroups.com, "jc805sb" <jc805sb@> wrote:
> > > >
> > > >
> > > > I am etching general pcb's and also etching pcb's
> > > > for MEMS devices. The MEMS uses copper pads as small as
> > > > possible so I am attempting to get down to 0.125mm (0.005")
> > > > and am trying the laminator+toner transfer with treated
> > > > paper and "GreenTRF" process. Others do this for SMT
> > > > according to online sources so I am hopeful it will work.
> > > >
> > >
> >
>