The only reason chips would warp is if they are exposed to heat.
Unless you have the case parked next to a heater vent (or against a wall that you know gets hot with afternoon sun), you're OK.
I have roughly 200 collectible chips, some rather expensive, in AirTites and in display boxes similar to yours. Been that way for a couple years now and I see nothing wrong with any of the chips (they all cam out of the box and AirTites in the last few months for re-scanning).
The only thing I would suggest is to make sure the chips don't get any direct sunlight through a window. The windows of the house and the case will help keep the UV light at bay, but won't stop it entirely. UV light is bad news for artwork and chips. I remember seeing a pic/scan of a chip that had it's colors faded considerably on one side almost certainly due to UV exposure.
Other than that, keep 'em in the case where you can enjoy them on a regular basis!
(BTW, my cases are from the ebay seller grandpajon and I really like them)
[EDIT] Marsha! You beat me to the punch!!!