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Subject: Re: [Homebrew_PCBs] Custom G10 copper clad

From: Stefan Trethan <stefan_trethan@...>
Date: 2016-03-18

You can buy pre-sensitized boards or apply your own photoresist, as a liquid varnish or film.

Most people are going to look at you as if you are crazy for wanting a specific colour and weave of material. That is because you are crazy of course, and nothing to worry about.

It will not help your quest at all, but consider buying double sided laminate (with copper on both sides). I found it much easier to obtain and just etch one side away completely for single sided boards. Of course it makes impossible to see the inside.

Also mind that in any case the copper on the other side will severely change the colour you see, even if the seller provides a photo of the board side. The copper layer is actually a dark red underneath, completely different colour from the shiny top surface.

ST

On Fri, Mar 18, 2016 at 5:13 PM, 'Brad' unclefalter@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:


With photoresist though, the boards have to be bought pre-sensitized right?

 

Here is an example of the artwork Radio Electronics offered in their construction kit for those who were going full DIY:

 

http://www.swtpc.com/mholley/TV_Typewriter/page_18.pdf

 

Will laser really make a difference?

 

I’m looking at another company that sells already made natural coloured copper clad: http://www.currentcomposites.com/html/electrical_grade_laminates.html

 

The thing that I find confusing is some companies seem to use FR4/G10 interchangeably, even though they mean two different things..

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
Sent: Thursday, March 17, 2016 8:55 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Custom G10 copper clad

 

 

On Thu, 17 Mar 2016 16:32:34 +0100, you wrote:



>Are those boards gold plated or something???
>
>$400.00 sure that'snot a typo???

I think what they're doing is taking G10 and laminating the copper
directly on it, a one-of custom job.

That's for bare boards, not even made and drilled. I think he's going
to have to make those boards himself. I'd be tempted to do
photoresist and the original negatives ∗if∗ I had the process down and
working to my satisfaction.

Toner transfer may or may not give the same look and feel, although
that could be debated.

What I would certainly do is make at least one with conventional FR4
just to see what it looked like. It probably will not be exact, but
it would be a good test of the design.

Then I'd start working on the boards. If I remember it properly, the
average board was 0.062 in thickness, with some of the backplanes
being about .125 or so. It depended on what was attached to them and
how much flexing was tolerable.

I've got board stock from that era, but most of it is about 4 by 5 or
so, and I have no idea if it's G10 or not. Likely it's FR2 or 3. How
might I tell? If I had the stock in the right size, I'd be happy to
give you some (for postage).

Harvey

>
>cb
>On 3/17/2016 3:57:52 PM, Stefan Trethan stefan_trethan@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:
> 
>I didn't follow the conversation before, but $400 for a couple pieces regular FR4 seems pretty crazy to me.
>
>
>ST
>
>
>
>On Thu, Mar 17, 2016 at 3:05 AM, 'Brad' unclefalter@... [mailto:unclefalter@...] [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]> wrote:
>
>
>
>Hey guys,
>Some of you might remember my queries about trying to get ‘correct’ looking single side copper clad PCBs for my vintage TV Typewriter project. I think I may have found a source, and I wanted your opinions to make sure I’m getting the right thing and can do what I want to do.
>The company I found is American Micro: http://www.americanmicroinc.com/g10-fr4/ [http://www.americanmicroinc.com/g10-fr4/]
>According to Don Lancaster, he used ‘G10 Green’ boards. The above appears to be more or less that. Then what AM will do is add the copper cladding. It will cost me $400.00USD to yield the following:
>2 pcs – 9”x7”
>6 pcs – 5”x7”
>Plus remainder from sheet after cutting.
>Now, they are specifying .010” .. I’ve no idea what thickness the original TVT boards were, but I’m guessing they were probably thicker (.06ish?). Thoughts?
>I think the price is higher than what those pieces would cost via suppliers on ebay, etc. However I’m not bothered by that – the important thing for this project is that the boards look correct and have the correct grain and colour. In searching various single side PCB suppliers, the colours are too fancy or modern and the grain doesn’t look right.
>For a refresher, here’s a shot of one of the original boards: http://i1381.photobucket.com/albums/ah216/unclefalter/tvtboards2_zpssy81hx8b.jpg~original [http://i1381.photobucket.com/albums/ah216/unclefalter/tvtboards2_zpssy81hx8b.jpg~original]
>What do you guys think? Also, is there anything I need to be wary of in the process that they use to affix the copper cladding to the boards? I’m hoping to use the toner method of etching to get these done.
>Thanks again!
>
>Brad
>
>