Jennifer,
    There is no X-out 'standard'.  It's an item of negotiation with your 
board shop.
    The simplistic approach is No X-outs.  Unfortunately depending on the 
technology level of your boards, that will cost you $.  On simple low tech 
boards the difference is typically little but on high tech fine line boards, 
be prepared to pay.
    In real life, shop yields probably run from 80 to 98% depending on the 
degree of difficulty.  You may want to review your assembly structure before 
signing up for added costs.  Your best price per board will be as single 
boards.   Specifying an array will usually cost more because of wasted panel 
space (depending on the board shop's production panel sizes).  Specifying an 
array with no X-outs will cost even more because you are asking your shop to 
scrap the good boards on a panel with X-outs.  The lower the shop's yield, 
the higher the 'No X-out' price.
    If you should decide to go with a 'No X-out' policy, you need to insure 
that the board you are buying fits the daily niche of that supplier.  This 
will keep your 'no X-out' price increase at a minimum.
    As for your insertion equipment, is manual bypass your only option? 
 Some equipment can skip over an X-out if the fiducial targets for that 
board are covered or removed.  If your machine has that capability, you or 
your board shop can disable the fiducials on the X-out boards.
    If allowing X-outs does not cause you a major problem, I would negotiate 
your best price including the maximum number per panel and per lot.  X-outs 
can be very
useful as an educational tool.  If you should have a supplier quality 
concern, reviewing the X-outs included in the shipment can be very 
enlightening.  It can lead to a better understanding of your supplier's 
manufacturing problems as well as improvements in your board designs.

     Norm Dill
 ----------
From: [log in to unmask]
To: [log in to unmask]
Subject: FAB - Defective units on panelized PWBs
Date: Wednesday, January 29, 1997 1:41PM

Is there an industry standard for allowable defects, or x-outs, for 
panelized PWBs?  For instance, if a panel is 8-up, and there are 625 panels 
in the lot (5000 pcs. total in the lot), what is a reasonable defect rate? A 
PWB manufacturer has suggested 1 PWB per panel, and a max. of 10% of the 
panels in the lot.  For this example, that allows 62 panels with an x-out, 
which seems excessive.  The problem with the x-out is that the automatic 
pick and place equipment will stuff the bad PWB unless manually overridden, 
so there will be scrap component costs.   Comments, please.

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to:           *
* [log in to unmask] with <subject: unsubscribe> and no text.        *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************