Bill Gates Drew Anger of Family During Secret Island Trip Ahead of Divorce

The Bill and Melinda divorce has been a done deal for months, TMZ has learned, and they had a plan to announce it back in March ... a plan that included renting a remote, private island where the entire family -- with one BIG exception -- could avoid the media once the announcement was made ... sources with direct knowledge tell TMZ.

Our sources say Melinda Gates rented Calivigny Island in Grenada ... yes, she rented the entire island for $132,000 a night. The plan was for Melinda and the kids, as well as their significant others, to come to the island -- everyone except Bill. We're told everyone in the family already knew Bill and Melinda were divorcing. There was a considerable amount of acrimony associated with the split and we're told virtually everyone in the family took Melinda's side. Another way of putting it ... we're told they were very angry at Bill, and that's why he wasn't invited.

The reason for going to the island ... so no one from the media could reach them and ask about the split when it was announced during their stay.

But, there was a problem ... lawyers for both Bill and Melinda were trying to hash out a divorce settlement and there were still outstanding issues that couldn't be resolved at the time of the trip. We're told Melinda decided to go anyway ... well, with everyone BUT Bill.

So here's the takeaway. First, we're told this was not a friendly split. We're told Melinda and most of the family were furious at Bill for various things they claim he had done.