Methods for stereolithographic processing of components and assemblies
View Patent ↗An apparatus and method for providing gross location, planarization, and mechanical restraint to one or more electronic components such as semiconductor dice to be subjected to stereolithographic processing. A double platen assembly including a first platen and a second platen mutually removably connected and configured and arranged to substantially secure an electronic component assembly in position therebetween. At least one of the platens is configured such that a portion of electronic components of a carrier substrate secured by the double platen assembly is viewable for exposure to an energy beam such as a laser beam used to cure a liquid into an associated dielectric stereolithographic packaging structure. Another embodiment includes the use of an adhesive-coated film for holding, locating and securing a plurality of individual electronic components for processing. A method of forming solder balls is also disclosed.
1. A method of forming solder balls on an active surface of at least one semiconductor die, the method comprising:
providing at least one semiconductor die having a plurality of bond pads or trace ends over an active surface thereof;
placing the at last one semiconductor die in an orientation with the active surface thereof facing upwardly;
using a directed beam of radiation to selectively cure portions of a curable liquid material overlying the active surface to form a dielectric layer including apertures formed therethrough located over at least some of the plurality of bond pads or trace ends; and
forming discrete conductive elements in the aperture in contact with the at least some of the plurality of bond pads or trace ends, wherein forming the discrete conductive elements in the apertures further comprises:
forming the apertures to have a lateral dimension larger than a lateral dimension of the plurality of bond pads or trace ends aligned therewith;
placing a volume of solder paste into the apertures sufficient to fill the apertures to an upper extent of the dielectric layer; and
heating the at least one semiconductor die to melt solder in the solder paste and form solder balls projecting above the dielectric layer.
2. The method of claim 1 , wherein placing a volume of solder paste into the apertures comprises placing the solder paste over the active surface of the at least one semiconductor die and removing the solder paste from the active surface above the upper extent of the dielectric layer.
3. The method of claim 2 , wherein providing at least one semiconductor die comprises providing a plurality of semiconductor dice.
4. The method of claim 3 , wherein providing the plurality of semiconductor dice comprises providing a plurality of unsingulated semiconductor dice.