Homebrew_PCBs

I was just browsing the pre sensitized boards at Circuit Specialists
(http://www.web-tronics.com/printed-circuit-board-supplies.html) and
noticed their non MG double sided boards are priced much lower than
the MG 600 boards.

Is there a compelling reason to opt for the MG boards over the non-
MG boards? Also is there functional difference in the MG positive
develoer and the unbranded positive developer they sell?

Thanks for any comments.

Art

> I was just browsing the pre sensitized boards at
> Circuit Specialists
>

(http://www.web-tronics.com/printed-circuit-board-supplies.html)

> and
> noticed their non MG double sided boards are priced
> much lower than
> the MG 600 boards.
>
> Is there a compelling reason to opt for the MG
> boards over the non-
> MG boards? Also is there functional difference in
> the MG positive
> develoer and the unbranded positive developer they
> sell?
>
> Thanks for any comments.
>
> Art
>

I'm guessing its a quality control issue with the base
laminate. The MG material apparently meets some
additional standards that the other material does not.
Its probably fine for prototyping, but then again, one
would sure hate to run into moisture absorbtion or
contamination issues. I've had trouble in the past
with marginal laminate, eg leakage currents, and
oscillator drift due to a poor laminates dielectric
stability. I guess a lot depends on what type of
circuitry your builiding.

I get my laminate from Tom Berryhill, either CEM or
FR4 depending on what I need. Its high quality
material and I think he applies the photosensitive
material just prior to shipping, so I don't have shelf
life issues, unlike way too many other outfits who let
it sit on the shelf for too long. His prices are real
competitive, but then again, I use negative acting
resist, positive might be more, not sure.

I'll see if I can get a hold of Tom, I'm sure he could
shed some light on the differences between industry
standard and the MG as well, having been in the
business. Same deal with the chemistry.

Ron



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> Is there a compelling reason to opt for the MG boards over the non-
> MG boards? Also is there functional difference in the MG positive
> develoer and the unbranded positive developer they sell?

I use the MG Chemical series 600 boards. Have very good results
with them. I have seen the other boards they sell but have never
tried them out. I do know I like the MG Chemical board better than
some other brand I tried back a long time ago, don't remember the
name don't think they are around anymore. Also the MG Chemicals
boards are much more convinent and consistent than trying to use the
spray on type resist.

Ben