You are indeed making "a big leap" changing from the practice of matrimonial law to an intellectual property area. It is important not to rush into such a change and make sure you are making the switch for the right reasons. Is IP where you feel your skills and interests lie? Talk to others who practice in the area and make sure that this move will bring you closer to your ideal job. It is important to keep in mind that switching practice areas will likely mean accepting a cut in salary and in seniority.

A practice switch is difficult in any case. But it is more likely to be doable the more junior the candidate is, the more a candidate has prior relevant experience in the area (whether in law school, in a published note, or in non-legal work) and the more a candidate's current firm is open to the prospect.

The longer you have practiced in an area the more pigeon-holed you become and the harder it is to switch. In most cases the reality is that if you are more than three years out of law school and without any prior experience, it is unlikely that you would be able to make the switch absent the unlikely scenario in which someone presents you an opportunity.

An LL.M. in intellectual property is somewhat unusual. The test as to whether employers value an LL.M. in IP would be to ask the deans and administrators for these programs for placement statistics. How many people with similar backgrounds to yours have used the degree to land a job? How well did they do in the program (and what were their grades and work experience prior to entering the program)? What is the process for on-campus recruiting? What types of firms recruits from the program? Speak with alumni from the program who are currently working and ask them for their advice. If these questions can be answered to your satisfaction, then the program may indeed help you switch practice areas. Best of luck!

Good luck with your search