First off, just to clear up some semantics.
There is no such thing as a "board license". You can be:
Board Certified (which entails an unrestricted medical licensure and satisfactory completion of requisite training and passage of the Board Examinations)
and
Licensed (which requires completion of USMLE Step 3 and in some other states, such as Texas, another exam). This is managed at the state level.
Taking time off depends on your contract. Most physicians probably get 4 weeks of paid vacation each year. However, some in-demand specialists, can negotiate for much more.
Taking too much time off can result in loss of clinical skills, licensure and goodwill from your partners or employers. Obviously there are things like FMLA for pregnancy, paternity leave, etc. but most employers and/or business partners would not take kindly to another leaving for 3 months. And if you didn't have paid vacation for that length of time, it might get hard to pay off those student loans and other bills without an income.