PCB for fine-pitch flip-chip

Hello All. First time poster. I need to design a PCB which will include a Bumped-die type chip with 6mil (152.4 um) pad pitch. I read somewhere that FR4 type board may not be a good choice for such small footprint. I have not had to deal with boards requiring such small tolerances, so I would apprieciate your comments on manufacturing limitations of such board.

Thanks for any advice.

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