It's understable that some circuit designers leave their circuit protection to the end, since they barely know what the circuit will even look like in the beginning. The problem is that when they let it go too long, there's no room for it.
We leave what we refer to as "bells and whistles" for the last - those things that are nice to have if time and budget allows. Circuit protection, cooling, and powering the system are biggies that ensure a system will be both robust and reliable and these get our attention from the early stages of design.
tekochip - I've done that too! Especially when I am trying to get as small a footptrint as possible and then whoops - how are we going to mount it sideways in that small space? Times like that I was glad we had an inhouse PCB shop.
Of course the less important steps and additions are left for last, but really, circuit protection is very important to be left for the last stage. Just like the cooling system and the powering system, the circuit system and its protection is equally very crucial. It is arguable that it all depends on the engineers preference, some may wait and do the circuit protection last while some may do it during the beginning or middle of the whole engineering process.
Andy, you are correct the things that are less important are usually left for the last sometimes those things that we consider important but easy as well we leave it for the last as wel. But circuit protection should not be treated lastly because security of anything or any circuit is very important and it should be considered as one of the major step .
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