Homebrew PCBs

I think that in order to do 3 oz one must use semi-additive etching.
that is put doen the photoresist and then electrroplate, strip the resist
and etch the whole board.

On Mon, Dec 7, 2009 at 09:56, Kerry Wentworth
<kwentworth@...>wrote:

>
>
> christiansen_alex@... <christiansen_alex%40hotmail.com> wrote:
> > --- In Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>,
> "leon Heller" <leon355@...> wrote:
> >
> >> ----- Original Message -----
> >> From: "Simao Cardoso" <simaocardoso@...>
> >> To: <Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>>
> >> Sent: Sunday, December 06, 2009 9:30 PM
> >> Subject: Re: [Homebrew_PCBs] 105 u copper needed
> >>
> >>
> >>
> >>> Simao Cardoso wrote:
> >>>
> >>>
> >>>> known as 3 oz/in²
> >>>>
> >>> What a mistake, I may dislike imperial units but this was, how to say,
> a
> >>> shoot in the _foot_? :>
> >>>
> >> Etching would take a very long time with 3 oz/sq. inch copper. I make it
>
> >> about 1.5 mm thick. 8-)
> >>
> >> Leon
> >>
> >>
> > thanks all for intersting reply :)
> > and Leon ,yes I know its not easy to get..that's why I asked here,as I
> have noticed that much can happen here in this group :)
> >
> > If I get it..it might be a problem with etching.. or scould it not be the
> same ..except the time.
> > I dont understand the last line "I make it about 1.5mm thick 8) ??
> > ,maybe not important ,but if it is.. please tell me again..
> > alex
> >
>
> Copper is measured in ounces per square foot, not per square inch. 3
> ounces per square inch would be 15 mm thick (not 1.5) and a 12 inch
> square board would weigh 27 pounds, or about 12 kilos. He was being funny.
>
> Kerry
>
>  
>


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