Problem with illuminated SMD tact switches non temperature resistance

How to solve the issue of illuminated SMD tact switch non temperature resistance?

At present ,our SMD tact switch only can be soldered below 245 centi-degree,if operate it higher than the temperature,the switches will be no senstive and no function.

We change the kinds of temperature resistance material,but failed.

How to solve it?is there anyone gimme some advises?thx

And those switches you are using are what?

That seems normal. SMD soldering is normally done at about 200-220C, except for lead-free.
Just set your rework station heat gun to less than 240C.

What does that mean. Just use solder paste and a temp controlled hot-air rework station.
If you don't have that, then don't use SMD parts.