Recently I completed my internship at a firm and I was wondering whether it's a good idea to send invitation to connect on linkedIn to the top management including CEO? Or should I send request to only people who I worked directly with? The only interaction I had with top management was I made a 1 minute presentation about the internship that's it.
Use the Add Note feature when sending a request. Keep it short and simple. The message can vary for person to person, but you should state your intent about wishing to connect.
If you simply send connection requests, some may accept, some may ignore and some may mark your request as "I don't know this person". If a lot of people choose the last option, you risk getting marked as spammer and getting your account suspended.
I wouldn't do that. It makes you look really presumptuous. Unless you worked closely with them or are on 1st name terms (i.e. they know you beyond just "this year's intern").
should I send request to only people who I worked directly with?
I've always stuck to this policy and only added C-level (CTO etc) people that I personally know who have made the request of me.
Is sending LinkedIn invitation to top management team a good idea?
If your presentation to management was relatively recent, you could still send invitations with a note thanking them for attending your presentation, so they have some context.
A good strategy in general, for timing a LinkedIn invite, is to send one right after you've had an interaction.
Your LinkedIn network is more powerful and relevant when you add people you personally know or have worked with.
In general though, adding top management for its own sake is counterproductive, and adds more noise to your network. It can also be awkward if shared contacts assume you know them personally.