Not to start a raging controversy, but the concept of 100% electrical 
     test means different things to different shops.  NEVER assume the 
     board shop knows what you want if you specify 100% electrical test.   
     
     You may get only a through hole test ("The customer should know by the 
     price of the fixture that we weren't checking the SMT pads.")  
     
     You may get a "flip" test.  ("We checked it 100%, but our test can't 
     find that open via.")
     
     You may get a double sided test that doesn't check the .015 pitch 
     device.  ("Well, he should know that we can't fixture that without a 
     "flying probe" tester.)
     
     You may get a Golden board test.  ("We didn't know how to handle the 
     IPC format.")
     
     You need to have open communication with your board supplier and avoid 
     any potential for the common misperception of "100% electrical test".  
     Both you and the board shop will be better off.
     
     Regards,
     Jamie Baumgart 


______________________________ Reply Separator _________________________________
Subject: Re: FABRICATION:  E-Test
Author:  [log in to unmask] at SMTPLINK
Date:    2/19/96 5:59 PM


     In my experience with bare boards, the manufacturers seem to know what 
     we mean when we want 100% netlist testing.  They extract netlists from 
     the supplied Gerber data and build a clamshell fixture that can access 
     test points on both sides of the board.  I thought that this was 
     pretty standard from the "100% test" standpoint.
     
     At Hitachi, we don't do PCB design so we don't have expensive software 
     that can do anything with PCB data, but we have purchased a Gerber 
     viewing package that can do everything we need to check the data and 
     make minor modifications.
     
     This software is known as "GerbTool" and costs anywhere from $1500 ~ 
     $5000 depending upon how many bells and whistles you want (we use the 
     $1500 version).  It can be obtained from Wyse Software in Oregon, USA. 
     If you want more details, let me know.
     
     Roger Held
     Hitachi Computer Products
     (405) 360-5500 x142
     [log in to unmask]
     
     
______________________________ Reply Separator _________________________________
Subject: FABRICATION:  E-Test
Author:  [log in to unmask] at Internet-HICAM-OK 
Date:    2/19/96 3:54 PM
     
     
     
We have a question (actually several) from an IPC member in Germany.  If 
you can help please send your replies to me or to TechNet.  Thank you.
     
"It is a known fact that our customers are asking for much higher 
densities and they are using their 'safety belt' by specifying '100% 
electrically tested.'  And with this the whole problem starts.
     
-What is 100% tested?
One way to understand this specification is:  100% of all boards have 
undergone a test.  But the better way would be 100% of all test-points 
have been tested and it was found that there are no opens or shorts 
between these measurement points.
     
-What does the industry need?
The PCB manufacturers would need a so-called net-list that gives the 
location of all end-points which have a significance.  I do know that 
there is test equipment that is checking carefully all those terminal 
points but usually they are too slow for mass production (and crunching 
out several thousand square meter of PCBs every day need fast electrical 
testers...)
     
The usual way of trying to find a 'golden board' becomes less and less 
practical.  It is the customer that has to provide such data.  And here 
my question starts:
     
 -Are you aware of available softwarre for such net-lists? 
 -Is there a working group on this particular subject?
 -How do customers of your industry react to this problem?  (In 
 Germany many of the larger companies are will aware of the problem but 
 they prefer not to 'see' it...)
     
There is a small company in Germany that claims being able to offer a 
software package at about $23,000 for the first and about $6,900 for each 
subsequent programme (apparently each format has to have a separate 
program at each CAD site, so that it is a customer problem rather than a 
PCB manufacturer problem).  Have you heard of similar activities anywhere 
else in USA or Europe?"