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

On Fri, 18 Mar 2016 09:03:23 -0700, you wrote:


Hit return too quickly.

>So yeah, the reason I went to these guys is, it looks like we have the right ‘grain’ and right colour. I don’t care so much about fire resistance, but it seems like all the G10 I’ve found in my color is FR4 regardless.

All the G10 is likely FR4, I don't see a real difference in color or
grain.

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>When you guys were doing these boards in the 70s.. they were single side copper clad photo sensitive right? I tried asking Don exactly what format the boards he used came in (ie if they were just the PCB or had copper affixed), but he tends to be cryptic in his responses.

Single or double side, optionally photosensitive.

The people who were making the board material could laminate the
boards with copper foil, but you never bought the bare fiberglass
unless you staked in terminals and wired that way.

His boards were likely silk screened (common in the 60's and 70's for
relatively non-complicated boards). Toner transfer would give you an
equivalent look.

Photoetched was a complicated process, more commercial than not, and
may not have been all that prevalent in the hobby side. I did it, but
I had access to the chemicals, a view camera and the darkroom needed.
Toner transfer was not possible (no laser printers, depending up to
when, that you could have yourself). Copy centers, businesses,
likely, but not home use.

Harvey


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>From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
>Sent: Thursday, March 17, 2016 12:03 PM
>To: Homebrew_PCBs@yahoogroups.com
>Subject: [Homebrew_PCBs] Re: Custom G10 copper clad
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>Hi guys,
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>I have been following this group for many months, and I am very excited to see the quality of the discussions presented here.
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>I have not contributed until now because I had little to add. I made boards as a teenager in the '60s and then into the '70s. In those days I used G-10 board. A some point FR-4 crept in, and became the standard for PWBs. Recently, I have become interested in making boards again, and am delighted to have discovered this group.
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>My 2 cents: I think the train has become derailed on the subject for G-10 vs. FR-4. It seems to me that the stated goal was to get boards that look like Don Lancaster's green G-10. There are several companies making unclad G-10 and FR-4. You only need to look at the websites to see that both are the same color when purchased as natural. The only difference between them is the addition of a small amount of Bromine to make
>the FR-4 boards flame retardant. Check this out: http://www.acculam.com/data-chart.html. Other places on this website (Accurate Plastics, inc) show samples of the material, and it can be seen that the color is the same. The color of the G-10 from American Micro Industries is the same.
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>The "green" color is called natural. Back in those days, the only color that glass/epoxy boards came in was natural or "green." The shade did vary between manufacturers, probably because of differences in the epoxies they used.
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>Since the color is the same and the goal is to provide the same looking boards, I think that the solution is to use FR-4, and specify "natural" color for the base material.
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>(Another) Harvey
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