I was an engineering manager for a large aerospace company. We would only offer internships to upcoming seniors and above. Before that, the student just didn’t have the skills we were looking for. We also would use the internships as basically 3 month interviews for permanent employment.
One other fact about internships at the big companies. The grade point requirement for an internship was higher than for permanent employment. It was a matter of the number of internships we offered and the number of applicants we got.
In college, I got involved in undergraduate research during the school year. That led directly to summer work at the college doing that same research.
As far as getting experience for a permanent job once he graduates, an internship in the upper division for one year is good enough experience. You want to be able to prove that you know what it is like to be responsible and show up for work and be able to work the whole day. At this point, any kind of employment is good.