Method for making a stacked package semiconductor module having packages stacked in a cavity in the module substrate
View Patent ↗A stacked die chip scale package, in which a stacked die assembly is mounted within a cavity in a module substrate. In some embodiments certain of the die are stacked on a front side of a stacked die assembly substrate, and the stacked die assembly substrate is inverted in the cavity and the substrate is electrically interconnected to a front side of the module substrate; others of the die are stacked on the back side of the stacked die assembly substrate, and are interconnected by wire bonds to the front side of the module substrate. In some embodiments, the cavity is covered by a heat sink, and the stacked die assembly is mounted onto the heat sink. Also, methods for making the module are provided.
1. A method for making a stacked package semiconductor module, comprising:
providing a stacked die assembly substrate;
affixing at least a first die on a front side of the assembly substrate and electrically connecting the die to sites at the front side of the assembly substrate to form a package;
providing a module substrate having a front side and a back side and an opening through, the opening having a length and width at least as great as the length and width of the package;
reversibly affixing the module substrate onto a stage;
inverting the package and situating the package at least partly within the opening;
mounting at least a first additional die at the back side of the assembly substrate to form a stacked die assembly, and electrically connecting the additional die to sites at the front side of the module substrate;
encapsulating the stacked die assembly and interconnections and the front side of the module substrate; and
removing the module from the stage.
2. The method of claim 1 , further comprising attaching second-level interconnect solder balls at sites in the back side of the module substrate.
3. The method of claim 1 wherein the step of situating the package includes removably affixing a top surface of the package to the stage within the opening.
4. The method of claim 1 wherein the step of providing the substrate includes providing a support spanning the opening at the back side of the substrate; in some such embodiments the step of situating the package includes affixing a top surface of the package to the support within the opening.