Multiple Id's in a key of an array

I have an array that has 3 Id's in the key value separated by a ":". The $v value is "on"(checkbox input). I am grabbing the name[Id1:Id2:id] attribute of a checkbox input using jquery. Then sending those values through the url to a function. Then getting the results using a $_POST request.

["Id1:Id2:Id3"]=> string(2) "on"
["Id1:Id2:Id3"]=> string(2) "on"

and so on.

If there is a way separate the id's into their own arrays that would be fantastic.