this has been kicked around a lot and i do not at all dispute what you
have said here

nevertheless, we frequently seem to have requirements that the bd house
could not appreciate

e.g., sometimes a part hangs significantly  over a board edge (the
features of which may not be apparent to a board house) and a clever
arrangement of the panel can allow the part to hang into the right
adjacent area of an adjacent bd thus saving hand solder steps

sometimes wastage of material is more than offset by assembly savings
due the arrangement of the boards and the dimensions of throw away rails
vs. what they offer

clearly, however, the pitfalls of doing it yourself are real

i think the best compromise on this topic that i have seen is mike

draw all the details of the panel, breakaways and such and then include
only one instance of the bd and explain what it is that you want
this more or less allows you to have your cake and eat it too
no DRC issues, no objects missed in copy and paste (got burned on that
once), time offloaded to the board house

(this method however doesn't address the best utilization of their raw
material size and tank sizes)

in general i don't think there is a hard cost for the fab shop's
panelization efforts (since they do it anyway), it is more or less
overhead depending on your relationship and size of order, etc.
so having said that i agree that their time is 'free' and may save in
other ways also

over the years (and even lately) having dealt with maybe 40 or more
board shops i have seen more than once the following amusing relevant
quotation quirk:
i panelize several different boards, sometimes just dumb shear aparts
(we have a shear), the appearance is one board, one rectangle

the shops calls and says "i see you have several part numbers here" (by
looking at the nomenclature on the board)
then they try to angle for more money ...
it's as if they feel burned for the setups they didn't get
guess who i don't call back

another one
we make a nice multi-up panel of say 6 of the same bd, maybe rails
around the perimeter and tab routing and all kinds of crap that unify it
into a single deliverable 'thing'

the bd is to be delivered as presented, i.e., we break it apart AFTER
assembly so from our viewpoint it is ONE bd
what follows all too often is endless confusion over how many bds we
want, they often want to count the individual ones to get the price up
i ordered 24 pcs, i got 4 bds
i have taken to the rather lengthy:

'4 pcs ea of 'our panel' (their panel is different!, got burned on that
too) which consists of 6 bds per each of 'our panel'
after a few phone calls about how many that really means that usually
does the trick

Dennis Saputelli

Andrew Jenkins wrote:
> On 04:04 PM 4/11/2002 -0400, [EMAIL PROTECTED] wrote:
> >Tim,
> >In my opinion, I would not do the panelization in any of them. I let the Fab
> >house do ... it.
> I agree. I recently ran the numbers on a small board from several PCB shops, both 
>pre-panelized and by allowing them to handle the optimization. In no uncertain terms, 
>each of the hosues told me that had I chosen to do the panelization myself, it would 
>have probably cost me more, due to their knowledge of the "stock" board sizes that 
>they use to create the customer ouput, versus my own ignorance of each of their 
>individual stock sizes and equipment, etc... (And there would have been more effort 
>on my part...more cost..serious cost (manhours)...and more of an opportunity to fudge 
>something while panelizing...more potential for increased cost...)
> Unless you're talking from the perspective of a board house, ie, by "we are 
>performing our first panelization" means that you're the service, not the servicee, 
>then I have to wonder why you're taking this on, aside from a potential academic 
>interest in accomplishing the task, that is.
> regards,
> aj

___________________________________________________________________________            Integrated Controls, Inc.    
   tel: 415-647-0480                        2851 21st Street          
      fax: 415-647-3003                        San Francisco, CA 94110

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