Get in through the internship program! Go to Career fairs and meet 3M recruiters. That is the best way to get a job at 3M. The internship program really gives you a lot of good experience and you get to meet people in various departments.

Interviewing for full time position. Applied through campus recruiting website. Standard interview questions. Was interviewed by a manager and a recent graduate. Asked the same questions to all candidates. Second round was not needed for decision.