victor, do you mean fracture of the laminate (cratering)?  it is not  
what spec calls, it is what your design process dictates IMHO.   
normally, you have 5 or 6 reflow, top and bottom SMT, (2x) selective  
BGA (if it is high value added parts) attach (you test SMT 1st before  
that attach.  That could be a temperature sensitive part too (1x),  
underfill  cure (if you use reflow cure for the fast cure underfill)  
(1x), selective reflow or edge connector attach if in need (1x)  plus  
allowable 2X rework maximum.  if your PWB can not withstand the 6x  
reflow as design required, either your design MFG process need to  
change, PWB need to change, or you work until your back off to  
eliminate the rework (basically, your PWA is throw away if any defect  
present, if it is cheap assembly, no big deal.  If it is very pricy  
and limited qty (high mix, small volume, like aircraft control  
board), you change PWB and design.  Just make sure your design  notes  
(MFG  instruction) red lined "any rework is not allowed" and get  
program mgr signed off on it.  Otherwise, you have a big headache and  
finger  pointing when field return  piled up (down to the line,   
someone somewhere want  to repair it, "just a touch up").  my 1.4  
cents. (by the way, your reliability qual should be using reworked  
part, for shake and bake, thermal shock, etc. worst case).
jk
On May 1, 2017, at 4:07 PM, Jose A Rios wrote:

> What exactly do you mean by cratering? 6012/a600 does not use that  
> exact term, it uses cracks, plating separations and lifted lands.  
> Thats why i ask. Also any acceptance criteria in 6012/a600 for  
> pth's and annular rings after thermal stress are after 1x thermal  
> stress, not 6x.
>
> Sent from my iPhone
>
>> On May 1, 2017, at 3:58 PM, "[log in to unmask]"  
>> <[log in to unmask]> wrote:
>>
>> Fellow TechNetters;
>>
>>   Is PTH annular ring pad cratering permitted after Thermal  
>> Stress, 6x?   What is the allowance?  I don't have a copy of IPC- 
>> A-600 Rev F before me.
>>
>> Victor,