wikipedia has a great article on broadcom - https://en.wikipedia.org/wiki/Broadcom

Its history goes back to the 1960's. It is a major semiconductor company that I would say, was part of the ecosystem that made computers and networks possible.

You haven't heard of them because they make too much of everything that makes the fabric of everyday computing.

It's like how you would never really know of the company who made the pipes for your toilet/plumbing.