Thanks for your help guys.
Good to know about strain relief, tie-down, un-plated holes in the PCB which help me in getting out-of this issue.
I would like to know if I could find the PCB fab specifications on what constitutes a industrial, commercial or automotive grade PCBs. Does anyone knows what are the major characteristics that define these groups?? Here I am thinking few below and what should I choose for these while uploading my Gerber data:
a. Copper thickness, b. dielectric material, c. TG, d. solder mask, e. Board thickness
Thanks in advance.