Method and device for making integrated cooling liquid cavity in printed circuit board

1 . A method for making an integrated cooling liquid cavity in a printed circuit board, characterized in that the method comprises the step of:

inserting a power semiconductor die in a dielectric material that forms a first dielectric layer,

laminating the dielectric material of the first dielectric layer with a dielectric material that forms a second dielectric layer and a thin inner electrically conducting layer on at least corresponding opposite sides of the first dielectric layer, the inner electrically conducting layer being formed by copper,

drilling vias through the laminated copper of the inner electrically conducting layer and dielectric layers,

metallizing the vias in order to form a first printed circuit board,

laminating the dielectric material of the second dielectric layer with a third dielectric layer, a soluble material having a predetermined form and an outer electrically conducting layer on the first printed circuit board,

drilling blind vias through the outer electrically conducting layer to the inner electrically conducting layer,

coating/plating the blind vias,

filling the blind vias with a polymer resin,

injecting solvent in the soluble material in order to dissolve the soluble material and reveal a cavity,

injecting cooling liquid in the revealed cavity.

2 . The method according to claim 1 , characterized in that the method comprises the step, prior injecting the liquid cooling, of coating/plating the revealed cavity.

3 . The method according to claim 2 , characterized in that the soluble material is Polyvinyl alcohol, Butenediol Vinyl Alcohol Co-polymer or inorganic salts in a compressed form.

4 . The method according to claim 1 , characterized in that the soluble material is Polyvinyl alcohol, Butenediol Vinyl Alcohol Co-polymer or inorganic salts in a compressed form.