Well...at big companies, you are gonna do bitch work for the most part. If you do the software side, its lots of QA and debugging. If you do do some coding, it will be copy and paste code with changing some varables. On the hardware side, it is gonna be lots of testing or CAD work. They will give you boards and you will have to test all them to se if they pass or you will have to input schematics or designs into some cad software. Either way, your first expereince will probably be boring and will porbably not test the limits of your brain.
I was lucky enough to do my first coop at a large yet not really known digital technology company doing firmware. It was design work....but I couldn't do most of it because I spent lots of time learning how to do it. They thought I did a good job with the (non)experience I had and they wanted me to come back.....hell no. I never want to do that type of work again. That said... those were the only types of jobs that came to haunt me after school (I could not find a hardware job). Every single call I got was in reference to my first coop and it kind of wore me out. Luckily, I got a job that is not firmware related, but it is also non electronics related. I guess what I am trying to tell you is look for internships by the experience they will give you and not by the name. In engineering, no one cares if you came from Intel or Microsoft unless you were a senior person there. What they look for is experience.