how do you build your prototypes?

[backdrill]

I'd like to know what's your typical way of building your prototypes
after simulating your design or thru breadboad simulation.

How important is the cost to your prototyping work?

What was your experience in dealing with board fab as far as number of
boards is concerned? Do they have a minimum order quantity based on the
panel to be used or they can do a low volume (minimum is a single board)
fabrication? Do they feedback DFM review result?

 

[sky_123]

I don't think most people simulate their entire design using (say) Proteus like many students on edaboard seem to want to do.
I believe most people simulate portions, e.g. at a higher level, or using test data files. Similarly, I would breadboard portions,
but not the entire design. For certain types of circuits you may need to do a lot of physical experimentation (e.g. RF circuits) so there the
breadboarding (not using strip blocks of course) is an important stage.
At some stage, you'll want to move it onto a real PCB, and ordering a single 2-layer or 4-layer board is not so expensive, even for
someone designing something as a hobby. If there are any errors, they can be corrected with a scalpel and bits of wire, but
you should be at a stage where really if you're making more than a few (maybe 2-3) changes on a board, then you were probably not
ready for PCB prototyping. That depends on the complexity of the design of course. Usually I'm confident enough to order a handful
of boards, in case I want to make several copies, for tests, etc.
At low cost the PCB won't be electrically tested, but unless it is a super-complex design, I doubt that is worthwhile doing for a
first prototype.
Since the CAD files are something quite standardised, I've never had a bad experience with a PCB fab company for a prototype, as
long as the CAD files that you supply are correct. But then I tend to stick to 1-2 different companies that I'm used to.
Often they will send you an e-mail if they have any doubts, but don't rely on that.
Also, some people make up 'test board PCBs' occasionally, that are at a pre-prototype stage. The test boards may just have a handful of
components on them, to allow you to get familiar with a portion of the design, e.g. a new processor or DSP chip.