Hi Shawn, I have brought up the same issue with our purchasing guy. It just
strikes me as incredibly screwy. We pay a board house money to build a board
to our specifications. When we find boards that have shorts or opens the
purchasing guy "offers" me the option of electrical testing at increased
cost. So let me see if I have this right - you can charge us extra to make
sure that you did your job right? Funny. We can't charge our customers extra
for equipment that is "right" - they paid for the equipment to be right in
the first place. Somehow the PCB manufacturing industry has developed a
mindset (and the consumers have bought into it) where they just run the
boards through the process and you get what you get. If you want them tested
you pay extra.

We typically find about 1% of the boards we populate end up having some sort
of PCB defect (short or open). The really tough ones to find are the ones
where adjacent traces are shorted, but nothing is visible. However, a little
excavating with an X-acto knife between the adjacent traces and the short
disappears. We can't justify paying extra for electrical testing. So we live
with it. We can't change vendors because our parent company has dictated
that we purchase our boards from some outfit in China. Boards are dirt
cheap - and look really nice. But, we do have the 1% stinkers.

Yeah, I know it would add cost to electrically check the boards. Microwave
ovens, TV's, Cars - It adds cost to almost every product on the planet to
check and make sure it is right before shipping - doesn't it? The difference
seems to be that PCB "customers" will "risk" crappy boards to save a few
pennies (or bucks). Another factor is probably the fact that the average PCB
vendor isn't making a zillion of any particular board. If I was making PCBs
I don't think I could burden the cost of testing every board that went
through.

I suppose ultimately the PCB industry was "given the right" to charge extra
for testing because *most* customers (like the company I work for) refuse to
pay for it. If the PCB houses can't spread the cost of electrical testing
between all customers, then the customers that really want it will have to
pay for it. And the customers that don't pay for it - don't get it.

We (you too) do have the option of investing in equipment to do incoming
electrical inspection on the boards received. But that just pushed the cost
up on each board indirectly didn't it? Fact of the matter is you're going to
pay one way or another.

Choices seem to be...

A. Pay for PCB house to do electrical testing.
B. Do electrical testing yourself & reject bad boards before populating
them.
C. Assume boards are OK, and find the bad ones in final test after the
boards are populated.

(Sigh - Gotta switch to caffeine free soda) Sorry, I kinda got carried
away...

Just get used to it - this seems to be the way things work in the PCB world.

Anyway, I'm still trying sell my boss on the idea of paying me extra for me
to make sure I do my job right.

-- Mark


> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]On Behalf
> Of Shawn Yates
> Sent: Monday, October 03, 2005 12:24 PM
> To: Microcontroller discussion list - Public.
> Subject: [EE]: Board House Quality
>
>
>
> Perhaps this should be under OT instead of EE but...
>
>     Is it me, or is the PCB industry the only industry that seems to
> have given itself the right to make a product, but then charge extra to
> make sure they did it right?  I am referring to the extra charge for
> electrical testing of a bare board.  It just seems wrong.  What if cars
> were made this way.  You could buy a car for X, but for X + Y you can
> buy a car that was tested and they are sure it will run when you turn
> the key.
>
> What's up with that?
>
> Shawn
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
>



-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist