Hi Anne!


>Thanks Myke -
>   I have your "Handbook of Microcontrollers", and have to tell you it's
>what's getting me through this project. I'm a software engineer, more
>at home with AWT than with hardware, but on this project I'm chief cook
>and bottle washer.  Your book helped on my last contract as well, when
>I suddenly had to start programming the 8051.

I'm glad to hear you like the book and got useful information on it.

>Thanks for the essay on quality & contract manufacture. This is the
>first thing I've ever had made, so I'm learning as I go.
>
>My production run is 2000, with several more 2k runs possible if these
>sell well. So I can't justify lots of money for testing.
>Basicly I can test every component in the board by a couple simple tests.
>If something doesn't work, it seems far simpler to let a human figure out
why not.
>Especially since, for this volume, if I get more than a few bad boards
>it's probably some process related event - e.g. "that component can't stand
the
>reflow"

You should *never* hear something like that from a board stuffer - or if you
do, ask them for a part that they guarantee that will survive the reflow
process.  The design and part selection has to be agreed to by all parties
for the best quality of the finished product.

>I guess what I don't understand is the role of testing & rework in
manufacturing.

You should find a manufacturer that is ISO9000 certified (I should have
mentioned this last night) and look at their ISO Plan for how they handle
defective product.  Ideally, they should have a returns process as well as a
quality improvement process to ensure the defect doesn't happen again.  If
it doesn't, then find one that has a returns process.

There are a ton of low-cost manufacturers that are ISO9000 certified - so
this really isn't something that defines a low-cost versus a high-cost
manufacturer.

>Isn't there some minimum board complexity below which it's cheaper to throw
out
>the bad boards than to rework them?

That's a calculation that you will have to make based on the expected
fallout and cost of repairs.

>> Admittedly, your design is probably a lot more complex, but spending time
>> coming up with a good debug process will help the card stuffer build a
>> better product, reduce his costs (which are ultimately yours) and
increase
>> your customer's satisfaction.
>>
>no, my product's only marginally more complicated than that. I have a PIC,
>a bucket-brigade sound chip, and an audio amp, and support circuitry.
>
>Thanks again for the essay. I feel a lot more confident talking to
manufacturers
>about testing now.

No problem - good luck and let us know how you make out,

myke