Homebrew PCBs

Hello everyone..  forgive me for being so clueless.  i do some 
electronics work related to microcontrollers, embedded systems, and 
robitcs.  I've only done a few circuit boards myself and I barely 
know the basics.  I imagine that there's a lot more to know.  I was 
wondering how high the quality of the boards you people make are?  
Are you producing boards that are on a commercial level?  Something 
people would buy?  I'm reading some of the messages here.  I 
apoligize if this is a stupid question but I just wanted to find that 
out.  I have to run but i plan on stopping by again to read and learn 
a lot.  Thankks..

----- Original Message ----- 

From: "John" <DiamondDyn@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, December 30, 2004 9:32 PM
Subject: [Homebrew_PCBs] Curious


>
>
> Hello everyone..  forgive me for being so clueless.  i do some
> electronics work related to microcontrollers, embedded systems, and
> robitcs.  I've only done a few circuit boards myself and I barely
> know the basics.  I imagine that there's a lot more to know.  I was
> wondering how high the quality of the boards you people make are?
> Are you producing boards that are on a commercial level?  Something
> people would buy?  I'm reading some of the messages here.  I
> apoligize if this is a stupid question but I just wanted to find that
> out.  I have to run but i plan on stopping by again to read and learn
> a lot.  Thankks..

I've sold several of my home-made boards, mainly for working prototypes of 
systems I've designed for clients. They've always been single-sided up to 
now. I use conventional UV exposure with pre-coated material, and 1:1 
artwork produced on a laser printer. They might not be very pretty but 
people like being able to get something very quickly that they can evaluate. 
I generally work to 12/12 mil design rules for my home-made PCBs, going down 
to 10 mils if things get tight. The commercial boards that I have made by 
PCB-Pool (double-sided PTH and four-layer) typically use 8/8 design rules 
and 0.3 mm holes. PCB-Pool can go down to 6/6, but I haven't needed that 
yet.

Leon 



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--- In Homebrew_PCBs@yahoogroups.com, "John" <DiamondDyn@a...> wrote:
> 
> Hello everyone..  forgive me for being so clueless.  i do some 
> electronics work related to microcontrollers, embedded systems, and 
> robitcs.  I've only done a few circuit boards myself and I barely 
> know the basics.  I imagine that there's a lot more to know.  I was 
> wondering how high the quality of the boards you people make are?  
> Are you producing boards that are on a commercial level?  Something 
> people would buy? 

Isn't this a great list? I can say that without being immodest even
though I'm the listowner, because the list is made by the people on it.

Take a look in the Files, under Photoetching and Ben Lanmon, here's a
TinyURL link:
http://tinyurl.com/6bykb

Also take a look in Photos. They run the gamut from good enough to
work, to darn close to commercial quality.

Steve Greenfield

--- In Homebrew_PCBs@yahoogroups.com, "Steve" <alienrelics@y...> 
wrote:
> 
> --- In Homebrew_PCBs@yahoogroups.com, "John" <DiamondDyn@a...> 
wrote:
> > 
> > Hello everyone..  forgive me for being so clueless.  i do some 
> > electronics work related to microcontrollers, embedded systems, 
and 
> > robitcs.  I've only done a few circuit boards myself and I 
barely 
> > know the basics.  I imagine that there's a lot more to know.  I 
was 
> > wondering how high the quality of the boards you people make 
are?  
> > Are you producing boards that are on a commercial level?  
Something 
> > people would buy? 
> 
> Isn't this a great list? I can say that without being immodest even
> though I'm the listowner, because the list is made by the people 
on it.
> 
> Take a look in the Files, under Photoetching and Ben Lanmon, 
here's a
> TinyURL link:
> http://tinyurl.com/6bykb
> 
> Also take a look in Photos. They run the gamut from good enough to
> work, to darn close to commercial quality.
> 
> Steve Greenfield

  With all respect Steve, the photo's there are quite far away 
from "commercial quality" as you named it. The problems begun when 
you need 100 similar boards with metalised through holes and able to 
be populate with just 0603 or 0805 series (and last one is huge!).
With a high component density and other than 100 mil DIP packages or 
50mil distance between pin to pin of SMD components. The other 
problem is the silk screen if needs less (or equal) of 10 mil 
resolution. Not the last one is the isolating varnish and thermal 
and mechanical resistange of this.
And a huge problem is when you need for instance a 15x15 inch board 
(or any other bigger dimension where the printing error will affect 
seriously the board quality).
  Prototyping yes. Very small series yes. But production never.

best regards,
Vasile
http://surducan.netfirms.com

On Tue, 04 Jan 2005 10:45:56 -0000, Vasile Surducan <vasile@...-cj.ro>  
wrote:

>
>   With all respect Steve, the photo's there are quite far away
> from "commercial quality" as you named it. The problems begun when
> you need 100 similar boards with metalised through holes and able to
> be populate with just 0603 or 0805 series (and last one is huge!).
> With a high component density and other than 100 mil DIP packages or
> 50mil distance between pin to pin of SMD components. The other
> problem is the silk screen if needs less (or equal) of 10 mil
> resolution. Not the last one is the isolating varnish and thermal
> and mechanical resistange of this.
> And a huge problem is when you need for instance a 15x15 inch board
> (or any other bigger dimension where the printing error will affect
> seriously the board quality).
>   Prototyping yes. Very small series yes. But production never.
> best regards,
> Vasile
> http://surducan.netfirms.com


Vasile, production is not interesting because it wouldn't be cheaper at  
all.

As for the quality discussion, let me explain it differently:
If you look at homebrew beer, do you believe one can make a beer that is  
as good as commercial bear? Given enough time and devotion? The same is  
true for PCBs.
The more money and effort you put in the better the boards will be.
There are members here who make multilayer boards, with throughhole  
plating. that is as  good as it gets commercially. (add photo-sensitive  
soldermask). At least one uses a inkjet so printing distortion isn't an  
issue.
Those people make great boards, for sure, but their setup is very  
expensive too. Nowadays you get a commercial board for 10 bucks or so, but  
that isn't why they are making the boards, they do it because the want to  
make that prototype _today_.

Now, as said a multilayer - throughhole plating setup is very, very  
expensive. If you can live with 2 layers and no plating it gets very, very  
cheap (below 10 bucks equipment cost).
I can live without throughhole plating and multilayer, because i get a  
board in under an hour and for less than 1$ in exchange. I make component  
legend as good as a commercial board, but i don't do soldermask simply  
because i don't need it and don't want to make a photo-process setup again.

So, you see, commercial quality isn't a question of possibility, just a  
question of what you want to spend for it. At some point it gets  
economically not viable and the only reason you have for making you own is  
very, very short time until you have the board in hands.

ST

John,
      I sold bare boards that were milled not etched for over a year.
People don't mind a board that is not perfect as long as it works.
After you get rolling then have a batch made.

                                         John


--- In Homebrew_PCBs@yahoogroups.com, "John" <DiamondDyn@a...> wrote:

> 
> Hello everyone..  forgive me for being so clueless.  i do some 
> electronics work related to microcontrollers, embedded systems, and 
> robitcs.  I've only done a few circuit boards myself and I barely 
> know the basics.  I imagine that there's a lot more to know.  I was 
> wondering how high the quality of the boards you people make are?  
> Are you producing boards that are on a commercial level?  Something 
> people would buy?  I'm reading some of the messages here.  I 
> apoligize if this is a stupid question but I just wanted to find that 
> out.  I have to run but i plan on stopping by again to read and learn 
> a lot.  Thankks..

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@g...> wrote:
> 
> On Tue, 04 Jan 2005 10:45:56 -0000, Vasile Surducan <vasile@s...>  
> wrote:
> 
> >
> >   With all respect Steve, the photo's there are quite far away
> > from "commercial quality" as you named it. The problems begun 
when
> > you need 100 similar boards with metalised through holes and 
able to
> > be populate with just 0603 or 0805 series (and last one is 
huge!).
> > With a high component density and other than 100 mil DIP 
packages or
> > 50mil distance between pin to pin of SMD components. The other
> > problem is the silk screen if needs less (or equal) of 10 mil
> > resolution. Not the last one is the isolating varnish and thermal
> > and mechanical resistange of this.
> > And a huge problem is when you need for instance a 15x15 inch 
board
> > (or any other bigger dimension where the printing error will 
affect
> > seriously the board quality).
> >   Prototyping yes. Very small series yes. But production never.
> > best regards,
> > Vasile
> > http://surducan.netfirms.com
> 
> 
> Vasile, production is not interesting because it wouldn't be 
cheaper at  
> all.
> 
> As for the quality discussion, let me explain it differently:
> If you look at homebrew beer, do you believe one can make a beer 
that is  
> as good as commercial bear? Given enough time and devotion? 

 Hi Stefan, of course homebrew beer is alltimes better than 
commercial !

>The same is  true for PCBs.

 Yess, agree, if you have 20'th, good eyes and you don't produce PCB 
in this way for living purposes.
 But don't forget, 20 flies away, glases on the nose come quickly 
and beautiful girls are good just to look at.

:)


> The more money and effort you put in the better the boards will be.
> There are members here who make multilayer boards, with 
throughhole  
> plating. that is as  good as it gets commercially. (add photo-
sensitive  
> soldermask). At least one uses a inkjet so printing distortion 
isn't an  
> issue.
> Those people make great boards, for sure, but their setup is very  
> expensive too. Nowadays you get a commercial board for 10 bucks or 
so, but  
> that isn't why they are making the boards, they do it because the 
want to  
> make that prototype _today_.
> 
> Now, as said a multilayer - throughhole plating setup is very, 
very  
> expensive. If you can live with 2 layers and no plating it gets 
very, very  
> cheap (below 10 bucks equipment cost).

 For this reason I'm staying on two layers even for production 
boards.



> I can live without throughhole plating and multilayer, because i 
get a  
> board in under an hour and for less than 1$ in exchange. I make 
component  
> legend as good as a commercial board, but i don't do soldermask 
simply  
> because i don't need it and don't want to make a photo-process 
setup again.
> 
> So, you see, commercial quality isn't a question of possibility, 
just a  
> question of what you want to spend for it. At some point it gets  
> economically not viable and the only reason you have for making 
you own is  
> very, very short time until you have the board in hands.
> 

 Now, be honest, how many boards produced in the indicated manner 
looks EXACTLY the same? How many problems do you have when are 
mounting SMD devices on those boards? Show me please a picture with 
your highest desity PCB board, homebrewed.

best regards,
Vasile

On Thu, 06 Jan 2005 13:42:01 -0000, Vasile Surducan <vasile@...-cj.ro>  
wrote:

>
>  Now, be honest, how many boards produced in the indicated manner
> looks EXACTLY the same? How many problems do you have when are
> mounting SMD devices on those boards? Show me please a picture with
> your highest desity PCB board, homebrewed.
> best regards,
> Vasile


The question is not if they look the same, but could they look the same.
If top quality is your goal you must optimize your process for it, i  
didn't, i wanted a cheap and fast process with OK quality.

Also, maximum component density is not something i optimize for, there are  
practical reasons to have lower component density than possible with the  
process.

I don't have a digital camera but i can show you the layout of a board i  
made.
<http://trethan.at.tf/pub/esr.gif>
it is about the highest component density i'm willing to use.
You see it has DIL ICs, but this is because i had them in stock and  
actually the component density is higher if you use a single sided board.  
(because the DILs are at the "unused" side).
I'm sorry i can't provide a scan of the finished board but it is mounted  
inside a meter and i'm not willing to take it out (it is glued in).

For my first board using compoent legend on copper artwork sucessfully  
look at
<http://trethan.at.tf/pub/comp_bot.jpg>.


Ha, found a scan of the ESR meter board you saw the layout above:
<http://trethan.at.tf/esr_bot.jpg>
You see, the legend went wrong, it was the first try, look at the URL  
above to see how it should be done.
The fault with the legend was apparently why i scanned it.

If you look at the top <http://trethan.at.tf/esr_top.jpg> you will see a  
certain offset in the component legend, another flaw i worked out already.  
You need to mess up a few beers before they are good.

A board i sell:
<http://trethan.at.tf/pub/milliohm/top.jpg>
<http://trethan.at.tf/pub/milliohm/bot.jpg>
<http://trethan.at.tf/pub/milliohm/external.gif>

You see, not top quality, why? It was requested not to use SMD and to make  
it big enough for novices to solder.
The customers wanted a cheap PCB they can easily assemble.

I am very limited with what i can do because i use a ancient LJ IIID  
(300dpi). this makes use of fine pitch SMD very hard, but i'm working on  
getting a new printer.

Homebrew beer. As good as you want it.

ST