Why is electron affinity positive?

[Titan97]

I was reading thermodynamics and about Born Haber cycle. There, I found that the values given for electron affinity are positive.
When an electron is added to flourine, it attains noble gas configuration. So i t becomes more stable. So shouldn't the reaction be exothermic?

 

[Bystander]

https://en.wikipedia.org/wiki/Electron_affinity
Welcome to the wonderful world of sloppy nomenclature in chemistry.

 

[Titan97]

So while calculating lattice energy, the negative of the given value has to be taken?

 

[DrDu]

Electron affinity is especially murky. It makes no sense to talk about it without the sign convention clearly stated. Btw., it's fluorine not flourine.