Method for fabricating a thin film build-up structure on a sequentially laminated printed circuit board base

A method for planarizing an outer surface of a printed circuit board, the method comprising:

• placing a pre-formed material on the outer surface of the printed circuit board, the outer surface having at least one of vias and crevices, the pre-formed material including a first sub-material and a second sub-material, the first sub-material being resinous and the second sub-material being non-resinous, the first sub-material being in the form of a sheet, the second sub-material being in the form of a sheet, the first sub-material abutting the second sub-material, the first sub-material abutting the outer surface of the printed circuit board;
• applying an isostatic pressure on the pre-formed material, wherein the second sub-material does not deform;
• and
• laminating the resinous first sub-material with the outer surface of the printed circuit board for at least a portion of time during which the isostatic pressure is applied, wherein, as a result of laminating, the resinous first sub-material substantially fills the at least one of vias and crevices;
• and
• removing the second sub-material completely from the first sub-material after laminating, such that a substantially planar upper surface of the first-sub-material is exposed.