My boyfriend has a bond of $50,000, he is an student, is is there anyway he can get out without paying anything? if he says that he is applying for a voluntary departure, can he come back in to USA?

The bond is set so that there is assurance that the offender will appear for all court dates. The bailbondsman require at least 10% of that amount and/or some collateral like amn automobile or real estate.  So, getting out without posting a bond is not going to be an option for him. If they allow him to be released to leave the county, it would be unlikely that he would be welcomed back.