Hi. I am doing a PhD in engineering. My work is related to Electronics and Physics. I have only spent most of my times in academia and worried about industry experience. I might manage to get an unpaid internship at a semiconductor fab but undecided about going for it . Can anyone help me if doing such a thing improves future employability or it is more important for PhD job seeker to show their involvement with academia and conference/journal publications.

I think you really should do an internship to build your commercial awareness. Even amongst undergraduates applying for grad schemes it is a distinct advantage to have done an internship/summer placement in the field of work you want to work in. So I think you will find it a lot harder to persuade interviewers to take you on if you do not have any commercial experience. So go for it and I also think you'll find it a refreshing change from academic work. Don't worry about it being unpaid - it is an investment in your career and your future.