On Tue, 5 Mar 2019 14:24:14 -0500, you wrote: I was stunned by the OSHPARK price and service.
says MADE IN THE USA
and when I pulled the trigger and paid $60 for 3 small circuit boards At $5.00/sq inch you had a 12 sq inch board, so roughly 4 x 3 inches.
they said my order was ready for a fabrication house and I will be
informed when they have added my
3 PCBs to a huge sheet of orders... and
a day later they said? GOOD NEWS...YOUR GERBERS ARE ON THEIR WAY TO A
FAB HOUSE... WE WILL LET YOU KNOW WHEN YOUR
PCBs RETURN FROM THE FAB HOUSE
Yep, exactly how it works. The Chinese board houses do the same kind of combine and send off. Difference is in the volume.
and then
two weeks later? I got my PCBs that I thought OSHPARK was going to make
in the USA.
what makes you think they weren't done in the USA? Had you checked some of the USA fab houses for price? Do that, then start squeezing your wallet to perform CPR.
and then
I spent $13 buying ten PCBs from ALLPCB.com and they were done and
delivered in FIVE days.
Delivery can be a bit more expensive, though. I find DHL to be quickest, and not all that bad a price relative to the other services, although I do not use ALLPCB. Do note that the Chinese board fab houses have a special, say 4.90 for 10 PCBS, dual layer, HASL, etc... max size is 100 cm by 100 cm. Go over that by one cm on the quote, and you'll get an idea of the true price. Then pick ENIG finish and hold on to your wallet. Oshpark is good for smaller boards, not larger ones. Some projects are that small, some aren't. Harvey
Needless to say I will never use OSHPARK again.
On 03/05/2019 01:36 PM, Harvey White wrote:
On Tue, 5 Mar 2019 08:31:05 -0600, you wrote:
Harvey,
? All good info. Thanks.
If I ever come up with a money making idea with a pcb
board involved, I may have to have my boards made, But I don't ever see
that happening. Make sure that you can legally do this with the PC board package you
have. EAGLE and other "free" versions have a "no profit" restriction.
Who knows, maybe in a time saving way if the price was
right, but I need to be realistic as I have many other interests/hobbies
that need some of my time. :) Not that I'd know anything about that...........
That said, when I decide to do something I
go all out to do it the best I can so all this info is great. I am going
to use Muriatic and HP for my etchant for now. I started out many years ago with photoetching, KPR and Kodalith
negatives. Photo stuff was fine, the KPR was nasty stuff.
I tried some presensitized boards, with varying results, negative
density is absolutely critical.
Went to toner transfer, which has been working for a long time. Needed
double sided boards and ended up making each side and epoxying them
together.
However, the designs got so complex that I needed plated through
holes. That ran the limit of what I could do at home.
Tried Oshpark (and they're very nice, good quality, price depends on
the size of the boards), then I tried a Chinese firm, somewhat
different boards, but not too much. Oshpark was ENIG (gold plated),
Chinese is HASL (Hot Air Solder Leveled). Either works.
So I outgrew, if you would, what I could do at home.
Good luck on your projects.
Harvey
Thanks
On 3/4/2019 7:13 PM, Harvey White wrote:
On Mon, 4 Mar 2019 16:43:20 -0600, you wrote:
Ok on the top/bottom posting. Nobody is complaining yet. :)
My default trace setting was 15 and I had bumped it up to 20 so that
sounds good to me. I have seen those "islands" you speak of and figured
it was either a ground plane or a way to save etching time. I may
experiment with that. The island approach really didn't require etching, it needed an xacto
knife and a ruler.
Etching time will be the same, as long as you have enough etchant.
Think about that one, you have to go through the same amount of copper
regardless. When you do the etching, you'll want a bubbler of some
sort. The HCL/H2O2 etchant works very well until you run out of H2O2,
perhaps 30 days. The etchant then changes (slowly) into CuCl etchant,
which etchs when oxygen is added, literally, your first time look at
the copper and you'll see it turning reddish and going away, that's
the copper oxidizing in solution.
Once the etchant changes color, then you're likely in CuCl etching.
I'm not the expert, but an internet search may give you accurate (and
better than mine) details.
For the mechanical approach, you could also use CNC and some sort of
router bit (usually PCB and carbide). It works very well on discrete
transistors/resistors/capacitors but has a limited utility when
dealing with ICs... Has more to do with pin spacing than not.
Main thing is that you make boards that work for you. As you decide
to go from through hole to surface mount, and then to TFQP flatpacks,
and then plated through holes, your techniques will change until you
likely need to use a board house to make the designs. Mine did.
However, there's a lot you can learn in the process.
Harvey
I am using DesignSparkPCB for now.
I ordered the 16oz bottle of MG Liquid Tin. That should last me forever.
Good reasoning on why a lot of people don't use Tinit or Liquid Tin
because they finish soldering all the components right away. Now I can
plan ahead and etch, tin, and save for later finishing if need be.
Thanks
On 3/4/2019 1:45 PM, Harvey White wrote:
On Mon, 4 Mar 2019 11:31:38 -0600, you wrote:
Quick question. Is top posting preferred here. That is the way I like to
do it but on some other forums people complain and like it the other way. I prefer to interleave where reasonable. For this post, I will. For
the previous post, it was so long that without seriously trimming it,
my reply would be at the very bottom.
You get your choice, I think.
Now back to the subject at hand...All good info but, if I am just
starting out and am not worried about trace widths, my job should be
easier if I use wide traces at first, right? I remember taking apart old
electronics and the traces and solder were absolutely thick. And for
starters my projects will be very simple, like a breakout board.
Generally about 16 mils is what I normally use. However, as long as
the traces work for you, and you can build the board, it doesn't
matter.
There's a method that makes the pads as large as possible, so you're
wiring parts between very large pads, islands, even. The 1/16 inch or
so is the space around the pads. Saves etchant and can be done with
an xacto knife in some cases.
I think I seen where Rob found that Krylon enamel paint was a great
resist that could be thinned with lacquer thinner and used in a pen. Depends on how you do the board. I generally did a program (like
EAGLE), toner transfer, and then I tinned the board.
Does Tinit help any or is that just a corrosion preventative and does
anyone use it anymore? It's a bit of a corrosion inhibitor, and is effectively solder, so it
makes soldering easier.
I've done boards both ways, and if you build the board all at once,
then you likely can get away without the tin/lead. What happens if
you don't is that you get tarnish from normal oxidation and soldering
becomes difficult.
If you could mask the pads somehow, you could do a solder mask with
paing, and that would allow you to have a neater board. That, with a
silk screen layer would be a good look.
What they do in the factory is use a solder mask chemical that's UV
cureable... The stencil has holes where the pads are, you coat the
entire board with the mask, let it dry, and then the UV through the
stencil destroys the polymer so that the exposed areas wash off,
uncovering the pads.
Hence the tinning that tends to make the board look good and reduces
corrosion.
Harvey
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