Frances Bean Cobain's estranged husband says he won't have a penny to his name without her ... so he's asking a judge to make her pay up.
Isaiah Silva is requesting spousal support, and according to the docs he wants a ton of it -- nothing less than $25k a month.
Isaiah says he left a steady job when they got married and Frances promised to cover a bunch of his monthly expenses, including paying private school and housing bills for his child from a previous relationship.
Now, he says Frances wants to renege on those commitments. Isaiah claims Frances has upwards of $100 mil in her dad's estate, and says he deserves half of the money she earned off business deals made during the 2 year marriage. He says there's no prenup.
Frances made it clear in her divorce docs ... the Kurt Cobain money is hers alone and not Isaiah's -- but she is open to paying some spousal support.