Process of surface-mounting three-dimensional package structure electrically connected by prepackaged metal

A process of a surface-mounting three-dimensional package structure electrically connected by a pre-packaged metal, comprising:

• step 1, taking a metal sheet;
• step 2, forming a metal-pillar circuit layer on a surface of the metal sheet by electroplating:
• forming a circuit layer on the surface of the metal sheet by electroplating and forming a conductive copper pillar above the circuit layer by electroplating;
• step 3, performing plastic packaging on the metal-pillar circuit layer:
• protecting the metal-pillar circuit layer on the surface of the metal sheet by a molding compound;
• step 4, performing windowing:
• windowing a required portion of the plastically-packaged metal-pillar circuit layer;
• step 5, removing the metal sheet;
• step 6, fitting the metal-pillar circuit layer and performing plastic packaging:
• taking a substrate on which a chip is surface-mounted, printing the metal-pillar circuit layer on the substrate by a solder paste or fitting the metal-pillar circuit layer to the substrate by a conductive adhesive for partially electrical connection with the substrate, performing the plastic packaging on an exposed portion of the chip for protection, and performing grinding to expose an upper surface of the metal-pillar circuit layer, wherein the windowed portion exactly accommodates the chip on the substrate;
• step 7, surface-mounting a passive device, and performing packaging and ball-mounting:
• mounting the passive device on the upper surface of the metal-pillar-circuit layer, performing plastic packaging on the surface of the substrate, on which the passive device is mounted, and performing ball-mounting on a lower surface of the substrate;
• step 8, performing cutting:
• cutting the plastically-packaged substrate into single products.