At the recent IPC meeting in Tempe, AZ. on IPC 6012, Qualification and 
Performance Specification for Rigid Printed Boards, I asked if Para 3.11.8 
b), which reads as follows, is realistic given todays thicker boards and 
higher aspect ratios:

          b) When tested as specified in IPC-TM-650, method 2.4.18.1 ambient 
using 50-100 micrometer (0.002-0.004 in) thick sample, the tensile strength 
shall be no less than 245MPa (36,000 psi) and the elongation shall be no 
less than 6%.

The numbers appear to be directly from WS 6536 and unchanged over the years; 
I personally do not think a 0.125 board with 16 mil holes if it were 6% 
elongation would be very reliable.  I also do not think anyone really would 
try to be at 6%.  BUT I have no data so when I said why not change to a 
"real" number , the team members said show me the data.  That leads me to 
ask the following; anybody have any data?  Is a value of  49,000 psi and 14% 
, any better , or any worse,  than a 42,000 psi and 22%?

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