Dear all, 

We have been fabricating high reliability PCBs for space applications. We are procuring from the contract suppliers also. What is toughest reliability tests as per any standard?. Some does 3 DIP test  @280 Deg C which i could not trace to any known standard. Single float test as per MIL-PRF-55110 may be suitable for olden days wave soldered assemblies. Some does  6 re flow test. Again i am not able to trace to any known standard. 

regards,

R.Saravanan